Introduction to secondary vulcanization molding of silicone
Feb 25, 2020
In the silicone products industry, many consumers have different levels of product requirements and quality. For example, conventional silicone accessories and other miscellaneous parts can be molded only, and import and export or close to daily necessities. It requires better materials and craftsmanship, so it is far from enough to meet the quality requirements for unilateral materials, which is more important for the post-processing of products.
Production process of silicone products
Under normal circumstances, the products produced by silicone product manufacturers are divided into ordinary silicone, food-grade silicone and medical-grade silicone. The three materials are targeted at three different customer groups and application industries. Ordinary rubber is targeted at industrial, electronic, and peripheral protection. Food. As a silicone product for daily use, some silicone materials that have been in contact with us are basically made of food-grade materials, while medical grades have reached a higher level, and are used as medical product seals, syringes and even surgical auxiliary materials.
Regardless of the grade of material after normal processing of vulcanization, the environmental protection certification for import and export cannot be passed without secondary vulcanization, but it is different after passing the second vulcanization treatment. There is no difference between the second sulfurization and the product after sulfurization, and it can be used normally. The only difference between them is that they will produce compound residues, which will cause odor, yellowing, product toughness decline, and reduced life.
The ordinary molding process is carried out by press molding at a high temperature of about 180 ° C. Different catalytic materials will remain in different rubber materials, so that the corresponding chemical compounds are mixed in the material of the silicone rubber product, which will lead to the failure of testing and certification. Products that need to be tested will choose secondary vulcanization to meet the testing certification standards, and the significance of secondary vulcanization is to vulcanize the sulfur compounds in the product to keep the product free of any hazardous chemicals.
In short, the second sulfurization is equivalent to the silica gel manufacturer's deep disinfection of the newly produced silica gel products. After a high temperature of 220 degrees and 4-8 hours of baking, the compound in the product is subjected to a second volatilization treatment. This produces Silicone products are more safe and environmentally friendly.