Compound forming fabric with additional bottom yarns

Abstract

A compound forming fabric having a top weave and a bottom weave. The fabric includes binder warp / weft yarns, where the binder yarns are arranged in groups of at least two interchanging binder yarns. Each group of the binder yarns forms an integral part at least of the top weave. Per group of binder yarns the number of bottom warp / weft yarns only weaving the bottom weave is higher than the number of top warp / weft yarns only weaving the top weave.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to compound forming fabrics, and, more particularly to a section of a papermachine to manufacture graphical paper, board and packaging paper, or tissue paper. [0003] 2. Description of the Related Art [0004] Compound forming fabrics are known in the art. Compound forming fabrics include a top or paper side weave and a bottom or machine side weave. The top and the bottom weave are bound together by binder yarns which alone or in combination can be binder warp or binder weft yarns and therefore weave with the top and bottom weft yarns of the top and bottom weave or with the top and the bottom warp yarns of the top and the bottom weave. [0005] The binder yarns further can be integral or so called fabric born binder yarns thereby forming at least an integral part of the top weave. U.S. Pat. No. 5,152,326 describes a compound forming fabric having integral binder yarns arranged in pairs. Alte...

AI Technical Summary

Benefits of technology

[0009] The present invention provides a compound forming fabric with good water drainage performance combined with sufficient stability.

[0012] By providing a compound forming fabric which has per group of binder yams a higher number of bottom warp yarns only weaving the bottom weave than the number of top warp yams only weaving the top weave a sufficient stability in general, especially a good dimensional stability and a good wear resistance is achieved and at the same time an open structure is maintained.

[0013] According to a preferred embodiment of the present invention, the number of bottom warp yams only weaving the bottom weave is one more than the number of top warp yarns only weaving the top weave. It was found by the Applicant that by providing one more bottom warp yam in the bottom weave than top warp yarn in the top weave per group of binder warp yarns for many applications sufficient stability can by achieved by maintaining a fabric having a good open structure.

[0014] According to a further preferred embodiment of the present invention there is foreseen that per group of binder yarns at least one of said bottom warp yams only weaving the bottom weave weaves over and under the same bottom weft yarns like said group of interchanging binder yarns. Therefore at least one of said bottom yarns forms the same knuckles and floats with the bottom weft yarns like the group of binder warp yarns, thereby creating pairs of knuckles and floats allowing to use larger diameter bottom weft yarns and thereby increasing the wear resistance of the compound fabric.

[0021] To increase the wear resistance of the compound forming fabric on the one hand and to provide an open top weave structure on the other hand it is desirable, if the diameter of the binder yams is less than the diameter of the bottom yarns extending in the direction of the binder yarns.

Problems solved by technology

On the other hand, if the paper side surface is made less dense to provide sufficient drainage the fabric stability is not sufficient.

On the other hand if the paper side surface is made less dense to provide sufficient drainage the fabric stability is not sufficient.

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