The screen changer is a manual or automatic switching device consisting of one or more filters, which is used to filter out foreign particles and impurities when plasticizing material flow filters. As we all know, the cleanliness of the recycled materials and the technological use of the final regenerated particles determine the filtration technical standards of the filtration system. For different melt filtration loads, the conventional non-stop single-plate double-station or two-piston double-station screen-changing filtration system is applied to achieve excellent melt filtration performance.