What Is Plastic Welding?

Using heat and pressure, one of the most versatile and durable joining methods in the world today has been created. Plastic welding is a form of welding that works by melting two pieces of plastic and then fusing them together to form a single, solid piece. It is a process that has been around for decades and can be used for everything from car bodies to manufacturing everyday items.

By the year 2026, the plastic welding market is expected to reach 27 billion units and is growing quickly as more and more manufacturers turn to this welding process for its reliability, efficiency and affordability.

In this article, we will be discussing the basics of plastic welding, from how and when it should be applied to its many advantages – along with a few drawbacks – to give you a better understanding of this powerful welding technique.

What is Plastic Welding?

Plastic welding is a process for joining two plastic materials that have a similar or compatible melting temperature. It is a type of welding that uses direct or indirect heat and pressure to bond plastics and thermoplastics together.

Plastic welding is commonly used in the fabrication of enclosures and components for the car industry, aircraft, electronic components and more.

Types of Plastic Welding

There are two main types of plastic welding techniques; Thermal and Non-Thermal welding.

Each type has its own advantages and disadvantages.

  • Thermal Welding

Thermal welding, also known as Hot Plate Welding, should be used when the two plastic pieces are of the same material and not dissimilar in thickness. The pieces are passed between two heated plates that causes the two parts to melt together.

This process works well for small to medium size parts and when both of the plastic pieces have similar melting temperatures.

  • Non-Thermal Welding

Non-thermal welding is a more common plastic welding method and is used to bond parts made from different materials, with different melting points.

This is done by using an ultrasonic welding system to create an intense vibration that melts the plastic pieces together. Ultrasonic welding is typically used for small to medium size parts, and works better for certain material types than others.

Advantages & Disadvantages of Plastic Welding

  • Advantages

  • Plastic welding can be used to create strong bonds between two pieces, allowing parts that may be too difficult to machine to be joined together.
  • The process is cheaper and easier to use than most other joining processes.
  • Welding does not leave behind any unsightly joints or adhesives that can weaken the strength of the parts.

  • Heat affected zones are minimal, which helps to ensure that the parts maintain their original strength and characteristics.
  • Disadvantages

  • The plastic welding process can be difficult and requires skill and precision, making it difficult to perform consistently.
  • The materials to be welded need to be of the same or compatible melting point, otherwise the joint will be weak.
  • The welded parts have a tendency to have an uneven surface finish due to the melting and cooling process.
  • It is important to use the correct welding technique for the type of plastic and joint to ensure a strong bond.


Plastic welding is a versatile process for joining two plastic materials. It can be used for small to medium size parts and depends on the type of material and joint. The welded parts will have a strong bond and a good surface finish. However, the process should be done by skillful and trained personnel to ensure the parts are joined together correctly. Citation URL: https://www. rpi-polymers. com/blog/what-is-plastic-welding/ https://www. ranar. com/tech-sheet-plastic-welding-process/

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