Silicone Rubber MoUld Production Methods And Precautions

Mold technology: silicone rubber mold production methods and precautions

The rubber mold is one of the simplest methods in the rapid mold. Generally, the RP prototype is re-molded with silicone, but the life is very short, only about 10-30 pieces! It has very good elasticity and replication performance. With silicone rubber replication molds, it is not necessary to consider the draft slope, it will not affect the dimensional accuracy, and it has a good division. Then cut along the predetermined parting line and take out the master mold!

Room temperature vulcanized silicone rubber is divided into two types: addition molding and condensation type:

The raw materials and formulas are made of special mold silicone rubber. The product is sold in double packaging, with component A being rubber and component B being catalysts. When preparing, the room temperature, the strength and hardness of the mold should be considered to determine the weight ratio of the AB component.

When the room temperature is 20-25 degrees, A: B = 100: 1.5. When the room is low (but not less than 10 degrees), it is appropriate to increase the component B by 0.1-0.3 parts. If the room temperature is too high, the B group will be reduced by 0.1-0.3 parts. The specific method is to determine the total dosage according to the volume of the mold, and then weigh the components A and B accurately in a proportional manner, place them in a vessel and stir them evenly, and serve.

Molding: Pour the prepared material into the clean object to be copied. In order to save materials, thinner molds can also be applied in batches. To increase the tensile force of the mold, the gauze and the like can be pasted. It can be cured into an elastomer within 2 hours at room temperature of 20 degrees, and can be used after one day.

Precautions for making silicone rubber molds:

1. Component B is a catalyst, which is susceptible to moisture and hydrolysis, so the cover should be tightly closed after use.

2. Once A and B are mixed, the chemical reaction starts immediately. The viscosity gradually rises and cannot be stopped. In order to avoid waste, it should be used according to the dosage and used immediately after the preparation.

3. The mixing ratio of groups A and B is related to the speed of chemical reaction and the performance of the mold. The more component B, the faster the reaction, the higher the strength and hardness of the product, but the toughness decreases. Therefore, weighing requires precision.

4. Before preparation, the component A material should be stirred up and down, and then weighed.

5. The casting method is suitable for reliefs, and the brushing method is suitable for the production of three-dimensional molds. The mold for pouring relief should first make a frame with a length and width greater than the original length and width of 4-6CM. The frame should be straight and the inside should be smooth. When pouring, place the frame on a clean glass plate, then place the original in the frame, leaving a gap of 2-3CM on each side

There are air bubble solutions in the production process:

Improved design of flash tank and exhaust system

Increase the pressure of the press

Reduce the amount of release agent and spray evenly

Material control moisture

You can try to add some antifoam

Use cold runner

Vacuuming with a vacuum machine can increase the exhaust groove on the mold.