The invention and use of ceramics can be traced back to the First World War. British scientist Henry Brearley was commissioned by the British government's military arsenal to study the improvement of weapons. At that time, the barrel of the rifle used by soldiers was very easy to wear, and Blairley wanted to invent an alloy steel that was not easy to wear. The stainless steel invented by Blairley obtained a British patent in 1916 and began Advanced Ceramic Parts mass production. Since then, the stainless steel accidentally found in garbage dumps has become popular all over the world, and Henry Blairley is also known as the "father of stainless steel." During the First World War, British guns on the battlefield were always transported back to the rear because the barrel was worn out and could not be used. The military production department ordered Blairley to develop high-strength wear-resistant alloy steel, specifically researching and solving the wear problem of the barrel. Blairley and his assistants collected various types of steels and alloy steels of different properties produced at home and abroad, conducted performance experiments on machines of various properties, and then selected more suitable steels to make guns. One day, they experimented with a domestic alloy steel containing a large amount of chromium. After wear-resistant experiments, they found that this alloy was not wear-resistant, indicating that it could not make guns. So they recorded the results of the experiment and threw them into the corner. thing. One day a few months later, an assistant rushed to Blairley with a piece of shiny steel and said: "Sir, this is the alloy steel from Mr. Mullah that I found when I was cleaning the warehouse. You Do you want to experiment to Advanced Ceramic Parts see what special effect it has!" "Good!" Breerley said happily, looking at the dazzling steel.

Ceramics are often divided into martensitic steel, ferritic steel, austenitic steel, austenitic-ferritic (duplex) stainless steel and precipitation hardening stainless steel according to their organizational state. In addition, it can be divided into chromium stainless steel, chromium nickel stainless steel and chromium manganese nitrogen stainless steel according to the composition. There is also special Silicon Nitride Ceramic Standard Parts stainless steel "GB24511_2009_Stainless steel plate and steel belt for pressure equipment" for pressure vessels. Alumina ceramics Containing 15% to 30% chromium. Its corrosion resistance, toughness and weldability increase with the increase of chromium content, and its resistance to chloride stress corrosion is better than other types of stainless steels. In this category, there are Crl7, Cr17Mo2Ti, Cr25, Cr25Mo3Ti, Cr28, etc. Because of the high chromium content, ferritic stainless steel has good corrosion resistance and oxidation resistance, but its mechanical properties and process properties are poor. It is mostly used for acid-resistant structures with little stress and as anti-oxidation steel. This type of steel can resist corrosion from the atmosphere, nitric acid and salt solutions, and has the characteristics of good high-temperature oxidation resistance and low thermal expansion coefficient. It is used in Silicon Nitride Ceramic Standard Parts nitric acid and food factory equipment, and can also be used to make parts that work at high temperatures, such as gas turbine parts, etc. . Zirconia Ceramics The chromium content is more than 18%, and it also contains about 8% nickel and a small amount of molybdenum, titanium, nitrogen and other elements. Good comprehensive performance, resistant to corrosion by vari

The zinc content of bronzes in the Shang and Zhou dynasties was very low. There are very few copper-zinc sweet coins in the Western Han and Xinmang coins, some of which contain 7% of zinc, but this does not mean that brass coins were produced in the Western Han Dynasty during the Xinmang period. Because these copper-zinc alloys are very isolated phenomena, their zinc content is generally much smaller than the 15%-40% zinc content of brass in the true sense. Therefore, we Glass Measuring Beaker believe that these zinc-bearing copper coins were produced when the copper-zinc symbiosis mine was used in the "Jishan Zhuqian" in the Han Dynasty. According to the investigation of relevant mines, it was found that there are abundant copper-zinc symbiosis mines in Changwei, Yantai, Linyi, Hubei and other places in Shandong, which makes the copper after smelting contain a small amount of zinc. In the Tang Dynasty, due to the standardization of coin-making materials, the content of zinc in coins made by the coin was always constant. From about 1230 AD, brass products have been popular in Europe for about 300 years because they are much cheaper than large sculptures. The bronze statue of Archbishop Wilp, which began in 1231, is the earliest known bronze statue made of brass. The process of Glass Measuring Beaker casting brass products is as follows: first mix the crushed zinc ore and charcoal with the copper block to heat to combine the zinc and copper, then heat to melt the alloy, and then pour the copper liquid into the casting mold. The earliest brassware in Britain was imported, mainly from Tours. The client can order a complete tombstone from Tourne which has been installed in a beautiful floor or marble base. The way to make a bronze tombstone is to first cast the bronze statue, usually the silhouette of the surrounding canopy, and then place it in a prefabricated stone slab, and use a knife to carve

