Introduction to the classification of nylon (PA) plastics

Polyamide commonly known as nylon (Nylon), English name Polyamide (referred to as PA), is a molecular backbone containing repeating amide groups—[NHCO]—Generic term for thermoplastic resins. Including aliphatic PA, fat— Aromatic PA and Aromatic PA. Among them, aliphatic PA has many varieties, large output and wide application, and its name is determined by the specific number of carbon atoms of the synthetic monomer. The main varieties of nylon are nylon 6 and nylon 66, which are absolutely dominant, followed by nylon 11, nylon 12, nylon 610, nylon 612, and nylon 1010, nylon 46, nylon 7, nylon 9, nylon 13, new There are nylon 6I, nylon 9T and special nylon MXD6 (barrier resin), etc. There are many kinds of modified nylon, such as reinforced nylon, monomer casting nylon (MC nylon), reaction injection molding (RIM) nylon, aromatic nylon , transparent nylon, high impact (super tough) nylon, electroplated nylon, conductive nylon, flame retardant nylon, nylon and other polymer blends and alloys, etc., to meet different special requirements, widely used as metal, wood and other traditional materials replacement Supplies, as various structural materials. Nylon is the most important engineering plastic, and its output ranks first among the five general engineering plastics. Performance: Nylon is a tough angular translucent or milky white crystalline resin. As an engineering plastic, the molecular weight of nylon is generally 15,000-30,000. Nylon has high mechanical strength. , high softening point, heat resistance, low coefficient of friction, wear resistance, self-lubrication, shock absorption and noise reduction, oil resistance, weak acid resistance, alkali resistance and general solvent resistance, good electrical insulation, self-extinguishing, non-toxic, Odorless, good weather resistance, poor dyeability. The disadvantage is that the water absorption is large, which affects the dimensional stability and electrical properties. Fiber reinforcement can reduce the water absorption of the resin, so that it can work under high temperature and high humidity. Nylon has a very good affinity with glass fiber. Among nylons, nylon 66 has the highest hardness and rigidity, but the worst toughness. Various nylons are sorted according to their toughness: PA66＜PA66/6＜PA6＜PA610＜PA11＜PA12. The flammability of nylon is UL94v-2 grade, the oxygen index is 24-28, the decomposition temperature of nylon is >299℃, at 449 Spontaneous combustion occurs at ~499°C. Nylon has good melt fluidity, so the wall thickness of the product can be as small as 1mm.