What are air bubbles in the CO2 laser tube and what to do to avoid them?

First of all, for those who do not know what these elements are, the air bubbles that form inside the laser tube are small concentrations of air that are produced when changing the tube or chiller water, which causes air to enter and the bubbles form. This is not a big problem, but they should be removed as soon as possible to ensure good lightning quality as well as results.

These small concentrations of air, located in the cooler chamber of the laser tube, can cause a reduction in heat transfer. The size of the bubbles directly affects the efficiency of the chamber, the larger the bubbles, the less it will cool the system. We have to take into account the temperature that is recommended to work with the laser tube, which should not exceed 25 degrees, thus ensuring better performance.

If these air concentrations are located in the optical system of the tube, either the final mirror or the lens, they can overheat, completely misaligning the laser beam.

Possible common causes for air concentrations are:

  • Inlet of air into the cooling system via leaking connectors
  • Pump cavitation
  • Air is not extracted during initial start-up

How can we prevent them from forming?

  • Make sure all hoses are airtight to prevent any air entry.
  • Use hoses of the same diameter throughout the system.
  • Do not use connectors or restrictive gaskets to extend hoses.
  • The water level in the tank must be correct to avoid splashing and oxygenate the coolant.
  • Verify that the hoses are not bent or have narrow bending radii.

How to eliminate bubbles?

  • To remove large air bubbles, you can wait for the bubbles to disperse naturally, although sometimes this does not work with very large bubbles in the optics cooling system. Or, you can tilt the laser tube or machine to help the bubbles come out of the tube.
  • Turning the laser tube so that the water outlet is the highest point of the cooling loop will prevent air bubbles from forming around the cavity of the reflective mirror.
  • Pinching the water cooling tube to create a pressure differential. When released, the bubbles should come out.
  • It is essential to use the appropriate cooling systems for each tube and machine size.

In short, first we have to make sure that the system is a closed-loop, there is no air inlet. If there are bubbles, follow the steps above to remove them and, of course, carry out preventive maintenance.

Do you have doubts about the maintenance of your laser machine? Remember that Perez Camps offers maintenance service for our machines.

  • Què són les bombolles d'aire en el tub làser CO2 i què fer per a evitar-les?