Wearable article production method, wearable article, and wearable article production device

A production method of a wearable article including a stretchable sheet having stretchability, an absorbent main body that is attached to a predetermined attachment location in the stretchable sheet and is configured to absorb water, a front part, and a back part, the production method comprising:

• ultrasonically welding a pair of sheet bodies and an elastic film to each other at a plurality of joints separated from each other in a predetermined transport direction in a region of a front abdomen constituting the front part and a back abdomen constituting the back part including the attachment location by transporting a sheet laminate formed by sandwiching the elastic film in an elongated state between the pair of sheet bodies in the transport direction so that the sheet laminate passes between an anvil roll and an ultrasonic horn to form the stretchable sheet, the plurality of joints being uniformly formed throughout an entirety of the region of the front abdomen and the back abdomen of the stretchable sheet;
• applying a weakening treatment to a specified portion of the stretchable sheet to form a weakened region in the attachment location after the ultrasonic welding, the weakened region having a smaller stretchability than another portion of the stretchable sheet to which no weakening treatment has been applied;
• and
• attaching the absorbent main body to the attachment location so that the absorbent main body overlaps the weakened region,
• wherein the applying of the weakening treatment includes forming the weakened region at least at a part of the attachment location by forming a plurality of notches so as to be separated from each other in the transport direction and an orthogonal direction that is orthogonal to the transport direction in the stretchable sheet, a length of each notch in the orthogonal direction being larger than a diameter of each joint in the orthogonal direction.