PP plastics forming and use
April 15, 2022
Drying process conditions for injection molding: if stored properly, no drying is required.
Melting temperature: 220~275°C, please be careful not to exceed 275°C.
Mold temperature. 40~80°C, 50°C recommended. The degree of crystallisation is mainly determined by the mould temperature.
Injection pressure: up to 1800 bar.
Injection speed: In general, high speed injection can be used to reduce internal pressure. If the product has surface defects.
Then use a lower injection speed at a higher temperature.
Runners and gates.
For cold runners, typical runner diameters are between 4 and 7 mm. Rounded inlets and runners are recommended. All types of gates can be used. Typical gate diameters are between 1 and 1.5 mm, but gates as small as 0.7 mm can also be used.
For edge gates, the minimum gate depth should be half the wall thickness; the minimum gate width should be at least twice the wall thickness.
Hot runner systems are perfectly suited for PP materials.
Typical applications are in the automotive industry (mainly PP with metal additives: fenders, vent pipes, fans, etc.), apparatus (dishwasher door liners, dryer vents, washing machine frames and lids, fridge door liners, etc.), consumer goods (lawn and garden equipment such as lawn mowers and sprinklers, etc.).