Thermal conductivity plastics

Plastics are susceptible to brittle crack-growth fractures as a result of cyclic stresses in much the same way as metals. In addition, because of their high damping and low thermal conductivity, plastics are prone to thermal softening if the cyclic stress or cyclic rate is high. Examples of the TPs with the best fatigue resistance include PP and ethylene-propylene copolymers. 

Thermal conductivities of plastics are relatively low and approximate 0.0004 (cal-cm)/(°C-cm -sec). The corresponding values are 0.95 for copper, 0.12 for cast iron, 0.002 for asbestos, 0.0008 for wood, and 0.0001 for cork (SI values in J/s-m-k are obtained by multiplying by 418.7). Because of their low thermal conductivities, plastics are used for handles to cooking utensils and for automobile steering wheels. The low thermal conductivity is also responsible for the pleasant feel of plastic parts. Quite hot or quite cold objects can be handled with less difficulty if they are made of plastic, since the thermal insulation afforded by the plastic prevents a continuous rush of heat energy to (or from) the hand. 

Hardness/abrasiveness Friability GrindabiUty Dustiness index Thermal properties Calorific value Heat capacity Thermal conductivity Plastic/agglutinating Agglomerating index Free swelling index... 

High-thermal-conductivity plastics are those that have been formulated to provide higher thermal conductivity while maintaining good electrical insulating... 

J. Ogando, Thermally conductive plastics beat the heat. Design News, September 17,... 

Low thermal conductivity - Plastic parts cool slowly, restricting the thieknesses that can be molded and requiring the part be left in the mold a relatively long time before it can be demolded without warping. 

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