The composition of plastic extruder

1. The extrusion system

Extrusion system, including screw, barrel, hopper, the nose, and mold, plastic plastic into homogeneous melt by extrusion system, and established in the process, under pressure by screw continuous extrusion head.

Screw (1) : is the main component of the squeeze molding machine, it is directly related to squeeze molding machine and the application scope of productivity, is made from high strength and corrosion resistance of alloy steel.

(2) the barrel: is a metal cylinder, generally with heat resistant, high crushing strength, strong wear resistance, corrosion resistance of alloy steel or lining made of alloy steel composite pipe. Barrel and screw, implementation of plastic crushing, softening and melting and plasticizing, exhaust and compaction, and to the continuous uniform conveying rubber molding system, general barrel length to diameter of 15 ~ 30 times, in order to make fully heating and plastic

Points into principle.

(3) the hopper: at the bottom of the hopper is equipped with cutting device, in order to adjust and stop the flow of material, the side of the hopper is equipped with sight hole measuring device and calibration.

And mould (4) the nose: the nose consists of alloy steel inner sleeve and carbon steel jacket, in a forming die head, is the role of head rotation movement of the plastic melt into a parallel straight line, import the die set is steady, and give necessary to plastic molding pressure, plastic plasticizing compaction in the barrel, is approved by the flow of porous filter plate along a certain head neck into the head forming die, die core die set appropriate coordination, the formation of cross section and decreases the annular space, make the plastic melt around the conductor to form a continuous solid tubular cladding layer. In order to ensure the nose in plastic flow is reasonable, eliminate accumulated plastic corner, placed tend to have a split sleeve, to eliminate the plastics extrusion pressure fluctuations, also has a set of equalizing ring. The nose is also equipped with mold correction and adjustment device, easy adjustment and calibration mould core and mould of concentricity, equalizing ring in the front of the nose, balance the pressure; Extrusion molding package part is composed of die sleeve and die set, the location of the die set can be made of bolt support to adjust, to adjust the die set of the relative position of mold core, easy to adjust the uniformity of extrusion cladding thickness. Starting from an external is equipped with heating device and temperature measuring device.

2. The drive system

The function of transmission system is driven screw, supply the screw in the required torque and rotational speed in the process, usually composed of motor, reducer and bearing, etc.

In the similar structure under the premise of a reducer manufacturing costs roughly and its appearance is proportional to the size and weight. Because the shape and weight of the speed reducer, means making use of materials, the use of bearing is bigger, also increase the manufacture cost.

Same diameter screw extruder, high-speed and efficient 65 extruder is more than the energy dissipations of the conventional extrusion machine, motor power increase twice, and the signs of the corresponding number increasing is a must. But higher screw speed, mean low reduction ratio. The same size reducer, low reduction ratio compared with the big reduction ratio, gear modulus increases, reducer increase the load ability. So the increase of the volume weight of the speed reducer, not proportionate to the motor's power increases linearly. If made the denominator, extrusion amount divided by the weight of the gearbox, high-speed and efficient extrusion machine will take small, regular extruder counting.

In the unit output, high speed high efficiency extruder small motor power and the weight of reducer, means that the high efficient 65 extruder machine manufacturing cost per unit of production is lower than common extruder.

3. The heating cooling device

Heating and cooling is plastic extrusion process can be a necessary condition.

(1) now squeeze molding machine with electric heating, usually divided into resistance heating and induction heating, heating tablets in the fuselage, machine neck, in all parts of the nose. Heating device by the plastic inside the external heating tube, heating, in order to achieve the temperature of the process operation need.

(2) the cooling device is to ensure that the plastic in the temperature range of technical requirement. Specifically to rule out the screw rotating the excess heat generated by the shear friction, in order to avoid high temperature make plastic decomposition, charred or difficult to finalize the design. Barrel cooling into the water and air cooling two, general small and medium-sized squeeze molding machine adopts air cooling is more appropriate, large use water more or two forms combined with cooling; Screw water cooled mainly adopts center, the purpose is to increase the rate of solid conveying material, the quantity of adhesive stability, improve the quality of products at the same time; But the cooling in the hopper, one is to strengthen the transport of solid materials, prevent make jam the material plastic grains sticky with heating, 2 it is to guarantee the normal work of the transmission parts.

Auxiliary equipment

Plastic extrusion of the unit 65 auxiliary machine mainly includes pay-off device, straightening device, preheating device, cooling device, traction device, the meter machine, sparks machine, take-up device. Extrusion unit USES the different matching varies with auxiliary equipment, such as cutter, blow dry device, printing equipment, etc.

