Laser Cutting Machines: “Casting a lasers eye-view on digital die cutting”; Converter; November 2006

By Bill Knotts, VP and Karl-Heinz Jordan, European Sales Director, Spartanics

Is it time to add digital die cutting (a.k.a. laser cutting) to your finishing department?

The prototyping-on-the-fly capabilities of laser cutting systems deliver a competitive advantage to label converters and to others who have similar needs for fast job turnaround. The more sophisticated laser cutting systems on today’s market are also valuable as production tools for longer runs, especially when the product features and/or the substrates are an especially good match with the capabilities oflaser cutting. If you haven’t investigated laser cutting technology within the last few years, you may have misconceptions about what laser cutting can and cannot deliver. Here is a quick snapshot of laser cutting technology as it stands today—

Main Advantage—Eliminate Tooling Costs and Delays

The big PLUS of laser cutting technology stems from its elimination of tooling. All the other cutting systems used by converters – rotary die cutters, platen presses, optically-registered gap presses, etc.—involve some sort of tool, and the inherent delay in job turnaround that tooling fabrication requires. In contrast, the latest models of laser cutting systems can be set up in minutes by importing any vector based drawing into the operating software of the laser cutting system.

For short runs, the cost of tooling may also be a significant factor. This is another reason why laser cutting outperforms tool-based systems for converting operations where controlling prototyping costs has a significant impact on profitability.

Handles Difficult-to-Cut Substrates

Because laser cutting systems are tool-free that translates into an advantage in cutting certain substrates that pose challenges for tool-based cutting systems. For label converters, cutting adhesives is far easier with laser cutting systems because the tendency of adhesives to literally gum up the works is eliminated.

Ease with Special Features

The more recent models of laser cutting systems differentiate from their predecessors largely through the better software that they employ to synchronize the pulsing on and off of laser beams with artwork geometry. While the earlier systems might have left burn-through marks in sharp right angle turns, these limitations do not exist in today’s modern systems. In turn, this adds to laser cutting technology’s ability to handle the special features that are important to many converting applications— perforations, score lines, kiss cuts, consecutive numbering, creasing, personalizing, etc.

The only relevant physical limitation is the width of the laser beam—250 microns—that defines the smallest cut that a better digital die cutting system can make, and which far exceeds the capabilities of a male/female hard tool die system. Any die-based cutting system would likely have difficulties in producing corners in parts that are less than 30 degrees, but this is not in any way a challenge for today’s laser cutting technology. And, laser cutting systems allow you to skip the step of creating mechanical knicks to facilitate parts extraction that are often required in a die-based cutting system.

New Production Run Capabilities

There are two basic types of laser cutting systems. Gantry systems, which are essentially XY plotters that physically move lasers around to cut out the needed geometry, are inherently slow. Galvanometer (galvo) systems, which make small adjustments in mirror angles to move the laser beam in different directions, have a speed advantage over gantry systems.

The better galvo systems of today are faster than the first models that were available several years ago for several reasons. For one thing, laser manufacturers continue to come out with better model lasers each year and more reasonable prices. 200 watt and 400 watt lasers are readily available at competitive prices, which was not the case when laser cutting technology was first introduced to the converting industry. The quality of lasers has also improved in that they make better shaped beams that are more readily steered by galvo systems at greater speeds. Most importantly, the better laser cutting systems have much improved software that shaves milliseconds off of most operations that cumulatively means a faster cut when compared to the earlier generations of galvo technology.

While laser cutting systems are being used as full production tools they do not compete with tool-based cutting systems geared for especially long runs where tooling costs are insignificant contributors to overall job cost, set up time is similarly not of much weight, and where the special features and substrates are not difficult for a tool-based system.

A Word of Caution!

A word of caution—it is important to THOROUGHLY check out laser cutting technology before purchasing it. Many of the laser systems being sold in the market today use standard lasers that are not customized for converting applications, and do not have the software improvements that underlie better synchronization of laser beams with artwork geometry. A good reality check usually begins with sending equipment manufacturers samples of both the substrates and artwork in specific applications to ensure that the resulting product is without the burn-throughs or pinholes that indicate poorly shaped and inadequately controlled laser beams. Contract manufacturing services offered by reputable laser cutting equipment manufacturers as extended production trials of specific laser cutting systems prior to purchase are also advisable in most scenarios.

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