Patent ID: 6581645
Filing Date: 2003-06-24
Classification: D21F

Abstract:
A composite forming fabric comprising in combination a paper side layer having a paper side surface, a machine side layer, and paper side layer intrinsic warp binder yarns which bind together the paper side layer and the machine side layer, wherein:(i) the paper side layer and the machine side layer each comprise warp yarns and weft yarns woven together in a repeating pattern, and the paper side layer and the machine side layer together are woven in at least 6 sheds; (ii) in the paper side layer all of the warp yarns comprise pairs of intrinsic warp binder yarns; (iii) in the paper side surface of the paper side layer the repeating pattern provides a warp yarn path in which the paper side layer warp yarn floats over 1, 2 or 3 consecutive paper side layer weft yarns; (iv) each of the pairs of intrinsic warp binder yarns occupy the unbroken warp path in the paper side layer; (v) the ratio of paper side layer weft yarns to machine side layer weft yarns is chosen from 1:1, 2:1, 3:2, and 3:1; and (vi) the ratio of paper side layer warp yarns to machine side layer warp yarns is chosen from 1:1 to 3:1; and wherein the pairs of intrinsic warp binder yarns comprising all of the paper side layer warp yarns are woven such that: (a) in a first segment of the unbroken warp path: (1) the first member of the pair interweaves with a first group of paper side layer wefts to occupy a first part of the unbroken warp path in the paper side surface of the paper side layer; (2) the first member of the pair floats over 1, 2 or 3 consecutive paper side layer weft yarns; and (3) the second member of the pair interlaces with one weft yarn in the machine side layer beside a machine side layer warp yarn that interlaces with the same machine side layer weft yarn; (b) in a second segment of the unbroken warp path: (1) the second member of the pair interweaves with a second group of paper side layer wefts to occupy a second part of the unbroken warp path in the paper side surface of the paper side layer; (2) the second member of the pair floats over 1, 2 or 3 consecutive paper side layer weft yarns; and (3) the first member of the pair interlaces with one weft yarn in the machine side layer beside a machine side layer warp yarn that interlaces with the same machine side layer weft yarn; (c) in a third segment of the unbroken warp path: (1) the first member of the pair interweaves with a third group of paper side weft yarns; (2) the second member of the pair interweaves with the same third group of paper side weft yarns; (3) both the first member and the second member each independently float over 1, 2 or 3 consecutive paper side weft yarns; and (4) both the first member and the second member together occupy a third part of the unbroken warp path; (d) in the paper side layer the unbroken warp path includes at least one first segment, at least one second segment, and at least one third segment, and at least one first or second segment is located between each of the third segments; (e) the first, second and third segments are of equal or unequal length; (f) the unbroken warp path in the paper side surface of the paper side layer occupied in turn by the first and the second member of each pair of intrinsic warp binder yarns has a single repeat pattern; (g) in the unbroken warp path in the paper side surface of the paper side layer occupied in turn by the first and second members of each pair of intrinsic warp binder yarns, each succeeding segment is separated in the paper side surface of the paper side layer by at least one paper side layer weft yarn; and (h) in the composite fabric the weave pattern of the first member of a pair of intrinsic warp binder yarns is the same, or different, to the weave pattern of the second member of the pair.