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Paul, Martin Andrew. "Arc sawing of nickel based superalloys." Thesis, University of Birmingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.396243.
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Liljengren, Erik. "Adaptive sawing : - Yield of a concept in reality." Thesis, Linköping University, Linköping University, Wood Technology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-20899.
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Glue board is the base for much solid wood furniture produced by the IKEA-owned companySwedwood. Glue board is glued together from lamellas which can be produced in different waysbut in all cases is produced from boards coming from a saw-mill. In a saw-mill there aredifferent techniques for producing boards from logs. This thesis is about the Adaptive sawingconcept and its implementation at the Swedwood site in Kostomuksha. The idea with the conceptis to raise the output from the raw material, the yield. This is partly achieved by edging away islittle as possible from the boards in the saw-mill. The boards in the saw-mill are sawn in a waynot unlike through-sawing. When brought to the glue-board factory they are scanned in order tooptimise how to rip out as much lamellas as possible. The ripped lamellas are then cross-cut intodifferent sizes which later are glued to glue board. The objective of this thesis is to examine theyield from log to glue board for the log classes 135-148 mm and 110-120 mm, to try to improveit and to identify problem factors.In order to achieve that it was necessary to be sure of the volume figures at all stages. Theincoming volume was given by the scanner at the log sorting; effort was therefore put down tomake sure the figures could be trusted. For the smaller log class the logs were instead measuredby hand and the volume was calculated. The logs were then sawn in the saw-mill. This was donewith a low production speed and some problems were noted compared with when sawing with astandard technique. The absence of edging was the main reason for these problems. The saw-millline was deemed inappropriate for sawing the smallest log class but could handle the 135 -148mm class and the yield for that class was in line with what could be expected.In the lamella production line some minor problems were noted and the boards from the fourdifferent batches from the 135 – 148 mm log class got different yields mainly due to differencesin wood quality. The yield from log to glue board for these four batches varied from 17.6 % to21.5 % with an average at 19.3 %. The yield was lower than what was achieved for earlieradaptive sawing test batches on other places. Those tests were however done on other diameterclasses and with material that was slightly different than the one in Kostomuksha. Simulationswere done to check how much the yield could be raised if other lamella widths than just thestandard 46 mm lamella width was used. A raise to an average of 20.9 % could then be expectedwhen using the lamella widths 46, 55 and 60 mm.A similar simulation was done for the adaptive material that was produced from the 110 – 120mm log class. The total yield for that material rose from 19.4 % to 22.4 % when using morelamella widths. Lamellas from this material were tested as there was fear, that they would notmeet the standards for glue board production. This did however not prove to be the case. To usethe lamella production for producing such material is however not ideal, since a very smallvolume is produced.
Limfog är basen för de massivträmöbler som görs av IKEA:s helägda leverantör Swedwood.Limfog består av lameller som kan produceras på olika sätt. Oavsett produktionsteknik görs deav brädor som kommer från ett sågverk. På sågverket finns det också sågsätt för att såga utbrädor ur stockar. Det här examensarbetet behandlar konceptet adaptiv sågning och dessimplementering på Swedwoods anläggning i Kostomuksha. Den grundläggande idén medkonceptet är att höja utbytet på råvaran. Detta uppnås bland annat genom att så lite som möjligtkantas bort på brädorna i sågverket. Brädorna sågas upp med vad man kan kalla genomsågning.När brädorna sedan förts till limfogsfabriken scannas de så att så mycket som möjligt ska kunnafås ut av varje bräda i form av lameller. Lamellerna som sågats ut kapas sedan upp i olikastorleksklasser beroende på kvalitet. Dessa limmas sedan ihop till limfog. Syftet med det härexamensarbetet är att ta fram utbytet från stock till färdig limfog för stockklasserna 135 – 148mm och 110 – 120 mm. Dessutom ska problemfaktorer identifieras och utbytet om möjligt höjas.För att uppnå detta syfte var det nödvändigt att ha säkra siffror för alla inblandade volymer isamtliga skeden. Stockarnas volym gav av en mätram vid timmersorteringen. Mycket kraft lasdärför ner för att säkerställa att dessa siffror var trovärdiga. Stockarna i den mindrediameterklassen mättes istället för hand och volym beräknades utifrån mätningarna. Stockarnasågades sedan på sågverket. Produktionshastigheten under sågningarna var låg och en delproblem i jämförelse med när sågning sker på mer traditionellt vis kunde noteras. Avsaknaden avkantning var huvudorsaken till dessa problem. Sågverkslinan visade sig vara olämplig för attsåga den mindre stockklassen, men kunde hantera stockar med en diameter på 135 – 148 mm.Utbytet för dessa var i linje med vad som kunde förväntas.I lamellproduktionslinjen kunde en del smärre produktionsproblem noteras och brädorna från defyra olika omgångarna av 135 – 148 mm stockar fick olika utbyte mest beroende på skillnader iråvarukvalitet. Utbytet från stock till limfog varierade från 17,6 % till 21,5 % och låg i snitt på19,3 %. Detta utbyte var lägra än vad som uppnåtts för adaptiv sågning på andra platser vidtidigare tester. De testerna utfördes dock på andra diameterklasser och det är därför svårt att raktav jämföra siffrorna. Dessutom kan råvaran ha varit något annorlunda. För att se hur mycketutbytet kunde höjas om andra lamellbredder användes förutom bara 46 mm, gjordessimuleringar. Totalutbytet kunde då höjas till i snitt 20,9 % i fall lamellbredderna 46, 55 och 60mm användes.En likadan simulering gjordes på materialet som producerades från diameterklassen 110 – 120mm. Totalutbytet för denna klass steg från 19,4 % till 22,4 % när fler lamellbredder användes.Eftersom det fanns viss oro att lamellerna skulle hålla lägre kvalitet övervakades de ilimfogsproduktionen. Oron visade sig obefogad. Att producera lameller från den diameterklassenär dock inte idealt eftersom den producerade volymen blir så liten.
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Mohammadpanah, Ahmad. "Flutter instability speed of guided splined disks, with applications to sawing." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/52060.
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In this thesis the vibration characteristics of guided splined saws are studied, both analytically and experimentally. Significant insights into the complex dynamic behavior of guided splined saws are presented by analytical investigation of the dynamic behaviour of spinning splined disks and then by conducting idling and cutting experimental tests of guided splined saws. Cutting tests are conducted at different speeds, at critical, supercritical, and post flutter speeds of a guided splined saw. The cutting results are compared to determine the stable operation speeds for guided splined saws.
For the analytical studies, the governing linear equations are derived for the transverse motion of a constant speed spinning splined disk. The disk is subjected to lateral constraints and loads. Rigid body translational and tilting degrees of freedom are included in the analysis of total motion of the spinning disk. Also considered in the analyses are applied conservative in-plane edge loads at the outer and inner boundaries. The numerical solution of these equations is used to investigate the effect of the loads and constraints on the natural frequencies, critical speeds, and stability of the spinning disk. The sensitivity of the eigenvalues of the splined spinning disk to the in-plane edge loads is analyzed by taking the derivative of the spinning disk’s eigenvalues with respect to the applied loads. This analysis contains an evaluation of the energy transfer from the applied loads to the disk vibrations and is used to examine the role of critical system components in the development of instability.
Experimental results are presented that support the validity of the analysis. The experimental results indicate that flutter instability occurs at speeds when a backward travelling wave of a mode meets a reflected wave of a different mode. The maximum stable operating speed of the rotating splined disk is defined as the initiation of flutter. Flutter instability speeds of splined saws of various sizes were computed and verified experimentally. Then flutter speed charts of splined saws were developed which provides primary practical guide lines for sawmills to choose optimum blade diameter, eye size, blade thickness, and a stable rotation speed.Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate
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Woxblom, Lotta. "Warp of sawn timber of Norway spruce in relation to end-user requirements : quality, sawing pattern and economic aspects /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1999. http://epsilon.slu.se/avh/1999/91-576-5860-9.pdf.
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Wright, D. N. "The development of a rock classification system for use with diamond tools." Thesis, University of Nottingham, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339562.
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Gehring, Junior Waldemar. "Desempenho do stellite como material de ferramenta no serramento da madeira /." Guaratinguetá : [s.n.], 2011. http://hdl.handle.net/11449/94387.
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Orientador: Marcos Tadeu Tibúrcio GonçalvesBanca: Manoel Cleber de Sampaio Alves
Banca: Ivaldo de Domenico Valarelli
Resumo: O presente trabalho apresenta uma análise de parâmetros para a seleção de material de ferramenta de corte indicando o uso do Stellite como alternativa para obter melhor produtividade nas serrarias de desdobro de madeiras no Brasil. Para tanto, estudou-se as inter relações entre a propriedades físico químicas de espécies de madeira tropical e o processamento mecânico de desdobro das mesmas, além das origens do desgaste dos materiais empregados como ferramenta de corte. Foram realizados experimentos para determinar as características de densidade básica, teor de sílica e acidez de algumas espécies de madeira tropicais. As espécies estudadas foram: Angelim vermelho (Dinizia excelsa Ducke), Angelim pedra (Hymenolobium petraeum Ducke), Maçaranduba (Manilkara huberi (Ducke) Chevalier), Itaúba (Mezilourus lindaviana Schwacke & Mez), Mandioqueira lisa (Qualea albifloraWarm), Mandioqueira escamosa (Qualea paraensis Ducke) e Quaruba fissurada (Vochysia maxima Ducke). Para tais experimentos, as amostras foram colhidas e gerenciadas nas regras do manejo sustentável. Após a caracterização das espécies e análise do grau de abrasividade das mesmas, foi escolhida a espécie "Maçaanduba" para os testes de desempenho em processos de usinagem e, nas condições de corte e processamento utilizadas, relata-se de forma comparativa os apectos teóricos citados na revisão bibliográfica. Como resultado, pode-se comprovar que o material Stellite apresentou desempenho superior relativo ao desgaste e avarias, quando comparado com outros materiais como o metal duro, além de demonstrar um efetivo ganho de produtividade no serramento de toras de madeira de maçaranduba
Abstract: This study presents an analysis of selection parameters for cutting tool materials, indicating Stellite alloy as a substitute to improve sawmill productivity in Brazil. For that purpose, it was studied the interrelationship between the physical and chemical properties of tropical wood and the wood cutting mechanical process, as well as the origins of wear in cutting tool materials. Some tropical woods were tested for specific, gravity, silica content and acidity. The following species were studied: Angeli vermelho (Dinizia excelsa Ducke), Angelim pedra (Hymenobolobium petraeum Ducke), Maçaranduba (Manilkara huberi (Ducke) Chevalier), Itaúba (Mezilaurus lindaviana Schwacke & Mez), Mandioqueira lisa (Qualea albiflora Warm), Mandioqueira escamosa (Qualea paraensis Ducke) e Quaruba fissurada (Vochysia maxima Ducke). For those experiments, the samples were collected and processed following sustainable management practices. After characterization and analysis of abrasion degree of those species, the Manilkara huberi (Ducke) Chevalier was selcted for the machining process performance tests. Under the cutting and processing conditions established, the theoretical aspects cited in the references are comparatively reported. As a result, it was possible to demonstrate that the Stellite alloy displayed better wear and tear perfomance when compared with other materials sucha as hard beside demonstrating effective productivity gain when sawing Manilkara huberi (Maçaranduba) wood
Mestre
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Ashford, Sheridan. "Validation of a Redwood Sequoia Sempervirens (D. Don) Endl Butt Log Sawing Simulator." Thesis, University of Canterbury. School of Forestry, 2013. http://hdl.handle.net/10092/9904.
