Method and apparatus for manufacturing absorbent article

A method of manufacturing an absorbent article including a front waistline portion to be fitted to a waistline of a wearer and a back waistline portion to be fitted to a back waistline of the wearer, the method comprising:

• a front-and-back waistline division step of dividing a strip-shaped web into (i) a front waistline web including the front waistline portion and (ii) a back waistline web including the back waistline portion;
• a web reversing step of reversing the front waistline web and the back waistline web, and concurrently setting a gap between the front waistline web and the back waistline web in a width direction of the front and back waistline webs by a web reversing mechanism,
• a web conveying step of conveying the front waistline web and the back waistline web, with the front and back waistline webs being arranged side by side in the width direction of the front and back waistline webs;
• a flap attaching step of attaching a flap portion onto one of the front waistline portion of the front waistline web and the back waistline portion of the back waistline web by a flap transferring mechanism, the flap portion fixed to said one of the front waistline portion and the back waistline portion to be temporarily attached to the other waistline portion when being worn;
• and
• a web gap changing step of changing the gap between the front waistline web and the back waistline web,
• wherein
• the front-and-back waistline division step is performed before the web conveying step,
• the web reversing step is performed after the front-and-back waistline division step and before the web conveying step,
• the web reversing mechanism includes:
• a first bar-shaped portion having a first contact portion coming into contact with the front waistline web;
• and
• a second bar-shaped portion having a second contact portion coming into contact with the back waistline web,
• in a plan view of the front and back waistline webs, positions of the first bar-shaped portion and the second bar-shaped portion are shifted from each other in a web conveyance direction in which the front and back waistline webs are conveyed before coming into contact with the first bar-shaped portion,
• in the plan view of the front and back waistline webs, the first bar-shaped portion and the second bar-shaped portion are inclined with respect to the web conveyance direction by approximately same angles,
• the web reversing mechanism conveys the front waistline web while reversing front and back surfaces of the front waistline web along the first contact portion, and conveys the back waistline web while reversing front and back surfaces of the back waistline web along the second contact portion,
• the web gap changing step is performed after the flap attaching step, and
• in the flap attaching step, when the size of the absorbent article is changed, the flap transferring mechanism attaches the flap portion to the one of the front and back waistline webs without a change of the gap between the front waistline web and the back waistline web, so that the position of the flap portion is kept constant.

An apparatus for manufacturing an absorbent article including a front waistline portion to be fitted to a front waistline of a wearer, a back waistline portion to be fitted to a back waistline of the wearer, and a crotch portion to be fitted to a crotch of the wearer, the crotch portion arranged between the front waistline portion and the back waistline portion, the apparatus comprising:

• a web conveying mechanism configured to convey a strip-shaped front waistline web including the front waistline portion and a strip-shaped back waistline web including the back waistline portion, with the front and back waistline webs being arranged side by side in a width direction of the front and back waistline webs;
• and
• a web gap changing mechanism configured to change a gap between the front waistline web and the back waistline web which are being conveyed by the web conveying mechanism, wherein
• the web gap changing mechanism is configured to convey at least one of the front waistline web and the back waistline web, and includes:
• a pair of first web guiding portions arranged in a web conveyance direction;
• and
• at least one second web guiding portion arranged between the pair of first web guiding portions on a conveyance path of said at least one of the front and back waistline webs,
• in a view in the width direction, which is perpendicular to the web conveyance direction, and along the surface of the web, the second web guiding portion is arranged at a position where a step is formed in the conveyance path of the web being conveyed between the pair of first web guiding portions,
• in the plan view of the web, a first contact line and a second contact line run in the width direction, the first contact line running along a first contact surface on which one of the first web guiding portions and the web come into contact with each other, the second contact line running along a second contact surface on which the other of the first web guiding portions and the web come into contact with each other, and
• in the plan view of the web, a third contact line is inclined with respect to the first contact line and the second contact line, the third contact line running along a third contact surface on which the second web guiding portion and the web come into contact with each other.