Standard No.:	GB/T 2910.25-2017
English Name:	Textiles―Quantitative chemical analysis―Part 25:Mixtures of polyester and certain other fibres（method using trichloroacetic acid and chloroform）
Chinese Name:	纺织品 定量化学分析 第25部分：聚酯纤维与某些其他纤维的混合物（三氯乙酸/三氯甲烷法）
Chinese Classification:	W04    Basic standards and general methods
Professional Classification:	GB    National Standard
ICS Classification:	59.080.01 59.080.01     Textiles in general 59.080.01
Source Content Issued by:	AQSIQ; SAC
Issued on:	2017-12-29
Implemented on:	2018-7-1
Status:	valid
Target Language:	English
File Format:	PDF
Word Count:	3500 words
Translation Price(USD):	100.0
Delivery:	via email in 1 business day

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative. GB/T 2910 consists of the following parts under the general title Textiles - Quantitative chemical analysis: ——Part 1: General principles of testing; ——Part 2: Ternary fibre mixture; ——Part 3: Mixtures of acetate and certain other fibres (method using acetone); ——Part 4: Mixtures of certain protein and certain other fibers (method using hypochlorite); ——Part 5: Mixtures of viscose, cupro or modal and cotton fibres (method using sodium zincate); ——Part 6: Mixtures of viscose or certain types of cupro or modal or lyocell and cotton fibres (method using formic acid and zinc chloride); ——Part 7: Mixtures of polyamide and certain other fibres (method using formic acid); ——Part 8: Mixtures of acetate and triacetate fibres (method using acetone); ——Part 9: Mixtures of acetate and triacetate fibres (method using benzyl alcohol); ——Part 10: Mixtures of triacetate or polylactide and certain other fibres (method using dichloromethane); ——Part 11: Mixtures of cellulose and polyester fibres (method using sulfuric acid); ——Part 12: Mixtures of acrylic, certain modacrylic, certain chlorofibres, certain elastanes and certain other fibres (method using dimethylformamide); ——Part 13: Mixtures of certain chlorofibers and certain other fibers (method using carbon disulfide/acetone); ——Part 14: Mixtures of acetate and certain chlorofibers (method using acetic acid); ——Part 15: Mixtures of jute and certain animal fibres (method by determining nitrogen content); ——Part 16: Mixtures of polypropylene and certain other fibres (method using xylene); ——Part 17: Mixtures of chlorofibers (homopolymers of vvinyl chloride) and certain other fibers (method using sulfuric acid); ——Part 18: Mixtures of silk and wool or hair (method using sulfuric acid); ——Part 19: Mixtures of cellulose fibres and asbestos (method by heating); ——Part 20: Mixtures of elastane and some other fibers (method of using dimethylacetamide); ——Part 21: Mixtures of chlorofibers, certain modacrylics, certain elastanes, acetates, triacetates and certain other fibers (method using cyclohexanone); ——Part 22: Mixtures of viscose or certain types of cupro or modal or lyocell and flax of ramie fibres (method using formic acid and zinc chloride); ——Part 23: Mixtures of polyethylene and polypropylene (method using cyclohexanone); ——Part 24: Mixtures of polyester and some other fibres (method using phenol and tetrachloroethane); ——Part 25: Mixtures of polyester and certain other fibres (method using trichloroacetic acid and chloroform); ——Part 26: Mixtures of melamine and cotton or aramide fibers (method using hot formic acid); ——Part 101: Mixtures of soybean protein composite fibre and certain other fibers. This is Part 25 of GB/T 2910. This part is developed in accordance with the rules given in GB/T 1.1-2009. This part has been redrafted and modified by adoption of ISO 1833-25:2013 Textiles - Quantitative chemical analysis - Part 25: Mixtures of polyester and certain other fibres (method using trichloroacetic acid and chloroform). The main technical differences with respect to ISO 1833-25:2013 are as follows: ——the adjustments on technical differences are made for the normative references of this part to adapt to the technical conditions in China, which are mainly reflected in Clause 2 "Normative references”, with the following specific contents:  ISO 1833-1 is replaced by GB/T 2910.1, which is identical to the international standard. ——In