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Redwood (Sequoia sempervirens (D. Don) Endl.) has been identified as a species with considerable potential for plantation forestry in New Zealand. Investment decisions in high value alternate species must be based on accurate wood quality and value predictions. There is an opportunity to extend non-destructive evaluation tools available to redwood growers, and to present the outputs of the growth model by log products and sawn timber.
A redwood pruned buttlog sawing simulator has been developed however the simulator had not been tested with real data. Twelve redwood trees from Mangatu estate were selected for a sawing study; these logs were reconstructed and run through the sawing simulator. Computerised log processing was used to produce simulated pruned log sawing outturn from the redwood Buttlog Sawing Simulator, and results were compared to real results from a sawing study.
The objective of the study was therefore to determine how well the simulator matched volume and grade out-turn from twelve logs. This study found the many inconsistencies between simulated data and real data; particularly related to log size. While this study was unsuccessful in validation of the redwood sawing simulator, it provides initial insight into the simulators strengths and short comings.
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Lindner, Berndt Gerald. "Determining optimal primary sawing and ripping machine settings in the wood manufacturing chain." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86672.
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Thesis (MEng)--Stellenbosch University, 2014.ENGLISH ABSTRACT: For wood manufacturers around the world, the single biggest cost factor is known to be its raw material. Thus maximum utilisation, specifically volume recovery of this raw material, is of key importance for the industry. The wood products industry consists of several interrelated manufacturing steps for converting trees into logs and logs into finished lumber. At most primary and secondary wood processors the different manufacturing steps are optimised in isolation or based on operator experience. This can lead to suboptimal decisions and a substantial waste of raw material. The objective of this study was to determine the optimal machine settings for two interrelated operations, namely the sawing and ripping operations which have traditionally been optimised individually. A model, having two decision variables, was developed which aims to satisfy market demand at a minimal cost. The first decision was how to saw the log supply into different thicknesses by choosing specific sawing patterns. The second was to decide on a rip saw’s settings, namely part priority values, which determines how the products from the primary sawing operation are ripped into products of a certain thickness and width. The techniques used to determine the machine settings included static simulation with the SIMSAW software to represent the sawing operation and mixed integer programming to model the ripping operation. A metaheuristic, namely the Population Based Incremental Learning algorithm, was the link between the two operations and determined the optimal settings for the combined process. The model’s objective function was formulated to minimise the cost of production. This cost included the raw material waste cost and the over or under production cost. The over production cost was estimated to include the stock keeping costs. The under production cost was estimated as the buy-in cost of purchasing the under supplied products from another wood supplier. The model performed well against current decision software available in South Africa, namely the Sawmill Production Planning System package, which combines simulation (SIMSAW) and mixed integer programming techniques to maximise profit. The model added further value in modelling and determining the ripping priority settings in addition to the primary sawing patterns.
AFRIKAANSE OPSOMMING: Die grootste enkele koste vir houtprodukvervaardigers wêreldwyd is dié van hulle roumateriaal. Die maksimale gebruik van rou materiaal, of volume herwinning, is dus van primêre belang vir hierdie industrie. Die vervaardigingsproses in die houtprodukte-industrie bestaan uit ‘n verskeidenheid interafhanklike stappe om bome na stompe te verwerk en stompe na eindprodukte. By meeste primêre -en sekondêre houtvervaardigers word die verskillende vervaardigingsstappe in isolasie ge-optimeer. Hierdie praktyk lei tot sub-optimale besluite en ‘n vermorsing van roumateriale. Die doelwit van hierdie studie was om die optimale masjienverstellings vir twee interafhanklike prosesse, die primêre -en kloofsaag prosesse, te bepaal. Tradisioneel word hierdie twee prosesse individueel optimeer. ‘n Model met twee besluitnemingsveranderlikes is ontwikkel wat poog om die markaanvraag te bevredig teen ‘n minimum koste. Die eerste besluit was watter saagpatroon gekies moet word om die stompe in die regte dikte produkte te saag. Die tweede besluit was wat die kloofsaagstellings, ook bekend as prioriteitswaardes, moet wees sodat die regte wydte produkte gesaag word. Die tegnieke wat gebruik is sluit statiese simulasie met SIMSAW sagteware in om die primêre saagproses te modelleer en gemengde heelgetalprogammering (“mixed integer programming”) om die kloofsaagproses te modelleer. ‘n Metaheuristiek genaamd die “Population Based Incremental Learning” algoritme,was die skakel tussen die twee operasies om die optimale masjienstellings vir die proses te bepaal. Die model se doelfunksie was geformuleer om die koste van produksie te minimeer. Hierdie koste sluit die roumateriaal afvalkoste en die kostes van oor -en onderproduksie in. Die oorproduksiekoste was ‘n skatting van die voorraadkostes. Die onderproduksiekoste was ‘n skatting van die koste om voorraad van ‘n ander verskaffer aan te koop. Die model het goed opgeweeg teen die beskikbare besluitnemingssagteware in Suid Afrika, die “Sawmill Production Planning System”, wat ‘n kombinasie van SIMSAW en ‘n gemengde heelgetalprogrammeringstegniek is. Die model het verder waarde toegevoeg deur die kloofsaag se prioriteitswaardes te modelleer saam met die primêre saagpatrone.
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Pogue, Vanessa Ann. "Measurement and analysis of wire sawing induced residual stress in photovoltaic silicon wafers." Thesis, Georgia Institute of Technology, 2016. http://hdl.handle.net/1853/55071.
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The manufacturing process of a photovoltaic Si wafer comprises of first a high temperature heating process to produce a Si ingot from polycrystalline Silicon, which is then cut into bricks and subsequently sawn into wafers using a wire saw. These processes create residual stresses both from the thermal gradient induced by solidification and from either the rolling-indenting or scratching-indenting processes caused by the type of wire saw used. The objective of this research is to study silicon wafer residual stress as a result of the typical industry manufacturing processes and by doing so, better understand the mechanical properties that lead to increased fracture. This thesis aims to quantify the amount of residual stress generated by the solidification/thermal gradient produced during the casting of Si ingots separately from the residual stress generated by the wire sawing process. Samples from industry are used to compare the effects of the manufacturing processes on residual stress in multi-crystalline silicon (mc-Si) wafers including the effects of fixed abrasive diamond wire sawing (DWS) vs. loose abrasive (LAWS) slurry wire sawing used in the wafering process.
Near-infrared birefringence polariscopy and polarized micro-Raman spectroscopy are used to study wafer residual stresses within grains and at grain boundaries in mc-Si as a function of etch-depth. While near-infrared birefringence polariscopy allows for the measurement of full-field maximum shear stress, micro-Raman spectroscopy provides decomposition of the stress tensor into both principal and shear in-plane stress components. Consequently, regions of high tensile stress, which are detrimental to the mechanical integrity of the wafer, can be easily identified.
In addition to the mechanical characterization, the residual stress produced by the thermal gradient/solidification process for multi-crystalline Si wafers was also correlated to electrical performance of mc-Si wafers using photoluminescence.
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Tian, Jifang. "Self-excited vibrations of rotating discs and shafts with applications to sawing and milling." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0022/NQ34634.pdf.
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Gehring, Junior Waldemar [UNESP]. "Desempenho do stellite como material de ferramenta no serramento da madeira." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/94387.
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O presente trabalho apresenta uma análise de parâmetros para a seleção de material de ferramenta de corte indicando o uso do Stellite como alternativa para obter melhor produtividade nas serrarias de desdobro de madeiras no Brasil. Para tanto, estudou-se as inter relações entre a propriedades físico químicas de espécies de madeira tropical e o processamento mecânico de desdobro das mesmas, além das origens do desgaste dos materiais empregados como ferramenta de corte. Foram realizados experimentos para determinar as características de densidade básica, teor de sílica e acidez de algumas espécies de madeira tropicais. As espécies estudadas foram: Angelim vermelho (Dinizia excelsa Ducke), Angelim pedra (Hymenolobium petraeum Ducke), Maçaranduba (Manilkara huberi (Ducke) Chevalier), Itaúba (Mezilourus lindaviana Schwacke & Mez), Mandioqueira lisa (Qualea albifloraWarm), Mandioqueira escamosa (Qualea paraensis Ducke) e Quaruba fissurada (Vochysia maxima Ducke). Para tais experimentos, as amostras foram colhidas e gerenciadas nas regras do manejo sustentável. Após a caracterização das espécies e análise do grau de abrasividade das mesmas, foi escolhida a espécie Maçaanduba para os testes de desempenho em processos de usinagem e, nas condições de corte e processamento utilizadas, relata-se de forma comparativa os apectos teóricos citados na revisão bibliográfica. Como resultado, pode-se comprovar que o material Stellite apresentou desempenho superior relativo ao desgaste e avarias, quando comparado com outros materiais como o metal duro, além de demonstrar um efetivo ganho de produtividade no serramento de toras de madeira de maçaranduba
This study presents an analysis of selection parameters for cutting tool materials, indicating Stellite alloy as a substitute to improve sawmill productivity in Brazil. For that purpose, it was studied the interrelationship between the physical and chemical properties of tropical wood and the wood cutting mechanical process, as well as the origins of wear in cutting tool materials. Some tropical woods were tested for specific, gravity, silica content and acidity. The following species were studied: Angeli vermelho (Dinizia excelsa Ducke), Angelim pedra (Hymenobolobium petraeum Ducke), Maçaranduba (Manilkara huberi (Ducke) Chevalier), Itaúba (Mezilaurus lindaviana Schwacke & Mez), Mandioqueira lisa (Qualea albiflora Warm), Mandioqueira escamosa (Qualea paraensis Ducke) e Quaruba fissurada (Vochysia maxima Ducke). For those experiments, the samples were collected and processed following sustainable management practices. After characterization and analysis of abrasion degree of those species, the Manilkara huberi (Ducke) Chevalier was selcted for the machining process performance tests. Under the cutting and processing conditions established, the theoretical aspects cited in the references are comparatively reported. As a result, it was possible to demonstrate that the Stellite alloy displayed better wear and tear perfomance when compared with other materials sucha as hard beside demonstrating effective productivity gain when sawing Manilkara huberi (Maçaranduba) wood
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Filho, Clébio Goulart Coimbra. "Relação entre processo de corte e qualidade de superfícies serradas de granitos ornamentais." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/18/18132/tde-07122006-082849/.
