Detailed introduction





Use conditions and methods of barrel screw

The method of resistance heating is widely used for simple heating, and thermocouple is used to realize segmented temperature control and side inspection. Resistance heating is to use resistance to generate heat to heat the barrel, and then transfer the heat to the plastic in the barrel. Resistance heating mainly strip heater, cast aluminum heater, ceramic heater and so on. These heaters have the advantages of small size, convenient manufacture and maintenance.
Zhejiang Qijia-Temperature Range of Granulator Barrel
According to material alongScrewIn order to make the degree distribution of the barrel meet the requirements of the injection molding process, the heating of the screw machine must be carried out in sections to improve the plasticizing ability. Generally, (3-5)Ds,(Ds is the rod diameter) is a heating temperature control section, and the heating temperature control fluctuation range should generally not exceed 5 ℃, and it is best not to exceed 2 ℃ for heat-sensitive plastics.
Extruder screw barrel heating power
When determining the heating power of the barrel, in addition to the heat required for plasticization, it is also necessary to meet the productivity requirements of the injection molding machine to ensure that the barrel has a fast enough heating rate. The heating time of the machine is not more than 30min for small machines, but about 1h for large and medium-sized machines.
Cooling of extruder screw barrel
① Under normal circumstances, the barrel does not need to be equipped with a cooling control system, and the process requirements can be met by natural cooling. However, if the temperature of the feed inlet is too high, the phenomenon of "bridging" will appear at the feed inlet, making it difficult to feed, or even unable to feed.
② In order to ensure good feeding and solid material conveying conditions and prevent the heat of the barrel from being transferred to the transmission parts, a cooling jacket (groove) should be set at the feeding port of the barrel, and the 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 temperature controlled to prevent heat-sensitive plastics from thermal decomposition.