Crossing the “non-stick” divide: The chemical art and evolution of additive liquid silicone primers

Crossing the Non-Stick Divide: The Chemical Art and Evolution of Mold Release for LSR

Mold release is one of the most challenging aspects of LSR molding. The inherent tackiness of silicone and its tendency to adhere to mold surfaces require sophisticated release strategies.

The Chemistry of Release:

LSR's adhesion to mold surfaces is influenced by its low surface energy, chemical affinity to metal oxides, and the mechanical interlocking at the micro-scale. Effective release requires overcoming these forces without damaging the part or the mold.

Release Strategies:

1. Internal Release Agents: Additives incorporated into the LSR formulation that bloom to the surface during curing, creating a release layer.

2. External Release Agents: Spray-on or wipe-on coatings applied to the mold surface between cycles.

3. Permanent Coatings: PTFE, ceramic, or DLC (diamond-like carbon) coatings applied to the mold surface for long-term release performance.

4. Mold Surface Engineering: High-polish finishes, specific textures, and surface treatments that minimize adhesion.