Blog

spc floor extrusion line

Plastic Sheet Extrusion Line: Types Of Extruders

Content Directory

Introduction

The plastic sheet extrusion line comes with many different equipment and accessories. They include; Molding machine, Auto-cutter machine, Feed Hopper, Vacuum calibration tank, Haul-off machine, Extruder, Extrusion die tank, and so on. On top of that, other minor accessories all work alongside the main machine to fulfill the desired goal. Plastic extruders form up the essential and core components that need to be up and run at all times in an extrusion production line. Therefore, a plastic Extruder has a significant and massive impact on the final product.

Choosing the Ideal Extruder For the Plastic Sheet Extrusion Line

One tip to having a prosperous plastic sheet extrusion line begins with securing the right and best machines and accessories. Picking a suitable extruder for your plastic sheet extrusion line can be a complex affair. First, one has to pick a reliable and trusted manufacturer and supplier.

That is not enough; the manufacturer needs a clean reputation and record with good customer ratings and reviews. On top of that, you need to ensure that the manufacturer also makes quality and reliable machines. All that in one plate makes it a burden to a first-time or starter. Fanlyplas has all that under its umbrella.

This article will dig deeper into the different types of Plastic Extruders specifically. We will also know more about the pros and cons of each extruder and possibly the best you can apply during the plastic sheet extrusion process.

What Are The Different Types Of Extruders?

Plastic Extruders come in these three main types. We have the single-screw extruder, ram extruder, and the twin-screw Extruder. However, most extrusion production lines come with single-screw extruders. A vast number of extruders come that way.

It does not mean that the twin-screw extruders are not standard on the market. They are as well available in huge numbers. They come in two types as well. We’ve got the twin-screw extruder that does the rigid PVC extrusion and the compounding twin-screw extruder.

Some other types of extruders are beyond the twin-screw ones. More than three screws can all fit at a go inside the Barrel.

Ram Extruder

It is one of the simplest extruders. Its working principles and mechanisms are fundamental and not as complex as other extruders. It works by feeding the material into a cone-shaped barrel/feed hopper. . A piston fitted on top of the RAM works by applying pressure on the material. The stress and thermal heat from the Barrel act on the material until it perfectly decomposed.

The RAM extruder comes in two types. We have the Horizontal Ram extruder and the Vertical Ram Extruder. Despite the positioning difference, the working system and principles are all the same.

Advantages of a ram extruder

  • The RAM extruder is easy to use- To begin with; the set-up procedure is very straightforward. It does not need more skills and experience while working.
  • RAM Extruder is user-friendly and has very few maintenance issues. Working on a RAM extruder is among the best experiences one can ever imagine. The simplicity of the machine makes workflow more manageable and more fun. Staying long without faults does make the machine immune to breakdowns.
  • The design of this Extruder, which is horizontal, offers enough room to store and keep other materials. The small extruder size saves so much space and makes the machine’s working area huge.
  • Another advantage of using this type of machine is the quick-setup process. Unlike other extruders, the RAM extruder is easy to set up and fix. That not being enough; the die head replacement process is rapid and easy. The flexibility of this Extruder will surely amaze you.
  • Automated feeding. You do not have to involve human labor in lifting and pouring resin bags into the Feed Hopper.

Disadvantages of a ram extruder

  • Plastic extrusion using a RAM extruder is a discontinuous process.
  • Wastes a lot of time spent on heating the resin.

Single Screw Extruder

Just from the name, it is clear that this type of Extruder comes only with one screw in the Barrel. The single screw is responsible for pushing the material/resin through the Barrel up to the end of the Die. In this type of Extruder, the screw plays a vital role compared to the “heart” of the Extruder.

Transmission system of a single-screw extruder

A single-screw extruder is responsible for powering the Extruder and propelling the screw in the transmission system. The transmission system determines and controls the speed at which the screw will rotate. The transmission ensures the speed of the screw is stable and uniform in whichever type of resin under extrusion and works in any given torque, pressure, and heat.

Motor

The motor is the primary source of power for the process. Works by converting electrical energy into motion that can rotate gears that make the screw turn. The motor’s speed setting relies on the type of material under extrusion. The average rate of most motors is usually around 10-100rpm.

Reducer

A reducer reduces the speed of the screw and increases torque where necessary. For example, the reducer moves the V-Belt to gear with small teeth during high-speed times, reducing speed.

The performance and speed of the screw in a single-screw extruder determine a lot in an extrusion process: the melt temperature, dispersion of additives, plasticization activities, power consumption, and productivity in general.

