Laser Perforating Card Stock

Perforations and scoring lines are commonly used in the paper industry as an aid in folding containers or ripping packages. Some applications are as simple as creating fold/rip lines on envelope and packaging material or as complex as perforating/cutting decorative designs in cards.

Laser perforating has several advantages over more traditional methods like mechanical hole punching because hole size and spacing can be finely controlled by simply adjusting the pulse frequency and pulse duration of the laser's control signal. Another benefit is the non-contact nature of laser processing ensures a consistent process over long periods of time with no need to change or sharpen cutting or punching tools.

For this particular perforation application, a 0.29 mm (0.011”) thick piece of card stock required a perforated line to mark a folding location, that later can be torn and opened by the recipient. The laser perforating process is an attractive option because it easily perforates paper and card stock materials in a consistent manner at very high line speeds.

For the laser test, a Synrad 200 W laser was used in conjunction with the Applications Lab’s XY table and a cutting head outfitted with a 2.5” focal length lens that provided a 0.1 mm (0.004”) focused spot size. Bottled, breathing-grade air was used as an assist gas at pressure of 1 PSI through a 0.9 mm (0.035”) wide nozzle to protect the focusing lens. With this setup, the card stock material was perforated at a velocity of 635 millimeters per second (1500 IPM). The laser’s 5 kHz control signal was set at a 30% duty cycle and then gated at 500 Hz. This pulse train created 0.65 mm (0.026”) elongated holes spaced 0.65 mm (0.026”) apart and the resulting line of perforations are very consistent in size and spacing across the card stock.

Laser Marking Polypropylene Rings

Marking polypropylene with a CO₂ laser does not produce an actual color change, but does create some depth relative to the unmarked surface. This engraved mark catches the light and provides a visible mark that is easily read when viewed at certain angles. These types of marks work well for date codes, serial numbers, and part numbers on products that need to be unobtrusive during regular use, but do need to be available for traceability reasons.

For this particular application, a clear polypropylene ring used in the filtering section of an air purifier needed to be marked with a seven digit identification number. The need for a permanent mark was one of the project requirements that made laser marking the choice over other traditional marking methods.

Our validation test setup consisted of a 100 W laser and an FH Flyer marking head— equipped with a 200 mm focal length lens—all controlled by our WinMark Pro laser marking software. This setup produced a focused spot size of 290 mm (0.011”) on the polypropylene ring surface. In WinMark Pro, a text object was created with 3.8 mm (0.15”) Text Height using the default Simple Stroke Font. The Power property was set to a duty cycle equivalent to 100 W and the Velocity property was set to 1016 millimeters per second (40 IPS). At these settings, the seven-character mark was completed in a cycle time of 140 milliseconds (ms) per piece.

Firestar V30 - New Water-Cooled Model

Now available in a water-cooled version, our line of compact firestar v30 OEM lasers are the ideal size for integration into desktop engravers and marking & coding systems. Designed with the needs of our OEMs in mind, the v30's air-, fan-, and water-cooling options allow OEMs to tailor their products to meet the most demanding customer applications.

Specifically the OEM water-cooled v30 was developed for use in clean room environments, where cooling fans are not permitted, and/or for installation in full wash-down (IP65 rated) enclosures. In addition, the water-cooled v30 is 3 inches (7.6 cm) narrower than the fan-cooled version—a significant difference in those laser applications where space is at a premium.

Water-cooling means the OEM v30 can maintain peak performance over a wide range of ambient temperatures and with superior power stability, fast rise/fall times, and excellent near-field beam quality, the OEM v30 laser continues to be the ideal component for laser engravers and laser marking systems.