Filter for room ventilation air, particularly for motor vehicles, employs self supporting synthetic fibre fleece with dimpled or corrugated surface finish

摘要

Dimpled or crimped surface filtration element is produced from micro-spun bonded, melt-blown or similarly generated synthetic fibre fleece which is pliable and yet self -supporting, and comprises fibre of average diameter greater than 3 micron mixed with reinforcing fibres of 8-30 micron diameter. Independent claims are included for: a process in which a filtration medium is formed on a dimpled or corrugated fibre collection surface to impart this configuration , or the mirror image, on the fibre web; and, a process in which such a filtration medium is finished by coating with nano fibres e.g. by electrostatic means.