Academic literature on the topic 'Hot compression molding'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Hot compression molding.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Hot compression molding"
1
Wang, Youmin, Xiangli Li, and He Sui. "Numerical Investigation and Mold Optimization of the Automobile Coat Rack Compression Molding." Advances in Materials Science and Engineering 2021 (April 30, 2021): 1–19. http://dx.doi.org/10.1155/2021/6665753.
Full textAbstract:
In order to have more accurate control over the compression molding of automobile coat rack, improve the quality of molding products, and achieve the goal of lightweight design, a novel mechanical model for the main two-layer composite structure of the coat rack is proposed. In this regard, the main factors affecting the mechanical properties of the composite structure are obtained. The hot air convection is selected for the sheet preheating. During the experiment, the hot air temperature, preheating time, molding pressure, and pressing holding time are set to 250°C, 110 s, 13 MPa, and 80 s, respectively. Moreover, the error compensation method is applied to compensate for the shrinkage of the product during solidification and cooling. The LS-DYNA finite element software is used to simulate the molding process of the main body of the coat rack, and the node force information with large deformation is obtained accordingly. The load mapping is used as the boundary condition of mold topology optimization, and the compression molding of the main body of the coat rack is optimized. A lightweight design process and method for the compression molding of automotive interior parts and a mathematical model for the optimization of the solid isotropic material penalty (SIMP) (power law) material interpolation of the concave and convex molds are established. Based on the variable density method, OptiStruct is used for the lightweight design of the convex and concave molds of the main body of the coat rack, which reduces the mold weight by 15.6% and meets the requirements of production quality and lightweight.
2
Liu, Yi, Guan Liu, Zhan Fu, Yi Ping Li, and Hong Wu Guo. "The Pattern Simulation of New Woodiness Restructuring Decoration." Applied Mechanics and Materials 184-185 (June 2012): 1328–32. http://dx.doi.org/10.4028/www.scientific.net/amm.184-185.1328.
Full textAbstract:
This paper used pattern design, colour design and mold design comprehensively, using compression molding and simulated carving technology, studying a way to realize the pattern simulation of woodiness restructuring decoration. The result showed that it’s feasible to simulate pattern of new woodiness restructuring decoration, and the adornment effect was good. The line of the simulated pattern needed to be smooth. it’s better for the color in per unit area to be less. During the compression molding of board, the key point of decorative pattern simulation was the mould design. As adornment material instead of structural one, the technological parameters such as impregnation, pressure of hot pressing, time of hot pressing process during the process of preparation had a small effect on the adornment of board.
3
Wen, Shao Guo, Yan Shen, Ji Hu Wang, Hing Bo Liu, Qian Xu, and Shi Gao Song. "Surface Modification of the UHMW-PE Film Processing by Hot Compression Molding." Advanced Materials Research 239-242 (May 2011): 703–6. http://dx.doi.org/10.4028/www.scientific.net/amr.239-242.703.
Full textAbstract:
The properties of UHMW-PE film produced by hot compression molding and films modified by acid and anti-static agent were characterized. The results showed that: a) the thickness distributing of the film which processing by calendar rolling with conventional design roller is inhomogeneity; the tensile strength was 37.22 MPa, the elongation at break was 368.00%; the transmittance increases with wavelength redshift shows short-wave absorption and long-wave transmission; initial temperature of dissociation is 320°C; the surface resistance 1010 Ω and maximum is higher than 1016 Ω. b) Acid modification the surface of UHMW-PE film moderates the surface antistatic performance. C) After modified the film with external anti-static agent, the surface resistance was around 107Ω, but anti-static properties loss rapidly after friction. If modified the film with internal anti-static agent, the surface resistance was around 1010 Ω and have a long-lasting anti-static effect.
4
Mazur, Rogério L., Geraldo M. Cândido, Mirabel C. Rezende, and Edson C. Botelho. "Accelerated aging effects on carbon fiber PEKK composites manufactured by hot compression molding." Journal of Thermoplastic Composite Materials 29, no. 10 (2016): 1429–42. http://dx.doi.org/10.1177/0892705714564283.