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A etapa de serragem de blocos (desdobramento) de granitos ornamentais considerando uma visão integrada entre as propriedades das rochas e o desempenho de máquinas, equipamentos e insumos, pode contribuir de forma fundamental para o aprimoramento do setor de rochas ornamentais. Mesmo com crescimentos marcantes na produção e exportação e grande avanço tecnológico, o empirismo predomina no processo produtivo aumentando a possibilidade de desperdícios, quebra de equipamentos, defeitos nas chapas, etc. Para minimizar a utilização da prática e otimizar o processo produtivo, este trabalho objetiva a correlação entre parâmetros operacionais e características tecnológicas das rochas para melhorar a qualidade das chapas produzidas. Foram acompanhadas as serragens e coletadas amostras de três materiais de grande demanda e efetuadas análises petrográficas, determinações da rugosidade e tratamentos estatísticos que, conjuntamente, com dados operacionais provenientes das serragens, avaliou-se a qualidade das superfícies serradas. Este estudo comprova a lacuna existente entre os estudos relacionados às variáveis envolvidas no processo de corte e as características petrográficas e da necessidade de uma pesquisa aplicada que permita a definição de procedimentos adequados na etapa de beneficiamento primário de granitos ornamentais, com a participação intensa das empresas que atuam nesse ramo da economia.The industry of ornamental and dimension stone can be improved by the global and integrated overview of stone properties and performance machines, equipment and insums. Although with excellent growth in production and exportation and great technological advance, the empirism predominates in the productive process, a practice that might leads to loses, failures of equipment, defects in final product and other problems. Pointing this question are presented and correlated operational parameters of the sawing processes and technological properties of rocks, intending to contribute with the optimization of the productive processes and improve quality of slabs. Three varieties of granites were selected, sampled and subjected to petrographical analysis and rugosity evaluation. For each rock the block cut processes using gang saws was accompanied. The set of laboratorial and processes data was treated statistically and analyzed expecting to evaluate the quality of sawed surface slabs. The results obtained are not conclusive and pointing the necessity of future studies to understanding the effective relations between the petrographical features and processes procedures during block cut step in the dimension stone industry. Is expected this approach resulting in better guides to improve the quality of slabs and minimize loses during the processes.
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Carton, Louise. "Mechanical properties of thin silicon wafers for photovoltaic applications : Influence of material quality and sawing process." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI107.
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Le wafer de silicium cristallin est le composant clé de la cellule solaire et représente une part significative du prix du module photovoltaïque. La réduction de l’épaisseur des wafers offre donc une voie privilégiée pour diminuer les coûts de production de l’énergie solaire. Le maintien de faibles taux de casse lors de la manipulation de ces fines plaquettes reste cependant un obstacle majeur. Dans ce contexte, il est primordial d’améliorer notre compréhension des mécanismes de fragilisation et de rupture des wafers. Ce travail étudie les propriétés mécaniques des wafers de silicium obtenus par découpe au fil diamanté. Nous avons développé une méthodologie de caractérisation mécanique adaptée à l’extrême fragilité de ces échantillons, en combinant des essais de rupture en flexion 4-lignes, biaxiale ainsi que des sollicitations dynamiques par chocs. En parallèle, des simulations par la méthode des éléments finis ont été implémentées afin de mieux comprendre les phénomènes en jeu. Des essais réalisés sur des échantillons bruts de découpe, attaqués chimiquement et recuits thermiquement ont révélé que l’endommagement le plus critique pour la défaillance mécanique se situe dans une couche de faible épaisseur inférieur à 3 µm) sous la surface, dont les propriétés sont contrôlées par l’étape de découpe. Au travers d’une vaste campagne de caractérisation sur des wafers de différentes épaisseurs (de 180 à 100 µm), nous avons montré que l’amincissement des plaquettes permet un gain de flexibilité sans diminution de la résistance mécanique intrinsèque, mais qui s’accompagne d’un risque plus élevé de rupture suite à un impact sur la tranche. Enfin, nous avons mis en évidence que les défauts structurels dans le silicium multicristallin et mono-like sont indirectement responsables de la diminution de la résistance à rupture des wafers : la difficulté accrue du fil à traverser ces défauts se traduit par des microfissures plus profondesThe crystalline silicon wafer is the key component of the solar cell and accounts for a significant portion of the total photovoltaic (PV) module cost. Reducing wafer thickness is therefore a privileged pathway to decrease solar energy production costs. Maintaining low breakage rates when processing such thin samples remains however challenging. In this context, it is essential to improve our understanding of the mechanisms responsible for wafer embrittlement and failure. This work investigates the mechanical properties of silicon wafers obtained using diamond wire sawing. We developed a mechanical characterization methodology suited for these thin, brittle samples, combining destructive tests with 4-line bending, biaxial bending and dynamic impacts. In parallel, finite element simulations were implemented to better understand the underlying phenomena. Tests performed on as-cut, chemically etched and annealed samples revealed that the most critical damage regarding mechanical failure is located within a thin subsurface layer (less than 3 µm), which properties are controlled by the sawing step. Through an extensive characterization campaign on wafers with different thicknesses (from 180 to 100 µm), we demonstrated that thinner samples exhibit an increased bending flexibility without alteration of their intrinsic mechanical strength, accompanied however by a higher risk of failure following an impact. Finally, we highlighted that the presence of structural defects in multicrystalline and mono-like silicon is indirectly responsible for the lower fracture strength of the wafers: the increased suffering of the diamond wire when cutting through these defects generates indeed deeper microcracks
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Hussmo, Daniel. "Dammhantering vid väggsågning." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Produktutveckling, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-35033.
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Vid väggsågning i betong uppkommer det mycket damm. Detta damm tas till viss del upp av det vatten som appliceras för att kyla klingan under sågning, vilket leder till en så kallad slurry. Slurryn samt dammet behöver efter avklarad sågning tas upp vilket resulterar i extra arbetsmoment för brukaren av sågen. Det största problemet här är dock det damm som inandas vilket kan leda till sjukdomar såsom silikos. Dessa sjukdomar kommer i framtiden antagligen leda till nya lagkrav kring hur dammet behöver tas hand om innan brukaren kan andas in det. Syftet med studien har därmed varit att utreda hur damm och slurry kan tas upp vid väggsågning. Problemet med väggsågning gentemot andra former av bearbetning i betong har varit svårigheten att täta av gentemot ytan som bearbetning sker i. I fallen med borrning är det tillexempel möjligt att sluta av området och skapa undertryck som då suger upp damm och slurry. För att ge en grund till konceptframtagning utfördes en observation av väggsågning för att skapa förståelse för hur dammet och slurryn beter sig under sågning. Vidare utfördes även en fallstudie för att samla data gällande hur problemet löses idag samt samla punkter från industrin gällande vilka egenskaper lösningen bör ha för att anses som attraktiv i håltagningsindustrin. Utifrån den insamlade empirin genererades koncept med hjälp av brainstorming samt morfologi. Dessa utvärderades sedan med Husqvarna samt med hjälp av Pughs matris där kriterierna för sållningen togs utifrån fallstudiens resultat. Resultatet här blev en pådragsenhet som fäster i klingskyddets befintliga geometrier och tar upp damm och slurry vid den punkt i klingskyddet där den största delen av damm och slurry koncentreras vid sågning. Efter sållningen togs en prototyp fram för att kunna verifiera att damm och slurry kunde tas upp samt för att mäta dess effektivitet. Resultatet av prototyptestet var att konceptet kunde ta upp cirka 23% av slurryn samt markant reducera det synliga dammet. Konceptet kunde därmed anses uppfylla studiens syfte, speciellt gällande dammet då dess skadliga effekter på så sätt kan reduceras.Wall sawing in concrete generates a lot of dust. The dust is partly collected by the water that is applied as a coolant for the blade, which leads to a mixture called ”slurry”. The slurry as well as the dust needs to be removed after the sawing has been completed, which adds extra steps to the process for the user of the saw. The biggest issue here is the dust that is inhaled by the user, which can lead to diseases such as silicosis . This will probably lead to new regulations regarding how dust is managed, which has been the background of this thesis. The purpose of this study is therefore to evaluate how dust and slurry can be collected during wall sawing. The problem in wall sawing compared to other forms of processing of concrete is the difficulty in creating a seal towards the surface where the processing is being executed. It is for instance easier to create a sealed space around the are of processing during drilling where you can create a vacuum to collect the dust and slurry. An observation was conducted in order to give a basis for how the dust and slurry is acting during sawing. A case study was also executed to gather data regarding how the problem is solved today in the industry as well as to provide intel regarding important attributes that concepts must have in order to be considered attractive to the industry. Concepts were generated with the collected data as a base through brainstorming and morphology. The concepts were evaluated together with Husqvarna as well as with pugh’s matrix, where the set of criterias had been collected from the case study. The result was a slide on unit that locks to existing geometries and collects dust and slurry at the point where the biggest concentration is achieved during sawing. After the evaluation, a prototype was constructed in order to verify that dust and slurry could be collected and to measure the efficiency of the concept. The result of the test was that the prototype could collect approximately 23% of the slurry as well as significantly reduce the amount of visible dust. The concept could thereby fulfil the purpose of the study, especially regarding the decreasion of dust since the harmful effects of inhalation could be reduced.
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Степанчук, С. П. "Підвищення точності пиляння деревини на горизонтальних стрічкопилкових верстатах." Thesis, Видавництво СумДУ, 2010. http://essuir.sumdu.edu.ua/handle/123456789/13344.
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Застосування вдосконаленої конструкції напрямних і автоматичної системи динамічної оптимізації режиму різання на горизонтальних стрічкопилкових верстатах забезпечать зниження хвилястості пропилу, внаслідок чого підвищаться точність отриманих пиломатеріалів і продуктивність процесу пиляння, а також забезпечиться економія деревини, енергії та часу на подальших стадіях механічного оброблення. Крім того завдяки відсутності згину пилки в зонах контакту з напрямними збільшиться її довговічність, а завдяки зменшенню впливу людського фактора на точність пиляння знизяться вимоги до кваліфікації операторів стрічкопилкових верстатів.
При цитуванні документа, використовуйте посилання http://essuir.sumdu.edu.ua/handle/123456789/13344
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Johansson, Jimmy. "Mechanical processing for improved products made from Swedish hardwood." Doctoral thesis, Växjö : Växjö University Press, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:vxu:diva-2457.
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Ribeiro, Rogério Pinto. "Influência das características petrográficas de granitos no processo industrial de desdobramento de blocos." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/18/18132/tde-06032006-113052/.
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O desdobramento de blocos de granitos, em teares multilâminas, é uma das mais complexas operações da indústria da pedra. A qualidade das superfícies das chapas obtidas no processo de serragem (rugosidade) determina o tempo e os insumos gastos nas operações posteriores de polimento, implicando diretamente no custo final. Embora o Brasil seja um dos maiores produtores mundiais de granitos ornamentais (quatro milhões de 'M POT.2'/mês de placas), surpreendentemente, não se têm na literatura científica trabalhos que dão o devido destaque às propriedades intrínsecas dos granitos no processo de serragem. A presente pesquisa tem como objetivo principal correlacionar parâmetros petrográficos com as características físicas e mecânicas de granitos, dando ênfase ao estudo da influência da mineralogia e da anisotropia textural/estrutural, com vistas à melhor orientação desta etapa industrial. Foram escolhidos tipos de granito consagrados comercialmente e acompanhados os desdobramentos de blocos para medidas diretas da rugosidade das superfícies serradas com o auxílio de um equipamento especialmente construído para esta finalidade. Os resultados mostraram que os aspectos texturais (granulação, arranjo, imbricação, grau de microfissuramento) e de alteração dos minerais são os responsáveis pelas diferenças na rugosidade das chapas e na velocidade de processamentoThe sawing of granites blocks using multiblade gangsaws is one of the most complex operations in the stone processing industry. The slab surface quality (roughness) obtained after the sawing process determines the time and the inputs required in subsequent polishing operations and thus has a direct implication on the final product cost. Although Brazil is one of the largest world producers of ornamental granites (four million 'M POT.2'/month of slabs), it is surprising to note that there are very little or no scientific literature works available that address major aspects of the intrinsic properties of granites and their role during the sawing process. The present research has the major objective of correlating petrographic parameters with physical and mechanical characteristics of granites with a major emphasis on the role played by mineralogy and textural/structural anisotropy focusing mainly on how to obtain the best orientation during this industrial stage. The samples used are the most widely used granite of high commercial value in Brazil. The sawing process was monitored and subsequent direct measures of the roughness of the sawed surfaces carried out using an equipment specially built for this purpose. The results obtained show that textural (granulation, arrangement, imbrication, degree of microcracking) and alteration aspects of the minerals are responsible for the observed differences in slab roughness and processing speed
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Arrivabene, Lúcio Flávio. "Adição de resíduo da indústria de granito em escória de aciaria BOF visando sua utilização na produção de cimento." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/3/3133/tde-03072013-151931/.
