NBN ISO 3387:2021

This document specifies a test based on hardness measurements for determining the progressive
stiffening of rubber with time, caused by crystallization. It is limited to materials having an initial
hardness at a test temperature of from 10 IRHD to 85 IRHD.
The method is applicable to raw, unvulcanized (compounded) and vulcanized rubber. It is mainly of
interest for rubber with a marked crystallization tendency at temperatures experienced in cold
climates, such as chloroprene and natural rubber.
The method is not applicable to fast-crystallizing materials which crystallize to a considerable degree
within the timespan of 15 min used for conditioning at test temperature.