Newsletter 147: Marking HID Lamps, Cutting Polyurethane Foam, Marking Stainless Steel

SYNRAD, INC. - http://www.synrad.com
Thursday, October 5, 2006
Issue 147


Marking HID Glass Lamps	Cutting Open-Cell Polyurethane Foam	Marking Stainless Steel Dental Tools

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.

Marking HID Glass Lamps

High-Intensity Discharge (HID) lamp technology began with mercury vapor, then progressed to high-pressure sodium and now to metal halide. Metal halide lamps illuminate commercial, industrial, and retail facilities and are even making inroads into the residential lighting environment. Metal halide lamps, the most energy-efficient white light source on the market today, produce color temperatures that mimic natural light much better than previous HID lamps.

The purpose of this application request was to determine the feasibility of marking the outer glass envelope of HID lamps. After fixturing the lamp, we setup a Synrad sealed CO₂ laser and an FH Series marking head with an FLA125 lens. The 125 mm lens provides a 180-micron (0.007”) spot with a
3-mm (0.118”) depth of focus, which has proven to be the best spot size in hundreds of glass marking applications worldwide.

The 0.54” tall characters on this glass
lamp base were marked in 0.37 seconds
using 25 watts of power at a galvanometer
speed of 20 inches per second.

In WinMark Pro’s Drawing Editor, we created an eight-character text string using European, one of WinMark’s twelve built-in stroke fonts. On the Format tab, we entered a Text Height of 13.7 mm (0.54”) and added 1.7 mm (0.07”) of Extra Character Spacing. On the Marking tab, we specified a Power (duty cycle percentage) equal to 25 watts, a Velocity of 508 mm per second (20 inches/second), and a Resolution value of 150. Using these marking parameters, we created the eight-character mark shown in a cycle time of 0.37 seconds per lamp.

Cutting Open-Cell Polyurethane Foam

Open-cell polyurethane foams are used in numerous products including particulate filters, furniture cushions, bedding, and instrument packaging. In addition to its mechanical properties, polyurethane has excellent acoustical properties and is frequently used for sound control and dampening.

We performed tests on two different types of open-cell polyurethane foam to determine optimum cut speeds using 100 watts and 200 watts of CO₂ power. The first material was a 3.2 mm (0.126”) thick medium-density foam while the other type was a 24.2 mm (0.95”) thick sheet of low-density polyurethane.

We cut this section of 0.126” thick medium-density polyurethane foam at a speed of 850 inches per minute using our 200-watt Firestar f201 laser.

Our cutting setup consisted of a cutting head mounted on an XY gantry system. The head was equipped with a 63.5 mm (2.5”) positive meniscus lens that provides a 100-micron (0.004”) spot with a 1.8-mm (0.07”) depth of field over the extents of the cutting area. Even though the foam is thicker than the depth of focus, it waveguides well enough that cut edges are perpendicular to the surface. Our assist gas setup consisted of 2.8 bars (40 PSI) of clean, dry air from a high-purity (bottled) source.

For the medium-density 3.2 mm thick foam, we achieved cut speeds of 10.2 meters per minute (400 inches per minute) using 100 watts of power and speeds of 21.6 meters/minute (850 IPM) at the 200-watt power level. When processing the low-density 24.2 mm thick polyurethane foam with 100 watts, we cut at a rate of 1.3 meters/minute (50 IPM) and at a rate of 2.5 meters/minute (100 IPM) using 200 watts. In all cases cut edges are clean and free of any debris or discoloration.

Marking Stainless Steel Dental Tools

Instruments used in the medical and dental fields are primarily manufactured from one of several stainless steel alloys consisting of chromium, for corrosion-resistance, nickel, for its surface finish, and molybdenum, for its hardness. Stainless steel instruments are easily sterilized and renown for their ability to retain a sharp edge.

The requirement for this application is to permanently mark a part number on the body of stainless steel dental tools. Although the replaceable dental picks are polished stainless steel, the stainless body is bead blasted to provide a better gripping surface. To begin our tests, we setup a Firestar t60 laser and FH Series marking head equipped with an 80 mm lens. At a working distance of 74 mm (2.91”), the 80 millimeter lens provides a 116 micron (0.005”) spot over a maximum mark area of 33.5 mm × 41.2 mm (1.3” × 1.6”).

This stainless steel dental tool was
permanently marked at a speed of 2 inches
per second using 60 watts of power in a
cycle time of 0.77 seconds.

In WinMark Pro, we created a four-character text object with a Text Height of 2.54 mm (0.10”) and 0.51 mm (0.02”) of Extra Character Spacing. On the Marking tab, we set a Power (duty cycle percentage) corresponding to 60 watts, a marking Velocity of 50.8 mm per second (2 inches/sec), and a Resolution value of 400. Using these parameters, we created permanent, high-contrast readable marks in a cycle time of 0.77 seconds per mark.

Browse Synrad's Applications Database

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Contact Us:

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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