mold making silicon rubber

Features of mold making silicon rubber

1. Good characteristics of easy-operation

2. Ligh viscosity and good flowability

3. Low shrinkage

4. Favorable tension

5. No deformation

6. High temperature resistance, acid and alkali-resistance and ageing resistance

Operation Instruction for mold making silicon rubber:

(1)  Correct mixing ratio

Component A is silicone rubber, and component B is curing agent or vulcanizing agent, usually the mixing ratio  will be 2-3%.

(2) Preparation of the Original molds

Firstly, you should deal carefully with the Original mold or the products you want to be molded.  

(3)Vacuum-Pumping Process

To mix the silicone and catalyst with a standard mixing ratio and then do the process of Vacuum-Pumping. Bubbles will come out during the mixing of the silicone and hardener, if without Vacuum-Pumping, the bubbles cannot be released from the mixture, as a result, there will be many bubbles in the finished silicone mold. Then the mold has a less tensile strength which will affect the reproduction times. Such an unsmoothed silicone mold will affect the quality of the production directly.

 Brushing cast for mold making silicon rubber:

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.

FAQ:Why should the mold making silicon rubber mold be reused only for a few times?

It can be due to the following reasons:

a. Adding too much silicone oil in to silicon rubber. Silicon oil is an additive which destroies the molecular weight of silicone rubber and reduce the tension and tear strength.

b. Using the silicon rubber with a high hardness to make molds for small sized products with delicate and intricate designs and the silicon rubber with a low hardness to makes molds for large sized products with simple designs.

(Notes: we should choose the silicon rubber specifically according to the requirements of our products to avoid this problem.)

For getting further information about mold making silicon rubber, PLS contact with Miss Caroline:

Tel: +86-755-89948019

Mobile: +86-18938867567

Skype: cathy19900719

Email: hysf(at)szrl(dot)net

Website : www(dot)szrl(dot)net