Plastic PA6 Injection Molding Process Settings
Barrel temperature:
Feeding area 60～90°C (70°C)
Zone 1 230 to 240 ° C (240 ° C)
Zone 2 230 to 240 ° C (240 ° C)
Zone 3 240 ~ 250 ° C (250 ° C)
Zone 4 240 ~ 250 ° C (250 ° C)
Zone 5 240 ~ 250 ° C (250 ° C)
Nozzle 230 ~ 240 ° C (250 ° C)
The temperature in parentheses is recommended as the basic set value, the stroke utilization is 35% and 65%, and the ratio of module flow length to wall thickness is 50:1 to 100:1.
Feed zone and zone 1 temperature directly affect feed efficiency, increasing these temperatures can make feed more even
Melt temperature: 240 ~ 250 ° C
Barrel constant temperature: 220 ° C
Mold temperature: 60 ~ 100 ° C
Injection pressure: 100 ~ 160MPa (1000 ~ 1600bar), if you are processing thin section long channel products (such as wire tie), you need to reach 180MPa (1800bar)
Holding pressure: 50% of the injection pressure; due to the relatively fast condensing of the material, a short holding time is sufficient. Reduce the pressure of the pressure to reduce the stress inside the product
Back pressure: 2～8MPa (20～80bar), need to be adjusted accurately, because the back pressure is too high, it will cause uneven plasticization.
Injection speed: It is recommended to use a relatively fast injection speed; the mold has good ventilation or the coking phenomenon is easy on the product.
Screw speed: high screw speed, line speed is 1m / s; however, it is best to set the screw speed to a lower point, as long as the plasticization process can be completed before the end of the cooling time; lower screw torque is required
Measuring stroke: 0.5 ~ 3.5D
Residual material amount: 2~6mm depends on metering stroke and screw diameter
Pre-baking: drying at 80 ° C for 4 h, except that it is directly fed from the charging container; nylon is water-absorbent and should be stored in a moisture-proof container and a closed hopper; a water content of more than 0.25% will cause a molding change.
Recovery rate: 10% return material can be added
Shrinkage: 0.7% to 2.0%; or 30% glass fiber, shrinkage is 0.3% to 0.8%; if the temperature is more than 60 °C, the product should be gradually cooled; gradually cooling can reduce shrinkage after molding, ie The product exhibits better dimensional stability and small internal stress; steam method is recommended; nylon products can be inspected by welding fluid
Gate system: point type, latent type, chip type and sprue can be used; blind hole and gate socket are recommended to break the cold point; hot runner can be used; because the melt can be processed in a narrow temperature range, the hot runner should be Provide closed loop temperature control
Machine downtime: no need to clean with other materials; the melt remains in the barrel for up to 20min, after which thermal degradation is easy to occur
Barrel equipment: standard screw, high plasticizing capacity for special geometry; anti-reverse ring, straight-through nozzle; for the addition of glass fiber reinforcement, high wear-resistant bimetallic barrel
