Tensile testing, plastics standard impact tests

When use conditions differ from those applied to data sheet tests, certain comparative evaluation can be made. Selecting an established high impact plastic such as polycarbonate as the standard, a tensile test would be made on this material at use speeds of strik-... 

ASTM D 1822-89 Standard Test Method for Tensile-Impact Energy to Break Plastics and Electrical Insulating Materials, 9 pp (Comm D-20) There is a metric version, ASTM D 1822M-89... 

Standard test method for tensile-impact energy to break plastics and electrical insulating materials. 

In the past, results of standard tests such as tensile strength, Izod impact strength, and softening point have been given major emphasis in plastic technical literature. More recently, however, with the increasing use of plastics in more critical applications, there has been a growing awareness of the need to supplement such information with data collated from tests more closely simulating operational conditions. 

Manufacturers handbooks give data on tensile and flexural yield or fracture stress, tensile elongation at break, notched Charpy or Izod impact strength, and fatigue life. Whilst these data are useful for materials selection, they are not always sufficient for quantitative design. To date, fracture mechanics has been used to only a limited extent in design with plastics, and data are not provided in data books. The lack of approved standards for testing of polymers is currently a major obstacle to the wider use of fracture mechanics. 

Standard Test Method for Tensile-Impact Energy to Break Plastics and Electrical Insulating Materials... 

A true material comparison is possible only when property values are determined by identical test methods under identical conditions (1). Generally speaking, physical and electrical properties of plastics and electrical insulating materials are affected by temperature and humidity. Plastic materials tested above room temperature will yield relatively higher impact strength and lower tensile strength and modulus. High humidity tends to alter the electrical property test results. Obviously, in order to make reliable comparisons of different materials and test results obtained by different laboratories, it is necessary to establish standard conditions of temperature and humidity. 

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