Base fabric for papermaking felt, papermaking felt, and method for producing papermaking felt

Abstract

A base fabric forms a warp-weft double woven structure. In the base fabric, the base fabric is made of an MD yarn in a MD direction and a CD yarn in a CD direction, and the base fabric includes a weave repeat. In the weave repeat, the CD yarn includes an upper CD yarn and a lower CD yarn, the MD yarn is woven into both of the upper CD yarn and the lower CD yarn, the MD yarn includes at least one combination of a first MD yarn and a second MD yarn adjacent to the first MD yarn in the CD direction, the weave repeat includes first to fourth structural units, and the weave repeat includes a location at which the first and the second structural units are formed in pairs on both surfaces of the base fabric.

What is claimed is: 
     
         1 . A base fabric for a papermaking felt, forming a warp-weft double woven structure and having a wet paper side surface and a roll side surface, wherein
 the base fabric is made of an MD yarn in a felt running direction (MD direction) and a CD yarn in a felt cross direction (CD direction), and   the base fabric comprises a weave repeat, and   in the weave repeat,   the CD yarn includes an upper CD yarn located on the wet paper side surface and a lower CD yarn located on the roll side surface,   the MD yarn is woven into both of the upper CD yarn and the lower CD yarn,   the MD yarn includes at least one combination of a first MD yarn and a second MD yarn adjacent to the first MD yarn in the CD direction,   the weave repeat includes a first structural unit, a second structural unit, a third structural unit, and a fourth structural unit,   the first structural unit represents a 1/1 plain weave structure formed by the upper CD yarn and the first MD yarn,   the second structural unit represents a 1/1 plain weave structure formed by the lower CD yarn and the second MD yarn,   the third structural unit represents a structural unit in which the first MD yarn alternately comes into contact with a wet paper side surface of the upper CD yarn, a roll side surface of the lower CD yarn, and a wet paper side surface of the upper CD yarn,   the fourth structural unit represents a structural unit in which the second MD yarn alternately comes into contact with a roll side surface of the lower CD yarn, a wet paper side surface of the upper CD yarn, and a roll side surface of the lower CD yarn, and   the weave repeat includes a location at which the first structural unit and the second structural unit are formed in pairs on both surfaces of the base fabric.   
     
     
         2 . The base fabric for a papermaking felt according to  claim 1 , wherein the lower CD yarn included in the third structural unit and the upper CD yarn included in the fourth structural unit are not adjacent in the MD direction. 
     
     
         3 . The base fabric for a papermaking felt according to  claim 1 , wherein the third structural unit and the fourth structural unit are formed in pairs on both surfaces of the base fabric. 
     
     
         4 . The base fabric for a papermaking felt according to  claim 1 , wherein each of the third structural unit and the fourth structural unit is not a twill weaving pattern. 
     
     
         5 . The base fabric for a papermaking felt according to  claim 1 , which has a basis weight of 850 g/m 2  or less. 
     
     
         6 . The base fabric for a papermaking felt according to  claim 1 , wherein the number of the CD yarns is 140 Numbers/5 cm or less. 
     
     
         7 . The base fabric for a papermaking felt according to  claim 1 , wherein the CD yarn is a twisted yarn. 
     
     
         8 . The base fabric for a papermaking felt according to  claim 7 , wherein the CD yarn is a twisted yarn formed by twisting two or more yarns. 
     
     
         9 . A papermaking felt comprising: the base fabric for a papermaking felt according to  claim 1 . 
     
     
         10 . The papermaking felt according to  claim 9 , wherein a nonwoven fabric is entangled on both the wet paper side surface of the base fabric and the roll side surface of the base fabric. 
     
     
         11 . The papermaking felt according to  claim 9 , which has a basis weight of 1700 g/m 2  or less. 
     
     
         12 . The papermaking felt according to  claim 9 , wherein a weight of the base fabric with respect to a weight of the entire papermaking felt is 11/20 or less. 
     
     
         13 . The papermaking felt according to  claim 9 , comprising seam loop portions at both ends. 
     
     
         14 . A method for producing the papermaking felt according to  claim 9 , the method comprising: in any order,
 weaving the first MD yarn with the upper CD yarn in a 1/1 plain weave structure, and weaving the first MD yarn with one of the lower CD yarns and two of the upper CD yarns, the lower CD yarns having another two lower CD yarns each being adjacent to the one lower CD yarn, the another two lower CD yarns being adjacent to the two upper CD yarns on a wet paper side, respectively, such that the first MD yarn is alternately in contact with a wet paper side surface of one of the two upper CD yarns, a roll side surface of the one lower CD yarn, and a wet paper side surface of the other of the two upper CD yarns; and   weaving the second MD yarn with the lower CD yarn in a 1/1 plain weave structure, and weaving the second MD yarn with one of the upper CD yarns and two of the lower CD yarns, the upper CD yarns having another two upper CD yarns each being adjacent to the one upper CD yarns, the another two upper CD yarns being adjacent to the two lower CD yarns on a roll side, respectively, such that the second MD yarn is alternately in contact with a roll side surface of one of the two lower CD yarns, a wet paper side surface of the one upper CD yarn, and a roll side surface of the other of the two lower CD yarns.