Choosing a LGAC removal system that’s good for your pocket book and the environment.

Earlier we talked about Laser Generated Airborne Contaminants or (LGACs); how they can affect your workers, your equipment and which LGAC removal system is right for you. Other than its precision one of the main reasons you chose laser processing equipment was its long-term cost benefits. Instead of conventional methods to process materials there are few or no consumables such as drills, milling cutters, saws, etc. Therefore, in choosing an LGAC removal system it is important that any purification system does not nullify this benefit by passing along excessive filter costs to the user. One method the Purex system offers of prolonging the life of a main filter is to use a pre-filter to remove larger particles (=1um) from the airstream before they enter the main filter. These are come in different forms, ranging from pads to bags to a patented Labyrinth design that offers around 10 times the life of a normal pre-filter. Pre-filters are made from a variety of filter media, and it is vitally important that the correct type is specified by the supplier – otherwise the life of the main filter will be significantly reduced. This is especially true if the material that is processed releases oily or sticky particles.

To better understand the need for the LGAC system it helps to understand what happens during laser processing and how it can affect your workers?

When a laser beam is applied to the surface of a material; high temperatures that are generated, cause the air near to the contact point to expand generally back in the direction of the lens. The laser beam causes incineration, vaporization, melting and softening of the material. Rapidly expanding gases pickup and carry the removable particles and droplets at relatively high velocities away from the product material. The contaminants released consist of a wide variety of gases, in some cases noxious such as benzene or phosgene. They also consist of products of combustion including possible oxides of the base material. Stainless steel, for example, releases chromium and nickel, which can cause chronic toxicological effects such as liver/kidney disease and cancer.

There are several things that are different about laser cutting styrene as opposed to many other materials. Is it safe to laser cut styrene? Safe, yes, but it is a little tricky.  Styrene tends to cut with rolled edges so the thinner the better for clean cuts. You can do better with less power, more speed, and two passes. Another option for straight cuts is to have the laser score it then break out the pieces. What about issues with poisonous fumes? Styrene doesn't contain PVC, so no worries there with fumes. As long as your laser has a full filter system that extracts outdoors, it should not be an issue. However, cutting anything that has chlorine in it like PVC generates chlorine gas, which despite your filtration system, might affect your lungs. The thing with cutting PVC or other plastics with chlorine is that not only is it bad for your lungs, but it is bad for your equipment. It can deteriorate your optics, corrode the metal, and otherwise foul your electronics.