Elmendorf Tear Strength - ASTM D1922
The average force required to propagate tearing through a specified length of plastic film or nonrigid sheeting on an Elmendorf-type tear tester.
Constant Radius Specimen
Constant radius specimens are used for materials that do not tear in a straight line.
Test specimens have a pre-cut slit. Testing is performed using a knife-tipped pendulum. The average force is calculated from the pendulum energy lost while tearing the test specimen. Tear direction is either in the machine direction (MD) or transverse direction (TD).