The marking of glass for industrial use has been done for hundreds of years. In the past the methods used have included ink stamp marking, sand blasting, air grit, acid etching, scribing etc.
Industrial applications of glass marking include:
1. Marking of safety information on safety glass used in commercial and residential construction. This includes glass areas around doors and/or entrance and exit locations.
2. Marking of glass for commercial and residential construction to identify the glass or door manufacturer [for product identification and marketing/sales activity]
3. Marking of headlamp or tail light lens in automotive applications for manufactures name, year of manufacture and/or part number. Also used in the manufacture of televisions for marking mirrors and lens.
4. Marking of serial number, product identification, or other manufacturing information for the prevention of theft and validation of warranty claims
5. Marking serial numbers, part numbers, text, or bar codes allowing for parts to be tracked though the production process until final assembly and shipment
The traditional methods of glass marking all involve contact with the surface of the glass product which exposes the product to stress and potential damage. Co2 lasers offer significant advantages for marking glass products. The RF excited sealed beam Co2 laser coupled with a galvo head and software offers the fastest, cleanest, most reliable method for marking and etching glass.
A Co2 laser can laser mark glass with bar codes, especially 2-D or data matrix bar codes, which can easily be coupled with vision systems for reading the data contained in the bar code. The use of bar codes on glass allows for the product to be tracked all the way through the production process until final assembly. This helps assure a continuous uninterrupted supply of product. The laser marked or laser etched bar code can also be used after the sale of the product for identification purposes and validation. This helps to eliminate warranty costs related to counterfeit or unauthorized products.
A Co2 laser marked or laser etched bar code can also be read by vision systems in the manufacturing process to determine the identity of the part. Examples include prescription strength of eye glass lens, or the type of front headlamp lens used in a Honda Civic. This ensures that the part is sorted and used properly throughout the manufacturing process and that the correct number of parts is produced based on anticipated sales for final assembled components.
The advances of Co2 laser marking of glass over traditional methods are extensive. These include:
No contact with the part as in scribing methods thereby reducing the possibility of breakage to and damage of the part, as well as elimination of the maintenance required for the scribe unit
No solvents, thinning, or cleaning agents to purchase and keep in stock as in the case of ink marking or ink printing systems, thereby significantly reducing costs of operation and eliminating the need for continuous maintenance associated with these various ink printing technologies
No pads for ink printing to maintain as they can fall to an angle or become turned sideways causing the printed image on the glass to appear sideways or not square
No need to stop the glass in place and make sure a secure fit with the rubber mask is formed as in the case of Airgrit marking
With Co2 laser marking for industrial glass applications the product can be marked on the fly [while moving]. If stopped or ’squared’ for marking, five to eight lines of text plus logo’s can be laser etched in less than 0.5 of a second
With Co2 laser marking no supplies are necessary and no secondary process exists for cleaning or maintenance
With Co2 laser marking changes to the mark [different text, different logo, difference shape, etc] can be accomplished with a simple click and drag command of the mouse
Co2 laser marking for glass in industrial applications is the fastest, most effective, least costly method in which to mark the product.
Jim Morin writes for Worldwide Laser Service Corporation a company that specializes in T.E.A. Co2 lasers. For more information visit http://www.wlsc.com
