Polyester Moulding Research Articles

Ruminant Ön Bacağında Anatomik Modellerin Oluşturulması

The veterinary anatomy education is taught as two phased, which are theoretical and practical education in Turkey. While in theoretical class a didactical instruction is presented, in practical class the learning process is consolidated by using mockup, model and cadaver. Nevertheless at the present time the mockups which are provided by commercially are prepared insufficiently as class materials. Therefore with this study, it was determined to create ruminant forelimb bone-joint-muscle-nerve models which are supported academically. For bone modelling 80 pieces of rectangular parallelepiped were prepared by using approximately 100 kg of clay, then by using carbon paper schemas were drawn on them. For polyester moulding bone modelling, by taking silicon pattern from the prepared model and reproducing with polyester moulding the mockups were made. The polyester models which were prepared for joint modeling were put together with steel construction as (to be) movable. During the process of muscle-modeling, colorful eva paper is used. For the nerve-modeling, forelimb nerves were placed on the main model which had been made before. Thus new alternative models were created for the purpose of education of veterinary anatomy. We are of the opinion that outcomes obtained from the study will give a different point of view in training process in veterinary faculties.

Deformation, Strength Properties and Crack Resistance of Short-Fibre Polyester Moulding Compositions (Premixes) in Tension and Bending

Deformation, Strength Properties and Crack Resistance of Short-Fibre Polyester Moulding Compositions (Premixes) in Tension and Bending

Polyester moulding compounds of natural fibres and wollastonite

Abstract Combination of natural fibres and wollastonite whiskers has been attempted as an alternative to glass fibre reinforcement in polyester dough moulding compounds. Natural fibres (sisal) and wollastonite were surface-modified with polyester compatible neo pentyl (diallyl) oxy, tri (dioctyl) pyro-phosphato titanate and gamma-methacryloxy propyl trimethoxy silane coupling agents, respectively. Reinforcing effect of wollastonite to a level of ∼50 wt% in an unsaturated polyester resin reveals a positive indication because of its favourable physico-mechanical properties and microstructural features. The optimization of short sisal and glass fibres in wollastonite/polyester system was carried out to formulate a doughy compound. It was found that ∼11 wt% sisal fibres in wollastonite/polyester and ∼3 to 5 wt% glass fibres in sisal/wollastonite/polyester give the optimum results. The high loss area observed at α and β transitions in dynamic mechanical analyser (DMA) traces supported the elastic behaviour of sisal/wollastonite/polyester moulding compared to corresponding wollastonite/polyester system. Based on these findings, a dough composition has been formulated and its suitability was assessed vis-a-vis to glass fibre–dough moulding compounds. It is observed that polyester dough moulding compound prepared from sisal/wollastonite reinforcement gives satisfactory results.

US 5,032,631 UV stabilized polyester moulding compounds

Immunotoxicity, defined as adverse effects of xenobiotics on the immune system, is gaining increasing attention in the approval process of industrial chemicals and drugs. In-vivo and ex-vivo experiments have been the gold standard in immunotoxicity assessment so far, so the development of in-vitro and in-silico alternatives is an important issue.In this paper we describe a widely applicable, easy-to use computational approach which can serve as an initial immunotoxicity screen of new chemical entities. Molecular fingerprints describing chemical structure were used as parameters in a machine-learning approach based on the Naïve-Bayes learning algorithm.The model was trained using blood-cell growth inhibition data from the NCI database and validated externally with several in-house and literature-derived data sets tested in cytotoxicity assays on different types on immune cells. Both cross-validations and external validations resulted in areas under the receiver operator curves (ROC/AUC) of 75% or higher.The classification of the validation data sets occurred with excellent specificities and fair to excellent selectivities, depending on the data set. This means that the probability of actual immunotoxicity is very high for compounds classified as immunotoxic, while the fraction of false negative predictions might vary. Thus, in a multistep immunotoxicity screening scheme, the classification as immunotoxic can be accepted without additional confirmation, while compounds classified as not immunotoxic will have to be subjected to further investigation.

Polyester moulding compounds with novel initial fibre orientation for use in injection moulding

This paper describes a systematic study of the effect of initial fibre orientation on the flexural and impact strength of injection moulded thermosetting polyester moulding compounds. A range of special compounds was prepared, with three different types of initial fibre orientation: fully random (3-D), random-in-plane (2-D) and unidirectional (1-D). It was found possible to produce injection mouldings with low levels of fibre breakage and significantly improved properties by using starting compounds with either 2-D or 1-D fibre orientation. This does not appear to be possible with 3-D compounds, such as dough moulding compounds. In addition to using a starting material with preferred fibre orientation, it is also desirable that the matrix viscosity under processing conditions be as low as possible. In the case of sheet moulding compounds, ‘physically thickened’ compounds give better performance than MgO-thickened materials for this reason. Comparisons between the behaviour of dough moulding compounds and that of compounds made by the continuous impregnation method confirm the findings of other workers, that the latter technique is capable of producing compounds with a much lower level of initial fibre degradation.

