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The in-situ production of polyethylene fibres from polymer blendsSteadman, Stuart Charles January 1990 (has links)
No description available.
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Preferred fibre orientation in the injection moulding of polyester thermosetsGibson, John Robert January 1988 (has links)
No description available.
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Pultrusion of powder impregnated and commingled compositesMiller, Andrew Haydn January 1999 (has links)
No description available.
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Processing and characterization of long fiber thermoplasticsParthasarathy, Krishnan Balaji Thattai. January 2008 (has links) (PDF)
Thesis (Ph. D.)--University of Alabama at Birmingham, 2008. / Title from PDF title page (viewed Feb. 8, 2010). Additional advisors: J. Barry Andrews, Kathryn Brannon, Derrick R. Dean, Gregg M. Janowski, Mark L. Weaver. Includes bibliographical references (p. 158-161).
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Flammability evaluation of glass fiber reinforced polypropylene and polyethylene with montmorillonite nanoclay additivesVaddi, Satya. January 2008 (has links) (PDF)
Thesis (M.S.)--University of Alabama at Birmingham, 2008. / Title from PDF title page (viewed Feb. 1, 2010). Additional advisors: Derrick R. Dean, Gregg M. Janowski, Selvum (Brian) Pillay (ad hoc). Includes bibliographical references (p. 76-82).
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Enhanced adhesion performance of primer to thermoplastic olefins by low temperature cascade arc discharge plasmasLin, Yung-Sen, January 1996 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 201-208). Also available on the Internet.
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Enhanced adhesion performance of primer to thermoplastic olefins by low temperature cascade arc discharge plasmas /Lin, Yung-Sen, January 1996 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 201-208). Also available on the Internet.
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Application of commingled thermoplastic composites on an airline seat backrestMattheyse, Richard 12 1900 (has links)
Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: Thermoplastic composites (TPCs) have shown significant advantages over thermosetting
composites. They have only been put into use recently and global knowledge in TPCs is
often proprietary, therefore a study into the application, processing and properties is of
importance. The aim of the study is to contribute knowledge in TPCs for South African
industry and academic institutions.
This thesis studies continuous fibre reinforced thermoplastics (CFRTPs), focussing on the
autoclave processing of commingled CFRTPs. A literature study provided background
knowledge to CFRTPs regarding processing techniques and mechanics.
Flexural testing and impact testing were performed on a variety of CFRTPs and
thermosetting composites (TSCs). These tests were performed to further understand
CFRTPs as well as to compare CFRTPs and TSCs. The flexural testing revealed that
CFRTPs have comparable strength and stiffness to the TSCs that were tested. They also
revealed that pre-consolidated sheets showed better and more consistent properties than
sheets made from commingled fabric. The impact testing revealed that the tested CFRTPs
and TSCs had similar impact resistance even though thermoplastic composites are
supposed to be more impact resistant. The tests also showed that thick unreinforced
thermoplastics had much higher impact resistance than the reinforced materials.
Manufacturing experiments were performed to establish sound processing methods of
CFRTPs. It was realised here that the high temperatures required to process the materials
require specific processing consumables and tooling. The experiments began by
processing flat panels in a convection oven with vacuum bagging techniques. They then
progressed to autoclave processing of parts with complex geometry.
An airline seat backrest was chosen as the case study in the application of CFRTPs. This
application requires structural strength and stiffness and also has strict fire, smoke, toxicity
and heat release (FSTH) requirements. Its geometry was sufficiently complex to
demonstrate the use of commingled CFRTP material. Backrests were made from both
CFRTPs and TSCs so that a comparison could be made between the two types.
The backrest was modelled using finite element methods (FEM) to determine an adequate
lay-up. This lay-up was then used for both the CFRTP and TSC backrests to ensure
similarity between the backrests of both materials. LPET (modified polyethylene
terephthalate) was the chosen thermoplastic matrix as it was more attainable than PPS
(polyphenylene sulphide) CFRTPs. The backrests of both materials were manufactured in
an autoclave with a vacuum bag method and then assembled using adhesives and bonding
jigs. Testing revealed that the stiffness and mass of the CFRTP backrests were very similar
to the epoxy backrests. This implies that commingled CFRTPs can replace the use of
TSCs in similar applications.
A basic cost comparison was also performed to compare the manufacture of CFRTP
backrests to TSC backrests.
Further work is needed to optimise processing time of these materials to make them more
competitive with TSCs. The processing time of commingled materials will probably never
be as quick as that of press formed pre-consolidated sheets. Their ability to be formed into
more complex parts does however make their use advantageous. / AFRIKAANSE OPSOMMING: Termoplastiese saamgestelde materiale (Engels: thermoplastic composites (TPCs)) toon
beduidende voordele bo termoverhardbare saamgestelde materiale. Hulle word eers sedert
onlangs benut en algemene kennis in TPCs is dikwels patentregtelik, dus is ’n studie van
die aanwending, prosessering en eienskappe daarvan van belang. Die doel van hierdie
studie is om ’n bydrae te lewer tot die kennis van TPCs vir die Suid-Afrikaanse industrie
en akademiese instellings.
