Extrusion Machine

Extrusion Machines – The Ultimate FAQ Guide

The demand for plastic products is increasing with every passing day.

Consequently, the market for extrusion machines is also expanding.

Here is a complete guide for Extrusion machines.

You can read the frequently asked questions about Extrusion Machine to know more about them.

The FAQ guide will help you make a better decision while buying extrusion machines.

Q 1) What are the Extrusion Machines?

Extrusion machines work by changing the size and shape of the provided material by forming the finished product of the desired shape and measurements.

The size and shape of the final product are controlled by a die attached to the machine.

The material is fed into the extrusion machine, where it passes through the die and comes out in a different shape.

Extrusion machines help in the process of creating an object from a solid body.

In this process, raw material goes through an extrusion machine to create the desired shape from plastics or metals.

   

Figure 1: Overview of extrusion machine

Q 2) How Does the Extrusion Machines Work?

Extrusion machines contain different components for feeding in the material, melting the material, shaping the material, etc.

Initially, the material, say solid plastic pellets, is fed into the machine which is followed by melting the plastic using a controlled heating system.

The melting zone in the extrusion machine contains a long screw-like structure in the barrel that helps move the material forward and also generates mechanical heat.

Then the molten product is pushed to the die section, which moulds the plastics into the desired shape.

The product is then cooled in a vacuum tank containing water to solidify it.

Q 3) How many Types of Extrusion Machines are there in Market?

Extrusion machines are available in numerous types in the market.

Different machines are used for shaping different types of materials e.g., plastic, metal, Rubber etc.

Extrusion technology defines that technically there are two types of extrusion machines, based on working temperature, available in the market.

One that serves the process for hot extrusion machines where the raw material is preheated before the process starts which forms rubber, metals, plastics, and other types of composite products that are formed by raw material.

Whereas cold extrusion machines do not require the product to be preheated or to be formed by any raw material.

Figure 2: Cold extrusion machineFigure 3: Hot extrusion machine

Extruding machines can also be categorized into single screw extruders and twin-screw extruders.

Based on twin-screw, the extruder machines are of two types: co-rotating screw extruder and counter-rotating screw extruder.

Co-rotating screws both rotate either in a clockwise or anticlockwise direction whereas in a counter-rotating screw extruder, one screw rotates clockwise and the other screw anticlockwise.

Q 4) Do Extrusion Machines Work for Plastics or Metals as well?

Yes, extrusion machine works for both metals and plastics which includes different types of metals as well, to form any extruded product.

Extrusion machines can help in the process of plastic extrusion as well as metal extrusion.

https://youtu.be/Y75IQksBb0M

Q 5) Which kind of Plastic is used in Extrusion Machines?

Different types of plastic materials are used for the formation of different products through extrusion machines.

Polyvinyl Chloride (PVC), high-density polyethylene (HDPE), polypropylene random copolymer (PPR), and polyethylene of raised temperature resistance (PERT) are used for the extrusion of plastic pipes.

Polyvinyl Chloride is also used for the formation of marble sheets, foam boards, and wall panels.

Apart from these, polyethylene, nylon, polypropylene, polystyrene, and acrylonitrile butadiene styrene are also used in plastic extrusion machines.

Figure 4: Plastic extrusions made by using different types of plastics

Q 6) What is the Difference between Direct and Indirect Extrusion Process?

Two approaches to extrusion that are used in extrusion machines are the direct and indirect process.

The difference in the two processes lies in the direction of the extrusion product and forces applied.

The direct extrusion process also called forward extrusion, occurs when the material flows in the same direction as the movement of the ram.

The material then passes through the die to form the final product.

Hollow and semi-hollow products such as pipes can be made by this method.

This method is widely used to form products with uniform cross-sections across the length.

A drawback is that in this approach high pressure has to be applied as the friction is very high, lubricants can also be used.

Figure 5: Direct extrusion process

 The indirect extrusion process is also known as the backward extrusion process.

As the name suggests this process works backward i.e., the material moves in the direction opposite to the direction of ram.

In this type, the die is present on the ram and thus the extrusion comes out of it.

This process has less friction, which makes extrusion faster with less heat generation and low energy consumption.

Figure 6: Indirect extrusion process

Q 7) What is the plastic extruder line?

