Twin Screw Extruder – The Ultimate FAQ Guide

The twin-screw extruder is a highly demanded manufacturing machine in today’s industrial world. To purchase this machine, you must look into the major concepts of this machine. Hence, we have discussed all the essential concepts regarding a twin-screw extruder in this guide below. By looking into this guide, you can better understand the twin-screw extruder before purchasing it.

1. What does a Twin-Screw Extruder Mean?

Figure1: Twin Screw Extruder

In simple terms, there are two types of twin screw extruders. These twin-screw extruders are known as machine’s that consists of two screws. The two types of these twin screw extruders include:

• Parallel Twin Screw Extruder
• Conical Twin Screw Extruder

Between both these types of twin screw extruders, the parallel twin screw extruder has two more types of twin screw extruder machines. It firstly includes the co-rotating twin screw extruder. This co-rotating twin screw extruder has co-penetrating and self-cleaning screws, and they are mounted on the shafts. Moreover, these screws rotate in the same direction inside fix closed housing. This fixed closed housing is called the barrel.

Apart from this, the other type of parallel twin screw extruder is the counter-rotating twin screw extruder. The difference in this machine from the previous one is that this machine has no shafts. Instead, it only has one while screw that is a part of the counter-rotating twin screw extruders design and working.

2. Where is the Twin-Screw Extruder Used?

Fig2: Usage of a Twin Screw Extruder

Using a twin-screw extruder is a rather easy process. It has been used for years to produce highly homogenous and finely structured products. With the different types of these twin-screw extruders, different items can be manufactured. Moreover, these twin-screw extruders come with a wide range of screw and barrel designs. Hence, using a twin-screw extruder can be easy and adjusted according to the various screw production and process functions requirements.

Mainly, the twin screw extruder is used in the processing of various energetic materials. Some such materials include:

• Gun/Rocket propellants
• Plastic bonded explosives
• Pyrotechnics
• Thermo-baric explosives, etc.

Apart from this, different types of twin-screw extruder types are used to manufacture different types of products. These products according to the twin-screw extruder types include:

• Co-Rotating Twin Screw Extruder:

It is used for compounding and PET pelleting line, PET sheet extrusion line.

• Counter-Rotating Twin Screw Extruder:

It is used for making sheet, products, and PVC pipes.

• Conical Twin Screw Extruder:

It is used for making PVC products and WPC products

With all these products being manufactured with different types of twin-screw extruder, you can surely call this machine highly flexible and suitable to be a part of the manufacturing world.

3. Who Invented the Twin-Screw Extruder?

Wilhelm Ellermann firstly invented a twin-screw extruder in the year 1940. Wilhelm Ellermann was of Krup, and he developed the first commercial intermission and counter-rotating twin-screw extruder. At that time, the first twin-screw extruder was named the Knetwolf.

Moreover, this Knetwolf (Twin-screw extruder was patented in 1941 by Krupp. Along with that, its first unit was also built in 1941 for I/G Farben. These first units had screws that were as long as 400 mm in diameter.

https://www.clextral.com/technologies-and-lines/technologies-et-procedes/twin-screw-extrusion-technology/

4. How is a Twin-Screw Extruder Machine Operation Different from Operating a Single Screw Extruder Machine?

Fig3: Twin Screw Extruder vs. Single Screw Extruder

Since a twin-screw extruder is quite similar to a single screw extruder, its operation can also relate. While different brands and companies manufacture different twin-screw extruders, their performance can also differ. Hence, some twin-screw extruders perform like the single screw extruders. Yet, most other twin-screw extruders can work differently.

5. What are the Different Sizes of the Twin-Screw Extruder?

Different types of twin-screw extruders are manufactured today by different brands. It also includes different sizes. Sizes of this machine fall around 25 to 244mm. Same is the diameter size of the twin-screw extruders barrel. Moreover, the barrel lengths of the twin-screw extruder and the diameter ratio can be around 39 to 48. The good thing about the twin-screw extruder is that its length can be altered according to its different usage requirements. In fact, even the parallel twin screw has the L/D altering option. Hence, you can use the twin-screw extruder according to the different length demands during the manufacturing process.

6. What are the Main Components in a Twin-Screw Extruder?

 Fig4: Components in a Twin-Screw Extruder

There are different components present in this machine. Some main components include:

• Screw barrel
• Gearbox
• Heater
• Electrical cabinet
• Motor, etc.

Each of these components present in this machine is its most important part. These work simultaneously for improving the performance of the twin-screw extruder overall.

