Grooved-shape monofilaments and the fabrics made thereof

Abstract

A monofilament with longitudinally oriented grooves and fabrics made thereof having reduced air permeability, wherein the reduced permeability is achieved without using additional coatings or stuffer yarns. Bicomponent monofilaments made from these grooved monofilaments using solution or wire coating have improved coating adhesion and may also include a conductive coating.

We claim:  
     
         1 . A fabric comprising a plurality of uncoated functional monofilaments having a grooved-shaped cross-section and having reduced air permeability compared with a fabric not having said monofilaments.  
     
     
         2 . The fabric of  claim 1  wherein a surface of each respective monofilament has a plurality of grooves formed thereon.  
     
     
         3 . The fabric of  claim 2  wherein each groove is C-shaped.  
     
     
         4 . The fabric of  claim 2  wherein each groove has an open angle less than 180 degrees.  
     
     
         5 . The fabric of  claim 1  wherein the fabric is a forming, press, dryer, TAD, pulp forming, sludge filter, chemiwasher, or engineered fabric.  
     
     
         6 . A monofilament having a plurality of longitudinal grooves formed in its surface.  
     
     
         7 . The monofilament of  claim 6  wherein each groove is C-shaped.  
     
     
         8 . The monofilament of  claim 6  wherein each groove has an open angle less than 180 degrees.  
     
     
         9 . The monofilament of  claim 6  wherein coating adhesion is improved.  
     
     
         10 . The monofilament of  claim 6  wherein the grooved monofilament is made of a material selected from the group consisting essentially of polyester, polyamide, poly(phenylene sulfide), polyetheretherketone, poly(aryl ether ketone), polyethylene, and polypropylene.  
     
     
         11 . A fabric comprising a plurality of grooved-shaped functional monofilaments and having improved adhesion to coatings compared with a fabric not having said grooved-shaped monofilaments.  
     
     
         12 . The fabric of  claim 11  wherein said fabric has improved adhesion to lamination substrates mechanically interlocked by way of a flow of thermoplastic material.  
     
     
         13 . The fabric of  claim 11  wherein the improved adhesion is achieved due to mechanical interlock regardless of the coating chemistry.  
     
     
         14 . The fabric of  claim 11  wherein the improved adhesion is achieved by an interlocking mechanism between the coating and the yarns in the fabric.  
     
     
         15 . The fabric of  claim 11  wherein the fabric is a forming, press, dryer, TAD, or engineered fabric.  
     
     
         16 . A bicomponent monofilament made from a coated grooved-shaped monofilament.  
     
     
         17 . The bicomponent monofilament of  claim 16  having improved delamination resistance compared with a bicomponent monofilament not made from a coated grooved-shaped monofilament.  
     
     
         18 . The bicomponent monofilament of  claim 16  wherein the bicomponent monofilament is made using solution coating.  
     
     
         19 . The bicomponent monofilament of  claim 16  wherein the bicomponent monofilament is made using wire coating.  
     
     
         20 . The bicomponent monofilament of  claim 16  wherein said bicomponent monofilament has a conductive coating.  
     
     
         21 . A die used for extruding groove-shaped monofilaments and having a capillary cross section with a plurality of projections oriented towards an interior of the capillary, wherein an angle centering at the origin of a respective projection and facing into said interior is over 250 degrees, and the open angle defined as the angle centering at the origin of a C and facing its outlet is much less than 180 degrees.  
     
     
         22 . The die of  claim 21  wherein a diameter of the capillary is approximately three times the size of the monofilaments to be produced.  
     
     
         23 . The die of  claim 21  wherein the ratio of length to diameter of the capillary is approximately 3:1.  
     
     
         24 . The die of  claim 21  wherein the monofilaments to be produced are made of PET.  
     
     
         25 . The die of  claim 21  wherein the monofilaments are extruded according to a melt spinning process.