The main difference between liquid silica gel and solid silica gel is that one is liquid and the other is solid, but after processing the finished product, the two are not so easy to distinguish.
The difference between liquid silica gel and solid silica gel lies in its appearance.
Liquid silica gel is liquid and has fluidity.
Solid silica gel is solid and has no fluidity.
Different areas of use.
(1) liquid silicone is generally used in baby and kitchen supplies as well as medical supplies. It can come into direct contact with food and the human body.
(2) solid silica gel is generally used in daily necessities, industrial miscellaneous parts and auto parts.
(3) the safety of liquid silica gel and solid silica gel: liquid silica gel is a kind of food grade material with high transparency and high safety. auxiliary materials such as vulcanizing agent are not added in the molding process, and the sealing material is formed by sealing.
Solid silica gel is a transparent material.
Vulcanization is needed to accelerate the curing time.
Different forming methods.
Liquid silicone is injection molded liquid silicone rubber (LSR): is injection molded liquid silicone rubber, while vulcanization equipment is injection molding machine.
Injection molding machine process is very simple, high product precision, high output (A / B rubber mixed at a certain temperature for a few seconds), save manpower, electricity, materials and many other advantages, can produce all products of high temperature rubber production.
This product is the mainstream of the development of silicone rubber materials in the next few years.
The raw material of solid silica gel molding is a solid. After stirring by the mixer, the cutter is cut into products and moulds of appropriate size and thickness, and then put into the mold and molded at a certain temperature under the pressure molding machine.
When demoulding is similar to plastic products, the mold also needs to be cleaned.
Different from the finished liquid silica gel, it has high transparency and odorless.
The product has a glue injection port.
The solid silica gel has a transparent bottom and has a vulcanizing agent or other spices covered with a vulcanizing agent.
The product has no injection port.
What is the difference between liquid silica gel and solid silica gel molding?
In industry, solid silica gel is made of water glass (sodium silicate) as raw material, hydrolyzed in acidic medium to form gel, and then made into silica gel by aging, washing, drying, etc., depending on water content, translucent or white solid.
The products sold on the market have irregular granular, spherical and microspherical silica gel, which is usually used as a catalyst for vulcanization in vulcanized bed operation.
When used as a catalyst carrier, silica gel is usually immersed in a solution containing catalytic active components, so that the solution is absorbed into the pores of silica, and the active components are distributed on the surface of silica.
Gelation by drying, activation, etc.
The pore structure of silica gel has an important influence on the properties of the supported catalyst, such as the pore volume and pore size distribution of silica gel.
Generally speaking, the silica gel with an average pore diameter of less than 15 to 20 is called fine pore silica gel, and the average pore diameter of more than 40 to 50 angstroms is called coarse pore silica gel.
The 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 it is possible that the product molecules formed in the pores are not easy to escape from the pores.
Cause profound side effects.
The pore structure of silica gel is related to manufacturing methods and conditions, such as gelation, aging, pH, temperature during washing, time, etc.
The silica gel sold in the market can be reamed by reaming.
The usual method is to heat or add an aqueous solution containing salt (such as sodium carbonate or sodium acetate) in an autoclave, for example, at 320C, the hot pressing treatment of 10MPa can change a specific silica gel.
The surface and average pore sizes are from 135m2 / g and 123to 26.9m2 / g and 508A / g.
Introduction to the process of liquid silica gel.
Liquid silica gel is used in industry to dehydrate sodium water into silica sol by ion exchange.
It is a translucent milky white liquid with high stability.
Solid silica gel becomes porous solid after drying.
For example, in the preparation of (phosphorus-molybdenum-niobium-oxygen) / silica catalyst for the oxidation of propylene to acrylonitrile, the solution containing active components was mixed with silica sol, and the microsphere catalyst was prepared by spray.
Drying; used as food-grade daily necessities, maternal and infant products.