PA process characteristics(2)

Before processing PA12 polyamide 12 or nylon 12, the humidity should be below 0.1%. If the material is stored in air, it is recommended to dry in 85C hot air for 4~5 hours. If the material is stored in a closed container, it can be used directly after 3 hours of temperature equilibrium. The melting temperature is 240~300C; for ordinary characteristic materials, do not exceed 310C, and for materials with flame retardant properties, do not exceed 270C.

　　 Mold temperature: 30~40C for unreinforced materials, 80~90C for thin-walled or large area components, and 90~100C for reinforced materials. Increasing the temperature will increase the crystallinity of the material. Precise control of mold temperature is very important for PA12. Injection pressure: up to 1000 bar (recommend to use low holding pressure and high melting temperature). Injection speed: high speed (better for materials with glass additives).

　　 runner and gate: For the material without additives, due to the low viscosity of the material, the runner diameter should be about 30mm. For reinforced materials, a large runner diameter of 5 to 8 mm is required. The shape of the runner should be all round. The inlet should be as short as possible.

　　 Various gates can be used. Do not use small gates for large plastic parts, this is to avoid excessive pressure on the plastic parts or excessive shrinkage. The gate thickness is preferably equal to the thickness of the plastic part. If a submerged gate is used, the minimum diameter is recommended to be 0.8mm. Hot runner molds are effective, but require precise temperature control to prevent material leakage or solidification at the nozzle. If a hot runner is used, the gate size should be smaller than the cold runner.