Patent ID: 9296151
Filing Date: 2016-03-29
CPC Classification: A61F,B29C,B29L,D04H,D06C

Claim Text:
1. A method of producing a stretchable sheet, the method comprising: forming a plurality of recessed sections on a raw sheet by pressing the raw sheet, the plurality of recessed sections being formed collinearly at least along a drawing direction before drawing the raw sheet at a pair of gear rolls; preparing the pair of gear rolls each having a plurality of teeth arranged on a circumference thereof, the pair of gear rolls being rotatable about respective axes of rotation with the plurality of teeth meshing with each other; and drawing the raw sheet, on which the plurality of recessed sections has been formed, in the drawing direction using the plurality of teeth, by passing the raw sheet through a gap between the pair of gear rolls, the raw sheet containing a plurality of types of fibers, the drawing direction being either a direction of rotation of the pair of gear rolls or a direction parallel to the axes of rotation, wherein each gear roll of the pair of gear rolls has the plurality of teeth arranged at an arrangement pitch in the drawing direction, the plurality of recessed sections in the raw sheet includes a plurality of rows of recessed sections, each row among the plurality of rows including a number of the recessed sections arranged collinearly along the drawing direction, the plurality of rows being arranged side-by-side in a direction orthogonal to the drawing direction, in the respective plurality of rows of recessed sections, the plurality of recessed sections is formed at respective predetermined formation pitches along the drawing direction, with respect to each row among the plurality of rows of the plurality of recessed sections in the raw sheet, the arrangement pitch of the teeth in the drawing direction is greater than the respective formation pitch in said each row of the plurality of rows and smaller than twice the respective formation pitch in said each row, the plurality of rows of recessed sections includes the first predetermined value and the second predetermined value are different from each other, the arrangement pitch of the plurality of teeth in the drawing direction is greater than the first predetermined value and smaller than twice the first predetermined value, and the arrangement pitch of the plurality of teeth in the drawing direction is greater than the second predetermined value and smaller than twice the second predetermined value.