The structure of the extruder

The structure of the extruder:

1. The feeder is to ensure uniform and stable feeding and adjust the feeding amount according to the rated current value of the extrusion motor. Generally, an electromagnetic speed regulating motor or a frequency converter is used for speed regulation to change the feeding amount of the feeder. The outlet of the feeding hopper is usually fed by a screw auger to the extrusion and puffing section.

2. The expansion cavity is composed of the screw, screw sleeve, template, card bone, etc. The screw and screw sleeve are combined in sections, the degree of compression can be adjusted according to the type and requirements of the extruded feed, and the expansion degree of the extruded feed can be changed.

3. The puffing mechanism is divided into 3 sections in terms of collapse degree according to function and position:

Feeding section: This section has a large screw pitch, which mainly conveys and compresses the material so that the material fills the spiral groove.

Compression section: The screw groove of this section changes from deep to shallow along the material moving direction to compress the material.

Extrusion section: the screw groove is shallower, the pitch gradually becomes smaller, the extrusion force can reach 3.0-10Mpa, and the temperature can reach 120-150 degrees Celsius. This section has the highest pressure and the highest temperature, so the wear of the screw and the screw sleeve is also the most serious.

The outlet of the extrusion section is a template. The shape of the template is designed with different die holes according to the needs of different feeds. The material is extruded from the die hole of the template and enters the atmosphere. The pressure and temperature drop sharply, causing its volume to expand rapidly and moisture Rapid evaporation, dehydration and solidification become extruded materials.