PROBLEM TO BE SOLVED: To obtain an underpants type disposable diaper having an elongation/contraction structure.SOLUTION: There is provided a manufacturing method of an underpants type disposable diaper which has a front body part and a rear body part, and is folded in a front/rear direction center of a product, both side parts of which are joined to each other, and on which a waist opening and a right/left pair of leg openings are formed. The diaper is formed by combining an interior body with an exterior body. The manufacturing method of an underpants type disposable diaper includes: a step of supplying a first sheet layer 20A formed of a nonwoven fabric, a second sheet layer 20B formed of a nonwoven fabric, and an elastic film layer 30 in a state of being elongated between the sheet layers to joining seal means by material welding continuously, respectively a step of performing joining at a large number of joining parts by the joining seal means in a state in which the elastic film layer 30 is elongated in an elongation direction with respect to the first sheet layer 20A and the second sheet layer 20B and a step performing folding in the front/rear direction center of the diaper orthogonal to the elongation direction and joining both the side parts of the diaper to each other in a state of including the first sheet layer 20A, the second sheet layer 20B, and the elastic film 30.SELECTED DRAWING: Figure 18COPYRIGHT: (C)2017,JPO&INPIT【課題】伸縮構造を有するパンツタイプ使い捨ておむつを得る。【解決手段】前身頃及び後身頃を有し、製品の前後方向中央で折り畳まれ、その両側部が相互に接合され、ウエスト開口及び左右一対のレッグ開口が形成されたパンツタイプ使い捨ておむつの製造方法において、内装体と外装体とが組み合わされたものであり、 不織布からなる第1シート層20Aと、不織布からなる第2シート層20Bと、それらの間に伸長された状態の弾性フィルム層30とを、それぞれ連続的に素材溶着による接合シール手段に供給するステップ、前記弾性フィルム層30が、前記第1シート層20A及び第2シート層20Bに対して前記伸長方向に伸長された状態で、前記接合シール手段により多数の接合部で接合するステップ、前記第1シート層20A、前記第2シート層20B及び前記弾性フィルム30を有する状態で、前記伸長方向と直交するおむつの前後方向中央で折り畳み、おむつの両側部を相互に接合するステップ、を有する。【選択図】図18
