GB/T 37630-2019 English PDF (GBT37630-2019)

This Standard specifies the method for determining the fiber content in the mixture of acetate or triacetate and certain other fibers after removing the non-fibrous materials by the hydrochloric acid method. This Standard is applicable to the binary mixture of acetate fiber with wool, cashmere, other animal fibers, silk, cotton, ramie, linen, viscose fiber, modal fiber, lyocell fiber, polyacrylonitrile fiber, polyester fiber, spandex and polylactic-acid fiber; as well as the binary mixture of triacetate fiber with polyacrylonitrile fiber, polyester fiber, and polylactic-acid fiber.

GB/T 37630-2019
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 59.080.01
W 04
Textiles – Quantitative Chemical Analysis – Mixtures
of Acetate or Triacetate with Certain Other Fibers
(Method Using Hydrochloric Acid)
ISSUED ON: JUNE 04, 2019
IMPLEMENTED ON: JANUARY 01, 2020
Issued by: State Administration for Market Regulation;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative References ... 4
3 Principle ... 4
4 Reagents ... 5
5 Equipment ... 5
6 Test Procedures ... 5
7 Calculation and Expression of Results ... 6
8 Precision ... 6
9 Test Report ... 7
Textiles – Quantitative Chemical Analysis – Mixtures
of Acetate or Triacetate with Certain Other Fibers
(Method Using Hydrochloric Acid)
1 Scope
This Standard specifies the method for determining the fiber content in the mixture of acetate or triacetate and certain other fibers after removing the non-fibrous materials by the hydrochloric acid method.
This Standard is applicable to the binary mixture of acetate fiber with wool, cashmere, other animal fibers, silk, cotton, ramie, linen, viscose fiber, modal fiber, lyocell fiber, polyacrylonitrile fiber, polyester fiber, spandex and polylactic-acid fiber; as well as the binary mixture of triacetate fiber with polyacrylonitrile fiber, polyester fiber, and polylactic-acid fiber.
Other similar fibers can refer to this Standard.
2 Normative References
The following documents are essential to the application of this document. For the dated documents, only the versions with the dates indicated are applicable to this document; for the undated documents, only the latest version (including all the amendments) are applicable to this document.
GB/T 2910.1 Textiles - Quantitative Chemical Analysis - Part 1: General Principles of Testing
3 Principle
Use hydrochloric acid to dissolve and remove the acetate or triacetate fibers from the mixture with known dry mass; collect the residue; clean, dry and weigh; calculate the percentage of the corrected mass accounting for the dry mass of the mixture. Then calculate the mass percentage of acetate or triacetate fibers from the difference. neutralize for twice; then use clean water to wash. Firstly, conduct the gravity drainage, then conduct the pumping drainage for each washing; finally, dry, cool-off, weigh the crucible and the residue.
6.2 Mixture of triacetate fibers with certain other fibers
Pipette hydrochloric acid solution (4.1); its consumption shall be calculated by adding 100mL of solution (4.1) per gram of specimen. Then add it into the conical flask; pre- heat to (60±2) °C; then place the specimen into the conical flask; cover the stopper; shake the conical flask to make it fully wet; then oscillate on the (60±2) °C constant temperature water bath oscillator (5.2) for 70min. Use the glass sand core with known mass to filter; wash the remaining fibers with a small amount of hydrochloric acid solution (4.1) at the same temperature for 3 times. Then use clean water to wash for 4~5 times; then use of dilute ammonia solution (4.2) to neutralize for twice. Firstly, conduct the gravity drainage, then conduct the pumping drainage for each washing; finally, dry, cool-off, weigh the crucible and the residue.
NOTE: In case some dark samples are not completely dissolved, the reagent can be replaced once during the dissolving process; and appropriately extend the dissolution time. 7 Calculation and Expression of Results
The calculation and expression of results shall be as specified in GB/T 2910.1. The value-d for mixture of acetate fiber and other fibers, cotton, ramie, viscose fiber, lyocell fiber, modal fiber, cashmere is 1.01; the Value-d for linen is 1.04; the Value-d for silk, spandex is 1.02; and the Value-d for other fibers is 1.00.
The Value-d for mixture of triacetate fiber and other fibers, polyacrylonitrile fiber, polyester fiber, polylactic-acid fiber is 1.00.
If the error of the measures results of two specimens is greater than 1%, take the third specimen; the measured results shall be expressed by the average of the three measured results.
8 Precision
For the homogeneous textile material mixture, the confidence limit for this Standard test results does not exceed ±2% at a 95% confidence level.