GB/T 40905.1-2021 in English

GB/T40905.1-2021 is the authoritative method standard for animal fiber testing in my country. It uses equipment such as projection microscope and microscopic image analyzer to achieve precise quantitative analysis through the morphological characteristics of the fiber surface. The standard is applicable to bulk fibers, yarns and various types of textile products.

1.

Three parallel samples need to be prepared, and each sample should test ≥1000 fibers:

• Bulk fiber: about 500 mg randomly sampled from 20 points
• Yarn: cut 0.6 mm fiber fragments
• Dark-colored samples need to be bleached according to Appendix B

2. Fiber Identification Characteristics

Main identification parameters:

• Cashmere: scale density 18-22 pieces/mm, circular arrangement
• Sheep wool: scale density 25-35 pieces/mm, tile arrangement
• Camel wool: oblique strip scale structure

Fiber mass percentage calculation formula:

w_i = [N_i(D_i²+S_i²)ρ_i] / Σ[N_i(D_i²+S_i²)ρ_i] ×100%

Wherein: D_i is the average diameter, S_i is the standard deviation, and ρ_i is shown in Appendix D Density Table

Key Points for Quality Control

• Regular use class=instrument>GSB022769 standard sampleCalibrate the instrument
• Cashmere with a diameter of ＞30μm is recorded as coarse hair
• Parallel sample results with a difference of ＞3% need to be retested

Handling of special cases

For variant fibers that are difficult to identify:

1. Pure cashmere samples are first identified as variant fibers
2. Blended samples are identified based on the majority of characteristics