Plastics extrusion is a manufacturing process where plastic materials are melted and shaped into a continuous profile by pushing it through a die. This process produces plastic products with a fixed cross-sectional profile such as pipes, films, sheets, and profiles. There are several types of plastic extrusion processes used in this manufacturing method. Here are some of the most common types of plastic extrusion processes.
1. Film Extrusion
For the film extrusion process, the melted plastic material is pushed through a die that produces a thin, continuous plastic film. This process is commonly used in the creation of plastic bags, shrink wrap, plastic films for packaging, and other products that require thin plastic sheets.
2. Sheet Extrusion
Sheet extrusion is used in the production of flat plastic sheets used in packaging, signs, and advertising displays. The process involves melt extruding the plastic through a die and then calendering the material. Calendering is the process of squeezing the plastic between two rollers, which serve to smooth out the surface of the sheet and to set its thickness.
3. Pipe Extrusion
Pipe extrusion is used to create hollow plastic pipes, such as those used for plumbing or irrigation systems. This process involves feeding the melted plastic material into a circular die and then stretching the plastic as it cools. The stretching process results in a thin, uniform wall thickness that makes the pipe more flexible and resistant to cracking.
4. Profile Extrusion
The profile extrusion process is used to produce complex plastic profiles with varying shapes and sizes, such as window frames or door trims. The process involves melting the plastic material and then shaping it using a die or series of dies that have mechanical plungers or sliders. The sliders move back and forth to create a continuous profile. The profile can be further cut or punched after it is formed.
5. Tubing Extrusion
Tubing extrusion is similar to pipe extrusion, but it produces tubes with a narrower diameter. This process involves feeding the melted plastic material into a die that creates the desired tube shape. The plastic is then cooled and cut to length.
Overall, the plastic extrusion process is an essential manufacturing method for making various plastic products used in different industries. Understanding the differences between the different types of plastic extrusion processes can help you choose the right method for your application. If you need help choosing the right process for your plastic manufacturing needs, contact a plastics expert for advice.