Dryer fabric seam
View Patent ↗An industrial fabric is described which comprises a woven fabric body having opposing ends. The fabric repeating weave pattern includes at least two systems of vertically stacked machine direction warp yarns interwoven with at least one system of cross machine direction weft yarns. On each end of the fabric at least some of the warp yarns form a first set of loops each of which is at a first angle to the machine direction, at least some of the warp yarns form a second set of loops each of which is at a second angle to the machine direction and each of the second set of loops is substantially concentric with the first set of angled loops to provide double end loops which can be seamed by using a coil seam or a pin seam. This fabric structure has the advantage that it is possible to use all of the fabric warp yarns in the loops, thus significantly increasing the tensile strength of the seam. It also permits the fabrication of a flatter seam. This seam design is of particular use in dryer fabrics for a paper making machine.
1. A woven industrial fabric, having a machine direction (MD) and a cross-machine direction (CD) and comprising a fabric body with opposing first and second fabric ends each oriented in the CD and each comprising a seaming area, the fabric further having opposing first and second lateral edges each oriented in the MD, an upper surface and a lower surface which together form the fabric body and comprising CD oriented weft yarns and MD oriented warp yarns interwoven with the weft yarns in a weave pattern in which:
(a) in the fabric body, all of the warp yarns comprise vertically stacked pairs of upper and lower warp yarns, the upper warp yarns each following an upper body path, and the lower warp yarns each following a lower body path; and
(b) in each of the seaming areas, each of the upper warp yarns follows an upper seaming path in the upper surface which passes from the upper surface to the lower surface to form a yarn loop, passes under at least one weft yarn and thereafter follows a lower seaming path in the lower surface, wherein
(i) the lower seaming path is vertically stacked below the upper seaming path of an adjacent warp yarn towards a selected one of the first and second lateral edges; and
(ii) in the seaming area, the yarn loops form concentric pairs, each pair comprising
(A) an outer loop canted at a first angle to the MD; and
(B) an inner loop canted at a second angle to the MD.
2. A fabric according to claim 1 , wherein the first angle and the second angle are oriented towards each other in the MD.
3. A fabric according to claim 1 , wherein the first angle and the second angle are substantially similar.
4. A fabric according to claim 1 , wherein the fabric ends are closed by a coil having a spiral angle to form a coil seam, and the first angle and the second angle are each selected to correspond to the direction of the spiral angle.
5. A fabric according to claim 1 , wherein the fabric ends are prepared for closing by a pintle to form a pin seam, and the first angle and the second angle are each selected to provide for the loops on the first fabric end to be located opposite to spaces between the loops on the second fabric end, to facilitate interdigitation of the loops on the first and second fabric ends.
6. A fabric according to claim 1 , wherein the warp yarns are monofilaments.
7. A fabric according to claim 1 , wherein the fabric is a papermaking fabric.
8. A fabric according to claim 7 , wherein the fabric is a dryer fabric for a papermaking machine.