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A produção de aço necessita de etapas e gera resíduo, dentre eles tem-se a escória de aciaria. No estado do Espírito Santo, Brasil, a mineração de granito é uma das principais atividades econômicas gerando o resíduo de serragem de granito. Nesta pesquisa, busca-se o reaproveitamento destes resíduos, de modo a minimizar possíveis problemas ambientais, apontar a viabilidade técnica do seu uso e reciclá-los por meio de utilização na produção de cimento. Alguns dos principais componentes das escórias de aciaria, tais como, o óxido de cálcio, óxido de magnésio e o ferro metálico sofrem transformações químicas em presença de umidade, que provocam expansão volumétrica da escória. Este fenômeno aliado a reatividade da escória tem dificultado sua utilização. Este trabalho é uma contribuição ao estudo do aproveitamento da escória de aciaria, que passa a ser chamada de ss (steel slag) e do resíduo da serragem de granito, que passa a ser chamado gsw (granite sawing waste), oriundo da extração de granito. Os resíduos estão disponíveis em quantidades nos pátios das siderúrgicas e nas áreas de mineração do granito, respectivamente. Para o reaproveitamento foi realizada a caracterização física, química e mineralógica dos resíduos. Diferentes dosagens de misturas foram produzidas com ss e gsw de forma a permitir avaliação das propriedades obtidas nestas misturas visando sua utilização na produção de cimento. Desenvolveu-se misturas nas quais busca-se a basicidade na escória de aciaria, compreendida entre 4 e 5, para valores próximos ao da escória de alto-forno, na faixa de 0,9 a 1,5 cuja utilização na produção de cimento já está normatizada desde 1991 (NBR 5735, ABNT 1991). Misturas com basicidade entre 0,9 a 4 foram pesquisadas e selecionou-se a mistura com basicidade 1,2 para ser utilizada na produção de cimento. Ao longo da pesquisa foi necessária a produção de 3(três) tipos de cimento até se equacionarem os problemas técnicos e operacionais que surgiram ao longo da mesma. Suas propriedades foram medidas e comparadas com as do cimento contendo escória de alto-forno. As análises dos resultados obtidos para o cimento produzido com a mistura são apresentadas e indicam o potencial de utilização dos resíduos como elementos de adição ao cimento apesar da heterogeneidade dos materiais.Steel making requires production stages and generates waste, such as steel slag. In the State of Espirito Santo, Brazil, granite mining is one of the main economic activities, wich generates granite sawing waste. This study aims at reusing these two types waste in order to minimize possible environmental problems; point out the technical feasibility of their use; and recycle them by using in cement. Some of the main components of steel slag, such as calcium oxide, oxides, and metallic iron undergo chemical transformations in the presence of humidity, wich cause slag volume expansion. This phenomenon, combined with slag reactivity, has made its use difficult. This study is a contribution to the study on reusing steel slag (ss) and granite sawing waste (gsw) deriving from granite mining. These types of waste are available in large amounts in the yards of steelmaking plants and granite mining areas, respectively. In order to reuse waste, physical, chemical and mineralogical characterizations were carried out. Different mix proportions were made with ss and gsw so as to allow the evaluation of the properties obtained from these mix designs, aiming at their use in cement production. The tests sought steel slag basicity between 4 and 5, for values close to those of blast-furnace slag ranging from 0.9 to 1.5, whose use in cement production has been standardized since 1991 ( NBR 5735, ABNT 1991). Mix designes with basicity between 0,9 and 4 were studied, and a mix with basicity 1.2 was chosen to be used in cement production. Throughout the investigation, 3 types of cement needed to be made until all the technical and operational problems arising were solved. Their properties were measured and compared to those of blast-furnace cement. The analyses of the achieved results for the cement made with that mix are presented and they show the potential use of these types of waste as admixture elements to cement, despite material heterogeneity.
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Santini, Alessandro. "Estudo do processo e dos parâmetros de corte no serramento da madeira por serra de fita." Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/88/88131/tde-14092016-121506/.
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O presente trabalho apresenta uma revisão bibliográfica sobre o processo de serramento por serra de fita, abordando fatores relativos ao desempenho de corte nas diversas operações deste processo. Na seqüência, apresentam-se os seguintes estudos específicos: características da madeira que exercem influência nas operações de serramento por serra de fita: o processo de serramento e; ferramentas de corte. A fim de se verificar os aspectos teóricos especificados na literatura para adequação do processo de serramento, efetuou-se um estudo de caso em uma serraria, usinando-se a espécie de madeira Pinus oocarpa em operação de desdobro com serra de fita vertical. Neste estudo, realizou-se a medição da potência consumida durante o corte com aquisição de dados em tempo real, a qual possibilitou calcular a potência de corte média.The present work shows a bibliographical review on band sawing, in respect to the factors related to cutting performance during the several operations of such process. Moreover, the following studies are presented: wood characteristics influencing the band sawing; sawing process itself; and cutting tools. In order to check the theorical aspects encountered in the literature to adequate the sawing process, a case study in a sawmill plant has been carried out. Pinus oocarpa wood species has been machied by unfolding using a vertical bandsaw. The consumed power during the cutting process was measured by a data acquisition system in real time, what allowed the calculation of the average cutting power.
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Franchin, Aline Costanzo. "Nitrificação de efluente de reator anaeróbio compartimentado em filtros percoladores com a utilização da serragem de couro do tipo wet blue como meio suporte." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-23012007-143309/.
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Com a utilização de filtros percoladores aeróbios, procurou-se promover a remoção de nitrogênio amoniacal do esgoto sanitário efluente de reator anaeróbio compartimentado, através do processo de nitrificação. O trabalho foi desenvolvido em duas fases; na primeira foi realizada a preparação da serragem de couro utilizando-se peneiramento e lavagens e a seguir iniciou-se a aplicação do esgoto sanitário em quatro filtros percoladores. Os filtros F1 e F2 foram operados com a mesma taxa de aplicação (1,91 'M POT.3'/'M POT.2'.dia) e diferentes meios suportes, sendo brita e serragem de couro do tipo wet blue respectivamente. Os filtros F3 e F4 foram preenchidos com serragem de couro e operaram com taxa de aplicação hidráulica de 4,00 e 6,00 'M POT.3'/'M POT.2'.dia . O filtro F3 apresentou melhores eficiências de remoção para todos os parâmetros, com eficiência média de remoção de NTK, 'N'-'NH IND.3' e DQO de 71%; sendo que a partir do sexagésimo quarto dia, esse filtro passou a apresentar 100% de remoção de NTK e 'N'-'NH IND.3'. Os filtros F1 e F2 podem ter tido problemas com a aeração, já que foram operados com menores taxas de aplicação hidráulica e deveriam apresentar melhores resultados. O filtro F4 apresentou baixas eficiências de remoção, provavelmente devido a maior taxa de aplicação hidráulica.The aim of the work is to promote the ammoniacal nitrogen removal from anaerobic baffed reactor effluent using aerobic trickling filters, through the nitrification process. The research was developed in two phases; firstly the leather sawing was prepared through sieving and washing, later the domestic sewage was applied into four tricking filters. The F1 and F2 filters were operated with the same hydraulic loading (1,91 'M POT.3'/'M POT.2'.day) and different filter packing. For the F1 filter was used rock and for the F2 wet blue leather sawing. The F3 and F4 filters were filled with leather sawing and operated in a hydraulic loading of 4,00 and 6,00 'M POT.3'/'M POT.2'.day respectively. The F3 filter presented better removal efficiencies for all the parameters, with 70% of average removal efficiency of KTN (Kjeldahl Total Nitrogen), 'NH IND.3'-'N' (ammoniacal nitrogen) and COD (Chemical Oxygen Demand). From the 49th day on, this filter presented 100% of removal efficiency of KTN and 'NH IND.3'-'N'. The F1 and F2 filter were supposed to present better results due to the lower hydraulic loading, but it did not happen, probably because the aeration was not enough. The F4 filter presented low removal efficiency, possibly due to the higher hydraulic loading.
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Mello, Tiago Chaves. "Influência dos parâmetros do processo de serramento no corte de capacitores de filme metalizado ultrafino." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/127878.
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Visando determinar os valores ótimos para o processo de serramento de anéis bobinados de filme metalizado ultrafino de alumínio com dielétrico de poliéster a partir das condições atuais do processo de fabricação de capacitores pela empresa Epcos do Brasil, realizou-se a avaliação de diferentes tipos de serras circulares variando-se a velocidade de rotação (n) e o tempo de corte (tc). Desenvolvido projeto de experimento desses três fatores a fim de obter o resultado das interações entre eles quanto à resistência de isolamento (Riso) das peças cortadas. A serra de 160 dentes de metal-duro com revestimento de filme de carbono tipo diamante (DLC) apresentou os melhores resultados quanto à “Riso” acima de 0,378 G e quanto ao número de peças com valor abaixo deste. Constatou-se que “n” não influencia significativamente para a distribuição de “Riso”; porém, gera menos peças abaixo do especificado. Já “tc” não influencia significativamente o processo. Quanto ao tipo de dente, o perfil reto obteve melhor resultado para lâminas de serra com 80 dentes e perfil curvo para lâminas com 160 dentes. Já a espessura da lâmina não influenciou de forma expressiva o processo. A lâmina de aço-rápido apresentou adesão de alumínio na lateral do corpo da serra e, consequentemente, adesão de material na superfície de corte. As lâminas de metal-duro sem revestimento apresentaram falhas no filme metalizado por causa do atrito gerado entre a superfície de corte e a lateral da lâmina; esse inconveniente é eliminado quando ela é revestida com filme DLC apresentando melhorias quanto à “Riso” das peças para “n” menores. Também houve adesão de alumínio na parte inferior do dente devido a uma delaminação da camada de filme DLC.In order to determine the optimal values for the sawing process of wound rings of metalized ultra-thin film with dielectric of polyester from current conditions of capacitor manufacturing process by Epcos company in Brazil, it was performed the evaluation of different types of circular saws varying the rotational speed (n) and the cutting time (tc). Developed experiment design methodology for these three factors in order to get the result of the interactions between them regarding to the insulation resistance (Riso) of cut parts. Through the analysis of the main effects, the cemented carbide saw with 160 teeth and diamond-like carbon (DLC) film coating showed the best results in terms of "Riso" above 0,378 G and regarding to the number of parts with value below the specified. It was found that "n" does not influence significantly the distribution of "Riso"; however, generates fewer parts below the specified. Now "tc" does not significantly influence the process. Regarding the tooth type, straight profile obtained better results for saw blades with 80 teeth and curved profile for blades with 160 teeth. However the thickness of the blade did not influence significantly the process. The high speed steel blade presented adhesion of aluminum on the side of the saw body and, consequently, adhesion of material on the cutting surface. The cemented carbide blades uncoated presented failures on metalized film because of the friction generated between the cutting surface and the side of the blade; this drawback is eliminated when it is coated with DLC film presenting improvements to the parts "Riso" for lower "n". There was also aluminum adhesion on the bottom of the tooth due to a delamination of the DLC film layer.
