Requirements for physical testing of rubbers and plastics

This introductory paper reviews in a general way the requirements for physical testing of rubbers and plastics. The perennial questions of why and how we test are raised and considered with reference to product examples. A grouping of physical tests is suggested based on the use and value of the information they provide and related to the reasons for testing. Particular attention is given to the role of standards and to the sometimes conflicting requirements of quality control and design.