Wiring Harness News May-Jun 2022 - Page 10


UV Laser Marking of Wire Insulation Materials

By Igor Murokh , Ph . D . Tri-Star Technologies ___________________________

According to the IOP Handbook of Laser Technology , in 1999 approximately 22,000 laser marking machines were in use in various industries worldwide . Hexa Research expects overall laser market to reach $ 3bln USD in 2024 . It seems quite possible that in a few years everything that needs to be marked will be marked with lasers including fruits and vegetables and most definitely wires and cables .

This article describes the basic principles of UV laser marking of wires and cables for aerospace industry and its applicability to other markets .
Direct printing on wires and cables with Ultra-violet ( UV ) lasers has been extensively tested and accepted within the aerospace industry both by OEMs and by the end users . It is covered by several documents and standards issued by SAE International ( http :// www . sae . org / AIR5558 , AIR5468B , AS5649 ) and reflected in the production specification of large and small frame aircrafts for commercial , industrial , and military use . The OEM list includes Boeing , Airbus , Lockheed Martin , Sikorsky , Gulfstream , Bombardier , Pilatus , and many others . It is also used by governmental agencies such as DOD , NASA , FAA , etc . End users employ UV laser marking machines during scheduled maintenance and repair procedures .
UV lasers leave a permanent indelible high-resolution mark on the substrate surface . To understand the phenomenon , we must consider how a laser beam interacts with material . For example , the beam can be completely reflected from a surface , as a sun ray from a mirror , or propagate unaffected , as a sun ray through clear glass window . In these cases , no trace will be left on a surface . To mark a material , at least part of the laser radiation must be absorbed directly on or near the material ’ s surface .
Depending on laser and material properties there are a few possible scenarios ( Fig . 1 , page 12 ):
A . Ablation . The irradiated material evaporates , leaving relatively sharp border trenches on the surface .
B . Melting . The irradiated material melts and spills from the inside out , creating hills and valleys in the middle of a plain .
C . Burning . The irradiated material heats up and produces gaseous components that react with atmospheric oxygen , depositing a product of combustion ( such as soot ) on the surface .
D . Color change . The material
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