Synthetic fibres are measured in "deniers". For example, a 15 denier fibre would weight 15 gms per 9000 metres, and a 3 denier would correspondingly weight 3 gms per 9000 metres. It follows that a 15 denier fibre is heavier & thicker than a 3 denier fibre. When applied to needle felts, a felt produced wholly from 3d fibres would contain approximately 5 times more individual fibres than a felt produced wholly from 15d fibres. The former felt Wood, also have approximately 5 times more number of individual "openings" when compared to the latter, and logically, the 3d fibre felt would have correspondingly smaller size openings. Smaller openings will not permit particles to pass through as easily as a felt made from 15d fibres, and is much more "efficient". Conventional needle felts for dust & gas filtration are generally produced from fibres between 2d to 6 d.

Taking note of this fact, our entire back process was designed to process "micro-fibres" which are fibres below 1 denier (or 1gm per 9000 metres !!!) In comparison to a 3d felt, our felt would offer 3 times more number of open (& correspondingly 1/3 the size of each opening) when compared to a felt produced from 3d fibres. The smallest particulate can be effectively arrested by the judicious use of "micro-fibres" which is the cornerstone of out needle felt technology.