Precautions in the Silicone Mold Making Process
Silicone molds are widely used in various fields such as industrial production and handicrafts due to their flexibility, heat resistance, and ease of demolding. However, the process of making silicone molds is not straightforward; it involves several key steps and precautions. This article provides a detailed overview of the important considerations during the silicone mold-making process:
1. Mold Design
Parting Line Design: Design the parting line based on the shape and size of the product to ensure the mold can open and close smoothly, avoiding misalignment errors during molding.
Draft Angle: Design an appropriate draft angle to allow the product to be easily removed from the mold, reducing damage and residue.
2. Preparing the Master Model
Choose suitable materials for the master model, such as wood, plastic, metal, or 3D printing materials. Ensure the model surface is smooth and defect-free to produce a high-quality silicone mold.
3. Constructing the Mold Frame
Accurately construct the mold frame according to the mold design dimensions. The mold frame is generally rectangular or square, but for parts with special structures, the frame can be built to match the shape to save silicone.
When building the silicone mold frame, ensure there is enough space between the four walls, the bottom, and the edge of the RP (Rapid Prototyping) model (e.g., 20mm). The height of the side baffles should be appropriate (e.g., RP model height + 90mm) to prevent silicone from overflowing during degassing.
4. Selecting and Mixing Silicone Materials
Choose the appropriate silicone material, such as Room Temperature Vulcanizing (RTV) silicone rubber or High-Temperature Vulcanizing (HTV) silicone rubber. Mix the silicone and curing agent evenly according to the specified ratio, taking care to avoid the formation of bubbles.
5. Vacuuming and Curing
Place the mixed silicone into a vacuum chamber for degassing to remove bubbles and ensure the quality of the mold.
Pour the degassed silicone into the mold frame, covering the master model. Allow the silicone to cure based on its type and the ambient temperature, ensuring it fully solidifies.
6. Demolding and Finishing
After the silicone has cured, carefully disassemble the mold frame and remove the master model. Inspect the silicone mold for defects and make any necessary adjustments, such as removing burrs and polishing the surface.
7. Usage and Maintenance
When using silicone molds, avoid sharp objects that could scratch the mold surface. Clean the mold promptly after use and store it properly to extend its lifespan.