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Breinig, Lorenz [Verfasser], and Gero [Akademischer Betreuer] Becker. "CT log scanning for sawing optimization with regard to the aesthetic quality of wood = CT-Aufnahmen von Rundholz für die Einschnittoptimierung im Hinblick auf die ästhetische Qualität von Holz." Freiburg : Universität, 2015. http://d-nb.info/1115861689/34.
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Metelková, Jitka. "Řezání litých superlitin." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-256567.
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This work deals with the issue of defects generation during the separation of the castings from a nickel-based superalloy, Inconel 738LC. The technology of investment casting is presented, followed by a description of metallurgy of superalloys, their physical and mechanical properties, as well as their technical applications. The machinability of superalloys and method of castings separation were also described as well as some of the casting defects that were reported to have impact on the generation of the defects after cutting. In the experimental part, the material microstructure and casting defects were analyzed. The experimental machining part consisted first of a comparative study of the friction sawing and plasma arc cutting technology at the standard operating conditions actually used in production. Second, an optimization study for the friction sawing was carried out, with a special focus on the suitability of an alternative cutoff wheel for the chosen application. Application of this wheel allows reducing the security distance between the cut and the part, thus reducing the production cost of the part.
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Weber, Bernd. "Untersuchung der Material begrenzenden Einflüsse beim Multidrahtsägen von Silicium unter Verwendung gerader und strukturierter Drähte." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2015. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-173276.
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In der vorliegenden Arbeit wurden experimentelle Untersuchungen zu Material begrenzenden Einflüssen beim Multidrahtsägen von Silicium unter Verwendung gerader und strukturierter Drähte durchgeführt. Ziel dieser Arbeit war es, den Einfluss von dünnen und strukturierten Drähten auf den Drahtsägeprozess von Silicium und die erzeugten Waferqualitäten zu untersuchen. Zusätzlich galt es, Grenzen und Potentiale für den Einsatz dieser Drähte im Sägeprozess aufzuzeigen und ein Modell zu entwickeln, das den Materialabtrag in Silicium für strukturierte Drähte beschreibt. Die in dieser Arbeit verfolgten Lösungsansätze beinhalten im ersten Teil der Arbeit die Durchführung von Sägeexperimenten mit einer Eindrahtsäge. Es wurden dünne Drähte mit Durchmesser ≤ 100 µm und zwei unterschiedliche Siliciumcarbid (SiC) Korngrößenverteilungen untersucht. Zusätzlich wurden die Normalkräfte in Vorschubrichtung variiert. Im zweiten Teil der Arbeit werden Sägeexperimente mit einer Multidrahtsäge vorgestellt. Es wurden zwei unterschiedlich strukturierte Drähte mit variierten Drahtgeschwindigkeiten und Vorschüben im Vergleich zu geradem Draht untersucht. Der industrielle Einsatz dünner Drähte im Sägeprozess zur Reduzierung des Sägeverschnitts ist derzeit auf Durchmesser von 100 µm begrenzt. Die getesteten Drähte mit geringerem Durchmesser sind nicht wirtschaftlich einsetzbar, da sie zu geringe Standzeiten aufweisen und zu einer Slurryverarmung beitragen können. Es konnte eine Slurryverarmung des Schnittspalts in Silicium beobachtet werden, die um mehrere Zentimeter in den Schnittspalt ragt und dadurch den Drahtsägeprozess negativ beeinflusst, indem Sägeriefen entstehen. Die Verschleißuntersuchungen von Sägedrähten zeigen, dass eine lineare Abnahme der Drahtdurchmesserreduzierung in Abhängigkeit der akkumulierten Eingriffslänge in Silicium auftritt. Der Prozess der Durchmesserreduzierung wird maßgeblich durch die aufgebrachte Normalkraft, welche durch die Zugfestigkeit und Härte des Drahts beeinflusst wird, die Drahtgeschwindigkeit und die verwendete Korngrößenverteilung bestimmt. Es konnte durch Sägeversuche mit Drähten unterschiedlicher Hersteller gezeigt werden, dass das beobachtete Verschleißverhalten nicht einem Drahthersteller zuordenbar ist, sondern eine globalere Gültigkeit besitzt. Der industrielle Einsatz strukturierter Drähte wirkt sich positiv auf den Sägeprozess aus. Es konnten signifikant höhere Vorschübe bei ähnlichen Kräften im Vergleich zu geraden Drähten erreicht werden. Für einen Vorschub von 0,6 mm/min sind die Kraftwerte für strukturierten Draht A im Vergleich zu geradem Draht um 40% reduziert, für Draht B um 16%. Durch die Drahtstruktur wird ein größeres Slurryvolumen durch den Schnittspalt befördert, was zu einem homogeneren Materialabtrag entlang des Schnittspalts führt. Die erhöhten Vorschübe konnten sowohl für mono- wie auch für multikristallines Siliciummaterial erreicht werden. Zusätzlich wurden homogenere Waferdicken durch den Einsatz strukturierter Drähte beim Sägeprozess erzeugt. Auf Basis der Ergebnisse für strukturierte Drähte wurde ein theoretisches Modell für den Materialabtrag entwickelt, welches die in dieser Arbeit durchgeführten Experimente gut beschreibtIn the present work experimental analyses were carried out to investigate the material limiting influences in the multi wire sawing process of silicon while using thin and structured wires. The purpose of the work was to investigate influences on the wire sawing process and the resulting wafer qualities caused by thin and structured wires. Additionally, the purpose was to define the limits and potentials of thin and structured wires in industrial wire sawing processes and to develop a model which describes the material removal in silicon for structured wires. Experiments with two different SiC particle size distributions in combination with wire diameters of ≤ 100 µm and varying normal forces in feed direction were carried out in the first part of this work with a single wire saw. Experiments with two differently structured wires and variation of the wire speed and feed rate are shown in the second part using a multi wire saw. The actual limit for industrial sawing applications to reduce kerf loss is reached for 100 µm thin wire diameters. The tested lower wire diameters are uneconomical due to shorter durability and to aggravate slurry depletion effects. Such a depletion effect of several centimeters length which is detrimental for the wire sawing process was observed at the end of a sawing channel. The results of the experiments showed that the steel wire diameter is reduced linearly with the accumulated sawn length of silicon. The material removal process of the steel wire is significantly influenced by the normal force in feed direction and the hardness of the wire. The experiments with wires of different suppliers showed no difference in the material removal process. Therefore the abrasive wear of wires has a more global validation. The results of the experiments using differently structured wires showed that significantly lower forces in feed direction occur for a given feed rate in comparison to straight wires. The forces are reduced up to 40% for structured wire A and up to 16% for wire B for a feed rate of 0,6 mm/min. A higher slurry volume is transported due to the structure of the wire which enables a more homogeneous material removal process along the cutting channel. Higher feed rates were reached for mono- and multi crystalline silicon material. Additionally, more homogeneous wafer thicknesses were cut using structured wires
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Souidi, Ramzi. "Etudes des propriétés physiques et chimiques de la surface des substrats de Silicium après découpe dans les applications aux cellules solaires photovoltaïques." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAY017/document.
Full textAbstract:
Pour l’industrie photovoltaïque (PV) l’optimisation de la découpe de lingot de silicium en tranches représente un enjeu à la fois économique et scientifique. Enjeu économique en ce qu’il est important de réduire la perte de matière induite par la découpe. Enjeu scientifique en ce qu’il est nécessaire de comprendre l’impact du sciage sur la qualité du silicium au voisinage de la surface. Ce travail de thèse de doctorat a pour objectif de caractériser la nature et l’extension de l’endommagement généré par une technique innovante de découpe réalisée à l’aide de fils diamantés. Un objectif majeur est d’évaluer l’épaisseur de la couche de silicium perturbée (appelée SSD). Afin de caractériser la SSD, des analyses physico-chimiques en fonction de la profondeur ont été réalisées d’une part, sur des échantillons bruts de découpe en surface, en coupes biaises ou transverses et d’autre part, par enlèvement progressif de matière par des attaques chimiques en solutions diluées. Des protocoles de préparation d’échantillons ainsi que de nombreuses techniques de caractérisation ont été utilisées. En particulier des techniques de microscopie (optique, confocale, électronique MEB et TEM), de spectroscopie de photoélectrons (XPS), de diffraction de rayons X (DRX), de spectroscopie Raman ainsi que des essais de résistances mécaniques aboutissent à une caractérisation multi-échelle des tranches et de coupons. Un polissage en coupes biaises avec un angle faible permet d’étendre la zone d’observation des défauts en profondeur et d’en faire une analyse statistique. De plus, des méthodes de mesure de durée de vie des porteurs minoritaires sont exploitées pour évaluer les processus de recombinaison sur la couche perturbée. Le temps de vie a été obtenu via la mesure de la décroissance de photoconductivité (PCD) sur des surfaces passivées par différents matériaux (SiNx :H, Al2O3) et procédés de dépôts (PECVD, ALD). D’abord, la caractérisation des échantillons bruts de découpe indique que les défauts majeurs de la SSD sont des fissures générées par la découpe et qui se propagent en subsurface. Ces fissures se distribuent sur des profondeurs variables et hétérogènes selon les conditions de découpe. Ensuite, les résultats de la méthode par enlèvement contrôlé montrent, d’une part, un effet de la SSD dans les processus de recombinaison. La précision d’évaluation de cet effet est conditionnée par des passivations de surface optimisées et des mesures fiables du temps de vie. D’autre part, ils montrent une interaction de l’attaque chimique avec les fissures. Ce dernier point est déterminant dans l’évaluation de l’épaisseur de la SSD globale pouvant impacter les performances des cellules solairesFor photovoltaic industry (PV), the optimization of cutting silicon ingot into wafers represents both an economic and a scientific issue. Economic challenge in that it is important to reduce the loss of material induced by cutting. Scientific issue in that it is necessary to understand the impact of sawing on the quality of silicon near the surface. This PhD research work aims to characterize the nature and extent of the damage generated by an innovative cutting technique using diamond wires. A major objective is to evaluate the thickness of the subsurface damage layer (called SSD). In order to characterize the SSD, physical and chemical investigations as a function of depth were performed on either as-cut surface, bevel or transverse sectioned samples or by removal of material by sequential etching in diluted solutions. Sample preparation protocols as well as many characterization techniques were used. In particular microscopy techniques (optical, confocal, electronic SEM and TEM), photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectroscopy and mechanical strength tests allow multiscale characterization of wafers and coupons. A low bevel angle polishing lets to extend the observation zone of deep defects and to make a statistical analysis. Furthermore, methods from measuring the minority carrier lifetime are used to evaluate the recombination processes on the disturbed layer. The lifetime was obtained by photoconductivity decay (PCD) measurements on SiNx: H and Al2O3 passivated surfaces obtained from PECVD and ALD deposition processes respectively. First, characterizing samples from as-cut wafers indicates that the major defects of the SSD are cracks generated by cutting and propagated into the subsurface. These cracks are distributed over varying and heterogeneous depths depending on the sawing conditions. Second, the results of the sequential removal method show, on the one hand, an effect of the SSD in recombination processes. The evaluation accuracy of this effect is conditioned by optimized surface passivation and reliable measurements of lifetime. On the other hand, an interaction of chemical attack with cracks is shown. This is crucial in the evaluation of the absolute thickness of SSD layer that may impact the solar cells performance
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Juřicová, Vendula. "Konstrukce pily na profily hliníkového konstrukčního systému." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-254309.
