Method of manufacturing sheet, method of manufacturing material of absorbent article, and apparatus to manufacture sheet

A method of manufacturing a sheet formed, in a predetermined portion of the sheet, with a region having a different flexibility property, the sheet configuring an absorbent article, the method comprising:

• rotating in a circumferential direction both a first roll formed with a protruding portion group in a predetermined area of an outer circumferential face and the second roll arranged with an outer circumferential face opposing the first roll,
• forming, in the sheet, a region with the different flexibility property by passing the sheet in between the first roll and the second roll, and sandwiching the sheet with the protruding portion group and the outer circumferential face of the second roll,
• wherein the protruding portion group has a plurality of rows of protruding portion rows with intervals therebetween in the circumferential direction, each of the protruding portion rows including a plurality of protruding portions inclined relative to a rotational axis of the first roll,
• wherein a position of a downstream end in the circumferential direction of at least one protruding portion of the protruding portions configuring the protruding portion row positioned most downstream of the protruding portion group in the circumferential direction is shifted from a position of a downstream end of another protruding portion configuring the protruding portion row,
• wherein the protruding portions in each of the protruding portion rows do not overlap each other in the circumferential direction,
• wherein each of the protruding portions is a blade having a substantially triangular cross-section shape and an edge of the blade at a top of the substantially triangular cross-section shape is linear, and
• wherein the protruding portions in the protruding portion rows adjacent to each other in the circumferential direction are not overlapped with each other in respect to the circumferential direction.