Twin Screw Extruders

If we ask what is a twin screw extruder machine rotating in the same direction, the best answer is the perfect blend. The only machine that can melt the formulated materials at high temperature and pressure, mix them in the most perfect way and produce materials with homogeneous distribution and dispersion with new properties is the twin screw extruder machine.
Twin screw extruder screws have a self-cleaning modular screw structure. Screw elements with various geometric shapes are the main factor that forms the process. Modular screw and barrel arrangements are made in various variations according to the product to be produced. 

In twin screw extrusion machines, production can be made in machines working in many different sectors from plastics to food, from cosmetics to pharmaceutical industry.

In general, compound materials, which find a place in the production of almost every plastic-based products, are basically produced by processing raw materials under special formulations at high temperature and pressure. Monomex twin screw compounder machines are used to improve the properties of materials.
The expert who will select the extruder chooses according to the type of plastic material to be processed. Various variables such as auger geometric features, feeding type are determined according to the type of plastic material. The most important point to be considered is to make the right design according to the material to be produced, not according to the screw diameter of the extruder.

Applications of Twin Screw Extruders in Industry

Plastic Extrusion: Twin screw extruders are widely used in the plastic extrusion process. In this process, plastic granules or powders are melted and passed through an extrusion mould and plastic products of the desired shape and size are obtained. Twin screw extruders are the preferred equipment in plastic extrusion due to their high production capacity and better mixing properties. They are used in the production of various plastic products such as pipe, profile, film, sheet, wire and cable coatings.

Polymer Blends: Twin screw extruders are used in the production of polymer blends. Twin screw extruders are ideal when different polymer types or polymers and fillers need to be mixed. The rotation of the two screws against each other ensures better mixing of the materials and a homogenous mixture is obtained.

Resin Modification: Twin screw extruders are used in resin modification processes. Additives, colourants, stabilisers or other chemical substances are added to polymer resins to change the properties of the polymer. Twin screw extruders are ideal for homogeneous mixing and dispersion of materials.

Recycling Twin screw extruders are widely used in plastic recycling processes. Recyclable plastic materials are melted and shaped by twin-screw extruders and reusable plastic granules or products are obtained. This promotes the reuse of plastic waste and contributes to sustainable plastic production.

Food Processing: Twin screw extruders are also used in the food processing industry. In particular, they are widely used in the production of starch-based products. Starch is mixed with water and other ingredients and fed into twin-screw extruders and starch-based products are produced through processes such as cooking, gelatinization, extrusion and drying.

This is just an example of some industrial application areas of twin screw extruders. In reality, the application areas where twin screw extruders are used are quite diverse and they have a wide range of applications, especially in the plastics processing industry.

Choosing the Right Twin Screw Extruder for Your Needs

To select the right twin screw extruder, it is important to consider the following factors:

Process Requirements: First, you must determine the specific requirements of your manufacturing process. Which materials will you process? What products do you plan to produce? What production capacity do you need? Answering these questions is a fundamental step for choosing the right twin screw extruder.

Material and Properties: You should evaluate the properties of the materials you will process. Viscosity, flow properties, thermal behaviour and other material characteristics must be compatible with the design and specifications of the twin-screw extruder. Material compatibility is critical for quality production and desired product properties.

Extruder Design: The design of twin-screw extruders is an important factor affecting their performance. Factors such as the diameter, length, number of steps and profile design of the screws affect the process of mixing, melting and advancing the materials. You should also consider other design features such as thermal control systems, feeding mechanisms and accessories.

Quality and Reliability: Choosing a quality twin-screw extruder ensures long-term efficiency and reliability. Choosing a reliable manufacturer or supplier ensures you get a solid product and good customer support. Checking references is important to verify that the manufacturer adheres to quality standards and cares about customer satisfaction.

Cost and Budget: Prices for twin-screw extruders can vary by design, features and manufacturer. Considering your budget and cost expectations, you should choose the option that best suits your needs. However, instead of automatically choosing the cheapest option, it is important to evaluate other factors; quality, performance, lifetime, energy consumption and long-term cost advantages, the most important of which is the product capacity to be produced per hour.

