Connectable disposable wear article and method of detecting sticking defect of target sheet in manufacture thereof

A method of detecting a sticking defect of a target sheet in a manufacture of a connectable disposable wear article, the connectable disposable wear article comprising:

• a crotch portion including a center in a front-back direction, a ventral side part extending forward from the center in the front-back direction, and a dorsal side part extending backward from the center in the front-back direction;
• connecting portions to be detachably connected to an outer surface of the ventral side part and that are provided on both side portions of the dorsal side part, each of the connecting portions being a hook material of a mechanical fastener, and
• a target sheet to which the connecting portions are to be connected and which is provided on the outer surface of the ventral side part,
• wherein the target sheet is a nonwoven fabric of which constituent fibers have a fineness of 5 to 10 dtex, and
• wherein the target sheet further has a basis weight of 20 to 40 g/m2, a thickness of 0.3 to 0.8 mm, contains a white pigment, and wherein a whiteness of all corner portions on at least one of an inner surface and an outer surface of the target sheet is 80% or more,
• the method comprising:
• sticking the target sheet to an outer surface constituent member of the ventral side part, irradiating the target sheet from its side having a surface whose whiteness of all corner portions is 80% or more with white light and detecting transmitted light transmitted to an opposite surface;
• detecting at least all corners of the target sheet based on a difference in light transmittance between a part having the target sheet and a part not having the target sheet;
• and
• detecting a sticking defect of the target sheet depending on whether or not the target sheet recognized based on a detection result is normal.