4, melt temperature
It can be measured by air-jet method. 270-295 ℃ range, enhanced grade GF-PET can be set to 290-315 ℃ and so on. 5, injection speed
General injection speed to be fast, to prevent premature solidification when injected. But too fast, high shear rate of the material fragile. The shot is usually completed in 4 seconds. In this case,

6, back pressure
The lower the better, so as not to wear. Generally not more than 100bar. Usually not required. 7, retention time
Do not use excessive residence times to prevent molecular weight degradation. Try to avoid temperatures above 300 ℃. If the shutdown is less than 15 minutes. Only for the air shot treatment; if more than 15 minutes, will use the viscosity of PE clean, and the barrel temperature dropped to PE temperature, until the boot date. 8, attention to matters
⑴ recycling material can not be too large, otherwise easy to produce at the cutting Department "bridge" and the impact of plastics. In this case,
(2) If the mold temperature control is not good or material temperature control properly, easy to produce "white mist" and opaque. Mold temperature is low and uniform, cooling speed, less crystallization products transparent.

PS plastic (polystyrene)
English name olystyrene
Specific gravity: 1.05g / cm3 Molding shrinkage: 0.6-0.8% Molding temperature: 170-250 ℃ Drying conditions: --- Material properties Electrical insulation (especially high frequency insulation) Excellent colorless, transparent, light transmittance After the plexiglass, coloring of water resistance, good chemical stability. Strength in general, but the crisp, easy to produce stress brittle fracture, not benzene. Petrol and other organic solvents. Suitable for the production of insulating transparent pieces. Decorative pieces and chemical equipment Optical instruments and other parts.
Molding performance 1. Amorphous material, moisture absorption is small, do not need to fully dry, not easy to decompose, but the coefficient of thermal expansion, easy to produce internal stress. Mobility is better, can be screw or plunger injection molding machine.