Exhaust Systems For Laser Engravers "Suck"
These days, as laser engraving becomes more and more popular, the need for proper ventilation and fume removal is often overlooked. There are three basic methods; direct ventilation out of the building, tapping into a large air handling system, or a stand-alone filtered system. There are advantages and disadvantages to each which will be addressed. It is important to note that most flatbed lasers are operated in a retail environment, relatively small shops or are even home based so not every method of ventilation is applicable.
Laser engraving is very versatile and a wide variety of materials can be processed with attractive results. Because of the diversity of the substrates it is imperative that dust, debris and fumes be efficiently removed from the laser enclosure. The need to ventilate is not unimportant. Considerations include safety, potential damage to the laser and work environment.
Safety for the operator and other personnel in the shop should be paramount for any employer. Lasing is a thermal process and as such the material is burned, melted and vaporized. Some plastics are even toxic when they are heated and the fumes can be harmful when inhaled. To address this all lasers come equipped with a fume removal port that allows external connections.
Air is "pulled" through this port by the vacuum unit and away from the lasing area. What happens to that particle laden air is what differentiates the three ventilation methods.
The simplest method is to use a blower system that draws the air through a hose which is then ported outside the building. This is certainly functional but typically does not handle odor or the fumes very well and often there is a strong residual smell in the work area. In addition, certain parts of the country have EPA (Environmental Protection Agency) rules that prohibit pumping toxic elements into the air. Blower motors tend to operate at a fairly high decibel level so they can be quite loud. The blower motors themselves are inexpensive, but sometimes there are modifications required to the building itself that can drive the overall costs to install up.
In industrial environments there are sometimes existing air handlers that can be tapped into via the laser exhaust port. These very large devices are filtered such that the air they expel in to atmosphere has been "scrubbed" and is not toxic. In most cases they comply with the local EPA restrictions and are totally safe. However these are physically large, expensive units that are designed for use in manufacturing plants and are overkill if purchased solely to operate that standard laser engraving system. If such a system exists in your building by all means explore this as an alternative for your ventilation needs, but make sure that the system has the capacity needed for the laser when venting other equipment in the facility at 100% volume.
The third alternative is a self contained, multi-stage filtered device. As with the others, it attaches to the port on the laser but then draws the air through a series of filters that serve to remove large particles, gasses and odors. The air that is vented from the unit is usually 99% odor free and is safe to inhale. These devices are relatively small, very quiet and are portable. The filters are consumable items and have various operating durations based on usage and the particulate being filtered.
The filter system consists of a large particle filter/or catch bag, a HEPA filter and either an active chemical filter or activated charcoal reservoir. All of the filter elements can be replaced by the user with very little effort. Unlike the other configurations which are hard plumbed to the laser, the stand-alone units are mounted on wheels and can be easily relocated within the shop at the operator's convenience. This makes them the preferred solution for smaller shops and home based businesses.
There are a number of vendors such as Quatro, TBH, Purex and others. If this seems to the best alternative for you take the time to evaluate the systems including the Db level and the consumable costs.
Protecting the laser is also a consideration. Some plastics produce caustic and molten particulate that can infiltrate the moving parts of the laser gantry. In some instances, this can cause rust or non-typical wear on components which can affect the life of the motors, belts, screws and consequently can deteriorate the performance and output of the machine. Out gassing and smoke caused by lasing plastic, wood or coated materials can adhere to the optical components of the unit. Dirty mirrors or lenses lead to low output power or back reflection issues that can result in damage to the system. All adequately sized fume removal systems should have the air volume capabilities to protect the mechanical elements and optical components from these air born particles. All laser manufacturers should be able to provide the CFM requirements for their laser models which can then be used to size the proper exhaust unit.
Having a comfortable work environment is a goal of most shop owners. Managing the odors caused by processing wood, leather, plastics or rubber is part of the effort to keep the employees happy and productive. If you have ever had to smell some of the materials mentioned burning it is obvious how unpleasant it can be. If you take this one step further and consider the customers in the shop you can see how managing the fumes and odors should be a priority. Some vendors operate lasers in malls or other retail locations so courtesy for the storefront next to yours, should not be discounted. The last thing you want to do is to drive your customers out of the shop due to a very manageable situation.
Whether you have already purchased a laser engraver or you are investigating adding one to your shop, do your due diligence when selecting a ventilation method also. The laser is an investment in your business so maximize your return by choosing the proper exhaust system that will extend the life of the machine and provide a safe comfortable working environment for you and your employees.
I'll be happy to provide advice should anyone wish to contact me.
