An Update on Laser Cutting

There are several reasons why printers should take a new look at laser cutting technology. Recent technological advances, combined with the growing availability of contract manufacturing services offered by manufacturers of laser cutting equipment, make a wide range of new products possible.

First, for those not familiar with laser cutting technology, a brief breakdown on how it works. Lasers cut by melting material in their beam path. The types of lasers used in the graphic arts industry are CO2 lasers that pulse on and off to effect cuts. There are two basic designs—gantry systems, which are basically XY plotters that physically move lasers around according to the artwork geometry to be cut; and galvanometer (galvo) systems that instead make small adjustments in mirror angles to move the laser beam in different directions.

Advances in galvo technology are the ones most important to printers, as they are the ones that are likely to provide the fastest turnaround on short runs. And now the best-in-class laser cutting machines run at high speeds, as fast as 90 meters/minute, capable of working in-line with full-speed digital printing presses.

The New Advantages

Because laser cutting systems are tool-free—i.e. do not require any dies or tooling to make cuts—they are able to transcend typical mechanical/physical limitations of tool-based die cutting systems. For one thing, the range of substrates that can efficiently and precisely cut is broader. Adhesive substrates, which quite literally gum up the works of tool-based die cutting systems, are readily handled by laser cutting systems.

Abrasive substrates that wear down tooling and necessitate frequent changeovers can be cut much more economically by laser systems because there is no need for multiple replacements to get jobs done. Very thin or flimsy materials can also be better handled by laser cutting as they avoid the tendency to tear, and difficulties in controlling registration.

Secondly, because there are no delays for tool fabrication, the job turnaround with laser cutting compared to tool-based cutting is often more rapid. Third, the costs involved in laser cutting are often lower than those for tool-based die cutting, because there are no costs for tool fabrication, repair or storage.

Fourth, and especially relevant in light of recent technological advances, laser cutting systems can easily make special features—small features with sharp angle cuts, perforations, score lines, kiss cuts, creasing, consecutive numbering, personalizations, etc.—that are difficult or impossible for mechanical systems. For example, while metal dies would be expected to have some difficulties with corners less than 30 degrees, this is not in any way challenging for a laser-based system. Similarly, the mechanical nicks one often needs to make in sharp angled parts made with steel rule dies to facilitate parts extraction are not required with laser cutting systems.

Lastly, another advantage of laser cutting is that it removes material at the cut line. This means no extra extraction process is required, an often demanding operation when complex parts with various internal features are being die cut by tool-based systems.

Laser Quality

The speed of laser cutting systems is in part determined by the wattage of the lasers at the core of the system. In recent years, manufacturers have continued to come out with improved lasers with relatively more power at lower prices. Now, 200-watt and 400-watt lasers are widely available at competitive prices, which was not the case when the technology was first introduced to the graphic arts industry. For some applications, these higher wattage lasers do cut faster.

It is not only the speed of lasers that has been improved, but also the quality of the beams they produce. The beams are better shaped, making it easier for galvo cutting systems to steer the beams faster without compromising cutting quality.

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