Fabrics Employing Binder/Top Interchanging Yarn Pairs

Abstract

Multi-layer forming fabric having a paper side warp layer and a machine side warp layer, the fabric comprising at least one set of paper side wefts, at least one set of machine side wefts and at least one pair of interchanging weft yarns, the members of each interchanging weft pair together forming one continuous weft path on the paper side wherein all of the interchanging weft pair members interweaving with at least one paper side warp and in at least one interchanging weft pair interweaving with at least one machine side warp and with at least one paper side warp yarn and the other member interweaving only with at least one paper side warp yarn.

1 - 37 . (canceled) 
   
   
       38 . Multi-layer forming fabric having a paper side warp layer and a machine side warp layer, the fabric comprising:
 at least one set of paper side wefts;   at least one set of machine side wefts; and   at least one pair of interchanging weft yarns, the members of each interchanging weft pair together forming one continuous weft path on the paper side,   wherein all of said interchanging weft pair members interweave with at least one paper side warp and with at least one interchanging weft pair,   one of the members being a binder member interweaving with at least one machine side warp and with at least one paper side warp yarn, and   the other member being a top-member interweaving only with at least one paper side warp yarn.   
   
   
       39 . Multi-layer forming fabric according to  claim 38 , wherein the paper side layer of the fabric comprises only paper side warp yarns and interchanging weft yarn pairs, of which at least one pair comprises one binder member and one top weft member. 
   
   
       40 . Multi-layer forming fabric according to  claim 38 , wherein one of, a binder member or a top member of the binder-top pair provides a stiffening section by remaining inside the fabric for two or more adjacent warp yarns and by being bound on each end of the stiffening section with a warp yarn of the same fabric layer. 
   
   
       41 . Multi-layer forming fabric according to  claim 40 , wherein the length of a top member stiffening section is between 5 and 9 warp pairs. 
   
   
       42 . Multi-layer forming fabric according to  claim 40 , wherein the length of a binder member stiffening section interlacing with machine side warp yarns is between 2 and 4 warp pairs. 
   
   
       43 . Multi-layer forming fabric according to  claim 38 , wherein the binder member of at least one interchanging weft pair per weave repeat interweaves with only one machine side warp yarn. 
   
   
       44 . Multi-layer forming fabric according to  claim 38 , wherein the binder member of at least one interchanging weft pair per weave repeat interweaves with more than one paper side warp yarn. 
   
   
       45 . Multi-layer forming fabric according to  claim 38 , wherein at least one of the interchanging binder-top yarn pairs provides a minimum of 2 segments within each weave repeat. 
   
   
       46 . Multi-layer forming fabric according to  claim 38 , wherein at least 50% of the pairs of interchanging yarns are intrinsic, interchanging binder-top yarn pairs providing a minimum of 2 segments within each weave repeat. 
   
   
       47 . Multi-layer forming fabric according to  claim 46 , wherein all of the interchanging binder-top pairs provide a minimum of 2 segments within each weave repeat. 
   
   
       48 . Multi-layer forming fabric according to  claim 38 , wherein the ratio of paper side to machine side warp yarn diameter is in excess of 0.75. 
   
   
       49 . Multi-layer forming fabric according to  claim 38 , wherein the cover factor of the paper side warp yarns/cm unit width is in excess of 40.0%. 
   
   
       50 . Multi-layer forming fabric according to  claim 48 , wherein the paper side and machine side warp diameters are 0.11 mm paper side and up to 0.15 mm machine side. 
   
   
       51 . Multi-layer forming fabric according to  claim 48 , wherein the paper side and machine side warp diameters are 0.12 mm paper side and up to 0.17 mm machine side. 
   
   
       52 . Multi-layer forming fabric according to  claim 48 , wherein the paper side and machine side warp diameters are 0.13 mm paper side and up to 0.19 mm machine side. 
   
   
       53 . Multi-layer forming fabric according to  claim 48 , wherein the paper side and machine side warp diameters are 0.14 mm paper side and up to 0.19 mm machine side. 
   
   
       54 . Multi-layer forming fabric according to  claim 48 , wherein the paper side and machine side warp diameters are 0.15 mm paper side and up to 0.20 mm machine side. 
   
   
       55 . Multi-layer forming fabric according to  claim 48 , wherein the paper side and machine side warp diameters are 0.16 mm paper side and up to 0.22 mm machine side. 
   
   
       56 . Multi-layer forming fabric according to  claim 49 , wherein the paper side MD yarns/cm unit width when using 0.12 mm paper side MD yarns is in the region of 35 to 40 yarns/cm. 
   
   
       57 . Multi-layer forming fabric according to  claim 49 , wherein the paper side MD yarns/cm unit width when using 0.13 mm paper side MD yarns is in the region of 30 to 35 yarns/cm. 
   
   
       58 . Multi-layer forming fabric according to  claim 49 , wherein the paper side MD yarns/cm unit width when using 0.14 mm paper side MD yarns is in the region of 30 to 35 yarns/cm. 
   
   
       59 . Multi-layer forming fabric according to  claim 49 , wherein the paper side MD yarns/cm unit width when using 0.15 mm paper side MD yarns is in the region of 28 to 33 yarns/cm. 
   
   
       60 . Multi-layer forming fabric according to  claim 49 , wherein the paper side MD yarns/cm unit width when using 0.16 mm paper side MD yarns is in the region of 26 to 33 yarns/cm. 
   
   
       61 . Multi-layer forming fabric according to  claim 38 , wherein the effective paper side to machine side CD ratio is 2:1. 
   
   
       62 . Multi-layer forming fabric according to  claim 38 , wherein each of the members of at least one interchanging weft pair form per segment at least two knuckles over paper side warp yarns. 
   
   
       63 . Multi-layer forming fabric according to  claim 38 , wherein the number of paper side knuckles made by a top member is one of, 2 or 3. 
   
   
       64 . Multi-layer forming fabric according to  claim 38 , wherein the number of paper side knuckles made by a binder member is 2 or 3. 
   
   
       65 . Multi-layer forming fabric according to  claim 38 , wherein for an interchanging weft pair, the ratio of paper side knuckles made by a top member and the paper side knuckles made by a binder member is between 0.5 and 1.5.