Continuous compression moulding materials

A detailed analysis of the Raman spectrum of syndiotactic PS in the region 600-850/cm was undertaken. As syndiotactic PS exhibits considerable polymorphism, spectra of various preparations including melt-crystallised syndiotactic PS, solvent-crystallised syndiotactic PS and quenched glassy materials, were studied. Peaks are assigned to conformational changes and sequences. Comparison with atactic PS is made. Study of the cross section of a compression moulded plaque exhibiting a skin/core structure revealed the continuous way the structure varied with changing crystallinity. The various physical forms of syndiotactic... 

Compounds are short (/w 0.3 mm) or long (> 0.6 mm) fibre reinforced thermoplastic or thermoset polymeric materials, which are processed automatically (injection or compression moulding), have good (mechanical) properties (for automotive, electric and electronic applications) and are relatively cheap. Composites contain continuous fibres (rovings, fabrics or mats), usually combined with thermosets, have excellent mechanical (structural) properties, but are very expensive because lack of an industrial process (mainly used in aerospace and aircraft industry). 

Whilst only the author s private point of view, and one probably not shared by all others, it is expected that thermoplastic materials will gradually ease thermosetting materials, and consequently compression moulding, from their own specialised branches over the next decade. Requirements thereafter will be reduced, but certainly continue to exist and enough to supply the manufacturing capacity of most thermoset moulders for the foreseeable future. 

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