Automotive plastic parts:
PC / ABS polycarbonate and acrylonitrile - butadiene - styrene copolymer and mixture
Typical application: computer and business machine shell, electrical equipment, lawn and garden machinery, auto parts, instrument panels, interior decoration as well as the wheel cover ).
Injection molding technological conditions: dry processing: processing before drying is a must. Humidity should be less than 0.04%, recommend drying conditions for 90~ 110C,2~ 4 hours. Melting temperature:230 ~ 300C. Mold temperature:50 ~ 100C. Injection pressure: depends on the plastic parts. The injection speed: as high as possible.
Chemical and physical properties: PC / ABS with PC and ABS both comprehensive characteristics. For example, ABS easy processing characteristics and PC excellent mechanical properties and thermal stability of. The two PC / ABS ratio will affect the thermal stability of materials. PC / ABS this hybrid material also shows excellent flow characteristics.
PC / PBT polycarbonate and poly butylene terephthalate mixture
Typical applications: gear box, car bumpers as well as with chemical reaction resistance and corrosion resistance, thermal stability, impact resistance and geometric stability of product. Injection molding technological conditions: dry processing: recommendations for 110~ 135C, about 4hour drying treatment. Melting temperature:235 ~ 300C. Mold temperature:37 ~ 93C. Chemical and physical properties: PC / PBT with PC and PBT two combined properties, such as PC high toughness and geometrical stability and PBT chemical stability, thermal stability and lubricating property.
PE-HD high density polyethylene typical applications: refrigerator containers, storage containers, household utensils, seal cover.
Injection molding technological conditions: dry: if stored properly without any drying. Melting temperature:220 ~ 260C. For larger molecules material, suggested melting temperature in the range of 200~ 250C. Mold temperature:50 ~ 95C. The following 6mm wall thickness of the plastic parts should be used with high temperature, more than 6mm thickness of plastic parts used in low temperature. Pieces of plastic cooling temperature shall be uniformly to reduce shrinkage difference. The optimal cycle time, cooling channel diameter shall be not less than 8mm, and away from the mold surface distance should be in 1.3d ( here "d" is the cooling cavity diameter ). Injection pressure:700 ~ 1050bar. The injection speed : recommendations for the use of high speed injection. Runner and gate: runner diameter in the range 4 to 7.5mm, channel length should be as short as possible. Can use various types of gate, the gate length not exceeding 0.75mm. Particularly suitable for use in hot runner mould.
Chemical and physical properties: PE-HD high crystallinity led to its high density, tensile strength, heat distortion temperature, viscosity and chemical stability. PE-HD PE-LD is more than the osmosis resistance. PE-HD impact strength is low. The characteristics of PH-HD mainly by the density and molecular weight distribution control. Applied to the injection mold PE-HD and narrow molecular weight distribution. The density of 0.91~ 0.925g / cm3, we call the first type PE-HD; for the density of 0.926 ~0.94g / cm3, known as the second type PE-HD; for the density of 0.94 ~0.965g / cm3, known as PE-HD third types. The material flow is very good, MFR is 0.1to 28. The high molecular weight, PH-LD flow characteristics worse, but has better impact strength. PE-LD is a crystalline material, shrinkage after molding rate is higher, at 1.5% to 4%. PE-HD is prone to environmental stress cracking phenomenon. Can be achieved by using very low flow characteristics of the material to reduce the internal stress, thereby reducing cracking phenomenon. PE-HD when the temperature is higher than the60C easily in a hydrocarbon solvent, dissolving, but its anti solubility than PE-LD better.
