Types of Twin Screw Extruder

What is Twin Screw Extruder

Screw extruders can be divided into single-screw extruders, twin-screw extruders and multi-screw extruders according to the number of screws. At present, single-screw extruders are mainly used for extrusion processing of general materials.

The twin-screw extruder is developed on the basis of the single-screw extruder. Due to its good feeding performance, mixing and plasticizing performance, exhaust performance, extrusion stability, etc., it has been widely used in the extrusion product forming process.

It consists of several parts such as a transmission device, feeding device, barrel, and screw. The function of each part is similar to that of a single-screw extruder. The difference from a single-screw extruder is that there are two parallel screws. Twin-screw extruders have been greatly developed in recent years, and various types of twin-screw extruders have been serialized and commercialized.

Features of twin screw extruder

1. It is easy to add materials. Because the twin-screw extruder transports materials by the principle of positive displacement. Therefore, materials with high or low viscosity, as well as ribbons, pastes, powders, etc., can be added.

2. The material has a short residence time in the twin-screw extruder, and the residence time distribution is narrow. Therefore, twin-screw extruders are more suitable for processing heat-sensitive materials.

3. Excellent exhaust performance. This is due to the self-cleaning function of the meshed double screw shaft, which enables the material to obtain a complete surface renewal in the exhaust section.

4. Excellent mixing, and plasticizing effect.

5. Lower power consumption. The power consumption of a twin-screw extruder is about 30% lower than that of a single-screw extruder, which makes a twin-screw extruder have obvious advantages in energy saving and consumption reduction.

Types of twin screw extruder

1. According to the relative orientation of the two axes, there are parallel and conical points;

PVC Conical Twin Screw Extruder

2. According to the meshing procedure of two screws, there are meshing types and non-meshing types;

3. According to the rotation direction of the two screws, there are the same direction and the opposite direction, and there are inward and outward points in the opposite direction;

Co-rotating Twin Screw Extruder

Counter Rotating Twin Screw Extruder

4. According to the rotation speed of the screw, there are high-speed and low-speed points;

5. According to the structure of the screw and barrel, there are whole and combination points.

Working principle of co-rotating twin screw extruder

1. Forced transportation. In meshing co-rotating twin screws, the two screws move in opposite directions at the meshing place, one screw pulls the material into the meshing gap, the other screw pushes the material out, and the material transfers from one screw groove to another screw groove, Material is forcibly conveyed.

2. Averaging and mixing. Tongxiang rotary twin-screw has a small gap at the meshing place, the movement direction of the screw rib and the screw groove is opposite, and the speed is high, so the meshing place has a high shearing speed and a large shearing force, so the mixing effect is better.

3. Self-cleaning. Due to the high shearing speed, it can scrape off the material stuck on the screw, so it has a very good self-cleaning effect and is not easy to cause local degradation and deterioration.

4. Compression of materials. There are many ways to compress materials by the co-rotating twin-screw extruder, and the comprehensive effect is better.

5. Feeding and exhausting. The co-rotating twin-screw extruder requires uniform and quantitative feeding. Using the metering method, a large lead screw conveying element can be used, so that the screw groove is not filled and the pressure is zero so that the exhaust hole can be set.

Main application areas of twin screw extruders

Biodegradable Plastic Extrusion Machine

Plastic is one of the best modern human inventions over the past 100 years, bringing unparalleled benefits to humankind. However, given its durability and longevity, plastic waste becomes a huge challenge for a greener, better world.

Biodegradable Plastic Extrusion Machine

Plastics extrusion is a high-volume manufacturing process in which raw plastic material is melted and formed into a continuous profile. Extrusion produces items such as pipe/tubing, weather stripping, fence, deck railing, window frames, adhesive tape, and wire insulation.

Color Masterbatch Making Extruder

Color masterbatch compounding is one of the main application for twin screw extruder. Color MB is used for any polymer and all kinds of product.

Color Masterbatch Making Extruder

Due to their small particle size micro pellets spread much more uniform and distribute finer as the conventional raw polymer. In contrast, conventional master batches with “normal” sized pellets must be used in higher dosages to achieve the desired effect. Therefore, using micro pellets, less colorants are required, which lead to significant cost savings as master batches are extremely expensive compared to crude polymers, Master batches in shape of micro pellets are easier to handle, better to dose and dust free. Twin screw extruder is ideal for masterbatch manufacturing process.

Pet Food Extruder

It is a widespread and established technique in using pet food extrusion equipment in the pet supplies industry. There are some benefits of the production process below.

Pet Food Extruder

  1. Fast-speed. The pet food extruder can run consistently with high-quality products and strict production deadlines. Our extruders are designed for fast, easy changeover and cleaning between runs.
  2. Flexible. The pet food extruder is highly adaptable and suitable for a wide range of input materials. At the same time, the extruder can be extruded in various shapes, textures, and colors in different forms for final molding.
  3. Consistent. The pet food extruder and cutting produces can produce a very homogeneous end product with constant cross-section and dimensions.
  4. Efficient. The pet food extrusion process is cost-friendly, especially once conditions have been optimized. Precise process control and automation reduce raw material waste and increase production efficiency.

About Us

Kairong Group, headquartered in Nanjing, China, is a global manufacturing and trading company in the field of high-performance plastics and rubber processing equipment, extrusion solutions, masterbatch, and compounding, etc.

Its unit Nanjing Haisi Extrusion Company is a professional manufacturer of twin screw extruder, single screw extruder, two stage extruder,equipment for dryer and its related auxiaries.  We tailor solutions from raw materials, materials processing equipment, to injection for different customers. 

If you are looking for a reliable twin screw extruder manufacturer, then we are your worthy choice manufacturer, you can browse our homepage to learn more about our company and products, and if you have more questions You can contact us directly, we are happy to provide you with high-quality service and excellent products.



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