Dimensional Stability ASTM D1204
Dimensional stability is an important property for many materials, especially sheeting and films made by extrusion or calendar processes. This property refers to the linear dimensional change that occurs when a material is exposed to a change in temperature. ASTM D1204 is a test method that is commonly used to measure dimensional stability.
The purpose of the test is to evaluate the lot-to-lot uniformity of the material and the internal stress that was introduced during processing. The test involves measuring the dimensions of the specimen at reference marks, sandwiching it between talc-dusted paper, and then exposing it to a specified temperature for a set amount of time. After removal from the oven, the specimen is reconditioned at room temperature for at least one hour before measuring the distance between the reference marks again.
The data obtained from the test is expressed as percent linear change, which is calculated by subtracting the final length from the original length, dividing it by the original length, and multiplying by 100. The resulting number gives an indication of how much the material has changed in size due to the temperature exposure.
Dimensional stability is an important property for materials used in a variety of applications. For example, in the packaging industry, dimensional stability is critical to ensure that the packaging maintains its shape and size during transportation and storage. In the construction industry, dimensional stability is important for materials used in building and infrastructure projects, where changes in temperature can cause warping or other structural problems. Overall, ASTM D1204 provides a reliable method for measuring dimensional stability and ensuring that materials meet the necessary quality standards.