Plastic injection
Plastic injection — mass production with a mould
Plastic injection is a mass-production method in which molten thermoplastic is forced at high pressure into a closed mould and shaped as it cools.
How it works
Plastic granules are heated and melted by a screw and injected into the mould cavity. Once the part cools and hardens, the mould opens and the part is ejected. At high volumes the cost per part drops rapidly.
Key properties
- High volume in one run with repeatable quality.
- Mould cost is high; it is amortised at high volumes.
- Wide geometry freedom (threads, snaps, shells).
- High colour and material variety.
- Mould design and process setup are critical.
Use cases
- Mass-produced consumer parts
- Boxes, caps and housings
- Technical and automotive parts
- Moving from a 3D printed prototype to mass production
Compatible materials
ABSPC/ABSPPPEPA (nylon)POMPMMA (acrylic)TPE/TPUGlass-fibre reinforced grades
Frequently asked questions
When do you switch to injection?
Usually from hundreds/thousands of units onward; the mould cost is amortised at that volume and the cost per part becomes lower than 3D printing.
How long does a mould take?
Simple moulds can be produced in a few weeks; complex, multi-cavity moulds take longer.
Which materials are used?
ABS, PP, PE, PA, POM, PC/ABS and glass-fibre reinforced thermoplastics are common; the choice depends on strength and service conditions.