Introduction of special screw for injection molding machine
Pubdate:2020-03-21 17:44:49
As for the plastics without flame retardant, they can be processed by using general purpose screw, and only need to choose different diameter according to different melting viscosity. If it is a plastic with special function, a special finished product or a plastic with special particle shape, it is necessary to use a special screw. For a certain kind of plastic, the function of general screw is not superior to that of special screw in terms of plasticization and power consumption. The following is a variety of special commodities, special needs and production of special screw for one by one.
PC special screw
PC is a high viscosity non crystalline plastic, with poor fluidity, easy degradation after long-term heating, large feeding torque, difficult melting and easy stagnation. It needs high material temperature and high pressure injection. The material temperature conditioning scale is narrow, and its technicality is inferior to PMMA.
The screw adopts imported high alloy steel full hardening treatment, which can be used to accept high torque, high pressure impact, wear resistance, surface plating, corrosion resistance, smooth without pores to reduce the degradation of surface adhesion. The detailed structure is carefully treated, and the rubber can be avoided, with low shear planning and small heat. Generally, small and medium diameter is adopted, forming pcabs + pcpp-r, flame retardant ABS and other functions are good. It can also form common plastics and PMMA common finished products, but its color mixing effect is poor. For example, adding color powder to plastics, it is necessary to order reinforced color mixing screw.
With the industry's ultra-thin fine molding, the diameter of the supply screw is changed from large to small, from long to short, the injection pressure is improved to more than 3000kgf / cm, and the injection seat is moved forward for transformation (after transformation, it can be normally restored to the original state).
PMMA special screw
PMMA is a high viscosity non crystalline plastic, with strong toughness, high feeding torque, difficult to melt, easy to jam, sensitive to shear and easy to degrade, and slightly poor fluidity. It is necessary to inject with high material temperature and high pressure, with a wide range of material temperature conditioning and good technical performance.
CP, CA acid screw assembly:
With regard to the corrosive properties of acid plastics such as CP and Ca, special planning has been made for the structure and surface treatment of screw, melt cartridge and other plastic parts, which have good corrosion resistance. It is recommended to use double alloy barrel for corrosion resistance.
PVC special screw
PVC plastic can be divided into granular and powdery. It is very sensitive to temperature response and easy to differentiate. It has high viscosity and strong corrosiveness. There are two characteristics of screw planning: chrome plating is necessary on the surface; there is no separating ring and separating meson.
The screw has good plasticization, less shear heating and acid corrosion resistance. Because there is no rubber ring, it can not be used for low viscosity plastics and injection speed pressure grading more accurate finished products.
There are two types of screw planning: integrated screw and dispensing head; separated screw and dispensing head. It is most suitable to use the conjoined type for the high quality request of the commodity and the single plastic (PVC) production only. On the contrary, the split type can be selected. However, it should be noted that the separation of the screw and the rubber head is easy to form the accumulated material. However, we suggest that it is necessary to add a special thermometer for accurate temperature control, because it is necessary to heat and cool down. When making PVC products, the glue cartridge should use forced air cooling measures in combination with the screw. The soft PVC for making toys is outside.
Pu, TPU special screw
Pu cutting is sensitive and easy to over fire, with strong adhesion and special features. It is planned to plating hard chromium on the surface, feeding smoothly, plasticizing power high, temperature rise low soft rubber, EVA foaming special screw low cutting, high transport power planning, and plating hard chromium on the surface.
PET special pole
PET plastic is the common material of plastic bottled drinks at present. It has low viscosity, good fluidity, large specific heat capacity and easy to stick material. The molding temperature is high, but the material temperature conditioning scale is narrow and the technical property is poor. When pet is injected out for molding, if the material temperature is too high, the screw shear is too large or the rotation speed is too fast, it will simply produce acetaldehyde, resulting in acidification.
As for the characteristics of pet and pet preforms that require rapid and even plasticization, the screw has good plasticization, high stability, non stick material, fast melting speed and high rate of bottle preforms blowing. It can also be molded into ordinary plastic. However, it should be noted that the usual producers in the mainland will add water inlet material when making pet bottle blanks. In this case, the special screw for pet is not very suitable. On the contrary, it is usually more suitable for the screw to be chrome plated. It is necessary to add anti salivation equipment to the nozzle.
PA6 / 66 / 46 / 6T special screw
PA is a low viscosity crystalline plastic, with high temperature, fast melting speed, good self-lubricating property, good fluidity, easy to salivate, sensitive temperature, easy to cool head, high moisture absorption, easy to block the screw slot in the feeding section, and difficult to color.
High screw compression ratio, fine check, good color mixing, stable feeding, high plasticizing power, good exhaust effect. Usually take the center diameter, forming PA, pplcp and other crystalline low viscosity plastics with good effect. It can also form ordinary plastics. For PC, PMMA flame retardant ABS and other plastics with high viscosity and poor thermal stability are not suitable (too high temperature and differentiation in the middle section), it is necessary to electroplate hard chromium for forming POM. The constant temperature heating of the nozzle is the best, and it is necessary to add anti salivation equipment.
PPO special screw
PPO is an amorphous material, difficult to melt, easy to jam, sensitive to shear, easy to degrade.
It is recommended to use double alloy to improve wear resistance and corrosion resistance, grade C is enough, screw feeding is smooth and pressure is stable
PBT + GF special screw
PBT is a kind of full resin, semi crystalline material, with high melting degree, rapid solidification, simple differentiation, sensitive to pressure and need to add glass fiber.
