The mould head of granulator is a valuable and high-precision part in the granulation production line. In addition to careful operation, it also needs a lot of maintenance. In order to prevent the stoppage caused by die failure, it is necessary to operate correctly and take protective measures to ensure that the die can be used at any time. Carelessness or misoperation in the process of maintenance, cleaning or adjustment is the main cause of die head damage, so it is necessary to carry out strict training for all personnel who contact the die head. The operator must thoroughly understand the function of the die head, know the influence of the temperature change, the adjustment of the die hole or adjusting rod on the product quality, and pay attention to the source of the fault. The operator should also understand the importance of keeping good contact between the heater and the die head, and be able to judge whether there is a fault on the production line and where the fault is?
When there is pulsation in the granulator extrusion, the choke block of the slit die can not be adjusted continuously (generally, the device is not designed for this purpose). He must also be able to judge whether the inlet pressure exceeds the limit according to the measurement results of the inlet pressure. In addition, it should be noted that the die or choke block can not be adjusted quickly, but should be changed moderately in the adjacent area, otherwise the bolt and choke block may be damaged. (Note: only the scraper made of soft materials (copper, brass, soft aluminum) can be used to remove the melt in the die, so as not to scratch the die. The gap width of the die head should also be measured with a soft material such as brass gauge. Even the slightest scratch can lead to streaks on the extrudate and reduce product quality).
When the die head needs to be replaced frequently, especially in the extrusion of film and sheet, it must be operated by a specially assigned person. It is better for someone to have the experience of disassembling, checking and installing the new die head before use. The disassembly, cleaning, repair and maintenance of the die head should be carried out at the designated place, which should be far away from the production site. Pay attention to the cleaning and pad it with corrugated plate. When it is used, it is equipped with a small crane. When it is lifted manually, the iron chain of the pulley block will often damage the die head. In order to avoid this danger, hemp rope can be considered, which can greatly shorten the time of replacing the die head.
Heater inspection is also necessary, the pre heater should be equipped with a certain number of heating wires and control system. At this time, it is not necessary to control each die heater separately, but it depends on the size of the die. If the die head needs to be cleaned thoroughly, the main bolt of the die head must be loosened, but it does not need to be removed. The die head is still connected with the granulator, just loosen the bolt related to the flow channel.