The following conditions must be taken into consideration when selecting the type and size of the plastic granulator.
(1) According to the specifications of extrusion molding products When plastic extrusion molding products have different specifications, the amount of materials used is also different. Generally choose the extruder specifications when referring to Table 2-1, according to the screw diameter and product specifications reference selection. Then, referring to the basic parameters in Table 1-3, Table 1-3, the screw diameter is selected by the extruder model and the large-size plastic pelletizer is used to produce the smaller-sized product. The power consumption is increased, the wear of the equipment parts is accelerated, and the plastic products are improved. The production cost is an unreasonable choice that does not involve economic calculations and waste.
According to the parameters in Table 1-1 to Table 1-3, if the length-to-diameter ratio of the screw is greater than 25:1, the product specifications of this plastic granulator can be increased accordingly. If extrusion of 0.025-0.15mm thick PE film, the product diameter is 550mm, when the diameter of the screw is 45mm, the screw diameter is 55mm; when the diameter is 1000mm, the screw diameter is 65mm, which can meet the production needs.
(2) Selection according to raw material for extrusion product molding
1) PVC extrusion equipment.
1 single screw plastic granulator. More than 20 years ago, PVC compound extrusion molding more gradual-type single-screw plastic granulator. However, since PVC is a heat-sensitive plastic, the screw speed during extrusion cannot be too high, and the yield is limited. During production, the PVC mixture should be extruded and granulated first, and then the pellets should be extruded. Later, due to the special plastic granulator for PVC powder, the plastic granulator can be used to extrude the mixed PVC powder directly.
For soft polyvinyl chloride products that require plasticizers in PVC materials, they must also be extruded and pelletized before they can be extruded in plastic pelletizers.
2 Tapered counter-rotating twin screw plastic granulator. This type of plastic granulator is suitable in price; it does not cause excessive frictional heat to the extrusion of PVC powder, thus avoiding the decomposition of PVC material due to excessive frictional heat; When the forward movement has nothing to do with the die pressure of the die, the extruding amount is relatively stable. The output of extruded products is relatively small, and the quality performance of products can be guaranteed. At present, when using PVC mixed powder to produce hard PVC products, it should first consider the use of this plastic granulator.
3 parallel opposite twin screw type plastic granulator. With this plastic granulator, PVC powder can be directly extruded into pipes, profiles, and HDPE extrusion pipes. The production of such a plastic granulator is higher than that of the above two plastic granulators, but the plastic granulator is too expensive and more complicated to repair. Therefore, there are few applications at present.
2) Extrusion of other plastics into coral equipment. For extrusion molding of polyethylene, polypropylene, polystyrene, polycarbonate, and ABS plastics, currently, single screw plastic granulators are also used. This is mainly because the plastic granulator is cheap, easy to operate and maintain, and now has an efficient single-screw plastic granulator. This plastic granulator has a screw aspect ratio of 30:1 and a screw speed of 100-300 r/min.
(3) Equipment manufacturer's choice After determining the type and specification of the plastic granulator, how to find the equipment manufacturer is also a problem that should attract attention. To buy domestic equipment, you should find a well-known domestic production plant; if you are ready to import, you should look for an international brand name. These manufacturers have built factories for a long time and have relatively strong capabilities. They have many years of practical experience in producing such products. They have reliable product quality, long service life, and better after-sales service.
If you plan to build a larger plastic product manufacturing plant and plan to purchase more than one plastic machinery and equipment, you can use bidding methods. Pay attention to the comparison of energy consumption, output, and product technical indicators of the same equipment of each manufacturer; equipment price is a major problem, but it should be noted that the product with the lowest selling price is not necessarily desirable; be sure to pay attention to the technical indicators of equipment use period Comprehensive performance comparison. The equipment purchased should be of guaranteed quality, long service life, high grade of supporting parts in the equipment, easy operation and maintenance, long shelf life and high product quality.