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This diploma thesies is focused on design of a sawing machine for profiles of the aluminium profile system. In the beginning the basic types of sawing maschines are described, followed by the analysis of alternative solutions, selecting the best option, design of the final solution and evaluation. The resulting solution should be ergonomically acceptable, safe, affordable and efficient.
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Suassuna, Rita de Cascia Avelino. "Utilização de serragem de couro do tipo wet blue como meio suporte de filtros percoladores para pós-tratamento de esgoto sanitário tratado em reator anaeróbio compartimentado." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-12092016-100129/.
Full textAbstract:
Nesta tese foi estudada a utilização da serragem de couro do tipo wet blue como meio suporte de filtros percoladores no pós-tratamento de esgoto sanitário. O desenvolvimento deu-se em três fases: na primeira fase foram realizadas a classificação e caracterização da serragem, bem como a sua preparação através de peneiramento, lavagens e secagem. Foram realizados dois tipos de lavagens: uma em batelada com solução alcalina de pH em torno de 9,0 e outra contínua com água corrente com pH em torno de 7,0. Na segunda fase foram utilizados quatro filtros percoladores com volume aproximado de 10 litros; dois foram preenchidos com serragem de couro bruta peneirada e os outros dois com serragem de couro peneirada, lavada e seca ao ar livre. Esses filtros operaram em série com quatro filtros de volume aproximado de 30 litros, preenchidos da mesma forma. Os quatro primeiros filtros receberam o efluente de um reator anaeróbio compartimentado e os demais receberam os efluentes dos primeiros. A terceira fase consistiu do uso apenas dos filtros percoladores de maiores volumes, os quais operaram aerados e com o afluente alcalinizado. Os conjuntos de filtros que operaram em série na segunda fase apresentaram eficiências de remoção de coliformes totais e fecais que variaram em torno de 94 e 92%, respectivamente. A eficiência de remoção de DBO5 total foi cerca de 80%. Na terceira fase, os filtros apresentaram eficiências de remoção de coliformes totais e fecais de cerca de 98 e 99%, respectivamente. Com relação à eficiência de remoção de DBO5, o valor encontrado foi de aproximadamente 80%. Nesta terceira fase foram encontradas excelentes reduções de NTK e de nitrogênio amoniacal com eficiências médias de remoção, para os dois parâmetros, de 83% antes da alcalinização e de 100% após a alcalinização.This thesis studied the use of leather sawing (wet blue type) as packed bed of trickling filters in the wastewater post-treatment. The thesis was divided into three stages: as first stage the classification and characterization of the leather sawings were accomplished, as well as its conditioning through sieving, washing and drying. Two washing techniques were accomplished: a batch one with alkaline solution of pH around 9,0 and a continuous one with water of pH around 7,0. In the second stage four trickling filters were used with an approximated volume of 10 L; two were filled with sifted raw leather sawing and the two others with sifted, washed and open-air dryed leather sawing. Those filters operated in series with four other filters with an approximated volume of 30 L, filled in the same way. The 10 L filters received the efluent of an anaerobic baffled reactor and the others received the efluents of the first ones. The third stage consisted on the 30 L trickling filters alone, which were aerated and feeded with alkalinized influent. The group of filters that operated in series in the second stage presented total and fecal coliform removal efficiencies that varied around 94 and 92%, respectively. The efficiency of total BOD5 removal was around 80%. In the third stage filters presented total and fecal coliformes removal efficiencies around 98 and 99%, respectively. About BOD5 removal efficiency, it was found a value of approximately 80%. In this stage it was achieved excellent KTN and ammoniacal nitrogen removals with average removal efficiencies of 83% before alkalinization and 100% after alkalinization.
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Moreira, Sérgio Luis Siebra. "Pós-tratamento de esgoto sanitário tratado em reator anaeróbio com o uso de serragem de couro curtido tipo \"wet blue\" como meio suporte de filtros percoladores." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-31102016-150236/.
Full textAbstract:
A proposta desta pesquisa foi fazer um teste preliminar da hipótese que serragem de couro tipo wet blue seria adequado meio suporte para filtros percoladores destinados ao pós-tratamento de esgoto sanitário. Para verificar a possível ação biológica e a eficiência desse material, neste estudo foram realizadas: avaliação do desempenho dos filtros percoladores no pós-tratamento de esgoto sanitário, utilizando como meio suporte serragem desse tipo, gerada em curtumes - essa é uma forma de resolver o problema do pós-tratamento de esgoto sanitário e de atenuar os efeitos tóxicos da serragem de couro curtido tipo wet blue; avaliação e monitoramento de parâmetros indicadores que permitam controle simples sobre o processo - pode-se citar entre eles: DBO5, DQO, NTK e nitrogênio amoniacal; e verificar a eficiência dos filtros percoladores na redução da quantidade de coliformes fecais presentes em esgoto sanitário. O sistema apresentou excelente eficiência principalmente na remoção de DQOtotal de 60% (σ= ±30%) e DQOdissolvida 60% (σ= ±13%). De início a remoção de coliformes foi total - o que pode evidenciar o efeito tóxico da serragem, devido à grande presença de cromo na serragem; no entanto, exames posteriores detectaram a existência de coliformes nos efluentes de todos os filtros levantando uma dúvida a respeito da toxicidade da serragem. Ainda que se conheçam inúmeras formas de tratamento de efluentes líquidos, a proposta de usar serragem de couro - que é gerada em curtumes em grande quantidade - como meio suporte em filtros percoladores pode significar um passo para que se encontre solução conjunta tanto para a serragem - resíduo indesejável - como para o pós-tratamento de esgoto sanitário.The research proposal was to perform a preliminar test upon the hypothesis that type wet blue leather sawing would be adequated as a means of percolator filter support destinated to the sanitary sewage post treatment. To investigate the possible biological action and that of the material efficiency some actions were taken: performance evaluation of the percolators filters in the sanitary sewage post treatment, using as a support means the sawing of that type, generated in a tanning plant - this is one way of solving the problem of sanitary sewage post treatment, as well as, to attenuate the toxic effects of the type wet blue leather sawing; the evaluation and monitoring of indicator parameters that turn to a possible simple control on the process - such as BOD5, COD, NTK and amoniacal nitrogen; to investigate the percolator filter efficiency in the reduction of fecal coliform population that are present in the sanitary sewage. The system presented an excellent efficiency, mainly in the removal of CODtotal 60% (σ = ±30%) and CODdissolved 60% (σ = ±13%). In the beginning the coliform removal was total - what could have been caused by the sawing toxic effect, due to substancial amounts of chromium in the sawing; however, later analysis detected the existence of coliforms in the effluents of all filters originating a questionable subject about the sawing toxicity. Despite the fact that there are a great number of liquid effluenttreatments, the proposal of the use of leather sawing - generated in large amounts in tanning plants - as a support means for percolator filters, might be a step to find out a conjunction solution for the sawing - undesirable residue - as well as for the sanitary sewage post treatment.
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Shepley, Brian Patrick. "Simulating Optimal Part Yield from No. 3A Common Lumber." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/36226.
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The percentage of low-grade material composing the annual hardwood lumber production in the U.S. is on the rise. As a result, finding markets for low-grade and low-value lumber has been identified as a top priority by researchers and industry associations. Computer simulation has been used by the manufacturing industry for several decades as a decision support tool. Simulation programs are commonly used and relied on by researchers and the industry alike to conduct research on various aspects of the rough mill from processing to recovery efficiency. This research used the ROMI-RIP and ROMI-CROSS simulation programs to determine specific conditions that led to optimal part yield when processing No. 3A Common, 4/4-thickness, kiln-dried, red oak lumber in rip-first and crosscut-first operations. Results of the simulations indicated that cutting bills with narrow part widths and short part lengths are conducive to obtaining optimal part yield while processing No. 3A Common lumber. Furthermore, it was found that as the percent of No. 3A Common lumber in a grade mix increases, part yields and sawing efficiencies decrease. The results also indicated that higher part yields will be obtained when processing short-length No. 3A Common lumber between 6 and 8 feet in length.Master of Science
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Sandberg, Dick. "Value Activation with vertical annual rings - material, production, products." Doctoral thesis, Linnéuniversitetet, Institutionen för teknik, TEK, 1998. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-19082.
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Chung, Hsiao-Yen, and 鍾効諺. "The Study of Sawing Performance Affected by Sawing Vibration on CNC Band Sawing Center." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/15222661703815104178.
Full textAbstract:
碩士國立虎尾科技大學
機械與機電工程研究所
102
Band sawing machine is the most efficient cutter for large metal cutting , its advantages are less material loss, large cutting range, low cost..., the range of it’s sawing capability is very wide, it can be applied for timber, stone, polymer materials, metals and non-ferrous metal materials, and for each different material for cutting there is a corresponding design of the tooth saw blade and blade material to improve cutting performance and life of the saw blade. With the advancement of composite materials and alloys technology, it greatly improves the hardness, the traditional high-speed hacksaw is no longer enough for todays high hardness cutting material , therefore has started using tungsten hacksaw to achieve high efficiency and improve productivity.Band saw having the longest of route of all blades, has more limit to it’s anchor(support point), the structure is prone to vibration, which leads to a great impact for tungsten hacksaw blade, affecting the life and cutting the cost of the hacksaw.The main purpose of this study focuses on analyzing all of the causes lead the source of the vibration, and analyze the linear relationships between the band saws natural frequency and the cutter condition, to find the damping method and the best cutter condition. Targeting the three materials S45C, SUS304, SKD61 put under a long term cutting condition to accurately measure the band saw cutting life. The method consists of of accelerating and compliance with the measurement system to capture the vibration data and the using of the fast Fourier transform to transform the data into frequency spectrogram to carry out the analyzing. Using the finding of the band saw vibrating characteristics and impact of excitation source, therefore understand the smallest band saw vibration and it’s surface cutter condition.
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Chung, Hsiao-Yen, and 鍾?諺. "The Study of Sawing Performance Affected by Sawing Vibration on CNC Band Sawing Center." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/je8h36.
