ASTM D3787/D6797 - Bursting Strength
The ASTM Standard Test Methods D3787 (CRT) and ASTM D6797 (CRE) – Bursting Strength are used in order to evaluate the strength of knit textiles. This methodology evaluates the durability of knit textiles to determine their resistance to tearing under multidirectional force. The methods listed above apply the same testing practice but vary based on the machine used. CRT stands for Constant Rate of Traverse and CRE stands for constant rate of extension. Both machines are tensile testing machines but use different clamping mechanisms for sample mounting.
The test is performed on specimens conditioned in accordance with ASTM D1776. The specimen is placed in a ring-shaped clamp mounted in the machine. A polished steel ball is moved at a constant speed towards the secured specimen until the specimen is under enough stress, and bursts. The tensile tester records the force required to burst the specimen. To pass ANSI/ISEA 107, the minimum bursting strength shall be 267 N.