Interested in filter life? So are lots of visitors to our website and participants of our free BOFA Academy modules. Here are some of the most common questions asked – and answers from our knowledgeable technical team.
How do manufacturers select the appropriate extractor size to optimise filter life as well as extraction flowrate?
Selecting an extractor best suited to your process is essential as sometimes purchasing a smaller, less expensive extractor on a high throughput laser coding line, or cutting / engraving application, can be false economy.
Many factors need to be taken into account and it’s advisable to contact BOFA engineers at an early stage. They can help select the most appropriate system for any given process by determining the type, volume, size, shape and velocity of particles being emitted.
Factors will also include whether a process is enclosed or not, the duration of the process (for example 24/7 operation) and whether there are thermal risks associated with higher temperatures.
The information gathered by BOFA engineers, together with data-driven airflow analyses and control parameters, will help define the optimal filtration technology.
BOFA systems also incorporate filtration saturation sensors and many of our units offer remote diagnostics, so monitoring filter performance and lifecycle can be undertaken in real-time. This enables filter exchanges to be scheduled as part of maintenance routines to minimise downtime.
Never be tempted to replace BOFA approved filters with alternatives. BOFA filters have been purpose designed to work with specified extractors and take account of many factors, such as face velocity, pressure drop, residency time and structural integrity.
Installing non-genuine replacements could impair filter efficiency or lead to rupture, with the potential for downtime and negative impact on product quality. For more information about the importance of using genuine filters, please request your free copy of our guide.
How do manufacturers optimise filter performance on acrylic cutting?
In the case of laser cutting or engraving of acrylic, it can sometimes require the extractor to be run at slower speeds, as acrylic fume (in an opposite way to most other plastics) contains about 80-90% gaseous chemical compounds, and very little solid particulate. So, a slower pump speed gives a longer residence time for the fume in the carbon filter, enabling it to work more efficiently and there should be less tripping of a volatile organic compound (VOC) alarm, which may otherwise be incorrectly indicating a saturated filter.
How to select the appropriate pre-filter for MDF cutting?
Unlike acrylic, MDF cutting often generates large amounts of particulate that can occasionally block pre-filters. BOFA advises switching the standard F8 pre-filter, which has an efficiency rate of around 90 – 95% at particle sizes of 1-3 microns, to an F9 pre-filter, which has an efficiency of >95% at particle sizes of 0.5 – 1 micron; this can sometimes improve the situation.
Alternatively, we can provide multi-layer bag filter options, or standalone additional in-line filters for MDF applications.
To find out more about filters, go to the FAQs section on our website: https://www.donaldsonbofa.com/en/support/faqs/
