Solid silica gel processing method, you need to know
Article source: Net editor: Author: popularity: 21 time: 2020-09-26 10:08:00
With the development of silica gel technology, the quality of silica gel products is getting better and better. People tend to choose silica gel products instead of plastic products. Silica gel products are used in more and more fields. It is because of the non-toxic, tasteless and high-temperature resistance characteristics of silica gel that determine its use field. The manufacturing process of different silica gel products is also different. From the form of silica gel, it can be divided into solid silica gel and liquid silica gel products. There are great differences between the two in the production process. So today, Xiaobian takes the most common hot press vulcanization molding process (applicable to all silica gel products) and other processes in solid silica gel processing.
1、 The production process of silica gel solid-state hot press vulcanization mainly includes: raw material preparation - rubber mixing - cutting - hot pressing molding - vulcanization - edge removal - post-treatment - Inspection - packaging.
1. Raw material preparation: the silica gel raw materials purchased are all in blocks, generally milky white. At this time, the raw materials can not be directly hot pressed, but need to add vulcanizing agent (ripening agent). In the process of preparation, ingredients must be weighed accurately according to the formula. In order to make the raw rubber and compounding agent mix evenly, some materials need to be processed (such as color, luminous, fluorescent, conductive, etc., and special requirements such as adding color masterbatch are also required);
2. Rubber mixing: raw materials, vulcanizing agent and other additives required shall be put together according to product requirements. After mixing with rubber mixer, the general mixing time is about 30 minutes (the time is determined according to the weight of rubber mixing raw materials and drum clearance);
3. Cutting material: cut the raw material of silica gel into the size of silica gel. Put the cut raw materials on the awakening rack for a period of time, and the normal raw materials will stand for about 8 hours (both sides of the raw materials are protected by PE mold to ensure the cleanliness of the raw materials);
4. Hot pressing: after the wake-up time. Put the cut rubber in the hot press vulcanizing machine, heat, exhaust, maintain pressure and form;
5. Inspection: conduct product inspection on the formed products to see if there are any bad conditions such as stains, missing edges, immature, cracks, etc., select the defective products (the defective products can only be treated as waste materials), and carry out the next process for the qualified products;
6. Edge removal: rough edge treatment for qualified products;
7. Post treatment: some products need surface spray, printing, radium carving, etc;
8. Inspection: carry out the final inspection on the products and pick out the defective products;
Extrusion molding, extrusion of silica gel products are usually formed by extrusion machine extrusion of silica gel. Generally, the shape of extruded silica gel is long and tubular, which can be cut at will. The shape of products made by extrusion technology is relatively simple, mostly strip-shaped. Silicone tube is widely used in medical and mechanical equipment. It can also be used as a buffer in packaging materials.
Silicone rubber is kneaded and mixed with silica and silicone oil to make rubber compound, and then rolled out into sheet. The physical and mechanical properties of film made by calendering have obvious difference between longitudinal and transverse, which is called calendering effect. The results show that the longitudinal tensile strength of the film is greater than that of the transverse, the transverse elongation at break of the film is greater than that of the longitudinal, and the longitudinal shrinkage of the film is greater than that of the transverse. The calendering effect is the result of orientation of macromolecules, needle like and flake compound along the rolling direction in the calendering process. The size of calendering effect is related to the composition of compound, calendering temperature, speed and speed ratio. For larger products, such as silicone gasket, silicone plate.