PA66 (polyamide 66 or nylon 66). Compared with PA6, PA66 is more widely used in the automotive industry, instrument housings, and other products that require impact resistance and high strength.What are the characteristics of PA66 plastic?

PA66 plastic has a higher melting point in polyamide materials. It is a semi-crystalline-crystalline material. PA66 can also maintain strong strength and stiffness at higher temperatures. PA66 plastic is still hygroscopic after molding, and its degree mainly depends on the material composition, wall thickness and environmental conditions. In product design, the influence of hygroscopicity on geometric stability must be considered. PA66 plastic has low viscosity and therefore has good fluidity (but not as good as PA6). This property can be used to process very thin components. Its viscosity is sensitive to temperature changes. The shrinkage of PA66 is between 1% and 2%. Adding glass fiber additives can reduce the shrinkage to 0.2% to 1%. The difference between the shrinkage rate in the flow direction and the direction perpendicular to the flow direction is large. The thermal melting point of PA66 plastic is the temperature at which the crystal melts. It shows a clear melting point for crystalline polymer PA66 plastic. According to the test method used, the melting point fluctuates within the range of 259 ~ 267 ° C. Generally, the melting point of PA66 plastic measured by differential thermal analysis is 264 ° C. If the temperature at which the volume expansion coefficient shows the maximum value is taken as the melting point, the melting temperature range of nylon-66 is 246 to 263 ° C. It is close to the theoretical melting temperature of 259 ° C. PA66 plastic injection characteristics drying treatment: if the material is sealed before processing, then there is no need to dry. However, if the storage container is opened, it is recommended to dry in 85C hot air. If the humidity is greater than 0.2%, it is necessary to perform vacuum drying at 105C for 12 hours.

PA66 plastic raw material is translucent or opaque milky white crystalline polymer with plasticity. The density is 1.15g / cm3. Melting point is 252 ° C. Embrittlement temperature is -30 ° C. Thermal decomposition temperature is greater than 350 ° C. Continuous heat resistance of 80-120 ℃, equilibrium water absorption of 2.5%. Resistant to acids, alkalis, most inorganic salt solutions, haloalkanes, hydrocarbons, esters, ketones, etc., but easily tolerated by polar solvents such as phenol and formic acid. Has excellent abrasion resistance, self-lubricating, and high mechanical strength. But it has a large water absorption, so its dimensional stability is poor.
PA66 plastic is the highest mechanical strength and most widely used variety in the PA series. Because of its high crystallinity, it has high rigidity and heat resistance.