Stretchable absorbent article having lateral and longitudinal stretch properties
View Patent ↗Absorbent articles with carefully controlled stretch properties are disclosed. In particular, the articles exhibit stretch not only in the lateral direction but also in the longitudinal direction. Specifically, the articles have a biaxial stretch ratio, which refers to a ratio of stretch along the hip circumference of the article to the amount of stretch in the longitudinal direction, that is from about 1.0 to about 2.5, and particularly from about 1.1 to about 1.5. Absorbent articles made in accordance with the present invention are capable of accommodating a relatively large size range of wearers. The articles also exhibit improved fit and prevent sagging or drooping of the crotch region, even after the crotch region has been wetted.
1. A biaxially stretchable absorbent article comprising:
an outer cover;
a bodyside liner joined to the outer cover in a superimposed relation;
an absorbent structure positioned in between the outer cover and the liner; and
wherein the absorbent article includes a front region, a back region and a crotch region, the front region and back region defining a waist opening when worn about a wearer, the crotch region being positioned in between two leg openings that are located opposite the waist opening, the absorbent article including a longitudinal direction extending from the front region, through the crotch region and to the back region, and a lateral direction generally parallel to the circumference of the waist opening and perpendicular to the longitudinal direction, the absorbent article including a hip circumference in the lateral direction that is located so as to circumscribe the hips of a wearer and wherein the absorbent article is stretchable so as to have a biaxial stretch ratio of from about 1.0 to about 2.5, the biaxial stretch ratio being defined by the formula:
Biaxial
Stretch
Ratio
=
%
Stretch
Along
the
Hip
Circumference
%
Stretch
in
the
Longitudinal
Direction
wherein:
%
Stretch
Along
the
Hip
Circumference
=
(
Hip
Circumference
at
2000
g
-
Hip
Circumference
at
70
g
)
Hip
Circumference
at
70
g
×
100
%
Stretch
in
the
Longitudinal
Direction
=
(
Length
of
Article
at
500
g
-
Length
of
Article
at
70
g
)
Length
of
Article
at
70
g
×
100.
2. A biaxially stretchable absorbent article as defined in claim 1 , wherein the article has a biaxial stretch ratio of from about 1.0 to about 1.3.
3. A biaxially stretchable absorbent article as defined in claim 1 , wherein the article has a biaxial stretch ratio of from about 1.3 to about 2.0.
4. A biaxially stretchable absorbent article as defined in claim 1 , wherein the article has a biaxial stretch ratio of from about 1.1 to about 1.5.
5. A biaxially stretchable absorbent article as defined in claim 1 , wherein the article has a biaxial stretch ratio of from about 1.1 to about 1.3.
6. A biaxially stretchable absorbent article as defined in claim 1 , wherein the article has a biaxial stretch ratio of from about 1.3 to about 1.4.
7. A biaxially stretchable absorbent article as defined in claim 1 , wherein the outer cover is biaxially stretchable.
8. A biaxially stretchable absorbent article as defined in claim 1 , wherein the outer cover is biaxially elastic.
9. A biaxially stretchable absorbent article as defined in claim 1 , wherein the outer cover, bodyside liner and absorbent structure form a chassis and wherein the absorbent article further comprises opposing pairs of front and back side panels attached to the chassis, the front and back side panels for attaching the chassis around the torso of a wearer.
10. A biaxially stretchable absorbent article as defined in claim 8 , wherein the liner is biaxially stretchable.
11. A biaxially stretchable absorbent article as defined in claim 1 , wherein the percent stretch in the longitudinal direction of the article is from about 5% to about 30%.
12. A biaxially stretchable absorbent article as defined in claim 1 , wherein the percent stretch in the longitudinal direction of the article is from about 10% to about 25%.
13. A biaxially stretchable absorbent article as defined in claim 11 , wherein the article includes a front waist zone and a back waist zone, each waist zone comprising from about 15% to about 20% of the total length of the absorbent article, and wherein at least 80% of the percent stretch in the longitudinal direction of the article resides in the waist zones.
14. A biaxially stretchable absorbent article as defined in claim 11 , wherein the article includes a front waist zone and a back waist zone, each waist zone comprising from about 15% to about 20% of the total length of the absorbent article, and wherein at least 90% of the percent stretch in the longitudinal direction of the article resides in the waist zones.
15. A biaxially stretchable absorbent article as defined in claim 9 , wherein each pair of side panels includes an attachment device for releasably attaching the corresponding side panels together.
