The properties of alumina ceramics: As the molecular structures of LLDPE and LDPE are significantly different, their properties are also different. Compared with LDPE, LLDPE has excellent environmental stress cracking resistance and electrical insulation, higher heat resistance, impact Thermal Expansion Ceramic Substrate Elctronic Components resistance and puncture resistance. Production process: LLDPE resin is mainly produced by full-density polyethylene equipment. The representative production processes are Innovene process and UCC's Unipol process. Uses: Production of films, daily necessities, pipes, wires and cables through injection molding, extrusion, blow molding and other molding methods. Properties: Natural, cylindrical or oblate particles, the particles are smooth and clean, the size of the particles should be 2 mm to 5 mm in any direction, without mechanical impurities, and with thermoplasticity. The powder is white powder, and the qualified product is allowed to have a slight yellow color. It is insoluble in general solvents at room temperature, but it can swell when exposed to aliphatic hydrocarbons, Thermal Expansion Ceramic Substrate Elctronic Components aromatic hydrocarbons and halogenated hydrocarbons for a long time, and it is slightly soluble in toluene and acetic acid above 70°C. Oxidation occurs when heated in the air and under the influence of sunlight. It can withstand most acids and alkalis. The water absorption is small, it can still maintain flexibility at low temperature, and has high electrical insulation. Production process: Two production processes, gas phase method and slurry method, are adopted.
Uses: using injection molding, blow molding, extrusion molding, rotational molding and other molding methods to produce film products, daily necessities and Thermal Expansion Ceramic Substrate Elctronic Components industrial use of various sizes of hollow containers, pipes, packaging calender belts and ties, ropes, fishing nets and weaving Fiber, wire and cable, etc. Polyethylene resin is a non-toxic, tasteless white powder or granule, with a milky white appearance, a wax-like hand, and low water absorption, less than 0.01%. The polyethylene film is transparent and decreases with the increase of crystallinity. Polyethylene film has low water permeability but high air permeability, which is not suitable for fresh-keeping packaging but suitable for moisture-proof packaging. It is flammable and has an oxygen index of 17.4. It has low smoke during combustion, with a small amount of molten droplets, yellow on the flame and blue underneath, with a paraffin odor. Polyethylene has better water resistance. The surface of the product is non-polar, which is difficult to bond and print, and it is improved by surface treatment. Many branches have poor resistance to light degradation and oxidation. Its molecular weight is in the range of 10,000 to 100,000. Those with a molecular weight of more than 100,000 are ultra-high molecular weight polyethylene. The higher the molecular weight, the better the physical and mechanical properties and the closer to the required level of engineering materials. But the higher the molecular weight, the more difficult its processing. The melting point of polyethylene is 100~130℃, and it has excellent low temperature resistance. It can still maintain good mechanical properties at -60℃, but the use temperature is 80~110℃.
It is insoluble in any known solvents at room temperature, and can be dissolved in a small amount in toluene, amyl acetate, trichloroethylene and other solvents above 70°C. Polyethylene has good chemical stability and can withstand dilute nitric acid, dilute sulfuric acid and any concentration of hydrochloric acid, hydrofluoric acid, phosphoric acid, formic acid, acetic acid, ammonia, amines, hydrogen peroxide, sodium hydroxide, potassium hydroxide, etc. at room temperature Solution. But it is not resistant to strong Thermal Expansion Ceramic Substrate Elctronic Components oxidative corrosion, such as fuming sulfuric acid, concentrated nitric acid, and a mixture of chromic acid and sulfuric acid. The above-mentioned solvents will slowly corrode polyethylene at room temperature, while at 90-100°C, concentrated sulfuric acid and concentrated nitric acid will quickly corrode polyethylene, causing it to be destroyed or decomposed. Polyethylene is prone to photo-oxidation, thermal oxidation, and ozone decomposition, and is prone to degradation under the action of ultraviolet rays. Carbon black has an excellent light shielding effect on polyethylene. After being irradiated, cross-linking, chain scission, and formation of unsaturated groups can occur.
What are the properties and applications of alumina ceramic?
2020 11/02