One of the key elements in making laser welding applicable to eyewear repair was the development of the “free-moving” concept. In this approach, the laser welder generates a stationary infrared light pulse which is targeted through the microscope’s cross-hair. The laser pulse can be controlled in size and intensity. Because the heat generated remains localized, operators can handle or fixture items with their fingers, laser welding small areas with pin-point accuracy without causing any harm to the operator’s fingers or hands. This free-moving concept enables users to eliminate costly fixturing devices and increase the range of assembly and repair applications.
In laser welding systems, the operator controls the beam diameter (weld spot), power level (voltage) and pulse length depending on the type of alloy and joint being welded. A stereo-microscope with internal cross-hairs make it easy for the operator to align and weld the component part or assembly at the precise location. The laser welding pulse is then activated with a foot pedal. Many laser welding systems also offer the option of a cover gas, normally Argon, to ensure a homogeneous laser weld while preventing any discoloration or contamination.
Most operators can learn to use laser welding machines in a few hours. Although, to become fully proficient and benefit from the machine’s full potential, users must have a good understanding of the metallurgical properties of the alloys being welded. An experienced laser welding technician can typically perform basic manipulation of the repair item within minutes. However, laser welding training is always a good idea to learn more advanced skill sets.
Laser spot welders pose little hazard to operator’s fingers or hands while in the welding chamber. Occasionally, an operator’s fingers may experience a deflected laser pulse, but little damage is done. It is similar to a pin-prick or touching something hot. To ensure the safety of your laser welding system, always ask the manufacturer before you purchase if the machine is FDA certified according to the safety standards established by the Laser Institute of America.
Since most manual laser welders range in pulse energy from 40-150 joules of energy, or 30-50 Watts, they are normally categorized as a Class 4 laser device, the highest-powered Nd:YAG laser available. When the laser welding chamber is fully enclosed, the laser welding system meets the Class 1 safety standards, which is the safest laser to operate.