Liquid silica gel and solid silica gel difference
1, liquid silica gel and solid shape
(1) As the name implies, liquid silica gel is a liquid material that is milky white and has good fluidity.
(2) Solid silica gel is a solid material, does not have flow performance!
2, the use of liquid silica gel and solid silica gel
(1) Liquid silica gel is usually used for baby products and kitchen supplies as well as medical supplies. It comes into direct contact with food and the human body.
(2) solid silica gel is generally used for daily necessities, industrial miscellaneous parts (sealing rings, silica gel pads, etc.), automobiles parts, etc., which has a wide range of applications.
3, the safety of solid and liquid silica gel
(1) Liquid silica gel is a food grade material with high transparency and high safety. No auxiliary materials such as vulcanizing agent are added during the molding process, and it is sealed and molded.
(2) Solid silica gel is a transparent and environmentally friendly material. Vulcanizing agent is needed to speed up the vulcanizing molding time.
4, liquid silica gel and solid silica gel formation method
(1) liquid silicone is injection liquid silicone rubber (LSR) : the full name is injection liquid silicone rubber, vulcanization equipment is injection molding machine. Injection molding machine has A very simple process (in high temperature glue process without ingredients, compound, cutting and other manual process, only one of the workers can get products), products of high precision (all before the molding is made by machine instead of manual program), high output (A/B glue with it can be in A few seconds, and under A certain temperature forming, save manpower, save electricity, Save materials and many other advantages, and can produce high temperature glue production of all products! It is the mainstream development of silicone industry in the future. (2) solid silica gel molding is a solid material. After mixing through the mixer, the cutter cuts the product and the mold is suitable. Small and thick, after being put into the mold, the pressure forming machine is formed at a certain temperature. When demoulding is similar to plastic products, the mold also needs to be cleaned.
5, how to distinguish liquid silica gel and solid silica gel products
(1) Liquid silica gel has high transparency, no odor, and the product has a glue injection mouth.
(2) Solid silicon gel has a transparent bottom, vulcanizing agent or other spices covered with vulcanizing agent, the product has no glue injection mouth. Excellent stable heat dissipation performance in the application range of -40℃ to + 150℃.
Liquid silicone
Liquid silica gel forming method
Liquid silica gel in industry is usually made of sodium silicate by ion exchange method to prepare silica sol. It is translucent milky white liquid, has a high stability. Silica sol becomes porous solid after drying. The specific molding process is as follows:
(1) Mixing glue: this ready-to-use material can be colored and catalyzed according to your processing equipment and end use.
(2) Base material: this kind of silicone polymer also contains reinforcing filler. The rubber base can be further blended with pigments and additives to form a compound to meet your color and other manufacturing requirements.
(3) Liquid silicone rubber (LSR) : This two-component liquid rubber system can be pumped into the appropriate injection molding equipment and then heat cured into molded rubber parts.
(4) fluorosilicone rubber mixing rubber and base material: fluorosilicone rubber maintains many key properties of silicone, in addition, it also has superior chemical resistance, fuel and oil resistance.
Synthetic rubber whose main chain consists of alternating silicon oxygen atoms on which organic groups are attached. The organic group in the molecule can be -CH3, -C2H3 or -C6H5, etc., which is called methyl, vinyl or methyl phenyl silicone rubber. Silicone rubber is a kind of special rubber with high and low temperature resistance (-60 ~ 250℃), ozonation resistance and good electrical insulation performance.
Silicone rubber is a special synthetic elastomer which is synthesized by linear polysiloxane mixed with reinforcing filler and vulcanized under heating and pressure. It perfectly balances mechanical and chemical properties and thus meets the requirements of many of today's demanding applications.
Solid silica gel
Solid silica gel forming method
Solid silica gel molding is the raw material is a piece of solid, through mixing machine mixing, cutting machine into the appropriate size and thickness of the product and mold, and then put into the mold, pressure molding machine under a certain temperature molding. Demoulding and plastic products are similar, but also need to clean the mold.
(1) solid silica gel in industry is made of sodium silicate (sodium silicate) as raw material, hydrolyzed into gel in acidic medium, and then made of silica gel through aging, washing, drying and other processes. According to the different water content, it is translucent or white solid. Commercially available products are irregular granular, spherical, microspherical silica gel, commonly used as catalyst carrier in fluidized bed operations.
(2) when used as a catalyst carrier, silica gel is usually impregnated with a solution containing catalytic active components, so that the solution is absorbed in the pores of silica gel, and the active components are distributed on the surface of silica gel after drying, activation and other procedures. The pore structure of silica gel, such as pore volume and pore size distribution, has an important influence on the properties of supported catalysts. Traditionally, the average pore diameter of silica gel is less than 15 ~ 20, called fine pore silica gel; The average pore size is greater than 40 ~ 50, called coarse pore silica gel.
(3) However, the fine pore structure is not conducive to the diffusion of reactant molecules, but it can reduce the utilization rate of the inner surface of the catalyst, and the product molecules generated in the depth of the pore are not easy to escape out of the hole, easy to cause deep side reactions. The pore structure of silica gel is related to manufacturing methods and conditions, such as gelation, aging, washing pH, temperature, time and so on. The commonly used method is to put it in the autopressure kettle with water or salt aqueous solution (such as sodium carbonate and sodium acetate) hot pressing, for example: at 320℃, 10MPa hot pressing can make the specific surface and average pore size of 135m2/g and 123 silica gel into 26.9m2/g and 508.
Source: Silica Gel Encyclopedia website