Extruder screw barrel heating and coolingExtruder screw barrel heating and cooling
Extruder screw barrel heating method:
Simple heating is widely used in resistance heating, and thermocouples are used to achieve segmented temperature control and inspection side. Resistance heating is the use of resistance to generate heat to heat the barrel, and then transfer the heat to the plastic in the barrel. Resistance heating mainly includes band heaters, cast aluminum heaters, ceramic heaters, etc. These heaters have the advantages of small size, easy manufacturing and maintenance.
Extruder screw barrel heating power:
When determining the heating power of the barrel, in addition to considering the heat required during plasticization, it also needs to meet the productivity requirements of the injection molding machine to ensure that the barrel has a sufficiently fast heating rate. The heating time of the machine heating does not exceed 30min for small machines, and generally about 1h for large and medium-sized machines.
Cooling of screw barrel of extruder:
① Under normal circumstances, the barrel does not need to be equipped with a cooling control system, and it can meet the process requirements by natural cooling. However, if the temperature of the feed port is too high, the phenomenon of "bridging" will appear at the feed port, making the feeding difficult or even impossible.
② In order to ensure good feeding and solid material transportation conditions and prevent the heat of the barrel from being transferred to the transmission parts, a cooling jacket (slot) should be provided at the feed port of the barrel, and the amount of cooling water can be adjusted according to the process requirements. In addition, when processing heat-sensitive plastics at a higher speed, the machine must be cooled and controlled to prevent the heat-sensitive plastics from being decomposed by heat.