Sheet forming polymer matrix composites

Creasy T. Sheet forming in polymer matrix composites. In Advani S, Hsiao K-T, editors. Manufacturing techniques for polymer matrix composites (PMCs). Cambridge (UK) Woodhead Publishing Limited 2012. 

Sheet forming in polymer matrix composites 5.2.1 Physical processes during forming The physical processes that occur during sheet forming are ... 

Sheet forming in polymer matrix composites 129 Continuous fibre composites... 

The geometries for asymmetric mixed-matrix membranes include flat sheets, hollow fibers and thin-fihn composites. The flat sheet asymmetric mixed-matrix membranes are formed into spirally wound modules and the hollow fiber asymmetric mixed-matrix membranes are formed into hollow fiber modules. The thin-film composite mixed-matrix membranes can be fabricated into either spirally wound or hollow fiber modules. The thin-film composite geometry of mixed-matrix membranes enables selection of different membrane materials for the support layer and low-cost production of asymmetric mixed-matrix membranes utilizing a relatively high-cost zeolite/polymer separating layer on the support layer. 

Thermoplastic sheet forming is a thermal process and thermal conduction limits the production rate. Typical matrix polymers are poor conductors. Injection moulding and extrusion make polymer components affordable because they do not depend on conduction to provide all the heat needed to make a thermoplastic flow. Sheet forming, however, must bring a composite sheet to a uniform temperature and complete the forming process before any matrix - typically, the matrix at the surface because matrix there touches the cooler tool - becomes too rigid for forming. 

The idea of treating jute fibres with different additives to enhance the properties of hot-pressed Biopol composites was examined by Khan et al. (1999). As in a number of other research studies, Biopol , a PHBV originally developed by ICI but now owned by Metabolix Inc of the US, was the chosen polymer matrix. Jute was used in the form of a fabric combined with sheets of polymer film. Fibre treatments included 2-ethyl hexyl acrylate (3%), 7-methacryloxypropyltrimethoxysilane (2%) and trimethoxyvinylsilane (0.5%). These treatments were effective in improving composite mechanical properties by up to 80% over and above those properties obtained when using untreated fibre. 

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