Packaging 101: What Is Profile Extrusion?
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 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.
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.
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.
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
- 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.
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.