Giving sets plastic components

The thermoset component in polyurethanes gives them better compression set than most thermoplastic polymers. They also have better cold flow properties. Polyurethanes are tough and more resilient than a large number of other plastics. 

Fillers usually have a thermal conductivity about 20 times higher than plastics, and the specific heat is about 50%. By improving the heat transfer in the melt, the use of a filler may therefore give a faster set-up when moulding, and so improve the cycle time. In applications, the same effect may be useful in engineering components, improving heat dissipation and/or producing a thermal expansion closer to that of metal. 

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