Hierdie tesis ondersoek kontinue veselversterkte termoplastieke (Engels: continuous fibre
reinforced thermoplastics (CFRTPs)) en fokus op die outoklaafprosessering van vermengde
(Engels: commingled) CFRTPs. ’n Literatuurstudie het die agtergrondkennis rakende die
prosesseringstegnieke en meganika van CFRTPs verskaf.
Buigtoetsing en impaktoetsing is op ’n verskeidenheid CFRTPs en termoverhardbare
saamgestelde materiale (Engels: thermosetting composites (TSCs)) uitgevoer. Hierdie
toetse is uitgevoer om CFRTPs beter te verstaan asook om CFRTPs en TSCs te vergelyk.
Die buigtoetsing het onthul dat CFRTPs ooreenstemmende sterkte en styfheid het as die
TSCs wat getoets is. Dit het ook getoon dat vooraf-gekonsolideerde plate beter en meer
konsekwente eienskappe getoon het as plate wat van vermengde materiaal gemaak is. Die
impaktoetsing het onthul dat die CFRTPs en TSCs wat getoets is soortgelyke
impakweerstand gehad het, selfs al is termoplastiese saamgestelde materiale veronderstel
om meer impakweerstand te toon. Die toetse het ook getoon dat dik onversterkte
termoplastieke veel hoër impakweerstand gehad het as die versterkte materiale.
Vervaardigingseksperimente is uitgevoer om betroubare prosesseringsmetodes vir CFRTPs
vas te stel. Daar is besef dat die hoër temperature wat vereis word om die materiale te
prosesseer ook spesifieke prosesseringsverbruiksware en -gereedskap benodig. Die
eksperimente het begin met die prosessering van reguit panele in ’n konveksie-oond met
vakuumsaktegnieke. Daar is toe aanbeweeg na die outoklaafprosessering van onderdele
met komplekse geometrie.
Die rugleuning van ’n vliegtuigsitplek is gekies as die gevallestudie in die gebruik van
CFRTPs. Hierdie toepassing vereis strukturele sterkte en styfheid en is ook onderhewig
aan streng vereistes t.o.v. brand, rook, toksisiteit en hittevrystellimg (Engels FSTH). Die
geometrie daarvan was kompleks genoeg om die gebruik van vermengde CFRTP-materiaal
te demonstreer. Rugleunings is gemaak van beide CFRTPs en TSCs sodat ’n vergelyking
tussen die twee tipes gemaak kon word.
Die rugleuning is gemodelleer deur eindige element metodes (EEM) te gebruik om ’n
aanvaarbare oplegging te bepaal. Hierdie oplegging is toe gebruik vir beide die CFRTP en
TSC rugleunings om die gelykvormigheid tussen die rugleunings van beide materiale te
verseker. LPET (Engels: modified polyethylene terephthalate) was die gekose
termoplastiese matriks aangesien dit meer verkrygbaar was as PPS (Engels: polyphenylene
sulphide) CFRTPs. Die rugleunings van beide materiale is vervaardig in ’n outoklaaf met
’n vakuumsakmetode en toe geintegreer deur die gebruik van kleefstowwe en setmate.
Toetsing het getoon dat die styfheid en massa van die CFRTP rugleunings baie soortgelyk
was aan die epoksie rugleunings. Dit impliseer dat vermengde CFRTP die plek van TSCs
in soortgelyke gebruike kan inneem.
’n Basiese kostevergelyking is ook gedoen om die vervaardiging van CFRTP-rugleunings
teenoor TSC-rugleunings te vergelyk.
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Technical Analysis of Flax Fiber Reinforced Polypropylene : Prerequisites for Processing and Recycling / Teknisk analys av linfiber förstärkt polypropen : Förutsättningar för bearbetning och återvinningMattsson, Josephie January 2014 (has links)
Nowadays, when environmental concerns are becoming increasingly important are there great interest in natural materials and recyclability. The possibility of reusing materials with maintained mechanical properties are essential for sustainability. Today produced approximately 90,000 tons of natural fiber reinforced composites in Europe of those are 40,000 tons compression molded of which the automotive industry uses 95%. Natural fiber reinforced composites is recyclable and therefore interesting in many applications. Also, natural fiber reinforced composites is inexpensive, light in weight and shows decent mechanical properties which makes them attractive to manufactures. However, the problem with natural fiber reinforced composites is the poor adhesion between fiber and matrix, the sensitivity of humidity and their low thermal stability. Those problems could be overcome by addition of compatibilizer and reactive filler. This study will examine the technical requirement in order to develop a sustainable and recyclable biocomposite. It investigates the composition of matrix (polypropylene), fiber (flax), compatibilizer (maleic anhydride grafted polypropylene) and reactive filler (CaO) in order to obtain various combinations of stiffness, strength and processability. The two main methods used for preparing samples were compounding and injection molding. Results shows that 20 wt% flax was the optimal fiber content and that maleic anhydride grafted polypropylene is a very good compatibilizer by enhancing the strength significant. Surprisingly was the strength impaired due to the addition of CaO. The composition of 20 wt% flax, 1 wt% maleic anhydride grafted polypropylene and 79 wt% polypropylene is the technically most favorable composition.