7. What are the Types of Twin-Screw Extruders?

Fig5: Types of Twin-Screw Extruders

While the screws of a twin screw extruder are its major components, different types of twin screw extruders can have their screw placement in different ways. Some can have counter-rotating screw placement, while some come as co-rotating screws – depending upon the type of the twin screw extruder.

With each of these performance criteria, the twin-screw extruder can come in different types. Altogether, four major types of twin-screw extruders were introduced by Miller in 1990. These types include:

• Intermeshed – co-rotating
• Intermeshed – counter-rotating
• Non-intermeshed-co-rotating
• Non-intermeshed-counter-rotating

8. How Many Types of Extruders are There in Total?

The list of extruders, their types, and their models is comparatively huge. However, if we take about the basic types of extruders that are used in industries of food and snack manufacturing, there are mainly three types. These types include:

• Conical twin screw extruder
• Co-rotating parallel twin screw extruder
• Counter rotating parallel twin screw extruder

Even with all these types, the screw extruders are commonly used today.

https://www.youtube.com/watch?v=LCKo8js7RMM

9. What Makes Torque an Important Part of the Twin-Screw Extruder?

Fig6: Large Capacity Twin-Screw Extruder

Torque plays a huge role in the twin-screw extruder’s performance. Since this machine is used to manufacture different industry products, we can commonly find it in the manufacturing industries. Hence, this machine is highly demanded in large-scale production industries.

Now what makes a twin-screw extruder offer increased capacity in manufacturing finely structured products is its torque? When the twin-screw extruders torque is increased, the machine’s compounding speed increases. In this way, the twin-screw extruder can manufacture more products in a specific time.

10. Why is the Modular Construction of Twin-Screw Extruder In-Demand?

Fig7: Modular Construction of Twin-Screw Extruder

Modular construction is a different construction method of the twin-screw extruder. With the help of this construction, the twin-screw extruder is manufactured with efficient screw and barrel sections. We can use it for various purposes like:

• Pumping
• Mixing
• Venting
• And feeding

The good thing about modular construction twin-screw extruders is that we can use them for these purposes at any desired location. In fact, if we talk about the one set modular construction twin screw extruder, these extruders allow adjustment of the modular construction. As a result, it can accept various materials and formations allowing the production of different compounding materials – all with a one set modular construction twin screw extruder.

11. What Companies Manufacture Twin-Screw Extruders in China?

Since a twin-screw extruder is one highly popular and demanded extruder type today, it is manufactured in all the largest manufacturing countries. It can include manufacturing countries like the US, China, etc.

Yet, if we only talk about China-based companies that manufacture the twin-screw extruder, then it can be hard to find reliable manufacturers that offer all types of twin screw extruders in high-quality.

Yet, with our wide variety of machine’s that fall in the industry market, you can easily purchase the best quality and suitable type of twin screw extruder without any complications.

12. What is the Estimated Market Size of Twin-Screw Extruder Machines?

Fig8: Estimated Market Size of Twin-Screw Extruder

Since the twin-screw extruder has high demands as a manufacturing machine, its market demands are huge. If we talk about two major economic countries, then the market demand of this machine in the US and China today is:

• The US market-demand of twin-screw extruder is estimated up to %253.5 million in 2020.
• China’s market demand for this machine is estimated to reach a total of $200.4 million by 2027.

13. What is the Cost of a Twin-Screw Extruder?

Fig9: Large Twin-Screw Extruder Machine

The costs of a twin-screw extruder can vary a lot. From its type to its amount and quality you are looking for, each serves to increase or decrease the twin-screw extruders cost.

As an industry, if you plan to purchase a reliable and highly efficient twin-screw extruder, then it is better that you look for high-quality twin-screw extruders. Such machines may not come cheap if you choose a reliable company. However, investing a good amount in the twin-screw extruder means that you can benefit from its service for years to come.

Apart from looking into the twin screw extruder quality, it is also very important to evaluate what kind of twin screw extruder you need to purchase. According to the market demand and efficient performance, all the twin screw extruder types have different market-value today. In a list of high to low, all the types of twin screw extruder can be mentioned as:

• Modular twin screw extruder (having the highest price)
• Counter rotating and parallel twin screw extruder (costs lower than the modular type)
• Conical twin screw extruder (has the lowest cost in the market)

14. What is the Demand of a Twin-Screw Extruder Globally?

Fig10: Demand of a Twin-Screw Extruder

It is one of the most reliable machines in the industry market, making its market size being the op 12^th in the machine industry. It is one of the most efficient and reliable option for producing fine products for various needs. Some highly demanded products in various industries are manufactured using a twin-screw extruder.

