Speed of Retraction of Rubber

摘要

A method of measuring the speed of retraction of rubber is described which utilizes an electronic timing circuit with photo‐cell input. The results include measurements of the speed of retraction of Hevea and synthetic rubbers as a function of elongation, temperature, carbon black loading, and cure. They are discussed both from the standpoint of the new information which they give in regard to rubber structure and high elasticity as well as their practical application to evaluate quality and cure. High speed photographs are included which are of interest in showing the manner in which rubber retracts.