What is the hardening treatment method for liquid silicone products?
The hardening treatment of liquid silicone rubber (LSR) products usually refers to the process of transforming liquid silicone rubber into solid rubber through a specific process, which is called vulcanization. Here are some common methods for hardening liquid silicone gel:
Hot vulcanization:
After injecting liquid silicone into the mold, it is vulcanized by heating. This is the most common hardening method, which can be achieved through an oven or heating plate.
Room temperature vulcanization:
Some liquid silicone can be vulcanized through chemical reactions at room temperature, which is suitable for heat sensitive applications.
Platinum catalyzed sulfurization:
The sulfurization process using platinum as a catalyst can avoid the production of by-products and improve the transparency and purity of the product.
Double disulfide sulfide:
Using sulfur dioxide and hydrogen sulfide as sulfurizing agents is a low-cost method, but may produce some by-products.
UV or electron beam curing:
Some special formulations of liquid silicone can be rapidly cured by UV or electron beam irradiation.
Microwave vulcanization:
Heating silicone gel with microwave energy can accelerate the vulcanization process and improve production efficiency.
Chemical vulcanization:
By adding chemical vulcanizing agents to promote the cross-linking reaction of silica gel, this method is suitable for different vulcanization conditions and application requirements.
Pressure vulcanization:
Apply a certain amount of pressure during the vulcanization process to ensure that the silicone evenly fills the mold and reduces bubbles.
Each vulcanization method has its specific application scenarios and advantages, and the choice of method depends on the requirements of the product, production conditions, and cost-effectiveness. In the production process, it may be necessary to combine multiple vulcanization techniques to achieve the best hardening effect. If you need more specific technical guidance or have specific production issues, please provide more information and I will do my best to assist you.
Precautions for liquid silicone hardening treatment:
1. Raw material selection: Ensure that all raw materials come from reliable suppliers and comply with relevant standards and requirements. Catalysts and crosslinking agents of different brands and models may have different activities and reaction conditions, and should be selected according to specific circumstances.
2. Mixing process: During the mixing process, the vacuum degree and stirring speed should be strictly controlled to avoid introducing bubbles and impurities. Meanwhile, the mixing temperature and time also need to be adjusted according to the characteristics of the raw materials and process requirements.
3. Injection molding: The design of the mold should be reasonable, and the injection speed and pressure should be moderate to ensure that the silicone is evenly distributed inside the mold and eliminate bubbles. In addition, the preheating and cooling of the mold also need to be controlled according to specific circumstances.
4. Hardening conditions: The setting of hardening temperature and time should be determined based on the characteristics of the catalyst and crosslinking agent, as well as the performance requirements of the product. Excessively high or low temperatures, as well as excessively long or short periods of time, can all affect the hardening effect and the physical properties of the product.
5. Post processing: Although the post-processing steps are simple, they are indispensable and directly related to the final quality and appearance of the product. During post-processing, attention should be paid to avoiding mechanical damage or chemical corrosion to the product.
Conclusion:
The hardening treatment of liquid silicone products is a complex and delicate process that involves multiple steps such as raw material selection, mixing technology, injection molding, hardening reaction, and post-treatment. Only by achieving precise operation and strict control at every stage can we produce liquid silicone products with excellent performance and reliable quality.
