Plastic granulator work principle and basic technique

    The reasonable choice of plastic granulator / plastic recycling machine  is to determine the standard of particle quality, worth learning and research! Shanghai Duxia Industry & Trade Co., Ltd. will introduce the working principle and basic techniques of plastic granulator:

Plastic granulator / Plastic Recycling Machine basic information

    The host of the plastic granulator is an extruder, which consists of an extrusion system, a transmission system, and a heating cooling system.

    1. Extrusion system, the extrusion system includes a screw, a barrel, a hopper, a head, and a mold, and plastic is plastic into a uniform melt by an extrusion system, and under pressure established in this process, the screw is continuous Extruder head.

(1) Screw: It is the most important part of the extruder, which is directly related to the application range and productivity of the extruder, made of high-intensity corrosion-resistant alloy steel.

(2) Basegu: It is a metal cylinder, which is generally made of a composite steel pipe that is highly resistant to heat, pressure resistance, rugged, resistant, and corrosion-resistant alloy steel or liner-lined with gold steel. The barrel is fitted with the screw to achieve pulverization, softening, melting, plasticizing, exhaust, and compaction of the plastic, and continuously transporting the compound to the molding system. Generally, the length of the barrel is 15 to 30 times its diameter, so that plastics are sufficiently heated and plastically placed as principles.

(3) Bouss: The bottom of the hopper is equipped with a truncated device to adjust and cut the stream, and the side surface of the hopper is equipped with a visual hole and a calibration metering device.

(4) Head and mold: The head is composed of alloy steel inner sleeves and carbon steel jackets, and the mold is equipped with a molded mold. The action of the head is to convert the plastic melt of the rotational movement into parallel linear motion, uniformly and smooth introduction moldings, and impart the necessary molding pressure. The plastic is plasticized in the cartridge. The mechanical head neck flows into the head molding die through the porous filter plate, and the core mold is properly cooperated, forming the continuous reduced annular voids in the section, so that the plastic melt is A continuous dense tubular coating around the core wire. In order to ensure reasonable in the machine head, eliminate the dead angle of the plastic, often resettle the split sleeve to eliminate the pressure fluctuations in the elimination of plastic extrusion, and also provide average rings. The machine is also equipped with a mandrel correction and adjustment device for easy adjustment and correction of the core and mold set.

2. Transmission system

    The effect of the drive system is to drive the screw, which is usually composed of the torque and rotational speed required for the screw in the extrusion process, typically consist of a motor, a speed reducer, and a bearing.

3. Heating the cooling device

Heating and cooling is the necessary conditions that the plastic extrusion process can be performed.

(1) Now the extruder is usually used by electric heating, divided into resistance heating and induction heating, and heated sheets are installed in the body, the charm, and the head of the head. The heating device is heated in the outer heating cylinder to warm the temperature to achieve the temperature required for the process operation.

(2) The cooling device is provided to ensure the temperature range of the plastics in the process required. Specifically, it is to exclude the excess amounts of shear friction generated by the screw rotation to avoid the temperature of the temperature to make plastic decomposition, focal or stereotype. The cartridge cooling is divided into two kinds of water cooling and air-cooled. Generally, the small and medium extruder is suitable for the air-cooled, and the large amount of water is used to combine cooling; the screw cooling mainly uses the center water cooling, the purpose is to increase material solid delivery rate , Stabilize the glue, while improving product quality; but cooling at the hopper, one is to strengthen the conveying effect of solid materials, preventing the plastic particles from sticking to blocked, and the second is to ensure the normal operation of the transmission part.


Inverter in plastic granulator

1, low frequency torque, stable output

2, high control accuracy

3, high performance vector control

4, RS485 serial interface to implement multiple controls

5, can replace DC speed control and servo control

Auxiliary equipment

    The auxiliary machine of the plastic granulation unit mainly includes a disposing device, a school-straight device, a preheating device, a cooling device, a traction device, a meter, a spark test, a tapping device. The use of the extruded unit is different from the auxiliary equipment of its selection. Such as cutters, hair dryers, printing devices, etc.

Correction device:

    The most common type in the type of plastic extrusion is eccentric, and the curvature of various types of cores is one of the important causes of insulation ecception. In the sheath extrusion, the scratch of the sheath surface is often caused by the bending of the cable core. Therefore, the school straight devices in various extruded units are indispensable. The main types of the collections include: roller (divided into horizontal and vertical); pulley type (divided into single slide and pulley set); mesh type, combined with drag, school straight, stable tension and other roles; Pressure wheel (divided into horizontal and vertical), etc.

Preheating device

    Cable core preheating is necessary for insulating extrusion and sheath extrusion. For insulating layers, especially thin layer insulation, the presence of the pores cannot be allowed, and the core can thoroughly remove the surface of the surface by high temperature preheating prior to extruding bag. For jacket squeezing, its main role is to dry the cable core to prevent the possibility of air holes in the sheath due to moisture (or moisture around the bag). Preheating also prevents the plastic in extrusion from being quenched by quenching and residual internal pressure. During the extrusion, the preheating can eliminate the cold wire to enter the high temperature head, and the disparity temperature difference formed at the time of contact with plastic, avoid fluctuation of the plastic temperature, thereby stabilizing the extrusion amount, guarantee Extrusion quality. In the extruder group, electric heating wire is used to pre-heat the heat, and there is sufficient capacity and to ensure rapid temperature rise, and the wire core is high heat and the cable core drying efficiency is high. The preheating temperature is constrained by the speed of the release, which is generally similar to the head temperature.

Cooling device

     The molded plastic extruded layer should be cooled immediately after leaving the head, otherwise it will be deformed under the action of gravity. The cooling method is usually used in water cooling, and is divided into emergency and cold according to the water temperature. The quenched is that cold water is directly cooled. The quenching is advantageous for the plastic extrusion layer, but for the crystalline highlighter, due to the heat cooling, it is easy to residue internal stress inside the extruded tissue, resulting in cracking during use, general PVC The plastic layer is quenched. Clever is to reduce the internal stress of the article, place water in different temperatures in the cooling sink, so that the product gradually cools the form, and the extrusion of PE and PP is carried out, that is, through hot water, warm water, cold water. Three sections of cooling.

Control System

    Plastic granulator control systems include heating systems, cooling systems, and process parameter measurement systems, which are mainly composed of electrical, meter, and execution agencies (ie, control screens and console). Its main role is: control and regulating the drag motor of the main aircraft, outputting the speed and power in line with the process, and can make the main aircraft to work; detect and regulate the temperature, pressure, flow rate of plastic in the extruder; Control or automatic control of the entire unit. Electrical control of the extruder set is roughly divided into two parts: transmission control and temperature control, and realizes control of the extruded process including temperature, pressure, screw rotation, screw cooling, cylinder cooling, product cooling, and traction speed. , Neat line and ensure the constant tension control of the empty disk to the full disk on the tapping.

    Shanghai Duxia Industry and Trade Co., Ltd. is an enterprise focusing on manufacturing plastic packaging machinery.The main products of Shanghai Duxia Industry and Trade Co., Ltd .: film blowing machine,stretch film blowing machine, printing machine, plastic bag making machine, plastic recycling machine.If you need any of the above machines, please leave your information. Our sales will contact you as soon as possible.

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