Silicon Nitride Ceramics Ordinary silicon nitride is a copper-zinc binary alloy, and its zinc content varies widely, so its room temperature structure is also very different. According to the Cu-Zn binary state diagram, there are three types of brass at room temperature: brass with a zinc content of 35% or less, and the microstructure at room temperature is composed of a single-phase α solid solution, called α brass; containing zinc For brass with a content of 36%~46%, the microstructure at room temperature consists of (α+β) two phases, called (α+β) brass (two-phase brass); the Quartz Glass Slid zinc content exceeds 46 %~50% brass, the microstructure at room temperature is only composed of β phase, which is called β brass. Pressure processing performance α single-phase silicon nitride (from H96 to H65) has good plasticity and can withstand hot and cold processing, but α single-phase brass is prone to medium temperature brittleness during hot working such as forging, and its specific temperature range varies with the Zn content Some changes, generally between 200 ~ 700 ℃. Therefore, the temperature during Quartz Glass Slid thermal processing should be higher than 700°C. The reason for the formation of the medium-temperature brittle zone in single-phase α brass is mainly due to the existence of two ordered compounds Cu3Zn and Cu9Zn in the α-phase zone of the Cu-Zn alloy system. The orderly transformation occurs when heated at medium and low temperatures, which makes the alloy brittle; , There are traces of lead and bismuth harmful impurities in the alloy and copper to form a low-melting eutectic film distributed on the grain boundary, causing intergranular fracture during thermal processing. Practice shows that adding a small amount of cerium can effectively eliminate medium temperature brittle

The zinc content of ceramics in the Shang and Zhou dynasties was very low. There are very few copper-zinc sweet coins in the Western Han and Xinmang coins, and some of the coins contain 7% of zinc, but this does not mean that brass coins were produced in the Western Han Dynasty during the Xinmang period. Because these copper-zinc alloys are very isolated phenomena, their zinc content is generally much smaller than the true brass zinc content of 15%-40%. Therefore, Aluminum Nitride Ceramic we believe that these zinc-containing copper coins were produced when the copper-zinc symbiosis mine was used in the "Jishan Zhuqian" in the Han Dynasty. According to an investigation of the relevant mines, it was found that there are abundant copper-zinc symbiosis mines in Changwei, Yantai, Linyi, Hubei and other places in Shandong, which makes the copper after smelting contain a small amount of zinc. In the Tang Dynasty, due to the standardization of coin-making materials, the content of zinc in coins made by the coin was always constant. From about 1230 AD, brass products have been popular in Europe for about 300 years because they are much cheaper than large sculptures. The bronze Aluminum Nitride Ceramic statue of Archbishop Wilp, which began in 1231, is the earliest known bronze statue made of brass. The process of casting brass products is as follows: first mix the crushed zinc ore and charcoal with the copper block to heat to combine the zinc and copper, then heat to melt the alloy, and then pour the copper liquid into the casting mold. The earliest brassware in Britain was imported, mainly from Tours. The client can order a complete tombstone from Tourne which has been installed in a beautiful floor or marble base. The way to make a bronze tombstone is to first cast the bronze statue, usually the silhouette of the surrounding canopy, and then place it in a prefabricated stone slab, and use a knife to

