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SYNRAD, INC. - http://www.synrad.com |
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SYNRAD's sealed CO2 lasers are used in a variety of industrial processes including cutting, welding, drilling, and marking. This news brief showcases some of the interesting materials and products that are processed daily by Synrad's line of CO2 lasers and marking heads. |
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With hundreds of Synrad CO2 lasers and FH Series marking heads installed on production lines in major glass manufacturing facilities throughout the world, we know a thing or two about glass marking. In the past, we have shared mark parameters that enabled you to achieve the best glass marks possible. In this article, we will describe another method of marking glass that allows you to create laser marks in black or in many other colors. The first photo illustrates a typical 10 watt glass mark, in this case, a logo from our imaginary glass company—the XYZ Window Corporation. This type of mark is by far the most common, a subtle yet readable mark usually seen in the corner of your window panes or door glass. We created the XYZ logo in our WinMark Pro laser marking software by creating two separate text objects and then importing a vector graphic file. In this example, we set the following mark parameters for the first Mark Pass: Velocity – 25 inches per second (IPS), Power – 10 watts, Resolution – 300, Spot Marking Style – Yes, and a Spot Mark Duration of 5 (0.5 ms). We then made two more Mark Passes, changing only the Power setting to 12 watts. By using a 125 mm focusing lens with a 180-micron (0.007”) focused spot, we were able to control and contain the ring fractures to diameters of 200–300 microns. This particular chip-free logo, measuring 45 mm × 35 mm (1.8” × 1.4”), was produced with 10 to 12 watts of power in a cycle time of 7.51 seconds. In cases where a more distinct mark is required (to replace a silk-screened mark on automotive door glass for example) or when creating customized art on glass, the use of proprietary coatings can be used. These coatings, available in several colors, are applied to the substrate (glass, metal, plastic. etc.) prior to marking and then fused to the material surface by the intense heat of the laser’s focused beam, resulting in a permanent bond. |
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The second photo shows our XYZ Window logo after marking another piece of soda-lime float glass. We chose a black coating (available in an aerosol spray), applied it to the glass and then allowed a few minutes drying time. In our mark file, we changed Velocity to 16 IPS, Power to 30 watts, and set Spot Marking Style to No so that we marked continuous vector lines instead of discrete spots. Because we are bonding the coating to the glass surface without inducing fracturing, we set the Mark Passes property to 1. Using these settings to mark the same 45 mm × 35 mm logo, we achieved the high-visibility mark shown at a power level of 30 watts in a cycle time of only 1.97 seconds. By setting power levels between 20–25 watts and velocities of 24–32 IPS, you can also use this same process to mark large, decorative bitmap images on glass using a 370 mm lens (0.021” focused spot) over an area as large as 241 mm × 297 mm (9.5" × 11.7"). When raster-scanning bitmap images, lower powers at higher speeds create the same permanent bond without heating the glass to a point where uncontrolled fracturing occurs. |
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This metal cutting application involves cutting 0.28 mm-thick (0.011”) woven stainless steel mesh where each individual strand is made of 0.165 mm (0.0065”) diameter stainless steel wire. The combination of wire diameter and the plain Dutch weave provides a 60-mesh material, which is about the same mesh count per inch as the filter installed on your kitchen faucet. To perform our trials, we first set up the cutting head on our XY stage with a 63.5 mm (2.5”) positive meniscus lens that provides a 100-micron (0.004”) focused spot with a 1.8 mm (0.07”) depth of field over the extents of the table. Although the optical setup for cutting 316 stainless steel mesh is similar to the setup for cutting solid stainless plate, the most important variable is the type of assist gas. For the woven mesh, we used 5.5 bar (80 PSI) of high-purity air—breathing grade—instead of oxygen. The air assist contains enough oxygen to enhance cutting without causing run-away combustion of the fine wire mesh. |
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Using a Firestar f-series laser at a power level of 200 watts, we cut lengths of this woven stainless steel mesh at speeds of 5.08 meters per minute (200 in/min). The cleanly cut edge exhibits a slight discoloration, which is commonly seen when laser processing stainless steel. For applications that cannot tolerate any discoloration (or applications where the stainless pieces are later welded), the use of high-pressure nitrogen assist provides exceptional results, albeit at much slower cut speeds.
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 As the photo shows, the laser-cut fabric edge is clean and sealed, which eliminates fraying, while the fiberboard backing exhibits very light charring. |
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For this cutting trial, we were asked to cut a 5.3 mm (0.210”) thick automotive interior panel consisting of a 0.5 mm (0.020”) thick woven fabric that was stretched over 2.8 mm (0.110”) foam padding and glued to a 2 mm (0.080”) fiberboard backing. To demonstrate feasibility, we set up the cutting head on our XY gantry system with a 63.5 mm (2.5”) positive meniscus focusing lens to achieve a 100-micron (0.004”) focused spot with a 1.8 mm (0.07”) depth of focus and then we selected clean, dry air at 2.7 bar (40 PSI) as the assist gas.
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Happy Holidays from all of us at Synrad!
Our next Applications Newsletter will be sent |
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Synrad, Inc. 4600 Campus Place Mukilteo, WA 98275 Tel: 1-425-349-3500 Fax: 1-425-349-3667 E-mail: synrad@synrad.com |
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SYNRAD and Synrad product names are trademarks or registered trademarks of SYNRAD, Inc. All other trademarks or registered trademarks are the property of their respective owners. |
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