Today, let’s talk about how to change the filter screen of a hollow extrusion blow molding machine.
Let’s take a look at the impact of the hollow extrusion blow molding machine filter on plastic extrusion molding.
In the production process of the plastic blow molding machine, the plastic raw material is transported to the die through the filter. The material can be filtered and the mixing effect of the material can be improved. It is worth noting that the filter screen can also cause fluctuations in the process, causing the backpressure.
and the temperature of the molten material to rise or fall. It is very important to choose the filter. In the design process of the Yankang plastic machine, the filter of the hollow extrusion blow molding machine is fixed on a porous protective plate, which is conducive to the formation of a seal between the plastic blow molding machine and the die. . The pressure generated by the brand-new filter is relatively small. As the working hours increase, more and more impurities will be trapped on the filter, and the pressure will also increase, which will cause the filter to block.
If the filter screen is not replaced for a long time, it will affect the temperature of the molten material. If the pressure drops suddenly, the temperature of the molten material will also drop, which will cause the size of the product to change. In order to ensure the quality of the product, when replacing the blocked filter, it is necessary to adjust the screw speed of the blow molding machine and the linear speed of the blow molding machine.
If you install a gear pump that can ensure that the plastic raw materials enter the mold safely and without error, you can prevent the above problems from happening next to the filter changer. The temperature change of the plastic raw material after the filter is replaced needs to be resolved by adjusting the mold. As the gear pump is easily damaged by hard impurities, the gear pump also needs to be protected by a fine filter.
When extrusion blow molding, do not place the exposed filter on the head of the blow molding machine. Prevent the hydrochloric acid in the air near the machine head from corroding the filter. The best practice when extruding blow-molded products is to install a fume hood above the die to keep the spare filter away from here, or even bag the filter and place it in the freezer. For the extrusion blow molding machine, the backpressure at the filter becomes larger, and the output of the second stage will be reduced, but the output of the first stage will not be affected. When the backpressure increases, the molten material from the first stage begins to leak into the vent. In order to avoid this from happening, be sure to replace the filter when the pressure is low. In addition, the gear pump behind the filter device also has the effect of inhibiting the leakage of molten material into the exhaust hole.
If the filter screen filters a large piece of debris, it will suddenly and completely fail, causing the pressure of the blow molding machine to quickly reach its peak. In order to avoid the above situation, safety systems such as safety diaphragms, safety pins, or alarms connected to the pressure gauge must be installed.
The steel wire filter is easy to rust. When the equipment is not stored, do not contact with water. Once rusted, it will appear in the extrudate. Moreover, the filter screen is prone to breakage after it is rusted, causing the filtered impurities to leak. When storing the filter screen in idle storage, the filter screen must be stored in a plastic bag or rust-proof paper.
Well, the above is the content of how to replace the filter screen of hollow extrusion blow molding machine. Have you learned it?