Those with PP plastic property is what

PP plastic what attributes are those who use PP material Chinese name: English name: Polypropylene Polypropylene is suitable for TV shell, plastic signs, electrical insulation, anti-corrosion pipe, plate, plate, advertising signs, etc. , the specific property and use the following details: the proportion of PP plastic concept: 0. 9 - 0. 91 g/cm3 molding shrinkage rate: 1. 0 - 2. 5% molding temperature: - 160 220 ℃ drying conditions: material performance: the density is small, all strength stiffness, hardness and heat resistance is better than that of low pressure polyethylene, can use at 100 degrees, with good performance and high frequency insulation is not affected by humidity, but low temperature time-varying crisp, not easy ageing, wear-resisting is suitable for making general machinery parts, corrosion parts and insulation parts. Molding performance: 1. Crystalline material, low hygroscopicity, prone to rupture, long-term contact with the hot metal is easy to decompose; 2. Liquidity is good, but the scope and contraction value is big, prone to shrinkage cavity. Dent, deformation; 3. Cooling speed, gating system and cooling system should slow cooling, and pay attention to control the molding temperature, low temperature the direction clear direction, especially when high pressure at low temperature, mold temperature is lower than 50 degrees, the plastic parts is not smooth, easy to cause weld adverse, vestiges of 90 degrees or more prone to buckling deformation; 4. Plastic wall thickness should be uniform, to avoid the lack of glue, sharp corners, to prevent stress concentration. Specific products: easy to decompose under the condition of common basin, barrel, furniture, film, woven bag, bottle caps, plastic plates, bumper, etc. Polypropylene also includes copolymer of propylene and a small amount of ethylene, PP aggregate is ecru, cylindrical particles, particles is bright and clean, the size of the particles in arbitrary direction of 2 mm to 5 mm, odourless non-toxic, no mechanical impurities. This product with high purity acrylamide as the main raw material, ethylene as comonomer, using highly active catalyst in 62 ℃ ~ 80 ℃ and below 4. Under the pressure of 0 mpa bullishness instead should be the production of polypropylene powder, then through drying, mixing, extrusion, granulation, screening, into polypropylene granules. The density of 0. 90 g/cm3～0. 91 g/cm3, which is the lightest of general plastic one. Polypropylene resin with excellent mechanical properties and heat resistance, temperature range - 30℃～140℃。 At the same time has good electrical insulating performance and chemical stability, almost no water absorption, and the vast majority of chemicals will not occur on contact. 30 mpa corrosion resistance, tensile strength, the strength, rigidity and transparency are better than polyethylene; Drawback is the low temperature impact resistance is poor, easy ageing, but can be respectively through modification and adding antioxidants to be overcome. Halogen, benzene, carbon tetrachloride, chloroform, etc of contact corrosion effect. Can be used as engineering plastics, suitable for TV, computer case shell, signs, electric insulation, anti-corrosion pipes, plates, storage tank, etc. , are also used in the production of flat silk, fibers, packaging film, etc. Typical use: the auto industry and consumer goods mainly use PP containing metal additives: fenders, ventilation pipe, fan, etc. , equipment such as: dishwasher, door gasket, drying machine ventilation tubes, washing machine frame and machine cover, the refrigerator door gasket, consumer goods, lawn and garden equipment such as lawnmowers and sprinkler and advertising signs, etc. Injection molding process conditions: dry processing: if stored properly you don't need to dry processing. Melting temperature: 220 ~ 275 ℃, be careful not to exceed 275 ℃. Mold temperature: 40 ~ 80 ℃, it is recommended to use 50 ℃. The crystallization degree mainly determined by the mold temperature. Injection pressure: can be big to 1800 bar. Injection speed: usually, using high-speed injection can reduce internal stress to a minimum. If the products surface defects, the high temperature low injection should be used. Runner and gate: for cold runner, typical flow range is 4 ~ 7 mm diameter. It is recommended to use the brick for round sprue and runner. All types of gate can be used. A typical gate diameter range is 1 to 1. 5 mm, but can also use the little to zero. 7 mm gate. For edge gate, the smallest gate depth should be the half of wall thickness; The smallest width of the gate should be at least twice of the wall thickness. PP material can use hot runner system. All the above content is only for your reference, this article comes from: gains sign factory reprint please indicate the article source.