Laser Die Cutting: “Examining The Benefits of Laser Technology”; Specialist Printing Worldwide: Issue Two: 2010

Digital printing has been addressing the need for shorter runs and specialty products for the past several years. As a result, converting equipment manufacturers saw an opportunity to move into the digital age by perfecting laser die cutting through software and hardware advancements. How can this help your company? Let’s take a look.

Beam Delivery

For all practical purposes, laser cutting technology equipment is broken into two areas including Gantry and Galvanometer systems. Gantry systems are known as XY plotter systems because they either move the laser above a sheet of material or move the material in XY in order to position the head in a predetermined area. These systems are best utilized in wide format applications (600mm or above), when cutting thicker material substrates (800 microns or higher) and where tight tolerance cutting needs to occur (membrane switches). Galvonometer (Galvo) systems make small adjustments in mirror angles to move the stationary laser beam in different directions within a specific cutting area. Technically advanced Galvo systems use a sealed Co2 laser versus semi-sealed laser sources. The advantages of the Galvo system are speed (100m+ using a single laser head), software advancements that eliminate operator error from occurring and removal of costly tooling expenses incurred using traditional tool-based systems. Galvo systems are now bringing your converting department into the short run, quick turnaround realm that was recently reserved only for digital printers.

Galvo lasers have seen the most significant transformation within the past several years due to software advancements. These advancements can be analyzed in several different ways however the most important seem to be the practical areas that affect a printer’s bottom line.

Tooling Expenses

The main reason people look at laser cutting systems is to remove the daily/weekly/monthly aggrevation and expense of tooling replacement and design. For example, a mid-level printing company spends anywhere from 40,000 to 80,000 Euros per year on tooling. A majority of this replacement tooling is damaged not during the production run rather during changeover. More often than not damage occurs when tools are being placed back into or removed from inventory.

New tooling designs create another significant portion of this annual expenditure. How much time do you spend trying to match die lines to your existing roster of die plates? How often are you restricting your customers by telling them that a certain die design or part outline is already in inventory so this will reduce their expense for a new job? If either case is true then finding a tool-free solution might be the answer. Would there be an advantage to your sales department if they could sell a new job without having to charge the customer for a new die? These are the questions that many printing companies are asking themselves prior to settling on a tool-free converting line.

Scrap Material Savings

Savings do not only come in terms of tooling costs. The consistency achieved with most laser die cutting systems allows users to reduce the amount of scrap during changeover close to 20% annually. For example, many label jobs require a significant amount of kiss cutting. When using either a steel rule die (flat bed die cutting system) or a rotary die cutting system there will be a certain amount of make ready required to shim the die board or magnetic die to keep the kiss cutting consistent. Quality galvo laser systems will produce a 210 micron spot size from the laser source and store jobs that reduce the time need for changeover. The smaller spot size the better cut quality you will achieve because the laser beam (round in shape) is compact and burning the least amount of surface area . Software advancements in laser die cutting control how deep the laser cuts therefore reducing inconsistent depth of cut and unnecessary adjustments on most systems.

Other savings documented by laser cutting users are related to part layout. Annual savings of an additional 15% by nesting parts closer together for maximum throughput and minimal scrap are reported. Traditional tooling layouts require more scrap between parts in order to fit die designs. There are limitations to the amount of metal that can be machined and wrapped for any given layout and laser die cutting reduces these leading edge, trailing edge and gutter requirements.

Operator Software

Advances in software for galvo systems that go unnoticed to many new operators, or first time technology gazers, include speed capabilities and cut quality. These are behind-the-scenes advances that make laser die cutting a legitimate competitor to traditional flat-bed and rotary die cutting systems. The tangible advances in software that relate to operator ease-of-use include optimization and rate estimator tools. Software driven laser die cutting systems on the market today come with optimization tools that take any vector based file (for example, .dxf) and automatically convert the file into the cutting software so that the operator has limited manipulation during job setup. Systems are equipped to automatically split images for optimum throughput speeds and create cutting paths from imported geometries that reduce operator interaction. Basically, the system imports a file from anywhere in the plant and creates a new cutting file. If the material is the same and only the geometries change then you are producing a new part design within minutes. If the material is different but it has been run before then settings have been saved within the laser software and can be recalled quickly so changeover is still within minutes.

Rate estimator tools allow your production department and/or sales personnel the opportunity to price out new jobs in minutes or while on the phone with the prospective customer. It gives you the ability to plug in die lines and laser settings so that production rates can be determined immediately.

Another advantage to laser die cutting is that it allows a printer to print multiple jobs on a single roll of material. Jobs are assigned a specific bar code with a corresponding number and the laser system is equipped with a bar code reader that can change cut configurations immediately. Printers purchasinglaser die cutting technology to coincide with their digital printers are finding that they can take a new job in the morning and have it completed by noon that same day.

Digital Converting Department

Combination sheet fed and roll fed laser die cutting systems are opening up opportunities in converting departments that were not possible in years past. A laser die cutter accepting material from a digital printer with a format of 200mm or 350mm wide also has the ability to run 350mm wide sheets on the same system. Printers have found that this opens up limitless opportunities in your prototype and production departments.

Speed considerations have been subject to debate over the past several years since galvo systems started to make noise in the industry. Single source laser die cutting systems mean you use a single laser source and galvo scan head. There are companies today that are able to reach 100+m per minute using a single scan head. Typically they are using sealed Co2 lasers that are 400 to 600 Watts. Using multiple heads to reach these speeds is acceptable as long as the software within the system is designed to reduce the signs of stitching two images together. This issue can be easily detected during the system qualification process. Most laser die cutting equipment manufacturers encourage capabilities demonstrations to dispel any laser cutting myths that still exist including burn through, rounded corners or image stitching.

Laser cutting systems also offer a wide variety of converting systems including UV coating, lamination, slitting, sheeting, rotary die cutting stations, and much more.

In general, traditional flat bed and rotary die cutting systems continue to make up the majority of converting systems within printing companies. Laser die cutting has overcome early setbacks regarding cut quality and speed by enhancing software to control the laser source. As the printing world moves from traditional printing sources to digital engines the expectations in other areas within printing companies seem to follow. Anytime a solution can reduce operator intervention, increase throughput and eliminate material waste it becomes more obvious that this solution is viable.

Mike Bacon is vice president of sales and marketing for Spartanics, which manufactures laser die cutting systems, steel rule die cutting systems, screen printing lines, automated counters and other equipment. Spartanics is available for technology demonstrations and contract manufacturing services.