The Cotton Knitted Underwear testing has made major revisions and supplements in the setting of technical requirements and assessment indicators. It refers to the advanced standards of industry products, which not only protects the rights and interests of consumers, but also considers When it comes to the actual situation of the production enterprise, it embodies the principles of advanced technology, reasonable economy, safety, reliability, and coordination, making the standard more complete and reasonable, and more in line with product development trends, which is conducive to the improvement of product quality by the company, and it is also convenient for testing institutions to standardize operations. At the same time, it also reflects the transformation of the standard from a production-directed type to a consumption-directed type.
1 Introduction
Cotton Knitted Underwear testing was formally implemented on June 1, 2015, replacing GB/T 8878-2009 (hereinafter referred to as the old standard). The new standard is a reflection of the improvement of product quality and consumer quality, more clearly standardizes and refines the physical and chemical performance requirements of cotton knitted underwear, and enriches and perfects the basis for determining the quality of finished products. In order to facilitate the quality inspection agencies and enterprise quality management personnel to correctly understand and use the new standards, this article uses a comparative method to illustrate the changes and characteristics of the new standards and the old standards.
2. The main changes in the new standard for cotton knitted underwear testing
The new standard adjusts the format of the requirements and test chapters, deletes the provision that cotton knitted underwear is divided into three categories of single-sided fabrics, double-sided fabrics, and velvet fabrics according to the fabric structure, and modifies and refines the assessment indicators for cotton knitted underwear. details as follows:
1) Cotton Knitted Underwear testing Standard Scope
The new standard clarifies the scope of application of the standard. The new standard is applicable to the identification of the quality of knitted underwear with a cotton fiber content of not less than 50%. In the old standard, the "this standard is applicable to the identification of the quality of cotton knitted underwear. Cotton blended textiles" , Interwoven knitted underwear can refer to the implementation of the provisions. The new standard also clearly stipulates that the new standard does not apply to infant clothing aged 36 months and below.
2) Normative references
The new Cotton Knitted Underwear testing Standard has made appropriate adjustments to the normative reference documents. For all dated reference documents, only the dated version is applicable to the standard. For undated reference documents, the latest version (including all amendments) is applicable to the standard. Compared with the old standard, the cited documents are more standardized.
3) Type
The new standard size is implemented in accordance with GB/T 6411 or GB/T 1335, which is more realistic than the old standard.
4) Internal quality requirements
The new Cotton Knitted Underwear testing Standard deletes the regulation that cotton knitted underwear is divided into three types of products, namely single-sided fabric, double-sided fabric, and fleece fabric according to the fabric structure, and revised the index requirements for bursting strength and washing dimensional change rate. The new standard washing size change rate has made clear regulations on the measuring position, which avoids the operation deviation between different laboratories. The new standard's bursting strength index is obviously stricter than the old standard, and it has higher requirements for the quality of clothing.
The new standard also stipulates that the bursting strength of products and stretch fabrics with slatted, hollowed and burnt-out structures are not assessed for bursting strength, which is more clear than the old standard for hollowing and spandex fabrics that do not assess bursting strength. Breaking through the strong new standards is beneficial to manufacturers in the innovative development of new products, and is in line with the development trend of the industry. The new standard deletes the assessment by fabric classification for the assessment of the washing dimensional change rate, and also clearly stipulates that the elastic fabric does not assess the transverse washing dimensional change rate. The new standard requires pre-conditioning according to the standard atmosphere specified in GB/T 6529 before the washing dimensional change rate test, and testing after the humidity meets the requirements. Deleted the old standard that requires the test of bursting strength and washing dimensional change rate, and the sample should be spread flat on a smooth surface. The laboratory temperature is (20±2) ℃, and the relative humidity is (65±4)%. , Placed 4h and then tested. The new standard also refines the requirements for the measurement location of the washing size change test. The average value of the four lengths of the front and back of the jacket is used as the basis for calculation, and the measurement value of the front body is used as the basis for calculation. The average value is used as the basis for calculation, and the average value of the left and right middle legs is used as the basis for calculation. In the old standard, the instructions for measuring the horizontal measurement of horizontal pants at 8cm from the horizontal crotch measurement line downwards (for children and middle children) are also deleted. The new standard also modified the drying process from "parking for more than 2h" to "resting for more than 4h". The new standard also makes clear provisions for the calculation of the test results in the special case of simultaneous shrinkage and elongation (inverted expansion), and the arithmetic average of two specimens of shrinkage (or elongation) is used as the test result.
5) Regulations on surface defects, etc.
The new Cotton Knitted Underwear testing Standard on surface defects, etc., which is more concise and rigorous than the old standard, and has a better guarantee for the quality of finished products. The new standard also provides a clear definition and explanation for the minor, obvious, and significant defects (minor: not obvious intuitively, but can be seen through careful identification; obvious: does not affect the overall effect, but the existence of the defect can be felt; Significant: Defects that significantly affect the overall effect).
6) Size deviation
The new standard has made large radian modifications to the specification and size deviation, and deleted the classification of adults, middle-aged children, and children in the old standard. The new standard adjusts the specification and size deviation according to the length direction and the width direction, which is more reasonable.
7) Size difference of symmetrical parts
The new standard refines the regulations on the size difference of symmetrical parts. The new standard is more rigorous in assessing the size difference of symmetrical parts, which is more stringent than the old standard, and has a better guarantee for the quality of finished products.
8) Sewing regulations
The new standard is more concise and concise for the textual description of sewing regulations. The requirements of the new standard for sewing are that the shoulders, the crotch forks, and the seam edges should be reinforced. The collar is straight and the thread ends are trimmed. The reinforcement methods required by the old standard have been deleted: four-thread or five-thread overlock stitching, double-needle interlock stitching, back stitching, tacking or adding auxiliary materials. The old standard also deleted the provisions that the seam width of the three-thread overlock sewing machine should not be less than 0.3cm, the four-thread not less than 0.4cm, and the five-thread not less than 0.6cm.
9) Judgment rules
The new standard stipulates that the number of samples shall be randomly sampled according to the variety and color of the batch. In the old standard, the sampled quantity was randomly sampled according to the variety, color, specification and size of the delivery batch. The new standard is more maneuverable in the actual sampling process than the old standard. The new standard also deletes the provisions on the appearance quality of the non-conforming product based on the specification and size. The new standard also revised the re-inspection regulations, and any party can request a re-inspection if it disagrees with the results of the inspection. The results of the re-inspection shall be implemented in accordance with the internal quality and appearance quality regulations in the new standard, and the judgment shall be subject to the results of the re-inspection.
The new Cotton Knitted Underwear testing Standard are more in line with the development trend of cotton knitted underwear products, and have a certain perspective, which can better provide technical basis for product production and trade, and effectively protect the rights and interests of consumers.
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