The addition cure molding silicone rubber covers all the advantages of RTV silicone rubber, and additionally, it offers advantages such as lower shrinkage, low viscosity and good fluidity. Also, it has better curing performance as it doesn't release any low molecular weight by-product which may cause problems of degradation or sticky of molds at high temperature conditions.
With good hydrolysis resistance, low viscosity, good tensile and tear strength, and excellent operability, the molding silicone rubber can be used to make a variety of molds in different sizes and complicated shapes. It is especially suitable for duplication of large stone, plaster and cement products as well as the products with very complicated patterns.
Model | Before curing | After curing | ||||||
Appearance | Dynamic viscosity (Cp) (25℃) | Hardness (Shore A) | Pot life (mins) (25℃) | Demould time (hrs) | Tensile strength (Mpa) | Tear strength (kn/m) | Elongation at break (%) | |
E635 | Yellowish translucent fluid without apparent mechanical impurity | A:30000±8000 B:6000±2000 A B:10000±30000 | A B(1:1) 35±2 | A B(1:1) 30±10 or as per customer request | A B(1:1) (25℃) 3±1 or as per customer request | A B(1:1) ≥4.0 | A B(1:1) ≥7 | A B(1:1) ≥200 |
1. Keep sample at room temperature for at least one hour before you take a proper amount of it for testing. Put A and B under room temperature for one hour respectively, and then mix them evenly in the ratio 1:1. Test the viscosity immediately. (For the fast cured type addition cure molding silicone rubber, delayed action activator is required.) 2. Thickness of the cured test sheet should be no less than 6mm. 3. Mix A and B evenly at a ratio of 1:1 under room temperature, and record the time when crosslinking reaction occurs in the mixture. 4. The test sheet is initially vulcanized with the thickness at least 2cm, and it can be restored after extrusion. The cured sheet is made to offer standard mechanical property, which is tested by an electronic universal testing machine. |
Note
1. For the testing of pot life, component A and B should be mixed uniformly at the ratio of 10:1 under room temperature. The pot life refers to the time duration from the mixing of component A and B starts to crosslinking occurs in the mixture.
2. For demould time testing, component A and B have to mixed evenly in a ratio of 10:1 and then pour the mixture into the aluminum alloy mold; After that, deair it with a vacuum machine, and finally put it into the oven (100℃) until it is cured totally.
3. For dynamic viscosity testing, the component A and component B should be put at room temperature for at least one hour respectively, and then mix them completely in the ratio 10:1. Test the viscosity immediately after the component A and B are mixed. For the fast cured type silicone rubber, delayed action activator is required.
Storage, Package and Transportation of the Addition Cure Molding Silicone Rubber
We recommend storing the addition cure molding silicone rubber in cool and dry places, and keep it away from nitrogen, sulfur, phosphorus, tin, and lead compounds, or metal organic acid salts to ensure superior curing performance.
Our addition cure molding silicone rubber is packed in a clean, dry and sealed pail with big and round mouth, in 1kg/pail, 5kg/pail, 20kg/ /pail, and 200kg/ pail. The component A and B are separately packed.
The silicone rubber is NOT subject to the provisions of the IMDG code. It has a shelf life of 18 months from the date of production, but it can still be used after the shelf life if it is retested and proves to be usable.