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Lenses operate in hostile environments. The hot molten or gaseous material is produced in the cutting process are contaminants. High pressure gases produce turbulence, which moves the contaminates around, while the flow creates a vacuum effect at the nozzle. These contaminants often wind up on the lens, which reduce lens life.

Low levels of contaminants will reduce transmission and cutting power, while higher levels and surface contamination cause thermal lensing. Thermal lensing occurs as the lens heats up, causing it to distort. The physical changes in the lens may cause 4 to 5 mm of vertical movement of the focal point. In turn, this results in poor cutting or even loss of cut. At extreme levels of contamination, differential expansion occurs, resulting in lens fracture or an explosion and expensive repairs.

Cleaning the lens can extend the life of the lens coating. Frequent cleaning reduces the build up of contamination, which results in more consistent operation and maximum cutting power. Some residue, which tend to burn in or bond the contaminant to the lens surface, can be removed before repeated heating cycles.

How often should you clean a lens depends on the material being cut. Most manufacturers recommend cleaning lenses once a week. This frequency should work for the average user unless the cut quality becomes inconsistent. However, some materials that produce more residue or spatter—stainless, aluminum or galvanized—require more frequent cleaning. Trial and error, based on the materials being cut, will allow an operator to optimize cleaning frequency. Mate does offer an number of convenient and easy-to-use Mate Lensmate™ Maintenance Supplies, laser lens maintenance accessories that will help you improve optics life and performance, This line includes our Lensmate Inspection System, a polarizing filter the allows a visual inspection of the lens in 30 seconds or less, and Lensmate cleaning tissues and wipes.