GB/T 1797-2008Raw silk (English PDF)

Foreword

This standard replaces GB 1797-2001 "silk." This standard compared with GB 1797-2001 The main changes are as follows:

--- Standard mandatory nature of the change recommended;

--- Adjust the level range of raw silk;

--- Adjust the fineness of silk deviation, maximum deviation fineness, even the second time change, even change three times, cutting, breaking strength, elongation at break Content, cohesion and other indicators of the level of technical quality;

--- Increased 80 points and the following appears clean sheet silk yarn batch, the final rating can not be set at a predetermined level 6A;

--- Adjust the appearance of defects in raw silk twisted uneven weight standard value;

--- Added "silk gum content" select test items;

--- Adjust the relevant provisions of the packaging and labeling of raw silk. The standard proposed by China Textile Industry Association. This standard by the National Standardization Technical Committee silk textile branch. This standard is drafted by: Zhejiang Cathaya International Co., Ltd., Zhejiang Silk Technology Co., Ltd., Zhejiang Entry-Exit Inspection and Quarantine Bureau, Guangdong Silk Textile Group Co., Ltd., Rizhao Haitong Silk Group Co., Ltd. Xinyuan Silk Group Co., Ltd., Anhui source licensing Kong (Holdings) Co., Ltd., China silk trading market. The main drafters of this standard. Bian fortunate children, Zhou Ying, Xu Jin, Lu Xing, Chen Nansheng, An Xia, Qian Ying Hua, Wang Haitao, Chen Jinming, Weijun Ling, Xu Qin. This standard replaces the standards previously issued as follows:

--- GB 1797-1979, GB 1799-1979, GB 1797-1986, GB 1799-1986, GB 1797-2001. raw silk

1 Scope

China's national product standard for raw silk - the reeled filament as it leaves the filature, before any throwing, degumming or dyeing. It specifies the requirements for the skeins and packages, the grading, the inspection rules, and the packaging and identification of raw silk, and it applies to non-dupion raw silk of nominal size 69 denier and finer. Raw silk is the only textile fibre sold as a continuous filament straight from the animal, and it is graded rather than simply passed or failed. Grade is what the price is set on, and the grading system exists because the defects of raw silk are unlike those of any staple yarn. Size deviation and size maximum deviation measure how constant the filament thickness is along its length, which decides whether a woven fabric shows bars and streaks - the defect a silk weaver fears most, since it appears only after weaving. Evenness variation, cleanness and neatness are graded by comparison against standard photographs under prescribed lighting, and they measure the frequency of the slubs, loops, nibs and long knots that come from the reeling operation. Tenacity and elongation, cohesion, and winding performance decide whether the silk survives throwing and weaving without breaking. Together with the moisture regain and the boil-off loss, which determine how much of the invoiced weight is silk at all, these are what the grade is built from. The standard fixes the levels for each grade, the requirements on the skein and package - the physical form in which silk is traded and in which it can be damaged - and the inspection rules that decide a lot. Test methods are in GB/T 1798. Issued on 6 August 2008 and in force since 1 June 2009, it replaces GB 1797-2001.

This standard specifies the installation and twisted silk cartridges requirements, inspection rules, packaging and identification. This standard applies to nominal fineness of 69den not soak silk and below.

2 Normative references

The following documents contain provisions which, through reference in this standard and become the standard terms. For dated references, subsequent Amendments (not including errata content) or revisions do not apply to this standard, however, encourage the parties to the agreement are based on research Whether the latest versions of these documents. For undated reference documents, the latest versions apply to this standard.

GB/T 1798-2008 Test methods for raw silk

3 Silk labeling specifications

Silk specification of "fineness floor/ceiling fineness" label, which is the nominal center fineness fineness. Example.

a) 20/22den. Represents a nominal fineness of silk is 21den, fineness of silk specification limit for 20den, fineness limit of 22den.

b) 40/44den. Represents a nominal fineness of silk is 42den, fineness of silk specification limit for 40den, fineness limit of 44den.

4 Requirements

4.1 Quality of raw silk, raw silk according to the subject of comprehensive performance quality specifications and appearance quality, divided into 6A, 5A, 4A, 3A, 2A, A and Class-drugs.

4.2 silk quality technical indicators specified in Table 1. Table 1 raw silk quality specifications prescribed The main test items on behalf of the fineness level 6A 5A 4A 3A 2A A Fineness deviation / den 12den (13.3dtex) And below 0.80 0.90 1.00 1.15 1.30 1.50 13den ~ 15den (14.4dtex ~ 16.7dtex) 0.90 1.00 1.10 1.25 1.45 1.70 16den ~ 18den (17.8dtex ~ 20.0dtex) 0.95 1.10 1.20 1.40 1.65 1.95 19den ~ 22den (21.1dtex ~ 24.4dtex) 1.05 1.20 1.35 1.60 1.85 2.15 23den ~ 25den (25.6dtex ~ 27.8dtex) 1.15 1.30 1.45 1.70 2.00 2.35 26den ~ 29den (28.9dtex ~ 32.2dtex) 1.25 1.40 1.55 1.85 2.15 2.50 30den ~ 33den (33.3dtex ~ 36.7dtex) 1.35 1.50 1.65 1.95 2.30 2.70