Polymethyl methacrylate, more commonly called PMMA or acrylic, is highly resistant to abrasion, weathering, and discoloration. PMMA is crystal clear and actually transmits more light than does glass. As a film, PMMA is often used as a laminated protective covering for other plastic materials and products.

In this laser cutting application, we were asked to trim oversized PMMA-based templates to exacting final dimensions. The templates were produced by screen-printing the image of three complete parts on sheets of 312-micron (0.0125") thick acrylic film covered with a protective backing. Our cutting setup consisted of a Synrad CO₂ laser and an FH Series marking head equipped with a 125 mm lens, which provides a 180-micron (0.007") spot with a 3 mm (0.118") depth of focus.

We imported the full-size CAD template into our WinMark Pro laser marking software using a Vector Import Scale property setting of "One-to-One" (under the Tools menu, go to General Settings, and then click the Object Defaults tab). On the Marking tab, we set a Power value corresponding to 50 watts, a Velocity of 216 millimeters per second (8.5 inches/second), and a Resolution of 150. To further reduce cycle times, we increased Off Vector Velocity (non-marking scan speed) to 3810 mm/sec (150 in/sec).The cycle time required to cut the outer shape and the inner keypad area is 1.84 seconds per part, which is over three times faster than the customer's current mechanical cutting method.

Our Applications News features the latest CO₂ laser applications direct from Synrad's extensive Applications Lab. The bi-weekly News now includes current news and product information from Synrad, as well as quick links to frequently requested sites. It is published every other Thursday.

As always, the most up-to-date news and information from Synrad can be found on our homepage at www.synrad.com.