JPH0451181B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to disposable absorbent articles. A variety of disposable absorbent components have been proposed for use in capturing and retaining human body spills. These absorbent articles include, for example, disposable diapers, sanitary napkins, etc., and they consist of a back sheet that does not allow liquids to pass through, a cover or top sheet that allows liquid to pass through, and a crushed wood material called fluff that is interposed between the back sheet and cover sheet. Usually composed of absorbent pads such as pulp. Although their popularity has increased due to their reusability, several problems remain with absorbent pads that prevent them from being completely satisfactory. First of all, it is necessary for the pad to quickly spread from the point where the outflow from the body exits to the farthest part of the pad, to minimize local penetration of the pad and maximize the capacity of the entire pad. The pad then retains body spills away from the cover sheet and
It is desirable to reduce the discomfort caused to the wearer due to the back side turning up through the back sheet.
Furthermore, the padding must be soft and easily conform to the wearer's body shape, allowing the article to properly fit and provide maximum comfort. Finally, padding is a simple manufacturing technique, which should reduce the cost of disposable items to consumers. U.S. Pat. It consists of a first butt and a second butt or pad located between the first butt and the back seat, and has a compressed portion extending over a substantial portion of the second pad and an uncompressed portion adjacent to the compressed portion. Such pads are functionally superior to conventional single pad disposable articles. U.S. Pat. No. 3,612,055 describes a single pad diaper that is treated to form a paper-like skin on one side not in contact with the cover sheet to allow liquid to be transferred to the back side of the diaper. ing. The main object of the present invention is to provide an absorbent article of simple construction with improved liquid transmission and retention capabilities. The disposable absorbent article of the present invention comprises a backsheet of fluid-impermeable material, a fluid-permeable coversheet, and a first absorbent article adjacent to the coversheet comprising a loosely formed mass of fibers. A disposable absorbent article comprising: a pad; and a second absorbent pad disposed between the first absorbent pad and the backsheet and made of a mass of fibers,
The second absorbent pad includes the second absorbent pad in at least a portion of the second absorbent pad such that the average fiber spacing of the second absorbent pad is substantially smaller than the average fiber spacing of the first absorbent pad. the second absorbent pad has a higher density than the first absorbent pad, the ratio of the density of the second absorbent pad to the density of the first absorbent pad is in the range of about 1.5:1 to about 7:1;
The absorbent pad has a density of about 0.03 to about 0.07 g/cm ³ , and the second absorbent pad has a density of about 0.14 to about 0.22 g/cm ^{3 .}
It is characterized by having a density of . A feature of the invention is that the compressed area of the second pad absorbs bodily exudate from the first pad and quickly directs the exudate away from the second pad. Another feature of the invention is that dissipated effluent is retained in a compressed region of the second pad remote from the cover sheet. Therefore, the feature of the present invention is that the pad reduces the spillage of body fluids through the cover sheet,
The goal is to maintain the cover sheet in a relatively dry condition during use of the article. A further feature of the invention is that the pad can be made in a simple manner, reducing costs. Embodiments of the present invention will be described in detail below with reference to the drawings. Referring to Figures 1 and 2, there is shown at 20 a disposable absorbent article, illustrated as a disposable diaper. Although for convenience the article of the invention will be described as a disposable diaper, it will be appreciated that the principles of the invention are equally applicable to other single-use absorbent articles such as sanitary napkins and underpads. As shown, the article or diaper 20 includes a liquid impermeable pad assembly 21, such as polyethylene, forming a back surface 23 of the pad assembly over a back surface 28 of a pad structure 26;
A liquid permeable top or cover sheet 24, such as a non-woven material, forms the majority of the front surface 25 of the pad assembly.
and an absorbent pad structure, generally designated 26, interposed between the backsheet and coversheet. Referring to FIG. 1, the diaper 20 has fasteners 38 for securing the diaper to the infant during installation, the backsheet 22 has an edge 32 that is folded over and secured to the cover sheet 24, and the edge 32 has an edge 32 that secures the diaper to the infant during installation. The sides of the structure 26 can be covered. As shown in FIGS. 1 and 2, the absorbent pad 26
includes a first pad or absorbent layer 40 located adjacent to the cover sheet 24, the first pad and the back sheet 2;
A second pad or absorbent layer 42 is interposed between the two. The pad structure 26 has a top quad seat 34 that covers the front surface 30 of the upper first pad 40 and a back quad seat 36 that covers the rear surface 28 of the lower second pad 42. In one type, as shown in the figure, the rear surface 41 of the first pad 40 is connected to the front surface 43 of the second pad 42.
However, in other types, a liquid permeable sheet such as a wad sheet may be interposed between the first and second pads, respectively. The first pad 40 is made from a loosely formed fibrous body, such as ground wood pulp, known in the art as fluff. If desired, the first absorbent layer may be dense, but the first pad may provide minimal compressibility in order to obtain a soft fluff front absorbent layer 40 with relatively large fiber spacing. The density of the first absorption layer 40 is approximately 0.03 g/cm ³ and approximately 0.07
