The characteristics of security and the main purpo...

Silica gel is a highly active adsorption material is amorphous material, its chemical formula mSiO2 · nH2O was. Insoluble in water and any solvent, non-toxic, tasteless, chemically stable, in addition to alkali, hydrofluoric acid does not react with any substance. Various types of silica manufacturing methods and the formation of different porous structure. The chemical composition and physical structure of the silica gel, it difficult to replace a number of other similar materials have characteristics: high adsorption properties, thermal stability, chemical stability, high mechanical strength. Silica gel according to the size of its aperture is divided into: macroporous silica gel, wide pore silica gel, B-type silica gel pores of silica gel. Due to the different pore structure, and therefore their adsorption properties have their own characteristics. Coarse silica gel under high relative humidity, high adsorption capacity, pore silica gel adsorption capacity in the case of low relative humidity above the coarse silica gel, B type silica gel between the coarse pore structure, pore silicone between the adsorption capacity between coarse pores between. Macroporous silica gel is generally used as a catalyst carrier, matting agent and toothpaste abrasive. Should therefore be selected according to different purposes of different varieties. Silica gel adsorption of water exposure, burning roasted, dried, and methods such as regeneration. Safety performance Silicone main component is silicon dioxide, chemically stable, non-toxic. Silica gel has a strong adsorption capacity, can produce dry human skin. If the silicone into the eyes need to use plenty of water and seek medical treatment. Blue silicone because it contains a small amount of cobalt chloride, toxic, and should be avoided and food contact and inhalation of the mouth, such as the occurrence of poisoning should immediately seek medical treatment. The main purpose Characteristics of silica gel adsorption strength quickly and effectively absorb moisture within the sealed package, chemically stable, non-toxic harmless; combined in recent years, continuous innovation and development, all kinds of silicone has been used in drug purification, DNA separation, food dry, high-precision electronics, cosmetics, waste water purification, purification of beer, and advanced coatings and resin production or preservation of other aspects. In our daily life and production and business activities, silica is often used in the following areas: Precision optical instruments, electrical and electronic dry mold packaging; Drying of leather, such as leather, leather bags, shoes play a role in the drying shelf life; Food drying, more common in order to ensure food crunchy biscuits and fried foods; Drug drying, put in vials, to ensure that the drugs to extend the shelf life; Dry container: the transport of containers at different latitudes will form the box "within the rain, if you are using a silica gel desiccant, it can absorb the equivalent of its own weight of water, ocean shipping up to 50 days, you can effectively reduces the dew point of leaving the container of the condensate phenomenon under control. Hotel to use the class of goods, such as placed in the closet, shoes, and under the bed, the adsorption of a variety of odor, keep the air dry and fresh. Beer silica gel Properties: Beer silica gel is an amorphous microporous structure of the solid powder, the pore size of 8-16nm, the chemical formula for mSiO2 · nH2O was insoluble in water and any solvent except the caustic alkali and hydrofluoric acid, not with any acid alkali, salt from the reaction, non-toxic, tasteless, no burning, no explosion, with a strong heat, cold stability, not harmful to humans. Mainly used in the beer industry. Functions: Beer silica gel with a large surface area and numerous suitable porous structure may cause beer turbid protein adsorption in a few minutes, removed by filtration, thus prolonging beer storage period of 180-240 days, to prevent beer from being cold muddy. (2) does not affect the beer foam and flavor. The physicochemical properties of beer silica gel its beer foam and flavor has no effect on the practice that beer silica gel is recognized by the world beer industry the safest beer stabilizer. (3) to improve the effect of filter aids. Beer silica gel chemically stable, excluding beer solubles, its surface area and porous structure are much better than the diatomaceous earth, good drainage aids, auxiliary diatomaceous earth filter, making beer brighter and more clear. Blue silicone Properties: Blue silicone into the blue gel indicator, silica gel blue gel, the appearance of blue or light blue glass-like particles, the particle shape can be divided into two kinds of spherical and massive, with the role of the silica gel adsorption moisture, and can with increasing moisture content, its own color from blue became purple, and finally become light red, not only indicates the humidity of the environment, but also visualize whether there is still a moisture-proof effect. Purposes: (1) is mainly used for equipment, instruments, equipment, etc. to absorb moisture in confined conditions, anti-rust. 2 used in conjunction with ordinary silica gel desiccant, indicating desiccant to absorb moisture and judgment of the relative humidity of the environment. Packed with silica gel desiccant, widely used in precision instruments, leather, clothing, food, medicines and household appliances. Silica sol Properties: The silica sol is a colloidal solution, odorless, non-toxic formula can be expressed as mSiO2nH2O. Fine colloidal particles (10 - 20nm), there is a large specific surface area, particle itself is colorless and transparent, and does not affect the true qualities of the materials to be covered. Low viscosity, can penetrate where water can penetrate the dispersion and