1.1 ,This test method covers the determination of the coefficient of linear thermal expansion for plastic lumber and plastic lumber shapes to two significant figures. The determination is made by taking measurements with a caliper at three discrete temperatures. At the test temperatures and under the stresses imposed, the plastic lumber shall have a negligible creep or elastic strain rate, or both, insofar as these properties would significantly affect the accuracy of the measurements.
1.1.1 ,This test method details the determination of the linear coefficient of thermal expansion of plastic lumber and plastic lumber shapes in their “,as manufactured”, form. As such, this is a test method for evaluating the properties of plastic lumber or shapes as a product and not a material property test method.