Last Updated on December 30, 2022 by Leizi
You’ll find plastics in a wide variety of applications wherever you go. It is a lightweight and versatile material suitable for a variety of processing methods to create a variety of rapid prototypes and products. The plastic fabrication methods include CNC machining, injection molding, blow molding, vacuum molding, plastic extrusion, etc. Each processing methods gets its own processing characteristics.
And you may be familiar with most these processing methods above, but feel strange about plastic extrusion. In fact, it has various applications in many industries: transportation, retail, construction, and more.
This article will introduce its process, advantages and disadvantages, and applications.
What Is the Process of Plastic Extrusion?
The working principle of plastic extrusion and aluminum extrusion is similar–both of them extrude the billet into a profile with a certain cross-section through a customized extrusion machine under high temperature and pressure.
The following picture shows the equipment for plastic extrusion.
Three processing steps in plastic extrusion:
1). Mixing and extruding materials
It is an important step before extrusion. The raw materials and colorants will be mixed and extruded through a long barrel plastic extruder.
2). Melting
The material will be heated in the heater under high pressure and friction in the barrel, eliminating the need for overheating. A screen then filters the contaminants out of the material, increasing the purity of the material.
3). Cooling
This step is the last step in the plastic extrusion process. The molten billet will be pressed into a mold, where it cools to its final shape.
Advantages of Plastic Extrusion:
1). Low cost. Tool designs for plastic extrusion are less costly and complicated than aluminum extrusion. In addition, since most of the materials used are thermoplastics, they can be melted or hardened multiple times without sacrificing their properties. At the same time, the plastic extrusion machines can work around the clock, so basically there will be no shortage of stock during the year.
2). Excellent ductility. Plastic is more malleable than metal. It remains highly malleable until it undergoes cooling. Once being removed from the mold, we can adjust the it in time to ensure the accuracy of the parts.
3). Flexibility. It is possible to create plastic parts in different sizes and designs if choosing plastic extrusion. As for materials selections, there are various types of plastics, and we can even mix materials to create new plastic extrusions.
Disadvantages of Plastic Extrusion:
1). Design limitations. The extrusion process is limited to plastic parts with a certain cross-section, but it cannot do anything for other types of product designs. Generally speaking, we also need to use other extrusion equipment to complete the production of other types of products. ,
2). Less precise dimensions.
Once extruded plastic leaves the extrusion machine, it begins to expand, a process that is generally difficult to control. So plastic extrusion is hardly one of the options for making precision plastic parts.
Applications of Plastic Extrusion:
1). Parts for windows and pipes;
2). Cleaning products;
3). Wire insulation.