Used for granulation and drawing, plate and sheet, blown film, pipe, chemical fiber, adhesive, coating material, wire, cable, material co-mingled granulation, etc. Applicable to all thermoplastics. Single-column double-station screen changer, two detachable filtering stations are designed on the plunger, when working, one filtering station is inside the main body for melt filtration, and the other station is outside the main body for backup. When the impurities on the filter net accumulate to a