 |
|
|
|
|
|
Marking Glass-Filled Nylon Connectors
|
Scoring Alumina Ceramic
|
Laser Cutting Leather
|
|
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.
|
|
 |
Laser Marking Glass-Filled Nylon Connectors
Nylon plastic is most commonly used as a fiber to replace traditional organic fibers used in products such as fabrics or ropes. However, in solid form, its abrasion resistance, durability, and light weight also make it an attractive option for some mechanical parts such as screws, gears, and connectors. In addition, nylon provides corrosion resistance and electrical insulation, while a metal part may not. Increased strength and heat resistance are gained by glass filling the plastic. This is most commonly done to plastic automotive connectors, which need to operate in high-thermal stress environments.
The glass-filled polymer structure is more rigid and can chemically degrade, producing a color change when melted. As a result, laser marking glass-filled nylon will often produce a dark, contrasting mark, while an unfilled nylon part will not.
The finely focused laser beam is very efficient at directing the energy and resulting heat into small mark processing regions on the plastic, resulting in crisp readable marks. Other methods such as heat stamping can melt large surrounding regions of the plastic, making marks hard to read and esthetically unpleasing.
For this application, the customer was looking to improve mark quality on automotive connectors using lasers instead of the current heat-stamping method. To achieve this, a Synrad 10W laser was used with an FH Flyer marking head equipped with a 125 mm focal length lens and controlled by Synrad's Winmark Pro software. This setup produced a focused spot size of 180 mm (0.007") on the plastic surfaces. The mark file consisted of 3.8 mm (0.15") high simple stroke text with a mark velocity of 76 mm/s (3 ips). The resulting mark (seen in the top photo) provided crisp black contrast, and was completed in 1.30 seconds. When compared to the heat-stamped mark, the laser mark was more consistent and easily readable throughout. The heat stamped mark was of very poor quality due to the excessive melting of the material.
|
|
|
Laser marking produced crisp, contrasting marks on this glass-filled nylon automotive connector. Using 10W of power, the mark was completed in 1.30 seconds.
A connector with a heat stamped mark was provided to our Applications Lab as a gauge of mark quality. The laser produced crisper, more consistent marks.
Click here to install Windows Media Player
|
| |
|
|
Scoring Alumina Ceramic Plates
Alumina ceramic is a compound formed from metallic (aluminum metal) and non-metallic (oxygen) elements and is the most common of the structural ceramics. Alumina is hard enough to serve as a grinding medium or a bearing; its corrosion-resistance makes alumina ceramic a perfect lining for refractory vessels or for implantation into the human body; and its material characteristics make it a great thermal or electrical insulator.
Machining fired alumina is a difficult, but necessary procedure when manufacturing high-tolerance parts because parts made from green (unfired) alumina can exhibit subtle dimensional variations due to inconsistent shrinkage during the firing process. CO2 lasers provide a distinct advantage when processing fired ceramics because the laser's localized heating effect limits thermal stressing to a small region surrounding the cut path. In this particular application, we are actually scoring, not cutting, the ceramic. Scoring speeds are faster than cutting speeds, which further reduces heat input into the material, resulting in a fracture-free edge when the finished material is snapped along the score lines.
Generally, alumina is laser-machined on specialized cutting systems that tightly control assist gas pressure and laser pulsing parameters; although in specific cases, a laser/marking head combination can perform almost as well. In this particular application, the process called for a highly flexible system that could perform many tasks, including scoring 96% pure aluminum oxide to specific lengths.
|
|
|
Alumina ceramic pieces are scored and snapped to specific lengths. The score line was made with an FH Flyer marking head using 70 watts of power, a resolution setting of 300 DPI, and a PWM frequency of 1 kHz.
