1. RTV Silicone Rubber for gypsum/concrete molding usages
RTV Silicone Rubber for gypsum/concrete molding is primarily intended for mold making of gypsum, concrete, poly resin ,PU resin, unsaturated resin crafts, lighting and candles crafts , plastic toys , stationery gifts crafts industry, large statue, Buddha, relievo furniture, furniture decorative materials, statues Buddha, artifacts copied, building decoration materials, large-scale cement mold, artificial fossils Factory, European buildings, simulation landscapes, animals and plants sculpture, sandstone crafts and so on.
2. RTV Silicone Rubber for gypsum/concrete molding main features
RTV Silicone Rubber for gypsum/concrete molding is white or red flowing liquid with general hardness of 22-50 shore A ,after curing. Molding silicon rubber is a kind elastic silicon rubber mold which features with resistance to deformation, high-temperature, acid-alkali and expansion as well as high reproduction times, good tensile strength ,tear strength and elongation.
3. RTV Silicone Rubber for gypsum/concrete molding discription
RTV Silicone Rubber for gypsum/concrete molding is a kind of flowable liquid silicone, the quality has nothing to do with the color. It consists of two components. Part A is a flowable liquid silicone rubber, part B is the curing agent. Firstly, after your previous work of dealing with the original model, take some liquid silicone rubber , add 2%-3% curing agent of the amount of silicon, and mix them evenly. Then after vacuum-pumping the mixture, you can pour it into the mold frame. The silicone mold will cured in 2-4 hours.
And more curing agent is needed; contrarily, if molds requiring slower drying and demould, less curing agent is needed.
4.Datasheet of RTV Silicone Rubber for gypsum/concrete molding
| Model | Color | Mixing ratio (%) | Operation Time (mins) | Demould | Hardness ( A0 ) | Tensile-strength (MPa) | Tear-strength (kN/m) | Dynamic Viscosity | Shrinkage | Elongation |
| time | (mPa.s) | rate (%) | (%) | |||||||
| ( hrs) | ||||||||||
| 615# | white | 100:3 | 30-50 | 4-5 | 15±2 | 2.5 | 16±2 | 13000±2000 | ≤0.3 | 380 |
| 620# | white | 100:3 | 30-50 | 4-5 | 20±2 | 2.8 | 19±2 | 17000±2000 | ≤0.3 | 530 |
| 625# | white/translucent | 100:3 | 30-40 | 3-4 | 25±2 | 3.4 | 24±2 | 25000±2000 | ≤0.3 | 410 |
| 630# | white/translucent | 100:3 | 30-40 | 3-4 | 30±2 | 4.0 | 26±2 | 27000±2000 | ≤0.3 | 420 |
| 638# | white/translucent | 100:3 | 30-40 | 3-4 | 38±2 | 4.0 | 25±2 | 25000±2000 | ≤0.3 | 450 |
| 640# | white/translucent | 100:3 | 30-50 | 4-5 | 40±2 | 3.5 | 21±2 | 15000±2000 | ≤0.3 | 180 |
5. RTV Silicone Rubber for gypsum/concrete molding frequently asked question
Why does the silicone mold appear to be dry outside but wet inside?
Because molding silicone rubber is a kind of condensation silicone rubber, which get solidified after absorbing moisture from the air. In order to provide a significant shelf-life for the silicon rubber, we will dry out the water in the silicon rubber.
Solution: Add 0.05% water into the silicon rubber and Stir over a low speed briefly when you use it.
Any more information, pls feel free to contact Christy