Strip Means and an Improved Suction Roll for a Material Web Machine and an Arrangement and a Method for Improving the Duration of the Suction Roll

Abstract

A sealing strip of a suction roll ( 4 ) for a material web machine includes a longitudinal strip element ( 3 ) and a longitudinal holder ( 2 ) shaped as a U profile open in the direction of a facing surface ( 41 ). An element first layer ( 31 ) is an easily adjusting material and a second layer ( 34 ) is a stiffer material in the loading direction than the first layer. The strip element may be loaded so it or its edge does not substantially bend in the direction of movement of the facing surface. To optionally reduce the effect of abrasion: an inner mantel surface is treated by grain blasting, thermal injection coating, chemical or electro-chemical precipitation coating and/or polymer-based coating; and/or a lubricant or additive is fed between surfaces abrading against each other; and/or at least part of suction holes in a wall of the mantel are broached ( 71 ).

1 - 38 . (canceled) 
   
   
       39 . A seal comprising:
 a U-shaped suction sealing strip holder extending in an axial direction, the U-shaped holder opening in a second direction;   a suction roll strip having a first part made of a first material, and a second part made of a second material, the first part mounted for motion in the second direction within the U-shaped holder, the second part of the suction roll strip joined to the first part, the second part for abutting a cylindrical surface opposite the second part;   a biasing element contained within the U-shaped holder between the first part and the U-shaped holder, the biasing element arranged to move the suction roll strip in the second direction;   wherein the material of the first part is less stiff in the second direction than the material of the second part, and wherein the second part is selected such that the second part can not be substantially bent in a direction transverse to the second direction; and   wherein the first part has portions which abut the biasing element defining a plurality of notches which extend substantially in the transverse direction with respect to the strip element and which notches are separated from each other by unnotched projections.   
   
   
       40 . The seal of  claim 39 , wherein the notches are filled with a filler material which is less stiff than the first material. 
   
   
       41 . The seal of  claim 40 , wherein the notches are filled with foam plastic. 
   
   
       42 . The seal of  claim 39 , wherein portions of the suction roll strip form feeding channels extending from the notches to the portions of the second part abutting the inside cylindrical surface. 
   
   
       43 . The seal of  claim 39 , wherein the second part of the suction roll strip is joined to the first part by glue. 
   
   
       44 . The seal of  claim 39 , wherein the second part of the suction roll strip is joined to the first part by a dovetail joint. 
   
   
       45 . The seal of  claim 39  further comprising a teflonpolytetrafluoroethylene layer on inside edges of the U-shaped suction sealing strip holder. 
   
   
       46 . A vacuum roll comprising:
 a suction roll mantel, having an inside cylindrical surface defining an axis, the suction roll mantel mounted to rotate about the axis in a first substantially transverse direction with respect to the axis, and portions of the roll forming a plurality of holes extending through the roll mantel and portions forming chamfers around each hole adjoining the cylindrical inside surface, the inside cylindrical surface formed of a grain blasted layer overlaid by a coating;   a U-shaped suction sealing strip holder mounted within the suction roll mantle, and extending in a direction defined by the axis;   a suction roll strip having a first part made of a first material, and a second part made of a second material, the first part mounted in the U-shaped holder, the second part of the suction roll strip joined to the first part and having portions abutting the inside cylindrical surface opposite the second part;   a biasing element contained within the U-shaped holder between the first part and the U-shaped holder, the biasing element defining a loading direction extending from the biasing element to the inside cylindrical surface opposite the second part;   wherein the first material of the first part is less stiff in the loading direction than the material of the second part, and wherein the second part is selected such that the second part cannot be substantially bent in the first substantially transverse direction.   
   
   
       47 . The vacuum roll of  claim 46  wherein the first part has portions which abut the biasing element defining a plurality of notches which extend substantially in the first substantially transverse direction with respect to the strip element and which notches are separated from each other by unnotched projections. 
   
   
       48 . The vacuum roll of  claim 47  wherein the notches are filled with a filler material which is less stiff than the first material. 
   
   
       49 . The vacuum roll of  claim 48  wherein the notches are filled with foam plastic. 
   
   
       50 . The seal of  claim 47 , wherein portions of the suction roll strip form feeding channels extending from the notches to the portions of the second part abutting the inside cylindrical surface. 
   
   
       51 . The seal of  claim 46 , wherein the second part of the suction roll strip is joined to the first part by glue. 
   
   
       52 . The seal of  claim 46 , wherein the second part of the suction roll strip is joined to the first part by a dovetail joint. 
   
   
       53 . The seal of  claim 46 , wherein the coating overlaying the grain blasted layer is a thermal injection coating. 
   
   
       54 . The seal of  claim 46  further comprising a teflonpolytetrafluoroethylene layer on inside edges of the U-shaped suction sealing strip holder. 
   
   
       55 . A vacuum roll comprising:
 a suction roll mantel, having an inner cylindrical surface, defining an axis, the suction roll mantel mounted to rotate about the axis in a first substantially transverse direction with respect to the axis and portions of the roll forming a plurality of holes extending through the roll mantel, and the inner surface having compression stresses of the type generated by means of grain blasting;   a U-shaped suction sealing strip holder mounted within the suction roll mantle, and extending in a direction defined by the axis;   a suction roll strip having a first part made of a first material, and a second part made of a second material, the first part mounted in the U-shaped holder, the second part of the suction roll strip joined to the first part and having portions abutting the inner surface of the roll mantel;   a biasing element contained within the U-shaped holder between the first part and the U-shaped holder, the biasing element defining a loading direction extending from the biasing element to the inner surface of the roll mantel;   wherein the first material of the first part is less stiff in the loading direction than the material of the second part, and wherein the second part is selected such that the second part cannot be substantially bent in the first substantially transverse direction.   
   
   
       56 . The vacuum roll of  claim 55  further comprising portions forming chamfers around each of the plurality of holes, said chamfers adjoining the inner cylindrical surface. 
   
   
       57 . The vacuum roll of  claim 55  wherein the second material is a composite carbon fiber material. 
   
   
       58 . The vacuum roll of  claim 55  wherein the inner surface of the roll mantel has a lightly ground finish. 
   
   
       59 . The vacuum roll of  claim 55  wherein the first part has portions which abut the biasing element defining a plurality of notches which extend substantially in the first substantially transverse direction with respect to the suction roll strip and which notches are separated from each other by unnotched projections.