Advantages of a single-screw extruder

  • Cheap to purchase- Unlike its counterpart, the Twin/multiple extruders are cheap on the market. You do not have to spend so much on hard-earned money while shopping for a single-screw extruder.
  • A complex transmission– A single-screw extruder comes with an involute transmission system. That ensures a seamless and stable power supply to the screw. The screw can work smoothly and also produces less noise during the process. The involute transmission system can also bear large volumes of resin at once the screw works without struggling or weakling.
  • Superior performance– The power of the transmission system and the stable and steady screw sum up and make the Extruder mighty. You will, of course, notice an increased and better plasticization and high speeds of extrusion.
  • Advanced technology– The Single-screw Extruder has an incredible technological advancement ahead of old-school extruders. We are talking about digitized and automated monitoring systems, more parameters, and those that work perfectly well during an extrusion process.
  • Low energy usage- Power is a limited resource. Due to the increased power costs, folks are now shifting their focus toward power-saving machinery. Well, the single-screw Extruder falls under that category as well.
  • Long-life– No one wished for machinery that has a short life span. The single-screw Extruder beats other extruders hands-down when it comes to that. Not only will you run your Extruder for long, but you will also be in good shape and form if you are willing to look after the machine with extra care and maintenance.

Disadvantages of single-screw extruder

  • Overreliance on friction- A single-screw extruder applies friction as a critical factor that enables the movement of the material through the Extruder. Too much friction inside the Barrel and on the screw slows down the process. Overheating-related issues begin to pop in due to too much friction. Friction poses a massive threat to the well-being of the extrudate and affects the end product’s quality.
  • Pressures build up a lot- When using a single-screw extruder, you may come across an issue with too much pressure forming in the head section. Pressure affects the production line as counter-flow begin and the feeding speed decreases; hence workflow alongside productivity drops.
  • High shear rate- The high shear rate in a single-screw extruder is usually a result of the increased friction inside the Barrel. It causes too much heat to build inside the Barrel, affecting the entire material’s rate.
  • Small conveying capacity- A single-screw extruder has a small conveying power. It makes it unable to move large masses of material at once inside the Barrel.
  • Inferior performance– Among the commonly noted problems the Extruder cannot execute are; Polymer coloring and thermosetting powder processing.
  • Additives limitation- When using a single-screw extruder, you might not be able to add some special additives such as powder, paste, and glass fillers.

Twin-Screw Extruder

The twin-screw Extruder is another type of Extruder that works well for extrusion. One of the best extruders works best when extruding two different materials together. You want to consider extruding reactive polymer materials using the twin-screw Extruder since it works magic. Also, when you want to produce PVC products that are rigid and blended with wood fiber, extruders perfectly fit the job.

Two screws rotate alongside each other, either parallel positioned or on opposite sides. You can achieve either a corotating effect or counterrotating features and at the same time get an intermeshing effect or non-intermeshing one as well. It depends on the kind of material under extrusion and the desired output at the end of the production line. A twin-screw extruder works perfectly and smoothly under large volumes of resin. The results are notable with quality features. That makes it one of the selling points of such kind of Extruder. Here Fanlyplas, you can get one of this kind.

Advantages

  • High efficiency is one fact that all sorts of twin-screw extruders have. The twin screws offer immense mixing and conveying abilities that, in turn, fasten the extrusion speed and increase output number and improve production flow.
  • Unlike a single-screw extruder, a twin-screw extruder can handle materials with unique characteristics. A twin-screw extruder processes with ease sticky or gummy materials. Other types of extruders struggle in such events during extrusion.
  • Superior performance- A twin-screw extruder works incredibly well compared to other types of extruders. Super-fast processing speeds and quality end products are some notable features that make this type of Extruder top-notch.
  • Long-life- A twin-screw extruder has a long life span compared. One factor contributing to that is the self-cleaning feature of the Extruder’s Barrel. Accumulated waste materials that stay for long in the Barrel cause other related problems to the machine. However, the machine can clean itself and get rid of stuck waste products. At the same time, you also have to often clean the machine by yourself. Extra care maintenance is also a plus.

Disadvantages of a twin-screw extruder

  • Too much noise- The two rotating screws inside the Barrel contribute a lot to the noise produced by the machine. Noise is one factor that affects those around machines. Too much noise while working around the machine might not be safe and friendly to the workforce.
  • Expensive to purchase and maintain- A twin-screw extruder requires a considerable amount of cash to initially secure in the first place. It might not go well for guys who have a lesser budget. Once purchased, also brace yourself for high maintenance and operation costs.

What Are The Roles Of An Extruder In The Plastic Sheet Extrusion Line?

A Plastic extruder is arguably the main operation center during an extrusion process. Numerous vital activities occur under the plastic extruders due to the number of actions inside an Extruder. Otherwise, many fluctuations do take place in an Extruder. Below is a guideline on the activities that happen inside the plastic sheet production line extruder;

Plastic extruders comprise various parts that are linked together and work together to achieve the desired result. These parts play an individual role and are critical to the Extruder’s functionality. They are as follows;

Parts That Form a Plastic Extruder

  • A Hopper cylinder– It is a cylinder with a top conical shape where the resin/ thermoplastic material gets fed. Under this section, the first stages of an extrusion process begin. Comes with chrome-plated steel or nitrite alloy and has cooling water running through the jacketed steel casing. The conical design of a Feed Hopper increases sufficient feeding into the extruders. Special undercuts on the walls increase and promote more and faster resin input.