permeability are very good when mixed with other substances. Water evaporation when the silica sol, the colloidal particles firmly attached to the surface, the particles form a silicon-oxygen combination is a good adhesive. Purposes: One used for a variety of refractory binder, with a strong adhesive, high temperature (1500-1600 ° C), and so on. (2) for the coatings industry, make the paint solid, but also stain-resistant dustproof, anti-aging, fire and other functions. Used in precision casting of thin, increase the cover strength, finish casting. Its shape better than the quality of water glass shape, instead of the TEOS modeling to reduce costs and improve operating conditions. (4) silica sol have higher specific surface area can be used for the manufacture of catalyst and catalyst support. (5) for the paper industry, can be used as the cellophane anti-adhesive, pre-treatment agent in the photographic paper, cement bags non-slip agent. 6. Used as a sizing agent of the textile industry, and oil and processing wool, rabbit hair spinnability, reduce breakage and prevent fly, increase yield, increase economic efficiency. 7 as a silicon steel processing agent, CRT dispersant, floor wax sliding Rubber High elastic polymer. Rubber word comes from the Indian cau-uchu, which means "weeping tree". Natural rubber latex by the outflow from Hevea tapping solidification, after drying the system (see figure). In 1770, the British chemist J. Priestley discovered that rubber can be used to wipe the pencil writing, such use of the material known as rubber, this term still in use. The molecular chain of rubber can be crosslinked, crosslinked rubber by the external force deformation, and the ability to recover quickly and have good physical and mechanical properties and chemical stability. The rubber is the rubber industry's basic raw material, widely used in the manufacture of tires, hoses, tape, cable, and a variety of other rubber products. Types of rubber raw materials into the natural rubber and synthetic rubber. According to the shape is divided into a block of raw rubber, latex, liquid rubber and powdered rubber. The water dispersion of colloidal latex for rubber body; oligomer liquid rubber rubber, unvulcanized, is generally a viscous liquid; powdered rubber latex processed into powder, ingredients and processing production in order to benefit. Development of thermoplastic rubber in the 1960s, no chemical curing, molding and thermoplastic processing methods. Rubber general-purpose and special use is divided into two categories. The better performance of general-purpose rubber, widely used. Mainly: (1) natural rubber. Get from Hevea latex system, the basic chemical composition of the cis - polyisoprene. Good elasticity, high strength, good overall performance. ② isoprene rubber. The full name of the cis 1,4 - polyisoprene rubber, synthetic rubber, high-cis-isoprene system, because of their structure and properties of natural rubber approximation, it is also known as synthetic natural rubber. ③ styrene butadiene rubber. Referred to as SBR, butadiene and styrene system have. Production methods into the emulsion polymerization of styrene butadiene rubber and solution polymerization styrene-butadiene rubber. Its properties and chemical stability. (4) cis-1 ,4-polybutadiene rubber. The full name of the cis-1, 4 - polybutadiene rubber, referred to as BR, by the polymerization of butadiene obtained. And other general-purpose rubber, in particular, excellent cold resistance, abrasion resistance and elasticity of vulcanized butadiene rubber under dynamic load is less heat resistance, good aging properties and natural rubber, chloroprene rubber, nitrile rubber, etc. and . The special rubber refers to some special properties of rubber. : (1) neoprene. Referred to as the CR, chloroprene polymerization system. Good overall performance, oil and flame resistant to oxidation and ozone resistance. But its density is large, easy to crystallize at room temperature hardened storage is bad, poor resistance to cold. ② nitrile rubber. Referred to as NBR, butadiene and acrylonitrile copolymer system have. Oil resistance, good aging properties, in 120 ° C in air or at 150 ° C oil and long-term use. In addition, water resistance, air tightness and excellent bonding properties. ③ silicone rubber. Main chain composed of alternating silicon and oxygen atoms with organic groups on silicon atoms. High temperature resistance, ozone resistance, good electrical insulating properties. ④ fluorine rubber. The molecular structure containing fluorine atoms in synthetic rubber. Usually the number of fluorine atoms, fluorinated units in the copolymer, such as fluorine rubber is a copolymer of vinylidene fluoride and chlorotrifluoroethylene. Viton high temperature resistance, oil resistance, chemical corrosion. The ⑤ thiokol. By the two alkyl halides with alkali metal or alkaline earth metal polysulfide condensation. Excellent oil resistance and solvent resistance, but the intensity is not high, resistance to aging, poor workability, smell, and more with nitrile rubber. In addition, polyurethane rubber, epichlorohydrin rubber, acrylic rubber and so on. The basic process of the rubber processing including mastication, mixing, rolling or extrusion, molding and curing the basic process, each process for the products have different requirements, respectively, with a number of auxiliary operations. To be able to with all the necessary agent in the rubber, raw rubber first need to improve its plasticity after mastication; by mixing carbon black and rubber chemicals and rubber mixed synthetic rubber material; rubber after pressure a made of a certain shape of the billet; combination of it with glue or adhesive of rolling-hanging textile materials (metal materials) together forming a semi-finished plastic semi-finished products made of high elasticity of the final product; after vulcanization turn has .