WARPED STITCHED PAPERMAKER'S FORMING FABRIC WITH FEWER EFFECTIVE TOP MD YARNS THAN BOTTOM MD YARNS

摘要

A warped stitched fabric is provided to widen the upper surface opening area, enhance the performance for supporting upper CMD(Cross Machine Direction) yarns, improve the drainage capacity, and stabilize the surface topography. A fabric(10) for papermaking comprises a series of repeat patterns. Each of the repeat patterns includes a set of upper MD(Machine Direction) yarns(11-14), a set of upper CMD yarns(31-46) interwoven with the upper MD yarns, a set of lower MD yarns, a set of lower CMD yarns interwoven with the lower MD yarns, and a set of stitching yarns(21-28). The stitching yarns are disposed in pairs. At least one of the yarns of each of the stitching yarn pairs is interwoven with the upper CMD yarns and the lower CMD yarns. When a first stitching yarn of a stitching yarn pair is interwoven with the upper CMD yarns, a second stitching yarn of the stitching yarn pair passes below the upper CMD yarns. When the second stitching yarn of the stitching yarn pair is interwoven with the upper CMD yarns, the first stitching yarn of the stitching yarn pair passes below the upper CMD yarns. As a result, each of the stitching yarn pairs forms a composite upper MD yarn. The set of upper MD yarns includes a first number of upper MD yarns, the set of stitching yarns includes a second number of composite upper MD yarns, and the set of lower MD yarns includes a third number of lower MD yarns. The ratio of the sum of the first number and the second number to the third number is 2:3.