Method for making three-dimensional macroscopically-expanded webs having improved functional surfaces

A process for forming a three-dimensional macroscopically-expanded, fluid pervious web having an improved functional surface, said web being comprised of a sheet of polymeric material, said sheet having a first surface and a second surface, said process comprising the steps of:

• (a) printing a plurality of discrete deposits of a water resistant resinous material on said first surface of said sheet via a screen printing roll, said resinous material having a pre-determined open time;
• (b) drawing said deposits of said resinous material upwardly from said first surface of said sheet via said screen printing roll to form corresponding fibrils during said open time;
• (c) curing said resinous material via an air cooling system;
• (d) feeding said sheet onto a forming structure having opposed surfaces such that said second surface of said sheet is in contact with said forming structure, said forming structure exhibiting a multiplicity of apertures which place the opposed surfaces of said forming structure in fluid communication with one another, and
• (e) applying a fluid pressure differential comprising a high pressure jet of liquid across the thickness of said sheet, said fluid pressure differential being sufficiently great to cause said sheet to rupture in those areas coinciding with said apertures in said forming structure and to conform with said forming structure while substantially maintaining the orientation of hid fibrils, wherein said fluid pressure differential causes said sheet to be drawn downwardly into said apertures, such that capillaries are formed in said sheet, said capillaries containing a plurality of fibrils extending therein.

A process for forming a three-dimensional, macroscopically-expanded, fluid pervious web having an improved functional surface, said web being comprised of a sheet of polyethylene film, said sheet having a first surface and a second surface, said process comprising the steps of:

• (a) printing a plurality of discrete deposits of a water resistant resinous material on said first surface of said sheet via a screen printing roll, said resinous material having a pre-determined open time, said resinous material comprising a silicone resin;
• (b) drawing said deposits of said resinous material upwardly from said first surface of said sheet via said screen printing roll to form corresponding fibrils during said open time;
• (c) curing said resinous material via an air cooling system;
• (d) feeding said sheet onto a forming structure having opposed surfaces such that said second surface of said sheet is in contact with said forming structure, said forming structure exhibiting a multiplicity of apertures which place the opposed surfaces of said forming structure in fluid communication with one another;
• and
• (e) applying a fluid pressure differential comprising a high pressure jet of water across the thickness of said sheet, said fluid pressure differential being sufficiently great to cause said sheet to rupture in those areas coinciding with said apertures in said forming structure and to conform with said forming structure while substantially maintaining the orientation of said fibrils.