Absorbent articles providing improved fit when wet

Details Absorbent articles providing improved fit when wet Absorbent articles providing improved fit when wet

2000-10-25

2004-03-30

Lo, Weilun (Department: 3765)

Surgery

Means and methods for collecting body fluids or waste material

Absorbent pad for external or internal application and...

C604S385101, C604S367000, C604S366000

Reexamination Certificate

active

06713661

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to absorbent structures useful in absorbent articles such as diapers, incontinent briefs, training pants, diaper holders and liners, sanitary hygiene garments, and the like. More particularly, the invention relates to absorbent structures that provide articles having improved fit and comfort when dry and particularly when wetted with bodily fluids.
BACKGROUND OF THE INVENTION
Infants and other incontinent individuals wear absorbent articles such as diapers to absorb and retain urine and other body exudates. Absorbent articles function both to contain the discharged materials and to isolate these materials from the body of the wearer and from the wearer's garments and bed clothing. Disposable absorbent articles having many different basic designs are known in the art. For example, U.S. Pat. No. Re. 26,152, entitled “Disposable Diaper” issued to Duncan and Baker on Jan. 31, 1967, describes a disposable diaper which has achieved wide acceptance and commercial success. U.S. Pat. No. 3,860,003, entitled “Contractable Side Portions For Disposable Diaper”, issued to Buell on Jan. 14, 1975, describes an elastic leg cuff disposable diaper which has achieved wide acceptance and commercial success.
Many diaper designs are relatively wide and bulky, when dry and particularly when wet, in the region of the article that fits between the legs of the wearer. This results in a certain level of discomfort to the wearer, as these diapers tend to bunch when worn. In an effort to address wearer discomfort, U.S. Pat. No. 4,610,678 (Weisman et al.) describes diapers comprising densified cores that are thinner in this region than were prior designs. Nonetheless, even these articles store significant levels of absorbed fluids in the discharge region of the article. This discharge region is positioned within the portion of the article that fits in the wearer's crotch region when worn.
Since prior absorbent articles do not effectively distribute fluid, these articles are typically designed to store significant quantities of fluid in the crotch region of the diaper. Thus, upon each loading, this region of the article becomes increasingly bulky and therefore tends to be more uncomfortable for the wearer. See, for example, U.S. Pat. No. 5,098,423 to Pieniak et al., which builds on the disclosure of the Weisman patent, and describes a low dry bulk disposable diaper. The focus of the '423 patent is an article having a relatively low cross sectional area, when dry, particularly in the “impact zone” (defined in the patent as the second and third fifths of the article's length). Indeed, an important aspect of the described articles is the ability of the absorbent material in the impact zone to absorb fluid. The patent specifically indicates that at least 60% of the total absorbed fluid is retained in the diaper's impact zone. Thus, while the patent discusses the desire for improved fit when dry, it fails to address the issue of providing improved fit and comfort throughout the entire wearing period. Moreover, the primary consideration for improving fit is on thin and wide structures which fold and bunch during use, without optimizing narrowness and bulk, dry and wet, of the absorbent material in the crotch region. Accordingly, the articles described in the '423 patent have in the crotch region an overall low cross sectional area when dry, accomplished by providing a relatively thin (i.e., in the article's the z-dimension), relatively wide (i.e., in the article's x-dimension) core. However, the core retains 60% of its absorbent capacity in the crotch region. This results in excess bulk, thickness, thereby reducing the comfort and fit when the article is wetted with body fluid.
Several attempts have been made to provide articles, such as diapers, with increased storage capacity outside of the crotch region. U.S. Pat. No. 4,994,037 (Bernardin, et al.) discloses diapers with absorbent core designs comprising superabsorbent material located in either one or both waist regions of the absorbent core. The structures described therein show low efficiencies of the material usage in the waist regions of the article, because of substantially higher capacity in the crotch region than in either of the waist regions. Although it is pointed out in U.S. Pat. No. 4,994,037, that the superabsorbent material does absorb some liquid, it is not recognized therein that the liquid pick up further away form of the loading area is still significantly reduced. In addition, the reference describes the use of fluff components, especially around the loading region, which thus inevitably will result in a high rewetting tendency of the article.
It therefore would be advantageous to provide an absorbent structure that provides better fit and wearer comfort, even after the structure is wetted with body fluids. It would be further advantageous to provide an absorbent structure which has reduced bulk in the crotch region in both the dry and wet states. Such structures would provide absorbent articles having improved fit and comfort, even when wetted with body fluids.
Therefore, it is an object of the present invention to provide an absorbent structure having improved fit on the wearer during use by reducing the structure's crotch width dry as well as when the structure is wetted with fluid.
It is a further object of the present invention to provide an absorbent structure that provides reduced caliper in the crotch region of the product when dry as well as when wet which in turn positively impacts comfort and fit.
It is a further object of the present invention to provide an absorbent structure that provides improved comfort for the wearer resulting from the structure's ability to readily acquire, distribute and store a significant amount of fluid remote from the crotch region of the structure.
It is a further object of the present invention to provide absorbent articles which have low rewet values, thereby providing improved skin dryness.
It is a further object of the present invention to provide articles that more effectively distribute body exudates such that higher absorbent capacities can be achieved even against gravitational forces.
It is a further object of the invention to provide absorbent articles comprising these absorbent structures.
These and other objects of the present invention will be more readily apparent when considered in reference to the following description and when taken in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
The present invention provides absorbent structures for inclusion in absorbent articles such as diapers, incontinent briefs, training pants, diaper holders and liners, feminine hygiene garments, and the like, designed to provide improved fit and comfort for the wearer while adequately containing body exudates. Such an absorbent article has a containment assembly (chassis) typically comprising a liquid pervious topsheet and a substantially liquid impervious backsheet, and an absorbent core associated with the outer covering layer. The absorbent core is designed so as to be relatively narrow and thin in the crotch region of the diaper, even when the core absorbs significant amounts of fluid during use. To achieve this, the absorbent core is designed such that fluid is moved substantially from the crotch region to the front and/or rear waist regions of the article.
Thus, the absorbent article has an absorbent capacity as determined by the Whole Article Vertical Wicking test, wherein capacities are determined for segments of the article positioned in vertical distance away from the folding line of the article, and wherein the absorbent capacity for a segment at 13.5 cm is at least 0.5 times the capacity for the segment at 0 cm, preferably at least 0.75 times, more preferably 1.25, and most preferably at least two times.
Suitable absorbent articles can also be described by respective calipers at the crotch, namely by the Saturated Crotch Caliper (SCC), and the Actual Wet Crotch Caliper (A

Affiliated with

Also associated with

Rating

Absorbent articles providing improved fit when wet does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Absorbent articles providing improved fit when wet, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Absorbent articles providing improved fit when wet will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3251949