g/ ^cm3 , preferably about 0.04
g/cm ³ and about 0.07 g/cm ³ , more preferably about
It is between 0.06 g/cm ³ and about 0.07 g/cm ³ . The second pad 42, like the first pad 40, is made from a fibrous material such as ground wood pulp, but the pad is compressed or otherwise suitably known in the art.
Between 0.14 g/cm ³ and about 0.22 g/cm ³ , preferably about
between 0.16g/ ^cm3 and 0.20g/ ^cm3 , more preferably
Densities between 0.18 g/cm ³ and 0.20 g/cm ³ are provided. Within the above density variables, the ratio of the density of the second pad 42 to the density of the first pad 40 is approximately 1.5:
1 to about 7:1, preferably 2:1 to about 5:1
1, more preferably about 2:1 to 4:1.
Of course, the density is simply determined from the given weight of the measured volume (length x width, thickness of the layer measured as described below). The thickness of the padded layer can vary widely, but generally the ratio of the thickness of the first layer to the second layer is about 50:1 to 1:1.
1, preferably 20:1 to 2:1, more preferably
10:1 to 4:1, about 40 mil overall
Combined to give a thickness of 1500 mils (about 1 mil to about 40 mils). All thicknesses are padded
Measurement is based on a load of 4.1g/cm ³ .
This is because, without such a load, the value would change due to the rising ability and elasticity of the fluff pad. The density variable is therefore dependent on such thickness determination. In infant diapers, the overall pad thickness is clearly generally smaller than in adult incontinence pads and diapers and feminine hygiene napkins. A typical newborn diaper has an overall pad thickness of about 1 mm to about 6 mm or about 2 mm to 10 mm depending on the style. For larger babies, the overall pad thickness is about 2 mm to about 8 mm or about 3 mm to about 12 mm.
Sanitary napkin pads typically range from about 3mm to about 3mm, depending on the particular style of sanitary napkin.
10 mm or about 4 mm to about 20 mm or more, such as about 6 mm to about 40 mm. Additionally, it is desirable to ensure that the overall pad fluff weight varies commensurately with changes in pad thickness and size. As an indicator, such weight varies from about 10 grams to 20 grams and even up to about 100 grams. Additionally, generally, the weight ratio of the upper pad to the lower pad can vary from about 2:1 to about 1:2, but is preferably about the same. This is especially true since it is the simplest to manufacture. Therefore,
For example, a single web of fluff can be formed in any conventional manner and then split into a lower layer compressed as desired in accordance with the present invention. In use, diaper 20 is secured to the infant by tape fasteners 38. During excretion, urine reaches the local area of the first pad 40 through the cover sheet 24;
Because the distance between the fibers of the compressed second pad is relatively small, fluid flows from the first absorbent layer 40 to the second pad 42.
is rapidly absorbed by the body. Additionally, the compressed pad 42 quickly directs fluid to portions of the pad away from the point where urine spilled into the diaper. A relatively large portion of the fluff material has been compressed during the manufacture of pad 42, so that the relative size of the fiber spacing allows fluid to spread quickly into pad 42, although the fluid holding capacity is less than that of pad 40. , the overall pad structure 26 can hold approximately the same weight of fluid as a non-compressible pad, such as a tank that holds body effluent locally, but allows urine to be removed more quickly and more effectively. Because of the diffusion, there is little leakage after each urine release, significantly reducing backside wetting, thereby keeping the cover sheet 24 relatively dry. In this manner, the first and second pads 40 and 42 each cooperate to maximize the use of pad material and
The cover sheet 24 is kept relatively dry. As previously mentioned, the first pad 40 is substantially uncompressed and therefore soft and conformable. Therefore, the first
and second pads 40 and 42 each increase comfort;
To provide a pad structure for a diaper that is soft and conforms to the wearer's body for convenient attachment of the diaper. Furthermore, the pad structure 26 of the present invention
It is simply made by compressing the pads and then placing the first pad 40 facing the second pad 42 during manufacture of the diaper. Diapers are thus made without the need for wetting and drying the compressed areas, which heretofore added complexity and construction costs. Referring to FIG. 3, the pad assembly 21 of FIG.
is folded along a number of longitudinally extending fold lines to form the box-split configuration of the diaper. Thus, the diaper has a central panel 5 that is folded along a pair of first fold lines 50 and extends in the longitudinal direction.
2 and are bent along a pair of second fold lines 54 to form a pair of longitudinally extending first panels 56 interposed between fold lines 50 and 54 and extending from second fold lines 54. A pair of outer panels 58 are formed. Referring to FIG. 4, diaper 60 also includes area 62.
and an hourglass shape with four wider sections forming ears 64, 66, 68, and 70. The diaper includes a polyethylene or similar backsheet 72 and a cover sheet 74 similar to a box pleated diaper. An absorbent pad assembly 75 similar to the pads 26, 40, 42 of a box-sleet diaper is provided between the cover sheet and the back sheet. Box pleat diapers 34 and 3
6. A similar wand sheet 77 is provided as in the box pleated diaper. The pad assembly including the wand sheet is smaller in size than the cover sheet and back sheet of similar size as described above. The first diaper with standard pad (36 g wood fluff pad with uniform density of 0.1 g/cc - pad size is 300 mm x 409 mm) and the same size and weight as the first diaper, but above it. The density of the pads is
A second diaper with a two-layer pad of the present invention having a density of 0.06 g/cc and a lower pad density of 0.2 g/cc was subjected to a product blind test with 106 users and the following results were obtained.