The plastic extruder line is the application of extrusion machines but only for plastic products, including both the extruder and downstream apparatus.

The plastic extruder line machines involve plastic extruder and downstream machines depending on the required product.

These plastic extrusion lines are separate lines for moulding plastic into different shapes and sizes.

Figure 7: Profile extrusion line

For example, one of the lines can be for extrusion of plastic pipes and other can be for plastic sheets.

There are various plastic extrusion lines at Wecoex Machine that supply to plastic extrusion companies around the globe.

The plastic lines include pipe extrusion line, profile extrusion line, sheet extrusion line, foam board extrusion line and plastic recycle pelletizing line.

Q 8) What is the preferable method used for extrusion of plastic pipes?

The preferable method for extrusion of plastic pipes depends on the type of pipes required, mostly hot extrusion is used.

In this method, the plastic first moves down the hopper and is melted. This is essential to mould the material into the desired shape.

The plastic passes through the die and afterwards the product is cooled for solidification.

https://www.youtube.com/watch?v=YXGgs9JVw9o

A line of plastic pipe extrusion machines is available that use different methods depending on the demands of users.

Some use single screw methods while others use a double screw. Apart from this, the types of pipe extrusion machines are specific for the type of plastic used e.g., HDPE, PP etc.

Q 9) Why are PVC Pipes usually made from extrusion machines?

PVC pipes are known for their strength, durability and lightweight structure, for maintaining the quality extrusion machines are the best choice.

https://www.youtube.com/watch?v=3tLnA5cT_5k

The extrusion process is preferred over the welding process because it yields high strength plastic pipes that are less prone to damage.

Another benefit of using the extrusion machines for plastic pipes is pipes of various lengths, diameters, and thicknesses can be easily made.

Figure 8: Instruments used in PVC pipe extrusion.

 There are two types of PVC pipes in market: soft PVC pipes and rigid PVC pipes.

The soft PVC pipes are made by single screw extrusion machine and are mostly used as garden pipes.

Whereas, rigid PVC pipes are used as water pipes, drainage pipes, rain water pipes etc.

PVC pipes are made by feeding plastic pellets or powder into the twin-screw extruder or single screw extruder, heat melting them, and then extruding through the die.

The PVC pipes can then be cut into desirable length.

Q 10) What are the pros and cons of extrusion machines?

There are several advantages of using extrusion machines such as:

1. The extrusion process is capable of forming products of very simple to very complex cross-sections thus, the process provides flexibility.
2. The product’s surface is well finished when the extrusion machine is used.
3. The extrusion process is low cost, simple to use, fast and efficient with minimum waste.
4. Materials can be recycled if you are using an extrusion machine. The waste plastic of one industry can be used as a raw material for extrusion machines.
5. Additives can also be added to the extrusion machine to enhance the properties of the materials used.
6. Products with multiple layers, each of different material can be made by using extrusion machines.

Figure 9: Co-extrusion is used when the product is made by layers of different materials

Extrusion machines also have some disadvantages such as,

1. There is a chance of expansion of hot plastic when it is removed from the extruder. The expansion cannot be predicted thus, size deviation might occur.

https://www.youtube.com/watch?v=8D05D9CwXik

2. Different extrusion machines are required for different final products which is why more investment is required if you want all the various types of products.

Q 11) What is the cost of extrusion machines? Taiwan rates for extrusion machines?

Extrusion machines come at different prices.

The cost depends on the company’s rates that you are buying from or the type of extrusion machine.

The rates of extrusion machines in Taiwan are higher as compared to China, where some companies also offer discounts on the price of extrusion machines.

Wecoex Machines is one reliable company that sells extrusion machines at reasonable cost. It supplies high quality durable extrusion machines and extrusion lines.

Q 12) What are the easy damaged spare parts for extrusion machines?

Most of the easy damaged spare parts for extrusion machines are screw barrels for the extruder and dies with special patterns.

Extrusion machines are run 24 hours and because there is continuous supply of plastic raw material, the depth of screw barrel will wear off due to long working time.

This results in lower plasticizing and the final plastic products will not be as good as before.

Figure 10: Spare screw barrel

 In case of die, the electrical plating layer disappears after some time because of plastic material, so either electroplating is required or new spare extrusion die is used.

