Common Problems in Silicone Mold Prototypes (Vacuum Casting)
By NICE Rapid | Jan 17 , 2020

1. Less mold turnover

Too much silicone oil was added in the process of making the mold. The silicone oil destroyed the molecular weight of the silicone, so the mold would have less turnover and less durability. There would be exist less mold turnover phenomenon if use high hard silicone mold to copy small and complicated products with pattern. The silicone mold would become brittle after a long time cold down, it is very easy to get broken. Conversely, the products would be broken easily if use more soft silicone mold to copy big and hard products.

2. Burnout mold phenomena

Because unsaturated resins and resin products are added with peroxide curing agents, a large amount of heat is generated when they react with the resin. Generally, the curing time of the resin is 3 minutes. Therefore, the mold must be released as soon as possible after 3 minutes to prevent the silicone mold from Burning phenomenon occurs.

3. Have the phenomenon of dry on surface and moist on internal

Mold silicone is a kind of condensation type silicone, it is solidified by absorbing water in the air. During the process of making silicone mold, the water is evaporated to dryness without the proper amount of water being added, which caused the silicone mold with dry surface and moist on internal.

4. Have poor pull

In the process of making the mold, in order to reduce the viscosity of silicone and make it easy to handle, a large amount of silicone oil will be added to silicone. This will make silicone become very soft, cause resistance to tearing, reduce tear strength, and decrease the tensile force. As a result, the mold is not durable, the service life is short, and the number of mold turning times is small.

5. The silicone mold has poor sour alkali resistance and ageing resistance

In the process of making silicone molds, we suggest do not add any silicone oil. If necessary, the amount of silicone oil should not exceed 5% to 10%. Because the amount of silicone oil added too much will destroy the molecular weight of silicone, which caused the mold has poor sour alkali resistance and ageing resistance.

6. The silicone molds with tool mark, scratch and not smooth surface

In fact, the model or product itself is not smooth or perfect. If the product or model to be copied hasn’t been polished, even the best silicone mold will be unattractive and not smooth enough.

There is another case, it is the applied of release agent, when it is not be brushed well-proportioned, the mold is not smooth as well.

If you are interested in silicone mold products, please feel free to contact us at to get free quotes or proposal for your projects. We will be your best counselor!

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