GB/T 20392-2023Test method for physical properties of cotton fibers—High volume instruments method (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents" Drafting.

This document replaces GB/T 20392-2006 "HVI Cotton Fiber Physical Properties Test Method". Compared with GB/T 20392-2006, except In addition to structural adjustments and editorial changes, the main technical changes are as follows:

a) Changed the scope of application (see Chapter 1, Chapter 1 of the 2006 edition);

b) Added calibration level requirements for color standard cotton and color calibration porcelain plates (see 5.2);

c) The requirements for the graduation value of the balance have been changed (see 5.4, 5.4 of the 2006 edition);

d) Added calibration level requirements for micronaire calibration cotton (see 5.5);

e) Added the requirements for the length/strength calibrated cotton breaking ratio strength test distance level (see 5.6);

f) The standard atmosphere for humidity conditioning and testing has been changed (see 6.1, 6.1 of the 2006 edition), and the moisture regain conditions of pre-humidified samples have been changed (see 6.2, 6.2 of the 2006 edition), adds the requirements for sample equilibrium time in the dehumidified state (see 6.3);

g) Changed the quality requirements for laboratory samples (see 7.1, 2006 version of 7.1);

h) The sampling method has been changed (see 7.2, 2006 version of 7.2);

i) The quality requirements for test specimens have been changed (see 7.2, 8.1.2.1, 8.3.2.1, and 8.4.2.1 of the 2006 edition);

j) Changed the instrument warm-up time during color calibration (see 8.1.1.1, 2006 version of 8.1.1.1);

k) Added processing requirements when impurities, average length of the upper half and length uniformity verification are unacceptable (see 8.2.1.5, 8.4.1.6);

l) The requirements for micronaire calibration sample selection have been changed (see 8.3.1.1, 8.3.1.2 of the 2006 version), and the micronaire verification method has been added. method (see 8.3.1.4, 8.3.1.5), and the requirement for the number of micronaire tests (see 8.3.2.5) is added;

m) Changed the rules for numerical rounding (see 9.2, 9.1 of the 2006 version);

n) Added precision requirements for test methods (see Chapter 10);

o) Changed the content of the "Test Report" (see Chapter 11, Chapter 10 of the 2006 edition).

1 Scope

This document describes the large-capacity fiber tester that tests cotton fibers for color, impurities, micronaire, length and length uniformity index, and breakage. Specific strength and elongation at break methods.

This document is suitable for testing the physical properties of fine-staple cotton and long-staple cotton processed by top rollers or sawtooth.

2 Normative reference documents

The contents of the following documents constitute essential provisions of this document through normative references in the text. Among them, the dated quotations For undated referenced documents, only the version corresponding to that date applies to this document; for undated referenced documents, the latest version (including all amendments) applies to this document.

GB/T 6097 Cotton fiber test sampling method

GB/T 6529 Standard atmosphere for humidity conditioning and testing of textiles

GB/T 8170 Numerical rounding rules and expression and determination of limit values

3 Terms and definitions

The following terms and definitions apply to this document.