1. Fluff
From the perspective of flocking, the most commonly used fluff is viscose and nylon fiber. Viscose fiber is made from wood through certain chemical processing, in which the crystal zone of the fiber is 30~40%, and the degree of polymerization is about 250~500. Due to the high crystalline area of viscose fiber, the dye is not easy to penetrate. Generally, it is difficult to get a good blackness when dyeing black, so special dyes and dyeing methods must be used. At the same time, due to its low degree of polymerization, the fiber strength is far less than that of nylon. Generally, dyes suitable for viscose fibers include direct dyes, reactive dyes, vulcanization dyes, etc. NAFTA is also OK, but it is rarely used. Viscose does not soften and melt at high temperature, and begins to change color and decompose at 260~300 ℃.
Nylon fiber is a high molecular material with organic diacid and diamine amino acid or acrylamide as raw materials and connected by amide bond. Nylon fiber has good elasticity, high strength, wear resistance and durability. It is a kind of thermoplastic fiber. Nylon 6 and nylon 66 are commonly used. Nylon fiber has good elasticity and luster, but nylon 66 will turn yellow at 150 ℃, sticky and soften at 230 ℃, and melt at 250 ℃; Nylon 6 softens at 180 ℃ and melts at 215 ℃. Therefore, in the process of wool dyeing, flocking and printing, we must first understand what kind of fiber it is, so that we can correctly select dyes and processes according to their properties, so as not to cause unnecessary losses in the processing process
2. Adhesive
The adhesive used in flocking plays an important role in the post-processing industry of printing and dyeing. Commonly used adhesives are divided into diplomatic adhesives and self crosslinking adhesives. The externally linked adhesive contains carboxyl group (-c00h) or amide group (-c-nh2), amino group (-nh3) and other groups that can react with the functional groups added with crosslinking agents. When forming the membrane, it can react with the external adhesive to form a reticular membrane, so as to fix the villi on the base cloth.
Self crosslinking adhesives contain groups that make the molecular chain self crosslink, such as hydroxymethyl (-ch2-oh), epoxy (-ch- CH2), and also have a hydroxymethyl acrylamide (ch2=ch-conhch2oh) or epoxy propyl methacrylate (ch2= c-cooch2-ch- CH2) that can participate in copolymerization with other monomers to open the double bond to participate in the reaction.