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Caractérisation thermomécanique du comportement en fatigue des thermoplastiques renforcés de fibres de verre courtes / Thermomechanical characterization of the fatigue behaviour of short fibers reinforced thermoplasticSerrano Abello, Leonell 03 November 2015 (has links)
L’allégement des véhicules est une préoccupation majeure de l’industrie automobile, puisque cela permet de réduire les émissions des gaz à effet de serre, ce qui entraînerait une réduction des impacts de ceux-ci sur l’environnement à l’échelle mondiale. Cette volonté d’allégement des véhicules tout en restant accessible en termes de coûts, a conduit au remplacement des matériaux métalliques par des composites à matrices thermoplastiques pour de nombreuses applications. Le compromis entre la tenue thermomécanique et le coût massique du matériau amène à sélectionner des matrices polyamides renforcées par des fibres de verre courtes, et mises en forme par injection. Cependant, les outils prédictifs du comportement et les critères robustes pour la caractérisation des propriétés en fatigue, manquent encore. Ils sont pourtant indispensables pour la conception de pièces structurelles dans l’industrie automobile. La caractérisation en fatigue des polyamides renforcés de fibres de verre courtes présente de nombreuses difficultés, liées au comportement fortement non linéaire de la matrice dans les conditions de service visées (température et humidité), à la nature composite de ces matériaux, à l’influence du procédé de fabrication (orientation des fibres) et au caractère fortement dissipatif de la matrice thermoplastique (augmentations de température non négligeables lors des chargements cycliques). Un enjeu majeur est de comprendre les liens entre la microstructure, le chargement thermo-(hygro)-mécanique et les propriétés de fatigue (sites d’initiation, scénarios d’évolution, critère de rupture). Le premier objectif de cette thèse est de proposer des protocoles d’analyse permettant de caractériser l’influence de chaque paramètre sur le comportement en fatigue. Par ailleurs, la complexité des pièces industrielles en termes de géométrie et d’orientation des fibres soulève la question de la pertinence des éprouvettes classiques. Le second objectif principal de cette thèse est donc de concevoir des éprouvettes représentatives en terme d’orientation des fibres et d’accidents géométriques des pièces industrielles (appelées éprouvettes de structure) et de valider pour ces cas complexes, les démarches et critères proposés. Pour répondre à ces objectifs, nous souhaitons proposer un protocole basé sur des mesures d’auto-échauffement, qui donnerait accès d’une part aux champs d’énergie dissipée pour les cas hétérogènes investigués et qui offrirait, d’autre part, une opportunité de caractérisation rapide des propriétés en fatigue au travers de critères énergétiques / Vehicle weight reduction is a major issue in the automotive industry, because this contributes to reducing global warming emissions, resulting in a reduction of negative environmental impacts at the worldwide scale. To replace heavy metallic materials conventionally used, short fiber reinforced thermoplastics (SFRT) provide today a major opportunity to obtain lightweight automotive parts at a reasonable cost for several applications. The cost and the thermomechanical properties motivate the choice of polyamide matrix reinforced with glass fibers manufactured by injection molding. However, predictive modeling behavior tools and robust fatigue criteria must be identified. Both are needed for the design of structural pieces in the automotive industry. The fatigue design of SFRT components for structural applications in the automotive industry requires an accurate knowledge of several factors because the material features are complex, these features are related to the strong nonlinear behavior of the matrix under the service conditions (temperature and humidity), the composite nature of the material, the influence of the injection molding (fiber orientation) and the dissipative characteristics of the thermoplastic matrix (significant temperature rise during the cyclic loadings). A major issue is to understand the relations between the microstructure, the thermo-hydro-mechanical loading and the fatigue properties (fatigue initiation sites, evolution scenarios, and failure criterion). The first objective of this thesis is to suggest methods that allow for the characterization of the influence of each parameter on the fatigue behavior. Furthermore, the complexity of the industrial pieces in terms of geometry and fiber orientation challenges the relevancy of the classical samples. The second objective of this thesis is consequently to design more complex samples that intend to be representative in terms of fiber orientation and geometric details found in the industrial pieces (called structural samples) and to validate the methods and the fatigue criteria suggested for these complex cases. To achieve these objectives, a method based on thermal measurements giving access to the dissipation fields for the heterogeneous cases considered is proposed, this method also offers a very high reduction of the characterization duration of the fatigue properties through energetic criteria
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