And you can see from the outside, one solid and one liquid.
1, liquid silica gel is in the liquid state, with liquidity, it is a high transparent high safety food grade material, molding without adding vulcanizing agent and other auxiliary materials, sealing feeding molding.
2, solid silica gel is a solid state, no liquidity, it is also a transparent environmental protection material, molding needs to add curing agent to speed up the curing time, open mold feeding molding.
Two, liquid silica gel and solid from the use of the difference in the field
1. Liquid silica gel is generally used in baby products, kitchen products and medical products, which can directly contact with food and human body.
2. Solid silica gel is generally used in daily necessities, industrial miscellaneous parts and automobile accessories.
3. Safety of liquid silica gel and solid silica gel: liquid silica gel is a food grade material with high transparency and safety. During molding, no vulcanizing agent and other auxiliary materials are added. Solid silica gel is transparent material, vulcanizing agent is needed to speed up the vulcanizing forming time, open mold feeding molding.
Three, liquid silica gel and solid silica gel molding mode difference
1. Liquid silica gel is injection molding liquid silicone rubber (LSR) : full name is injection molding liquid silicone rubber, vulcanization equipment is injection molding machine.
Injection molding machine has a very simple process (do not need high temperature glue process in the batching, mixing, cutting, laying and other manual processes, only one
High precision (all manual procedures are replaced by machines before molding) and high yield (A/B glue is mixed in
Forming in a few seconds at a certain temperature), saving people, electricity, materials and other advantages, can produce all products produced by high temperature glue.
Liquid silica gel is usually used in industry to make silica sol by removing sodium from water glass by ion exchange method. It is a translucent milky liquid with high stability. The silica sol becomes a porous solid after drying. The specific molding process is as follows:
(1) mixing compound: 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 mixed with pigments and additives to form a rubber mix 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 thermally cured into molded rubber parts.
(4) fluorosilicon rubber blends and base materials: fluorosilicon rubber maintains many key properties of silicone, in addition to superior chemical, fuel and oil resistance.
Synthetic rubber whose backbone consists of alternating silicon and oxygen atoms with organic groups on the silicon atoms. The organic groups in the molecules can be -ch3, -c2h3 or -c6h5, which are called methyl, vinyl or methyl phenyl silicone rubber. Silicone rubber is a kind of special rubber with high and low temperature resistance (-60 ~ 250℃), ozone resistance and good electrical insulation performance.
Organic silicone rubber is a special synthetic elastomer formed by mixing linear polysiloxane with reinforcing filler and curing under heating and pressure. It is a perfect balance of mechanical and chemical properties and can meet the requirements of many demanding applications today.
2, solid silica gel molding is the raw material is a piece of solid, through the mixing machine mixing, cutting machine cut products and mold suitable for large
Small and thickness, after put into the mold, pressure molding machine under a certain temperature molding. Demoulding and plastic products similar, also need to clean the mold.
(1) solid silica gel in industry is made of sodium silicate (sodium silicate) as raw material, hydrolyzed in acidic medium to form gel, and then made into silica gel through aging, washing, drying and other processes. It is translucent or white solid according to the different water content. Commercial products are irregular granular, spherical, microspherical silica gel, commonly used as catalyst carrier in fluidized bed operations.
(2) when used as catalyst carrier, silica gel is usually soaked in the 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 through drying, activation and other procedures. The pore structure of silica gel has important influence on the properties of supported catalyst, such as pore volume and pore size distribution of silica gel. Traditionally, the average pore diameter is less than 15 ~ 20 silica gel, called fine porous silica gel; The average pore diameter is larger than 40 ~ 50, called coarse pore silica gel.
(3) fine pore structure is not conducive to the diffusion of reactant molecules, but can reduce the utilization rate of the catalyst's inner surface, and the product molecules generated at the depths of pores are not easy to escape from the pores, which is easy to cause deep side reactions. The pore structure of silica gel is related to the manufacturing method and conditions, such as gelatinization, aging, pH value, temperature and time of washing, etc. The commercially available silica gel can be expanded through the method of hole expanding, the common method is to put it in the hot pressure kettle add water or add salt aqueous solution (such as sodium carbonate, sodium acetate) hot pressure treatment, for example: in 320℃, 10MPa hot pressure treatment can make the specific surface and average pore diameter of 135m2/g and 123 silica gel into 26.9m2/g and 508.