There are two types of plastic tear strength test:
- Elmendorf Tear (high speed pendulum test)
- Trouser Tear (low speed using standard tensile test apparatus)
The test piece is clamped and a cut introduced such that when the pendulum is released, a tear is propagated from the cut at high speed. The tear resistance is measured as the average force in mN propagating the tear to the edge of the test piece.
Smithers Pira are UKAS accredited for testing to British standard BS 2782:3 method 360A.
Smithers Pira also test to International standard ISO 6383-2 and ASTM D1922.
A straight cut is introduced into a rectangular sample, parallel to the long edge. The sample is then mounted in the jaws of a tensile test apparatus, one "leg" clamped in the lower jaw and one "leg" clamped in the upper jaw. The average force required to tear the sample is measured.
Smithers Pira can test in accordance with British standard BS 2782:3 method 360B and BS 2782:3 method 360C, and DIN 53363.