Full textAbstract:
碩士國立虎尾科技大學
機械與機電工程研究所
102
Band sawing machine is the most efficient cutter for large metal cutting , its advantages are less material loss, large cutting range, low cost..., the range of it’s sawing capability is very wide, it can be applied for timber, stone, polymer materials, metals and non-ferrous metal materials, and for each different material for cutting there is a corresponding design of the tooth saw blade and blade material to improve cutting performance and life of the saw blade. With the advancement of composite materials and alloys technology, it greatly improves the hardness, the traditional high-speed hacksaw is no longer enough for todays high hardness cutting material , therefore has started using tungsten hacksaw to achieve high efficiency and improve productivity.Band saw having the longest of route of all blades, has more limit to it’s anchor(support point), the structure is prone to vibration, which leads to a great impact for tungsten hacksaw blade, affecting the life and cutting the cost of the hacksaw.The main purpose of this study focuses on analyzing all of the causes lead the source of the vibration, and analyze the linear relationships between the band saws natural frequency and the cutter condition, to find the damping method and the best cutter condition. Targeting the three materials S45C, SUS304, SKD61 put under a long term cutting condition to accurately measure the band saw cutting life. The method consists of of accelerating and compliance with the measurement system to capture the vibration data and the using of the fast Fourier transform to transform the data into frequency spectrogram to carry out the analyzing. Using the finding of the band saw vibrating characteristics and impact of excitation source, therefore understand the smallest band saw vibration and it’s surface cutter condition.
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Zhang, Jian-Bin, and 張建彬. "Study of Sawing Performance of High-speed Band Sawing Machine on H-beam." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/h3njsq.
Full textAbstract:
碩士國立虎尾科技大學
機械與機電工程研究所
103
Band sawing machine is a mechanical cutting technology, it has developed nearly 50 years. Application in many places, ex: The construction industry, Machinery and equipment manufacturing, Automotive industry, Aerospace specialty materials, etc. Band sawing machine is the most efficient cutter for large metal cutting, its advantages are less material loss, large cutting range, low cost, low material qualitative. In this study, we measurements with cutting vibration, motor current and H-beam strain. Discussion the effects of different bow saws for cutting angle of inclination. The saw arm is fixing member closest point of cutting. Use accelerometer adhesive on both sides saw arm axial and radial to measurement cutting vibration. Understanding the vibration behavior of the cutting process. In addition, Band saw contact length big change with cutting H-beam. So cutting vibration bigger. When band saw cutting, it will be clip because of H-beam stress effect. So the strain adhesive on materials. Establish immediate strain measurement system to measure strain. The main driving force of the motor to drive the saw band. Needs more current to drive the motor driven band saw continued cutting when the big resistance. Establishing motor measurement system to monitor motor current changes. Adjustments cutting rate and band saw speed to study correlation between vibration, motor current and H-beam strain. And use ANSYS Workbench set up cutting force model. Observe the stress distribution and the band saw tension changes and ratio on actual results.
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Jing-WenLu and 盧靖文. "Applying AVM for Wafer Sawing Processes." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/wp2hmz.
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Liang, Jiun-Shuo, and 梁峻碩. "Study on Wire Sawing of Solar Wafers." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/35860932564927713473.
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碩士國立臺灣科技大學
機械工程系
96
Multi-wire sawing technology has been widely applied on fabricating the substrates of solar cells. This research is to develop a wire sawing model (WSM) to predict the material removal rate (MRR) of slicing substrate of solar cell and also to invesigate the significant process parameters of wire sawing. The micro Vickers hardness test is used to estimate the indentation fracture of brittle material for estimating the material removal volume by each indentation. Calculation of the number of engaged grits in working area can also be obtained by particle size analyzer to measure the particle size distribution (PSD) before and after wire sawing. Results show that the number of engaged tip of abrasive is the main factor of material removal rate. So the simulation of MRR use this factor collocated with other factors for exploring other effects. Results of simulation show that the MRR is in direct proportion with the wire speed, Young’s modulus of workpiece and the number of engaged grits for each instant sawing in working area and in inverse proportion with hardness and fracture toughness of workpiece. Further research is to predict the MRR of related brittle materials. The method of estimation of the number of engaged grits in working area can also be used in other abrasive machining system with recirculated slurry system.
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Wu, Kuo-Hwa, and 吳國華. "Implementation of Numerical Controlled Sliding Table Sawing Machine." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/31924906734116181939.
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碩士國立彰化師範大學
電機工程學系
96
ABSTRACT Due to the opening-up of China’s economy, Taiwan’s woodworking machinery industry has encountered a severe challenge by China’s low price strategy since 2003. The export volume of Taiwan’s low-technical-threshold DIY woodworking machinery have dropped gradually from 3,179,000 sets in 2004 to 2,052,000 sets in 2006. In the meantime, the import volume have increased from 9,948 sets in 2005 to 18,801sets in 2006. According to the statistics of Taiwan’s Ministry of Economic Affairs, the averaged unit price for the exporting woodworking machinery is NT$ 9,992 in contrast to NT$ 17,724 for the importing ones. Making a thorough inquiry into the problem, we concluded that the results were arose from the deficiency in upgrading the woodworking machinery to higher add-on value NC equipments. In this thesis, we chose the most common woodworking machine, sliding table saw, as our main topic. In the study, we reformed a original manual-operation sliding table saw to automatic controlled one by introducing several new key components in mechanism and developed a new controller which adopted the SM5964C4 as its processor to achieve the numerical positioning control. Following is a brief introduction to the system. A running mechanism consists of the retard gear and ball screw driven by brush DC motors to adjust the saw rotation angle and height position. The position and limits of all the axes are determined by the encoder and the feedback of the detection of proximity sensors. Meanwhile, we utilize the PWM ( Pulse Width Modulation ) method for the speed control of brush DC motors. By coordinating the proportional enlarge output mechanism and PWM speed control system, we accomplish the design of a low-cost NC controller which met the specification of ±0.01mm in positioning accuracy. With the development of the kernel of low cost NC controller, we can upgrade the add-on value and improve the accuracy of the woodworking machinery. Furthermore, we can promote the whole value of woodworking machinery and elongate the vitality and global competitiveness of Taiwan’s woodworking machinery industry through the raise of the exporting value. Keywords: Sliding Table Sawing 、Microchip
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Wen, Fu-Lin, and 溫福麟. "Metal removal for recycling of silicon sawing waste." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/2f6u33.
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碩士國立臺北科技大學
資源工程研究所
100
Silicon ingot cut wafer produce abundant silicon sawing waste during the sawing process. If it can be recycled, it can reach the purpose of environmental protection and the reduction of cost. In order to promote the post application value of silicon and silicon carbide, the removal of metal impurities is essential when recycling silicon sawing waste. The experimental results show that silicon and silicon carbide can be separated by using centrifugation. When recycling of silicon sawing waste was performed by using the centrifugation in a magnetic field, the iron can be removed from silicon powders by the ratio of waste to solvent is 3/7. In addition, this study show that H2SO4 aqueous solution could react with the waste rapidly and remove most of metal. The residual iron in the silicon powder could reach 28.83ppm. If the sawing waste was pretreated by use of scrubber, the residual iron could reach 25.99ppm.The analysis of chemical kinetics show that the reaction order for metal oxidation in sulfuric acid is higher than that in hydrochloric acid, citric acid or nitric acid, meaning that the reaction in sulfuric acid is more sensitive to the concentration of hydrogen ion. The reaction of citric acid to metal oxidation has the lowest activation energy. The reaction of nitric acid to metal oxidation has the highest activation energy. The research shows that a ultrasonic cleaner removed most iron in a short period of time. However, in a long period of time, the effectiveness of removing iron by using a stirrer is better than using a shaker or an ultrasonic cleaner. In this research, we separated silicon and silicon carbide and removed iron impurities from the cutting waste successfully by using the centrifugation in a magnetic field. By acid treatment, we can reduce iron impurities to less than 100ppm. Because the concentration of acid is low, it can prevent damage to the environment, and it can realize the target of simplifying the process and reducing cost.
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Kuo, Bing-Lin, and 郭柄麟. "Slurry Analysis for Wire Sawing of Silicon Wafers." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/18178173473678711989.
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碩士國立臺灣科技大學
機械工程系
97
Multi-wire sawing process with slurry has been popularly adopted for wafer slicing of silicon substrates for solar cells. This research is to develop a slurry durable index（SDI）to define the slurry life time, and add slurry viscosity and temperature into the wire sawing model（WSM）to improve the simulation accuracy of material removal rate（MRR）. There have been set two sawing parameters of free abrasive sawing process to cut the multi-crystalline silicon ingots. Investigating the silicon substrates （roughness, total thickness variation and subsurface damage）, the measured results are to define the affects of grits to wafers’ quality and the slurry life time after sawing. Calculation of SDI can be obtained by particle size analyzer to measure the particle size distribution（PSD）before and after wire sawing. The viscosimeter is used to measure the slurry viscosity with temperature and estimated the working grits number by immersing the wire into slurry at different temperature to improve the MRR. The result of SDI is 3.581 and proportion with particle size deviation of slurry. The slurry weight and ratio of wafer thickness to roller groove pitch is in inverse proportion. Results of this paper can be used to estimate the slurry life time and for maintaining the TTV under the desired specifications of silicon substrates for cost efficiency.
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Wu, Kuo-Jung, and 吳國榮. "Using Designing of Experiments to Determine the Optimal Sawing Parameter Setting for Assembly Die Sawing -A Case Study of X Company." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/5sk3tq.
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碩士國立交通大學
管理學院工業工程與管理學程
107
The importance of the scribe line for wafer sawing is indispensable, it can also be regarded as the most key process that directly affecting wafer yield. By controlling the parameters of scribe line, it can improve the problems of die crack and yield loss. Moreover, it is quite helpful of company to strengthen the competitiveness. This research topic is to solve the topside as well as backside crack issue when X company narrower the scribe line from 80μm to 60μm that result in poor competitiveness and the endless complaints from customers. In this study, the three important independent variables: 1st spindle speed, 2nd spindle speed, feed speed are analyzed by Cause & Effect Analysis, then using design of experiments combined with central composite design to define the proper parameters. The combination of three independent variables successfully avoid die crack, make output increasing, and improve yield.
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Jin, Tzeng Chau, and 曾潮金. "Constructing of the Sawing Model for an Industrial Bandsaw." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/81267364301838650691.
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碩士國立清華大學
動力機械學系
83
The principal purpose of this paper is to develop a sawing model which is designated to study the influential parameters, such as blade velocity, feed force, workpiece length and blade pitch, on the cutting rate. In order to realize the effects of chip clogged and blade deflection on the cutting rate, an expe- riment was performed in this research. The feasibility of de- signing a special bandsaw mechanism to obtain the highest cutting rate was evaluated. Theoretically, without loss of generality, a simplified sawing model based on orthogonal cutting and Thompson''''s hacksaw model for heavy-load cutting process was developed to predict the feeding force by employing the concept of cutting energy and to construct the relations between cutting parameters and the cutting rate. Moreover, the correctness of assumptions and the sawing model was verified by the experimental investigation. Finally, based on the model established in this paper and by taking the effects of clogging chip and blade deflection on the cutting rate into consideration, the optimum cutting length (L#) is determined. Consequently, a strategy for the modification of the motion of the bandsaw mechanism for obtaining the highest cutting rate was proposed.
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Hsu, Hsin-Yu, and 許欣瑜. "Robust Resign and Process Optimization For QFN Package Sawing." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/65tk99.
Full textAbstract:
碩士國立高雄應用科技大學
工業工程與管理系碩士在職專班
102
In recent years, the electronic products changed so fast, and Taiwan suffer the tough competition with Korea in the semi-conduct industry. Nowadays, the consumer IC are getting thinner, and getting higher technique. Therefore, we must upgrade the IC package technology, and improve the process flow to increase the benefits of products and reduce the failure rate. Thus, we will get higher product quality and customer’s satisfaction. According to the six sigma management tactics ” DAMIC” and Taguchi’s robust design method, we can find out the key factor and optima condition of production. And we also can establish the quality control system to take care of the production stability, yield & quality to reduce the abnormal issue happened. Taking the QFN series products for example, we can use the six sigma management tactics ” DAMIC” and Taguchi’s robust design method to increase the CPK of lead burr from 1.0 to 1.84.And it is significant of production ability improvement, and will reduce the production cost by the analysis module.
