Views:3 Author:Site Editor Publish Time: 2021-07-02 Origin:Site
Eva extruder relies on the pressure and shear force produced by the screw rotation, which can make the material fully plasticized and evenly mixed, forming through the die. So, what are its specific functions and uses? This article will introduce this knowledge to you.
This paper will start from the following three aspects:
The working principle of eva extruder.
The function of eva extruder.
What is eva extruder used for?
The material enters the barrel from the hopper and is transported to the feeding section through the friction and shear action between the inner wall of the barrel and the surface of the screw under the rotation of the screw. The loose solid is transported forward and compacted in the compression section at the same time. The depth of the screw groove becomes shallow and further compacted. At the same time, it is heated outside the barrel and the friction and shear action between the screw and the inner wall of the barrel.
The homogenization section makes the material uniform, extrudes the melt at a constant temperature, constant weight and constant pressure, and then forms the product at the die head.
Extrusion methods can be classified as follows:
1. According to the plasticizing method: dry extrusion and wet extrusion.
2. Press mode: continuous extrusion and intermittent extrusion.
The function of eva extruder is to melt solid material into melt with uniform temperature and extrude continuously.
According to the state of the material in the extruder and the different functions of each part of the extruder, the extruder barrel can be divided into three functional sections along the screw axis: solid conveying, plasticizing melting and melt conveying. These three functional sections are not completely consistent with the three geometric sections (feeding section, compression section and metering section) of the standard screw. The boundary of the functional section varies with the material properties and process conditions, while the geometric section is fixed. On the one hand, the mass flow rate of any section along the screw groove direction must be kept constant and equal to the output. On the other hand, the conveying rate of melt should be equal to the melting rate of material.
(1) Solid transportation. Solid conveying is the basis of the whole plasticizing extrusion process, and its main function is to transport solid materials to the melting section after compaction.
(2) Melt plasticization. The solid material transported by the feeding section is heated by the heater outside the barrel and the shearing heat of the screw and the material in the melting section of the extruder, then gradually melts and finally completely becomes melt.
(3) Melt transport. Melt conveying starts from the place where the material is completely melted. Its main function is to further mix and homogenize the molten material, and to transport it to the die head to overcome considerable flow resistance.
1. Tube extrusion.
2. Sheet and sheet extrusion.
3. Extrusion of profile.
4. Modified granulation: suitable for EVA plastic blending, modification, reinforced granulation.
The above is some introduction about the use of eva extruder, I believe you have a deeper understanding of eva extruder after reading. Nanjing Haisi is a professional manufacturer of extruders. If you have any other needs, please contact us.