Koichi Morimoto, Beijing, China; Takashi Umeo, Nishinomiya, Japan; Hiroyuki Ueno, Kobe, Japan; and Katsuhiro Yonemura, Kobe, Japan. Assigned to The Procter & Gamble Company, Cincinnati, OH.

Filed: 6/12/12
Issued: 3/8/16

A disposable pull-on diaper comprising: a longitudinal axis and a lateral axis; an absorbent main body comprising a liquid pervious topsheet, a liquid impervious backsheet, and an absorbent core disposed therebetween; wherein the absorbent main body has left and right longitudinally extending side edges, and front and back transversely extending end edges that intersect with the longitudinally extending side edges at substantially a right angle, longitudinally opposing front and back waist panels, and a crotch panel between the waist panels, at least one leg elastic material disposed in proximity to each of said side edges and extending generally linearly and longitudinally, parallel with the longitudinal axis, along said side edges; a ring-like elastic belt comprising a front belt portion and a back belt portion joined to each other at side seams such that the back belt extends beyond the front belt at two leg openings, each of said front belt portion and back belt portion has transversely extending proximal and distal edges, the distal edge of the ring-like elastic belt defines a waist opening, the proximal edge being located closer than the distal edge relative to the crotch panel of the absorbent main body, each of said front belt portion and back belt portion has a central panel, and left and right side panels contiguous with its central panel; wherein the transversely extending proximal edges of the front and back belt portions are longitudinally offset from each other, but are parallel with each other and with the transverse axis; wherein the ring-like elastic belt comprises a belt substrate layer and a plurality of waist elastic strands and a plurality of side panel elastic strands each extending in the transverse direction, parallel with the lateral axis, and attached to the belt substrate layer; wherein said waist elastic strands are disposed in proximity to the distal edge and said side panel elastic strands are disposed at least in the left and right side panels, and wherein the ring-like elastic belt has a stretched waist circumferential length and a free-state waist circumferential length; wherein, the central panel of the front belt portion is joined to the front waist panel of the absorbent main body, the central panel of the back belt portion is joined to the back waist panel of the absorbent main body, and the proximal edge of the respective left and right side panels of the front belt portion and the back belt portion together with the left and right side edges of the crotch panel of the absorbent main body defines the two leg openings, each of the leg opening has a leg opening length which can be calculated according to the following formula: leg opening length=Le+Sf+√Sb²+La² wherein Le indicates leg elastic length, Sf indicates front side panel elastic length, Sb indicates back side panel elastic length and La indicates the difference in a longitudinal length of the front belt portion and back belt portion; and wherein said stretched waist circumferential length is no greater than about 700 mm, and the ratio of the stretched waist circumferential length to the free-state waist circumferential length is from about 2.5 to about 2.8; and wherein said leg opening length is from about 250 mm to about 300 mm; wherein a longitudinal length of the front belt (LF) is less than a longitudinal length of the back belt (LB).