Academic literature on the topic 'Plastic additive'

This project was initiated by Dr. Sasan Dadbaksh upon listening to the requirements I presented for my master thesis. My requirements were to do a master thesis project in the field of additive manufacturing specifically fused deposition modeling that should not only involve the research work but should also present an opportunity to develop hardware and should involve experimental testing. Then Sasan came up with the idea of developing a system capable to perform 3D printing with the extruder fixed in one position and the motion required for 3D printing will be provided by the robotic arm. The title of developing green build strategies for robot assisted plastic 3D printing came into being. The main concept behind the title of developing robot assisted plastic 3D printing platform is to develop such a system that can offer additive manufacturing services, specifically of fused deposition modeling 3D printing, as an inbound process during the manufacturing of any part through subtractive processes with the help of a robotic arm along with the repair of any kind of parts with the assistance of fused deposition modeling 3D printing. The main objectives of the master thesis include building a stationary filament extrusion module to interact with a robot hand and establishing a strategy for a robot hand to move the part to appropriate locations to complete building a part on a preform without support structures. The targets that were achieved with the completion of this thesis project includes the development of the complete hardware that consists of a mechanical structure with the option of mounting the components required to run the extrusion setup, learning the basic working of the software that are able to simulate the 3D printing process with the robotic arm (Robot Studio and Robo DK), creation of the simulation of the whole process, achieving communication between the robotic arm and the microcontroller of the extruder and finally the printing of a simple part for the demonstration. The components needed to be installed on the structure includes the motor, extruder, hot end, nozzle, filament. The structure also accumulated the required electronics that includes power supply, microcontroller, and an LCD to monitor the extrusion parameters. The developed machine runs on the state-of-the-art components that belong to the few of the best manufacturers of the technology.

Two direct consolidation methods usually used for advanced ceramics have been combined in this project in order to develop a novel fabrication route for traditional ceramics. Specifically the method used is based on the Additive Manufacturing extrusion process using direct writing of high solid loading ceramic pastes and then freeze-casting to solidify the deposited material. This novel fabrication method, for which a patent has been granted, has been christened “Direct Writing Freeze-Casting” (DWFC). Although the DWFC process is the subject of investigation by other researchers for a range of different applications, including the production of medical implants with alumina, the research presented in this thesis focuses on its use in the manufacture of white wares, giftware, and applied arts and crafts in general. This new system will provide designers, potters, artists, craft makers and manufacturers with a flexible and automated way of manufacturing porcelain objects. One of the major challenges to be overcome to exploit the DWFC process is the development of suitable slurry material formulations. Initial trials demonstrated that it is not possible to use conventional clay based porcelain materials with a platelet shaped microstructure which inhibits freeze casting. In this thesis the development and characterisation of non plastic porcelain slurry, based on substitution of kaolin (clay) with a calcined clay material (molochite), which can be processed using this new method is presented. The new non plastic porcelain formulation, which has a high solid load of 75.47% wt., has been subjected to detailed analysis to assess its suitability at each stage of the process; extrusion, freeze-casting (solidification) and firing.

