ISO 815-1:2019
Rubber, vulcanized or thermoplastic — Determination of compression set — Part 1: At ambient or elevated temperatures

Standard No.

ISO 815-1:2019

Release Date

2019

Published By

International Organization for Standardization (ISO)

Latest

ISO 815-1:2019

Scope

This document specifies methods for the determination of the compression set characteristics of vulcanized and thermoplastic rubbers at ambient (one method) or elevated temperatures (three methods, A, B, and C, depending on the way the test piece is released at the end of the test). The methods are intended to measure the ability of rubbers of hardness within the range 10 IRHD to 95 IRHD to retain their elastic properties at specified temperatures after prolonged compression at constant strain (normally 25 %) under one of the alternative sets of conditions described. For rubber of nominal hardness 80 IRHD and above, a lower compression strain is used: 15 % for a nominal hardness from 80 IRHD to 89 IRHD and 10 % for a nominal hardness from 90 IRHD to 95 IRHD. NOTE 1 When rubber is held under compression, physical or chemical changes that prevent the rubber returning to its original dimensions after release of the deforming force can occur. The result is a set, the magnitude of which depends on the time and temperature of compression as well as on the time, temperature, and conditions of recovery. At elevated temperatures, chemical changes become increasingly more important and lead to a permanent set. NOTE 2 Short-time compression set tests, typically for 24 h, at elevated temperatures are commonly used as a measure of the state of cure, a means of material classification, and a specification to ensure the quality of a compound. Longer tests, typically for 1000 h, at elevated temperatures take account of the effect of ageing and are often used to predict service performance, including that of sealing materials. Short-time tests at ambient temperature show mainly the effect of physical changes (re-orientation of the molecular chains and the fillers).

ISO 815-1:2019 Referenced Document

• ISO 18899:2013 Rubber - Guide to the calibration of test equipment
• ISO 188:2011 Rubber, vulcanized or thermoplastic - Accelerated ageing and heat resistance tests
• ISO 23529:2016 Rubber - General procedures for preparing and conditioning test pieces for physical test methods

ISO 815-1:2019 history

• 2019 ISO 815-1:2019 Rubber, vulcanized or thermoplastic — Determination of compression set — Part 1: At ambient or elevated temperatures
• 2014 ISO 815-1:2014 Rubber, vulcanized or thermoplastic - Determination of compression set - Part 1: At ambient or elevated temperatures
• 2008 ISO 815-1:2008 Rubber, vulcanized or thermoplastic - Determination of compression set - Part 1: At ambient or elevated temperatures