What Affects the Tear Strength of Mold-Making Silicone?

What Affects the Tear Strength of Mold-Making Silicone?

Several factors influence the tear strength of cured silicone rubber.

Silicone formulation: Polymer structure, reinforcing fillers, cross

linking chemistry, and other formulation choices can significantly affect tear resistance.

Curing conditions: The silicone's mixing ratio, mixing quality, curing temperature, and curing time should follow the manufacturer's recommendations. Incorrect processing may lead to inferior mechanical properties.

Silicone hardness: Hardness can influence tear performance, but the relationship is not universal. Two silicones with the same Shore A hardness may have different tear strength values.

Mold design: Thin walls, sharp internal corners, narrow openings, and deep undercuts can concentrate stress and increase the risk of tearing.

Demolding technique: Pulling a casting out too aggressively or in the wrong direction can damage even a high-performance silicone mold.