Extremely fine polyphenylene sulphide fibres

Fibres, fibre webs or fibre aggregates made of polyphenylene sulphide (PPS), or of mixtures of PPS with polybutylene terephthalate which are obtained by further processing the polymer melt streams emerging from a spinning nozzle having at least one hole 0.05 mm to 2 mm in diameter, the fibres having an average fibre diameter of <6 .mu.m and having been produced by subjecting the polymer melt streams to drawing out and cooling to below the melt temperature by extruding them into a gaseous medium which flows essentially parallel to the melt streams and which attains sonic or supersonic speed along a zone of 2 mm to 100 mm, the melt streams having been additionally drawn out by the action of a static pressure gradient acting on the melt streams along a zone of 1 mm to 30 mm downstream of the exit openings, this simultaneous deformation and cooling giving rise to amorphous fine or extremely fine fibres of finite length which are deposited to form a fibre web or fibre aggregate.