Packaging 101: What Is Profile Extrusion?

Posted on March 15, 2021

Are you interested in knowing what is profile extrusion? Well, if that’s the case, you’re in the right place.

In essence, profile extrusion is the process of making plastic shapes via extrusion. If you’re still confused, we will elaborate on extrusion later in this article. Not only will you learn what extrusion is, but you will get to learn about the equipment used and how the process is completed with real-world examples.

So get your notes out, prepare yourself and keep reading to discover more.

what is profile extrusionWhat Is Profile Extrusion?

Profile extrusion is a process that extrudes shaped products that can come in a variety of forms but are not part of film or sheet products. Profile extrusion can be done on hollow and solid forms.

Products ranging from window frames to tubing to door seals are done via profile extrusion. To process hollow forms, a mandrel is used in the die to hollow out the surface. Multiple hollow parts will require several pins.

To create hollow spaces, an air source is needed to let the product maintain its shape and not collapse on itself. In most cases, an air source is pulled through to correct the cavity airflow.

If multiple materials are needed to develop a product, co-extrusion is performed. For instance, a drinking straw with several colors on it will need at least 3 extruders.

Each extruder will feed its own variation of the material into a central die for co-extrusion. Extrusion can be done on a custom or stock basis. Now that you know what is plastic extrusion, let’s take a look at the process.

The Process of Extrusion

In the extrusion of plastics, resin, or raw thermoplastic material, gravity is the main factor that feeds the top hoppers into the extruder barrel. UV inhibitors, colorants, or other additives in pellet or liquid form can be introduced into the material through the hopper.

This process is quite similar to the molding plastics injection, but the main difference is that extrusion is continual. While injection molding offers many profiles in continuous procedures, usually with reinforced, the final product is taken out of the die instead of being extruded the resin fluid from the die.

As the materials enter the feed near the barrel rear, it meets the screw. The screw forces the resin into the heated barrel, melting the resin based on the required temperature. In most cases, a heating profile is needed to utilize the proportional-integral-derivative controller to get the appropriate temperature.

This allows the plastic resin to melt and be pushed through the barrel, as well as reduced the possibility of overheating which will degrade the polymers. At the barrel front, the resin is no longer at the screw and pushes through into a reinforced screen that decontaminates the material.

A breaker plate is usually reinforcing the screen because the PSI at this point can reach 5,000, which is about 34 MPa. After going through the screen, resin enters the die.

The die is what gives the product its shape and is designed in a way that the molten plastic flows into the profile shape. Uneven flow at this point would create unwanted stress at specific points of the profile. This can cause warping of the shape upon cooling.

Practically any shape can be designed as long as it has a continuous profile.

Finalization of Extrusion

The final product is now cooled which is done by pulling the extrudate through a treatment bath. Because plastics are thermal insulators, they are quite hard to cool rapidly. Plastic conducts heat away 2,000 times slower than steel.

In a pipe or tube excursion, a sealed water bath is in a controlled vacuum to keep the form shaped and the molten pipe from collapsing. In the case of sheet extrusion, cooling rollers are used as the extruder pushes the sheet out.

Quite often, a secondary process is used before the product has finished its extrusion process. In the manufacturing process of adhesive tape, another extruder melts the adhesive and applies it to the sheet while it’s hot. When the product cools down, it can be cut into lengths and spooled.

Plastic extruders are commonplace in the creation of recycled plastic waste and raw materials after sorting, cleaning, and blending of filament into resin pellet stock that is used by the plastics industry in grande quantities.

Benefits of Extrusion

Profile extrusion is great for companies of any size. The benefits of extrusion are paramount, but here are the most important.

Efficiency Up, Cost Down

The ability to extrude large portions of plastic can make the production chain cost-effective and more efficient. Not to mention, the quality of the product is not decreased in any way.

Environment Friendly

Plastic extruding companies have taken all the possibility to utilize sustainable techniques to prevent waste of resources. Plastic companies typically discard leftover materials in large, profile extruders rarely do.

Diversity

Extrusion offers infinite manufacturing possibilities due to the variable range of products that can be used. Extrusion can create simple wires, tubes, rods, and other things. But it can also accommodate a variety of other shapes and sizes with different characteristics, such as solid, hollow, and intricate.

Nowadays, it’s commonly used by the automotive, pharmaceutical, food industries. Without extrusion, it would not be possible to create the products in demand for these industries. The technology gives way to new innovations, such as automobiles, pharmaceutical solid doses, ready-to-eat snacks, and much more.

Versatility

The process of extrusion can deliver products in the most complicated shapes. They can come in varying hardness, size, thickness and texture, and color.

Additional Benefits of Extrusion

Here are some other less prominent benefits of extrusion. They are in no particular order.

  • Manufacturing flexibility
  • Continuous operation
  • Cold extrusion enhances mechanical properties
  • Hot extrusion allows simple post-completion alterations
  • Compounding
  • Production volume
  • Surface quality

The limit in profile extrusion is in the mind.

As long as the machinery allows it and you have an idea, it can be done. Perhaps, not on the first try, but extrusion is adjustable and built upon past mistakes.

The Plastic Profile Extrusion Process Explained

Plastics are a popular raw material used in making a wide array of products, ranging from tubing to energy-efficient vinyl window frames. The plastic profile extrusion process is a comm­on procedure in the plastic-making sector because it’s readily available and easy to deploy. Many companies prefer handling plastics to other materials because petroleum-based products are easy to model. Read on to learn more about the profile extrusion process.

plastic profile extrusion processUnderstanding Plastic Extrusion

The plastic extrusion process is a straightforward procedure that involves melting down resin beads (raw thermostat material), filtering it and then designing it into a given shape. The rotating screw helps in pushing down a heated barrel to a given temperature. The molten plastic is passed through a die to give the final product its shape or profile. Filtering provides the final product with uniform consistency. Here’s a quick breakdown of the entire process.