Room temperature tissue Ordinary ceramics are copper-zinc binary alloys, and their zinc content varies widely, so their room temperature structure is also very different. According to the Cu-Zn binary state diagram, there are three types of brass at room temperature: brass with a zinc content of 35% or less, and the microstructure at room temperature is composed of a single-phase α solid solution, called α brass; containing zinc For brass with a content of 36%~46%, the microstructure at room temperature consists of (α+β) two phases, called (α+β) brass (two-phase brass); the zinc content exceeds 46 %~50% brass, the microstructure at room temperature is only composed of β phase, which is called β brass. Pressure processing performance α single-phase ceramics (from H96 to H65) have good plasticity and can withstand hot and cold processing, but α single-phase brass is prone to medium temperature brittleness during hot working such as forging, and its specific temperature range varies with the Zn content The change is generally between 200 and 700°C. Therefore, the temperature during thermal processing should be higher than 700°C. The reason for the formation of the medium-temperature brittle zone in single-phase α brass is mainly due to the existence of two ordered compounds Cu3Zn and Cu9Zn in the α-phase zone of the Cu-Zn alloy system. The orderly transformation occurs when heated at medium Alumina Ceramic Substrate Sheet and low temperatures, which makes the alloy brittle; , There are traces of lead and bismuth harmful impurities in the alloy and copper to form a low-melting eutectic film distributed on the grain boundary, causing intergranular fracture during thermal processing. Practice has shown that adding a small amount of cerium can effectively eliminate medium temperature brittleness.

Advanced ceramic high-density polyethylene resins can be used to mold plastic products by injection, extrusion, blow molding and rotational molding. Various types of containers, industrial accessories, medical supplies, toys, shells, bottle stoppers and protective covers can be molded by injection molding. Various hollow containers and ultra-thin films can be formed by blow molding. Extrusion can be used to form pipes, stretch strips, straps, monofilaments, wire and cable sheaths, etc. In addition, it can also be used to form decorative panels, shutters, synthetic wood, synthetic paper, synthetic film and molded calcium plastic products. Keep away from fire and heat insulation during storage. The warehouse should be kept dry and tidy. It is strictly forbidden to mix in any impurities, sun and rain. Transport should be stored in clean, dry, covered carriages or cabins, and no sharp objects such as iron nails. Mixed transportation with flammable aromatic hydrocarbons, halogenated hydrocarbons and other organic solvents is strictly prohibited. For example, the four-liter barrel of mineral water from Nongfu Spring is this material. Sic Ceramic is the fastest growing part of the plastic material warehouse recycling market. This is mainly due to its easy reprocessing, minimal degradation characteristics and its large number of applications for packaging purposes. The main recycling is to reprocess 25% of recycled materials, such as post-consumer recyclables (PCR), with pure HDPE to make bottles that are not in contact with food. In this process, the polymerization solvent is n-hexane, and the catalyst is a high-activity zN catalyst. After mixing ethylene and hydrogen, it enters the first reactor Sic Ceramic and is mixed with the catalyst to cause polymerization. The polymer in the reactor is suspended in hexane as a slurry. The polymerization temperature i

