Extrusion system composition of PE three-layer co-extrusion pipe equipment


Ningbo Fangli Technology Co., Ltd. is a mechanical equipment manufacturer with nearly 30 years’ experiences of plastic pipe extrusion equipment, new environmental protection and new materials equipment. Since its establishment Fangli has been developed based on user’s demands. Through continuous improvement, independent R&D on the core technology and digestion & absorption of advanced technology and other means, we have developed PVC pipe extrusion line, PP-R pipe extrusion line, PE water supply / gas pipe extrusion line, which was recommended by the Chinese Ministry of Construction to replace imported products. We have gained the title of “First-class Brand in Zhejiang Province”.

The extrusion system of PE three-layer co extrusion pipe equipment includes screw, barrel, hopper, head and die. The plastic is plasticized into uniform melt through the extrusion system, and is continuously extruded by the screw under the pressure established in this process.


1. Screw: as the most important part, it is directly related to the application scope and productivity of the equipment. It is made of high-strength corrosion-resistant alloy steel.


2. Barrel: it is a metal cylinder, which is generally made of alloy steel with heat resistance, high compressive strength, strong wear resistance and corrosion resistance or composite steel pipe lined with alloy steel. The barrel cooperates with the screw to realize the crushing, softening, melting, plasticization, exhaust and compaction of the plastic, and continuously and evenly transport the rubber to the molding system. Generally, the length of the barrel is 15-30 times of its diameter, which is based on the principle of fully heating and fully plasticizing the plastic.


3. Hopper: the bottom of the hopper is equipped with a cutting device to adjust and cut off the material flow. The side of the hopper is equipped with a sight hole and a calibrated metering device.


4. Machine head and die: the machine head is composed of alloy steel inner sleeve and carbon steel outer sleeve. The machine head is equipped with forming die. The function of the machine head is to convert the rotating plastic melt into parallel linear motion, guide it into the die sleeve evenly and stably, and give the plastic the necessary forming pressure. The plastic is plasticized and compacted in the barrel, and flows into the head forming mold through the neck of the head through a certain flow channel through the porous filter plate. The mold core and mold sleeve are properly matched to form an annular gap with decreasing section, so that the plastic melt forms a continuous and dense tubular coating around the core wire. In order to ensure the reasonable plastic flow channel in the machine head and eliminate the dead corner of accumulated plastic, a shunt sleeve is often arranged. In order to eliminate the pressure fluctuation during plastic extrusion, a pressure equalizing ring is also arranged. The machine head is also equipped with a die correction and adjustment device, which is convenient to adjust and correct the concentricity of the die core and die sleeve.


PE three-layer co extrusion pipe equipment divides the head into oblique head (included angle 120 °) and right angle head according to the included angle between the head material flow direction and the screw centerline. The shell of the machine head is fixed on the machine body with bolts. The mold in the machine head has a mold core seat and is fixed at the inlet port of the machine head with nuts. The front of the mold core seat is equipped with a mold core. The center of the mold core and the mold core seat is provided with holes for passing through the core wire. A pressure equalizing ring is installed at the front of the machine head for equalizing the pressure. The extrusion molding part is composed of a mold sleeve seat and a mold sleeve. The position of the mold sleeve can be adjusted by bolts through support, In order to adjust the relative position of the die sleeve to the die core, it is convenient to adjust the uniformity of the thickness of the extrusion layer. A heating device and a temperature measuring device are installed outside the machine head.


If you need more information, Ningbo Fangli Technology Co., Ltd. welcomes you to contact for a detailed inquiry, we will provide you with professional technical guidance or equipment procurement suggestions.


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