Step 1:

The process begins by introducing raw plastic products such as granules and pellets into a hopper and feeding into an extruder. Colorants or additives are added if the raw materials don’t have some. A revolving screw facilitates the movement of raw resin through the heated cylindrical chamber.

Step 2:

The hopper’s raw materials then flow through the feed throat to a sizeable spinning screw within a horizontal barrel.

Step 3:

Different materials have different properties, including melting temperatures. As the raw resin passes through the heated chamber, it’s heated to its specific melting temperatures, ranging from 400 to 530 degrees Fahrenheit. The resin is thoroughly mixed by the time it ­gets to the end of the screw.

Step 4:

Before the resin is passed through a die to create the end product’s shape, it passes through a screen reinforced by a breaker plate. The screen removes the contaminants or inconsistencies that may be in the melted plastic. The resin is now ready to die as it’s fed into the cavity for cooling and hardening. Water bath or cooling rolls can help in fastening the cooling process.

Step 5:

The plastic profile extrusion process should be in such a way that the resin flows smoothly and evenly in the numerous stages. The quality of the final product depends on the consistency of the entire process.

Raw Materials Used in Plastic Extrusion Process

Different plastic raw materials can be heated and created into a continuous profile. Companies use a wide range of raw materials, including polycarbonate, PVC, recycled materials, nylon and polypropylene (PP).

Temperature Maintenance

Temperature plays an essential role in the entire extrusion process. Maintenance of the optimal temperatures is necessary to produce quality products. Failure to maintain the right temperature may minimize the uniform fluidity of the resin. There’s also the risk of the final product warping.

You can tell if the temperatures are not constant when pressure, friction and other variables start to develop in the extruder. It’s essential to keep an eye on the heater to ensure no increase or drop in temperature. You can manage the heat within the extruder by lowering, raising or shutting off the heaters appropriately.

Screw Design

The screw plays a crucial role in the plastic profile extrusion process as it facilitates resin movement in different stages. There’s no other moving part in the system. You should consider the design of this device as it determines the heating and feeding rates.

The melting rate, the resin size, the raw material type and the pressure required to maintain uniformity are crucial determinants of the diameter and length of the screw. You may even use two screws depending on the extruder you’re using to enable adequate mixing.

Products

Plastic extrusion is about using molten plastic to produce different shapes. The process can be used for industrial purposes or domestic uses. The technology can produce various products such as plastic films, medical packaging, hose mandrels, wire insulations, tubes and rods.

  • Electrical equipment

Extrusion is used in electrical products like the insulation of electrical wires. During this process, insulation is extruded around the wire when it’s pulled through the die. The wire must possess features such as abrasive resistance and strong electrical insulation capabilities. Insulation helps in preventing electric shocks and corrosion.

  • Profile shapes

The primary process used in the production of long cross-section shapes is extrusion. Most new homes today have vinyl slidings, developed using this procedure. The production of other profile shapes such as rain gutters and windshield wipers also uses the process.

  • Polycarbonate sheeting

Extrusion is used in the production of the impact-resistant glass replacement. Window glazing and machine guards can be made from polycarbonate sheeting. The sheeting comes in different thicknesses, depending on the purpose.

  • Solid shapes

Extrusion can produce solids in different shapes such as round, square or rectangular, and different lengths. Recycled plastics are ideal in the production of plastic decking and lumber. Extracted plastics are commonly used in fencing and outdoor furniture, such as benches. They’re better than timber because they’re weather-proof, splinter-proof and durable. You don’t have to worry about maintenance when you use these plastic pieces.

  • Pipes

Water and sewerage systems rely on extruded pipes in the form of PVC. The pipes come in different diameters depending on the need. For instance, the sewer pipes can be several inches wide, while others like taps have much smaller diameters. You can also get medical products like plastic medical tubes.

Benefits Of The Plastic Extrusion Process

Plastic extrusion has a multitude of uses in different industries. The procedure facilitates the creation of plastic products in different shapes and sizes. Some of the advantages of this procedure are discussed below.

  • One of the reasons why extrusion is widely used at the industrial level is because it has a high production capacity. Companies involved in the production of plastic products can scale without any difficulty.
  • Plastic extrusion is also cheaper than most of the other molding processes. It enables companies to manufacture different plastic products cheaply and sell them at lower prices.
  • In terms of design, this process offers flexibility that’s difficult to achieve with other molding procedures. You can get any shape from the molten plastic depending on the die used.
  • Extrusion allows for the production of a continuous profile.
  • Plastic products are recyclable. The plastic profile extrusion process not only allows for the manufacture of recyclable plastic products but also recycling of waste plastic products.

Get Plastic Extrusion From Experts

Petro Packaging Company Inc. is the best place for you if you’re looking for bulk orders of plastic extrusions and packaging solutions. We specialize in satisfying our clients’ varying extrusion and packaging needs. You can contact us or call us at 908-272-4054 even when you’re not sure what you want and we’ll be happy to walk you through the options.

Custom/Stock Extrusion for You

Now that you know what is profile extrusion, as well as why it’s useful, you can decide if you would like to try it out. However, it’s quite impractical for a company to buy all of the equipment. Instead of doing so, you can hire another company that specializes in extrusion to do everything for you.

If you’re interested in discovering our stock and custom extrusion solutions, get in touch and we will happily accommodate your needs.