Laser Die Cutting: “An Update on Laser Cutting”; Printing News; May 25, 2009

There are reasons why digital 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 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 digital 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.

Advantages of Laser Cutting Technology

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 laser cutting systems 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 tool changeovers can be cut much more economically by laser systems because there is no need for multiple tool 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 that happens with tool-based die cutting systems.

Secondly, because there are no delays for tool fabrication the job turnaround with laser cuttingcompared to tool-based cutting is often the most rapid.

Third, the costs involved in laser cutting are often lower that 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 more difficult or impossible for mechanical die-based 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 cutting system. Similarly, the mechanical knicks that 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 that 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.

Better Lasers

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, laser 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 laser cutting technology was first introduced to the graphic arts industry. For some material 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 laser beams that they produce. The laser beams are better shaped, making it easier for galvo cutting systems to steer the beams faster without compromising cutting quality.

Better Software

Advancements in software engineering underlie the better performance of many different types of equipment used in the graphic arts industry, and this is especially the case with the best-in-class laser cutting systems. This better software enables today’s laser cutting systems to tightly synchronize the pulsing on and off of laser beams with artwork geometry. While the earlier systems might have left burn-through marks in sharp angle turns, these limitations do not exist in today’s modern systems. This is largely what facilitates the new capabilities to create the special features and unique products that define laser cutting’s niche. Indeed, with this better software the only relevant physical limitation in laser cutting systems is the width of the laser beam (210 microns) defining the smallest cut that it can make.

The better software also makes for faster operations. Software engineering has now optimized many cutting operations sequencing. Milliseconds are shaved from each cut such that the combined time savings of multiple cut sequences adds up to significant time savings.

Totally Digital Advantage

Another name for laser cutting systems is “digital die cutters”. That is because the better systems of today can take any vector-based drawing data file and completely set up job digitally within minutes. These systems are configured to work in-line with digital printers as well. If one is seeking a versatile piece of equipment that can be the single purchase to handle ALL cutting needs for a digital print business, laser cutters are moderately priced and highly versatile.

As we all know, most digital printing customers today want the job done “yesterday”. The beauty oflaser cutting systems is that they enable relatively instantaneous turnaround from artwork to finished products in hours.

Contract Manufacturing

For those that are considering purchasing a laser cutting system at some point, contract manufacturing services can provide an extensive production trial to better inform purchasing decisions. Reputable manufacturers of laser cutting machines provide such services.

For best practices outsourcing, a recommended first step is to gather samples provided by the contract manufacturing source. This is important because neither every laser cutting system manufacturer nor user makes use of the latest technology with superior cutting capabilities. Lower quality laser cuttingsystems that are not fine-tuned for handling transition points in part geometries have difficulties with small radii angles at which the laser energy is applied for too long such that they create undesired burn-throughs of substrates instead of desired kiss-cut or score line features. Systems that keep lasers running at the same velocity leave telltale pinholes at the start/stop points of cut out designs for similar reasons. Some laser cutting systems in fact use relatively generic off-the-shelf software that can be used to power lasers of all types. In reviewing samples it usually becomes apparent if the source is using up-to-date technology and the highly customized software that optimizes control of laser speeds and power.

If a potential source has been identified, it is then recommended that proof-of-capability samples be requested that demonstrate ability to create the specific job specifications. Sources using the betterlaser cutting systems are equipped with job simulation software that will not only be able to give detailed pricing but also accurate turnaround projections.

Tool-based or Tool-free Cutting

Laser cutting is not the best match for all die cutting applications. If the part geometries of a given job are not beyond what a tool-based cutting system can do, and especially if the run length is considerable, tool-based cutting is still likely to be the most economical option. This is because the costs of tools or delays for tool fabrication for jobs involving many millions of parts are not very significant.

For this reason, manufacturers of both tool-based and tool-free cutting systems are the recommended guides to find best-match technology. Reputable equipment manufacturers generally offer these services at no charge.

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