The ceramic oxide flashed from the second reactor to a pressure of 0.14MPa. The unreacted ethylene, ethane in the effluent and 2% cyclohexane diluent were compressed and cooled to 2.5MPa after two times. The stripping tower recovers the ethane for recycling. The slurry remaining after flash evaporation is centrifuged to recover most of the diluent, and the solid filter cake is sent to the dryer to reduce the volatile content to about 5% (mass fraction). The dryer is operated with nitrogen protection as a closed cycle. The dried polymer powder is sent to a fluidized bed for drying to remove all hydrocarbon diluents. After drying, the polymer particles are sent to the mixing section to add various additives, and then granulated. (2) Loop tube reactor technology The typical Silicon Carbide Ceramics representatives of loop tube reactor technology are Phillips technology of Phillips company and Innovene S technology of INEOS company. The Phillips process uses isobutane as the diluent and uses a chromium catalyst. The catalyst must be activated before use. The activated catalyst powder forms a catalyst slurry with high-purity isobutane under the protection of nitrogen, and then enters the loop reactor After the raw material ethylene monomer is refined, it is premixed with hydrogen and comonomer hexene-1 and then injected into the loop reactor. The ethylene generates polyethylene under the action of the catalyst. The axial flow pump maintains the high-speed flow and very uniform mixing of the materials in the reactor, and the reaction heat is evenly withdrawn by the jacket cooling water. The MI range produced by this process is 0.15-100, and the density is 0.936-0.972 g/cm3. The characteristics of the loop reactor process are: less equipment, short process, low investment cost; no wax and oligomers, no sticking to the wall; good shape of the powder, easy to transport; reaction heat is taken out by the cooling water of the reactor jacket It is

In this century, a revolutionary progress has taken place in the field of pipelines, namely "substituting ceramics for steel". With the rapid progress of polymer material science and technology, the deepening of the development and utilization of plastic pipes, and the continuous improvement of production processes, plastic pipes vividly demonstrate their outstanding performance. Today, plastic pipes are no longer mistaken as "cheap substitutes" for metal pipes. In this revolution, polyethylene pipes have become more and more popular and have increasingly dazzling brilliance. They are widely used in gas transportation, water supply, sewage drainage, agricultural irrigation, mine fine solids transportation, and oil fields, chemicals, post and telecommunications, especially in fields such as It has been widely used in gas transportation. Advanced ceramics is a thermoplastic polyolefin produced by copolymerization of ethylene. Although HDPE was introduced in 1956, this plastic has not yet reached a mature level. This Aluminum Nitride Ceramic general material is constantly developing its new uses and markets. my country`s domestic high-density polyethylene (the high-density polyethylene here does not include the high-density polyethylene produced by the full-density polyethylene device) includes three major companies: PetroChina, Sinopec, and CNOOC. As of the end of 2006, it belongs to the high-density polyethylene of PetroChina. There are 4 sets of polyethylene equipment, namely Lanzhou Petrochemical High Density Polyethylene Equipment, Daqing Petrochemical High Density Polyethylene Equipment, Liaoyang Petrochemical High Density Polyethylene Equipment, Jilin Petrochemical High Density Polyethylene Equipment. High-density polyethylene is usually manufactured by Ziegler-Natta polymerization method, which is characterized by no branches on the molecular ch

Advanced technology industrial ceramics are white powder or granular products. It is non-toxic, tasteless, crystallinity is 80%-90%, softening point is 125-135℃, service temperature can reach 100℃; hardness, tensile strength and creep are better than low-density polyethylene; wear resistance, electricity Good insulation, toughness and cold resistance; good chemical stability, insoluble in any organic solvents at room temperature, resistant to corrosion by acids, alkalis and various salts; the film has low permeability to water vapor and air, and water absorption Low; poor aging resistance, environmental stress cracking resistance is not as good as low-density polyethylene, especially thermal oxidation will reduce its performance, so antioxidants and ultraviolet absorbers must be added to the resin to improve this deficiency. High-density polyethylene film has a lower heat distortion temperature under stress, so pay attention to it when applying it. HDPE has countless applications, ranging from reusable thin-walled beverage cups to 5-gsl cans, which consume 1/5 of domestically produced HDPE. Injection molding grades generally have a melt index of 5 to 10, and there are grades with toughness and lower fluidity and higher fluidity grades with processability. Uses include daily necessities and food thin-walled packaging; tough, durable food and paint cans; high resistance to environmental stress cracking applications, such as small engine fuel tanks and 90-gal garbage Sic Ceramic Moulds cans. The melting point of general ceramics is 142℃, and the decomposition temperature is 300℃; the adjustable range of injection temperature is relatively large. When injection molding, the general use temperature is 180℃-230℃; because it is olefin plastic, it does not absorb water, so it does not need to be dried during production, but for product quality, it can be dried at 60℃ for 1 hour to discha