Straightening device

Plastic extrusion waste is one of the most common eccentric type, and various types of bending line core is one of the important reasons for the insulation eccentricity. In sheathed extrusion, scratches on the surface of the sheath tend to be caused by a cable bending. Therefore, all kinds of straightening device is essential in squeeze molding machine group. Straightening device of the main types are: drum (divided into horizontal and vertical); Pulley (divided into single block and block and tackle); Ground wheel, and a variety of action such as drag, straightening and stable tension; Pressure wheel (divided into horizontal and vertical), etc.

Preheating device

Preheat for insulation extrusion and cable core sheathed extrusion is necessary. For insulation, especially the thin layer of insulation, can not allow the existence of the porosity, wire core before extruded through high temperature preheating can completely remove the surface of the water and oil. For sheathed extrusion, the main function is to dry the cable core, prevent the moisture (or winding and the moisture content in the cushion layer) role in the sheath may appear porosity. Preheating can also prevent extrusion plastic due to quenching residual stress in the role. In the process of extrusion plastic, preheating can eliminate cold line into the nose by high temperature, in gate in contact with the plastic forming of wide temperature difference, avoid plastic temperature fluctuations caused by extrusion pressure fluctuations, thus stable extrusion quantity, ensure the quality of extrusion. Group extrusion molding machine adopts electric hotline core preheating device, have enough capacity required and ensure warming rapidly, make the line core preheating and core drying efficiency is high. The restriction of the feeding speed, preheat temperature is similar with the nose temperature.

Cooling device

Molding of plastic extrusion cladding after leaving the nose, should immediately after heating, otherwise it will happen in the under the action of gravity deformation. Usually adopts water cooling, cooling way and according to the water temperature is different, divided into mild cold. Quenching is cold water cooling, direct quenching is good for plastic extrusion cladding to finalize the design, but for crystal polymer, because of the sudden heat cooling, easy in extrusion cladding organization internal residual stress, leading to cracks in the course of using, general PVC plastic layer by rapid cooling. Slow cooling is to reduce the internal stress of products, block placed different temperature of the water in the cooling water tank, cooling the products gradually to finalize the design, extrusion of PE, PP, with a slow cooling which three sections of cooling after hot water, warm water, cold water.

1. The extrusion system

Extrusion system, including screw, barrel, hopper, the nose, and mold, plastic plastic into homogeneous melt by extrusion system, and established in the process, under pressure by screw continuous extrusion head.

Screw (1) : is the main component of the squeeze molding machine, it is directly related to squeeze molding machine and the application scope of productivity, is made from high strength and corrosion resistance of alloy steel.

(2) the barrel: is a metal cylinder, generally with heat resistant, high crushing strength, strong wear resistance, corrosion resistance of alloy steel or lining made of alloy steel composite pipe. Barrel and screw, implementation of plastic crushing, softening and melting and plasticizing, exhaust and compaction, and to the continuous uniform conveying rubber molding system, general barrel length to diameter of 15 ~ 30 times, in order to make fully heating and plastic

Points into principle.

(3) the hopper: at the bottom of the hopper is equipped with cutting device, in order to adjust and stop the flow of material, the side of the hopper is equipped with sight hole measuring device and calibration.

And mould (4) the nose: the nose consists of alloy steel inner sleeve and carbon steel jacket, in a forming die head, is the role of head rotation movement of the plastic melt into a parallel straight line, import the die set is steady, and give necessary to plastic molding pressure, plastic plasticizing compaction in the barrel, is approved by the flow of porous filter plate along a certain head neck into the head forming die, die core die set appropriate coordination, the formation of cross section and decreases the annular space, make the plastic melt around the conductor to form a continuous solid tubular cladding layer. In order to ensure the nose in plastic flow is reasonable, eliminate accumulated plastic corner, placed tend to have a split sleeve, to eliminate the plastics extrusion pressure fluctuations, also has a set of equalizing ring. The nose is also equipped with mold correction and adjustment device, easy adjustment and calibration mould core and mould of concentricity, equalizing ring in the front of the nose, balance the pressure; Extrusion molding package part is composed of die sleeve and die set, the location of the die set can be made of bolt support to adjust, to adjust the die set of the relative position of mold core, easy to adjust the uniformity of extrusion cladding thickness. Starting from an external is equipped with heating device and temperature measuring device.

2. The drive system

The function of transmission system is driven screw, supply the screw in the required torque and rotational speed in the process, usually composed of motor, reducer and bearing, etc.