Full text
5
An Zhen-Lian, Yang Qiang, Zheng Fei-Hu, and Zhang Ye-Wen. "Space charges formed in the hot compression molding process of low density polyethylene." Acta Physica Sinica 56, no. 9 (2007): 5502. http://dx.doi.org/10.7498/aps.56.5502.
Full text
6
Qian, Dongsheng, Ziyi Ye, Libo Pan, Zhijiang Zuo, Dongwang Yang, and Yonggao Yan. "The Mechanical and Thermoelectric Properties of Bi2Te3-Based Alloy Prepared by Constrained Hot Compression Technique." Metals 11, no. 7 (2021): 1060. http://dx.doi.org/10.3390/met11071060.
Full textAbstract:
This study proposes a constrained hot compression-molding (CHCM) technique for preparing Bi2Te3-based alloys. This method overcomes the problem of easy cleavage and destruction for the zone-melted Bi2Te3-based alloy, which is beneficial to improve the material utilization rate and thermoelectric devices yield in the commercial manufacturing process. The stress field distribution inside the CHCM specimen is explored via finite element analysis. The compressive strength of the CHCM sample is above 44 MPa, which is about 38% higher than that of the zone melting (ZM) material. Meanwhile, the CHCM sample shows a much lower electrical conductivity and thermal conductivity, but a higher Seebeck coefficient than that of the ZM sample, which is mainly due to the increase of the line defect concentration induced by the CHCM process. Finally, a maximum thermoelectric figure of merit (ZT) value of 0.6 was achieved for CHCM sample.
7
M. Khairul Zaimy, A. G., Anika Zafiah, M. Rus, Najibah Ab Latif, and S. Nurulsaidatulsyida. "Mechanical and Thermal Properties of Waste Bio-Polymer Compound by Hot Compression Molding Technique." JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES 5 (December 30, 2013): 582–91. http://dx.doi.org/10.15282/jmes.5.2013.4.0055.
Full text
8
Cao, Bin, Sheng Ling Xiao, and Xiao Qing Pan. "Research on Influencing Factors of Wood Residual Fiber Foaming Cushion Material." Advanced Materials Research 511 (April 2012): 46–50. http://dx.doi.org/10.4028/www.scientific.net/amr.511.46.
Full textAbstract:
A wood residual fiber foaming cushion material was prepared by using gathered wood fiber as main raw material, starch/PVA adhesive as matrix, adding a certain amount of foaming agent and related additives, hot compression molding to shape up. This paper makes an investigation of single factor on the product’s surface quality and related mechanical property. Results show that with the amount of wood residual fiber increases, the rebound resilience of the product first increases then decreases. The density decreases along with the amount of foaming agent increases. The compression strength and compression modulus of the product increases along with the amount of wood residual fiber increases, it decreases along with the amount of foaming agent increases.
9
Zhu, Zhi Yan, and Xin Gang Zhou. "The Physical and Mechanical Behavior of Hot Press Mould WPCs." Advanced Materials Research 399-401 (November 2011): 305–9. http://dx.doi.org/10.4028/www.scientific.net/amr.399-401.305.
Full textAbstract:
WPCs are wood plastic composites materials. Currently most of WPCs are manufactured by extrude technology. In order to enhance the production efficiency, a new manufacture technology called hot press molding (HPM) has been developed. The remarkable advantages of the so-called HPM WPCs are that large dimension board from 600mm×600mm×3mm to 3500mm×3500mm ×60mm can be multi-moulded in one time. In this paper, the HPM WPCs’ process mechanism and technology is introduced, and the physical and mechanical behavior of the HPM WPCs board is tested and studied. Test and research have shown that the physical and mechanical property of HPM WPCs is good. It is an idea substitute material of timber. The water absorption of HPM WPCs is only 10.3%, the moisture dilation is only 1.10%, the dimensional changes after heated is 2.31%, etc. , physical behavior is better than that of normal timber. Besides that, the mechanical behavior is better than that of timber as well. The ultimate bending strength can reach 14.1MPa, the ultimate compression strength can reach 31.3MPa, and the compression modulus is 3618MPa.
