Extruder filter Screen Maintenance Items

With the development of the plastics industry, plastic extruders have become popular in the plastics production industry. Learning how to maintain and how to maintain the plastic extruder is very helpful to our production. Today we are talking about the filter in the extruder, which aspects should be noted in the actual production.

1: Since ordinary wire mesh screens are prone to rust, avoid moisture during storage, otherwise rust will appear in the extrudate. What's more, rusted filters are prone to breakage and allow filtered impurities to leak through, so the filters are stored in plastic bags or rust-proof paper, but now there are alternatives to wire mesh — - Stainless steel filter. (BangMai Metal Mesh Factory specializes in producing various models of stainless steel strainers.)

2: When the PVC material is being extruded, the bare filter must not be placed on the extruder head. This is because the hydrochloric acid in the air near the head mold will corrode it. The best practice when extruding PVC is to install a fume hood above the die, and be sure to keep the backup filter away from it, or even pack it in a freezer.

3: When the purge and cleaning of the protection board is very easy to appear rewinding phenomenon, so that the sealing surface is damaged, and the sliding surface does not match, resulting in leakage. This will not only result in time-consuming cleaning, but also leaks of molten material that can affect the thermocouple value, as well as damage the heater, and may even cause a fire.

4: For a single-exhaust, two-stage extruder, if the back pressure at the filter becomes larger, then the second stage of production will be reduced, but the output of the first stage will not be affected. When the back pressure increased to approximately 2500 lb/in2 (1 lb = 45536 Kg, 1 in = 25.4 mm), the molten material from the first stage began to leak into the vent. In order to avoid this, it is important to replace the filter when the pressure is low. In addition, the gear pump behind the filter device also inhibits the leakage of molten material into the vent.

5: If the filters filter to large debris (such as paper), it will suddenly fail completely, which will make the extruder pressure quickly peak. Therefore, in order to prevent this from happening, there must be a safety system such as a safety diaphragm, a safety pin, or an alarm connected to a pressure gauge.

Summary: If the extruder filter does the above 5 points, then basically you can do not worry about filters.