Process for the preparation of a microfibrous suede-like nonwoven fabric

A process for the preparation of a microfibrous non-woven fabric, comprising the steps of:

• a) preparing a bicomponent fibre of an island-sea type, in which the sea component is a polymer that is removable in hot water or in an aqueous alkaline solution;
• b) preparing a felt by needle-punching the bicomponent fibre of the island-sea type;
• c) performing hot impregnation of said felt with an aqueous solution of polyvinyl alcohol (PVA) having a degree of saponification of at least 94%;
• d) removing the sea component from the felt impregnated with PVA as obtained in step c), by contact of the felt with an aqueous basic solution of an alkaline or alkaline earth hydroxide, thereby obtaining a microfibrous intermediate product;
• e) adding to the microfibrous intermediate product of step d) acidic water which reacts with the alkaline or alkaline earth hydroxide of the d) to form a layer of salt near a surface of said microfibrous intermediate product;
• f) leaving said layer of salt on a surface of said microfibrous intermediate product;
• g) performing cold impregnation of the microfibrous intermediate product specified in step e) with a polyurethane (PU) dispersed in water containing additives for adjusting viscosity, wherein said layer of salt near the surface enables the distribution of PU;
• h) fixing the PU to the microfibrous intermediate product by means of coagulation of the PU dispersion and subsequent drying;
• i) removing the PVA added at step c), the salt formed at step e) and the additive added at step g);
• and
• j) subjecting the material thus obtained in step i) to cutting, buffing, on one or both sides, and dyeing.