The silicone that is platinum cured is far harder to process than peroxide-cured silicone. This is because it requires extremely high temperatures in order to be cured.
Peroxide-cured silicone rubber on the other hand has a long shelf life because once it has been mixed it can be stored for long periods of time.
What is the curing process of platinum-cured silicone?
Curing is the process by which an elastomer becomes cross-linked. In the case of platinum-cured silicone, platinum is added to the silicone as a catalyst. This then causes the crosslinking of the polymer chain with itself.
Pros of platinum cured silicone
- Platinum cured silicone is visually more transparent, making it brilliant for applications where the user needs a clear silicone material.
- Platinum silicone has better elongation, high tear strength, tensile strength, and low shrinkage, this means that they are the perfect material to use in applications such as gaskets, silicone tubing, and moulds. Platinum’s also have both application and physical properties that other rubbers do not
- Does not require the use of talc in processing.
- Considered to be the cleaner of the two silicone types and are used frequently in the food, pharmaceutical, and automotive industries as they are non-yellowing and have zero peroxide by-products.
Cons of platinum cured silicone
- It is more expensive to produce than peroxide-cured silicone
- There is more scrapped material during the production process. This is because once the catalyst is added to the silicone compound, the material will begin to cure.
- Platinum-cured silicone is harder to process as it requires higher temperatures to start the curing systems.
What is the curing process of peroxide-cured silicone?
In peroxide-cured silicone, peroxide is broken down by high temperatures which crosslink the polymers in the chain.
Pros of peroxide-cured silicone
- Peroxide silicone products have a longer shelf life.
- It is a cheaper material to produce than platinum silicone. This means that silicone extrusions like rubber tubing and silicone sheeting can be sold at more competitive prices.
- It is easy to process and can be cured at lower temperatures as they have a lesser tolerance to heat.
- The curing process will improve the compression set performance of peroxide-cured silicone rubber.
Cons of peroxide-cured silicone
- Peroxide-cured silicone can stick to itself in production and post-curing, especially in softer grades (grade list can be found on our datasheet).
- Peroxide-cured silicone is not as transparent as platinum-cured silicone. It is also more translucent in appearance.
Viking Extrusions Supply both peroxide and platinum cured grades of silicone. If you are unsure about which grade you require for your application, please contact one of our experienced technical advisors who will be happy to assist you.