Laser Welding

Laser Welding

Advantages of Laser Welding

Welding metals is the most common and generally understood use of laser welders, but plastic welding has become the norm in several industries, such as medical devices and automotive manufacturing. Things not possible just a decade ago are now being done with no additional additives, and with weld seams that are mere microns wide.

It’s easy to see why laser welding has become so commonplace. The advantages over traditional methods are numerous, and have led to enormous savings for the industries and manufacturers that have embraced it.

  • Seam Quality – weld seam structure is excellent, and often secondary finishing is not required due to little to no burring.
  • Non-Contact Welding – no need for tooling replacement due to wear and tear, and less stress on weld pieces.
  • Cleaner Processes – laser welds can often be done without filler material, and leave virtually no debris
  • Precision – a laser’s localized energy means excellent thermal control, low distortion, very close tolerances, and a very repeatable and consistent weld.
  • Speed – the ability to focus energy to exactly where it’s needed, with no spikes or dropoffs, mean material can travel through the weld path at faster speeds…up to 200 inches/min.
  • Cost – welding with lasers has been shown to reduce costs by as much as 90% through faster weld speeds, considerable energy reductions, and less required labor/weld.

Industries Commonly Using Laser Welding

The advances in laser welding have broadened its application to thousands of new products.

  • Medical Devices Manufacturing – the MDM industry requires exact tolerances, weld seams that are near invisible, and clear on clear plastic welding.
  • Aerospace – the need to weld a wide range of alloys and metals make the laser’s ability for control and precision highly desired.
  • Automotive – with a car needing some 4,500 welds in the factory, not including any done on assemblies built by suppliers, and steel, alloys, and plastic materials in use, the automotive industry has widely adopted laser welding into its processes.
  • Other Industries – Laser welded construction can be found in almost any consumer product industry, from solar panels to housewares to sporting goods to wristwatches. Large or small scale, the versatility, speed, and efficiency of a laser beam is hard to beat.

Laser Welding Methods

There are several laser welding methods available, depending on the materials being welded.

  • Deep Penetration Welding – In this method, as the beam travels along the weld path, two things occur. A) the metal is melted, and B) a small hole of vapor is created as the temperature nears evaporation levels. As the beam moves along, this vapor-filled hole (keyhole) follows, creating pressure that moves the molten metal around it. As the metal fills in behind, it does so with a very even and uniform structure. The Deep Penetration weld is noted for high speeds, greater depth (up to an inch), and high seam quality.
  • Heat Conduction Welding – In this method, as the beam follows the weld path, the metals are brought to melting temperature, but stay well below the vaporization temperature. The lower temperature keeps the weld from traveling deep into the materials, making 2mm the outside limit of weld depth. The weld seam is smooth and will not require any additional finishing.
  • Transmissive Welding – Widely used in manufacturing, the transmissive method was the first to weld plastics using lasers. The process requires a transparent (to infrared range light) upper part and an absorbing (to infrared range light) lower part, held with consistent, tight contact to each other. The beam passes through the upper layer to heat the lower. As the lower plastic reaches melting temperatures, the heat is passed to the transparent upper plastic. When both are at melting stage, the weld is achieve through the pressured contact. For transmissive welds to occur, both plastics must have similar melting ranges.
  • Transparent Laser Plastic Welding – Where transmissive welding left off, namely plastics that were “clear” to infrared wavelengths, transparent plastic welding has filled the need. First solved by infrared-absorbing doping agents and additives, which added sometimes prohibitive costs, welding clear plastic to clear was finally solved with the 2 micron laser. This wavelength has revolutionized plastic welding, and is used extensively in transparent part welding for the Medical Device Manufacturing industry where these clear parts are often used. The industry faces rigid guidelines and other bonding methods often do might not meet them.
Heat Conduction Welding

Deep Penetration Welding

Industrial Laser Welding Systems

CMS Laser builds custom welding systems around your parts, processes and needs. We pioneered “On the Fly” technology in laser production, and our systems will increase your throughput and decrease your cost per part. Contact us at 407.679.9716 or use our Sample Processing Request Form to have our Applications Lab evaluate your parts and identify the perfect laser solution for you.

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