How to reduce the color difference between large and small samples when dyeing acrylic yarn is a very complicated problem, causing There are many reasons for the color difference between large and small samples. We can only briefly analyze the reasons for the color difference between large and small samples under normal circumstances as follows:
① Be sure to be strict and precise when making color samples
Prototype making is the key to directly affecting the large-scale production in the workshop, and it must be fully understood importance to avoid differences between large samples and small samples. When making small samples, you should pay attention to the following issues: a: The water used for making small samples should be consistent with the water used for production of large samples to avoid water quality problems that will affect the color difference between large samples and small samples. b. The dyes and auxiliaries used for making small samples must be of the same batch number, same strength, and same brand. The concentration of dye absorbed by the sample should be appropriately selected using a straw. Try not to use a large straw to absorb a small volume of dye solution. The dyes and auxiliaries used in the sample must be current and ready for use. c. The acrylic yarn sample used in the small sample, including the pre-treatment method, must be consistent with the large sample. When color matching, you must choose a K value that is the same or similar to the K value of the dye, that is, the compatibility values of the dyes must be basically the same. At the same time, you must also choose a retarder that has the same K value as the dye or a difference of no more than 1, so as to ensure that each dye in the dye solution The proportional relationship between them is conducive to the stability and reproducibility of dyeing quality and color light. d. The pH value of the dye bath and the heating process for proofing should be the same as or close to those of mass production. e. Color matching should be strictly accurate.
② Error in weighing dye additives for large samples
When weighing dyes for small samples, an analytical balance or electronic balance should be used, and the use of weight scales should be avoided to minimize errors. When weighing dyes for large sample production, weight scales should be used as much as possible, and balances and bench scales should be checked frequently.
③ Strictly control the pH value of the dye bath
The pH value is generally controlled more carefully in small sample production. Due to the cross-use of water quality and direct steam or indirect steam during large sample production, the boiler steam often brings alkalinity and makes the dye bath pH higher. When dyeing acrylic fiber, the dye bath The pH value should be kept within the range of 4.5 to 5, otherwise the color will change and color differences will occur. If the pH value is higher, the dye uptake rate and reproducibility of the dye will be affected, and the color difference between large and small samples should be greater.Strengthen the measurement of pH value in the dye bath or use buffers, or install an online pH value monitor.
④ Control the dye bath ratio
When making small samples, the bath ratio is generally larger (1:30), while the dyeing bath ratio for large samples is smaller (about 1:10). In order to avoid different bath ratios for large and small samples, the bath ratio is dependent on certain cationic dyes. It is more sensitive to sex, so it must be emphasized that the sample making should be done in the package dyeing sample machine.
⑤ Strictly implement process operations
Practice has proved that different process operations are also one of the reasons for the color difference between large and small samples. Process operations including dye dissolution, acetic acid dosage, adding methods of dyes and additives, heating procedures, boiling dyeing time, etc. should be strictly operated according to process requirements and cannot be changed arbitrarily. The sampling personnel should be familiar with the process operation. After the color light of the small sample is determined, the sampling personnel should go into the workshop to conduct pioneer tests to ensure the consistency between the production of small samples and large samples.
Extended reading: https://www. alltextile.cn/product/product-36-562.html
Extended reading: https://www.tpu-ptfe.com/post/7718.html
Extended reading:https://www.alltextile.cn/product/product-22-781.html
Extended reading: https://www.china-fire-retardant.com/post/9406.html
Extended reading:https://www.china-fire-retardant.com/post/9378.html
Further reading: https://www.brandfabric.net/full-dull-nylon-taslon-oxford-breathable-fabric/
