Common Silicone Mold Problems
Silicone molds encounter problems during production. Understanding these helps improve mold performance.
| Problem | Symptoms | Causes |
|---|---|---|
| Bubbles | Visible holes, rough surface | Improper mixing, rapid pouring |
| Tearing | Rips at edges | Too soft silicone, thin walls |
| Demold difficulty | Product sticks | Deep undercut, no mold release |
| Surface defects | Rough finish | Pattern quality issues |
Bubbles: Causes and Solutions
| Cause | Solution |
|---|---|
| Rapid mixing | Mix Part A and B gently, circular motion |
| No degassing | Use vacuum chamber 3-5 minutes |
| Fast pouring | Pour slowly from 20cm (7.9 in) height |
| Complex pattern | Apply silicone to details with brush first |
Tearing: Causes and Solutions
| Cause | Solution |
|---|---|
| Silicone Shore A below 15 | Use Shore A 20-30 for thin sections |
| Wall below 3mm (0.1 in) | Minimum 3-5mm (0.1 in–0.2 in) thickness at edges |
| Complex undercut | Add mother mold support |
| Repeated stress | Modify design, add draft angle |
Demold Difficulty: Solutions
| Solution | Method |
|---|---|
| Mold release | Apply spray before each cast |
| Adjust hardness | Shore A 15-25 for complex shapes |
| Split mold design | Two-part for complex geometry |
| Polish pattern | Smooth surface reduces friction |
Preventive Checklist
| Check | Why Important |
|---|---|
| ✅ Correct hardness selection | Match Shore A to complexity |
| ✅ Smooth pattern preparation | Pattern determines mold quality |
| ✅ Slow mixing, proper ratio | Prevents bubbles and curing issues |
| ✅ Vacuum degassing | Removes trapped air |
| ✅ Test demold first | Identify problems early |
BKSilicone Quality Control
- Pattern inspection before mold making
- Silicone matched to application
- Vacuum degas all molds
- First cast test every mold
- Shore A verification
Related: Advantages guide, Materials guide, Custom service.
Need Help?
BKSilicone provides factory-direct support for silicone mold problems. Contact us for technical assistance.
