Compression moulding polymer matrix composites

Bickerton S, Kelly P. Compression resin transfer moulding (CRTM) in polymer matrix composites. In Advani S, Hsiao K-T, editors. Manufacturing techniques for polymer matrix composites (PMCs). Cambridge (UK) Woodhead Publishing Limited 2012. 

Compression resin transfer moulding (CRTM) in polymer matrix composites... 

Both thermoplastics and thermosets can be formed by compression moulding (Fig. 24.5). The polymer, or mixture of resin and hardener, is heated and compressed between dies. The method is well suited to the forming of thermosets (casings for appliances, for instance) and of composites with a thermosetting matrix (car bumpers, for example). Since a thermoset can be removed while it is still hot, the cycle time is as short as 10 seconds for small components, 10 minutes for large tliick-walled mouldings. Pressures are lower than for injection mouldings, so the capital cost of the equipment is much less. 

A significant amount of waste composites is generated each year and the need for a recycling method is becoming a necessity. Environmental Technical Services has developed, with the support of the University of Missouri-St.Louis, a method for recovering valuable constituents from composite materials. The process converts the polymer matrix to lower chain hydrocarbons and fuel gas leaving behind fibres. Mechanical tests of BMC panels, reinforced concrete and compression moulded panels made with recovered fibres were carried out. 10 refs. USA... 

These polymers can be moulded by injection or compression and can be cast as films fi om organic solvents. Their isotropic tensile moduli are well beyond the range of known isotropic polymers. They have outstanding mechanical properties, considerably better than those of the best polymeric materials, and can even be compared to structural metals [66] (see Mechanical properties). The rigid PPP backbone is presented as the microscopic equivalent of the fibre in a fibre-polymer composite, such as oriented carbon fibres embedded in a suitable polymer matrix the pendant groups play the role of the suitable polymer matrix. Applications in the design and construction of military and commercial aircraft, sports and industrial equipment and automobile components are proposed. 

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