Introduction of Liquid Silicone Rubber for Molding
RTV-2 Silicone Rubber is a kind of two-component material. The RTV-2 silicone rubber is made up of Part A base silicone and Part B curing agent. The Part A base silicone and Part B CA curing agent can cure at room temperature by a condensation reaction, after full cure, it become a cured silicone mold. The silicone mold can be cast the following materials for reproduction: plaster, polyurethane, PU, GRC, cement, resin, polyester, wax etc...
Applications of Liquid Silicone Rubber for Molding
MC RTV-2 silicone rubber for mold making can be used in the filed of reproducing cement molds, concrete stones, artificial stones, plaster molding, figures, art objects, decoration molding, GRC products, gypsum products, resin products, PU molds. Etc.+
Data of Liquid Silicone Rubber for Molding
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%
Instruction for making RTV-2 silicone rubber 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 35℃ (95℉).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 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.
Storage of Liquid Silicone Rubber for Molding
When the silicone rubber is stored at or below 30 ℃ (85 ℉) in the original unopened containers, RTV2 Silicone Base and CA30 Curing agent have a usable life of 12 months from the date of production. After 12 months, please use a stirring mill to stir the Part A silicone for some minutes, then the silicone can be use again, without any influence to the characteristics.
Packing of Liquid Silicone Rubber for Molding
Part A base silicone: 20kg/drum, 25kg/drum or 200kg/drum
Part B CA30 Curing Agent: 0.25kg/bottle,1kg/bottle and 10kg/bottle |
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