Student Resources

What is Plastic Welding

Plastic is a very versatile material. It can be molded in any shape and size and it is lightweight yet durable. It can also be mended easily if it breaks by way of welding. Plastic can be welded and there are many different types of plastic welding.
Plastic Welding Techniques
– Hot Gas Plastic Welding
This technique is also known as hot air welding. A hot air welding gun is used for this technique. To soften the plastic parts to be welded, a hot air gun is used and a a plastic filler rod. This plastic welding technique is commonly used for making small items such as plumbing fittings, heat exchangers, water tanks and chemical tanks. The plastic filler rod should be of the same material with the plastic to be welded or as close as possible. PVC and acrylic are the only exception.
– Ultrasonic Welding
This is an industrial welding technique that uses high frequency ultrasonic acoustic vibrations. The parts to be welded are held together under pressure so that a solid welding result can be attained. Ultrasonic welding is mostly used in plastic welding of of dissimilar materials. This welding process is fast and can be done continuously without interruption.
– Friction or Vibration Welding
High friction is used in this technique to weld two parts together. The friction caused by high amplitude, low frequency and clamping pressure results in a welding that is strong. This technique is the fastest heat sealing technology presently.
– Thermoplastic Welding
Thermoplastic welding uses a laser beam that creates the heat that melts the plastic parts to be welded. This is mostly used to weld flexible polymers like TPU, TPE and PVC and medical supplies.
– Solvent welding
This method uses a solvent that is applied to the parts to be welded. The solvent dissolves the polymer chains in the plastic and when the tangled polymer chains harden, a solid weld is produced.