In conclusion, to choose the right twin screw extruder, it is important to consider your process requirements, material properties, design factors, quality and reliability standards and your budget. By analysing these factors, you can determine which twin-screw extruder best suits your needs.

Features of Twin Screw Extruders

Twin Screw Design: Twin screw extruders have two screws, as opposed to a single screw extruder. This means higher production capacity and better mixing properties. With two screws rotating in the same direction with each other, the materials are better homogenised and a better melting is achieved.

High Throughput: Twin screw extruders are capable of processing higher quantities of plastic material. The two screws working together allows the material to melt quickly and allows for higher production speeds.

Multipurpose Use: Twin screw extruders are generally capable of processing a wide range of materials. They are suitable for processing polymer materials with different viscosity and properties. This provides flexibility in the production of various plastic products.

Better Mixing: The rotation of the two screws against each other allows for better mixing of materials. This helps to achieve a homogenous material distribution within the extruder system and products with better physical properties.

Better Control: Twin screw extruders provide a better control during the process. The ability to independently adjust parameters such as rotational speed and temperature in the screws allows more precise control of the material processing process.

Longer Life: Twin screw extruders are more durable than single screw extruders. The two screws distribute the shared load, resulting in less wear and a longer service life.

Benefits of Using Twin Screw Extruder

Wider Range of Materials: Twin screw extruders can be suitable for a wider range of materials than single screw extruders. They can be a more suitable option for processing materials of different viscosities.

Better Thermal Control: Twin screw extruders generally provide better thermal control. This can help to more evenly manage the temperature of the material being processed and reduce unwanted thermal distortions.

Less Energy Consumption: In some cases, twin-screw extruders can consume less energy compared to their single-screw alternatives. They can reduce energy costs by providing a more efficient process.

Better Pressure Control: Twin-screw extruders can provide better pressure control. This can help achieve more consistent products by preventing unwanted deformation of the material.

Better Mixing: Twin-screw extruders provide more homogeneous mixing of materials. The two screws rotate in the same direction with each other, helping to achieve a homogeneous material distribution and products with better physical properties. This ensures that products have more consistent properties.

Better Thermal Control: Twin screw extruders provide better thermal control during material processing. The fact that each screw can be heated individually and temperature profiles can be set independently allows for more precise control of the material processing process. This results in better achievement of the desired product quality and properties.

Better Transfer and Feeding: Twin screw extruders provide better transfer and feeding of the material. The two screws rotate in the same direction with each other, allowing the material to move forward more efficiently. This provides a smoother and more stable flow in the material feeding process.

Wide Application Area: Twin screw extruders are capable of processing a wide range of materials. It provides flexibility for processing materials with different viscosity and properties. This provides diversity in various industries and in the production of plastic products.

Frequently Asked Questions About Twin Screw Extruders

1. What are twin screw extruders?

A twin-screw extruder is a machine in which plastic materials are melted and shaped. Two screws rotate in a funnel through which the material is fed and melt the material, mix it and pass it through the extrusion mould to obtain a plastic product of the desired shape and size.

2. How to maintain twin screw extruders?

Regular maintenance of twin screw extruders is important. Maintenance includes cleaning the screws, lubrication, checking the heating and cooling systems, mould cleaning and general machine cleaning. Regular maintenance should be carried out in accordance with the instructions provided by the manufacturer and any wear or damage should be repaired as necessary.

3. How can the energy efficiency of twin-screw extruders be improved?

The following measures can be taken to improve the energy efficiency of twin-screw extruders:

- Heating and cooling systems should be checked for energy efficiency and necessary improvements should be made.

- Correct lubrication should be used to reduce friction loss in the screws and worn or damaged parts should be replaced to avoid unnecessary friction.

- Correct proportioning and control of the material feed must be ensured, thus avoiding unnecessary energy consumption.

- Energy efficient motors and control systems should be used.

The above questions cover general information about twin screw extruders. If you have more specific questions, please contact the R&D department.

