Disposable wearing article

1. A disposable wearing article, comprising:

a front waist covering panel;

a rear waist covering panel;

a crotch covering panel;

a waist-hole;

a pair of leg-holes;

each of said front and rear waist covering panels at least partially comprising a body facing sheet and an undergarment facing sheet, each of said sheets being elastically stretchable in a waist-surrounding direction of said article;

said two sheets being respectively formed of nonwoven fabrics and have regions in which said two sheets are placed upon each other and spaced from each other by air gaps in a thickness direction of the respective waist covering panel; and

said undergarment facing sheet of said two sheets defining said regions repetitively undulating in said waist-surrounding direction to form a plurality of gathers in an intermediate zone defined between said waist-hole and said leg-holes,

wherein the waist covering panels are free of waist elastic members, and a peripheral edge of said waist hole is rendered elastically stretchable solely by the elasticity of said two sheets of each said front and rear waist covering panels.

2. The wearing article set forth by claim 1 , wherein the nonwoven fabrics forming said two sheets have a fineness in a range of 0.1 to 7 dtx and a basis weight in a range of 10 to 30 g/m 2 .

3. The wearing article set forth by claim 1 , wherein the body facing sheet is substantially free of gathers and smother than the associated undergarment facing sheet.

4. The wearing article set forth by claim 1 , wherein said gathers are formed and present throughout an entire area of the undergarment facing sheet.

5. The wearing article set forth by claim 1 , wherein the body facing sheet is substantially free of gathers.

6. The wearing article set forth by claim 1 , wherein

each of said front and rear waist covering panels is obtained by bonding said body and undergarment facing sheets while stretching said body facing sheet in said waist-surrounding direction without stretching said undergarment facing sheet in said waist-surrounding direction, so that the said body and undergarment facing sheets have the same size in the waist-surrounding direction.

7. The wearing article set forth by claim 1 , wherein

each of said front and rear waist covering panels is obtained by bonding said body and undergarment facing sheets while stretching said body facing sheet in said waist-surrounding direction at a first stretched percentage and stretching said undergarment facing sheet in said waist-surrounding direction at a second stretched percentage lower than the first stretched percentage, so that the said body and undergarment facing sheets have the same size in the waist-surrounding direction.

8. The wearing article set forth by claim 1 , wherein said body facing sheet and said undergarment facing sheet are elastically contractible, within at least 5 seconds, to 1.1 times of respective initial lengths thereof upon relaxation after said two sheets have been stretched in the waist-surrounding direction to 1.5 times of the respective initial lengths.

9. A disposable wearing article, comprising:

a front waist region, a rear waist region and a crotch region extending in a longitudinal direction of said article between said front and rear waist regions;

at least one of said front and rear waist regions comprising an elastically stretchable inner non-woven fabric adapted to face a wearer's body in use, and an elastically stretchable outer non-woven fabric adapted to face away from the wearer's body in use;

said inner and outer non-woven fabrics being elastically stretchable in a transverse direction perpendicular to the longitudinal direction of said article;

said inner and outer non-woven fabrics being placed upon each other and directly bonded to each other at a plurality of intermittently arranged bonding spots; and

a plurality of elastic spacers which are elastic bands extending in parallel one to another in said transverse direction and are interposed between said inner and outer non-woven fabrics,

wherein, when said article is in a relaxed state without being stretched by external forces, gathers are formed in the outer non-woven fabric between adjacent said bonding spots whereas the inner non-woven fabric is substantially free of gathers, said gathers defining air gaps between the outer and inner non-woven fabrics,

wherein an entirety of each of said inner and outer non-woven fabrics is elastically stretchable in the traverse direction.

10. The wearing article set forth by claim 9 , wherein said gathers are present throughout an entire area of the outer non-woven fabric.

11. The wearing article set forth by claim 9 , wherein said elastic spacers are intermittently bonded in a non-stretched state to said inner non-woven fabric.

12. The wearing article set forth by claim 9 , wherein

said elastic spacers are directly, intermittently bonded to said inner non-woven fabric, and

when said article is in the relaxed stated, the inner non-woven fabric remains substantially gather-free despite the direct bonding of said inner non-woven fabric to said elastic spacers.

13. The wearing article set forth by claim 9 , further comprising waist elastic members other than said elastic spacers and attached to end edges of said front and rear waist regions to define an elasticized peripheral edge of a waist hole of the article;

wherein said gathers are present throughout the entire area of the outer non-woven fabric, including regions that are not coexistent with the waist elastic members and the elastic spacers.

14. The wearing article set forth by claim 13 , wherein said waist elastic members are bonded in a non-stretched state to said inner non-woven fabric.

15. The wearing article set forth by claim 9 , wherein, when said article is in the relaxed state,

between each pair of the bonding spots that are adjacent in the transverse direction, the inner non-woven fabric is substantially flat, whereas the outer non-woven fabric describes a curve convex away from the inner non-woven fabric.

16. A disposable wearing article, comprising:

a front waist region, a rear waist region and a crotch region extending in a longitudinal direction of said article between said front and rear waist regions;

at least one of said front and rear waist regions comprising an elastically stretchable inner non-woven fabric adapted to face a wearer's body in use, and an elastically stretchable outer non-woven fabric adapted to face away from the wearer's body in use;

said inner and outer non-woven fabrics being elastically stretchable in a transverse direction perpendicular to the longitudinal direction of said article;

said inner and outer non-woven fabrics being placed upon each other and directly bonded to each other at a plurality of intermittently arranged bonding spots;

wherein, when said article is in a relaxed state without being stretched by external forces, gathers are formed in the outer non-woven fabric between adjacent said bonding spots whereas the inner non-woven fabric is substantially free of gathers, said gathers defining air gaps between the outer and inner non-woven fabrics,

wherein

end edges of said front and rear waist regions define a peripheral edge of a waist hole of the article; and

said peripheral edge of said waist hole is rendered elastically stretchable solely by the elasticity of said inner and outer non-woven fabrics.

17. The wearing article set forth by claim 16 , wherein said inner and outer non-woven fabrics are elastically contractible, within at least 5 seconds, to 1.1 times of respective initial lengths thereof upon relaxation after said two fabrics have been stretched to 1.5 times of the respective initial lengths.