Every polymer supplier will provide you with a basic data sheet describing the properties of a particular grade. The good news is that each property value relates to a well understood, repeatable, reliable test related to international standards. Therefore, this makes comparison with other grades of similar plastics from a range of suppliers much easier.
Data Sheet – bad news
The bad news is that the standard test methods refer to a highly stylised test under a specific set of conditions (temperature, load, time, etc). Most likely these conditions do not correspond to the product service conditions you have in mind. As a result, materials data sheets are at best a snapshot of the potential of a particular grade. Very few of the values can be used directly by design engineers in their development calculations.
Data Sheet – good news
The good news is that most suppliers, on request or through websites such as UL IDES Prospector, or software such as Campus can provide additional and more relevant property data.
For calculations of mechanical functionality and also section thickness in a particular design, the modulus of rigidity data accessed from basic data sheets will refer to short term loading and low strain at room temperature. For load/deformation data over longer periods and higher strains, designers need to access creep data derived from measuring the change in dimensions under a range of loads and at different temperatures and humidity conditions. Such data may not be easy to come by or has to be generated at a significant cost.