Choosing an injection molding machine requires matching clamp force, shot size, injection capability, mold fit, temperature control, repeatability, and automation to the part and process. Tonnage alone does not prove that a machine can make a stable part.
Check the machine-to-mold fit
- Confirm clamp force from projected cavity and runner area and the expected cavity pressure.
- Check mold height, daylight, tie-bar spacing, platen size, locating ring, ejector stroke, and core-pull interfaces.
- Compare shot size, screw diameter, injection rate, pressure, recovery time, and residence time with the resin and part.
Match control to quality risk
- Review barrel and mold-temperature control, pressure and speed resolution, cushion stability, sensors, and calibration.
- For precision or optical parts, consider repeatability, data capture, cavity pressure monitoring, and environmental control.
- For TPU or other sensitive materials, confirm screw geometry, purging, drying, low-shear handling, and residence-time limits.
Validate the real setup
Use the actual mold, resin, cavity count, cycle, and acceptance criteria in the machine selection. A machine that is much too large can create poor shot utilization and residence-time risk; one that is too small can limit pressure, clamp capacity, or process stability.
Plan the next step
Share your part, resin, annual volume, critical dimensions, finish, and timing with the Cavity Mold team through our contact page. We can review the manufacturing risks and recommend a practical next step.
Related Cavity Mold resources
- Injection mold engineering services
- Plastic injection molding services
- Injection mold making services
- Contact Cavity Mold
Technical references
- Autodesk Moldflow clamp force calculation
- ARBURG injection molding equipment
- Keyence injection molding formulas
Match the machine to the complete process
A machine is suitable only when its clamp, injection, plasticizing, mold-space, control, and safety ranges support the actual part and mold. Selecting by tonnage alone can hide a shot, fit, or process limitation.
| Decision | What to check | Boundary |
|---|---|---|
| Clamp and projected area | Estimate projected area, cavity pressure assumption, safety margin, and parting risk. | Use a calculation as a screening step, then validate the actual mold. |
| Shot and plasticizing | Check shot volume, cushion, recovery, residence, screw, and material behavior. | Keep the shot within a stable control range for the chosen grade. |
| Injection capability | Review rate, pressure, gate, flow length, thin features, and packing demand. | A large clamp does not guarantee the required filling behavior. |
| Mold fit and controls | Check platen, tie bars, daylight, ejection, cooling, sensors, and recipe control. | The mold must fit and be controllable, not merely close. |
Machine-fit review
- Freeze part, material, cavity, and mold inputs.
- Screen clamp and shot requirements.
- Verify fit and injection capability on the target machine.
- Record the margin and the condition that invalidates the choice.
Use engineering review before committing equipment, then align the production process with the machine-fit RFQ.