Polymer Welding

Laser welding is increasingly employed

in the consumer, automotive and

medical device industries for

joining polymers.


New fiber lasers are significantly

extending the range

of polymers that

can be laser welded.


Laser welding of polymers is an emerging technology well suited to IPG products. The technique can compete with ultrasonic welding in some instances where manufacturing flexibility and a precision non-contact process with no welding flash is required; in these cases this technology allows reliable and cost-effective solutions for joining a range of thermally weldable polymer materials.

New technology employs a fiber laser exclusive to IPG Photonics that eliminates the requirement for an absorbing layer and enables clear polymers to be joined together. IPG's thulium fiber lasers emit a longer wavelength laser beam that is more efficiently absorbed through the thickness of the polymer allowing controlled melting to a carefully controlled depth. This recent development, called Through Laser Welding (TLW) or Mid-Infrared Laser (MIRL) welding is a high precision non-contact process and that can weld clear-to-clear polymer components. This process is highly appropriate for the type of clear polymer component widely used in the medical device industry, where darker polymers or additives are undesirable. The process is also now becoming accepted for a range of twin-walled liquid containers for the consumer industry. Recent processing developments have shown that this wavelength has many advantages including faster processing times than a 1 um laser and a much wider range of weldable polymer colors. Additionally, clamping pressures are lower and in many instances transmissive clamping plates are not required.

  polymer welding with lasers

The conventional technique for laser welding of polymers is known as Through Transmission Laser Welding (TTLW).  In this case, lasers in the 1 μm wavelength range are used to weld two thermoplastic components; one component of the joint must transmit the beam and the other must absorb it. This requires the use of either a dark component or a special costly ink or pigment for the absorbing layer. IPG supplies air-cooled fiber delivered direct diode lasers up to 200 watts average power for this process. IPG has also supplied multi-mode continuous wave fiber lasers up to 200 watts for polymer welding applications.

Both of these processes can be used on a wide range of thermoplastic materials but rely on the candidate materials to be thermally weldable with chemical compatibility and similar melt ranges.  Both processes require an average power from 100-200 watts to achieve realistic bonding speeds with good weld strength. IPG Photonics is the only supplier of 2 μm thulium fiber lasers in this power range.

Types of Polymers

Polycarbonate Thermoplastic Urethane Nylon
Polypropylene Polyethylene (HDPE/ LDPE) ABS
