Skip links

How to Extrude Plastic: A Beginner’s Guide

Is plastic extrusion something you’ve heard of? A die is used to force liquefied material through it, as in other extrusion processes. As the material passes through the die, it takes the shape of the die. Using the same principle, plastic extrusion creates three-dimensional objects of complex shapes and sizes. Unlike metal, however, the materials used in this project are plastic.

Plastic Extrusion: The Basics

A plastic extrusion process is used by manufacturers to produce plastic components or products. Plastic pellets, powder, or pellets of raw plastic are fed into a hopper where they are forced into an extrusion machine. By using friction, the extrusion machine heats the raw plastic. During the process of heating, raw plastic turns into liquid while also becoming pressurized.

The raw plastic is shaped by a die at the end of the extrusion machine. Circular-shaped metal dies with a unique shape are commonly used in extrusion. When raw plastic is forced through a die, it takes the shape of the die. An extrusion machine allows manufacturers to create plastic products and components in a variety of shapes and sizes.

A typical extrusion machine features a large hollow screw. There are usually three zones on these screws: the feed zone, the melting zone, and the metering zone. Raw plastic is fed into the feed zone. Raw plastic is partially melted in the melting zone. The metering zone is used to finish melting the raw plastic.

Some of the most common products produced using plastic extrusion include the following:

  • Weatherstripping
  • Handrails
  • Window films
  • Insulation for wiring
  • Plumbing fixtures
  • Disposable cups
  • Electrical connectors

Is there a difference between plastic injection molding and plastic extrusion?

The process of plastic injection molding is similar to that of plastic extrusion. In both processes, heated, liquefied plastic is forced through a die. Plastic extrusion, however, is a continuous process, while plastic injection molding is not.

Plastic injection molding involves forcing liquefied plastic into a die. After the die is filled with raw plastic, it is cooled and hardened. The raw plastic is separated and removed from the die after it has hardened.

Extrusion involves forcing liquefied plastic through a die instead of into it. Manufacturing companies can produce large volumes of plastic products without interruption. As long as the extrusion machine continues to force raw plastic through the die, it will continue to produce products.