20 Jan Fume Extraction and Filtration Systems for Laser Cutting
Sources of Fumes when Laser Cutting
Although laser machines themselves don’t produce fumes during operation, the material being processed usually does and it’s essential to have these fumes removed from the working area and either out of the building or into a self-contained fume filter.
We’re often asked about the differences between our standard extraction to atmosphere and the option for a fume filter system. Let’s take a closer look at the options available for dealing with the fumes emitted by cutting acrylic, one of the most common materials processed on a laser machine.
Laser cutting acrylic thermally decomposes the material and produces fumes which are 90% volatiles (extremely hazardous), the remaining 10% are sub-micron particulates. See Alen Corp’s article for more detail.
Preventing Fumes from Causing Harm
As standard, our machines are supplied with an extraction fan unit and two lengths of flexible hosing. One hose is installed between the laser machine cabinet and the extraction fan. The other hose is installed between the extraction fan and the interface to the outside world, typically a hole in an outside wall together with a louvred or flapped cover plate on the outside to prevent rain and moisture entering the extraction system.
When to use a Fume Extraction System
If the layout of the room or building is not suitable for extraction to atmosphere, it is worth considering a self-contained fume filter system. Instead of ventilating the laser fumes to the outside world, a fume filter typically uses a combination of a HEPA (High Efficiency Particulate Air) pre-filter and a combined filter which contains activated charcoal. The HEPA filter captures the airborne particles in the extracted air and the charcoal filter removes the aroma. The result is extracted air which is safe to circulate within the room. For this reason we use fume filters to demonstrate laser machines at exhibitions and they are often selected for larger premises such as schools and universities where it may not be possible to extract through an outside wall.
BOFA Filter Systems
For fume extraction into a filter system, HPC Laser work directly with the global lead in fume extraction technology, BOFA International. Our working relationship with BOFA means we supply fume extraction filter systems and filter replacements for an excellent price.
Bofa filter cartridges need to be changed once they are saturated. Depending upon the exact model of filter unit, an alert would usually be produced once the pre-filter was sufficiently full to affect airflow. Once the carbon filter is saturated an increase in fume aroma will be noticed, indicating that it is time for the filter to be changed. Some models of BOFA fume filters have an additional VOC (Volatile Organic Compound) sensor that enables an alert to notify when it is time for the carbon filter to be changed.
The time taken for the filter cartridges to require changing varies significantly depending upon machine use and the particular materials that are being processed. For example, MDF produces a high concentration of dust and airborne particles which will fill the pre-filter cartridge much faster than acrylics which are typically low on airborne particles and have much higher levels of volatile organic compounds which will saturate the carbon filter.
Some materials such as HPC’s laser plywood is particularly well suited to laser cutting and produces excellent results with a minimum of smoke and fumes.
Materials to Avoid
You can generally cut most types of plastic with a laser machine without any issues, providing you don’t cut PVC. This material emits chlorine when heated, a very hazardous substance that is likely to damage components within your machine, and even worse, the health of those in the immediate vicinity. If you are in any doubt about the suitability of any materials to be cut with a laser machine please always contact the material manufacturer for advice.
Packages including bespoke extraction systems are available.
For more information, please contact us:
Tel: 01422 310800
Live Chat: www.hpclaser.co.uk