Sign & Digital Graphics

Start Here October '18

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79 S T A R T H E R E 2 0 1 8 internal fan to draw out the smoke from the laser and three types of filter elements to clean the air. The extra up-front cost of a filtration system will be amortized over time when compared to the expense of a duct-based exhaust fan system. If mobility is part of your business plan, then you defi- nitely require one of these filtration systems so you can laser engrave on the road. Laser Materials 101 Let's talk about what really makes our laser engraving business: the laser materials. You should know that not all materials are laser friendly. The laser engraving process uses the focused heat energy from a laser to vaporize, melt, and burn materials. It is this process that generates the smoke and outgassing from the substrates. Some materials can release or out-gas toxic or caustic fumes as part of the laser engraving process. Avoid these materials. On the materials-to-avoid list are any that contain PVC or Poly Vinyl Chloride. As soon as the PVC material is engraved, a highly corrosive smoke is released. Not only is this smoke bad to breathe, it is also damaging to your laser system. PVC materi- als are so harmful to the laser system that all manufacturers void the warranty if damage from PVC fumes is present. The downside is that it is hard to tell if a product contains PVC, but there are some test strips and other tests that show the corrosive nature of the fumes right away. Another common product that is not laser friendly is any type of polycarbon- ate product that might be under the trade name Lexan. Out-gassing for polycarbon- ate is a little easier to see because a rich yellow smoke is emitted during laser pro- cessing. Again, more corrosive fumes, so stay away from polycarbonate products. Which materials work best with a CO 2 laser and are laser safe? Wood, anodized and coated metals, glass, acrylic, engrav- ing plastic sheet, granite, stone, leather, Corian, paper, cardboard, rubber, and more. You will find that there is a differ- ence between products available at a home center and products available from a laser materials supplier. For instance, not all wood is created equal and some woods engrave better than others. When it comes to which materials work best for laser engraving, it can be best summed up with creating contrast. Light-colored woods like alder are ideal because they laser engrave a dark brown. Engraving plastic sheet is another good example that offers high-contrast laser engraving when the top color of the plastic sheet is ablated by the laser to reveal the color layer underneath. Asian sourcing has become popular among suppliers of laserable materials for ENGRAVING

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