> Ideas In Motion > Mechanical Pleated Filter

 
 


Developing filtration products to prevent small particulate matter or micro-organisms from entering the body demands a comprehensive understanding of the dynamics of motion from which ideas on how to inhibit that motion may be developed. Air Safety has that technical understanding and experience to advise as it manufactures both electrostatic and mechanical pleated filters.


Air Safety’s mechanical pleated filters carry hydrophobic properties which provide a complete barrier to viral pathogens under normal clinical conditions. Efficiencies up to 99.99999% are available among Air Safety’s range of mechanical pleated filters. The advantages of an ability to cope with all particle sizes, high efficiency over long periods, increased efficiency over time, and highest possible performance (99.99999% on 24 Hour Test) need to be balanced against the higher cost of production.
Fig 2 Direct Interception: This occurs when a particle passes within half of its diameter of a fibre’s surface and is most effective for particles in the 0.3-1 micron range. The smaller the pore size, the greater the efficiency in interception.

Fig 3 Inertial Impaction:
This results from a directional change of the gas flow. Particles of 1 micron and greater remain on their original course and impact on
the surface of the media as a result of the large mass and inertia.

 Fig 4 Diffusion: Particles of less than 0.3 microns are captured as a result of undergoing considerable brownian movement
> Electrostatic Filters > Significance Of % Removal of Bacteria/Viruses
 

Air Safety’s electrostatic filters utilise a unique patented ‘triboelectrical charge exchange’ between a specially developed blend of polymers to induce a highly stable electrical charge on every individual fibre in the media to more easily trap small particles.

Fig 1 Electrostatic Filter
– 50% of fibres +charged:
50% of fibres –charged.

The advantages of this type of filter are: efficiencies up to 99.9999%; low manufacturing costs; ease of construction.


Number of Organisms Challenging the Filter
Number of Organisms Passing through the Filter
% Efficiency
1 000 000
100 000
90
 
10 000
99
 
1 000
99.9
 
100
99.99
 
23
99.997
 
10
99.999
 
1
99.9999


A 99.99999% filter is 10 times more efficient that 99.9999% and 100 times more efficient than 99.999% and 1000 times more efficient that a filter rated at 99.99%