The Compressometer

Abstract

The instrument described in this paper provides a convenient means for measuring the thickness and the change in thickness of a textile or similar material when it is subjected to increasing or decreasing pressures. The foot of the instrument can be lowered or raised by means of a rack and pinion acting through a helical spring. The pressure applied to the specimen by the foot is indicated on a dial micrometer and the corresponding thickness of the specimen on a second dial micrometer. Readings are taken under increasing pressures and then under decreasing pressures. Curves for the compression and recovery of several materials are shown. Definitions are proposed for the terms thickness, compressibility and compressional resilience as applied to textiles. The results of tests on rug underlays, blankets, felts, on knit, woven, and pile fabrics and on sheet rubber and paper are given.