10
Fang, Li Ming, Yang Leng, and Ping Gao. "Effect of HA Content on Mechanical Properties of Hot Drawn HA/UHMWPE Nanocomposites for Bone Substitutes." Key Engineering Materials 334-335 (March 2007): 701–4. http://dx.doi.org/10.4028/www.scientific.net/kem.334-335.701.
Full textAbstract:
Hydroxyapatite reinforced ultrahigh molecular weight polyethylene (HA/UHMWPE) nanocomposites with HA volume fraction 0.1~0.5 are processed by twin-screw extrusion compounding and compression molding followed by hot drawing. SEM micrographs show that HA nano-particles are homogeneously dispersed in the highly oriented UHMWPE inter-fibrils. Tensile tests show that the modulus increases, while the strength and ductility decrease, with the increase of HA content. A good combination of mechanical properties can be obtained in the composite with HA nano-particles volume fraction 0.3.
Dissertations / Theses on the topic "Hot compression molding"
1
Kamgaing, Somoh Georges Bertrand. "Conception et caractérisation mécanique des pièces en matériaux composites moulées par compression." Thesis, Paris, ENMP, 2013. http://www.theses.fr/2013ENMP0081/document.
Full textAbstract:
Si l'emploi des matériaux composites dans l'aéronautique est déjà effectif sur des éléments de structures principales et de grande taille, leur généralisation aux structures secondaires bute sur leur positionnement en termes de coûts et performances face aux métaux. Il s'agit dans ce travail de contribuer à la mise en place d'une filière française de pièces composites hautes performances à bas coûts en s'appuyant sur un procédé de moulage en grande série, à savoir le thermoformage à haute pression. Ainsi, il a été question dans un premier temps d'optimiser ce procédé vis-à-vis des principales matières rencontrées dans les structures aéronautiques. Ensuite, les stratifiés moulés ont été caractérisés et les effets des conditions environnementales sévères (humidité, température, impact) sur leur comportement mécanique étudiés. Par ailleurs, réduire les coûts des pièces signifie également réduire les coefficients de sécurité qui restent très élevés pour les pièces composites. Cela passe par une meilleure prédictibilité de la rupture des matériaux et du comportement mécanique au-delà du linéaire. Sur le carbone/PEEK satin de 5 pris comme matériau d'illustration, les phénomènes non linéaires (viscoplasticité) ainsi que les mécanismes d'endommagement et de rupture ont été étudiés. Un accent particulier a été mis sur le délaminage et un critère permettant de prédire son amorçage a été proposé. La possibilité de faire des modèles éléments finis des pièces directement à l'échelle mésoscopique (du pli) a été également explorée et laisse entrevoir des pistes prometteuses pour des dimensionnements plus sûrs et donc moins conservatifs<br>If the use of composite materials is already effective on elements of main structures and large size parts, their generalization to secondary parts is not effective due to their cost and their performances compared to metals. The framework of this thesis is to contribute to the establishment of a French chain of high performance composite parts at low cost. Thus, it was initially question of optimizing the process vis-à-vis the main composite materials used in the aerospace structures. Then, the molded laminates were characterized and the effects of severe conditions (humidity, temperature, impact) on their mechanical behavior were studied. Also, reduce the cost of parts also means reducing the safety factors which remain very high. This requires a better prediction of the failure and the mechanical behavior beyond the linear. Taking the five harness satin weave carbon/PEEK material as example, non-linear phenomena (viscoplasticity), damage mechanisms and failure criteria were studied, with particular emphasis on the delamination. The possibility to perform finite element analysis of the parts directly at the mesoscopic scale (ply-scale) was also explored and suggests promising expectations for a less conservative sizing of composite structures
2
Oliveira, Juliana Bovi de. "Obtenção e caracterização de compósitos de epóxi/microfibras elastoméricas/fibras de carbono para aplicações aeronáuticas /." Guaratinguetá, 2020. http://hdl.handle.net/11449/192431.
