What is the function of the barrel? What are the characteristics of the 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”.



What is the function of the barrel in the extrusion system?


The barrel includes a screw, which rotates in the barrel. When the screw rotates and the thread is pushed, the heat is transmitted to the material by heating outside the barrel. In addition, the volume of the thread is gradually reduced, so that the material is evenly mixed and plasticized into a molten viscous flow state after being subjected to various forces such as extrusion, turnover and shear, so as to complete the plasticization of the material. The matching work of the barrel and screw ensures the normal extrusion work of the extruder.


What are the common structures of barrel? What are the characteristics of each?


The common structures of barrel include integral type, sectional type, bushing and bimetallic layer type.


1. The integral structure barrel is widely used in extruder, especially when the specification of extruders are small, it is generally used. The barrel is convenient for the arrangement of heating and cooling devices, easy to ensure temperature control and high machining accuracy.


2. The segmented structure barrel is mainly used in larger extruders and exhaust extruders. Because the barrel is divided into several sections, the length of each section of the barrel is small, which brings convenience to machining; however, the inner diameter dimension and concentricity accuracy of several sections of barrel are difficult to achieve unity; in addition, the segmented barrel is connected with flange, which brings some difficulties to the arrangement of heating and cooling devices of the barrel, and the temperature control of heating and cooling will not be too uniform.


3. The inner diameter of the barrel is lined or cast with wear-resistant alloy. In order to save valuable alloy steel, the barrel of larger extruders is usually formed with cast steel, and then the wear-resistant alloy bushing is added or a layer of wear-resistant alloy material is cast after finishing the inner hole.


The application of lined sleeve barrel or casting a layer of wear-resistant alloy barrel in large extruder not only saves a lot of valuable alloy steel and reduces the equipment manufacturing cost, but also creates convenient conditions for barrel maintenance in the future: when the barrel alloy bushing is seriously worn, the barrel can work normally as long as the bushing is replaced, which saves equipment maintenance time.


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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