Extrusion: Definition, History, & Process

What Is An Extrusion?

Extrusion is the process of creating objects with a fixed cross-sectional profile by pushing material through a die of the desired cross-section. A die is a thick, circular disk that contains one or more openings that create the shape of the desired profile. The extrusion process is advantageous compared to other manufacturing processes due to its ability to create complex cross-sectional designs as well as the ability to work with brittle materials.

History of Extrusions

In 1797, Joseph Bramah patented the first extrusion process. It involved making pipe out of soft metals. The metal was preheated and then forced through a die using a hand-driven plunger. Twenty-three years later, Thomas Burr used this process combined with a hydraulic press to create the lead pipe. Then in 1894, Alexander Dick extruded copper and brass alloys using the same process. Today, we see extrusion made from a variety of die shapes and materials.

Extrusion Manufacturing Process

The extrusion process begins with preparing the selected die and moving it to the extrusion press. The material is then preheated and loaded into the extrusion press. A ram pushes the material into the container of the press. The material expands to fill the container walls before emerging from the die as an extruded profile. The extrusion is then cooled to room temperature, stretched for proper alignment, and then cut to length. If additional properties are required, the profile then goes through heat or cold treatment, a finishing process, and/or fabrication.

This process is much like squeezing toothpaste from a tube. Your fingers act as the ram, pushing the toothpaste (material) out of the tub opening (the die). The toothpaste comes out in the shape of the tube’s opening.

Extrusion Die Shapes

The terms “shape” and “profile” are more or less interchangeable. When discussing an extruded shape or profile, it refers to its cross-section. Essentially, the “shape” of the die or tooling through which it is extruded. This can be anything from a simple “U” shape to more complex, multifaceted shapes with intricate edges and interior details.

Custom Shapes for Extruded Products:

  • “D” profiles provide a soft seal and can be solid or hollow
  • “L” profiles for corner applications
  • “T” profiles are commonly used for food packaging
  • “U” profiles provide edge protection for panels
  • “E” profiles contain a hollow seal and groove
  • “H” profiles seal two adjoining panels
  • Omega profiles have a t-shaped bar and bulbous seal
  • Wedge profiles to secure panel and glazing units

Materials Used In Extrusion

Selecting the right material for your extruded products is one of the most important steps when planning your project. Choosing the right extruded products manufacturer will ensure that your part is made successfully, performs properly, and is delivered to you at the lowest possible cost.

Common Materials for Extruded Products:

  • Chloroprene (Neoprene®)
  • EPDM
  • Natural rubber
  • Nitrile (Buna N)
  • SBR
  • PVC
  • HMW PVC (High Molecular Weight)
  • TPV
  • Standard and custom blends, and many more

If you’re not sure what material is the right choice for your extruded products, our experienced staff can assist you in selecting the proper material for your needs. We stock most of the common commodity-grade materials and a wide range of engineering-grade plastics, rubbers, and silicones. Our relationships with plastic resin suppliers ensure our ability to procure any materials that your job may require at a competitive price.

Custom Extrusions from Northwest Rubber Extruders

We have been a full-service provider of rubber extrusions, silicone extrusions, and plastic extrusions for over 40 years. We offer short-run, quick-turn manufacturing, as well as full production runs at quantities in the tens of thousands. In addition to our standard extruded products, we also deliver custom rubber extruded products, plastic extruded products, and silicone extruded products that are tailored to match our customers’ unique requirements.

We utilize “lean” production processes and new, innovative tools and techniques to produce the highest quality custom extruded products while maintaining very short lead times. All extrusion dies are made in-house, and our laser micrometer monitoring process ensures tight tolerances for accurate profiles. We also offer a wide variety of value added services to make our rubber, plastic, and silicone extruded products even better.

Northwest Rubber Extruders is the only manufacturer you need for custom plastic extrusion, rubber extrusion, and silicone extrusion. Request a quote on extruded products for your application, or contact us for more information on our extrusion capabilities.

NW Rubber Extruders