Woven multilayer papermaking fabric having increased stability and permeability and method

In a fluid permeable woven multilayer papermaking fabric having a paper support side and a roller contact side of the type which includes a single layer yarn system with yarns extending in a first direction of said fabric and a multiple layer yarn system with yarns extending in a second direction normal to said first direction, wherein said multiple layer yarn system includes a first warp layer consisting of a number of first load bearing warp yarns extending in said second direction which is in a machine direction in which said fabric travels on a papermaking machine;

• and a second warp layer consisting of a number of second load bearing warp yarns extending in said machine direction on said roller contact side of said fabric;
• said warp yarns of said first and second warp layers being arranged one on top of the other in a superposed configuration to define pairs of stacked load bearing warp yarns extending in said machine direction along the entire fabric length facilitating increased fabric stability in said machine direction;
• said single layer yarn system consisting of a warp balancing weft yarn woven in a cross-machine direction in a balancing weave pattern which balances said stacked pairs to maintain said warp yarns one on top of the other generally without relative lateral shifting;
• and adjacent ones of said stacked pairs of warp yarns being relatively positioned in a cross-machine direction to provide a desired degree of fabric permeability.

A method of weaving a multilayered papermaking fabric having a weave pattern which provides increased fabric stability in a machine direction and fluid permeability comprising:

• weaving a first warp layer having first load bearing warp yarns extending in said machine direction;
• weaving a second warp layer having second load bearing warp yarns extending in said machine direction;
• weaving a weft yarn in the cross-machine direction with said warp yarns in said first and second layers;
• weaving respective ones of said first and second warp yarns of said first and second warp layers on top of each other to define stacked pairs of warp yarns in said weave pattern along the entire fabric length;
• weaving said weft yarn in a cross-machine direction with said first and second load bearing warp yarns in said first and second layers in a pattern to balance and maintain said warp yarns in said stacked pairs;
• and
• arranging said stacked pairs of warp yarns relative to each other in said cross-machine direction to provide a desired fabric permeability while providing said increased fabric stability in said machine direction.

A highly permeable woven multilayer papermaking machine fabric having increased fabric stability in the machine direction of a papermaking machine comprising:

• a first upper warp layer of load bearing warp yarns extending in said machine direction;
• a second lower warp layer of load bearing warp yarns extending in said machine direction;
• stacked warp yarn pairs defined by respective ones of said upper and lower warp yarns of said first and second warp layers arranged in a generally vertically stacked position one over the other along the entire fabric length;
• said stacked warp yarn pairs being spaced apart next adjacent one another in a cross-machine direction in said fabric to provide a desired fabric open area;
• and
• a warp balancing weft yarn interwoven with said first and second warp layers to bind said respective ones of upper and lower warp yarns in said stacked pairs in generally vertical arrangement.