Twin Screw Extruder Working Principle

Twin Screw Extruder Working Principle

Twin Screw Extruder Working Principle in Brief

People use the twin screw extruder machine in the plastic extrusion process. People use it when two or more chemicals are mixed or compounded. Reactive polymeric materials are the ideal candidates for this method of extrusion. A twin screw extruder is especially helpful for producing stiff mixtures of wood fiber and PE. With mixtures, it is used to extrude composite flooring to replace solid wood products, which also greatly protects the damage to the environment. Using a kneading block, forward and reverse capabilities, and other unique mixing features, two screws rotate either in tandem or against one another in this approach.

There are two screws in a twin screw or multi-screw extruder. These screws are extremely effective twin screw extruder working that can process many tons of plastic per hour, despite their diminutive size. Twin screw extrusion equipment’s versatility (The modular design of the screw and barrel, the adjustable screw structure, freely match-able feeding methods, etc)enables it to be specially tailored for the formulation being processed.

For instance, the two screws could be intermeshing or non-intermeshing, co-rotating or counter-rotating. To attain certain mixing qualities, the screw configurations themselves can also be changed utilizing kneading blocks, forward conveying elements, reverse conveying elements, and other designs.

Working principle of co-rotating twin-screw extruder granulator

Two parallel screws that revolve in same directions are contained inside a barrel and make up the twin screw extrusion machine. Via a hopper, the raw material is inserted into the barrel and moved toward the end of the barrel via the screws. The raw material is compressed and heated to a precise temperature range by the screws’ unique design, which turns it into a homogenous combination.

After being pushed through a die, this mixture is cooled to create the intended result. The high degree of mixing and kneading action offered by the twin screw design improves the raw material’s plasticization and homogeneity.

The twin screw extruder working is a highly adaptable and effective method that finds extensive use across multiple sectors. The plasticization and homogeneity of the raw material in the presence of heat and pressure is the basis for the twin screw extruder’s scientific operation.

Small size twin screw extruder VS Large size twin screw extruder

Screw diameter:

To manage higher shear rates, large torque versions have bigger screw diameters—up to 150 mm. Additionally, they have strong motors that produce more torque, enabling them to produce goods at faster rates than small-torque extruders. Small size twin screw extruder occupies a small area, low energy consumption, easy to clean and with characteristics of small torque extruders. They are a cost-effective option for small and medium-sized businesses because they are often compact.


Large torque extruders are commonly employed in the processing of challenging materials, including plastic alloys and large-viscosity compounds. Although they are best suited for continuous production runs using a single material, small torque variants can process resins with lower viscosities.

screw Design:

Large torque twin screw extruders are designed with a longer and more robust screw. This facilitates the production of a greater torque output. Larger-scale production can benefit greatly from the screw’s ability to handle more material due to its stronger and longer screw.
Conversely, the screw of small torque twin screw extruders is weaker and shorter. Its output is thus limited to smaller applications and

materials because it handles less material and produces less torque.

Heat Transfer:

Large torque twin screw extruders usually run quickly and with a lot of torque. They can mix and process materials more quickly thanks to their higher torque output, which increases the amount of heat produced in the barrel.

Small torque twin screw extruders, on the other hand, produce less heat, allowing them to be used for extended periods without overheating. They don’t produce as much heat since they process materials more slowly and with less torque. Furthermore, small torque alternatives reduce the chance of overheating by functioning best in applications that need lower temperature settings to function.

Structural Characteristics of Twin Screw Extruder

The forceful extrusion, excellent quality, significant adaptability, extended service life, higher shear rate. Lower consumption, challenging material decomposition, effective mixing and plasticization, and direct powder molding are some of the features of the twin screw extruder. Its automated temperature control and exhaust vacuum are advantages. It can be used to make silicone profiles, plates, pipelines, and other goods.

The twin screw extruder features a sophisticated “building block” design for both the screw and barrel. The screw is made up of different types of screw blocks that are arranged on a mandrel. To flexibly combine the perfect threaded element construction according to the material variety and other technological needs, the inner liner in the cylinder can be modified by the various screw blocks. It is generally common to balance the needs of a multipurpose machine and accomplish multiple functions with a single machine.

Application Example

Twin screw extruder working have a great capacity, which makes them useful in several industries.

The co-rotating parallel twin screw extruder has smaller clearance/gap, flexible screw and cylinder design, which provides a good platform for the modification, coloring, strengthening and toughening of various plastics, and in the same time,the co-rotating parallel twin screw extruder can control the speed of the screw through the governor, which provides a broader operating space for various reactive mixed extrusion.

If you want know more about twin screw extruder working, welcome to contact us for further information.

About us

Nanjing Granuwel Machinery CO., LTD is specializing in the R&D design and manufacture of high polymer extruders, our team of top-level extrusion professionals provides the right extruder for your exact application.

Nanjing Granuwel Machinery CO., LTD
Nanjing Granuwel Machinery CO., LTD

We possess excellent capability of innovation and product development, and desire to provide the best products for our customers through the improvement of equipment structure and reduction of equipment energy consumption through our practical experiences and technical innovation. 

For any question or inquiry, warmly welcome to contact us!!!

Tel: +86-25-86199956

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