Understanding lasers (II)
Lasers, due to their unique blend of speed
and versatility are currently used in a variety of industries to engrave and
cut a variety of materials. Here are the most popular:
Since lasers were first used for engraving, acrylic has been a favorite. Combining the beauty of glass with the durability of plastic makes it a viable option for many applications including awards, executive desk items, signage, display cases, and frames. Acrylic is manufactured in a wide range of colors, shapes and products. Acrylic can also be cut using a laser. With a 25 watt system you can cut up to 1/8 thick or thinner pieces. ¼ pieces will cut through with a 50 watt system and for ½ consider 100 watts of power. Popular applications for cut acrylic include letters and a variety of shapes.
Many engravers have discovered that a laser can produce a light surface etch on glass that is attractive for many applications. Wine bottles, stemware, vases and picture frame glass can all be laser engraved. When engraving on glass, however, be careful. Some glass, that which has a high lead content, may be prone to shattering and/or cracking. It is always best to experiment and always ask for extra pieces when possible.
Hard surfaced materials such as Corian can be laser engraved and are also used for a range of applications including plaques, awards, and signage. Such material engraves well and is also extremely durable. Such materials do require color filling because of the lack of contrast.
Leather, when laser engraved, can produce some unique and interesting effects. Items such as belts, hats, watch bands, etc. are some of the many applications for laser engraved leather. When choosing leather for laser engraving, be aware that leather products tend to vary. Therefore, laser engraving results will also vary. It is important to experiment first and to stick with products that laser engrave well. Leather also tends to put off offensive odors when exposed to the heat of a laser. Therefore, a good working exhaust system is essential to removing the vaporized material and fumes to the outside.
Marble is another great choice for laser engravers. Its' natural beauty makes it appealing for both awards and gift ideas. When choosing marble for laser engraving, look for pieces that allow for contrast. Marble is another material that also lends itself well to the addition of color.
While engraving on bare metals has always been a challenge when using a CO2 laser engraving system, coated or painted metals do engrave well using this type of laser. In fact, today's laserable coated metals are attractive to the laser engraver because they are polished and lacquered prior to applying the outer layer of paint. This results in engraving that is crisp and ready immediately after engraving. The lacquering also prevents the engraved area(s) from oxidizing. Today's laser engravable coated metals come in a wide range of metals, shapes, colors, and designs that can be used for a wide range of applications.
Additionally, there is now an option for engraving on some bare metals. Dmc2, (formerly Cerdec ) offers a spray, which when applied to certain bare metals, prior to engraving, will fuse with the metal and allow the laser beam to produce a dark permanent mark. While this does not work on all applications, it does allow some metal products to be engraved with a CO2 laser.
There are a variety of plastics that both laser engrave and laser cut with great results. Manufacturers of plastic materials have created a new generation of laserable plastics with thin outer layers that are easily removed by laser. This has resulted in less melting, scorching, and discoloration associated with earlier laser engraving of plastic materials. Today's laser engravable plastics come in a range of colors and patterns and are used for signage, plaques, nametags, and ad specialty items.
Laser engraved wood still produces results that are popular for a variety of purposes including trophy bases, desk accessories, plaques, awards, and bats. Make sure you look for woods that provide contrast when engraved. Favorites include oak, walnut, maple, cherry, and mahogany. There are also a variety of exotic woods available, too. When purchasing wooden products for laser engraving, look for products that are sold as laser engravable. This will ensure that any stains, bleaches, oils, etc. used in finishing the wood will not cause adverse reactions when exposed to the heat of a laser.
There are a also a variety of other materials out there that are laser friendly. This includes vinyls, rubber stamp material, matboard, paper, synthetic marbles and stones, synthetic woods, cork, and gasket materials. When shopping for products, try to stick with products sold as laser engravable. Not only will this assure that the material will engrave or cut favorably, but the material manufacturer may also provide you with recommended settings and other tips to use when laser processing their products.
Laser processing lends itself to a range of versatile materials, with more constantly being developed. Dont forget to always experiment for best results and use trade shows, trade journals, and online searches to keep up with new possibilities. This way, you can continue to provide your customers with the latest materials that the industry has to offer.
By Diane C. Bosworth