GB/T 20793-2015Degummed ramie (English PDF)

Foreword

This standard was drafted in accordance with GB/T 1.1-2009 given rules. This standard replaces GB/T 20793-2006 "ramie crack Ma." This standard compared with GB/T 20793-2006, the main changes are as follows:

--- Increasing the terms and definitions in the chapter "lumps" in English equivalents;

--- Revised Table 3 part of the technical requirements, the value of a residual gum content increased from 2.00% to 2.50% relaxed, residual gum three Value from the original 5.00% to 4.50% tightened; upper limit of pH from 8 to 8.5, and the representation increased from 6 to

1 Scope

China's national product standard for degummed ramie - the cleaned bast fibre ready for spinning. It specifies the terms and definitions, the technical requirements, the sample size and sampling method, the test methods, the inspection rules, and the packaging, labelling, storage and transport, and it applies to the grading and classification of degummed ramie. Ramie is the strongest of the natural plant fibres and one of the oldest cultivated, and China grows nearly all of it. The fibre in the stem is bound together by an unusually large quantity of gum - pectins, hemicelluloses and lignin, up to a third of the raw fibre weight - and until that gum is removed the material cannot be spun at all. Degumming is therefore the central operation of the industry, done chemically with alkali under pressure and finished mechanically, and degummed ramie is what comes out of it: the point at which the crop becomes a textile raw material and the point at which it is traded. What a spinner needs to know about a lot is exactly what the degumming determined. The residual gum content decides whether the fibre will separate and spin. The fineness, expressed as linear density, decides the count that can be spun. The strength, the length and the soft handle determine the yarn quality, and the whiteness and the oil content determine the finishing. Excessive degumming damages the cellulose and costs strength; insufficient degumming leaves the fibre harsh and unspinnable. So the grades are built from those properties, and the standard fixes the sampling as carefully as the tests, because a bale of natural fibre is not uniform. Issued on 3 July 2015 and in force since 1 October 2015, it replaces GB/T 20793-2006.

This standard specifies the lean linen ramie terms and definitions, technical requirements, the number of samples, sampling methods, test methods, inspection rules, package Equipment, labeling, storage, transport. This standard applies to lean linen ramie grading and classification.

2 Normative references

The following documents for the application of this document is essential. For dated references, only the dated version suitable for use herein Member. For undated references, the latest edition (including any amendments) applies to this document.

GB/T 5881 Test Methods of sampling physical and chemical properties of ramie

GB/T 5882 Test method for breaking strength of ramie fiber bundle

GB/T 5884 Test Method for ramie fiber count

GB/T 5885 Test method for whiteness of ramie fiber

GB/T 5889 Ramie quantitative chemical composition analysis Determination of

GB/T 7573 Textiles pH value of the aqueous extract

GB/T 8170 repair value expressed about the rules and limit values \u200b\u200band judgment

GB/T 9995 Textile material moisture content and moisture determination oven drying method

3 Terms and Definitions

The following terms and definitions apply to this document.

3.1 After degummed ramie raw jute through.

3.2 Lumps lumpyramie Ma beam blocking a massive part.

3.3 Cooked underdegummed Ma beam partial degumming insufficient fiber.

3.4 Spot defects stain Ma beam wind rendered brown spots, spots, bug spots and other defects in general.

3.5 Rust ruststain Ma beam centralized or dispersed pollution rust on the fibers.

8 To

--- Modify the expression of all the formulas and symbols;

--- Increasing the pH value of the result of rounding provisions;

--- Appendix A modification of the original suspension last line segment into a separate article (now appendix A.3);

--- Added Appendix B (oil test method). This standard is proposed and managed by China Fiber Inspection Bureau. This standard was drafted. China Fiber Inspection Bureau, Hunan Provincial Fiber Inspection Bureau, Hunan Huasheng Group, Hunan star Ma Industry Co. Shares The company, Hubei Textile Co. essence. The main drafters of this standard. REGIONAL PLANNING, Jiang Min, Shen Pi Hua Xing high, Tang Wenfeng, Wantong spring. This standard replaces the standards previously issued as follows:

--- GB/T 20793-2006. Ramie crack Ma