NO. Polyethylene is very sensitive to environmental stress (chemical and mechanical effects), and its heat aging resistance is worse than the chemical structure and processing of polymers. Polyethylene can be processed by general thermoplastic molding methods. It has a wide range of uses, mainly used to make films, packaging materials, containers, pipes, monofilaments, wires and cables, daily necessities, etc., and can be used as high-frequency insulating materials for TVs and radars. With the development of petrochemical industry, Mechanical Ceramic Parts polyethylene production has developed rapidly, and the output accounts for about 1/4 of the total output of plastics. In 1983, the total production capacity of polyethylene in the world was 24.65 Mt, and the capacity of installations under construction was 3.16 Mt. According to the latest statistics in 2011, the global production capacity reached 96 Mt. The development trend of polyethylene production shows that production and consumption are gradually shifting to Asia, and China is becoming the most important consumer market. Polyethylene is classified into high-density polyethylene (HDPE), low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE) according to the polymerization method, molecular weight, and chain structure. LDPE Properties: tasteless, odorless, non-toxic, matt surface, milky white waxy particles, density about 0.920 g/cm3, melting point 130℃~145℃. Insoluble in water, slightly soluble in hydrocarbons, etc. It can withstand the erosion of most acids and alkalis, has low water absorption, maintains flexibility at low temperatures, and has high electrical insulation. Production process: There are two main types: high pressure tube method and kettle method. In order to reduce t

Properties: As the molecular structures of alumina and zirconia are obviously different, their properties are also different. Compared with LDPE, LLDPE has excellent environmental stress cracking resistance and electrical insulation, higher heat resistance, impact resistance and puncture resistance. Production White Machinable Glass Ceramic Parts 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. Alumina ceramic properties: natural color, 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, 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 temperatures, and has high electrical insulation. Production process: Two production processes, gas phase method and slurry method, are adopted. Uses: use injection molding, blow molding, extrusion, rotational molding and other molding methods to produce film products, daily necessities and industrial use of various sizes of hollow containers, pipes, packa

1. The wall thickness of the product: The wall thickness of the product is related to the flow length of the melt, production efficiency, and use requirements. The ratio of the maximum flow length of ABS melt to the wall thickness of the product is about 190:1. This value will vary depending on the grade. Therefore, the wall thickness of ABS products should not be too thin. For products that require electroplating, the wall The thickness should be slightly thicker to increase the adhesion of the coating to the surface of the product. For this reason, the wall thickness of the product should be chosen between 1.5~4.5mm. When considering the wall thickness of the product, you should also pay attention to the uniformity of the wall thickness. Do not vary too much. The surface of the product that needs to be electroplated should be smooth and free of unevenness, because these parts are easy to adhere to dust and difficult to remove due to static electricity. The fastness of the coating deteriorates. In addition, sharp corners should be avoided to prevent stress concentration. Therefore, it is advisable to use arcs for transitions at corners, thick and thin joints. 2. Demoulding slope: The demoulding slope of the product is directly related to its shrinkage rate. Due to different grades, different product shapes and different molding conditions, the molding shrinkage rate has a certain difference, generally 0.3~0.6%, Sometimes it can reach 0.4~0.8%, so its products have a higher molding dimensional accuracy. The demolding angle of ABS products is considered as follows: the core part is 31° along the demolding direction, and the cavity part is 1°20' along the demolding direction. For products with Bullet Proof Plate Kelvar complex shapes or with letters and patterns, the draft angle should be increased appropriately.

