SYNRAD, INC. - http://www.synrad.com  
Thursday, March 3, 2005
Issue 107
 

Cutting Rubber Valves

Laser Cutting Thin Glass Substrates

Marking Rubber and PVC-coated Wire Insulation

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.

Cutting Rubber Valves

Thin rubber components such as gaskets and valves are used in numerous industrial products ranging from the gaskets used in pneumatic solenoids, weatherproof electrical connectors, and kitchen food processors to the valves used in oil filters and respirators.

Rubber is an excellent absorber of the 10.6-micron CO2 wavelength and although cutting is caused by chemical degradation, material breakdown occurs at low energy inputs so that cut speeds are rapid. The principal advantage of laser cutting thin sheet rubber is the non-contact aspect – laser cutting imparts no mechanical force on the rubber sheet, which is easily deformed by conventional contact cutting methods such as knives or dies.


The rubber flapper valve, shown in the image above, was cut using 100W.

In this particular rubber cutting application, an FH Series marking head is used to steer the laser beam due to the small size of the part; for larger parts such as gaskets, a precision XY table with one or more “flying optics” is normally chosen for beam delivery. The FH Series head was equipped with a 125 mm HP (high-power) focusing lens that provides a 180-micron (0.007”) spot size with a 3 mm (0.118”) depth of focus. 

The rubber flapper valve measuring 0.020” (mm) thick, was cut using 100 W at a speed of 7.5 inches per second and exhibits cleanly cut edges. The cycle time to cut each part is 0.55 seconds.

Laser Cutting Thin Glass Substrates

Many medical and consumer products are designed and manufactured using thin glass substrates including TFT and LCD displays for flat-screen monitors and cellphones. Thin glass, measuring only 30 microns to 600 microns (0.0012” - 0.0236”) thick, is easily cut with CO2 lasers and exhibits the same fine edge quality seen in many other laser cutting applications.

Thin glass cutting is an easy one-step cutting process where the laser is typically gated, or pulsed, to control heat input into the glass. The section of glass shown in the photo, measuring 150 microns (0.006”) thick, was cut on an XY table equipped with a 2.5” positive meniscus focusing optic that provides a 100 micron (0.004”) spot size and a 1.8 mm (0.07”) depth of focus. For gas assist, we used 10 PSI of compressed breathing grade air.


Thin glass substrates measuring only 30-600 microns (0.0012-0.0236”) in thickness, are easily cut with CO2 lasers.

Using 100 watts of power, we cut through the 150-micron thick glass sheet at a speed of 550 inches per minute (IPM) while an external frequency source connected to the UC-2000 Universal Laser Controller gated the laser on and off with 1.2 millisecond pulses at a frequency of 750 Hz.


Marking Rubber and PVC-coated Wire Insulation

There are almost as many types of electrical wire insulation as there are uses for wire and cable. Nylon, polyimide, silicone rubber, PTFE, XLPE (cross-linked polyethylene), PVC, and polypropylene are a few of the more common insulation coatings applied to wire. In particular, silicon rubber and PVC (or PVC-coated) insulation provides a great surface for obtaining high contrast CO2 laser marks.

To mark the wire samples shown, we setup a Firestar t-Series laser and FH Series marking head equipped with a 125 mm HP (high power) focusing lens. The 125 mm lens provides a 180-micron (0.007”) spot size with a 3 mm (0.118”) depth of focus. Using one of WinMark Pro’s built-in stroke fonts, we created a 21-character part number with an actual Text Height value of 0.062” for the small diameter wire and a height of 0.077” for the larger diameter wire.


The silicon rubber coated wire (small) and the PVC coated nylon wire (large) can be marked "on-the-fly" using a FH Series Track marking head.

The 16 AWG (small) wire has a silicon rubber coating and was marked at a Velocity of 80 inches per second (IPS) with 32 watts of power. Cycle time to mark all 21 characters was 0.14 seconds. The 10 AWG (large) PVC-coated nylon wire was marked at a Velocity of 50 IPS using 60 W in a cycle time of 0.19 seconds. Based on the cycle time, length of each 21-character mark, and the maximum field size for a 125 mm HP lens, these same marks could be made “on-the-fly” by an FH Series Tracker marking head at line speeds approaching 112 feet/minute for the 16 AWG wire and 72 feet/minute for the 10 AWG wire.


Browse Synrad's Applications Database

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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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