US 4,851,467 polyester moulding composition containing carbon black

The interaction mechanisms of the cement paste hydration products with chloride were investigated for various systems. Test parameters included water/binder ratio (0.25 and 0.45), type of cement (ASTM type I, III, and V), use of silica fume (6%), and chemical composition of the chloride solution. Powdered cement paste samples were immersed in solutions of different chloride concentrations. The total amount of bound chlorides was determined by measuring the equilibrium chloride concentration of the solution after 3 weeks of immersion. The chemical interaction of chlorides with the hydrated cement paste was also studied by X-ray diffratometry. Test results show that the total amount of bound chlorides increases with the chloride concentration of the solution. This nonlinear relationship can be represented best by a Freundlich isotherm. When expressed on a unit mass of cement gel basis, the total amount of bound chlorides was found to be independent of the water/binder ratio and the type of binder in all cases but one. The chloride binding capacity and the formation of chloroaluminates appear to be attributable not only to the tricalcium aluminate content but also to the total aluminate content of the cement. The use of calcium chloride instead of sodium chloride, as well as the use of a lime solution instead of an alkaline solution, increases the amount of bound chlorides.

Reinforced polyester moulding materials - development trends and actual situation in Poland

Reinforced polyester moulding materials - development trends and actual situation in Poland

Cracking in bolted SMC components

Recent developments in the substitution of plastics for metal components have led to a requirement for further information on the applicability of existing mechanical fastenings to these newer materials. The generic group of glass reinforced thermoset plastics known as ‘polyester moulding compounds’ has been found to be suitable for many replacement components, particularly in the automotive industry, but these materials are subject to cracking under certain loading conditions. The present work uses a simulated bolt loading technique to relate material thickness, bolt diameter, and support configuration to a limiting sustainable load. Acoustic emission methods are also used to relate the onset of cracking to the support conditions and the ultimate load. The conclusions suggest that, for the material studied, positioning of the fixing hole at least two hole diameters from the material edge and use of a material thickness/bolt diameter ratio ≥3, should result in the equivalent mild steel bolt failing before cracking is initiated or ultimate composite failure occurs.

Polyester moulding materials in automotive underbonnet environments

This paper describes investigations which have been carried out to characterize the behaviour of polyester moulding compounds when subjected to tests in environments encountered in automobile underbonnet situations. The tests contrast the behaviour of various polyester resin types in aqueous and hydrocarbon media; and show that the materials which best resist water and antifreeze exhibit the greatest degradation in petrol. The resistance of a range of polyester types to dry heat at 130°C and 180°C is discussed. Combinations of resin and glass fibre types have been tested in boiling water: the results show that the correct choice of resin and glass fibre can improve the onset of blistering from within one week to over 12 months. Single surface exposure of moulded plaques is shown to result in a far higher level of strength retention than total immersion of the material. A comparison has been made of the effect of different types of motor fuel, including methanol additives and ethanol, on the strength retention of dough moulding compound and sheet moulding compound throughout a 12 month ageing period.

Injection moulding of polyester moulding compounds

Injection moulding of polyester moulding compounds

Glass-fibre-reinforced flame-resistant thermoplastic polyester moulding compositions containing Poly (2, 4, 6-Tribromostyrene): Buxbaum, L., and Breitenfellner, F. (Ciba-Geigy Corporation) US Pat 3 975 354 (17 August 1976)

Glass-fibre-reinforced flame-resistant thermoplastic polyester moulding compositions containing Poly (2, 4, 6-Tribromostyrene): Buxbaum, L., and Breitenfellner, F. (Ciba-Geigy Corporation) US Pat 3 975 354 (17 August 1976)

Cyclic loading and the strength of dough moulding compounds

The response of polyester moulding compounds (dmc) to cyclic tensile loading has been studied by determining the residual tensile strength as a function of number of reversals. The effects of stress concentrations and exposure to hot water on this response are also discussed. It is found that there are two separate régimes of behaviour identified by the position of a change in the elastic slope of the stress/strain curve — the ‘knee’ — a point also indicated by a substantial increase in acoustic activity monitored by stress wave emission techniques. When the cyclic load level is above this knee the behaviour of dmc resembles that of ordinary glass-reinforced plastics (grp), but below this level dmc appear to be rather less sensitive to fatigue.

Influence of pressure in processing polyester moulding compounds : Moseler, H. J. Kunstoffe Vol 64 (May 1974) p 234

Influence of pressure in processing polyester moulding compounds : Moseler, H. J. Kunstoffe Vol 64 (May 1974) p 234

USA Specifications for composites: (3) ASTM standards for polyester and epoxide resin systems

ASTM standards are confined to a grading system for epoxide resins and a specification for filled polyester moulding materials.