Principle of quick extrusion screen changer: The main filter parts of fast extrusion screen changer are composed of slider, positioning pin, feed seal copper ring, gap adjusting nut, shunt plate and discharge seal copper pad, as shown in Figure 1. The main function of the gap-adjusting nut is to adjust by rotation, make the sealing copper ring and one end of the slide plate tightly matched to prevent plastic solution from leaking out between the feed seal copper ring and the slide plate; the pla