One of the greatest problems facing many small-scale mould makers is air bubbles within their silicone mould. The bubbles inside the silicone rubber mould itself are generally not much of a serious issue. The issue is if the air bubbles form on the casting surface making the mould unusable.
There are numerous ways to use to make certain bubble free silicone moulds:
1) Special pouring techniques
2) Applying compressed air
3) Using Vacuum to eliminate bubbles
4) Using pressure to force air into solution
The top where casting materials meet silicone moulds is the most important part. It really is therefore necessary that additional care is offered to make certain no bubbles form when pouring the silicone rubber in to the mould box and on the model. It is crucial to never simply pour the rubber over the top of the model in one go. Begin by pouring a small amount of rubber in the mould box and start tilting it in several angles to make the rubber slide over-all surfaces. This wets the top of the model with a fine film of rubber as well as air bubbles can easily be seen and popped using a pin or paint brush.
You can even use a paint brush to use this first fine film of rubber for the surface of the model. Select the method which works for your chocolate silicone mold.
When you are satisfied that most the bubbles happen to be popped you are able to pour the other mould making rubber in the mould box. Pour from as high a point as possible within a fine stream to ensure any bubbles inside the mixture will pop about the way down. Aim this stream into the corner of the mould box and never along with the model.
If you have use of an aura compressor you possess an effective way of popping air bubbles. Ensure you have about 30psi pressure along with a small nozzle tip and after pouring the 1st tiny amount of rubber in the mould box blow the information across the model to wet the surface within a similar way to the initial method. The very first film of rubber must be bubble free.
Bubbles tend to be a consequence of air beaten in to the rubber through the mixing process. Ensure you stir the mixture inside a steady and slow action. There is still air from the mixture however and this could be removed through the help of a vacuum chamber.
These vacuum chambers utilize a vacuum to suck out any air bubbles in the mixture and bring them to the outer lining where they may be easily removed. Each vacuum chamber has their particular 41dexfpky on the way to make use of it but the following is a guide:
1) Work with an oversized container for mixing. Enable the mixture to double in proportion when placed into the chamber.
2) Mix both part A and part B in the container and place in to the chamber. Close the chamber and start the vacuum pump.
3) The mixture will begin rising to the peak of your container. All the air bubbles from the mixture will rise to the surface. Since the mixture approaches the top of the the container release the valve which breaks the vacuum as well as the mixture will drop for the bottom as well as the air bubbles will pop. Do that 2-3 times to make sure all bubbles are removed.
4) Release the vacuum one final time and take the mixture from the chamber. It can be now ready for pouring.
Using a vacuum chamber is normally only easy for cake rolling pin which require a fair period of time to create. A number of the quicker setting silicone rubbers sets too rapidly so you won’t have the time and energy to vacuum the bubbles out. Make sure you look at the label around the product you might be using.