Customers buy all sorts of silicone rubber gaskets. In fact, silicone rubber gasketing materials are some of our most popular materials we sell to customers. Of course, theres all sorts of silicone rubber materials. Customers sometimes ask if one is better than the other. The answer is, (everyones favorite) IT DEPENDS ON THE APPLICATION!
First things first. What is Platinum, and What is Peroxide?
These are two different types of curatives, or chemical additives that are added to a silicone rubber compound. Each functions in a different way to “cure” the rubber to make it solid, and elastic- this process is called vulcanization. Most silicone rubber materials are cured via heat. Each curative offers different properties, along with different benefits, and drawbacks. TYPICALLY, when NEDC manufactures silicone rubber gaskets, they are platinum cured.
Platinum Cured Silicone Rubber (addition cure)
-Typically great elongation, tear, and tensile properties
-Cleaner finish, i.e clearer colors, translucent, clear, white
-Used for FDA(food, and beverage)/USP applications
-Shorter shelf life compound
-Generally most expensive than peroxide cured counterparts
-No byproducts as a result of the process
Peroxide Cured Silicone Rubber
-Blooming can occur (a white crystalline powder rising to the surface, a byproduct)
-Usually better compression set properties
-Post Cure to bake off additional volatiles left over by the peroxide curative required.
-Longer shelf life compound
-Requires talc to be processed
-Generally cheaper than platinum cured counterparts
-Lower temperature to cure