Metal additive manufacturing stands poised to disrupt multiple industries with high material use efficiency and complex part production capabilities, however many technologies deposit material with sub-optimal properties, limiting their use. This decrease in performance largely stems from porosity laden parts, and asymmetric solidification-based microstructures. Solid-state additive manufacturing techniques bypass these flaws, using deformation and diffusion phenomena to bond material together layer by layer. Among these techniques, Additive Friction Stir Deposition (AFSD), stands out as unique for its freeform nature, and thermomechanical conditions during material processing. Leveraging its solid-state behavior, optimized microstructures produced by AFSD can reach performance levels near, at, or even above traditionally prepared metals. A strong understanding of the material conditions during AFSD and the phenomena responsible for microstructure evolution. Here we discuss two works aimed at improving the state of knowledge surrounding AFSD, promoting future microstructure optimization. First, a parametric study is performed, finding a wide array of producible microstructures across two material systems. In the second work, a stop-action type experiment is employed to observe the dynamic microstructure evolution across the AFSD material flow pathway, finding specific thermomechanical regimes that occur within. Finally, multiple conventional alloy systems are discussed as their microstructure evolution pertains to AFSD, as well as some more unique systems previously limited to small lab scale techniques, but now producible in bulk due to the additive nature of AFSD.<br>Doctor of Philosophy<br>The microstructure of a material describes the atomic behavior at multiple length scales. In metals this microstructure generally revolves around the behavior of millions of individual crystals of metal combined to form the bulk material. The state and behavior of these crystals and the atoms that make them up influence the strength and usability of the material and can be observed using various high fidelity characterization techniques. In metal additive manufacturing (i.e. 3D printing) the microstructure experiences rapid and severe changes which can alter the final properties of the material, typical to a detrimental effect. Given the other benefits of additive manufacturing such as reduced costs and complex part creation, there is desire to predict and control the microstructure evolution to maximize the usability of printed material. Here, the microstructure evolution in a solid-state metal additive manufacturing, Additive Friction Stir Deposition (AFSD), is investigated for different metal material systems. The solid-state nature of AFSD means no melting of the metal occurs during processing, with deformation forcing material together layer by layer. The conditions experienced by the material during printing are in a thermomechanical regime, with both heating and deformation applied, akin to common blacksmithing. In this work specific microstructure evolution phenomena are discussed for multiple materials, highlighting how AFSD processing can be adjusted to change the resulting microstructure and properties. Additionally, specific AFSD process interactions are studied and described to provide better insight into cumulative microstructure evolution throughout the process. This work provides the groundwork for investigating microstructure evolution in AFSD, as well as evidence and results for a number of popular metal systems.

Additive Manufacturing Technologies (AMT) are a collection of manufacturing processes driven by CAD data to produce physical models and parts by means of additive techniques. They are based on a layer-by-layer material consolidation process instead of the traditional methods. Due to machine and material developments, such processes may be used to produce final products, not only prototypes. The use of AMT to produce end-use parts is known as Rapid Manufacturing (RM). The main advantages AMT are related to the ability to build geometrically complex shapes without tooling and with high process automation. At small lot sizes, such as with customized products, traditional manufacturing technologies become expensive due to high costs of required tooling. Small lot sizes and complex shaped parts are typical features encountered in the aircraft industry. Nowadays, two Additive Manufacturing Technologies are able to process plastic materials which comply flammability requirements: Fused Deposition Modeling (FDM) and Selective Laser Sintering (SLS). The main objective of this work is to propose a decision support method based on processes technological information concerning Rapid Manufacturing of plastic parts for aircraft cabin interiors. Thus, both FDM and SLS process are compared regarding their functionality (software interface), tensile strength, accuracy and part definition, surface roughness, build time and costs. The analyzed materials are the Polyamide with flame retardant (PA2210FR) additives and the Polyphenylsulfone (PPSF) for SLS and FDM process respectively. These materials were selected because they were the available flame retardant materials for AMT as the beginning of this work. A method is proposed to consider AMT possible advantages and restrictions when considering the manufacturing process. It is proposed that design modifications to improve part';s functionality or performance may be manufactured by AMT. Further, the method proposes the decision procedure to evaluate quality, production time and cost. The author illustrates the method with examples on the selection of manufacturing technology to produce a customized decoration part and an air duct. Typical costs and manufacturing time of injection molding processes were also compared and analyzed with the proposed method. It is possible to define the break-even point, when conventional processes become preferred then AMT.

