Newsletter 165: Trepanning Rubber Weatherstripping, Marking and Cutting Leather Goods, Drilling Aluminized Mylar Film

SYNRAD, INC. - http://www.synrad.com
Thursday, June 28, 2007
Issue 165


Trepanning Rubber Weatherstripping	Marking and Cutting Leather Goods	Drilling Aluminized Mylar Film

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.

Trepanning Rubber Weatherstripping

Rubber weatherstripping, which is used in many automotive and industrial applications, is no longer produced from natural rubber, but instead is manufactured primarily from polymer compounds such as silicone, EPDM (Ethylene Propylene Diene Monomer), or TPV (Thermo Plastic Vulcanizate). Although cut speeds vary slightly depending on the exact chemical makeup, rubber compounds in general (those listed above plus butyl and neoprene) exhibit similar behavior when cut or marked with CO2 lasers. Rubber’s absorptivity at the CO2 wavelength is high enough that the cutting process is by vaporization—instantaneous absorption of the beam’s energy causes the rubber to simply vaporize into a gas, while CO2 laser marking produces engraved, slightly contrasting marks.

We cut high-quality 3-mm diameter holes
through 1.3-mm thick rubber weatherstripping
in a cycle time of 0.20 seconds per hole using
200 watts of power.

This customer application was performed to test the laser’s ability to trepan, or cut, 3-mm (0.118”) diameter holes in 1.3 mm (0.05”) thick weatherstripping as it is extruded during the manufacturing process. Our test setup consisted of a Firestar f201 laser focused through a 125 mm optic mounted on an FH Series Tracker marking head. The 125 mm HP (High-Power) lens provides a 180-micron (0.007”) spot over a maximum mark field of 80 mm by 99 mm (3.2” × 3.9”). The Tracker head provides the ability to use either intermittent motion—where the weatherstripping stops during the cut, or continuous motion—where the cut is made “on-the-fly” as the material continues to move through the machine.

After creating and positioning a single 3-mm diameter circle in WinMark Pro, we set a Power (duty cycle percentage) corresponding to 200 watts and a Velocity of 50.8 mm per second (2 inches/sec). At these settings, we achieved cut speeds of 0.20 seconds per hole, which equates to a tracking line speed of 28 meters per minute (91 feet/min) in a continuous motion cutting application.

Marking and Cutting Leather Goods

Decorated leather goods are a common offering from the clothing and accessory industry. As the market for customized leather goods such as wallets, belts, purses, shoes, and jackets continues to grow, manufacturers are discovering new ways to automate the production process. One processing tool that is growing in popularity is the CO2 laser due to its ease of use and method of operation. By simply varying the duty cycle of the control signal, the laser can instantaneously switch from a power level that provides contrasting marks to a power level that can cut through the leather.

The photo shows a sample leather piece that was created using a Firestar t-Series (100 W) sealed CO2 laser and an FH Series Flyer marking head. The Flyer head was equipped with a 200 mm lens that provides a 290-micron (0.011”) focused spot with a 5 mm (0.196”) depth of focus.

This leather accessory item was marked and cut
from a larger sheet in a single operation using
90 watts of power. Mark speed was 70 IPS while
the 16 circles and oval shape were cut at a rate
of 3.5 IPS. Overall cycle time for the process
was 6.22 seconds.

Using our WinMark Pro laser marking software, we imported a vector graphic file and set a Power (duty cycle percentage) corresponding to 90 watts and then set a mark Velocity of 1778 millimeters per second (70 inches/sec or IPS). We then drew 16 circles and an oval shape and set a cut Velocity of 88.9 mm/second (3.5 IPS) for these objects (also at a power level of 90 W).

The final cut leather piece measures 147 mm by 52 mm (5.8” x 2.0”) and is 1.27 mm (0.05”) thick. As shown in the photo, edges are cleanly cut while the faster marking speed produces a highly visible, permanent mark. Overall cycle time to mark and cut each leather item is 6.22 seconds per piece.

Drilling Aluminized Mylar Film

This application involves perforating aluminized Mylar® film using a Synrad CO2 laser and FH Series marking head. With a specified position accuracy of four ten-thousandths of an inch (0.0004” or 0.01 mm) using our 80 mm focusing lens, the FH head is ideal for creating highly accurate, repeatable marks.

A 26.7 mm (1.05”) square grid was created by laying out an array of spots using WinMark Pro’s Spot tool. Instead of drawing individual spots, we created a single Spot object in WinMark and then created an array. On the Format tab, we set an Array Columns value of 42 and then set Array Rows to 42. To create the correct spacing between holes, we set both Column Spacing and Row Spacing to 0.64 mm (0.025”).

Using an FH Series 80 mm focusing lens, we
achieved drilled hole diameters of 116 microns
(0.005”) in this 1.5-mil thick Mylar film. Overall
cycle time to drill an array of 1,764 holes was
15.44 seconds.

On the Marking tab, we set a Power percentage equivalent to 10 watts and chose a Velocity of 100 inches per second (IPS). In WinMark Pro, a Spot object is marked, or in this case, drilled, by commanding the laser to remain on for the amount of time specified by the Spot Lase Duration property. At a laser power level of 10 watts, a Spot Lase Duration of 5 milliseconds (ms) is required to drill through the 1.5-mil (0.0015” or 0.038 mm) thick Mylar film. Using these parameters, we drilled 1,764 holes through the aluminized Mylar film in a cycle time of 15.44 seconds.

Browse Synrad's Applications Database

Search our online library for more applications of Synrad's sealed CO2 laser technology. Sort by material or process.
http://www.synrad.com/search_apps/Default.htm

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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