| Detail | For this role |
|---|---|
| Department | Production |
| Level | Entry level |
| Reports to | Production Supervisor |
| Direct reports | None |
| Experience | 1 to 3 years on injection moulding machines |
Injection Moulding Operator job description template
Copy this job description, replace the text in square brackets and post it on your careers page or a job portal.
Job title: Injection Moulding Operator
Department: Production
Reports to: Production Supervisor
Location: [City], [office, branch or site]
About the role
An Injection Moulding Operator runs plastic injection moulding machines. They load the material, monitor the moulding cycle, remove parts, trim flash and gates, and check each shot for short fill, sink or flash. The role reports to the Production Supervisor or Shift In-Charge. A good moulding operator keeps the cycle stable and parts within quality limits, catches process drift early, and supports quick, clean mould changeovers.
Key responsibilities
- Load the correct plastic granules and any masterbatch into the hopper and set the drier if needed.
- Start the machine on the set process parameters and confirm the first shots meet the approved sample.
- Remove moulded parts each cycle, and trim flash, gates and runners without damaging the part.
- Check every shot or at the set frequency for short fill, sink marks, flash, weld lines and warpage.
- Segregate defective shots, log the reason, and call the supervisor when a defect repeats.
- Watch the cycle time, melt and mould temperature and pressure, and report any drift from set values.
- Support mould changeover by cleaning, staging inserts and helping the setter, then run the first-off.
- Weigh and pack good parts to the standard count and label the boxes correctly.
- Keep the machine, mould face and area clean, and manage runners and regrind as instructed.
- Record output, rejection and downtime on the machine log through the shift.
Requirements
- ITI or tenth pass with plastics training
- CIPET moulding course is an advantage
- Ability to read a process parameter sheet
- 1 to 3 years on injection moulding machines
KRAs and KPIs for a Injection Moulding Operator
Key result areas for the appraisal form, each with a KPI you can measure every month or quarter.
| Key result area | How to measure it |
|---|---|
| Rejection control | Moulding rejection from short shot, flash or sink below the machine target each month |
| Cycle stability | Cycle time held within the set range so the shift quantity is met |
| Changeover support | First-off after changeover approved within the target time on most changes |
| Packing accuracy | Box count and labelling correct on at least 99 percent of packed cartons |
| Material use | Granule and regrind consumption kept within the standard per thousand parts |
| Safety | No burn or guard-related incident recorded on the machine in the month |
Skills and tools
Tools used day to day: Injection moulding machine, Mould and inserts, Side cutter and trimmer, Weighing scale, Hopper drier.
Reporting line and career path
Next roles: Moulding Setter, Process Technician, Production Supervisor
Interview questions for a Injection Moulding Operator
- What causes a short shot and how do you correct it on the machine?
- Why does material need drying before moulding some plastics?
- How do you tell flash apart from a normal parting line on a part?
- What do you check on the first-off part after a mould changeover?
- How do you handle hot moulds and nozzles safely during the shift?
- Tell me about a time the cycle drifted and how you spotted it.
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Book a free demoSee pricingFrequently asked questions
What does an injection moulding operator do?
An injection moulding operator runs plastic moulding machines. They load material, run the cycle on set parameters, remove parts, trim flash and gates, and check each shot for short fill, sink and flash. They keep the cycle stable, segregate defects, support mould changeovers, and pack good parts to the standard count.
What is a short shot in injection moulding?
A short shot is a moulded part that is not fully filled, so it comes out incomplete. It can be caused by low injection pressure, cold melt, blocked gates or too little material. The operator spots it during checks, segregates the part, and reports the drift so the setter can correct the process.
What qualifications do you need to be an injection moulding operator?
Most injection moulding operators hold an ITI or a tenth pass, and a plastics or CIPET course is a strong advantage. Employers train operators on the machine and process sheet. The key skills are reading parameters, spotting moulding defects, trimming parts cleanly, and working safely around hot moulds and nozzles.