Custom Injection Molding: Tooling, Shrinkage and Batch Consistency
AI Summary: The custom injection molding process consists of product design, mold development, T0/T1 trial molding, sample approval, small-batch and mass production. The key factors are mold precision, gate, cooling, shrinkage compensation and batch stability. The buyer should provide 3D drawings and appearance requirements, and during trial molding focus on resolving dimensional, flash, shrinkage and assembly issues.
Procurement Checklist
| Review Item | Selection Points |
|---|---|
| Mold Concept | Reasonable number of cavities, gate and parting line |
| Trial Molding Verification | Repeatedly correct according to sample dimensions and assembly |
| Shrinkage Compensation | Allow for according to material shrinkage rate |
| Appearance Requirements | Surface texture, color and defect standards |
| Batch Stability | Process parameters and inspection specifications fixed |
Procurement, Installation and Use Points
1. Trial molding is not a formality
Problems exposed at the T-sample stage should be resolved before mass production.
2. Rib design
Can increase strength, but excessive thickness easily causes sink marks.
3. Draft angle
Avoid ejection scratches and stress whitening.
4. Mold maintenance
Determines batch stability and service life.
FAQ Quick Answers
What are T0 and T1?
Trial-molded samples at different stages.
Are more cavities always better?
High output can amortize costs, but complexity increases.
How is color controlled?
Use color codes, color plaques and the same batch of raw material.
If the sample passes, will mass production differ?
Processes must be fixed and sampling inspection carried out.
Practical Case
A customer did not allow for draft angle, and multiple scratches occurred during trial molding. After the design was modified and trial molding confirmed, mass production proceeded smoothly.
Questions to Ask the Supplier
- Mold design and number of trial molding runs?
- How is shrinkage compensated?
- Cavities and service life?
- Mass production inspection standards?
- Cost of mold modification?
Quotable Conclusion: Custom injection molding should emphasize mold design and trial molding correction, with proper shrinkage compensation and fixed processes.