Metal-coated mirrors are mostly used to achieve high reflection in the mid-infrared band(CO2 laser wavelength: 10.6um).
When the machine sits still or when you use it, the dust and moisture particles in the air attach to the reflector.
If the reflector doesn't get cleaned on a regular basis, the particles may absorb the laser energy and heat up rapidly. The heat will leave burnt dots or areas on the metal-coated film and lead to damage to the reflector, which may influence power or the result of processing to some degree. However, not all the damage will significantly affect the result.
#2 Experiment on Reflectors
Three reflectors with different levels of damage were used for the experiment to test the impact of damage on laser power.
Intact: Reflector without any obvious surface damage
Center-damaged: Reflector with a significant amount of damage at the center, but not reaching the bottom layer of the coating
Edge-damaged: Reflector with multiple damages in non-central areas
Influence on Output Power of the Laser
A control-variable approach was taken to test the change in output power on a functioning machine while changing only the reflector.
Based on the tests, edge damage resulted in a 0.59% power loss, which has a negligible impact on the overall system power.
Center damage, without complete blackening, caused a 1.94% power loss, which also had a relatively minor effect on system performance.
Influence on Cutting
Building on the previous results, additional tests were conducted, such as cutting 20mm acrylic.
Based on the results above, there were no discernible differences in processing outcomes when using the three reflectors.
The reflectivity of metal film mainly relies on its thickness, smoothness, and purity.
Surface damage and contamination have minimal impact on the optical system and processing ability unless they cover a large area relative to the total surface.
Minor surface damage or dirt has little effect on the reflectivity as long as they are not severe and don't penetrate the film layer since the reflection occurs at the surface of the reflector.
The reflector is an optical precision accessory that requires regular maintenance and care.
Use latex finger cots or gloves to avoid contaminating the optic surface when installing or removing the reflector. If proper tools are unavailable, avoid direct contact with the mirror's surface, but hold the edge of the magnetic suction ring instead.
Prior to cleaning, blow away the dust before cleaning the mirror with nitrogen or compressed air, or a rubber air blower pump if proper tools are not available.
Note: Skipping this step may lead to surface scratches and irreversible damage.
Use dust-free cotton swabs or lens paper moistened with a special cleaning solution consisting of anhydrous ethanol to gently wipe the mirror surface in one direction.
Note: Avoid wiping back and forth.
If needed, apply a small amount of isopropyl onto the dirty area before wiping it with moistened dust-free cotton swabs or lens paper.
Storage and protection:
After cleaning, dry the mirror with a soft cloth, especially if using slow-evaporating organic solvents like 75% disinfectant alcohol. Liquid stains can harm the coating if not thoroughly wiped out.
When not in use for an extended period, store reflectors in a dry and dust-free place with a protective cover.
Regular cleaning is recommended every 2-4 hours of use to maintain mirror reflectivity and service life.
As a precision component, the reflector is also a consumable item. Airborne dust or processing residue can inevitably adhere to its surface. If the mirror's surface is seriously damaged during processing under such conditions, it should be replaced.
If there are black damage spots on the mirror's edge or center (as shown below), indicating damage deep enough to affect the film layer's bottom, the reflector should be replaced.
Within three months of delivery, contact after-sales service at: email@example.com for serious mirror damage, and we will provide a free replacement.