If your silicone mold becomes brittle and cracks after only a short period of use, the common causes can generally be attributed to five key areas: material selection, curing process, operating environment, handling practices, and mold design.

1. Insufficient Tear Strength of the Material. For products with fine, intricate patterns, a high-strength, tear-resistant silicone should be selected to extend mold life. Hardness selection is also critical: if the hardness is too high, the mold becomes brittle and prone to cracking; if too low, the mold lacks deformation resistance and wears out quickly.

2. Incomplete Curing or Skipping Post-Cure. After demolding, the silicone is only initially set; the internal cross-linking reaction is not yet fully complete. If the post-cure step is skipped, the mold's final physical properties—tear resistance, resilience, and heat resistance—will not reach their optimal levels, significantly shortening service life.

3. Excessive Exotherm from Casting Materials (Concrete/Resin/Plaster). When producing concrete, resin, or plaster products, the heat released inside the mold repeatedly attacks the silicone molecular chains, causing the mold surface layer to age, turn white, become brittle, and powder. For frequent casting of concrete or thick resin parts, a silicone grade with better heat resistance is recommended.

4. Improper Handling Practices. If the mold is not given adequate "recovery time" between each casting cycle, continuous high-frequency use will accelerate fatigue aging. It is advisable to allow a rest interval between uses to let the mold regain its elasticity.

5. Mold Design Issues. Complex geometries—thin walls, deep undercuts, and sharp corners—concentrate stress during demolding, making the mold more susceptible to damage. Such molds should, where possible, incorporate smooth transitions or include reinforced thickness in vulnerable areas. If the product itself is inherently complex, selecting a high-tear-strength silicone is recommended to compensate for structural weaknesses.

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