Substantially closed fabric made by compressive redistribution of the filaments of at least some yarns of an open mesh fabric

Claim 1

A process for making an essentially closed fabric which comprises: providing an open mesh fabric having an open area of less than 70% of the area of the fabric, the open mesh fabric being of a type comprising at least one layer of warp yarns and at least one layer of fill yarns, said at least one layer of warp yarns constituting one group of yarns, said at least one layer of fill yarns constituting a second group of yarns, said warp and fill yarns intersecting one another at an angle, at least the yarns of one of said two groups of yarns being composed of continuous filaments having at least twenty filaments per yarn, at least said yarns of said one group also having not more than one turn per inch, the denier per inch of at least said one group of yarns being at least four thousand, said yarns being coated with at least 5% based on the weight of the yarns after having been coated of a thermoplastic material having a softening point which is lower than the softening point of said filaments, said thermoplastic material being in a sufficiently soft condition that said filaments are capable of spreading out when subjected to compression; applying sufficient pressure to said open mesh fabric to cause said filaments to spread out to close the openings in said open mesh fabric to the extent that the open area of said open mesh fabric is reduced by at least 50% with all of said yarns lying in substantially a single layer, said pressure being applied by passing said open mesh fabric through the nip between two rotating rolls, one of said rolls being heated to a surface temperature at said nip above said softening point of said thermoplastic material but less than the softening point of said filaments and the other of said rolls having a surface temperature less than the softening point of said thermoplastic material; and maintaining said filaments in their spread out position while permitting said thermoplastic material to set by withdrawing the fabric from said nip while maintaining said fabric in tension and in contact with the surface of said other roll immediately after said fabric has passed through said nip for a time at least sufficient for said thermoplastic material to set to a point where it maintains said filaments in spread out position, whereby an essentially closed fabric is made by compressively redistributing said filaments of at least said one group of yarns of said open mesh fabric.