Vacuum casting (cast urethanes) is a commonly used rapid prototyping technology, when low volume of a 3D CAD model are required. The parts are made out of Polyurethane which has properties close to real injected plastics, such as ABS, PC, PA, POM, PA, PP, TPE's or TPR rubbers etc. Usually, a series of 5-100 pieces will be run using this casting technology. Each Silicone mould can make a maximum of 20 to 25 pieces.
As the current commonly way to make prototype are CNC machining and 3d printing, so not too many people know the silicone fast mold. The following is the production process of silicone rapid die.
1. the production of prototype: in the production of silicone mold before the mold, you must first make a prototype, the prototype can be done with CNC machining or 3d printing.
2. the preparation of materials: A component is the compound, B component is the catalyst, room temperature at 20-25 degrees, A: B = 100: 1.5. When the room temperature is low (but not less than 10 degrees) increase the B component 0.1-0.3 copies. When room temperature is high, reduce the B group 0.1-0.3 copies.
3. the production of mold: put the prototype into the corresponding container, pour the mixed materials into, at room temperature of 20 degrees under 2 hours can be cured into elastomer, one day later will be usable. At this time only need to take out the rapid silicone mold, and then cut along the predetermined parting line to remove the prototype.
After the silicone mold, you can use silicone mold to copy prototypes with other plastic materials (such as abs, pc, acrylic, etc.)