Nylon is the trade name of polyamide fiber, also known as nylon. The focused structure of nylon is closely related to the stretching and heat treatment during the spinning process. Nylon molecules spun at normal spinning speeds are prone to crystallization, which occurs during the spinning process. Due to the inconsistent internal and external temperatures during cooling forming, the outer layer of nylon generally has a higher degree of orientation and lower crystallinity, while the core layer has a higher degree of crystallinity and lower orientation. The main chains of different nylon macromolecules are connected by carbon and nitrogen atoms. The number of atoms attached to carbon and nitrogen atoms is very small, and there are no side groups present, so the molecule forms an extended planar sawtooth shape.
The main physical and chemical properties of nylon:
1. The longitudinal surface of nylon is straight and smooth, with a circular cross-section. Nylon is alkali resistant but not acid resistant. In inorganic acids, the amide bonds on nylon macromolecules will break;
2. Strong stretchability and wear resistance Nylon has high strength, large elongation, excellent elasticity, and a fracture strength of about 42-56cN/tex, with a fracture elongation of 25% -65%. Therefore, nylon has particularly excellent wear resistance, ranking first among common textile fibers. It is an ideal material for making wear-resistant wiping products. However, nylon has a small initial modulus, is prone to deformation, and its fabric is not stiff;
3. Moisture absorption and dyeing properties: Nylon has good moisture absorption among common synthetic fibers, with a moisture regain of about 4-5% under general atmospheric conditions; In addition, nylon has good dyeing properties and can be dyed with acid dyes, dispersed dyes, and other dyes;
4. Due to the sensitivity of the end groups of nylon macromolecules to light and heat, nylon turns yellow and becomes brittle, resulting in poor light and heat resistance. Therefore, it is not suitable for making outdoor fabrics. In addition, nylon is corrosion-resistant, not afraid of mold, and not afraid of insect infestation.
Due to its non-toxic, lightweight, good wear resistance, and excellent corrosion resistance, nylon yarn is widely used in civilian applications to produce blended products and improve the durability of fabrics. Nylon yarn has strong vitality, and various fabrics woven from nylon yarn have the characteristics of smooth and durable feel. Widely used in civilian applications for processing socks and other blended products to improve the durability of fabrics.