We offer two main types of silicone rubbers: tin-cured (Supersil T-series) and platinum-cured (Supersil P-series).
1. Tin-Cure Silicone Rubber
SuperSil™ Tin-cured Silicone rubber is a two-component material that cures at room temperature through a condensation reaction. It’s a versatile RTV silicone elastomer that provides excellent tear strength, accurate detail reproduction, and long-lasting performance. It’s ideal for making molds for casting polyurethanes, epoxies, polyester resins, cement, wax, soap, plaster, and more. Tin-cured silicone is easy to mix, de-air, and cures on nearly any surface.
2. Platinum-Cure Silicone Rubber
Platinum-cured silicone, also known as addition-cure silicone, is a room-temperature curing silicone that produces flexible, high-strength molds. SuperSil™ Platinum-cured molds offer superior release properties, and no release agent is needed when casting most materials. Unlike tin-cured silicones, platinum-cured silicones do not shrink during curing and have a longer library life.
Comparison: Tin-Cured vs. Platinum-Cured Silicone Mold Rubbers
- Cure Type:
Tin-cured silicones (Supersil T-series) are condensation-cure systems, which shrink slightly (about 0.5%) during curing. Platinum-cured silicones (Supersil P-series) are addition-cure systems, which do not shrink. - Library Life:
Tin-cured silicones have a shorter library life (2 to 5 years) compared to platinum-cured silicones, which last longer. - Cost:
Tin-cured silicones are generally more cost-effective than platinum-cured silicones. - Material Sensitivity:
Platinum-cured silicones are more sensitive to certain materials, such as sulfur, tin compounds, and Bondo, and can suffer from cure inhibition (uncured surface material) more frequently than tin-cured silicones. - Mold Inhibition:
Cured tin silicone molds can inhibit some casting materials, including platinum-cured silicones and many polyurethane rubbers. - Safety:
Platinum-cured silicones are non-toxic, food-grade, and skin-safe, making them suitable for use in food and medical products.
Mold Making Materials Comparison
| Type | Advantages | Disadvantages | Casting Materials |
|---|---|---|---|
| Tin-Cured Silicone | High strength, cost-effective | Shrinks on cure (~0.3%), limited storage life, not food-grade | Most materials, especially resins, foams, plaster, wax, concrete, etc. |
| Platinum-Cured Silicone | No shrinkage on cure, long storage life, excellent chemical resistance, food-grade, skin-safe, simple 1:1 mix | Cure inhibition by some materials, slightly more expensive than tin-cure | Most materials, resins, foams, plaster, wax, concrete, low-melt metals, and food-grade products |