Nonwoven lap formed of very fine continuous filaments

A controlled direct spinning process for producing a nonwoven lap of continuous filaments having a density of 5 g/m.sup.2 to 600 g/m.sup.2 and comprised of composite filaments separable in the direction of their length, said composite filaments having a filament number between 0.3 dTex and 10 dTex, and are each formed of at least three elementary filaments of at least two different materials and comprising among them at least one plane of separation or cleavage, each elementary filament having a filament number between 0.005 dTex and 2 dTex, wherein the ratio between the cross-sectional area of each elementary filament to the total cross-sectional area of the unitary filament is between 0.5% and 90%, said process comprising the steps of:

• extrusion/spinning, drawing/cooling and napping, wherein the lap is subjected, simultaneously or successively, to operations of bonding and consolidation and the composite filaments are at least partially separated into their elementary filaments during the course of said operations of bonding and consolidation, wherein cohesion and mechanical resistance of the nonwoven lap are increased by an operation selected from the elementary filaments being bound by thermobonding of one or more of the elementary filaments formed of a polymer material with a lower melting point, by calendering with a smooth or engraved hot roller, by passage through a hot-air tunnel, by passage over a perforated hot-air cylinder, by the application of a binding agent contained in a dispersion or solution, or in the form of a powder;
• and combinations thereof.