Why do some secondary vulcanization silicone rubber after molding, products will go
Silicone rubber products believes everyone not unfamiliar, some products through moulding process can directly use after coming out, and some products also need to undertake secondary sulfide (
Have called secondary plus sulfur)
Actually forming after we seems to have been a good product from the naked eye, why the secondary sulfide can be normal use?
First of all, to be sure, not all need silica gel secondary vulcanization silicone rubber products, only depending on the formulation of raw materials, some of them are a molding can directly, but some special materials such as fluorine rubber products, some of the EPDM is the need for secondary vulcanization silicone rubber products, it is because the first of these materials in a sulfide, the inside of the peroxide decompose polymer reaction, to produce some low molecular compounds (
Such as benzene, benzoic acid, etc. )
, these low molecular compounds can reduce the mechanical properties of silicone rubber in rubber life is reduced, but also are poisonous.
This is very adverse to silicone meal kitchen utensils and appliances, so common secondary vulcanization silicone rubber products manufacturer will evaporate low molecular compound.
Second, in a sulfide is finished, the silicone molecule may not fully crosslinking (
, make its vulcanization silicone rubber secondary sulfide can more fully and more evenly, so as to improve the mechanical properties of rubber and durable.
Third, carries on the silicone secondary sulfide, such as a large number of use on the car of the EPD can freshen up after the second vulcanization silicone rubber products, improve the vehicle occupant comfort.
Fourth, silicone products manufacturer wholesale to reduce costs, increase production capacity, often shortened silicone curing time for the first time, and then in prolonged secondary sulfide, ensure product fully sulfide at the same time, also improve their competitiveness.