However, if we talk about the twin-screw extruder’s overall market-demand, then its demand is estimated to rise. According to experts, the global market size of the twin screws extruder is certain to rise at a considerable rate anytime from 2021-2026.

15. What Products are Manufactured with a Twin-Screw Extruder?

Fig 11: Thermoplastic and nanofibers manufacturing

Usage of a twin-screw extruder is found in two different fields/areas. This includes:

• Polymers processing
• Processing special items.

Now the polymers can be difficult for processing in the twin-screw extruder. It’s mainly because these polymers don’t flow easily. Moreover, the polymers can degrade readily.

Other than that, the twin-screw extruder’s specialty processing operations include compounding, de-volatilization, and chemical reactions.

Apart from this basic manufacturing demand, the different types of twin screw extruders are also used in different production needs. It includes:

• Co-Rotating Twin Screw Extruder:

This type of twin screw extruder is used for the production, preparation, and processing of highly viscous materials.

• Counter- Rotating Twin Screw Extruder:

This type of twin screw extruder is used for the manufacturing of various plastic products and their processes.

• Conical Twin Screw Extruder:

This type of twin screw extruder is specially used to produce heat sensitive materials. These materials can include; PVC, Food, and Pharma items.

16. What Makes a Single Screw Extruder and a Twin-Screw Extruder Different?

Both the single and twin screw extruders are completely different in design and performance.

When it comes to the twin-screw extruder, as mentioned earlier, this type of screw extruders has two different types, i.e., parallel twin-screw extruder and conical twin-screw extruder.

However, the single screw extruder may be available with different types of accessories, but it doesn’t have specific types.

Apart from this, both the single and twin screw extruders have different performing criteria’s too.

Fig 12: Single vs Twin Screw Extruder

We can differentiate this as:

• Single Screw Extruder:

The making and performance of a single screw extruder make the granule materials in this extruder stay in there for a longer time.

This effect causes a slower production time when you are using the single screw extruder.

• Twin Screw Extruder:

On the other hand, the twin-screw extruder has a more complex operation irrespective of its types.

Additionally, all the types of twin-screw extruders also come different, and more (than the single screw extruder) requirements of controlling the extrusion process.

Hence, the twin-screw extruder serves as a more complex and advanced extruder machine to produce various products, making it top the simple controlling process of the single screw extruder.

https://www.youtube.com/watch?v=08_f5BRYcyM

17. How Many Screws does a Twin-Screw Extruder have Mounted on it?

Fig 13: Twin Screw Elements

As the name suggests, the twin-screw extruder has two screws mounted in the extruder’s barrel.

However, while both the twin-screw extruder types may have two screws in their design, they may be different in the overall look and performance.

In simpler terms, both the parallel and conical twin-screw extruders may have two intermeshing identical screws (except for the counter-rotating twin-screw extruder, which is a type of parallel-twin screw extruder).

These identical screws are designed in a way that they are cased in the extruder’s barrel.

What makes a difference among the parallel and conical twin-screw extruders with the presence of two screws is the screw and barrel type.

Depending on the name/type of the extruder, the screw and barrel in a twin-screw extruder can be either parallel or conical.

18. What Areas do We Use a Twin-Screw Extruder in? 

As mentioned earlier, the twin-screw extruder is used for the processing of plastic.

If we look into plastic’s manufacturing process, every single plastic undergoes the stage where it is processed on a twin-screw extruder.

For a clearer idea, the usage of a twin-screw extruder (of any type) helps to mix the materials present in plastic and then impart the plastic properties to the final part.

With that being said, since the twin-screw extruder is an important part of plastic manufacturing, it is used in the manufacturing of every plastic material present worldwide.

Hence, we can consider the twin-screw extruder to be a part of the different areas where plastic is commonly used. Some such areas include:

• Nutrition
• Health and well-being
• Shelter
• Safety and security
• Transportation
• Communication
• Sports
• Leisure activities

https://www.youtube.com/watch?v=2544pagWnsY

Apart from all these areas, we can also consider the usage of a twin-screw extruder for manufacturing various types of daily used products.