A magnified view of the scored and snapped face shows a clean edge with very slight dross on the topside, due to a lack of directed assist gas during the galvanometer-based scoring process.
|
Using a SYNRAD-supplied mounting kit, a Firestar t-Series laser and FH Flyer marking head were set up for the job. The Flyer was fitted with a 125HP (high-power) lens that provides a 180-micron (0.007") focused spot across the work area. In WinMark Pro, we created two line objects placed to cut each piece into three specific lengths. We set a Power equivalent to 70 watts, a PWM Frequency of 1 kHz, and a Resolution of 300 DPI. We then set the Spot Marking Style property to Yes and entered a Spot Mark Duration of 1.4 ms. When using WinMark Pro's Spot Marking Style property, Resolution is the key factor that determines cycle time, not Velocity. For example, reducing Resolution by one-half would cut cycle time in half since the number of individual spots per inch is reduced by a factor of two.
The alumina ceramic pieces, measuring 0.76 millimeter (0.030") thick, were fixtured in the center of the mark field and scored using the parameters described above. As seen in the magnified photograph of a piece that was scored and snapped, the face is clean with a slight amount of topside dross, due primarily to a lack of assist gas during processing.
|
|
|
Laser Cutting Leather
Natural and synthetic fabrics and leather goods are cut very well by CO2 lasers, as seen by the increasing use of lasers in the garment industry. The laser's non-contact cutting method eliminates tool wear and replacement and in the case of synthetic materials, the cut edge is sealed, which prevents fraying.
The first example shows a section of 1.9-mm (0.07") thick leather suitable for a seat covering or heavyweight jacket. The cut edge, which is usually not visible in the final product, exhibits the type of edge charring often seen when laser cutting leather. It is important to note however, that the material facing itself does not exhibit any charring or discoloration. The second photo shows a piece of suede leather measuring 0.75 mm (0.03") thick. Notice how the suede material exhibits a cleanly cut edge with no discoloration.
We set up our applications test using a Firestar f201 laser with the beam directed into an X-Y flying optics system. The cutting head was equipped with a 63.5 mm (2.5") positive meniscus lens that creates a 100-micron (0.004") focused spot with a 1.8 mm (0.07") depth of field.
The final step was to apply an air assist at 2.8 bars (40 PSI) coaxially with the beam through the nozzle. For laser processing, we highly recommend that assist air be bottled breathing grade; compressed shop air may only be used when it is dried and filtered to better than 99.9950% purity, oil- and water-free, and particulate filtered to less than 1.0 micron. |
|
|
This leather sample, measuring 0.07" thick, was cut at a speed of 450 IPM using 200 watts of power.
We cut this 0.03" thick suede leather material using 200 watts at a cut speed of 1000 IPM.
|
At a power level of 100 watts, we cut the thicker 1.9 mm leather at a speed of 5.7 meters per minute (225 inches per minute - IPM). Using 200 watts of power, we obtained cut speeds of 11.4 meters/ minute (450 IPM). When processing the 0.75-mm thick suede leather, we achieved cut speeds of 12.7 meters/minute (500 IPM) using 100 watts and speeds of 25.4 meters/minute (1000 IPM) using 200 watts of power.
|
|
|
|
|
FH Flyer / Fenix Flyer Technical Updates
Synrad Technical Updates keep you informed of recent developments related to FH Flyer Marking Head or Fenix Flyer Laser Marker products. Sign up to receive these bulletins automatically via email at http://www.synrad.com/FH_Flyer/flyersupport_subscribe.htm
|
|
|
Contact Us:
Please do not reply directly to this newsletter. E-mail questions or comments to synrad@synrad.com
Synrad, Inc.
4600 Campus Place
Mukilteo, WA 98275
Tel: 1-425-349-3500
Fax: 1-425-349-3667
E-mail: synrad@synrad.com
|
|
|
This email is intended to share useful information about CO2 laser technology with you. To be removed from our mailing list, please Unsubscribe Here.
|
|
|
Copyright ©2009 SYNRAD, Inc. All rights reserved.
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.
|
|
