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- Three minutes to understand the pretreatment, dyeing and finishing process!
- Three minutes to understand the pretreatment, dyeing and finishing process!I. Preparation of original cloth
The preparation of the original cloth includes the inspection of the original cloth, the turning cloth (batch, sub-box, printing) and the sewing head. The purpose of original cloth inspection is to check the quality of grey cloth and find problems that can be solved in time. The content of inspection includes two items: physical index and appearance defect. The purpose of singeing is to burn down the fluff on the fabric surface, to make the fabric smooth and beautiful, and to prevent uneven dyeing and printing defects due to the existence of fluff in dyeing and printing. In order to weave smoothly in Desizing textile mills, warp sizing is often used to improve strength and wear resistance. Sizing on grey cloth affects the water absorption of fabric, the quality of dyeing and finishing products, and increases the consumption of dyeing and chemical drugs. Therefore, sizing should be removed before scouring. This process is called desizing.
Two, dyeing
Dyeing is a relatively complex process, and the dyeing process of different quality cloth is different, such as cotton, polyester cotton, nylon, polyester, chemical fiber products, blended products and so on. Some use pad dyeing and jig dyeing, some must use high temperature and high pressure dyeing, some only dye once, and some need to be colored many times. Although dyeing can be done through a rolling mill, it is also the most difficult process, because besides the known color control, there are many unknown things in it, such as the stability of dyes at different temperatures, the control of steam, the control of rolling pressure and so on, which are very delicate activities.
The dyeing cart is divided into two parts: front car dyeing and rear car fixing. The dyeing methods vary according to the variety of dyes selected. Dyes are generally active, disperse, sulfurized and coated. They have their own advantages and disadvantages. Generally, they depend on the required color and can not be replaced each other.
III. Post-collation
Finishing is a textile technology engineering that gives clothing fabric wearability and beautiful appearance. The following are the common types of textile finishing at present: the main equipments are: singeing machine, desizing machine, mercerizing machine, liquid ammonia machine, setting machine, pre-shrinking machine, calender, washing machine, grinding machine, wool grabber, coating machine, etc.
Dyeing fastness is the most important index of dyed cloth. The ability of printing and dyeing textiles to withstand external effects and maintain their original color is also called color fastness. After dyeing and printing, textiles sometimes go through other processes, such as shrinkage of wool fabrics, thermal setting of synthetic fabrics, etc. In the course of wearing, they should be exposed to atmosphere, sweat stains, washed, rubbed and ironed. All these can make the dyed textiles fade and discolor to varying degrees.
The main processes affecting the dyeing fastness of dyed textiles are shrinkage, carbonization, chlorine bleaching and sublimation. The dyeing fastness of dyes or pigments on textiles is related to their chemical structure, concentration and state on fibers and the properties of fibers. The test methods of dyeing fastness are formulated by simulating various wearing or technological conditions.