Screw extruder depends on the pressure and shear force produced by screw rotation, which can make the material fully plasticized and evenly mixed, and can be molded by die.
The shell of the head is usually bolted on top of the fuselage. The mold inside the head contains a mold core seat, and then the nut is fixed to the inlet port of the head, and the inner part of the die core seat is also provided with a mold core.
In addition, the core and the center of the core seat have holes, which are used to pass through the core wire.
According to the type of pressure, the extrusion process can be divided into continuous extrusion and intermittent extrusion.
The former uses a screw extruder and the latter a plunger extruder.
In this screw extruder, the number of screw can be roughly classified as single screw extruder and multi-screw extruder.
The working mechanism of screw extruder is to rely on the pressure and shear force produced by screw rotation, which can make the material fully plasticized and evenly mixed, and molded by die.
So sometimes a single extruder can be used at the same time to complete the mixing, plasticizing and molding a series of processes, so that continuous production.
In addition, the working mechanism of the plunger extruder mainly depends on the plunger pressure, the pre-plasticized material from the die extrusion to achieve the effect of forming.
After extruding the material in the cylinder, the plunger will return and wait until a new round of plasticized material is added before the next round of operation, this production process is discontinuous production.
And the material can not be stirred and mixed, in addition, the production also needs to be pre-plasticized, so in the actual production usually do not often choose this method.
It can only be applied to plastics with extremely low fluidity or high viscosity, such as cellulose nitrate plastics.
Plastic extruder can be classified as twin-screw extruder, single-screw extruder and rare multi-screw extruder and non-screw extruder.
|Screw form||Double-head equal-depth and isometry|
|Length-diameter ratio of screw||1:5.14||4.5:1||4:1|
|KW Motor power||37kw||55kw||110kw|
|Cooling water pressure||0.2-0.4Mpa||0.2Mpa||0.2Mpa|