the scope, the types of applicable fibres are defined to express more clearly. ——the values of d for some fibres are added in the calculation and expression of results, which correspond to the fibre types listed in the applicable scope. ——precision is added to indicate the confidence limit of test results of this method. The following editorial changes have been made in this part: ——the international standards in "Bibliography” are replaced by corresponding Chinese standards. This part was proposed by the China National Textile and Apparel Council. This standard is under the jurisdiction of National Technical Committee on Textiles of Standardization Administration of China (SAC/TC 209). Textiles - Quantitative chemical analysis - Part 25: Mixtures of polyester and certain other fibres (method using trichloroacetic acid and chloroform) Warning: It has been assumed in the drafting of this part that the execution of its provisions is entrusted to appropriately qualified and experienced people. This part does not address all of the safety problems. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any national regulatory conditions. 1 Scope This part of GB/T 2910 specifies a method using trichloroacetic acid and chloroform to determine the percentage of polyester fibres after removal of non-fibrous matter, in binary mixtures of polyester fibres with other fibres such as cellulose fibre (cotton, flax, ramie, viscose fibre, modal fibre, lyocell fibre, copper ammonia fibre), animal hair fibre (wool, cashmere, etc.) and synthetic fibre (polyacrylonitrile fibre, aromatic polyamide fibre). This part is applicable to the mixture of polyester fibre and some other fibres. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 2910.1 Textiles - Quantitative chemical analysis - Part 1: General principles of testing (GB/T 2910.1-2009, ISO 1833-1:2006, IDT) 3 Principle The polyester fibre is dissolved out from a known dry mass of the mixture, with a reagent composed of trichloroacetic acid and chloroform. The residue is collected, washed, dried and weighed; its mass, corrected if necessary, is expressed as a percentage of the dry mass of the mixture. The percentage of polyester is found by difference. 4 Reagents Use the reagents described in GB/T 2910.1, together with those specified in 4.1, 4.2 and 4.3. 4.1 Solution of crystallized trichloroacetic acid/chloroform reagent, prepared at a mass ratio 1:1. Safety precautions: the harmful effects of this reagent shall be borne in mind, and full precautions shall be taken during use. 4.2 Solution of 15g trichloroacetic acid filled up to 100g with chloroform. 4.3 Chloroform. 5 Apparatus Use the apparatus described in GB/T 2910.1, together with that described in 5.1. 5.1 Conical flask, of minimum capacity of 200mL, glass stoppered. 6 Test procedure Follow the general procedure described in GB/T 2910.1, and then proceed as follows. 6.1 Place the specimen in the conical flask. 6.2 Add 50mL trichloroacetic acid/chloroform reagent (4.1) per gram of specimen. 6.3 Stopper the conical flask and shake it vigorously. 6.4 Allow the flask and contents to remain for 15min, shaking it during this time at intervals. 6.5 Decant the liquid through the filter crucible with suction. 6.6 Pour 100mL trichloroacetic acid/chloroform reagent (4.1) into the conical flask, decant the liquid through the filter crucible, and then transfer any residual fibres to the crucible by washing out the conical flask with the trichloroacetic acid/chloroform solution (4.2) followed by chloroform (4.3). 6.7 Drain the crucible with suction after the washing liquor has drained under gravity for each time. 6.8 Finally, dry the crucible and residue, cool and weigh them. 6.9 Check the residue under a microscope to see if the treatment completely eliminated the soluble fibre. 7 Calculation and expression of results Calculation and expression of results shall comply with GB/T 2910.1. The value of d is 1.02 for cotton, 1.01 for flax, and 1.00 for other fibres.

Foreword i 1 Scope 2 Normative references 3 Principle 4 Reagents 5 Apparatus 6 Test procedure 7 Calculation and expression of results 8 Precision Bibliography