Thesis: S.B., Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2017.<br>This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Page 37 blank. Cataloged from student-submitted PDF version of thesis.<br>Includes bibliographical references (pages 33-36).<br>Portland cement based concrete production contributes heavily to greenhouse gas emissions. Thus a need exists for the development of durable and sustainable concrete with a lower carbon footprint. This can be achieved when Portland cement is partially replaced with another material without compromising the concrete's strength. The use of waste plastics in concrete has been explored as a means of improving concrete's mechanical properties while also providing an efficient way to both re-purpose waste plastic and partially displace cement for the purpose of reducing carbon emissions. This replacement, however, typically comes with a sacrifice of compressive strength. This work discusses the design for and progress toward a high-strength concrete with a dense cementious matrix that contains an irradiated plastic additive. Cement samples containing various combinations of cement binder and plastic content were prepared; compressive strength tests showed that for all cement binder types, the addition of high dose irradiated plastic resulted in increased compressive strength as compared to the strengths achieved by samples with regular, non-irradiated plastic. This suggests that irradiating plastic at a high dose is a viable potential solution for gaining some of the strength back that is lost when plastic is added to concrete. To assess the internal structure of the samples and gain some insight into what aspects of their chemical compositions' contributed to the observed strength differences, a microstructural analysis -- consisting of XRD, SEM, and X-ray microtomography -- was performed. XRD analysis showed that various differences in C-S-H and C-A-S-H phase formation from the addition of both irradiated plastic and mineral additives helped to form high-density phases that contributed to higher relative strengths. BSE analysis showed that an increased alumina content among fly ash samples helped to form the high-density phases that contributed to higher relative strength among the fly ash samples, as evidenced through a ternary phase diagram. X-ray microtomography showed that the addition of high dose irradiated plastic consistently contributed to a decrease in segmented porosity, indicating that irradiated plastic may have acted as a pore-blocking agent. The results presented clearly show the benefit of using irradiated plastic as a concrete additive for improved compressive strength. By partially replacing Portland cement with a repurposed waste material, this design, when scaled to the level of mass concrete production, could contribute to reduced carbon emissions and provide a long-term solution for waste plastic storage.<br>by Carolyn Schaefer.<br>S.B.

As additive manufacturing gains market potential as a mainstream process in various sectors of industry, there is a growing need for addressing environmental aspects of this technology and the materials associated with it. In this master thesis, comparative life cycle assessments (LCAs) from cradle to grave between the conventional products and 3D-printed alternatives made of wood-plastic composite (WPC) were conducted based on the ISO 14044:2006 standard. Environmental impacts of each product were quantified for 10 impact categories. The goal of the LCAs was to determine whether the use of the 3D-printed WPC products may suggest a sustainable alternative to the conventional ones. This master thesis presents three case studies in which comparative LCAs were carried out. The first two case studies are about storage compartments for trucks from Scania, and the third one is about ceiling boards from Veidekke. The results showed that,  in  all  case  studies,  the  3D-printed  WPC alternatives  would  have smaller environmental   impacts   compared   with   the   conventional   products. The   most significant difference was observed in the first two case studies because of the light- weighting effect. The alternatives showed 51%, 68% and 13% lower global warming potential  (GWP)  than  the conventional  products  in  each  case study,  respectively. However, the results of the cradle-to-gate LCAs suggested that the 3D-printed WPC alternative might cause greater environmental impact than the conventional products regarding some impact categories. Therefore, in the LCA context, the 3D-printed WPC alternatives would be much more beneficial to the environment compared with the conventional products, but theenvironmental benefits might be insignificant from the manufacturer’s perspective.<br>Eftersom   additive   tillverkningsteknik   ökar   marknadspotentialen   som   en vanlig process  inom  olika  industrisektorer,  finns  det  ett  växande  behov av att ta  itu  med miljöaspekterna av denna teknik och de material som är associerade med den. I detta examensarbete avhandling genomfördes jämförande livscykelanalys (LCA) från vagga till   grav   mellan   de konventionella   produkterna   och   3D-printade   alternativ   av träplastkomposit (WPC) baserat på ISO 14044: 2006-standarden. Miljöpåverkan av varje produkt kvantifierades för 10 miljöeffekter. Målet med LCA var att avgöra om användningen av de 3D-printade WPC-produkterna kan vara ett hållbart alternativ till de konventionella. Denna avhandling presenterar tre fallstudier där jämförande LCA utfördes. De två första fallstudierna handlar om förvaringsutrymmen för lastbilar från Scania, och den tredje om takskivor från Veidekke. Resultaten visade att de 3D- printade WPC- alternativen   i   alla   fallstudier   skulle   ha   mindre   miljöpåverkan   jämfört   med konventionella  produkter.  Den  mest signifikanta  skillnaden observerades  i  de  två första  fallstudierna  på  grund av  den  lägre  vikte viktningseffekten.  Alternativen visade   51%,   68%   och   13%   lägre   global uppvärmningspotential   (GWP)   än   de konventionella produkterna i respektive fallstudie. Emellertid föreslog resultaten av vaggan-till-grind-LCA   att   det   3D-printade   WPC-alternativet   kan   orsaka   större miljöpåverkan än de konventionella produkterna avseende vissa miljöeffekter. Därför,   i   LCA-sammanhang,   skulle   de   3D-printade   WPC-alternativen   vara mycket  mer  fördelaktiga  för  miljön  jämfört  med  konventionella produkter, men miljöfördelarna kan vara obetydliga ur tillverkarens perspektiv.