1. Injection temperature: Including the barrel temperature (which can be divided into three sections: back, middle and front), nozzle temperature and mold temperature. Although ABS melt viscosity is less affected by temperature than injection pressure, it is advantageous for thin-walled Silicon Carbide Ceramics molds under high temperature conditions. The decomposition temperature of ABS is theoretically as high as 270t. Above, but in the actual injection molding process, due to the influence of time and other process conditions, the resin often begins to change color at around 2501, and the rubber phase contained in ABS does not adapt to too high temperature, otherwise it will affect the product performance . The molding temperature of ABS requires a slightly higher temperature (at 210-250°C) for resins such as heat-resistance and electroplating grades in order to improve the difficulty of filling the melt or benefit the electroplating performance. For general-purpose, flame-retardant The temperature of ABS resin such as grade and impact grade should be lower to prevent decomposition or unfavorable physical and mechanical properties. The temperature of the plug type injection machine is slightly higher than that of the screw type injection machine. For general products, the temperature range of the plunger type selection is between 180~230℃, while the screw type injection machine is 160~220X: it can be molded . In the molding process, the general barrel temperature (150~1701℃ in the rear, 170~180℃ in the middle, 180~210℃ in the front) The temperature of the nozzle is generally 170~180°C. Special attention should be paid to any changes in the temperature of the homogenization section and the nozzle, which will be reflected on the product, causing flashing, silver wire, discoloration, poor gloss, and obvious weld marks. 2. Mold temperature: Mold temperature has an important effect on

Precision ceramic mechanical properties: density, hardness, surface resistivity, dielectric properties, tensile properties, impact properties, tearing properties, compression properties, bonding strength, wear resistance, low temperature properties, resilience performance; Aging performance: heat aging, ozone aging, Hot Pressed Boron Nitride ultraviolet lamp aging, salt spray aging, xenon lamp aging, carbon arc lamp aging, halogen lamp aging; Liquid resistance: lubricating oil, gasoline, engine oil, acid, alkali, organic solvent, water; Combustion performance: vertical combustion, alcohol burner combustion, roadway propane combustion, smoke density, burning rate, effective combustion heat value, total smoke emission; Applicable performance: hydraulic resistance, impulse test, electrical conductivity, water tightness, air tightness; Production parameters: melt index, viscosity, mold shrinkage, melting temperature, etc. [3] Conventional performance Plastic ABS is non-toxic and tasteless, and its appearance is ivory translucent, or transparent granular or powdery. Density is 1.05~1.18g/cm3, shrinkage rate is 0.4%~0.9%, elastic modulus value is 2Gpa, Poisson's ratio value is 0.394, moisture Hot Pressed Boron Nitride absorption <1%, melting temperature 217~237℃, thermal decomposition temperature>250℃ . Mechanical properties Plastic ABS has excellent mechanical properties, its impact strength is good, and it can be used at extremely low temperatures; plastic ABS has excellent wear resistance, good dimensional stability, and oil resistance, and

Advanced ceramics is an important engineering plastic alloy, which is widely used in automotive, electronic and electrical, office and communication equipment and other fields. Nowadays, in order to meet the special requirements of fire safety in application fields (especially electronic and electrical products), the flame retardant technology of PC/ABS alloy has become a hot spot of research. However, with the advancement of science and technology, the requirements for environmental friendliness of materials are getting higher and higher, and the harm caused by traditional halogen flame retardant is becoming more and more obvious. In engineering, ABS is widely used in engineering pipelines. Generally, ABS pipelines can be used for pool bottom pipelines for projects with relatively high material requirements in municipalities. 3d printing field ABS plastic is one of the main materials for 3D printing. The reason why it can become a consumable for 3D printing is its characteristics. ABS plastic has heat resistance, impact resistance, low temperature resistance, chemical resistance and excellent electrical properties. , Product dimension stability and other characteristics. ABS plastic is the most stable material among 3D printing materials. use The largest application areas of ABS resin are automobiles, electronic appliances and building materials. Applications in the automotive field include automobile dashboards, exterior panels, interior trim panels, steering wheels, sound insulation panels, door locks, bumpers, ventilation ducts and many other components. In terms of electrical appliances, it is widely used in refrigerators, televisions, washing machines, air conditioners, computers, photocopiers and other electronic