In the similar structure under the premise of a reducer manufacturing costs roughly and its appearance is proportional to the size and weight. Because the shape and weight of the speed reducer, means making use of materials, the use of bearing is bigger, also increase the manufacture cost.

Same diameter screw extruder, high-speed and efficient 65 extruder is more than the energy dissipations of the conventional extrusion machine, motor power increase twice, and the signs of the corresponding number increasing is a must. But higher screw speed, mean low reduction ratio. The same size reducer, low reduction ratio compared with the big reduction ratio, gear modulus increases, reducer increase the load ability. So the increase of the volume weight of the speed reducer, not proportionate to the motor's power increases linearly. If made the denominator, extrusion amount divided by the weight of the gearbox, high-speed and efficient extrusion machine will take small, regular extruder counting.

In the unit output, high speed high efficiency extruder small motor power and the weight of reducer, means that the high efficient 65 extruder machine manufacturing cost per unit of production is lower than common extruder.

3. The heating cooling device

Heating and cooling is plastic extrusion process can be a necessary condition.

(1) now squeeze molding machine with electric heating, usually divided into resistance heating and induction heating, heating tablets in the fuselage, machine neck, in all parts of the nose. Heating device by the plastic inside the external heating tube, heating, in order to achieve the temperature of the process operation need.

(2) the cooling device is to ensure that the plastic in the temperature range of technical requirement. Specifically to rule out the screw rotating the excess heat generated by the shear friction, in order to avoid high temperature make plastic decomposition, charred or difficult to finalize the design. Barrel cooling into the water and air cooling two, general small and medium-sized squeeze molding machine adopts air cooling is more appropriate, large use water more or two forms combined with cooling; Screw water cooled mainly adopts center, the purpose is to increase the rate of solid conveying material, the quantity of adhesive stability, improve the quality of products at the same time; But the cooling in the hopper, one is to strengthen the transport of solid materials, prevent make jam the material plastic grains sticky with heating, 2 it is to guarantee the normal work of the transmission parts.

Auxiliary equipment

Plastic extrusion of the unit 65 auxiliary machine mainly includes pay-off device, straightening device, preheating device, cooling device, traction device, the meter machine, sparks machine, take-up device. Extrusion unit USES the different matching varies with auxiliary equipment, such as cutter, blow dry device, printing equipment, etc.

Straightening device

Plastic extrusion waste is one of the most common eccentric type, and various types of bending line core is one of the important reasons for the insulation eccentricity. In sheathed extrusion, scratches on the surface of the sheath tend to be caused by a cable bending. Therefore, all kinds of straightening device is essential in squeeze molding machine group. Straightening device of the main types are: drum (divided into horizontal and vertical); Pulley (divided into single block and block and tackle); Ground wheel, and a variety of action such as drag, straightening and stable tension; Pressure wheel (divided into horizontal and vertical), etc.

Preheating device

Preheat for insulation extrusion and cable core sheathed extrusion is necessary. For insulation, especially the thin layer of insulation, can not allow the existence of the porosity, wire core before extruded through high temperature preheating can completely remove the surface of the water and oil. For sheathed extrusion, the main function is to dry the cable core, prevent the moisture (or winding and the moisture content in the cushion layer) role in the sheath may appear porosity. Preheating can also prevent extrusion plastic due to quenching residual stress in the role. In the process of extrusion plastic, preheating can eliminate cold line into the nose by high temperature, in gate in contact with the plastic forming of wide temperature difference, avoid plastic temperature fluctuations caused by extrusion pressure fluctuations, thus stable extrusion quantity, ensure the quality of extrusion. Group extrusion molding machine adopts electric hotline core preheating device, have enough capacity required and ensure warming rapidly, make the line core preheating and core drying efficiency is high. The restriction of the feeding speed, preheat temperature is similar with the nose temperature.

Cooling device

Molding of plastic extrusion cladding after leaving the nose, should immediately after heating, otherwise it will happen in the under the action of gravity deformation. Usually adopts water cooling, cooling way and according to the water temperature is different, divided into mild cold. Quenching is cold water cooling, direct quenching is good for plastic extrusion cladding to finalize the design, but for crystal polymer, because of the sudden heat cooling, easy in extrusion cladding organization internal residual stress, leading to cracks in the course of using, general PVC plastic layer by rapid cooling. Slow cooling is to reduce the internal stress of products, block placed different temperature of the water in the cooling water tank, cooling the products gradually to finalize the design, extrusion of PE, PP, with a slow cooling which three sections of cooling after hot water, warm water, cold water.