Injection moulding machine
Also called: IMM, plastic injection machine, injection molding machine, clamping force, moulding machine
An injection moulding machine melts plastic pellets in a heated barrel and injects them under high pressure into a closed steel mould, then cools and ejects the part. Its size is given by clamping force (tonnes) and shot weight, which must match the mould and the part.
Quick facts
- Size
- Clamping force in tonnes (e.g. 50–1000 t) and shot weight in grams
- Drive
- Hydraulic, all-electric or hybrid
- Cycle
- Close, inject, hold, cool, open, eject: seconds to a minute
- Materials
- PP, ABS, nylon, PC, POM and most thermoplastics
- Needs
- A mould made for the part
- Extras
- Robots, hot runners, mould temperature controllers
Matching the mould to the machine
- Clamping force must exceed the plastic's pressure on the projected area of the part and runners
- Shot weight capacity should comfortably exceed the part plus runner weight
- The mould must fit between the tie bars and within the daylight (opening)
- Moulders check these when you share the part and mould details
Hydraulic or electric?
- Hydraulic: lower cost, strong clamping, common in Indian job shops
- All-electric: faster, more precise and energy saving; cleaner for medical and electronics parts
Need work done on a Injection moulding machine?
Post your requirement free. Workshops that take your kind of work see it and get in touch. You only talk to the ones that fit.
Get startedRelated
Related job work
Questions
- What does 100 tonne mean on an injection moulding machine?
- The clamping force that holds the mould closed during injection: 100 tonnes.
- How do I know what machine size my part needs?
- It depends on the part's projected area, wall thickness, plastic and shot weight. Share the 3D model and plastic grade and the moulder will choose the machine.
The figures on this page are typical values for guidance, written by Diemeco from standard engineering practice. They are not a specification: confirm grades and properties with the relevant standard or the supplier's mill test certificate, and tolerances with your workshop. Last checked 8 October 2026.