Delivery Lead Time:
7 days
Packaging:
Buckets for 500g,1kg,5kg.
Drums for 20kg,25kg,200kg.
Payment Terms:
- Credit Card
- PayPal
- Check
- Western Union
- T/T
- L/C
Minimum Order:
200 Kilogram
Supply Availability:
500 Ton per Month
Product Description
Product Description
Specification
Condensation Cured Silicone Rubber for Mold Making, which is also named condensed cure silicone rubber and Tin cure silicone rubber, is
generally industrial liquid silicone rubber vulcanized under room temperatureRTV-2.
Applications
Condensation Cured Silicone Rubber has extensive use,such as mold making of gypsum,plaster,concrete,cement,flowerpot,candle,soap,resin
crafts,cultural stone,sculpture,GRC/GRG restoration and so on.
Techinical Parameters
Model Code GTSIL-T10 GTSIL-T15 GTSIL-T20 GTSIL-T25 GTSIL-T30 GTSIL-T40
Hardness - Shore A 8-10 14-16 19-21 24-26 28-32 38-40
Viscosity - Cps 10000-14000 12000-16000 14000-18000 16000-20000 26000-32000 10000-14000
Mixing Ratio - % 3% 3% 3% 3% 3% 3%
Tear Strength - KN/m2 10-15 15-18 19-23 23-27 25-30 16-20
Tensile Strength - Mpa 3.5-5.5 3.5-5.5 4-6 4-6 5-7 3.5-5.5
Shrinkage - % 0.30% 0.30% 0.30% 0.30% 0.30% 0.30%
Elongation - % 400-500% 400-500% 400-500% 400-500% 350-500% 350-500%
How to use
1.Substrate Preparation
The surface of the original should be clean and free of loose material. If necessary, and in particular with porous substrates, use a suitable release agent such as petroleum jelly or soap solution.
2. Mixing
Thoroughly stir Part A silicone base before use as filler separation may occur upon prolonged storage.
Weigh 100 grams Part A silicone base and 3 grams Part B curing agent in a clean container. Mix together until the curing agent is completely dispersed in the base. Hand or mechanical mixing can be used, but do not mix for an extended period of time or allow the temperature to exceed 35°C 95°F. Mix suitably small quantities to ensure thorough mixing of the par A silicone base and part B curing agent.
It is strongly recommended that entrapped air be removed in a vacuum chamber, allowing the mix to completely expand and then collapse. After a further 1-2 minutes under vacuum, the mix 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.
Caution: prolonged vacuum will remove volatile components from the mix and may result in poor thick section cure and non-typical properties.
Note: If no vacuum de-airing equipment is available, air entrapment can be minimized by mixing a small quantity of par A silicone base and part B curing agent, then using a brush, painting the original with a 1-2mm layer. Leave at room temperature until the surface is bubble free and the layer has begun to cure. Mix a further quantity of base and curing agent and proceed as follows to produce a final mold.
3. Pouring the Mixture and Curing
Pour the mixed Par A silicone base and Part B curing agent as soon as possible onto the original, avoiding air entrapment. The catalyzed material will cure to a flexible rubber within 24 hours at room temperature 22°C-24°C/ 71.6°F - 75.2°F and the mold can then be separated from the original. If the working temperature is significantly lower, the cure time will be longer. If the room temperature or humidity is very high, the working time of the catalyzed mixture will be reduced. The final mechanical properties of the mold will be reached within 7 days.
ADDITIONAL INFORMATION
Reproduction of Vertical Surfaces
If a skin mold is required of a vertical object or surface and cannot be made by normal pouring techniques, the catalyzed mixture can be made non flowable by the addition of thixotropic agent.
1. Prepare the original as described earlier.
2. Brush the original with a thin layer of catalyzed mixture. Repeat the operation when the first layer has started to cure, to achieve a coating thickness of 2mm. Leave to cure at room temperature until the material is tacky.
3. Prepare a new catalyzed mixture of silicone and add 1% by weight of thixotropic additive and mix thoroughly until a paste consistency is reached. De-airing of the mixture is not required.
4. Using a spatula, cover the coated original with the thixotropic coating until all undercuts are filled; leave to cure for 24 hours at room temperature.
5. Construct a support mold using polyester resin or plaster and allow to set in contact with the silicone coating. Carefully remove the support mold. Peel the rubber off the original and place in the support mold.
Use at High Temperatures
Some molds produced from condensation cure silicone rubbers can degrade when exposed to temperatures above 150°C 302°F over a period of time or when totally confined in storage at high ambient temperatures. This can result in softening and loss of elastic properties.