Full textAbstract:
Orientador: Edson Cocchieri Botelho<br>Resumo: Esta pesquisa visa o processamento de compósitos termorrígidos laminados multifuncionais, via moldagem por compressão a quente, constituídos por fibras de carbono, resina epóxi e mantas de poli(butadieno) (BR) produzidas via processo de eletrofiação. Estas mantas têm como função proporcionar maior tenacidade ao compósito obtido, aumentando sua tolerância ao dano e consequentemente, elevando sua aplicabilidade no setor aeroespacial. Para o desenvolvimento deste trabalho de pesquisa, primeiramente, foram produzidas mantas de poli(butadieno) por eletrofiação. Todas as condições de processamento foram avaliadas nesta etapa do projeto. Posteriormente, estas mantas foram utilizadas para a obtenção de diferentes compósitos com resina epóxi e fibra de carbono, utilizando-se oito distintas configurações, processados via moldagem por compressão a quente. A qualidade dos compósitos fabricados foi avaliada a partir de ensaios de digestão ácida, microscopia, análise dinâmico mecânica (DMA) e inspeção acústica por ultrassom. Com o intuito de se avaliar eventuais ganhos na tenacidade à fratura dos laminados, foram realizados ensaios de excitação por impulso e resistência ao impacto, o qual foi seguido pela técnica de ultrassom. Também foram realizados ensaios de End-Notched Flexure (ENF) pelo modo II de fratura (modo de deslizamento) e ensaios de cisalhamento interlaminar (ILSS) e após os respectivos ensaios, os compósitos também foram avaliados por microscopia. A partir da técnica de eletr... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: This research aims the processing of multifunctional laminated thermosetting composites by hot compression molding, consisting of carbon fibers, epoxy resin and polybutadiene (BR) mats produced by electrospinning. These mats can provide greater toughness to the composite obtained, increasing its damage tolerance and consequently increasing its applicability in the aerospace field. For the development of this research, polybutadiene mats were produced by the electrospinning process. All processing conditions were evaluated at this stage of the project. Subsequently, these mats were used to obtain different epoxy resin/ carbon fiber composites with 8 distinct configurations, processed by hot compression molding process. The quality of the manufactured composites was evaluated using acid digestion tests, microscopy, dynamic mechanical analysis (DMA) and acustic inspection by ultrasound. After processing, in order to evaluate possible gains in fracture toughness, these laminates were submitted impulse excitation tests, impact resistance, and after tests the specimens were analyzed by ultrasound. Also, End-Notched Flexure (ENF) testes were performed using mode II fracture (sliding mode) and interlaminar shear tests (ILSS) and after the respective tests, the composites were also evaluated by microscopy. Using the electrospinning technique, it was possible to manufacture polybutadiene microfibers successfully, and use them to process laminated composites consisting of carbon fibers ... (Complete abstract click electronic access below)<br>Doutor
3
Conejo, Luíza dos Santos. "Processamento e caracterização de compósitos multifuncionais de resina furfurílica/CNT/fibra de carbono /." Guaratinguetá, 2019. http://hdl.handle.net/11449/181895.
