Standard for inspection rules for cotton and chemical fiber pure and blended natural colored yarns

This standard specifies the acceptance, inspection items, inspection methods, and retest requirements for cotton and chemical fiber pure and blended natural color yarns.

This standard is applicable to the quality acceptance and re inspection of cotton and chemical fiber pure and blended natural color yarns by both parties or entrusted inspection institutions.

2 Acceptance

2.1 The production factory shall issue product instructions based on the product inspection results, and the recipient shall verify the contents of the instructions and packaging marks according to the standards and protocols of the product for acceptance.

2.2 If the recipient is unable to conduct acceptance inspection due to conditions, they should receive the goods according to the manufacturer"s product manual.

3 Inspection items

The inspection items for yarn include the provisions of the standard technical requirements of each product and the inspection of the net weight of the package. Users can inspect yarn defects and the appearance of yarn formation during use.

4 Inspection methods

4.1 Inspection of technical requirements and indicators in product standards

4.1.1 Sampling shall be based on the principle of uniform and equal quantity, with random sampling. One sample, three packages of packages and twisted yarn, shall be taken. When the batch size is 2 tons or less, sampling shall be carried out according to the product standard. When the batch size is more than 2 tons, sampling shall be doubled once for calculation.

4.1.2 Technical requirements: The inspection methods for various indicators shall be in accordance with the test method standards in the product standard.

4.1.3 For yarns that have undergone thermal setting, if the setting temperature is 40 ℃ or above, the single yarn breaking strength shall be reduced by 5% according to the specified indicators for acceptance.

4.1.4 In the net weight inspection of package yarn, if the moisture regain is inconsistent with the electric oven and package moisture tester, the moisture regain measured by the electric oven shall prevail.

During the acceptance of various types of yarn production batches, the coefficient of variation of 100 meter weight should be increased by 0.4 according to the values specified in the corresponding standards.

4.1.6 The weight deviation range of singeing yarn should be increased by 0.4 evaluation products according to the corresponding standard values. If it is not accepted according to the production batch, the coefficient of variation of 100 meter weight should be increased by 0.4 evaluation products.

4.1.7 The weight deviation range of singeing yarn shall be increased by 0.5 according to the values specified in the corresponding standards for evaluation products.

4.2 The weight of the net weight of the package shall be based on the declared moisture regain. When the actual moisture regain exceeds or is less than the declared moisture regain, the actual weight shall be taken as 2 packages (boxes) if the inspection quantity is less than 2 tons, and 5% of the total package (box) if the inspection quantity is 2 tons or more, but not more than 15 packages (boxes). The allowable deviation for the net weight of each batch of bobbin yarn packaging is within -0.2%, and the allowable deviation for the net weight of twisted yarn packaging (after removing the influence of Tex series differences on weight) is -0.5%. If the allowable deviation is exceeded, all differences should be compensated.

4.3 If any defects affecting the processing and finished product quality are found before and during the use of the yarn, and after research by the manufacturer, it is confirmed that they are caused by the manufacturer, then the hank yarn can be adjusted or compensated at a discounted price by the original manufacturer, starting from the large hank or bobbin yarn.

4.4 Inspection of yarn defects.

The spinning factory shall be responsible for yarn defects, such as significant degradation of rear products due to yarn fatigue.

When special quality issues (such as mixed fibers, yellow and white yarn, etc.) that cannot be detected on yarn or grey fabric cause a large amount of grade reduction in printed and dyed products, after joint analysis, it is determined that the spinning factory should be responsible for the losses caused by the grade reduction of printed and dyed products, or both parties should negotiate and handle them.

5 Re-inspection

If there are any objections during the handover and acceptance of yarn, both parties can jointly conduct a re inspection or entrust a professional inspection agency to conduct arbitration inspection. Both the re inspection and arbitration inspection shall be based on one time.

5.2 The products required for re inspection should be products of the same delivery batch, variety, and grade, and are limited to steamed products that have not been processed or used within one year of leaving the factory.

When requiring re inspection, all the required re inspection quantity should be retained. However, in order to not affect the production of the processing enterprise, 20% of the required re inspection quantity should be retained for quality indicators. The number of twisted yarns should not be less than 3 whole packages (medium or large packages), and the number of bobbin yarns should not be less than 6 boxes (packages). However, when it is required to retest the net weight of the finished product, all required retest quantities should be retained.

5.4 After receiving the notice of request for re inspection, the production factory should immediately go to handle it, and the time should not exceed two weeks. Otherwise, the production factory should bear the opinions raised by the other party.

All expenses incurred during the re inspection shall be borne by the responsible party.

5.6 If the quality of the product is affected or changed due to poor transportation or storage by the receiving party, no request for re inspection or compensation shall be made.

Appendix A

Provisional Regulations on Yarn Acceptance (Supplementary)

A1 yarn defects should be inspected and graded before the yarn leaves the factory. However, due to the immaturity of yarn defect inspection methods, the current approach is to inspect yarn defects from later products.

The inspection and handling methods for yarn defects in A2 natural color fabrics are as follows:

A2.1 Temporarily inspect the four important yarn defects of coarse warp, coarse weft, slub yarn, and uneven evenness on natural colored fabrics.

A2.2 The appearance defects of the natural color shall be inspected according to GB/T406 "Cotton Natural Color Cloth". Any defects in coarse warp, coarse weft, slub yarn, and uneven evenness that are degraded at one point shall be considered as yarn defect degraded fabric. Record and count after fabric inspection and before fabric repair.

A2.3 When the total number of pieces of coarse warp, coarse weft, slub yarn, and unevenness of a single use degraded fabric accounts for more than 2% of the total monthly inspection quantity of the same variety, the yarn production factory shall bear the loss of the price difference of the defective degraded fabric.

A2.4 Weaving factories should carefully record and count yarn defects and degraded fabrics. For daily minor yarn defects, the spinning factory should be notified on schedule. For sudden yarn defects, the spinning factory should be notified in a timely manner and the degraded fabric should be retained for joint analysis.

Yarn A2.5 has been downgraded to second class, and the spinning factory is no longer responsible for the degradation caused by yarn defects.

The inspection and handling methods for defects in A3 knitted yarn are as follows:

The yarn defects of A3.1 knitting yarn include large magazines, large knots, slub yarn, fine sand, coarse sand, large knots, and flying attachment.

A3.2 The inspection of yarn defects for knitting is conducted on the fabric surface of knitted grey fabric, and the number of yarn defects on a certain weight of fabric surface is counted. The inspection quantity and processing method shall be determined through consultation between the spinning and knitting factories.

Additional statement:

This standard is under the jurisdiction of Shanghai Textile Standards Research Institute.

This standard is drafted by Shanghai Textile Bureau, Beijing Textile Industry Corporation, and Hebei Textile Industry Corporation.

From the date of implementation of this standard, the original national standard GB 405-78 "Acceptance Rules for Natural Color Cotton Yarns" shall be invalidated.