Method for manufacturing stretchable sheet

A method for manufacturing a stretchable sheet, comprising:

• a supplying step in which a stretchable elastic film is interposed in a stretched state between a first sheet layer having no elasticity and a second sheet layer having no elasticity;
• and
• a bonding step in which, in a state where the elastic film is interposed in a stretched state between the first sheet layer and the second sheet layer in the supplying step, the first sheet layer and the second sheet layer are bonded directly or via an elastic film at a plurality of bonded portions by applying heat melt energy to a region of the plurality of bonded portions spaced apart from each other by a heat melting apparatus from the outside of the first sheet layer and the second sheet layer to melt the elastic film;
• wherein the heat melting apparatus has an anvil roll and an ultrasonic horn, the anvil roll has a plurality of protrusions spaced apart from each other in a roll length direction and an outer circumference direction on an outer surface of the anvil roll such that bonding is performed by the ultrasonic horn and a group of the protrusions of the anvil roll at a bonding position;
• wherein a counter roll is disposed apart from the anvil roll, and the elastic film is not nipped between the anvil roll and the counter roll;
• wherein a nip roll that nips the elastic film is disposed corresponding to the counter roll, and
• the elastic film passes through a nip position between the counter roll and the nip roll, along the counter roll, and then along the anvil roll,
• wherein a circumferential speed of the anvil roll is faster than a circumferential speed of the counter roll and the nip roll to stretch the elastic film;
• wherein a holding angle α from the nip position to a position where the elastic film is separated from the counter roll is 300° to 30°, and a holding angle β from a position where the elastic film starts to be held by the anvil roll to the bonding position is 270° to 30°,
• wherein a distance between the nip position and the bonding position is less than 250 mm;
• and
• wherein a distance from a position where the elastic film is separated from the counter roll to the position where the elastic film starts to be held by the anvil roll is 50 mm or less.