Full textAbstract:
Orientador: Edson Cocchieri Botelho<br>Resumo: Este trabalho de pesquisa consiste na obtenção e caracterizações térmica, mecânica, reológica e elétrica de compósitos multifuncionais obtidos a partir da utilização de fibras de carbono (FC), resina furfurílica (RF) e nanotubos de carbono (CNT) para aplicações aeroespaciais. O uso de uma bioresina como fonte alternativa ao petróleo em compósitos multifuncionais e a avaliação dos ganhos de propriedades na utilização de nanotubos de carbono (0, 1,3 e 2,5% em volume) associados a fibras contínuas de carbono (tecido plain weave) são os objetivos principais deste trabalho. O desenvolvimento deste trabalho de pesquisa estabelece os parâmetros de processo mais adequados para a obtenção de compósitos multifuncionais com propósitos estruturais, térmicos e/ou elétricos. Neste trabalho, os compósitos multifuncionais foram processados com a utilização de moldagem por compressão a quente, sendo esta uma das contribuições desta dissertação. Após processados, os laminados foram avaliados a partir de ensaios mecânicos (cisalhamento interlaminar por compression shear test (CST), impacto a baixas velocidades, DCB (Double Cantilever Beam test), ENF (End Notched Flexure) e fadiga); assim como, a partir de análises térmicas (DMA (Análise Dinâmico-Mecânica), DSC (Calorimetria Exploratória Diferencial), TGA (Análise Termogravimétrica) e TMA (Análise Termomecânica)), ensaios elétricos, análises morfológicas (MO (Microscopia Óptica), MEV (Microscopia Eletrônica de Varredura) e ultrassom) e análises ... (Resumo completo, clicar acesso eletrônico abaixo)<br>Doutor
Book chapters on the topic "Hot compression molding"
1
Kuswoyo, Andi, Lies Banowati, Khodijah Kholish Rumayshah, and Bambang Kismono Hadi. "Impact Strength of Ramie/HDPE Composites Manufactured Using Hot Compression Molding." In Advances in Lightweight Materials and Structures. Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-7827-4_43.
Full text
2
Han, Chang Dae. "Compression Molding of Thermoset/Fiber Composites." In Rheology and Processing of Polymeric Materials: Volume 2: Polymer Processing. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780195187830.003.0019.
Full textAbstract:
Glass-fiber-reinforced thermoset composites have long been used by the plastics industry. Two primary reasons for using glass fibers as reinforcement of thermosets are: (1) to improve the mechanical/physical properties (e.g., tensile modulus, dimensional stability, fatigue endurance, deformation under load, hardness, or abrasion resistance) of the thermosets, and (2) to reduce the cost of production by replacing expensive resins with inexpensive glass fibers. In place of metals, the automotive industry uses glassfiber- reinforced unsaturated polyester composites. One reason for this substitution is that the weight per unit volume of composite materials is quite low compared with that of metals. This has allowed for considerable reductions in the fuel consumption of automobiles. Another reason is that composite materials are less expensive than metals. The unsaturated polyester premix molding compounds in commercial use are supplied as sheet molding compound (SMC), bulk molding compound (BMC), or thick molding compound (TMC) (Bruins 1976; Parkyn et al. 1967). These molding compounds can be molded in standard compression or transfer molds. The basic challenge in molding unsaturated polyester premix compounds is to get a uniform layer of glass reinforcement in place in the die cavity while the resin fills the cavity and reaches its gel stage during cure. Temperature, mold closing speed, pressure, and cure time are all functions of the design of the part being produced. The flow of the mixture through the gate(s) can result in variations in strength across the part due to fiber orientation during the flow. The precise end-use properties depend on the fiber orientation, fiber distribution, and fiber content in the premix compounds, which are greatly influenced by the processing conditions. Since the mechanical properties of the molded articles depend strongly upon the orientation of the glass fibers, it is important to understand how to control fiber orientation during molding. Unsaturated polyester accounts for the greater part of all thermosets used in glass-fiber-reinforced plastics. Glass-fiber-reinforced unsaturated polyesters offer the advantages of a balance of good mechanical, chemical, and electrical properties. Depending upon the application, a number of additives are employed to provide specific products or end-use properties.
Conference papers on the topic "Hot compression molding"
1
Kobayashi, Satoshi, and Toshiko Osada. "Experimental and Analytical Resin Impregnation Characterization in Carbon Fiber Reinforced Thermoplastic Composites." In JSME 2020 Conference on Leading Edge Manufacturing/Materials and Processing. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/lemp2020-8627.
