GB/T 46471-2025Leather - Tests for colour fastness - General principles of testing (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 is modified to adopt ISO 7906:2022 "General rules for testing the color fastness of leather".

Compared with ISO 7906:2022, this document has undergone many structural adjustments. A comparison table of the structural numbering changes between the two documents can be found here.

Appendix A.

This document differs significantly from ISO 7906:2022.A single vertical line is drawn in the margin outside the relevant clauses.

(|) are marked. A summary of these technical differences and their causes can be found in Appendix B.

The following editorial changes have been made to this document.

---ISO 105-F10 (see 10.3.4) has been replaced by GB/T 7568.7 (reference standard).

---ISO 105-B01 (see 13.2) has been replaced by GB/T 8426, which is cited as informative reference.

---ISO 105-B02 (see 13.2) has been replaced by GB/T 8427, which is cited in the informational reference.

---ISO 105-B06 (see 13.2) has been replaced by GB/T 16991, which is cited as informative.

---The list of standards in informative Appendix C has been revised.

Please note that some content in this document may involve patents. The issuing organization of this document assumes no responsibility for identifying patents.

This document was proposed by the China National Light Industry Council.

This document is under the jurisdiction of the National Technical Committee on Standardization of Leather Industry (SAC/TC252).

1 Scope

This document defines the terminology and definitions related to leather color fastness testing and establishes the standards for color fastness testing methods (see Appendix C).

The general principles stipulate the general requirements for color fastness testing and reporting, the chapter contents constituting each test method, and establish the most test methods.

The general operating procedures are outlined, and an outline for drafting test method standards is provided.

This document applies to the assessment of colorfastness to leather, and also to the assessment of colorfastness to dyes on leather.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included.

For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies.

This document.

GB/T 250 Textiles - Tests for color fastness - Assessment of color change - Gray scale (GB/T 250-2008, ISO 105-A02.1993) IDT) GB/T 251 Textiles - Tests for color fastness - Assessment of staining - Gray scale (GB/T 251-2008, ISO 105-A03.1993) IDT) GB/T 6682 Specifications and test methods for water used in analytical laboratories (GB/T 6682-2008, ISO 3696:1987, MOD) GB/T 39364 Sampling sites for testing the chemical, physical, mechanical and color fastness of leather (GB/T 39364-2020, ISO 2418.

2017, MOD)

GB/T 39370 Physical and mechanical testing of leather - Determination of surface reflectivity (GB/T 39370-2020, ISO 17502.

2013, MOD)

GB/T 39376 Sampling quantity for leather (GB/T 39376-2020, ISO 2588:2014, MOD) QB/T 2262 Leather Industry Terminology QB/T 2707 Preparation and conditioning of test specimens for physical and mechanical testing of leather

3 Terms and Definitions

The terms and definitions defined in QB/T 2262 apply to this document.

4 Overview

The methods described in this document can be used to assess color changes and color migration in leather when exposed to chemicals, radiation, high temperatures, and weathering.

The staining of the lining material is expressed as color change grade and staining grade, respectively.

Colorfastness refers to the resistance of leather's color to various media it may come into contact with during processing and subsequent use. It is typically measured in leather samples.

The color change of the leather sample and the staining of the undyed lining fabric or other materials are used as the color fastness grade. In the test, the leather sample's...

Visible changes, such as appearance, gloss, or shrinkage, are described as separate characteristics in the test report.

When assessing the colorfastness of leather dyes, the dye is first applied to designated retanned leather or raw leather according to a prescribed procedure to achieve the specified color.

The color depth was determined, and then the dyed leather was tested using standard methods.