Over the past several years, lasers have been used to mark the surface of products & packages with production date codes, product fill & expiration dates, product identification &/or composition & in some cases, for decoration. In glass bottles, high energy CO2 lasers disrupt the surface causing a visual contrast between the laser mark & the undisturbed neighbouring glass. Although the marks are generally quite legible & remain intact even after product processing & handling, the laser marks lower the breaking strength of the glass bottle. A few limited studies have indicated that the presence of laser coding does not affect glass bottle performance, however, these results are perhaps influenced as much by the location of the laser code on the bottle & type of container testing rather than the code itself. This article takes a closer look.
