PMMA PMMA lampshade Large extrusion plates are required to be imported from abroad. The consumption of Chinese PMMA acrylic (acrylic) has increased rapidly. However, due to the monotonous varieties, less quantity and poor quality of China's plexiglass PMMA products, it is far from meeting the needs of the domestic market, resulting in a significant increase in import volume every year. In 2000, the import of PMMA moulded plastics in China reached 77 thousand tons, and at the same time, nearly 4000 tons of organic glass plates were imported. From the point of view of import, the total imports of 4 provinces and cities in Guangdong, Shanghai, Zhejiang and Jiangsu accounted for about 95% of the total import of the country. In 1980s, the annual sales volume of acrylic (acrylic) organic glass in China was less than 20 thousand tons, and the consumer market was not dominated by the construction industry. Since entering 90s, the market application of PMMA in construction industry has developed greatly. Consumption has increased rapidly. In 2000, it has reached 85 thousand tons, including 29 thousand tons of pouring boards, 25 thousand tons of extruded plates, and 31 thousand tons of moulded plastics (excluding Extrusion Moulds). It is expected that in the next few years, the growth rate of the Chinese acrylic plexiglass market will remain above 6% annually. The market capacity of acrylic plexiglass in China is estimated to be 110 thousand tons by 2005, of which construction industry accounts for about 60% to 70%. In the early 20s, Solomon ha new company first invented by MMA polymerization of acrylic board (acrylic board) method, this plate is called "oroglas/plexiglas". However, the company failed to find a more economical process for producing MMA, so the acrylic board (acrylic plate) was not popularized at the time. In 1931, ICI scientists invented the acetone cyanohydrin method for the production of MMA, this method greatly reduces the cost of MMA, the PMMA (acrylic board) has been popularized. At the same time, ICI also successfully developed acrylic plate (acrylic board) for aircraft cockpit top cover and other fields. Subsequently, ICI built the world's largest acrylic plate plant in the UK. Acrylic plate and organic glass The organic glass comes from the commodity name "oroglas", meaning "organic glass". As mentioned earlier, oroglas is actually one & amp PMMA plate, that is, acrylic plate. Some people in China think that transparent plastic is plexiglass. In order to avoid confusion and misunderstanding, most of the PMMA The material of the fully transparent chassis and the multicolor chassis. No matter the colourful chassis and the fully transparent chassis, the materials are all organic glass plates, that is, acrylic plates. There are all transparent organic glass panels, blue organic glass board, yellow organic plate and so on. TPU(1) the weight of finished product, must be below 70% in the feed pipe forming capacity, such as the need for a level beyond the machine, so the material of high hardness, high viscosity, hydraulic motors usually need to increase the level of the driving torque. (2) the resistance of raw material to flow in the pipe is small and the loss of pressure is less. The feeding tube group 0. 03-0. 04mm plating, increase hardness and smooth small resistance force |. (3) its fluidity is not as good as that of ABS. It must be shaped by increasing injection pressure and velocity, and prone to sag and internal bubbles. (4) melt speed may slow down about 40%-50%, to increase the heat of fusion, between the melt with 70~90kg/cm2 gauge more appropriate, which can adjust the temperature of material. (5) when the shrinkage?or?vacuum bubble occurs, other conditions can not be solved, adding back pressure can be solved between 5kg/cm2~20kg/cm2. If the back pressure is too high, it will cause overheating and difficult driving. (6) if it stays in a heated material tube for too long, it will cause too much gas. Sometimes it will not drive easily because of the resistance of gas. It can use continuous injection and loosening to eliminate gas. (7) if not finished flesh to shorten the cooling deformation, can be slowly cooling by soaking in warm water, and skin temperature difference is not too large, so can shrink vacuum bubble. (8) when the finished product has residual stress, the strength of the finished product will be reduced when it is exposed to the solvent. In order to eliminate the internal stress, hot mold production can be used, and the injection pressure can be reduced if the material temperature is increased. If the compression is used, the internal stress hardly exists. (9) if the finished product has been produced many times, in order not to be scrapped due to too high internal stress, annealing treatment can be carried out, which can relieve the tension of the outer surface and relieve the internal stress. (10) second material recovery, in order to clean the best material for the pipe, set about 240 C. (11) as in the low temperature after molding, material tube temperature a little higher than the screw does not produce sharp sound. Processing technology POM Dielectric loss angle tangent value (10Hz) Zero Point Zero Zero Five Zero point zero zero seven - Dielectric strength (kV/mm) Twenty Twenty - Resistance to arc, s 220240 -PPA When the melting temperature of injection is in the range of 615 - 650 F, the retention time of the material in the barrel is not more than 10 minutes, so the mechanical properties of the injection products are the best. The mold temperature is required at least 275 F in order to get the best product with perfect crystallization and dimensional stability. A part with a thick wall can be injected at a lower mold temperature because of the slow cooling rate. The mold temperature is crucial to the optimization of the surface sensitivity of the finished parts. The surface temperature of the mold surface for the mineral filler grade PPA resin for the vacuum plating metal plating metal requires 350 F. Because of the outstanding physical, thermal and electrical properties of PPA resin, especially the moderate cost, it has a wide range of applications. These properties, together with excellent chemical resistance, make PPA a candidate for many uses in the automotive industry. The trend of better aerodynamic design and higher performance motor will improve the temperature of the engine box, making the traditional thermoplastics not applicable. These new requirements make PPA one of the candidate materials for making the following components: automobile headlight reflector, bearing seat, pulley, sensor shell, fuel pipeline components and electrical components. Medium plastic online plastic Encyclopedia The development direction of electrical components is miniaturization and high temperature unity, such as infrared consolidation and steam phase unity, which requires superior performance of PPA. The flame retardant PPA has excellent electrical properties, high HDT value, high temperature bending modulus and thin wall parts that can grow with the smallest overflow. Therefore, it is suitable for making switchgear. The connector, the brush seat and the motor bracket. Mineral filler grade PPA is used for reflective surface and metal plating, including automotive headlights, decorative fittings and hardware. The unreinforced impact modified PPA has excellent mechanical and high temperature properties. Supernormal toughness and these properties are extremely affected by humidity. Their uses include oilfield components, military products, sporting goods, fan impeller and gears, and personal safety products. Medium plastic online plastic Encyclopedia High gloss and good abrasion resistance Low density Good adhesion with Grilamid 1S PA1010 Grivory HT3 PPA (polyphthalamide) Main features: High biological content Compared with other PPA, the hygroscopicity is very low Higher dimensional stability Excellent chemical resistance and water resistance Higher peak temperature resistance and heat resistance Suitable for lead-free welding Halogen free flame retardants in electrical and electronic applications According to the different polymer types, the biological content of GreenLine products ranges from 50% to 99%. This data is determined according to ASTM D 6866-12 and expressed as percentage of total carbon.