Some such products that we use in our day-to-day lives include:

• Carpet fibers
• Packaging films
• Windshields
• Car interiors
• High-tech products and gadgets (incl. space-shuttle parts, synthetic wine corks, conductive parts, etc.)

https://www.youtube.com/watch?v=Myys_MkyXMU&feature=emb_imp_woyt

 A twin-screw extruder takes part in manufacturing all the everyday use products that fall in these production areas.

19. Can you Predict the Performance of a Twin-Screw Extruder According to Its Flow of Materials?

Since a twin-screw extruder’s design and performance are very complex compared to a single screw extruder, it is hard to predict its parlance based on the geometrical features.

In other terms, the flow of material and the flow patterns of a twin-screw extruder are complex and difficult to predict.

Due to this reason, the simulation of processes isn’t developed properly in the same as it is in the single-screw extruders.

As a result, you can’t make accurate calculations according to the extruder’s geometrical features, processing conditions, and polymer properties.

However, the construction of a twin-screw extruder does allow the user to change the screw and barrel elements.

Hence, by changing the screw and barrels of the extruder’s modules, the appropriate operation can be performed without the need for any geometrical calculations.

20. What Should you Consider Before Purchasing a Twin-Screw Extruder?

Fig 14: Twin Screw Extruder

While there can be different manufacturers and suppliers of a twin-screw extruder, it is better to look for the right option.

One major thing to consider during this process is to understand what type of twin-screw extruder you need to purchase.

Once you choose the correct according to your production needs, i.e., co-rotating or counter-rotating, you can look for other important aspects.

These aspects include:

• Quality manufacturing of the twin-screw extruder and its components
• Reasonable price of the twin-screw extruder
• Availability and durability of the extruder’s parts
• Overall performance or service of the twin-screw extruder in terms of efficiency

Once you consider these aspects before buying the right type of twin-screw extruder, you can purchase a cost-efficient extruder that can offer you a lasting service.

21. What are the Applications of a Twin-Screw Extruder?

A twin-screw extruder involves the continuous process of extrusion during the manufacturing of any product.

With this performance, a twin-screw extruder has the ability to manage intensive mixing and the high-pressure extrusion during the process.

Using such a high and powerful extrusion performance can help in processing various materials, including:

• Gun and rocket propellants
• Plastic bonded explosives
• Pyrotechnics
• Thermo-baric explosives, etc.

This is only a specific production ability of a commonly used powerful twin-screw extruder.

However, the different types of twin-screw extruders can also be useful for manufacturing products having different applications (some are mentioned above).

22. What Advantages and Disadvantages Come with the Usage of a Twin-Screw Extruder?

Fig 15: Advantages of Twin Screw Extruder

Since the twin-screw extruder is a powerful and complex extrusion machine, it comes with plenty of advantages as well as disadvantages.

These advantages and disadvantages can be common among all types of twin-screw extruders.

They include:

The Advantages: 

• Efficient mixing
• Better and less dependent pumping efficiency
• Fast and uniform heat exchange rate from the barrel surface to the material
• Has a uniformly distributed residence time
• It consists of a flexible modular configuration that makes it a more versatile machine.
• Handles high moisture and sticky materials easily
• Allows self-wiping while reducing the residue buildup risks
• Doesn’t have any serious feeding problems with the cohesive materials

The Disadvantages:

• Demands a higher capital expenditure and operation cost
• The twin-screw extruders have a more complex and less robust mechanical design.
• It can be very sensitive to various mechanical abuse situations like high torque, etc.

23. What is Twin Screw Compounding Extruder?

Fig 16: Twin Screw Compounding Extruder

While the performance of almost all kinds of twin-screw extruders may be similar to some extent, a twin-screw compounding extruder is different.

This type of twin-screw extruder is known to be a versatile twin-screw extruder.

Moreover, such versatile twin-screw extruders are not just used for compounding but also in reactive extrusion and devolatilization.

Such types of twin-screw compounding extruders mainly focus on manufacturing products that can fall into categories of:

• Pellets
• Fibers
• Tubes
• Sheets
• The film, etc.

Another specification of the twin-screw compounding extruder is that all these extruders are starved-fed.

This specification of being a starve-fed device makes a twin-screw compounding extruder different from the common types of twin-screw extruders (i.e., parallel and conical, etc.).

Hence, it also means that the twin-screw compounding extruder isn’t as commonly used in the production industry as the other common twin screw extruder types are trusted and used.

These are all the basic and important queries regarding the twin-screw extruder.

If you have any more queries regarding the usage, performance, reliability, and supplier of a twin-screw extruder, you can get in touch with us.