4. Which materials can be processed with twin-screw extruders?

Twin screw extruders are capable of processing a wide range of materials. Below are some examples of common types of materials that can be processed with twin screw extruders:

Thermoplastics: Polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), polystyrene (PS), polymethylmethacrylate (PMMA), polyamide (PA), polycarbonate (PC), polyethyleneterephthalate (PET), polybutadiene (PB), polyurethane (PU), etc.

Thermoelastomers: Thermoplastic elastomers (TPE), thermoelastomeric urethanes (TPU), styrenic block copolymers (SBC), ethylene-vinyl acetate (EVA), etc.

Resins and Composites: Epoxy resins, polyester resins, acrylic resins, carbon fibre, glass fibre, wood powder, fillers (talc, calcium carbonate, glass microbeads, etc.), etc.

Food Processing: Wheat flour, corn starch, rice flour, soya protein, whey powder, sugar, chocolate, etc.

Recycled Materials: Recycled plastics (e.g. recycled PE, PP, PET), recycled rubber, etc.

These are just some examples of materials that twin screw extruders can process. The materials that can actually be processed may vary depending on machine design, geometry of the screws and other factors. As the characteristics and processing requirements of each material are different, please contact our expert staff to verify the suitability of a twin screw extruder for a specific material.

5. How to optimise the output of a twin-screw extruder?

To optimise the output of a twin-screw extruder, you can consider the following factors:

1. Screw Design: Screw geometry and configuration affect the flow and mixing of the material. Factors such as screw profile, screw clearance ratio, screw diameter and pitch can affect the homogeneity and flow characteristics of the material. Screw design should be optimised in accordance with the characteristics of the material to be processed and product requirements.

2. Feeding and Dosing: Correct feeding and dosing of the material ensures efficient operation of the twin-screw extruder. The material feeding system must be able to control the feed rate and ratio and regulate the material flow. The dosing system ensures that additives and fillers are added in the correct proportions.

3. Temperature Control: It is important to melt and hold the material at the correct temperature. Temperature control should be carried out in different zones (feeding zone, melting zone, cooling zone, etc.) in the twin screw extruder. The optimum temperature profile improves the output quality by influencing the melting process, viscosity and flow properties of the material.

4. Cooling and Moulding: The molten material coming out of the twin-screw extruder passes through cooling systems and moulding mechanisms and takes the desired shape. Cooling systems must ensure rapid and controlled cooling of the material. The moulding system ensures that the product is formed in the correct size and shape. The cooling and moulding processes have a major impact on output quality and production speed.

5. Machine Settings and Controls: Further settings and controls on the twin screw extruder are important to optimise output. Parameters such as feeding speed, rotation speed of the screws, pressure control, vacuum setting, etc. must be set correctly. Automation and control systems can be used to monitor the process, analyse data and make adjustments as necessary.

The above factors are some basic points to consider to optimise the output of a twin screw extruder. However, the optimisation requirements for each application and material may be different. It is important to get more specific guidelines and recommendations by contacting our company experts.

6. What is a co-rotating twin-screw extruder?

A co-rotating twin-screw extruder is a special type of twin-screw extruder. In this system, a configuration is used in which both screws rotate in the same direction. That is, both screws rotate clockwise.

Twin screw extruders rotating together in the same direction are generally used for melting, mixing and moulding polymers. In this system, the fact that the screws rotate in the same direction allows the material to progress better and a more homogeneous mixture is obtained. Screws rotating in the same direction push the material in a better way, providing better fluidity and feeding.

This type of extruder is effective in processing high viscosity materials and mixing complex formulations. The rotation of the screws in the same direction helps to reduce temperature and viscosity differences within the material, resulting in a more homogeneous product. Furthermore, twin-screw extruders that rotate together in the same direction can enable higher production speeds and lower energy consumption.

7. What is the twin screw method?

The twin-screw method is an extrusion method for melting, mixing and moulding polymers. In this method, a twin-screw extruder is used.

The twin-screw method provides better mixing and processing efficiency compared to a single screw. The two screws in the extruder are placed parallel to each other and rotate simultaneously. The rotation directions of the screws are usually opposite to each other. This ensures a better mixing of the material and a homogeneous melting.