An oven rubber or oven seal ensures that the seal between the oven door and heated oven compartment is airtight. The name oven rubber is confusing because these seals are made of silicone. Silicone is being used in ovens because it is functional at extremely high and extremely low temperatures.
Follow this link for the assortment of silicone profiles for the use in ovens, proving ovens etc.
Silicone profiles can be ordered per metre or on a roll. Silicone cannot be welded like PVC because of the material properties. This is why it is glued together with professional silicon glue (article 8.03.03-0).