What Is Extrusion Welding?

Extrusion welding is a process used to join thermoplastic materials, especially in applications requiring strong, continuous welds. This involves three general components: a suitable handheld extrusion tool, two compatible plastic parts, and a plastic welding rod. The latter is fed into the tool’s feed throat, effectively used as a glue to establish an even stronger bond between the plastic parts.

The extrusion welding machine is used to preheat the surfaces to be welded, creating a suitable melting point. Then, the filler material pushes out a hot, molten plastic stream that fuses with the material surfaces. This method is particularly effective for large or complex welds, as it provides a strong, leak-proof joint that’s key in many industrial applications.

Extruder machines can appear complicated to beginners. However, once a basic understanding is established about these tools, they are relatively straightforward to use.

Extrusion Machine Types

Are you new to extrusion welding? In that case, there are three main types of plastic extrusion machines we recommend:

• Single screw extruders
• Twin screw extruders
• Ram extruders

Single screw (or rotating screw) and twin screw are the most commonly used types – and these are covered suitably by our selection of Leister extrusion welding tools. These allow for the production of items like pipes, weather stripping, fencing, deck railings, window frames, and plastic films. These extrusion methods also offer the ability to achieve varying textures and colors in a single run and produce different shapes due to the extruder machine’s cooling system.

Along with the above three, there are several other types of extrusion machines. If you require any clarity about the differences between each machine and which would be most suitable for your needs, we are here to help.

The Benefits of Extrusion Machinery

When working with plastic material, extrusion welding presents an excellent alternative to hot gas welding. This is evidenced by the number of benefits provided by this technique. These benefits include:

• Speed: Compared to hot gas welding machines, a plastic extruder can produce an output that is up to five times faster.
• Superior weld quality: High-quality welds are delivered consistently, every time, thanks to the extruder’s continuous weld bead.
• Added convenience: Only a single pass is needed to complete welding tasks with the continuous weld bead, which is both convenient and saves time – without sacrificing quality.
• Precise control: Greater control is achieved with extrusion welding, creating a closer, more direct connection of parameters within the weld.
• Versatility: Extrusion welding machines are highly adaptable to various applications, ranging from working on small, intricate components to large-scale industrial products.

Extrusion Welding Compared to Metal Welding

While extrusion welding is primarily used for thermoplastics, it has some similarities to joining metals together. When you weld metal, there are different processes available, including TIG welding, electric arc welding, and submerged arc welding. However, at their core, all methods cover the fundamental principle of joining materials together – whether that’s a base metal or plastic sheeting.

Similarly, each process relies on heat and/or pressure to melt the material. This can also include filler materials. For example, filler metals – like plastic welding rods – can be used to form a stronger bond with weld joints.

Just remember that extrusion welding and metal-based welding processes differ significantly in the types of materials handled, the specific techniques and equipment used, and the environments in which they are typically applied. For instance, TIG welding can use shielding gas to protect against damage due to the weld’s contact with atmospheric gases.

Where Can Extrusion Welding be Used?

Plastic extruders are used across a wide variety of industries. These include:

• Automotive: A plastic extruder can be used to join together different plastic parts of a car, including the bumpers, fenders, underbody panels, and dashboard. Additionally, the process can be used to repair car damage.
• Construction: With extrusion machinery, it is possible to join polyethylene sheets for roofing, weld PVC pipe for plumbing, form window and door seals, join plastic pipes for drainage, and more.
• Furniture manufacturing: In the furniture manufacturing field, plastic components can be manipulated through extrusion welding. Join chair and table parts together, connect the components that make up the frame, and seal the edges of shelves and drawers to form a waterproof seal – these tasks can be done.
• Civil engineering: Plastic extrusion welding can join thermoplastic pipes used for water and gas distribution systems. It can also help with everything from sealing roof joints to building large-scale projects like flood barriers and sea walls.

Want to learn more about our extrusion machinery? Perhaps you want to understand how a breaker plate functions? Whatever the question, the Heatgun.com experts are here to assist.