Textile salespeople must understand these printing and dyeing knowledge!

With the development of society, the improvement of production and living standards, and the upgrading of products of textile fabric manufacturers, if you want to be a qualified textile person, of course you must have the idea of ​​​​advancing with the times. You only know a single gray fabric quality indicator or Technology, it is inevitable that we often encounter some problems in the process of work.

For example, problems that often occur in dyeing often require you to judge whether it is a problem with the dyeing factory or with the gray fabric. At this time, you need to know some knowledge about printing and dyeing, which I will introduce today. Let’s look at common problems in textile dyeing.

1. Reasons for dyeing defects

1. Reasons for gray fabrics:

Many potential defects in dyed fabrics are caused by poor quality of gray fabrics. Such as weaving defects and yarn cracks. Due to the mixing of different batches of yarn, weaving defects such as warp willows, warp strips, weft bars and weft streaks are formed on the fabric. For the above problems, the salesperson should know and understand before sales. Understand that the best solution is to bleach and make bleached cloth.

2. Reasons for pre-treatment:

Good pre-treatment of fabrics is the basis for processing high-quality products. Poor pre-treatment will cause many dyeing defects. ①The appearance of the fabric surface is uneven due to poor singeing. The fluffy black flowers and color spots caused by the flame gap of the singeing machine, especially light-colored ones, are caused by the molten balls produced by the synthetic fibers during singeing. When the singeing machine is improper or contaminated, it will produce spots of charcoal or tar-like substances. If the singeing flame is too strong or excessive, it will cause a rough and hard feel. ② Uneven desizing can cause dye stains or pulp spots. Condensation water droplets dripping from rusty pins or fabrics that come into contact with rusty surfaces in the cloth boiler can cause rust spots. The cause of deep dye spots and oil stains is that the gray cloth is not fully simmered, resulting in uneven whiteness and uneven mercerization. From the pre-treatment to the next dyeing process, the fabric should be cold, with a pH value close to neutral, and no residual alkali. This can prevent problems such as head-to-tail color difference, dark or light color, color fixation, and uneven coloring.

2. Common defects in long lathe dyeing

1. Wrinkles are caused by uneven tension on the fabric on the padding car or serious pressure passing through the padding point. Wrinkles will occur if the guide roller is bent or deformed, the guide roller or drying cylinder bearings are worn, dirt accumulates on the guide roller or drying cylinder, the drying cylinder is not arranged in a line, the drying cylinder temperature is inappropriate, etc.

2. The main reasons for the color difference between the left and right sides and the edges are uneven pressure at the rolling points, residual alkali agents, surfactants and silicon salts in the fabric, different degrees of roller damage, and the selection of rollers. Reasons such as inappropriateness.

3. Dyeing spots are caused by poor preparation of powder dye, insufficient filtration, improper preparation temperature, improper storage or stirring of slurry dye, and improper composition of the dye bath.

4. Water stains, the main reason is that the temperature of the interlayer at the top of the steamer is too low, and the entrance of the steamerThere is condensed water and the guide roller in the steamer does not rotate.

5. Poor washing resistance, abrasion resistance and light fastness. The reason is the deposition of unfixed dye on the fabric.

6. Light stains are caused by excessive accumulation of dirt and lint on the guide roller.

7. Color change. The reason is that the structure of the dye chromophore often changes due to changes in certain external conditions, resulting in certain changes in the color light. Common conditions include temperature, humidity, light and light source.

8. Color difference between large and small samples. The reason is that there are differences in the dyeing process of large and small samples, such as the use of dyeing materials, padding time, fixation time and temperature, etc., the difference in weighing accuracy of different equipment used, the difference in pre-treatment semi-finished products, and the water content. Select etc. This will cause differences between large and small samples, so small samples must be replicated before finalizing the large-scale production process.