ASTM D 1204 Test Method for Linear Dimensional Changes of Nonrigid Thermoplastic Sheeting or Film at Elevated Temperature / Testing Machine
8.2 Place the paper-plastic sandwiches horizontally in the oven at the temperature and for the length of time applicable to the material being tested. Sandwiches must not be stacked, as this may restrict movement of the plastic between the papers.8.3 At the end of the oven-exposure period, recondition the specimens a minimum of 1 h…