How to improve the use of the screw cylinder technology?

2016-12-20

1, each type of plastic, there is a ideal plasticizing processing temperature range, temperature should be controlled cylinder processing, make it close to the temperature range. Granular plastic from the hopper into the cylinder, will first reach the charging period, in period of inevitable dry friction, when the plastic is heated, fused inequality, very easy to cause the inner wall of the cylinder and the screw surface wear. Similarly, in compression and homogenization, if uneven plastic molten state of disorder, can cause increased wear and tear.


2, rotational speed should be proper calibration. As part of the plastic with enhancer, such as glass fiber, minerals, or other filling material. The material of metal friction often is much bigger than the molten plastic. In some plastic injection that if with high speed, is in the increase of plastic shear force at the same time, will also strengthen accordingly produce more fiber is torn, torn fiber containing sharp end, the wear and tear strength increased greatly. Inorganic minerals in the metal surface high-speed taxi, scraping effect is also not small. So the speed shoulds not be too high.


3, to remove impurities in plastic. In general, the original purchase fresh plastic no groceries, but after transportation, weighing, drying, mixed color, add regeneration back material, in particular, it is possible to mix with impurity content. As at the end of the scrap metal, such as fever circle nut paper clips, and even bunchy warehouse keys, entering into the cylinder have occurred, the damage to the screw is self-evident (cylinder, of course, would also damage), accordingly You must install the magnet frame, charge management and strict monitoring.


4, plastic moisture content, the wear on the surface of the screw has a certain influence. If plastic not ruled out all the water before injection molding, the residual moisture into the screw compression section, it forms before melt blended with high temperature and pressure in the molten plastic particles "steam", along with the advancement of injection screw material process, from homogenization section until the screw head, these particles "steam", in the process of shooting material unloading, as each micro hard grain impurity, on the wall surface friction damage. In addition, for some types of plastic, under high temperature and high pressure, the water may become prompted plastic cracking catalyst, can produce the erosion of harmful impurity on the surface of the metal. Plastic injection before baking work, therefore, not only have a direct bearing on the quality of the product, but also affect the life of the screw.


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