SI-Thinner is a water clear, low viscosity, non-reactive silicone fluid which can be added to either condensation cure (GI-Series) or addition cure (P-Series) silicone rubber. The maximum recommended amount that should be added is 15% by weight, based on the weight of the silicone rubber base.
When added to silicone rubber compounds, SI-Thinner changes the properties of the rubber in the following ways
Reduced Viscosity: Silicone rubber mixtures with 15% SI- Thinner will show much lower viscosity, enabling the rubber to more easily flow into intricately detailed areas.
Improved Air Release: The addition of of SI-Thinner allows air to escape from the silicone rubber more easily, leading to quicker, more efficient de-aeration.
Lower Durometer: SI-Thinner acts as a plasticizer when added to silicone rubber, producing a cured product that is softer and more flexible than the original compound.
Enhanced Release Properties: Silicone rubber compounds that have SI-Thinner added to them often show improved release properties, which allows parts to be easily removed from the mold.
Lower Tear Resistance: Silicone rubber RTV's that have been modified by the addition of SI-Thinner show some reduction in tear strength and tensile strength, while elongation is usually increased.
The decision to incorporate SI-Thinner into a silicone rubber system should be based on careful consideration of these advantages and disadvantages. Customers are encouraged to test various levels of SI-Thinner in their applications, and should use the lowest amount of SI-Thinner that produces the desired effect.