摘要:
A non-woven fine fibrous/micro fibrous filter material for aerosol filtration and personal safety aids, the fibrous material comprising a styrene/acrylonitrile copolymer and/or polystyrene, dissolved in esters such as ethyl acetate and butyl acetate which are relatively non-toxic. The material may be charged during manufacture with a permanent electret charge. The invention also relates to a method for making a fine fibrous filter material having homogeneous diameter fibres, using relatively low toxicity polymer solutions and by additional processing of the fibres using saturated solvent vapours at the fibre forming process zone.