Three structural forms of common screw of extruder

Screw is the core component of extruder. Not only is it essential, but it is especially important. What I want to introduce to you today is the three structural forms of the common screw in the extruder: according to the change of the thread lift and the depth of the screw groove, the conventional full-thread three-segment screw can be divided into three forms :(1) Equidistant deep-changing screw the speed of the Auger depth change of the equidistant deep-changing screw can be divided into two forms: ① equidistant gradual-changing screw: the depth of the last screw groove from the feeding section to the homogenization section is a gradually shallower screw. On the longer melting section, the depth of the screw groove gradually becomes shallow. (2) isometric mutant screw: that is, the screw groove depth of the feeding section and homogenization section remains unchanged, and the screw groove depth at the melting section suddenly becomes shallow (2) Equal depth change distance from screw equal depth change distance from screw means that the depth of screw groove is constant, and the pitch starts from the first screw groove in the feeding section to the end of the homogenizing section is gradually narrowed from the width. The characteristic of the screw with equal depth change is that the screw groove is so deep that the cross-sectional area of the screw at the feeding port is large and has sufficient strength, which is conducive to increasing the rotating speed and thus improving the productivity. However, the screw processing is more difficult, the melt flow rate is larger, the homogenization effect is poor, and it is less used (3) Deepening and pitch-changing screw deepening and pitch-changing screw means that the depth of the screw groove and the lifting angle of the screw thread change gradually from the beginning of the feeding section to the end of the homogenization, that is, the screw thread lift gradually narrows from the width, screw whose depth of screw groove gradually changes from deep to shallow. The screw has the characteristics of the first two kinds of screws, but the machining is more difficult and less used.