Silicone rubber mold manufacturing method and precautions
The silicone rubber mold is one of the simplest methods in rapid mold.
Generally, the RP prototype is re-molded with silicone, but life is very short only about 10-30 pieces! It has good elasticity and replication performance. The silicone rubber replication mold does not need to consider the draft slope, does not affect the dimensional accuracy, has a good division, and can be directly cast as a whole without dividing the upper and lower molds. Then cut along the predetermined parting line and take out the master mold!
Room temperature vulcanized silicone rubber mold is divided into two types, addition molding, and condensation type.
The raw material and formula are made of special-purpose silicone rubber mold. The molded product is sold in double packaging. Part A is a rubber compound and Part B is a catalyst. When preparing, the room temperature, strength, and hardness of the rubber 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 component B by 0.1-0.3 parts. If the room temperature is too high, it will decrease by 0.1-0.3 copies of Group B.
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 in 2 hours at room temperature of 20 degrees and can be used after one day.
Precautions for making silicone rubber molds
- Component B is a catalyst and is susceptible to moisture and hydrolysis, so the cover should be tightly closed after use.
- The chemical reactions of Groups A and B begin immediately after mixing. The viscosity gradually rises and cannot be stopped.
In order to avoid waste, it should be used as needed according to the dosage. It should be used immediately after preparation, without delay.
- The mixing ratio of groups A and B is related to the speed of the 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, the toughness decreases. Therefore, weighing requires precision.
- Before preparation, the component A material should be stirred up and down, and then weighed.
- The die 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, and 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
- Improve the design of the flash tank and exhaust system
- Increase the pressure of the press
- Reduce the amount of release agent and spray evenly
- Material controls moisture
- You can try to add some antifoam
- Use cold runner
- Vacuuming with a vacuum machine can increase the exhaust operation on the mold.
Please contact DGMF Mold Clamps Co., Ltd for the mold components, thank you.
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