The method of operation of a silicone rubber mold

Mold silicone rubber is two-component RTV silicone rubber, usually before mold making, first check the silicone flowability, A component is a viscous liquid, white also color, but also according to user requirements, tune into each colors of liquid silicone, at room temperature about 25 degrees, the viscosity of the silica gel in general about 35000CPS, silica gel viscosity is too large, it will cause uneven mixing silicone curing agent, made out of the mold with dry uneven situation, the correct use Methods are:
1. silicone and curing agent according to a certain proportion of added standard ratio, the ratio of silica gel and the curing agent is 100: 2-100: 5, the greater the amount of curing agent, the curing time, the faster, shorter operation time, Appearance liquid silicone mold flow, A component is silica, component B is the curing agent. Example: Take 100 grams of silica gel, 2 g of curing agent (Note: silica gel and curing agent must stir, stir if not, there will be a mold has been cured, a not cured, dried and cured silicone will appear uneven situation, it will affect the life of the silicone mold and turning model number, or even result in scrapping the original model).
2. Vacuum row bubble treatment: silicone and curing agent stir, to be evacuated process, under normal circumstances, evacuation time should not be too long, under normal circumstances, not more than ten minutes, vacuum too long, silicone immediately curing, resulting in a crosslinking reaction, so that becomes a piece of silicone, can not insulate paint brush or perfusion, thus wasting silicone, only the silicone into the trash, do re-take the silica gel.
3. Brushing operating procedure: the smoked vacuum bubble row over silica gel, brushing or perfusion manner silicone pour the product above (Note: the product or model to be replicated before the fall silicone release agent or a release agent absolutely necessary ). Then put silicone in the product above brushing, brushing must be uniform, 30 minutes after pasting a layer of gauze or silica glass fiber cloth to increase the intensity and tension. Then brushing a layer of silica gel, and then paste a layer of gauze or glass fiber cloth, so after twice on it. Only by doing so, open up the silicone mold life and turning model number will relatively improve a lot, to be able to save costs and improve efficiency.
4. Outer mold production: The general approach is to die surrounded by plastic sheet or boarded up, one is surrounded with plaster mold, filled with plaster on it and another resin brushing way, the Tu brush on a layer of resin paste layer of glass fiber cloth, then brushing then paste, repeated two or three can be completed outside the mold of the mold.
5. Now lists a curing agent and a silica gel (silicone) ratio of reactions: One is the reaction of the company's drying and curing agent mixing ratio of silica gel
① curing agent plus an amount of 1%, 2.5 hours colloid is still flowing, 6-8 hours to release.
② curing agent plus 2%, 50-1 minutes glue will flow off, 2-3 hours to release.
③ curing agent plus 3%, 28-30 minutes colloid is still flowing, 1.5-2 hours to release.
④ curing agent plus 4%, 10-15 minutes colloid is still flowing, 1-1.5 hours to release (Note: Curing agent added the largest amount of not more than 5%, more than 5% hardener time too fast, not normal use, resulting silicone mold scrapped).