Electrostatic filtration media are said to offer the following benefits:
• more efficient filtration
• lower pressure drops
• increased capacity to filter out fine particles (< 1 μm)
According to Texel, mechanical filtration is less effective at stopping particles less than one micron in size because the fibers, whether natural or synthetic, have a diameter in the order of 20 μm (coarse fibers).
Electrostatic filtration captures particles using Coulombic attraction or repulsion and dielectrophoretic forces. These two mechanisms are effective against particles varying in size from 0.05 µm to 5 µm and are described as follows:
• Coulombic attraction or repulsion: This mechanism is the result of electric charges that are on the filter and on the particle to be filtered. A particle that is therefore charged negatively will be attracted to the positively charged area of the filter media.
• Dielectrophoretic forces: A dipole is led to a neutral particle when it enters the electrical field of an electrostatic filter. This dipole will then attract the particle towards the surface of the filtering media that will capture it.
Texel’s Tribo filter line covers a full range of media aimed at a diverse range of markets such as respirators, cleanrooms, furnace filters, vacuum cleaners and cabin air filters. Texel can also superimpose layers to meet a customer’s performance requirement.