Figure 11: Spare pipe extrusion dies

These spare parts are easily available for any kind of extrusion machine model.

Q 13) Which areas are preferable for extrusion machines?

The use of extrusion machines is preferred for areas involving plastic, metal, and ceramic extrusion products.

https://www.youtube.com/watch?v=aM5XtOzqd0s

The areas most focused on are tube or pipe processing, door and window frame production, films and sheets, coatings, and wire insulation.

Figure 12: Different dimensions of pipes for different applications

Q 14) Is China selling the most trustworthy and reliable extrusion machines?

Yes, many Chinese companies are selling extrusion machines and extrusion machine parts to people around the world.

The companies are reliable and trustworthy because of the services they provide.

Wecoex Machines is a reliable company. It offers many services with extrusion machines such as assistance from engineers.

Wecoex Machines also advises the buyers on the best machine after knowing their requirements and sells customized machines.

The technical staff at Wecoex Machines can install the machine for buyers and also provide training to the staff at the buyer’s factory.

Q 15) Is extrusion machine used only for industrial areas?

Yes, extrusion machines are bought by industries for installation in their factories.

Extrusion machines serve the purpose of many industries for material processing.

Figure 13: Plastic sheet extrusion machine implanted in industry

 For example, plastic pipe, sheets, door and window frame manufacturing companies usually buy extrusion machines.

Q 16) Where to buy extrusion machines from?

You can buy extrusion machines from many manufacturers.

You can visit their shops or even buy online from foreign companies through their websites.

The companies also provide the shipment to your location and help to install the machines.

Wecoex Machine provides fast shipment and sends an engineer along the shipment.

The machines have high-speed output and are made with parts from reliable companies.

They will also guide you according to your requirements.

Q 17) Extrusion machines for sale?

Many Chinese companies offer discounts on extrusion machines and sell high-quality machines at a reasonable price.

You can get your plastic extrusion machine from WecoexMachines at a reasonable price. They also have discounted prices for first-class machines.

Many types of plastic extrusion machines and extrusion lines are available and you can get them at a discounted price.

The cost also includes other important services too such as full after-sales support and assistance, free spare parts, and formula support.

Q 18) Are there any manufacturers of extrusion machines in India?

Yes, there are many manufacturers of extrusion machines in India.

If you want to buy an extrusion machine from India you can find the manufacturers in the following cities:

• Ahmedabad
• Mumbai
• Indore
• New Delhi
• Ludhiana
• Thane
• Pune

Wecoex Machines also sells extrusion machines and extrusion machine lines to Indian industries.

Q 19) Which companies’ factories prefer in extrusion machines?

Different companies belonging to various industries use extrusion machines.

Companies producing plastic construction and building material and tools use extrusion machines to manufacture roofing, window, and plumbing profiles.

Figure 14: Plastic extrusions for window frames

They also make cable ducts, stair rails, safety barriers, and plastic tubes for various functions.

In the engineering industry, companies manufacture conveyer tubes, pump tubes, insulating pads, tool covers, etc by using extrusion machines.

Another big application of extrusion machine is in the lighting factories. Many products are manufactured there such as lenses, reflectors, refractors, lighting profiles etc.

Companies manufacturing medical equipment can also prefer extrusion machines for producing medical tubes. These tubes are quite thin and complex, mostly made of PVC.

Figure 15: Medical tubes

Companies that manufacture office furniture make partitions, door tracks, wall fittings, jointing profiles, and many more products.

Packaging cores such as film, tape, label, and computer cores are manufactured by extrusion machines in factories.

Shop display items like shelves, racks, poles, hangers, frames, and decorative items are also manufactured by many companies by the use of extrusion machines.

The sports industry utilizes extrusion machines for making equipment such as fishing rods, goal posts, flags, and other accessories.

Vehicle companies make vehicle trims, door, and window frames by using extrusion machines.

Q 20) What are some common examples of extrusion machines?

Many types of extrusion machines are currently available in market.

The various machines are made for production of different types of products.

The process of extrusion and construction of the extrusion machine differ a little bit from each other.

Some common examples of extrusion machines are,

• Pipe extrusion machine
• Sheet and board extrusion machine
• Profile extrusion machine

Q 21) What is the actual size of extrusion machines?

