How to whiten chemical fiber, and which fluorescent whitening agent is effective?

Chemical fiber is a kind of fiber with textile properties, which is made from natural polymer compounds or synthetic polymer compounds as raw materials, through the processes of preparation of spinning dope, spinning and subsequent treatment. Chemical fiber is widely used in the manufacture of clothing fabrics, filter cloth, conveyor belts, hoses, ropes, fishing nets, electrical insulation wires, medical stitches, tire cord cloth and parachutes, etc. Generally, polymer compounds can be made into solution or melt, extruded from the fine hole of spinneret, and then solidified to form fibers. The product can be continuous filament, chopped short fiber or unbroken tow, etc.

Short fiber, also known as polyester short fiber, is the fiber obtained by cutting the tow spun from polyester. Trade name of chemical fiber: China temporarily stipulates that all synthetic short fibers should be named "nylon" (for example, Dacron, polyamide fiber), all cellulose short fibers should be named "fiber" (for example, viscose fiber and cuprammonia fiber), and filament fibers should be added with the word "silk" at the end, or the words "nylon" and "fiber" should be changed to "silk". Among chemical fiber staple fibers, polyester is what we hear more about. Today, taking polyester as an example, let's talk about what special fluorescent whitening agent for chemical fiber polyester should be used.

Polyester itself has a certain whiteness, but in order to meet the requirements of specific whiteness and shade, it needs to be whitened with fluorescent whitening agent. Because of its structure and characteristics, it is difficult to whiten polyester fiber, so hydrophilic fluorescent whitening agent can't be used for whitening. Generally, non-aqueous dispersed fluorescent whitening agent is used to make a stable dispersion, and then the fluorescent whitening agent is diffused into the fiber by special methods such as hot-melt dyeing, high-temperature and high-pressure dyeing or carrier dyeing (by thermal movement diffusion and sublimation into the fiber) and evenly distributed in it for whitening. Sometimes when batch process is used, it is often carried out in the same bath as bleaching. For the whitening of polyester puree, the powder product of dispersed fluorescent whitening agent can be directly used.

Therefore, the fluorescent whitening agent used for polyester should have good thermal stability and high sublimation fastness resistance, light fastness and chlorine bleaching fastness. According to the types of fluorescent whitening agents, there are azole, coumarin, stilbene, naphthalimide, triazinyl pyrene and so on.

The varieties of special fluorescent whitening agents for polyester fiber are: C.I. fluorescent whitening agents 135.179, 185, 199 and their isomers, 229, 236, 367, 368, 393, etc. Among them, C.I. fluorescent whitening agent 199 and its derivatives, 236, 378, 393 and 368, and C.I. fluorescent whitening agent 199 and its derivatives for polyester staple fibers can be used for whitening.

Seeing so many chemical code names, you are dazzled. In order to enable customers to find the fluorescent whitening agents they need more quickly in our company official website, we subdivide the fluorescent whitening agents according to their uses, such as plastic fluorescent whitening agents, washing fluorescent whitening agents, and chemical fiber fluorescent whitening agents mentioned today, etc.