Full textAbstract:
Abstract Effect of molding condition on resin impregnation behavior and the associated mechanical properties were investigated for carbon fabric reinforced thermoplastic composites. Carbon fiber yarn (TORAYCA, Toray) was used as a reinforcement, and thermoplastic PI (AURUM PL 450 C, Mitsui Chemicals) was used as the matrix. CFRTP textile composites were compression-molded with a hot press system under the molding temperature, 390 °C, 410 °C and 430 °C, molding pressure 2 MPa and 4 MPa and molding time 0∼300 s. In order to evaluate the impregnated state, cross sectional observation was performed with an optical microscope. Specimen cross-section was polished and finished with alumina slurry for a clear observation. The images observed were processed through image processing software to obtained impregnation ratio which defined as the resin impregnation area to the cross-sectional area of a fiber yarn. Resin impregnation was accelerated with molding temperature and pressure. At molding temperature more than 410 °C, resin impregnation was similar irrespective of temperature. Tensile test results indicated that modulus and strength increased with resin impregnation. Resin impregnation during molding was predicted using the analytical model based on Darcy’s law and continuity condition. The analysis could successfully predict the impregnation behavior despite the difference in molding pressure and temperature.
2
Marcotte, Jean-Philippe, Kalonji K. Kabanemi, and Jean-Franc¸ois He´tu. "Numerical Modeling and Experimental Study of Hot-Embossing Process for Manufacturing of Microcomponents." In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-10488.
Full textAbstract:
Hot embossing is a compression molding technique used for high replication accuracy of small features. One of the most sensitive phases of the process is the de-embossing stage during which the patterned part has to be demolded. In this paper, the demolding stage is considered as a frictional contact problem between a rigid mold insert and a viscoelastic polymer sheet as it deforms and cools inside a mold under an applied force. The contact is modeled with a modified Coulomb’s law of dry friction while a generalized Maxwell model is used to describe the polymer behavior during embossing, cooling and de-embossing stages. The heat transfer between the mold insert and the patterned polymer sheet is solved through a domain decomposition method. A finite element approximation based on a penalized technique is proposed and analyzed. The purpose of this modeling approach is to predict dimensional stability and residual shape of microcomponents in the hot embossing process. Such a prediction will allow one to assign appropriate processing conditions that minimize geometrical imperfections and increase replication accuracy.
3
Jiang, Kaiyu, Keqian Cai, Minjie Wang, Danyang Zhao, and Zhong You. "Experimental Study of Manufacture and Mechanical Behavior of Sandwich Structure With Composite Foldcores." In ASME 2015 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/detc2015-47022.
Full textAbstract:
Foldcore Sandwich structures with high specific strength and specific stiffness will be the aeronautic and astronautic main load-carrying structure materials. Curing process temperature of the Carbon and Kevlar prepreg materials were determined by the best curing process extrapolation method. And then, three dimensional foldcore specimens were manufactured by hot-pressing and piecewise curing molding process. In the compression test, compression force-displacement variation laws and deformation failure modes of the foldcores with different thickness were studied by changing the thickness of core wall. Furthermore, the panel constraints on the properties of compression are studied by pasting panel on the bottom of core and both sides of the core. The researches shows: the compression strength and compression modulus was multiplied increased, and the brittle degree of core was increased with the core wall thickness increasing. The panel restriction for foldcore greatly improved the compression modulus and compression strength.
4
Song, Ruoyuan, Haruhiro Ino, and Teruo Kimura. "Mechanical Properties of PBS Plastic Reinforced by Paper Using Waste Silk." In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-12742.