There are different diameters and lengths of screws for extrusion machines. For example, it can be 60, 75, 90, or 120mm.

https://www.youtube.com/watch?v=_MzAgB-_e2A

The L/D ratio for an extruder depends on the type of extrusion machine used and the material to be extruded and is mostly around 20:1 or 30:1 or customized.

Figure 16: The diameter and L/D of Wecoex Machine’s High Efficient Single Screw Extruder

The change in L/D ratios has an effect on different material and output.

Q 22) Can we get the diagram of extrusion machines?

Yes. You can get the diagram of the extrusion machine before buying it to make sure it meets your requirements.

Getting the diagram beforehand also helps you make arrangements for the machine according to its working style.

Figure 17: Diagram of an extrusion machine

You can get the diagram for a particular type of extrusion machine from the website of the company you are buying from.

If not present on the website you can also request the company, by contacting them, to provide you with the diagram.

Q 23) What are the basic types of extrusion moulding?

Some types of plastic extrusion moulding depending on the type of application or required product are:

Plastic pipe extrusion machines: Used to create hollow cylinders such as pipes and tubes. This type is very common and has many applications.

Profile extrusion machines: For creating uniquely shaped products such as window frames.

Sheet extrusion machines: The molten polymer passes through a sheet die. It is used to manufacture sheets of varying thickness.

Film blowing extrusion machine: It is used to create plastic bags, packing films and lamination sheets. The process involves extruding a plastic tube and then blowing air through it to form very thin walls of film.

Figure 18: Working of Blown film extrusion machine

Board extrusion machines: These machines are used for plastic molding into boards. Boards are most commonly made by PVC and are used for room decoration, sound proofing and thermal insulation.

Pelletizing extrusion machines: these machines are used to form pellets from a material. For example, plastic pellets can be made for use in other plastic extrusion machines as raw material.

Q 24) What purpose does extrusion moulding serve?

The purpose of extrusion moulding is to create products with a uniform cross-section.

Extrusion moulding is an important technique in the present era as more variety of products are coming into use.

Figure 19: Many different shapes and sizes can be formed by Extrusion moulding

Extrusion moulding can help to form products of plastic and metal into the desired shape.

Q 25) What is the process of moulding plastic from extrusion machines?

Several types of plastic are used to make plastic extrusions in different industries.

The plastic extrusion machine contains three zones: feed zone, melting zone, melt pumping zone.

In the feed zone plastic pellets or powder resin is fed via a hopper into the barrel. The rate of material being fed in depends on gravity or the weight of the polymer.

The pellets can be added with some additives to give specific properties to the plastic product.

In the melting zone, high temperature and pressure are provided to melt the polymer. This function is performed by the screws and the heater in the barrel.

https://www.youtube.com/watch?v=YXGgs9JVw9o&t=153s

In the melt pumping zone, the screw pushes the molten plastic towards the die. The plastic product is extruded out of the machine with a uniform cross-section.

The product is then passed through a cooling chamber where it solidifies uniformly.

After this, the finishing of product is done to make it smooth, by passing it through a pull roller.

The last step is to cut the product to the desired length and it is then stored for quality inspection.

 

Figure 20: The process of extrusion moulding

Q 26) What are the core principles of moulding process in extrusion machines?

The principle of extrusion moulding is simple. The process involves mechanical and thermal principles.

The screw rotates to keep the material moving towards the die and also forms mechanical heat. The heater in the barrel also aids in the heating process and melts the material.

The single screw mostly rotates in a counter-clockwise direction. Whereas, if twin screws are present, they can both take the same or different direction rotation.

Q 27) How much time do we consume in moulding plastics through extrusion machines?

The time consumed by the extrusion machine depends on the type of extrusion machine and the engine power.

For example, Wecoex Machine’s BKE25 Single Screw Extruder has a maximum output of 3kg per hour. This means that the machine runs at a rate of 3kg per hour.

Whereas, BKE120 Single Screw Extruder runs at a rate of 1100-1400kg per hour.

Injection molding process takes a lead time of 3 to 4 weeks. Lead time refers to the time the manufacturer gets an extrusion order to the time the product is delivered.

Q 28) What is the difference between injection molding and extrusion?

Injection molding is a type of plastic molding that is slightly different from the regular plastic extrusion method.

