Method for producing a strengthened nonwoven from at least partly microfine endless fibers and nonwoven according to this method

Abstract

A strengthened nonwoven is made at least in part of spun microfibers that are strengthened by hydrodynamic needling, alone or together with other fibers such as also staple fibers and/or endless fibers. The microfibers are spun from a polymer melt of only one certain polymer from a plurality of spinning apertures, and the spun filaments are drawn by gas streams accelerated to high velocity by an accelerating nozzle such as a Laval nozzle and, due to further production conditions, each fiber receives before solidification an internal hydrostatic pressure that is higher than the ambient gas pressure so that each fiber cracks in the longitudinal direction and splits up into a plurality of fine endless filaments.

1 . Strengthened nonwoven consisting at least in part of microfibers 
 a) that are spun from a polymer melt of only one certain polymer from a plurality of spinning apertures and the spun filaments are drawn by gas streams accelerated to high velocity by an accelerating nozzle such as a Laval nozzle and, due to further production conditions, each fiber receives before solidification an internal hydrostatic pressure that is higher than the ambient gas pressure so that each fiber cracks in the longitudinal direction and splits up into a plurality of fine endless filaments    b) and are strengthened by hydrodynamic needling, alone or together with other fibers such as also staple fibers and/or endless fibers.    
   
   
       2 . Nonwoven according to  claim 1  wherein the microfibers are laid onto a support ply made of more-stable chemical fibers and serve as a parting ply for a wood pulp ply laid onto the microfibers.