Commodity plastics thermal expansion

When materials with different coefficients of linear thermal expansion (CLTE) are bolted, riveted, bonded, crimped, pressed, welded, or fastened together by any method that prevents relative movement between the products, there is the potential for thermal stress. Most plastics, such as the unfilled commodity TPs, may have ten times the expansion rates of many nonplastic materials. However there are plastics with practically no expansion. Details are reviewed in Chapter 2, THERMAL EXPANSION AND CONTRACTION. 

The difference in thermal expansion between the usual commodity plastics and steel is very large. It is to be noted that some plastic material changes in length rather abruptly at some temperatures, beyond the limits of the test condition. In such cases, a special investigation should be instigated, and the coefficient of expansion established under temperatures of usage. However there are plastics that can be compounded to match or even have less thermal expansion than steel, etc. 

The thermal expansion of wood is less than that of the commodity plastics commonly used as matrices. Thermal expansion coefficients for wood are directional and are roughly [17]... 

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