Plastic pipe extrusion die structure


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 head is an important component in the extrusion production line. Its function is to further compact and plasticize the plasticized melt. After shunting, it enters the annular section channel and is cooled and shaped into pipe blank. The pipe extrusion head is divided into three types: straight through head, right angle head (also known as bending head) and lateral head (side head). Among the plastic pipes, polyvinyl chloride (PVC) pipes have the largest output and the widest application. Among them, hard poly (vinyl chloride) (RPVC) pipes account for 75% and soft poly (vinyl chloride) (SPVC) pipes account for 25%. The RPVC pipe head is further introduced below.


1. Straight through head

This type of head axis coincides with the axis of the extruder, which has the advantages of simple structure, easy manufacture, low cost and low material flow resistance; This extrusion head has the disadvantages of difficult heating of mandrel and low strength of pipe at the joint line caused by diverter support.


2. Right angle head

The mandrel end of this structure is the support end. Since there is no diverter support, the molten material enters from the head end to the opposite side of the mandrel and collects, and only one suture may be generated. In addition to pipes, the right angle head can also produce wire and cable products, which has the advantages of easy core mold heating and suitable for extruding pipes by inner diameter setting method; However, it also has some disadvantages, such as complex structure, difficult mandrel design, high manufacturing cost, large material flow resistance and so on.


3. Lateral head

The material flow from the extruder first flows through a curved channel and then enters the head side. The material flow wraps the mandrel and flows out along the head axis. This design can not only make the extrusion direction of the pipe at any angle with the extruder, but also parallel to the screw axis of the extruder. It is suitable for high-speed extrusion of large-diameter pipe, but the structure of the head is complex and the cost is high.


4. Other forms of heads

Other types of extrusion heads include screen plate pipe extrusion head, coating pipe extrusion head, coating pipe extrusion head, mandrel rotary extrusion head, etc. The mandrel rotary head uses ordinary polymer particles to mix a certain length of glass fiber online after its plasticization and melting, and makes the melt molecules and glass fiber spirally oriented along the pipe wall of the extruded circular pipe to produce pipes with higher strength, which can meet the needs of engineering practice.


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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