Cleaning and Correct Positioning of CO2 Laser Lenses

Although the optical lenses in high-power CO2 laser systems are consumables, we always hope to use as few as possible to extend the service life of the laser and reduce the cost of use.
During the replacement process, the placement, inspection, and installation of the co2 laser lenses should be careful to prevent the lenses from damage and contamination. After a new lens is installed, it should be cleaned regularly. This process is quite simple. Correct operation will extend the service life of the lens and reduce costs. On the contrary, it will reduce the service life.
When the laser is working, it is inevitable that the optical components in the laser will contact suspended matter. When the laser cuts, welds, and heat treats the material, a large amount of gas and splashes will be released from the working surface, which will cause damage to the lens. When contaminants fall on the surface of the lens, they will absorb energy from the laser beam, resulting in a thermal lens effect. If the lens has not yet formed thermal stress, the operator can disassemble and clean it. Of course, some method should be used to avoid damage to the lens and further contamination.

1. General Operating Principles

During the installation and cleaning of the co2 laser lens, any sticky matter, even nail marks or oil droplets, will increase the absorption rate of the lens and reduce the service life. Therefore, the following precautions must be taken:
1) Never install the lens with bare fingers. Wear finger cots or rubber gloves.
2) Do not use sharp instruments to avoid scratching the lens surface.
3) When taking the lens, do not touch the film layer, but hold the edge of the lens.
4) The lens should be placed in a dry and tidy place for inspection and cleaning. A good workbench surface should have several layers of cleaning paper towels or paper wipes, and several sheets of lens cleaning tissues.
5) Users should avoid talking over the lens and keep food, drinks and other potential contaminants away from the work environment.

2. Correct Cleaning Method

The only purpose of cleaning the co2 laser lens is to remove contaminants from the lens without causing further contamination and damage to the lens. To achieve this goal, people often use methods with relatively low risks. The following operating steps are set up for this purpose and should be used by users.

• First, use an air ball to blow off floating objects on the surface of the component, especially for lenses with tiny particles and flocs on the surface. This step is necessary. But never use compressed air from the production line, because the air contains oil and water droplets, which will deepen the contamination of the lens.
• The second step is to use acetone to lightly clean the lens. This level of acetone is almost water-free, which reduces the possibility of lens contamination.
• The cotton ball dipped in acetone must be cleaned under light and moved in a circular motion. Once the cotton swab is dirty, it must be replaced. Cleaning should be completed in one go to avoid wave lines. If the co2 laser lens has two coated surfaces, such as lenses, each surface needs to be cleaned in this way. The first surface needs to be placed on a layer of clean lens paper for protection.

• If acetone cannot remove all the dirt, then use vinegar to clean it. Vinegar cleaning uses the dissolution of dirt to remove dirt, but it will not cause damage to the optical lens. This vinegar can be experimental grade (diluted to 50% strength), or household white vinegar with 6% acetic acid. The cleaning procedure is the same as acetone cleaning, and then acetone is used to remove the vinegar and wipe the co2 laser lens dry. At this time, the cotton ball should be changed frequently to completely absorb the acid and hydrate.