GB flag iconENCN flag iconZH

Webinars and Online Resources

SATRA STD 401 Compression set apparatus

STD 401 Compression set apparatus image

Constant strain

This apparatus is designed for constant strain compression set testing of rubber and rubber-like materials at room temperature and elevated temperatures.

This is achieved by placing each of three discs between two compression plates screwed together until stopped by a distance piece. The apparatus consists of a stack of alternate compression plates and distance pieces allowing five rubbers to be tested at once. They are all compressed in one operation by turning a single hand nut on a centre bolt.

Test pieces are held compressed for the specified time and, after release and a short recovery period, the new thicknesses are measured. The compression set of the material is the amount of compression retained, expressed as a percentage of the original thickness of the disc.

To facilitate the hand tightening, the base of the apparatus is made to fit into a holder screwed to the bench, but it is easily removed from this if the apparatus needs to be placed in an oven for a high temperature test. Alternatively, the base of the instrument may be screwed to the bench if used for room temperature tests only.