PMMA PC PET transparent parts molding technology

What's the difference between PET mould, PC mould? 

What should be paid attention to when injecting transparent parts 

separately in PMMA, PC and PET?

First let’s discuss about final product and plastic raw material issue.

1) Transparent parts do not quire any bubble,
flow mark or other quality problem that can influence transmittance. 

2) Raw material must be clean, need drying before injecting

3) Barrel and screw of injection machine should be clear, no any waste material 

4) Raw material plasticizing time not too long, if something emergency happen need to stop machine work, lower the material temperature. (PC, PMMA lower than 160℃, PET lower than 240℃)


And of course the most important is the molding technology, check below: 

1) Wall thickness of final products should be uniform,
height of thinnest part should no less than 1mm ( PET part can be little thinner)

2) The transition of different dimensions should be smooth 

3) Runner section should be large but short passway, 

  cavity and runner appearance should be smooth (surface roughness no large than 0.4um )

4) Make sure smooth air venting

5) Cold slug needed 

6) Back pressure of injection machine not too high 

7) Injecting pressure should be high, but should not too high to influence demoulding

8) Try low injection speed on the base of perfect fulfill mould cavity

9) Pressure keeping time and injection cycle time should not be too long 

10) To ensure final product’s appearance transparency, the less mould releasing the better

Lucia

focaremould@yahoo.com