In recent years, for all aspects of the plastics manufacturing industry environment requirements are becoming more and more stringent, for the plastic manufacturing production equipment also puts forward a challenge, today by the Nanjing Suminoe Precision Machinery Co., Ltd. to lead us to navigate the basic composition of plastic pelletizing machine.

Plastic pelletizing machine is the host extruder system, which consists of extrusion system, transmission system and heating and cooling system.


First, the host equipment

1, extrusion system:

Extrusion system includes screw, barrel, hopper, head, and die, plastic through the extrusion system and plasticized into a uniform melt, and in the process of establishing pressure, by the screw continuous extrusion head.


(1) screw: is the most important part of the extruder, it is directly related to the scope of application of the extruder and production efficiency, made of high-strength corrosion-resistant alloy steel.

(2) barrel: is a seamless metal tube, generally heat-resistant, pressure-resistant high strength, strong wear-resistant, corrosion-resistant alloy steel or alloy steel lined with composite steel pipe made. Cylinder and screw with the realization of the plastic crushing, softening, melting, plasticizing, exhaust and compaction, and to the molding system for continuous and uniform delivery of rubber. General length of the barrel for its diameter of 18:1, so that the plastic is fully heated and fully plasticized as a principle.

(3) Hopper: the bottom of the hopper is equipped with a cut-off device to adjust and cut off the flow of material, and the side of the hopper is equipped with sight holes and calibrated measuring devices.

(4) Head and mold: the head consists of alloy steel inner sleeve and carbon steel outer sleeve, the head is equipped with molding die. The role of the head is to convert the rotary motion of the plastic melt into parallel linear motion, uniform and smooth introduction into the mold set, and give the plastic to the necessary molding pressure. Plastic in the barrel plasticization compaction, through the porous filter plate along a certain flow channel through the neck of the head into the head molding mold, mold core mold sleeve appropriate coordination, the formation of the cross-section of the ever-decreasing annular gap, so that the plastic melt in the core line around the formation of a continuous and dense tubular cladding layer. In order to ensure a reasonable plastic flow path in the head, to eliminate the dead space of the accumulated plastic, often placed on the manifold (sleeve), in order to eliminate pressure fluctuations in the plastic extrusion, there are also set up pressure equalization ring. The head is also equipped with mold calibration and adjustment devices, easy to adjust and correct the concentricity of the die core and die set. Extruder according to the head material flow direction and the screw centerline angle, the head will be divided into oblique angle head (120 degrees) and right angle (90 degrees) head. The shell of the head is bolted to the body of the machine, the mold in the head has a die core sitting, and fixed with a nut in the head inlet port, the front of the die core seat is equipped with a die core, die core and die core seat in the center of the hole, for passing through the core; in the front of the head is equipped with an equalizing ring for equalizing the pressure; extrusion molding part consists of a die set seat and die set, the position of the die set can be adjusted by the bolts through the support to adjust the relative position of the die set to the core, easy to adjust the relative position of the extrusion molding part consists of a die set seat and die sets, die set position can be adjusted by the bolts through the support to adjust the die set to the core The position of the die sleeve can be adjusted by the bolt through the support to adjust the relative position of the die sleeve to the die core, which is convenient to adjust the uniformity of the thickness of the extruded layer. The machine head is equipped with heating device and temperature measuring device.
Transmission system:


The function of transmission system is to drive the screw and supply the torque and speed required by the screw in the process of extrusion, which usually consists of electric motor, reducer and bearings.

3. Heating and cooling device: heating and cooling are necessary conditions for the plastic extrusion process to be carried out.

(1) now extrusion machine is usually used for electric heating, divided into resistance heating and induction heating, heating pads installed in the body, the neck, the head of each part. The heating device heats the plastic in the cylinder from the outside to warm it up to reach the temperature required for the process operation. (2) The cooling device is set up to ensure that the plastic is at the temperature range required by the process. Specifically, it is to exclude the excess heat generated by the shear friction of the rotating screw, in order to avoid the high temperature of the plastic decomposition, scorching or shaping difficulties. Barrel cooling is divided into water-cooled and air-cooled two kinds, generally small and medium-sized extruder using air-cooled is more appropriate, large-scale water-cooled or a combination of the two forms of cooling; screw cooling is mainly used in the center of the water-cooled, the purpose is to increase the rate of material solids transport, stabilize the amount of rubber, while improving product quality; but the cooling at the hopper, one is to strengthen the role of solid material transport, to prevent the plastic particles due to the temperature of the viscous plastic clogging However, the cooling at the hopper is to strengthen the conveying effect on the solid materials and prevent the plastic particles from sticking and clogging due to the warming.