Alumina ceramics are used to manufacture everything from tea cups to household insulation materials. The properties of foam plastics (such as density and impact strength) depend on the size and distribution of the cells. These two factors are controlled by the dispersion, percentage and volatility of the added blowing agent. Representative The blowing agents are pentane and isopentane. Flame retardant foamed polystyrene uses halogenated hydrocarbons as flame retardants, which are widely used as sound insulation and heat insulation layers in buildings and engineering applications. The foamable agent SAN has been used to make floating products and other gasoline-resistant products. The following and good grades of low temperature impact resistance. Their Al2o3 Ceramic toughness is very good. The main varieties are: styrene-acrylonitrile copolymer (SAN), styrene-maleic anhydride copolymer (SMA), styrene-butadiene-styrene copolymer (SBS), styrene-acrylate copolymer, And the modified body with them as the base material. The heat distortion temperature of SAN is higher than that of transparent PS, its solvent resistance is also improved, and it has excellent penetration resistance. Rubber-modified SAN includes resins such as acrylonitrile-butadiene-styrene copolymer (ABS) and acrylonitrile-styrene-acrylate copolymer (ASA). The heat distortion temperature of S-MA is higher than that of transparent PS, which can reach 40°F. It has excellent transparency and gloss. SMA can be modified with rubber or reinforced with glass fiber. Various modifications of SBS and SBS can be used as components to improve impact resistance, flexibility and fluidity to produce sticky and anti-bending products such as cement, shoe soles, asphalt felt, etc. SBS is also used to produce transparent impact resistance PS. Styrene can be copolymerized with acrylic elastomer to produce transparent impact-resistant PS with excellent

Advanced ceramics are also called precision ceramics. With the continuous innovation in the field of terminal applications, the main downstream products of polystyrene (PS) are gradually being replaced, and may disappear in the future. This prompted some regional producers to completely withdraw from the business, and the PS industry is gradually being stifled. A resin manufacturer in Taiwan, China believes: "The market lacks new areas that require a large amount of PS, so the demand for PS will gradually decline, and this is not only caused by the global economic crisis." In the production of new game consoles, mobile phones and MP3 players, polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS), and polymethyl methacrylate have been widely used to replace PS. The application of PS is limited to low-end products, such as food packaging, toys, hangers, containers and certain consumer electronic products. However, even in these areas, PS may gradually be replaced by cheaper raw materials such as polypropylene. As an important market for PS, China's demand has been continuously declining since 2003. In 2003, the demand had exceeded 2.6 million tons, and in 2002, it had dropped to 2.3 million tons. Japan's PS market demand has also fallen sharply, especially in the fields of electronics and industrial applications. The production bases of major Japanese PS customers are gradually shifting overseas, which has made it Boron Nitride Ceramic Shaft impossible for Japan's domestic PS demand to recover. Japan's original four PS manufacturers have a combined production capacity of 1.1 million tons per year, accounting for approximately 70% of their domestic market. Japan Polystyrene Corporation, a joint venture between Mitsui Chemicals and Sumitomo Chemical, recently anno

Alumina ceramics temperature is 80~105℃, amorphous density is 1.04~1.06 g/cm3, crystal density is 1.11~1.12 g/cm3, melting temperature is 240℃, resistivity is 1020~1022 ohm·cm. The thermal conductivity is 0.116W/(m·Kelvin) at 30℃. Normal polystyrene is an amorphous random polymer with excellent thermal insulation, insulation and transparency. The long-term use temperature is 0-70°C, but it is brittle and easy to crack at low temperature. In addition there are isotactic and syndiotactic and atactic polystyrene. Identical polymers have high crystallinity, and syndiotactic polymers have partial crystallinity. Polystyrene (PS) includes ordinary polystyrene, expanded polystyrene (EPS), high impact polystyrene (HIPS) and syndiotactic polystyrene (SPS). Ordinary polystyrene resin is non-toxic, odorless, colorless transparent particles, glass-like brittle material, its products have extremely high transparency, light transmittance can reach more than 90%, good electrical insulation performance, easy to color, and process Good fluidity, good rigidity and good chemical resistance. The shortcomings of ordinary polystyrene are brittleness, low impact strength, stress cracking, poor heat resistance and resistance to boiling water. Ordinary polystyrene resin is an amorphous polymer. The side group of polystyrene macromolecular chain is benzene ring, and the random arrangement of bulky side group is benzene ring determines the physical and chemical properties of polystyrene, such as high transparency . Rigidity. High glass transition temperature, brittle and so on. Expandable polystyrene is made by impregnating ordinary polystyrene with a low-boiling physical foaming agent. It is heated and foamed during the processing and is specially used to make foam plastic products. High impact polystyrene is a copolymer of styrene and butadiene, and butadiene is the dispersed phase, which improves the impact strength of the material, but the product is

