Description of RTV-2 Liquid Silicone Rubber for Gypsum Casting
Gypsum Mold Making Silicone Rubber is a two-component material, this kind of silicone rubber consists of Part A base silicone and Part B CA30 curing agent, and Part A base silicone and Part B curing agent can cure at room temperature by a condensation reaction. These materials can be cast into the cured silicone molds: Plaster polyurethane, PU, GRC, cement, resin, polyester, wax etc...
Features of RTV-2 Liquid Silicone Rubber for Gypsum Casting
1. Good flowability and long working time
2. Medium hardness
3. High tear and tensile strength
4. Easy de-mould from complex replica parts
5. Acid and alkali-resistance
6. Low linear shrinkage
Applications of RTV-2 Liquid Silicone Rubber for Gypsum Casting
RTV2028 silicone rubber is suitablr for gypsum mold making.
How to make the silicone mold?
1. Preparing
The surface of the original objects should be clean and free of loose material. If your products have thin flower patterns, and especially have porous substrates, please use a suitable mold release agent such as soap water, detergent, Vaseline or petroleum jelly.
2. Mixing
Please weigh Part A silicone base and part B CA30 Curing Agent with ratio of 100: 2 into a clean container. Stir Part A base silicone thoroughly before use, then Mix Part A and Part B evenly until the curing agent completely dispersed in the silicone base. Manual or mechanical mixture can be used, but do not last much time or allow the temperature to exceed 35C (95F). It's suitable to mix small quantities to ensure thorough mixture of silicone base and curing agent.
Note: It is strongly recommended that entrapped air be removed in a vacuum chamber, allowing the mixture to completely expand and then collapse. After a further 1 to 2 minutes under vacuum, the mixture should be inspected and can be used if free of air bubbles. A volume increase of 3-5 times will occur on vacuum de-airing the mixture. So a suitably large container should be chosen.
3. Pouring the mixture and curing
Pour the mixed Part A base silicone and CA-30 curing agent as soon as possible onto the original object, avoiding air entrapment. The catalyzed material will cure to a flexible rubber within 6 hours (or faster by different mixing ratio or room temperature), we advice you de-mold after 24 hours, it is will improve the replicate times of silicone mold.
Packing of RTV-2 Liquid Silicone Rubber for Gypsum Casting
Part A base silicone: 20kg/drum, 25kg/drum or 200kg/drum
Part B CA30 Curing Agent: 0.25kg/bottle, 1kg/bottle and 10kg/bottle
Storage of RTV-2 Liquid Silicone Rubber for Gypsum Casting
When the RTV-2 silicone rubber is stored at or below 30 C (85F) in the original unopened containers, Silicone Base and CA30 Curing agent have a usable life of 12 months from the date of production.
Note of RTV-2 Liquid Silicone Rubber for Gypsum Casting
RTV2028 silicone rubber is an industrial product and must not be used in food molding, dental human skin molding applications.
| Item |
RTV 2028 |
| Color |
off-white |
| Curing agent |
CA30 |
| Mixing ratio |
100:2 |
| Mixed viscosity |
28000~30000 cps |
| Working time |
30-40 mins |
| Curing time |
4-6 Hours |
| Hardness |
27-28 Shore A |
| Tear Strength |
30 N/mm |
| Tensile Strength |
4.5 Mpa |
| Shrinkage |
≤0.3% |
| Relative density |
1.11~1.15g/cm3 |
| Elongation at break |
511% |
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