Common knowledge about silicone rubber
159 2023-07-17

1. Why do silicone rubber molds have fewer times of mold flipping?

During the process of making the mold, too much silicone oil was added, which damaged the molecular weight of the silicone, resulting in the mold being less frequently flipped and less durable. If we make small products with complex patterns and use high hardness silicone to open the mold, there will be a phenomenon of fewer mold flipping times, because the silicone will be brittle and easy to break when it is too hard. On the contrary, if we use silicone with low hardness to make molds for building products, the results will also be unsatisfactory. Because silicone is too soft, its tensile and tear strength will decrease, and the resulting mold will deform, resulting in a decrease in the number of mold turns. The quality of the mold silicone itself is very good, and there is no distinction between good and bad silicone, only suitable and unsuitable. To avoid this situation, it is necessary to use silicone that is suitable for the hardness of the product to make the mold.

2. Why does the phenomenon of mold burning occur in silicone rubber molds?

Due to the addition of peroxide curing agents to unsaturated resins and resin products, a large amount of heat will be generated when encountering resin reactions. Generally, the resin curing time is 3 minutes. Therefore, it is necessary to demould as soon as possible after 3 minutes to prevent the silicone mold from burning.

3. Why does silicone rubber in molds exhibit a phenomenon of dry surface and dry interior?

Mold silicone is a type of condensed silicone that solidifies by absorbing water from the air. During the production process, the silicone evaporates the water dry without adding an appropriate amount of water, resulting in a phenomenon of non drying on the surface and inside. Solution: This phenomenon is not a product quality issue, but rather occurs due to the lack of control over moisture, improving the storage life of silicone, and ensuring a long shelf life. As long as 0.05% moisture is added appropriately and stirred evenly when using silicone, some problems can be solved.

4. Why does silicone rubber in molds exhibit poor tensile strength?

Because customers add a large amount of silicone oil to the silicone gel in order to reduce its viscosity and make it easy to operate during the mold production process, this will make the silicone gel very soft, resulting in poor tensile resistance, reduced tear strength, and decreased tensile strength, resulting in the mold being not durable, with short service life, and fewer mold turns.

5. Why does silicone rubber in the mold experience oil leakage?

The silica gel of the mold itself will not emit oil, which is due to the addition of composite silicone oil (a compound of silicone oil and white mineral oil) during the operation, because white mineral oil is a Petrochemical, not silicone oil.

6. Why does the mold exhibit a lack of resistance to acid, alkali, and aging?

During the process of making silicone molds, it is recommended that customers do not add any silicone oil. If necessary, the maximum amount of silicone oil added should not exceed 5% to 10%. Because excessive addition of silicone oil can damage the molecular weight of silicone, resulting in molds that are not resistant to acid, alkali, or aging.