16. An absorbent article comprising:
a biaxially stretchable outer cover, the outer cover comprising a film or a laminate containing a nonwoven material;
a biaxially stretchable bodyside liner joined to the outer cover in a superimposed relation;
an absorbent structure positioned in between the outer cover and the liner;
and wherein the absorbent article includes a front region, a back region and a crotch region, the front region and back region defining a waist opening when worn about a wearer, the crotch region being positioned in between two leg openings that are located opposite the waist opening, the absorbent article including a longitudinal direction extending from the front region, through the crotch region and to the back region, and a lateral direction generally parallel to the circumference of the waist opening and perpendicular to the longitudinal direction, the absorbent article including a hip circumference in the lateral direction that is located so as to circumscribe the hips of a wearer and wherein the absorbent article is stretchable so as to have a biaxial stretch ratio of from about 1.1 to about 1.5, the biaxial stretch ratio being defined by the formula:
Biaxial
Stretch
Ratio
=
%
Stretch
Along
the
Hip
Circumference
%
Stretch
in
the
Longitudinal
Direction
wherein:
%
Stretch
Along
the
Hip
Circumference
=
(
Hip
Circumference
at
2000
g
-
Hip
Circumference
at
70
g
)
Hip
Circumference
at
70
g
×
100
%
Stretch
in
the
Longitudinal
Direction
=
(
Length
of
Article
at
500
g
-
Length
of
Article
at
70
g
)
Length
of
Article
at
70
g
×
100.
17. An absorbent article as defined in claim 16 , wherein the outer cover is elastic.
18. An absorbent article as defined in claim 16 , wherein the liner is elastic.
19. An absorbent article as defined in claim 16 , wherein the article has a biaxial stretch ratio of from about 1.1 to about 1.3.
20. An absorbent article as defined in claim 16 , wherein the article has a biaxial stretch ratio of from about 1.3 to about 1.4.
21. An absorbent article as defined in claim 16 , wherein the outer cover, bodyside liner and absorbent structure form a chassis and wherein the chassis is responsible for all stretch in the longitudinal direction.
22. An absorbent article as defined in claim 16 , wherein the percent stretch in the longitudinal direction of the article is from about 5% to about 30%.
23. An absorbent article as defined in claim 16 , wherein the percent stretch in the longitudinal direction of the article is from about 10% to about 25%.
24. An absorbent article as defined in claim 22 , wherein the article includes a front waist zone and a back waist zone, each waist zone comprising from about 15% to about 20% of the total length of the absorbent article, and wherein at least 80% of the percent stretch in the longitudinal direction of the article resides in the waist zones.
25. An absorbent article as defined in claim 22 , wherein the article includes a front waist zone and a back waist zone, each waist zone comprising from about 15% to about 20% of the total length of the absorbent article, and wherein at least 90% of the percent stretch in the longitudinal direction of the article resides in the waist zones.
26. A biaxially stretchable absorbent article comprising:
a chassis comprising a biaxially elastic outer cover, a biaxially stretchable bodyside liner and an absorbent structure positioned in between the outer cover and the liner, the outer cover comprising a film or a laminate containing a nonwoven material, the absorbent structure containing superabsorbent particles;
opposing pairs of front and back side panels attached to the chassis, the side panels for securing the article around the torso of a wearer;
the absorbent article including a front region, a back region, and a crotch region, the front region and the back region defining a waist opening when worn about a wearer, the crotch region being positioned between two leg openings that are located opposite the waist opening, the absorbent article including a longitudinal direction extending from the front region through the crotch region to the back region and a lateral direction generally parallel to the circumference of the waist opening and perpendicular to the longitudinal direction, the absorbent article including a hip circumference in the lateral direction that is located so as to circumscribe the hips of a wearer;
a pair of elastic containment flaps connected to the chassis that extend generally in the longitudinal direction in at least the crotch region;
a pair of leg elastic members that at least partially surround each of the leg openings;
and wherein the absorbent article is stretchable so as to have a biaxial stretch ratio of from about 1.0 to about 2.5, the biaxial stretch ratio being defined by the formula:
Biaxial
Stretch
Ratio
=
%
Stretch
Along
the
Hip
Circumference
%
Stretch
in
the
Longitudinal
Direction
wherein:
%
Stretch
Along
the
Hip
Circumference
=
(
Hip
Circumference
at
2000
g
-
Hip
Circumference
at
70
g
)
Hip
Circumference
at
70
g
×
100
%
Stretch
in
the
Longitudinal
Direction
=
(
Length
of
Article
at
500
g
-
Length
of
Article
at
70
g
)
Length
of
Article
at
70
g
×
100.
27. A biaxially stretchable absorbent article as defined in claim 26 , wherein the article has a biaxial stretch ratio of from about 1.1 to about 1.5.
28. A biaxially stretchable absorbent article as defined in claim 26 , wherein the percent stretch in the longitudinal direction of the article is from about 5% to about 30%.
29. A biaxially stretchable absorbent article as defined in claim 28 , wherein the article includes a front waist zone and a back waist zone, each waist zone comprising from about 15% to about 20% of the total length of the absorbent article, and wherein at least 80% of the percent stretch in the longitudinal direction of the article resides in the waist zones.
30. A biaxially stretchable absorbent article as defined in claim 28 , wherein the article includes a front waist zone and a back waist zone, each waist zone comprising from about 15% to about 20% of the total length of the absorbent article, and wherein at least 90% of the percent stretch in the longitudinal direction of the article resides in the waist zones.