Injection molding is a good source of 3D shape products and consists of two parts: The clamping unit and the injection unit.

In injection molding, plastic pellets or resin is added through the hopper into the barrel, where heat is created to melt the material. The plastic is then pushed forward because of the high pressure by hydraulic. It is not a continuous production.

https://www.youtube.com/watch?v=b1U9W4iNDiQ

The molten plastic is then forced through an opening into a mold of the desired shape and dimensions. The material is pressurized so that all space in the mold is filled.

When the mold is filled with plastic, the cooling process starts. This happens while the material is in the mold.

The product is then ejected when it is pushed out of the mold.

Extrusion molding, on the other hand, forms 2D objects. A three-dimensional mold is not used in this type.

The material is extruded from a die to form objects with uniform cross-section. For example, pipes, window frames, etc.

In extrusion molding, the material is melted in the barrel and the screw pushes it forward. The material is forced through the die of a particular shape.

The molten plastic when passed through the die, takes up the specific shape of the die and has a uniform cross-sectional area. It can then be cut into a desirable length.

The processes have different applications because of the difference in their principle.

Injection molding is used for making three-dimensional objects and ensures minimum waste because it can recycle the plastic.

By injection molding, complex objects with detailed features can be made. Different types of plastics can also be used simultaneously in injection molding.

Figure 21: Some differences between injection and extrusion molding

This type of molding mostly creates very fine objects that do not need post-molding processing.

Extrusion molding also has its benefits. It is used to make objects with a uniform cross-section, such as pipes or tubes.

It can utilize a large variety of materials ranging from soft to hard and brittle types.

Objects with varying dimensions, colors, and textures can be formed by extrusion molding.

The products can also be processed to alter them once the extrusion process is complete.

Extrusion is a continuous production process that can set up the length of the extruding production according to the requirement. But in injection molding a customized product of fixed dimensions is made such as spoons, cantons etc.

Q 29) What is the basic salary of extrusion machine operator?

The salary of extrusion machine operators varies from one country to another and from one company to another.

In China, the average pay for an extrusion machine operator is CNY 60 per hour and CNY 120,000 per year.

Q 30) Do we require training for installing extrusion machines for new plant?

Yes. For installing or operating an extrusion machine, training is required. Laymen cannot handle the operation of the machine because of the lack of knowledge.

To prevent any damage to the extrusion machine, it is recommended that you either hire trained personnel with experience or get the training yourself.

Installation of extrusion machines is now made easier by Wecoex Machines because they send an engineer to assist you when you receive the machine.

Figure 22: Trained extrusion engineer required for the installment of machine

They also provide training to your extrusion machine operators so they can operate a particular machine without any problem.

Q 31) How much energy of electricity does extrusion machines require?

Different types of extrusion machines have different electricity consumption.

Energy is consumed by barrel heaters, driving motors, cooling fans, or pumps.

The power consumption depends on the motor in the extrusion machine. Either DC or AC motor can be used and this determines the power consumption.

Wecoex Machine has extrusion machines with AC motors. The actual of consumption will be 60% of total installation power.

You can send inquiry to Wecoex Machine to get all the data on extrusion machines.

Q 32) What is blowing extrusion machine? And how is it different from extrusion machine?

Blow molding extrusion is a type of plastic extrusion. It is used to make hollow objects like plastic bottles, watering cans, or hollow machinery parts.

The plastic pellets are first melted and then extruded through the machine in the form of hollow tubes with very thin walls.

These hollow tubes are called parisons. The parisons are then held by a metallic mold where the air is blown into them.

The parison takes the shape of the mold due to air pressure. The product is then cooled and released.

Figure 23: Blow molding extrusion

Different types of plastics can be used in blow extrusion, such as PP, PE, PET, ABS, etc.

The products are processed afterward. This is done by trimming them and cutting off the excess plastic pieces.

A spinning knife is used to scrape off the extra material and make the product smooth. The excess plastic pieces are not wasted as they can be recycled and used for the next batch.

https://www.youtube.com/watch?v=HFXY5ATm67o

The difference between the blow extrusion machine and other extrusion machines is that it contains the blowing mold for blowing air system.

These machines are limited to the creation of hollow products such as water bottles, cans, household bottles and hollow shape profiles for auto parts,