Tensile testing of yarns is used to determine the breaking force, elongation, and toughness properties of the yarn. Breaking tenacity, a ratio of the breaking force to yarn linear density is also a common property for evaluating the strength of a yarn material and for comparison and validation purposes. Tensile testing of yarn to determine properties such as breaking strength and elongation includes the use of a tensile testing machine and unique grips to hold the yarn. It is necessary to clamp the yarn test specimen so that the machine loading access is aligned with the specimen axis. With a thin test specimen such as yarn, alignment of the specimen for tensile testing of yarn can prove difficult. This alignment of yarn during tensile tests is most easily achieved and repeatable using capstan style grips. Sharp edges on gripping devices can cause yarn specimen failure to occur outside the gage section and far below the actual tensile strength of the yarn. Early failure of yarn due to improper grips results in poor measurements of elongation rupture strain and breaking strength of yarn. Yarn capstan grips also help avoid this, as the yarn never encounters sharp edges. Capstan grips differ from wedge grips by distributing the tension in the yarn across a horn structure. ISO and ASTM Standard Tensile Test Methods of Yarn ASTM and ISO have standard test methods for testing the breaking strength, elongation, tenacity, modulus, and toughness of yarns. ASTM D2256 covers the standard test method for tensile testing single strand yarn. ISO 2062 also covers the test methods for tensile testing single strand yarn to determine tensile end break force and elongation. Yarn tension testing to determine tensile stress strain characteristics of yarn is typically conducted using low force, high elongation, constant rate of extension, table top tensile test machines. ASTM D76 and ISO 2062 specifies the requirements of the most widely used tensile test machines for textiles, including constant rate of extension (CRE), constant rate of force, and constant rate of loading (CRL) machines. The machine and grip families below meet ASTM and ISO requirements for tensile testing of yarns and can be configured to meet specific customer requirements.

Applicable Testing Standards

Recommended Test Machine