How does a twin screw extruder work?
Publish Time: 2022-04-29 Origin: Site
Twin screw extruders are developed on the basis of single-screw extruders and have been widely used in the molding and processing of extruded products because of their good charging performance, mixing and plasticizing performance, exhaust performance, and extrusion stability. To understand the working principle of twin screw extruder, we must first have some knowledge of the structure of twin screw extruder. This article provides a brief introduction to the structure and principles of twin screw extruders.
The following is a list of contents
The structure and types of twin screw extruders
How does a twin screw extruder work?
The structure and types of twin screw extruders
The twin screw extruder is composed of several parts, such as the transmission unit, the feeding unit, the barrel, and the screw, and the role of each part is similar to that of the single-screw extruder. The difference from the single-screw extruder is that the twin screw extruder has two parallel screws in a "∞" shaped cross-section.
Twin screw extruders for profile extrusion are usually closely meshed and rotate in opposite directions, although a few use co-rotating twin-screw extrusion. High-speed co-rotating twin screw extruders are used for blending, venting, or as continuous chemical reactors, with maximum screw speeds ranging from 300-600 r/min. extruder, although the two are fundamentally different.
How does a twin screw extruder work?
From the point of view of the principle of motion, the twin screw extruder is different from the isotropic, heterotropic, and non-meshing types.
Co-engaging twin screw extruders
These extruders are available at both low and high speeds, the former being used mainly for profile extrusion, while the latter is used for specialty polymer processing operations.
l Close-meshing extruders. Low-speed extruders with close-meshing screw geometry, where the profile of one screw is closely matched to the profile of the other screw, i.e., a conjugate screw profile.
l Self-cleaning extruder. High-speed co-rotating extruders have a closely matched screw profile. This screw can be designed to have a fairly small screw gap, so that the screw has a closed self-cleaning effect, and this twin screw extruder is called a tight self-cleaning co-rotating twin screw extruder.
Anisotropic twin screw extruder
The tightly meshed anisotropic twin screw extruder has a small gap between the two screw grooves (much smaller than that in a co-engaged twin screw extruder), so that a positive conveying characteristic can be achieved.
Non-Engaging twin screw extruders
The center distance between the two screws of a non-engaging twin screw extruder is greater than the sum of the radii of the two screws.
Nanjing Haisi Extrusion Equipment Co., Ltd. is a high-tech enterprise consisting of a team with many years of experience in R&D, design, manufacturing technology, sales, and service in the extruder industry. We now mainly focus on developing high activity single screw, twin screw, and compound extruders, along with complete factory manufacturing and related technologies. According to the material system and process flow, we realize the optimization of mixing equipment structure design, combining electromechanical and technical systems into one, fully reflecting our years of experience and comprehensive technology. Our production range includes single-screw extruders, co-rotating twin-screw compound extruders, auxiliary equipment, etc. If you are interested in our products, welcome to contact us!