Full textAbstract:
Considering the efficient recycling of waste silk resource, the biodegradable composite consisting of PBS matrix and pure silk paper was prepared by hot compression molding. Beating treatment is adopted to modify silk fibroin and enhance the composite, and the corresponding mechanical properties and morphologies were studied detailedly. The results showed that beating treatment could realize the fibrillation of fibroin and improve the paper’s tensile strength, and proper beating treatment to fibroin could also improve the mechanical properties of silk paper reinforced PBS composite. The tensile, flexural and impact resistance properties of this green composite were improved remarkably with fiber loading increasing. Especially for impact resistance, it was improved 154% at 40 wt% fiber loading compared with PBS control.
5
Zhang, Qi, and Pierre Mertiny. "Effect of Graphene Nanoplatelet Addition on the Conductive Behavior of Solution Mixing Processed Polylactide Biopolymer Nanocomposites." In ASME 2019 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/imece2019-12053.
Full textAbstract:
Abstract The fabrication of highly thermally and electrically conductive polymer materials is of interest for multiple applications, for example, in electronics packaging and biosensors. Polylactic acid (PLA), a commercially available and biodegradable polyesters, is widely used and studied since it is considered a environmentally friendly alternative to petrochemical-based synthetic polymers. In the present study, graphene nanoplatelets (GNP) reinforced PLA composites were prepared via solution blending followed by a compression molding process. Various physical and thermo-mechanical analyses were performed with the prepared composites. For instance, the electrical conductivity of PLA/GNP composites at various filler loadings was determined using four-point probe resistivity measurements. An electrical conductivity of 0.1 S/cm was achieved at a GNP loading of 12 wt%. Using the hot-disk transient plane source method, anisotropic thermal conductivity properties were evaluated. An in-plane and through-plane thermal conductivity of 0.87 W/mK and 0.58 W/mK was achieved with the addition of 6 wt% GNP, which is a nearly twofold and over fourfold increase compared to neat PLA, respectively.
6
Ashrafi, Mahdi, Masoud Olia, Ashkan Vaziri, and Hamid Nayeb-Hashemi. "Optimizing the Mechanical Properties of Wood Plastic Composites Using Fiber-Glass." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-64043.
Full textAbstract:
Wood plastic composites (WPC) are widely used in the industry due to its durability, low cost, and anti-moisture properties in comparison with the natural wood. Recently, WPC are also being considered in musical instrument industry. In this research, we have produced flout shaped WPC samples using African black wood powder and Phenolic resin in a hot compression molding set-up. Initial WPC composites were produced by systematically changing the wood volume fraction. The results showed cracks developed in composites with more than 70% wood. This was related to formation of gas in the system during manufacturing and lack of fluidity in the system to flush the gases. Based on these results the optimum temperature, pressure and wood volume fraction for developing WPC in a form of a flute is developed. A series of experimental procedures were performed to improve mechanical properties of WPC samples by studying the effect short fiber-glass addition to the wood matrix prior to hot pressing. The results showed that the addition of short fiber did not improve the strength of WPC but rather than it reduced its strength compared to unreinforced composite. This was attributed to lack of bonding between short fibers and wood matrix. In contrast encapsulated wood particle composite in an E-glass/epoxy composite sheet before hot pressing showed the mechanical properties of wood composite are enhanced. A two layer unidirectional composite was sufficient for producing flute with desirable mechanical properties. On the basis of the experimental results, a very simple method to enhance the load-bearing capability of WPC which may allow producing reinforced WPC in the form of flout shape is developed.
7
Vick, Michael, Trent Young, Matthew Kelly, Steven Tuttle, and Katherine Hinnant. "A Simple Recuperated Ceramic Microturbine: Design Concept, Cycle Analysis, and Recuperator Component Prototype Tests." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-57780.