Il crescente impiego di tecnologie inerenti al campo dell’additive manufacturing nel settore della produzione industriale necessita di testimonianze scientifiche su quelli che possono essere gli impatti ambientali connessi all’utilizzo di questo tipo di processi. Questo documento si propone di analizzare attraverso lo strumento di Life Cycle Assessment (LCA) la tecnologia additiva Arburg Plastic Freeforming (APF) con un approccio del tipo “Craddle to Gate”. Tale studio vuole fornire un modello di riferimento in grado di valutare gli impatti ambientali legati ad una lavorazione additiva che fonda i suoi meccanismi sulle dinamiche dello stampaggio ad iniezione. Il modello proposto va interpretato come uno strumento di supporto per le fasi di progettazione di un nuovo processo/prodotto, indirizzando le scelte operative nella direzione della sostenibilità. Il sistema viene mappato nel suo insieme in funzione di tutte le fasi connesse al ciclo di vita del prodotto. L'unità funzionale rispetto cui rapportare gli impatti ambientali è l’oggetto costruito attraverso lavorazione additiva: per quantificare efficacemente gli impatti, lo studio introduce come parametri di allocazione la massa del prodotto da realizzare ed il tempo di costruzione. Il modello è stato applicato coerentemente alla fabbricazione di un oggetto, presentando gli impatti ambientali attraverso due step procedurali: visualizzazione dei MidPoint (MP) ed EndPoint (EP), calcolati mediante ReCiPe v.1.1 in una prospettiva gerarchica. Vengono poi riportati i risultati ottenuti rispetto i quali è possibile individuare i contributi maggiormente influenti del processo in termini ambientali. Vengono proposti quelli che sono i parametri maggiormente impattanti della lavorazione. Sono presentate inoltre le dinamiche relative ad analisi comparative che modellano il confronto tra due materiali costitutivi sottoposti alla stessa lavorazione, di cui se ne riportano i risultati.

