Rubber Retraction Test Fixture (ASTM D1329)

Model No. WTF-RR (Stainless Steel)

rubber retraction test fixture_0

Fig. 1: Assembled fixture without specimen installed.

ASTM D1329 (Reference 1) defines a temperature-retraction procedure for the rapid evaluation of crystallization effects and for comparing the viscoelastic properties of rubber and rubber-like materials at low temperatures. A small dog-boned specimen is held in an elongated condition, subjected to a low temperature, and then allowed to retract freely while raising the temperature at a uniform rate and measuring the retraction. The temperatures corresponding to 10 percent and 70 percent retraction are of particular interest.

The test fixture is shown in Fig 1, with several specimens of various lengths mounted and ready to be elongated. Additional specimens and end clamps are also shown. Standard specimens have gage lengths of 1 in., 1.5 in., or 2 in. The test fixture must be capable of applying up to 350 percent elongation, which accounts for its length. A scale on the side aids in measuring the initial elongation, and later the retraction.

Source of Additional Information:

1) ASTM Standard D1329-02 (2002), "Standard Test Method for Evaluating Rubber Property – Retraction at Lower Temperatures (TR Test)," American Society for Testing and Materials, West Conshohocken, Pennsylvania (originally published in 1954).