Comprehensive analysis of solid-state hot pressing vulcanization molding: the core manufacturing process of silicone products

What is solid state hot pressing vulcanization molding?

Hot Compression Molding is a process that uses high temperature and high pressure to press solid silicone raw materials into shape. This process relies on the precise design of the mold and the temperature control system of the equipment. The silicone raw material with vulcanizing agent is placed in the mold and cross-linked by heat to obtain the final product shape.

Detailed explanation of process flow

1. Rubber mixing:
   • Silicone raw materials are milky white block solids at the beginning, and vulcanizers need to be added for cross-linking modification. If there are special requirements, such as adding masterbatch, luminous powder, fluorescent powder, conductive particles, etc., they should also be added. All ingredients are mixed in the rubber mixer for about 30 minutes to ensure that the ingredients are evenly distributed.
2. Cutting and waking up:
   • After the rubber mixing is completed, the rubber needs to be cut according to the product specifications and left to stand for about 8 hours. The surface of the rubber is covered with PE film to ensure its cleanliness. Waking up is to release internal stress and improve molding stability.
3. Hot pressing molding:
   • The awakened rubber is placed in the mold, and after the mold is closed, heating, exhaust, and pressure holding are performed on the hot pressing molding machine. This stage is the key to determining the product’s dimensional accuracy, structural integrity and performance.
4. Preliminary inspection and trimming:
   • The molded product needs to undergo the first round of inspection, including checking for dirt, missing edges, cracks, and insufficient maturity. Qualified products enter the edge removal process to remove burrs to ensure the appearance quality of the product.
5. Post-processing:
   • If the customer has customized requirements, such as surface spraying, silk screen printing, laser engraving and other processes, they can be completed at this stage.
6. Final inspection and packaging:
   • All products must be fully inspected again before packaging to ensure that no defective products enter the market. The packaging must meet customer requirements and be convenient for transportation and sales.

Advantages of solid hot pressing vulcanization

• High precision: mold forming, small dimensional error.
• High yield rate: reduce defective products through parameter setting control.
• Strong customizability: flexible formula to meet various functional requirements.
• Good cost control: suitable for medium and large batch stable production.

Scope of application

This process is widely used in the production of silicone mobile phone cases, silicone baby products (pacifiers, bibs), silicone kitchen utensils (cake molds, shovels), medical device gaskets, etc.

Conclusion

In the manufacture of silicone products, solid-state hot pressing vulcanization process has become one of the mainstream molding methods due to its maturity and stability. Precise control of process parameters and continuous optimization of mold design are the core of improving product quality and market competitiveness.