[Table] Dry condition

[Table] The overall preference percentage of +1.49 corresponds well to a +2 sigma preference for two-layer padded diapers, with a 95% confidence level that the majority prefers two-layer padded diapers over traditional single-padded diapers. Shows that she likes diapers.

[Brief explanation of the drawing]

FIG. 1 is a front cutaway view of the absorbent article of the present invention shown as a disposable diaper, FIG. 2 is a cutaway cross-sectional view taken along line 2-2 in FIG. 1, and FIG. 3 is a box FIG. 4 is a perspective view of the article of FIG. 1 folded into a pleat shape, and FIG. 4 is a top view, partially broken away for clarity, of another type of disposable diaper. 20: Disposable diaper, 21: Padded assembly,
22: Liquid-impermeable back sheet, 24: Liquid-permeable cover sheet, 34: Upper Wad sheet,
36: Back quad seat, 40: First pad,
42: Second pad, 60: Diaper, 77: Wound sheet.

Claims (1)

[Claims] 1. A back sheet made of a fluid-impermeable material;
a fluid-permeable cover sheet, a first absorbent pad adjacent to the cover sheet and comprising a loosely formed mass of fibers, disposed between the first absorbent pad and the backsheet; and a second absorbent pad made of a mass of fibers, the second absorbent pad has an average inter-fiber spacing of the second absorbent pad that is greater than an average inter-fiber spacing of the first absorbent pad. at least a portion of the second absorbent pad has a higher density than the first absorbent pad, such that the density of the second absorbent pad is substantially smaller than that of the first absorbent pad. the ratio is in the range of about 1.5:1 to about 7:1, and the first absorbent pad is about 0.03 to about 0.07.
g/cm ³ and said second absorbent pad has a density of about
A disposable absorbent article characterized in that it has a density of 0.14 to about 0.22 g/cm ³ . 2. The disposable absorbent article of claim 1, wherein the thickness ratio of the first absorbent pad to the second absorbent pad ranges from about 20:1 to about 2:1. 3. The disposable absorbent article of claim 2, wherein the disposable absorbent article has a longitudinally oriented box pleat configuration. 4. A disposable absorbent article according to claim 2, which has an overall hourglass shape and has an elastic member in the central region of the sides to better fit around the wearer's legs.