Note: The positioning of the feed hopper onto the Barrel affects entirely the type of resin fed into the Extruder. The molten resin flow rate needs close monitoring and regulation as well. Talking of; the flow of the molten resin, cross-sectional die space, and the speed of the screw in the Barrel.

  • Screw- This is a long rotating screw-like metal located inside the Barrel. It comes with shaped flights and pitches that enable the extrudate flow through the Barrel. The barrel screw comes in different diameters(D) and lengths (L) that differ with varying types of Extruders. The flights and pitches on specialized screws only apply to the specific resin type.
  • Barrel- A hollow cylindrical-shaped tubing that houses different sections. Each section has a role to play. These sections are as follows;

Parts Inside The Barrel

  • Feeding section- This section is located just beneath the feeder and is the first section in which the resin lands after being fed into the Extruder. The feeding section allows the pushing of the material through the Barrel into the compression section. As the material gets pushed, heat and pressure generated by the Barrel begin to melt down the resin. The large flight and pitches at the start of the barrel screw enhance more conveyance of the material.
  • Compression section- At this stage, the flights and pitches of the barrel screw begin reducing, and the material gets now melted. It is also at this section that reagents and additives can get mixed into the material. The material is now wholly molten at the end of this section and portrays a dough-like feel.
  • Metering section- This is the final section of the Barrel. It is under this section that the material now gets fully cooked. It then exits the Barrel.
  • Heaters and coolers- Temperature is a vital factor that affects the end product’s look and quality. Heating and cooling accessories linked to the Extruder monitor and regulate temperature.
  • Die- This is a cross-sectional area located on the end of the Extruder Barrel. It is responsible for the shape of the extrudate. The Die works by preventing the clogging of the molten resin. It also depressurizes the material.

Extrusion Process

It is inside an extruder that the extrusion process gets done the most. That includes feeding the material/resin, melting, compressing, cooking, shaping, and cooling. Below is a clear explanation;

Initial stage

When the material gets injected into the feeder, it gradually drops down into the Barrel. The Barrel is located proportionally below the feeder. The resin comes in contact with the rotating screw inside the Barrel. The rotation speed must correspond to the desired speed of the feeding rate. The screw pushes the material deep into the Barrel for further processing. At the beginning of the Barrel, there are several PID heating zones strategically positioned to ensure that the heating is uniform to avoid overheating the material.

Final stage

Further through the Barrel, the material passes through the three clearly explained sections. The material, now fully molten, passes through the breaker plate. This component clears out any contaminants in the material. The molten material then flows to the die head, which gets shaped into the desired forms. The Die must be well-designed to ensure the material flows through the cylindrical Barrel properly. A consistent flow of the material out of the Die will also ensure quality shaping. Uneven flow causes flaws that could be the possible causes of warping on the extruded plastic sheets.

FAQs about Extruders in Plastic Sheet Extrusion Line

How do you handle problems in an extruder?

No kind of Extruder is made immune to breakdowns and faults. After using the machine for a while, one will likely come across one or two problems. It depends on the manner and nature of the issue. If the issue isn’t complex, you can fix it by yourself. Let’s say worn-out parts or lost bolts. However, if the issue looks too complex, call for an expert to get it done. Here at Fanlyplas, we ensure that all our extruders come out perfect, needing less maintenance. You are guaranteed extended life with fewer issues. Remember, you also have to play your part, which is looking after the machine.

What kind of plastic materials gets fed into an extruder?

Many plastic materials can be fed into an extruder to produce a given product. Also, these materials can be mixed and blended to form a new product. They include;

  • The usual Polyvinyl Chloride(PVC)
  • Polypropylene.
  • High-density Polypropylene (HDP)
  • Low-density Polypropylene (LDP)

Conclusion

Are you looking to purchase a Plastic sheet extrusion machine? Worry no more; we’ve got you covered. We deal in manufacturing and supplying Plastic extrusion lines. Not only do we manufacture, but we ensure our products are quality and meet the customer’s needs and standards. On top of that, we make custom-designed extruders. Quality and reliability are key factors that get infused into our production spirit. Both Twin-screw and single-screw extruders are great types of machinery for Plastic extrusion. However, a twin-screw extruder carries the day for a more superior and quality performance. Either way, they are parts of a solid plastic sheet extrusion line you MUST have for a successful production. FANLYPLAS makes it possible.

Contact Now

Get free technical solutions and quotes
FANLYPLAS

Ask For A Quick Quote

We will contact you within 1 working day, please pay attention to the email with the suffix “@fanlyplas.com”