What is Plastic Welding?

Plastic welding refers to the process of forming a molecular bond between compatible thermoplastics.

Just like in the welding of metals, one has to know how to come up with a suitable weld joint, the kind of plastics being welded, and their melting points. Plastic welding results in superior strength and reduced cycle times compared to mechanically or chemically joined plastics.


There are various ways of repairing broken or cracked plastics. These include:-

  • High-frequency welding – this is ideal for plastic materials containing chemical dipoles. During the welding process, the section to be joined is pressed and exposed to high-frequency electromagnetic fields. Some amount of pressure is then applied to the welded pieces for some time to enable bonding to take place.
  •  Friction welding – as the name suggests friction is used to generate heat in two pieces and bond them together. Due to its effectiveness, this type of plastic welding is common in the automotive and aviation industries.
  • Laser welding – in this method of welding plastic, a laser beam is used to join two plastic pieces. The heat is absorbed by the two plastic sheets, thus creating a local melting zone where they meet. Laser plastic welding is not only fast but is also quite precise.
  • Hot plate welding – a metal plate is used to apply heat to the plastic sheets that need to be bonded. The metal plate is normally coated with polytetrafluoroethylene (PTFE) so that the heated plastic does not stick to its surface. Once the plastics melt and merge, pressure is applied until they cool down and are bonded.

Other techniques of welding plastic include; implant, radio frequency, ultrasonic, spin, and vibration. These processes are normally categorized by the heating method used. However, they can be classified into two major categories; internal and external heating.

Applications :

Some of the areas in which welding plastic is largely used include:

  • Assembly of manufactured domestic appliances
  • Precision welding or assembly of medical devices
  • Welding of pipelines

Welding plastic can also be used to bond dissimilar materials, such as plastics to metals or ceramics.

At Marvel’s Portable Welding, we are committed to affording our clients quality welding solutions for their repair or fabrication projects. Get in touch with us today via 302.732.9480 and for more information about our services.