Plastic PS Injection Molding Process Settings
Polystyrene (PS)
Heating Temperature:
Barrel temperature feeding zone: 30～50°C (50°C)
Zone 1: 160 ~ 250 ° C (200 ° C)
Zone 2: 200 ~ 300 ° C (210 ° C)
Zone 3: 220 ~ 300 ° C (230 ° C)
Zone 4: 220～300°C (230°C)
District 5: 220 ~ 300 ° C (230 ° C)
Nozzle: 220 ~ 300 ° C (230 ° 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.
Melt temperature: 220 ~ 280 ° C
Barrel constant temperature: 220 ° C
Mold temperature: 15 ~ 50 ° C
Injection pressure: has good flow performance, avoiding excessive injection pressure of 80 ~ 140MPa (800 ~ 1400bar)
Holding pressure: 30% to 60% of injection pressure; relatively short holding time
Back pressure: 5～10MPa (50～100bar); in the place where the back pressure is too low, bubbles are easily generated in the melt (there are gray and black lines in the product)
Injection speed: generally faster, multi-stage injection is based on the shape of the product; for thin-walled packaging containers should be as fast as possible, if necessary, using accumulators
Screw speed: high screw speed (maximum line speed of 1.3m / s) is allowed; but for good results, the plasticizing process should be slow as the cooling time
Metering stroke: 0.5 ~ 4D (minimum ~ maximum); 4D metering stroke is very important to provide a long enough residence time for the melt
Residual material amount: 2~8mm, depending on metering stroke and screw speed
Pre-bake: no need; if the storage conditions are not good, dry at 80 ° C for 1 h
Recovery rate: 100% recycling
Shrinkage: 0.3% to 0.6%
Gate system: point gate; heated hot runner, insulated hot runner, inner casting sleeve; relatively small cross section is sufficient
Machine downtime: no special cleaning work with other materials; PS temperature rise
Barrel equipment: standard screw, straight-through nozzle, check valve
