hree-stage screw of extruder of melt-blown cloth machine

The role of the feeding section is to send the material supplied by the hopper to the compression section. The plastic generally remains in a solid state during the movement, and is partially melted due to heat. The length of the feeding section varies with the type of plastic, and can be from a short distance from the hopper to 75% of the total length of the screw cup.

In general, extruded crystalline polymers are the longest, followed by hard amorphous polymers, and soft amorphous polymers are the shortest. Since the feeding section does not necessarily need to produce compression, its screw groove volume can be kept constant. The size of the helix angle has a great influence on the delivery capability of this section, which actually affects the productivity of the extruder. Generally, the spiral angle of powder materials is about 30 degrees, the highest productivity. The spiral angle of square materials should be about 15 degrees, and the spherical materials should be about 17 degrees.