Full textAbstract:
Ceramic recuperators could enable microturbines to achieve higher fuel efficiency and specific power. Challenges include finding a suitable ceramic fabrication process, minimizing stray heat transfer and gas leakage, mitigating thermal stress, and joining the ceramic parts to neighboring metal components. This paper describes engine and recuperator design concepts intended to address these obstacles. The engine is sized to produce twelve kilowatts of shaft power, and it has a reverse-flow compressor and turbine. Motivations for this layout are to balance axial thrust forces on the rotor assembly; to minimize gas leakage along the rotating shaft; to reduce heat transfer to the compressor diffuser; to enable the use of a simple, single-can combustor; and to provide room for lightweight ceramic insulation surrounding all hot section components. The recuperator is an annular, radial counterflow heat exchanger with the can combustor at the center. It is assembled from segmented wafers made by ceramic injection molding (CIM). These are housed in a pressure vessel to load the walls mainly in compression, and are joined together by flexible adhesives in the cool areas to accommodate thermal expansion. A representative wafer stack was built by laser-cutting, laminating, and sintering tapecast ceramic material. The prototype was tested at temperatures up to 675°C, and the results were used to validate analytical and computational fluid dynamics (CFD) models, which were then used to estimate the effectiveness of the actual design. Turbomachinery efficiencies were also calculated using CFD, and allowances were made for additional losses like bearing friction and gas leakage. Based on these component performance estimates, a cycle model indicates the engine could achieve a net fuel-to-electrical efficiency of 21%, at a core weight including the recuperator of 11 kg, or about 1 kg/kW electric output.
8
Zhang, Weizhao, Zixuan Zhang, Jie Lu, et al. "Experimental Characterization of the Interaction Between Carbon Fiber Composite Prepregs During the Preforming Process." In ASME 2017 12th International Manufacturing Science and Engineering Conference collocated with the JSME/ASME 2017 6th International Conference on Materials and Processing. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/msec2017-2973.
Full textAbstract:
Carbon fiber composites have received growing attention because of their high performance. One economic method to manufacturing the composite parts is the sequence of forming followed by the compression molding process. In this sequence, the preforming procedure forms the prepreg, which is the composite with the uncured resin, to the product geometry while the molding process cures the resin. Slip between different prepreg layers is observed in the preforming step and this paper reports a method to characterize the properties of the interaction between different prepreg layers, which is critical to predictive modeling and design optimization. An experimental setup was established to evaluate the interactions at various industrial production conditions. The experimental results were analyzed for an in-depth understanding about how the temperature, the relative sliding speed, and the fiber orientation affect the tangential interaction between two prepreg layers. The interaction factors measured from these experiments will be implemented in the computational preforming program.
9
Anderson, Jacob P., and M. Cengiz Altan. "Properties of Composite Cylinders Fabricated by Bladder Assisted Composite Manufacturing (BACM)." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-65285.
Full textAbstract:
An innovative manufacturing method, BACM (Bladder Assisted Composite Manufacturing), to fabricate geometrically complex, hollow parts made of polymeric composite materials is presented. BACM uses an internally heated bladder to provide the consolidation pressure at the required cure temperature, and thus produces high quality components. The feasibility of this manufacturing method is demonstrated by fabricating laminated composite cylinders using multiple cure pressures and wall thicknesses. The mechanical properties, energy consumed during the curing, and void content of the composite cylinders, are investigated in detail. The curing of composite cylinders was carried out by circulating heated air inside the bladder. Using the described heating method a number of 2-, 4-, and 6-ply composite cylinders made of E-glass/epoxy prepreg (Newport 321/7781) were prepared as test samples. Cylinders were cured at 121°C (250°F) for 2 hours using bladder pressures of 207 kPa (30 psi), 345 kPa (50 psi), 483 kPa (70 psi), and 621 kPa (90 psi). The mechanical behavior of the cylinders were characterized by compressing sample rings and loading ring segments in three-point bending. The fiber volume fraction and the void content of the cylinders were determined from resin burn-off experiments and density measurements. The cylinders produced using the BACM process were found to exhibit excellent surface quality. The elastic moduli, failure strength, and void contents of the cylinders were comparable to the values obtained from flat laminates produced by hot plate molding. Compared to conventional bladder manufacturing methods, the BACM process reduced the energy required to cure the cylinder by more than 50%.