PVC is one of a few plastics that provide nicely contrasting marks at the 10.6-micron CO2 wavelength. This Index application was performed using 10 watts of Power at a marking Velocity of 40 inches per second (IPS). Starting with WinMark Pro’s default settings, we changed Resolution to 450 and Off Vector Velocity to 250. We choose a stroke font (European) to increase mark speed, set a Text Height 0.0938 inches, and added Extra Character Spacing of 0.015”. Cycle time for the 14-character mark was 0.13 seconds.  

Many wire and tubing processes require marking to be done on-the-fly as the material is spooled. By replacing the Index head with an FH Series Tracker marking head and adding part sensing and speed encoding hardware, this same mark could be made at continuous line speeds approaching 125 feet per minute (FPM).

 
The photo shows examples of both black and white PVC tubing marked with a Synrad CO2 laser. Beam delivery for this application was through an FH Series marking head equipped with a125 mm focusing lens (180 micron spot size with a 3 mm depth of focus).