Dryer fabric for papermaking machine and method

A method of drying a web of paper material which includes passing the web through a dryer having a plurality of heated cylinders, holding said web in contact against said heated cylinders by contacting said web with an endless travelling dryer fabric, said dryer fabric having controlled air passage which permits passage of air therethrough and through said web of paper without excessive sheet flutter due to air pumping through said fabric, said method including providing an endless travelling dryer fabric which comprises:

• a plurality of elongated helix means extending in a cross-wise direction constructed from a polymeric material characterized by stress and heat resistance to which said fabric is subjected during endless travel about rollers at elevated drying temperatures;
• joint means joining adjacent ones of said helix means successively together in a machine direction to form an endless belt of desired dimension;
• spaced upper and lower generally parallel loop runs included in said helix means defining a smooth generally flat contacting surface;
• an open mesh defined in said fabric between adjacent joint means and runs of said loops along the cross-wise and machine dimensions of said fabric through which heated vapor and the like flow and are transferred outwardly from said paper web;
• polymeric filler means inserted across said helix means closing said mesh to reduce said flow and control air pumping through said fabric and reduce fluttering of said web of paper thereagainst;
• means sealing edges of said fabric retaining said filler means and helix means as integral fabric structure.

A method of constructing a dryer fabric for a dryer section of a papermaking machine so as to have a desired permeability and control of air flow therethrough comprising:

• providing a series of elongated helix means oriented in a cross-wise direction in said fabric constructed from a polymeric material having open helix loops defined by upper and lower generally parallel loop runs of said material;
• joining said helix means successively to one another to form a basic endless dryer fabric of desired dimension in a machine direction having a paper contacting surface which includes an open mesh permeable to fluids;
• closing said mesh of said basic dryer fabric by inserting polymeric filler means inside said helix loops across the entire width of said fabric in said cross-wise direction to reduce the permeability of said fabric and control the flow of air through said fabric and reduce paper flutter during drying;
• and
• sealing lateral edges of said polymeric fabric to retain said fabric and filler means as integral fabric structure.

A dryer belt fabric for use with apparatus for drying a web of paper material in a dryer section of a papermaking machine which includes a plurality of heated cylinders over which the web travels for drying and said fabric is arranged as an endless traveling dryer belt carried about rollers and adjacent said cylinders contacting said web to hold said web against said heated cylinders forcing out air in an area between said web and cylinder for drying, wherein said dryer belt fabric comprises:

• a non-woven heat set fabric which includes a plurality of elongated helix means extending in a cross-wise direction constructed from a polymeric material having a degree of plasticity of accommodating stress during repeated travel over said rollers at elevated drying temperatures;
• said helix means including flattened loops having generally parallel upper and lower runs of said material presenting asmooth generally flat web contacting surface;
• joint means joining adjacent ones of said helix means successively together in a machine direction to provide an endless dryer belt of desired dimension;
• an open fabric mesh defined between said joint means and runs of said loops through which air flows;
• polymeric filler means capable of withstanding said drying temperatures inserted between said runs in each said helix loop across the entire width of said fabric in said cross-wise direction to close said fabric mesh and control the flow of air through said dryer belt and reduce fluttering of said web of paper against said fabric during drying;
• and
• a heat sealed seam along edges of said fabric sealing said filler means and fabric providing integral fabric structure.