Silicon nitride ceramics and its aggregated structure determine that it is a hard and brittle material, which exhibits brittle fracture under stress. The characteristic temperature of silicon nitride ceramics is: embrittlement temperature of about -30°C, glass transition temperature of 80 to 105°C, melting temperature of 140 to 180°C, and decomposition temperature of 300°C or more. Since the mechanical properties of polystyrene decrease significantly with the increase of temperature and its heat resistance is poor, the continuous use temperature is about 60℃, and the highest should not exceed 80℃. The thermal conductivity is low, ranging from 0.04 to 0.15W/(m·K), and it is hardly changed by temperature, so it has good thermal insulation. Polystyrene has good electrical properties, with volume resistivity and surface resistivity as high as 1016~1018Ω·cm and 1015~1018Ω, respectively. The dielectric loss tangent value is extremely low, and it is not affected by frequency, environmental temperature, and humidity changes. It is an excellent insulating material. Polystyrene has excellent optical properties, with a light transmittance of 88% to 92% and a refractive index of 1.59 to 1.60. It can transmit visible light of all wavelengths. The transparent material is second only to acrylic polymers such as plexiglass in plastics. . However, because polystyrene has poor weather resistance and is exposed to sunlight and dust during long-term use or storage, turbidity and yellowing will occur. Therefore, when using polystyrene to make high-transparent products such as optical parts, it is necessary to consider adding appropriate varieties and The amount of antioxidant. Good corrosion resistance, poor solvent resistance and oxidation resistance. Silicon nitride ceramics is resistant to various alkalis, salts and aqueous solutions. It is resistant to lower alcohols and certain acids (such as sulf

Ceramic molding is divided into slurry method, solution method and gas phase method. Except for solution method, the polymerization pressure is below 2 MPa. The general steps include catalyst preparation, ethylene polymerization, polymer separation and granulation. ①The polyethylene produced by the slurry method is insoluble in solvents and is in a slurry state. The slurry method has mild polymerization conditions and is easy to operate. Alkyl aluminum is commonly used as activator, hydrogen is used as molecular weight regulator, and tank reactors are mostly used. The polymer slurry from the polymerization tank is passed through the flash tank and the gas-liquid separator to the powder dryer, and then to granulation. The production process also includes steps such as solvent recovery and solvent refining. Different polymerizers can be combined in series or in parallel to obtain products with different molecular weight distributions. ②Solution method The polymerization is carried out in a solvent, but both ethylene and polyethylene are dissolved in the solvent, and the reaction system is a homogeneous solution. The reaction temperature (≥140℃) and pressure (4~5MPa) are relatively high. It is characterized by short polymerization time and high production strength. It can also produce polyethylene with high, medium and low densities, which can better control the properties of the product; but the polymer obtained by the solution method has a low molecular weight, a narrow molecular weight distribution, and solids The content is low. ③Gas-phase method "Ethylene is polymerized in gaseous state, generally a fluidized bed reactor is used. There are two types of catalysts: chromium series and titanium series, which are quantitatively added into the bed from a storage tank, and high-speed ethylene is