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Hsieh, Chi-liang, and 謝其良. "UV laser processing technology applied GaAs wafer sawing reserch." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/agcvx4.
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碩士國立高雄大學
電機工程學系--先進電子構裝技術產業研發碩士專班
102
GaAs wafer is a brittle material, there are problems in traditional diamond sawing such as die cracking, edge chipping and peeling. Therefore it is important to develop an alternative solution of die sawing for GaAs related device packaging. It is known that laser cutting has advantages of high precision and through put. In this thesis we downstate the sawing of GaAs die by UV laser of 355nm . In this experiment, we study laser sawing parameter in term of laser power. vepertion rate and cutting velocity. In addition a simple model of laser cutting is proposed to evaluate the laser cutting efficiency of GaAs wafer . As a conclusion ,an optimized laser cutting parameters were achieved and is helpful to apply in GaAs related device package process.
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Tsai, Hsin-Jung, and 蔡欣蓉. "Feasibility Study on Wet Etching for Wafer Sawing Technology." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/55765310936430933691.
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碩士國立臺灣科技大學
化學工程系
103
In this work, the feasibility to combine multi-wire sawing and metal-assisted chemical etching (MaCE) processes for silicon wafer cutting technology is studied. First, layers of Pt metal were deposited on stainless steel substrate via electroless plating method and the prepared material was used for the surface modification of silicon wafer by MaCE. Next, a mixture design method was adopt in order to facilitate the process of finding the best ratio among etchant chemicals. Finally, the effects caused by different etching conditions were evaluated by SEM and surface profile measurements. It was found that uniform and dense Pt layers were successfully deposited on stainless steel by electroless plating, where the IPA and DI water diluted solutions were alternatively used in each plating cycle. As to the surface modification of silicon wafer by MaCE, the fastest etching rate was 16.348 m/min and 7.699 m/min respectively for (100) and (111) silicon, wherein the optimal combination of etchant chemicals was found HF：H2O2：TFA= 4：4：4.
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Wu, Ping-Chien, and 吳秉謙. "Contour detection on wafer sawing-lane and wild animals." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/18198298056229018480.
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碩士國立高雄應用科技大學
光電與通訊研究所
96
The thesis contains two subjects：wafer sawing-lane inspection and contour detection on wild animals. Today, there is no doubt that diamond wafer sawing is a viable method for the die separation of microelectronic substrates. However, reality dictates that much careful planning and control over many variables is necessary in order to create the required efficient sawing system. Material type, depth of cut, desired throughput, feed rates, spindle speed, and blade flange design, are but a partial list of the variable components affecting the sawing operation. Also, because of the mechanical constraints induced by sawing, chips corners tend to break easily thus rendering the pieces unusable. This means a large amount of scrap wafers are required for qualifications. In this thesis, a wafer sawing lane inspector has been designed to suit in a production line environment, and help NXP Semiconductor Co. at Kaohsiung check if the lane width is manufactured to specification. We present an efficient algorithm for sawing lane extraction based on modified YCbCr color processing, 10 × 10 crossed template matching, energy transformation and analysis, and sawing lane localization via local projection along horizontal and vertical directions, respectively. Then, we trace the contour of sawing lane based on 8-adjacency scheme, marks on chips that need to be checked are achieved using distances among sawing boundaries and die walls. Due to the possible translation and rotation errors caused by the x-y table of the mechanism or improper sawing, the orientation of lane calculated by the least squares regression algorithm is carried out to prevent unsatisfactory positioning from reaching the width inspection. 30 images were used in our test dataset. Experimental results show that both the accurate acceptance rate and the accurate rejection rate are 100%, while both the false acceptance rate and the false rejection rate are 0. The running system is AMD Athlon 64 2.0 GHz CPU, which spends 0.72 second in average on processing one 640 × 480 image. Concerning about the contour detection of wild animals, we try to separate the target objects from the complicated backgrounds. We analyze the energy spectrum of the target object and perform the connected component labeling concomitantly.
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LIN, TING-CHIANG, and 林鼎將. "Surface Topography Analysis on Substrates Silicon by Wire Sawing." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/47407621491345576883.
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碩士國立臺灣科技大學
機械工程系
101
Multi-wire sawing process has been widely used to fabricate silicon substrates for solar cells application. This research is to develop the process model of wire sawing based on wire sawing analysis (WSA). Main parts of WSA include slurry viscosity factor (SVF) and slurry sensitivity (SS) obtained by ostwal-deWaele equation, the estimated of cutting kerf-loss and material removal rate (MRR). Two sawing parameters (WS-1 and WS-2) of free abrasive sawing (FAS) processes have been used to test WSA model by slicing polycrystalline silicon ingots. A viscosimeter is used to measure the slurry viscosity with variant temperature and the slurry film is calculated by dipping the wire into slurry at different temperature to estimate the kerf loss and MRR. The measured results of total thickness variation (TTV), surface topography, and subsurface damage are used to evaluate the feasibility of different slurry by slurry viscosity factor (SVF) and slurry sensitivity (SS). Fast Fourier transform (FFT) is used to analyze the frequency amplitude and frequency position of surface topography on different silicon substrates. Result of SVF as 499.98 and SS as -0.037 with WS-1 has obtained the higher kerf loss and MRR than those of WS-2 which SVF as 461.5 and SS as -0.045 after slicing. Both of subsurface damage and 3-D roughness parameters appeared better performance of WS-1 with higher viscosity. Results of this study could be used to analysis the carrier properties, surface topography, and estimate the cutting performance to investigate the effect of different cutting parameters.
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Wang, Yu-Ming, and 王喻民. "The Analysis of Sawing Process by Response Surface Methodology." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/wv26rk.
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碩士國立虎尾科技大學
機械與機電工程研究所
98
In accordance with the need to cut off during the metal processing, band saw machine processing technology is one of the current trends in machine tool industry. However, during the sawing process, problems such as collapse gear, belt as well as low cutting rates may often happened because of the increase change of cutting force or the regenerative of chatter generation. In order to avoid these problems, first, by finding out the static and dynamic response of machine tool characteristics, then the experimental design followed by the response surface methodology can adjust the cutting parameters getting good results. This paper can be divided into two parts. The first part focus on the static response test produced by the band saw machine. Observing the response from the case of static machine and analyzing the dynamic response of the band saw machine cutting caused by the impact. Then, analyzing the entire production process of chatter. It can be found that the experimental trends fit to the theoretical results. Chatters can be produced when it is high speed, small feed or slow speed, high feed. When the chatters are generated, they not only cause the unstable affect to the cutting system, but also affect the cutting performance greatly. With the view to solving this phenomenon, try to adjust the cutting parameters so the cutting conditions can avoid the instability of the cutting area, and achieve to more stable cutting region. Moreover, considering the cutting wear resistance for the sawtooth effect, therefore, the second part of this paper is focus on the system for chatter suppression with an attempt to reduce the cutting force. The experiment of cutting and cutting force amplitude quantization, better use of response surface methodology the cutting conditions, and further discussion about the cutting force, cutting amplitude and the relationship between cutting parameters for the stability of domestic band saw sawing machine designed to provide optimal basis.
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Scholl, Matthew S. "Sawing and drying of hardwood lumber from small diameter logs." 2006. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-1430/index.html.
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Leu, Wen Hwa, and 呂文華. "Synthesis and Analysis of Five-Bar Linkage for Sawing Machine." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/84069337704034234222.
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"Weaving, Sawing and Houses: A Trans-Systemic Aboriginal Rights Framework." Thesis, 2013. http://hdl.handle.net/10388/ETD-2013-12-1353.
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Chief Justice Lamer has stated that the doctrine of Aboriginal rights exists and is recognized by section 35(1) of the Canadian constitution because of the “one simple fact” that Aboriginal peoples were already here, living in what became Canada when Europeans arrived. As a result, the purpose of Aboriginal rights is to reconcile the pre-existence of Aboriginal peoples with the Crown. Yet both the conception of reconciliation and the test Lamer C.J. developed to fulfil the purpose underlying s. 35(1) are fraught with numerous problems and contradictions. This thesis adapts the relational approach in anthropology to create a trans-systemic legal framework for Aboriginal rights that allows a more equitable reconciliation than that advanced by Lamer C.J. and avoids the pitfalls of the courts’ current approach.
I begin by exploring how the Court’s conceptions of society and culture, in particular, are the source of the problems in their approach to Aboriginal rights. Focusing in on the Court’s use of “culture,” I then discuss the intellectual foundations of the notion and go through the three phases of the test for Aboriginal rights showing how those foundations have influenced it and the dilemmas and barriers “culture” creates for both the courts and Aboriginal claimants.
One of my major, continuing criticisms of the Court’s approach is that by focusing on culture, the lives and perspectives of Aboriginal claimants and their ancestors are marginalized, and so my proposed trans-systemic framework is based on “re-enlivening” Aboriginal rights. By focusing on life, rather than culture, I argue that this more ably meets the goals and purposes of s. 35(1). This refocusing also results in a different relationship between Aboriginal peoples, the Court and the Crown, and I conclude this thesis with a discussion of how the convergence of Aboriginal legal systems and the common law in Canada may occur.
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Tan, Choa-Peng, and 譚兆鵬. "Recovery of Si and SiC from spent silicon sawing slurry." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/45a25m.
Full textAbstract:
碩士國立臺北科技大學
資源工程研究所
101
In Si-ingot slicing process, a great amount of spent silicon sawing slurry is produced. Several materials in the spent silicon sawing slurry are worthy of recovery, such as glycol liquor, silicon, silicon carbide. Developing a low-cost and simple recycling process will help decrease the amount of waste and reduce the manufacturing cost. The purpose of this study is to recover silicon and silicon carbide from spent silicon sawing slurry by sedimentation and centrifugation using various carriers. The experimental results show the settling velocity of waste powders in carrier-X was faster than in other carriers, and its settling belonged to dispersed form, which was helpful of the separation of Si and SiC. When solid content was 30 wt.% for a 30-min settling using carrier-X, Si content of the upper layer increased from 30.62 wt.% to 70.3 wt.%, Fe content decreased from 7.13 wt.% to 0.87 wt.%, and the recovery percentage of Si was 68.9 wt.%. And Si content of the lower layer decreased to 1.12 wt.%, Fe content decreased 0.37 wt.%, and the recovery percentage of SiC was about 53.7 wt.%. In centrifugation experiments with 300 rpm for 1 hour, when solid content was 10 wt.%, Si content of the upper layer increased to 88.6 wt.%, Fe content was 2.6 wt.%, but the recovery percentage of Si was only 10.4 wt.%. With the operation of magnetic separation, the highest Si content reached 89 wt.% and Fe content was only 0.85 wt.%. Fe removal fraction was 88.1 wt.%, and the recovery percentage of Si was 20.2 wt.%. This study separated and concentrated Si and SiC from spent silicon sawing slurry successfully using low energy consuming, simple and environmental friendly method.