PC plastic material is widely used in lens mold, displayer molds or panel molds of home appliance and drawers molds of freezer. When making the mold design for PC part, we should know well about its injection molding features otherwise it is hard to deliver the qualified samples for customers' approval.
1, Preparation before injection:
Water absorption of PC plastic materials is
large, the PC ram material must be dry before injection, pure PC shoule be drying in 120 ℃, modified
PC Chips with a temperature of 110 ℃ dried for more than
4 hours. Drying time can not exceed 10 hours. Generally available air extrusion
method can determine whether the material is sufficient drying.
2, Injection molding machine selection:
PC plastic products due to cost and other
aspects, the use of modified materials, particularly electrical products,
should also increase the fire resistance, in the flame-retardant PC alloy
products and other plastic molding,plastics mixing system of injection molding machines required good resistance to corrosion, conventional
plasticizing screw is difficult to achieve, So, PC screw was suggested to make PC parts.Normally, we will use DAKUMAR Injection Machine PC screw injection machine.
3, Mold design and Injection gate location selection:
Common mold temperature of 80-100 ℃, with fiberglass
is 100-130 ℃, small articles can use point gate, and gate depth should be 70% of the
thickest parts. For freezer drawer molds, we will used hot runner valve gate, the hot runner system can be YUDO, HASKY,MOLDMASTER ...and of the other cold runner gate is edge gate or rectangular gate. Gate is bigger, the injection is better in order to reduce PC plastic flowing resistance through the gate. Air vent slots depth should be less than 0.03-0.06mm, the flow path as short and round,
draft angle is is generally about 30'-1.
4, Melt temperature:
General PC plastics processing temperature
of 270-320 ℃, some modified or low molecular weight PC plastic materials for the
230-270 ℃.
5. Injection speed:
Common with relatively fast speed injection
molding, like electrical switches , Slow - rapid forming.
Long residence time at high temperature in the injection machine barrel, the material will be degraded, put CO2, the material turns yellow.
Do not use LDPE, POM, ABS or PA clean up barrel, please use PS !
Hope the PC Plastics Application-Home Appliance Molds is useful for you, Sino Mould is good at design and manufacturing home appliance molds.
Posted by Joyce
Email: sino1508@sinomould.com