It is necessary to use the double alloy to improve the wear resistance. According to the amount of weaving, there are three engineering grades of C, B and a. the pressure of the screw is stable. Molding PBT + gfpa + GF and other crystalline low viscosity engineering plastics usually work well.
PC special screw
PC is a high viscosity non crystalline plastic, with poor fluidity, easy degradation after long-term heating, large feeding torque, difficult melting and easy stagnation. It needs high material temperature and high pressure injection. The material temperature conditioning scale is narrow, and its technicality is inferior to PMMA.
The screw adopts imported high alloy steel full hardening treatment, which can be used to accept high torque, high pressure impact, wear resistance, surface plating, corrosion resistance, smooth without pores to reduce the degradation of surface adhesion. The detailed structure is carefully treated, and the rubber can be avoided, with low shear planning and small heat. Generally, small and medium diameter is adopted, forming pcabs + pcpp-r, flame retardant ABS and other functions are good. It can also form common plastics and PMMA common finished products, but its color mixing effect is poor. For example, adding color powder to plastics, it is necessary to order reinforced color mixing screw.
With the industry's ultra-thin fine molding, the diameter of the supply screw is changed from large to small, from long to short, the injection pressure is improved to more than 3000kgf / cm, and the injection seat is moved forward for transformation (after transformation, it can be normally restored to the original state).
PMMA special screw
PMMA is a high viscosity non crystalline plastic, with strong toughness, high feeding torque, difficult to melt, easy to jam, sensitive to shear and easy to degrade, and slightly poor fluidity. It is necessary to inject with high material temperature and high pressure, with a wide range of material temperature conditioning and good technical performance.
CP, CA acid screw assembly:
With regard to the corrosive properties of acid plastics such as CP and Ca, special planning has been made for the structure and surface treatment of screw, melt cartridge and other plastic parts, which have good corrosion resistance. It is recommended to use double alloy barrel for corrosion resistance.
PVC special screw
PVC plastic can be divided into granular and powdery. It is very sensitive to temperature response and easy to differentiate. It has high viscosity and strong corrosiveness. There are two characteristics of screw planning: chrome plating is necessary on the surface; there is no separating ring and separating meson.
The screw has good plasticization, less shear heating and acid corrosion resistance. Because there is no rubber ring, it can not be used for low viscosity plastics and injection speed pressure grading more accurate finished products.
There are two types of screw planning: integrated screw and dispensing head; separated screw and dispensing head. It is most suitable to use the conjoined type for the high quality request of the commodity and the single plastic (PVC) production only. On the contrary, the split type can be selected. However, it should be noted that the separation of the screw and the rubber head is easy to form the accumulated material. However, we suggest that it is necessary to add a special thermometer for accurate temperature control, because it is necessary to heat and cool down. When making PVC products, the glue cartridge should use forced air cooling measures in combination with the screw. The soft PVC for making toys is outside.
Pu, TPU special screw
Pu cutting is sensitive and easy to over fire, with strong adhesion and special features. It is planned to plating hard chromium on the surface, feeding smoothly, plasticizing power high, temperature rise low soft rubber, EVA foaming special screw low cutting, high transport power planning, and plating hard chromium on the surface.
PET special pole
PET plastic is the common material of plastic bottled drinks at present. It has low viscosity, good fluidity, large specific heat capacity and easy to stick material. The molding temperature is high, but the material temperature conditioning scale is narrow and the technical property is poor. When pet is injected out for molding, if the material temperature is too high, the screw shear is too large or the rotation speed is too fast, it will simply produce acetaldehyde, resulting in acidification.
As for the characteristics of pet and pet preforms that require rapid and even plasticization, the screw has good plasticization, high stability, non stick material, fast melting speed and high rate of bottle preforms blowing. It can also be molded into ordinary plastic. However, it should be noted that the usual producers in the mainland will add water inlet material when making pet bottle blanks. In this case, the special screw for pet is not very suitable. On the contrary, it is usually more suitable for the screw to be chrome plated. It is necessary to add anti salivation equipment to the nozzle.
PA6 / 66 / 46 / 6T special screw
PA is a low viscosity crystalline plastic, with high temperature, fast melting speed, good self-lubricating property, good fluidity, easy to salivate, sensitive temperature, easy to cool head, high moisture absorption, easy to block the screw slot in the feeding section, and difficult to color.
High screw compression ratio, fine check, good color mixing, stable feeding, high plasticizing power, good exhaust effect. Usually take the center diameter, forming PA, pplcp and other crystalline low viscosity plastics with good effect. It can also form ordinary plastics. For PC, PMMA flame retardant ABS and other plastics with high viscosity and poor thermal stability are not suitable (too high temperature and differentiation in the middle section), it is necessary to electroplate hard chromium for forming POM. The constant temperature heating of the nozzle is the best, and it is necessary to add anti salivation equipment.
PPO special screw
PPO is an amorphous material, difficult to melt, easy to jam, sensitive to shear, easy to degrade.
It is recommended to use double alloy to improve wear resistance and corrosion resistance, grade C is enough, screw feeding is smooth and pressure is stable
PBT + GF special screw
PBT is a kind of full resin, semi crystalline material, with high melting degree, rapid solidification, simple differentiation, sensitive to pressure and need to add glass fiber.
It is necessary to use the double alloy to improve the wear resistance. According to the amount of weaving, there are three engineering grades of C, B and a. the pressure of the screw is stable. Molding PBT + gfpa + GF and other crystalline low viscosity engineering plastics usually work well.
Previous:Knowledge of screw barrel renovation of injection molding machine Next:Dongguan screw: what accessories does the injection molding machine have
