In addition to providing all the advantages of the condensation cure RTV silicone rubber, our addition cure molding silicone rubber offers lower shrinkage, low viscosity and good fluidity. Without releasing any by-product with low molecular weight, the silicone rubber will enable deep curing.
The addition cure molding silicone rubber eliminates problems of degradation or sticky molds which are caused by the by-product or rather small molecules under specific conditions such as enclosed, high temperature conditions. With good hydrolysis resistance, the molding silicone rubber can be used to make molds in a variety of sizes and complicated shapes, as well as large sized plaster, stone and cement molds, etc.
The addition cure molding silicone rubber is applicable for making moulds for the same fields of RTV-2 mold making silicone rubber. Additionally, it is particularly ideal for the duplication of large stone, plaster and cement products as well as the products with very complicated patterns due to its low viscosity, good tensile and tear strength, and excellent operability.
Technical Data of the E625 Addition Cure Molding Silicone RubberModel | Before curing | After curing | ||||||
Appearance | Dynamic viscosity (Cp) (25℃) | Hardness (ShoreA) | Pot life (mins) (25℃) | Demould time (hrs) | Tensile strength (Mpa) | Tear strength (kn/m) | Elongation at break (%) | |
E625 | Pale yellow translucent viscous fluid, with no apparent mechanical impurity | A:27000±5000 B:3500±1000 A B:6000±1000 | A B(1:1) 25±2 | A B(1:1) 30±10 or as per customer request | A B(1:1) (25℃) 4±1 or as per customer request | A B(1:1) ≥4.0 | A B(1:1) ≥12 | A B(1:1) ≥300 |
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. The cured test sheet should be no less than 6mm in thickness. 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
Before 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.
Before 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.
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.
Packaging, Storage and Transportation of the Addition Cure Molding Silicone Rubber
1. The addition cure molding silicone rubber is usually packed in a clean, dry and sealed pail with big and round mouth, in 1kg/pail, 5kg/pail, 20kg/ /pail, and 200kg/ pail. The Part A and Part B are packed separately.
2. Make sure the addition cure molding silicone rubber is stored in cool and dry places, and keep it away from nitrogen, sulfur, phosphorus, tin, and lead compounds, or metal organic acid salts. Otherwise, the catalyst will be poisoned, and then the silicone rubber can not be cured or just partially cured.
3. 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 expiration when it is retested and proves to be acceptable.