The relationship between the production capacity and the screw rotation speed of plastic extruder is that the production capacity increases with the increase of screw rotation speed, but the screw rotation speed of plastic extruder is too high, the production capacity is not improved much, and the glue is easy to be burnt. The relation between the power and the screw speed of plastic extruder is that the power increases with the increase of screw speed, but the speed decreases gradually with the increase of screw speed. The relationship between the head pressure and the number of screw rotation of plastic extruder is that the head pressure increases with the increase of screw rotation speed. Rubber and cylinder: relation between rotating speed and cutting, kneading, plasticizing and heating of rubber in cylinder. Transmission system: the relation between the transmission system and the screw speed of plastic extruder is that the lower the screw speed, the larger the reduction ratio of the transmission system, making the structure of the transmission system complex.

The inner surface hardness of plastic extruder barrel is higher than that of plastic extruder screw. The scrap of plastic extruder barrel is the increase of inner diameter due to time wear. If there is a certain nitrided layer in the cylinder of the plastic extruder, the inner bore of the cylinder can be bored directly to a new diameter size, and then the screw rod of the new extruder can be prepared according to this diameter.

The inner diameter of the cylinder of the plastic extruder is machined, repaired and re-cast the alloy, with thickness of 1~2mm, then refined to the size. Generally, the uniform section of the plastic extruder cylinder wears faster, and this section (5~7D long) can be dressed through boring holes and equipped with a nitriding alloy steel bushing. The diameter of the inner bore of the plastic extruder cylinder refers to the diameter of the screw rod of the extruder.