Comparison And Discussion On New And Old Standards Of Combed Polyester Cotton Blended Dyed Fabric

GB/T 5326-2009 "combed polyester cotton blended dyed fabric" standard (hereinafter referred to as the new standard) was released in April 21, 2009, and was formally implemented on December 2009, replacing the standard of GB/T 5326-1997 combing polyester cotton blended dyed fabric for 13 years (hereinafter referred to as the old standard) for 13 years.

The new standard expands the scope of application, increases the quality assessment index, and the appearance quality refers to the four mark system of the US standard, which makes the whole standard more international, scientific and reasonable.

The differences between the contents of the new and old standards are compared and discussed from the following 6 aspects.

The old standard is applicable to the quality of all kinds of bleached, dyed and printed cotton blended fabrics with 50% or more combed polyester staple fiber.

The new standard extends to the quality of all kinds of bleached, dyed and printed cotton blended fabrics, including 50% or more combed polyester staple fibers.

The increase of home textiles has solved the phenomenon that the combed polyester cotton blended fabric has no standard to comply with.

In the new standard and normative reference document, GB18401 - 2003 national textile product basic safety technical specification is adopted as the reference standard.

(1) tearing strength is implemented as an internal control index item in the old standard, but in practice, enterprises generally do not make an assessment, and the new standard clearly stipulates that tear strength is used as an assessment index.

There are two kinds of assessment indexes: yarn fabric and thread fabric.

(2) the size change rate of washing is divided into two categories: the old standard yarn and the thread fabric according to the blending ratio. The new standard is divided into two categories: yarn fabric and thread fabric, and the adaptability of the assessment index is adjusted.

(3) increased fiber content deviation assessment.

In the old standard, there is no index for blending ratio of blended products, and the new standard stipulates that the fiber content of superior products, first grade and two grade products should be checked, and the content deviations are the same.

This is conducive to the strict control of product quality and the interests of consumers.

(4) in the color fastness assessment of the old standard, the color fastness to perspiration and the color fastness to heat were evaluated individually, and the assessment indexes were different.

The assessment of scrubbing fastness was deleted. This is because the washing method has changed with the improvement of people's living standard, which makes the assessment index more humanized.

The grading of old standards is superior, first class, two grade, three and so on. In the new standard, only superior products, first grade and two products are divided into three grades, so that enterprises and testing institutions can be more operable.

(1) considering the current situation of our country and the need to integrate with the international market and the color fastness in the old standard and the GB/T 5325 to 2009 combing polyester cotton blended fabric, the new standard is changed from a localized defect system to a four point system according to the US standard, allowing the score to be changed from sub meter to sub square meter, with the exception of blemish, the rest takes 0 starting points.

(2) the allowable degree of appearance dispersion defects has been modified.

In the old standard, the width deviation is divided into four specifications. The new standard combines four kinds into two kinds, and the index data are adjusted accordingly.

(3) color difference level.

The requirement of positive and negative chromatic aberration in the old standard has been abolished, and the color difference level has been improved correspondingly in the original left, right and right.

The appendix of the old standard includes three categories: A, B and C.

Appendix A is the calculation of the processing coefficient and width, density and breaking strength of combed polyester cotton blended dyed fabric. Appendix B is the revision of the temperature and moisture regain for measuring the breaking strength at room temperature. Appendix C is the internal control item of combed polyester cotton blended dyeing and printing.

The breaking strength has specific assessment indexes in the old and new standards. Therefore, appendix A and appendix B of the old standard have been cancelled. Because the tear strength index has increased from the original internal control index to the assessment index, the crease recovery angle index is not required, so the appendix C of the old standard has also been removed.

The new standard only takes the index of width and density as the appendix A.

By analyzing and comparing the contents of the two standards, the following problems need to be further improved: the new standard mentioned in the preface the assessment of adding safety technology requirements, but the author found that there were no safety technical requirements in the assessment of new standard indicators.

The new standard fiber content deviation assessment index is 3%, expressed as net dry weight percentage, but the finished products made of such fabrics, such as the standard content of fiber in the shirt standard, are calculated according to the standard moisture regain. The requirement of the textile product content index is based on the FZ/T01053 - 2007 standard test of textile fiber content, and the standard deviation is 5%.

Therefore, it is suggested to further improve the national standards so as to better serve the testing work.