Screw pump is a positive displacement rotor pump, which depends on the volume change of sealing cavity formed by screw and bushing to absorb and discharge liquid. Screw pump is divided into single screw pump, double screw pump, three screw pump and five screw pump. Screw pump is characterized by stable flow, small pressure pulsation, self-priming ability, low noise, high efficiency, long service life and reliable operation; and its outstanding advantages are that it does not form eddy current when conveying medium, is not sensitive to the viscosity of medium, and can transport high viscosity medium.
Each kind of plastic has an ideal plasticizing processing temperature range, and the barrel processing temperature should be controlled to make it close to this temperature range. Granular plastics from the hopper into the barrel, first will arrive at the feeding section, in the feeding section will inevitably appear dry friction, when these plastics are not heated enough, melting uneven, it is easy to make the barrel wall and screw surface wear increased. Similarly, in the compression and homogenization section, if the melting state of the plastic is disorderly and unevenly, the wear will be accelerated.
The speed should be adjusted properly. Because some plastics are reinforced, such as fiberglass, minerals or other fillers. The friction force of these substances on metal materials is often much greater than that of molten plastics. In the injection molding of these plastics, if the high rotational speed is used, the shear force on the plastic will be increased, and the reinforcement will correspondingly produce more torn fibers. The torn fibers contain sharp ends, which greatly increase the wear force. When inorganic minerals slide on the metal surface at high speed, its scraping effect is not small. Therefore, the speed should not be adjusted too high.
Water Ring Vacuum Pump
Dry Scroll Vacuum Pump
industrial vacuum pumps,vacuum furnaces
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