View source for Operations of making silicone mold


Step One: Take 100g of part A and add 2g of part B and mix the silicone rubber and curing agent evenly. 
Notes: Moulding silicon rubber is a kind of flowing liquid and it contains two parts. Part A is a kind of white flowing liquid and part B is the curing agent. Remember to mix part A and part B evenly, otherwise the silicon rubber will be partly solidified and this will give birth to difficulties in your final operation. What’s more, the finished moulds will meet a short life. All of these will cause a waste of silicon rubber.

Step Two: vacuum pumping
Without exception, this step takes less than 10 minutes. Otherwise, it will cause cross linking reaction, and no more further steps will be available. 


Step Three: Brushing cast & Perfusion Molding operation

Brushing cast: 
a. Evenly brush the mixed silicon rubber on the product which is covered with mold spray with a brush or a brush pen. 
b. After the cross linking reaction (about 30 minutes), brush a second coat which can increase the tension and tear strength of the mold. 
c. Cover a glass cloth on it after another 30 minutes of a second cross linking reaction, and use a brush pen or a brush to avoid any interstices.
d. Cover a third coat.
(Note: if you have high requirements for the tension and the tear strength for the mold, please repeat step c and step d. Hence, the finished silicone moulds will have a good quality and a longer life, which can help you save cost and increase production efficiency.)


Perfusion moulding:
It is suitable for simple products with the smooth surface.Without any mold lines,which helps you save time and is easy for operation.Evenly and slowly perfuse the mixed silicone rubber into the square fram.After the cross linking reaction and the silicone rubber turns dry,you can take the products out.Thus,the mold has been done.
(Note:we usaully use soft silicone rubber to make molds by perfusing,which is easy for demoulding and will not damage the product in the silicone molds.)


Operations for the external mold
a. Make a square frame with four pieces of wooden boards or rubber plates, then place the product which is covered with the finished silicon rubber mould in the middle.
b. Slowly and evenly perfuse the gypsum into the square frame. Also you can brush the resin on the product which is covered with the finished silicon rubber mould with a brush or a brush pen. Repeat this process two or three time after the cross link reaction.