Recently additive manufacturing (AM) is rapidly growing and evolving due to the advancements made in speed, quality, resolution and performance. Consequently, AM is starting to become, beyond prototyping, increasingly important for the manufacturing of end-use parts. Several successful case studies are reported and companies are starting to investigate in the opportunities of using AM for production processes and supply chain integrations.   The purpose of this research is to evaluate the potential of using AM for manufacturing plastic end-use parts in a supply chain. Different AM technologies for plastic manufacturing are described and the main advantages and challenges are identified. Based on the company’s plastic part scope, a methodical framework for assessing parts regarding their AM suitability is established, in order to research the potential benefits of an AM implementation. The framework contains a methodical preselection and scoring process utilizing a top-down approach and an analytical hierarchical process (AHP), followed by a technical and economic assessment of the promising parts. In the research, only the existing design is taken into account: the same part, designed for conventional manufacturing technologies, is manufactured by AM without changes in geometry. Both cases, in-house manufacturing and purchasing from a service provider, were investigated with the employment of a cost model for FDM technology and a request for quotation from a general AM service provider. Both cases are compared to each other and the current conventional manufacturing technology.   It was found that, currently, utilizing an AM service provider is more beneficial for the company, due to the low number of parts that could be currently produced with AM. Hereby the lead time for AM profitable parts could be significantly reduced. Using AM, a centralized production with one AM service supplier is clearly seen as the preferable supply chain configuration in the case of the company.   The research provides guidance for the evaluation of part suitability concerning AM production of end-use plastic parts and contributes to the research concerning AM implementation in a supply chain in general and the aim of the company to acquire valuable AM knowhow in particular.<br>På sista tiden växer Additive Manufacturing (AM) snabbt och framläggar på grund av de framsteg som gjorts i hastighet, kvalitet, upplösning och performans. Följaktligen börjar AM, förutom prototypning, att blir viktigare för tillverkning av användningsdelar. Flera framgångsrika fallstudier rapporteras och företagen börjar undersöka möjligheterna att använda AM för produktionsprocesser och integrering pa supply chain.   Ändamål med denna forskning är att utvärdera potentialen att använda AM för tillverkning av plastdetaljer för slutanvändning i en supply chain. Olika AM-tekniker för plasttillverkning beskrivs och de viktigaste fördelarna och utmaningarna identifieras. På grundval av företagets plast delar omfång etableras en metodisk ram för bedömning av delar om deras AM-lämplighet för att undersöka de potentiella fördelarna med en AM implementering. Ramverket innehåller en metodisk förhandsval och poängprocess som utnyttjar en top-down-strategi och en analytisk hierarkisk process (AHP), följt av en teknisk och ekonomisk bedömning av de lovande delarna. I undersökningen beaktas endast den ekonomiska synvinkel: samma del, konstruerad för konventionell tillverkningsteknik, tillverkas av AM utan ändringar i geometri. Båda fallen, egen tillverkning och inköp från en tjänsteleverantör, undersöktes med anställning av en kostnadsmodell för FDM-teknik och en offertförfrågan från en allmän AM-tjänsteleverantör. Båda fallen jämförs med varandra och den nuvarande konventionella tillverkningstekniken.   Det konstaterades att det för närvarande är en AM-tjänsteleverantör som är mer fördelaktig för företaget på grund av det låga antal delar som kan för närvarande produceras med AM. Härav kan ledtiden för AM-lönsamma delar minskas betydligt. Med AM används en centraliserad produktion med en AM-tjänsteleverantör tydligt som den föredragna leveranskedjekonfigurationen när det gäller företaget.   Forskningen ger vägledning för utvärdering av delkompatibilitet avseende AM-produktion av plastdetaljer för slutanvändning och bidrar till forskningen om AM-genomförande i en supply chain i allmänhet och syftet med företaget att förvärva värdefullt AM-knowhow i synnerhet.

The thesis work is to show that the use of SLM (Additive Manufacturing) compared with the traditional process to make injection molds will have advantages in design, especially in waterways.  This thesis work gives seven different versions of design applied to the SLM method to analyze and compare them in Solidworks® and Moldflow® to figure out what design is suitable for the SLM method. Through analysis of different versions, the finding of this thesis work is that the conformal waterway of design and lighter but stead structure in the SLM method causes the SLM molds' cooling performance to be almost 15% better than the conventional way and shorten the production time by 18% per product. Based on the advantages of the SLM method in cooling system design and structure optimization, the company can use the SLM method in the production process to improve economic and environmental benefits.