Extruder Also Belong To One Of The Types Of Plastic Machinery

The extruder can be divided into continuous extrusion and discontinuous extrusion according to the type of action. According to the direction of the head flow and the angle of the screw center line, the machine head is divided into bevel head (angle 120 °) and right angle head The The head of the nose is fixed with bolts on the fuselage, the mold inside the die has a core sitting, and fixed with a nut in the nose into the line port, the core seat in front of a core, core and core The center has holes for passing through the core. Plastic extruder is also a kind of plastic machinery.

Plastic extruders are also one of the types of plastic machinery. Extruder according to the direction of the head material and the angle of the screw center line, the machine can be divided into right angle head and bevel nose and so on. The head of the shell is usually bolted to the fixed on the fuselage, the head of the mold inside the mold core seat, and then use the nut to be fixed in the nose of the nose port, the core seat is also equipped with And the center of the mandrel and the mandrel has holes which act on the core. Depending on the type of pressurization, the extrusion process can be divided into two types: continuous extrusion and intermittent extrusion. The former equipment used for the screw extruder, the latter equipment for the plunger extruder. In this screw extruder can be roughly by virtue of the number of screws for the single screw extruder and multi-screw extruder.

The working mechanism of the screw extruder depends on the pressure and shear force produced by the rotation of the screw, which allows the material to be fully plasticized and evenly mixed and molded by die; sometimes it can be done at the same time using an extruder Mixing, plasticizing and molding a series of processes, so as to continuous production. In addition, the working mechanism of the plunger extruder is mainly by the use of plunger pressure, the first plastic material in advance from the die extrusion to achieve the effect of forming. The material in the material cylinder after the extrusion out of the plunger will return to wait until the addition of a new round of plastic materials and then the next round of operation, this production process is discontinuous production, and the basic material can not be fully stirred As well as the mixing, in addition to the production of pre-plasticization, so the actual production is usually not often used in this method, can only be applied to the poor mobility or viscosity is very large plastic, like nitrocellulose plastic this Plastic products of the molding process.

The plastic extruder can be classified as a twin screw extruder, a single screw extruder, and a rare multi-screw extruder and a screwless extruder.

Mechanical principle

Add water or a suitable liquid to the raw material powder and keep stirring. Mix the material with a high extrusion pressure from the porous head or metal mesh.

Usually the material is put into a cylindrical container and the material is extruded with a screw. After using the frequency conversion technology, the pressure can be controlled so that the most suitable linear velocity can be selected.

Single screw extruder principle

Single screw is generally divided into three sections in the effective length, according to the screw diameter size screw pitch to determine the effective length of three sections, generally divided by one third of each division.

The last thread of the mouth is called the conveyor section: the material is not required to be plasticized here, but it is necessary to preheat and press the squeeze. In the past, the old extrusion theory thought that the material was loose and later proved that the material Solid plug, that is, after the material is squeezed by a solid like a plug, so as long as the completion of the delivery task is its function.

The second paragraph is called the compression section, at this time the volume of the groove from the big gradually smaller, and the temperature to achieve the degree of plastic material, where the compression generated by the transport section of three, here compressed to a, this is called the screw compression ratio - 3: 1, some machines have changed to complete the plasticized material into the third paragraph.

The third paragraph is the measurement section, where the material to maintain the plastic temperature, just as metering pumps as accurate and quantitative delivery of melt materials to supply the head, this time the temperature can not be lower than the plastic temperature, generally slightly higher.