GB/T 19975-2005Test method of tensile properties for high tenacity filament yarn (English PDF)

1 Scope

This standard specifies the test methods for breaking strength, elongation at break, initial modulus and tensile creep properties of high tenacity filament yarn.

This standard is applicable to ultra-high molecular weight polyethylene fiber, aromatic polyamide fiber (aramid fiber), carbon fiber and other high tenacity filament yarns (generally refer to filament yarns with breaking strength greater than 10 cN/dtex).

The test method for tensile creep properties in this standard is not applicable to the filament yarns whose elongation changes by more than 5% when a load of 1 cN/dtex is applied for 1 min.

2 Normative references

The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections) to, or revisions, of any of these publications do not apply to this standard. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition applies.

GB/T 3291.1 Textiles—Terms of textile material properties and test—Part 1: Fibre and yarn

GB/T 3291.3 Textiles—Terms of textile material properties and test—Part 3: General

GB/T 4146 Textile terms and terminology (parts of chemical fibers)

GB/T 6502 Sampling method for synthetic filament yarns

GB 6529 Textiles—Standard atmospheres for conditioning and testing

GB/T 8170 Rules for rounding off of numerical values

GB/T 14343 Testing method for linear density of synthetic filament yarns and textured yarns

3 Terms and definitions

For the purposes of this standard, the terms and definitions given in GB/T 3291.1, GB/T 3291.3 and GB/T 4146 as well as the following apply.

4 Principle

Breaking strength and initial modulus: The specimen is stretched until it breaks, and the breaking force and elongation are obtained, and the breaking strength is calculated using the breaking force and linear density; the slope of the tangent line of the initial part near the straight line on the stress-strain (force-elongation) curve is obtained, and the initial modulus is calculated using the slope and linear density.

Tensile creep: Pre-tension is applied to the specimen to obtain the initial length, and then a certain load is applied for a certain time (or until the specimen length remains unchanged), and the specimen length is measured again to calculate the difference between the two lengths (i.e. creep elongation) and the percentage of the initial length, i.e. tensile creep elongation.

5 Test apparatus