By Cassandra Balentine
Part 1 of 2
Laser cutting provides an alternative to traditional router knives and oscillating tools. Laser systems offer a clean finish and are compatible with a versatile range of media, including both flexible and rigid materials.
Gas lasers, also known as CO2 lasers, are popular solutions suited for cutting and etching a variety of materials such as acrylic, film, foil, glass, leather, paper, plastic, and wood. Fiber and crystal laser cutters are also available, but are generally limited to metals and plastics.
Flexibility and precision cutting stand out as the two primary benefits of these systems, which are used in a variety of manufacturing settings, including sign and display.
“Laser cutting is especially well suited for digitally printed wide format graphics,” says Steve Aranoff, VP sales and marketing, MCT Digital. He explains that laser cutting provides a robust, non-contact method that eliminates tool wear and pressure on system mechanics.
Laser cutters offer flexibility in the form of substrate compatibility and the ability to make changes without tooling modifications.
Robert W. Boyes, senior product line manager, laser machine tools, Coherent, Inc., says most product design and process changes can be accomplished with a simple file change. “Layers within a job file can enable multiple processes within a part—including engraving, kiss cutting for labels, and cutting,” he says.
Derek Kern, president of sales, Kern Laser Systems, explains that the non-contact process eliminates the chance for scuffing and bumping of material that might cause misalignment.
Aranoff shares that for fabric cutting, the lack of contact means the fabric won’t bunch up and its edges will seal as if cut by a hot knife. “Compared to such a manual method, it is much cleaner and faster, saving between eight and 12 manual cutters per shift. It also eliminates the need for sewing or providing fabric to the sewing department in a more orderly fashion,” he explains.
In addition to fabric, Aranoff suggests laser systems as advantageous in cutting acrylic with flame polished edges and kiss cutting non-PVC materials, widening the cut kerf and ensuring that the kiss cut is perfectly through all around the graphic. He adds that vector-based engraving is also possible.
Precision is another benefit. “Laser systems offer precise cutting results,” says James Stanaway, director of marketing, Epilog Laser. For instance, Epilog provides systems designed to cut through up to .75 inches of hardwood and acrylic resulting in flame-polished edges, he explains.
Joan Kang, product manager, GCC, notes that laser cutting with a small spot size can handle intricate and detailed cutting compared to conventional router knives with high-quality results. “A thermal laser beam will melt the edge of materials. The surface looks very clean. There will be micro cracks or rough edges when using a knife to do the processing.”
Many laser cutting solutions also incorporate engraving capabilities. “Unlike bulkier equipment, the laser can tackle both cutting and engraving applications with amazing detail and control,” says Stanaway.
Boyes adds that CO2 lasers can engrave and cut both organic and metal substrates with high-quality results. “This allows the manufacturer to have primary product capabilities but also expand their capabilities without adding additional equipment.”
While there are many advantages to laser cutting, limitations must also be considered.
“Lasers will have trouble cutting metal and plastic that are sandwiched together,” admits Kern. “To cut metal, you typically use a heat assist such as oxygen. The acrylic layer prefers to be cut with shop air. The oxygen assist gas will burn out or leave a less-than-perfect edge quality in this case,” he explains.
Boyes says material handling can sometimes be a concern for wide format substrates. “This can slow the process down if not planned in advance. There are a small number of materials that are not realistic for conventional laser cutting,” he adds.
Stanaway warns that while many materials are laser friendly, PVC is not. “When laser cut or engraved, PVC releases a corrosive gas that is harmful to both the machine and operator.”
Aranoff adds that lasers are not suitable for fabrics with a heavy cotton content.
Kern suggests considering the substrate you are handling to determine whether or not laser cutting is the best finishing method. He offers the example of acrylic. “Most digital cutters would leave an edge quality that would need to be flame polished after the cutting process. The laser will naturally cut and leave a glossy fire-polished edge that requires no secondary processing.”
Kang adds that when laser cutting printed output, different laser system configurations might be required. For example, an optional camera system and printed registration marks may improve the process for contour cutting printed objects. While for cutting aluminum composite board, normal CO2 laser cutting systems may not do the trick, instead a high-power CO2 laser with add-ons like special cutting heads and oxygen assistance are a better option.
Laser cutters provide many advantages to print providers looking for a new way to cut, especially when precision is a top priority.
“There is always a proper machine to use for your application, but lasers are typically more versatile and ready to tackle a wide range of materials,” says Kern.
Part two of this article provides a roundup of laser cutters currently on the market.
Oct2015, Digital Output DOLC1510