DK154045B - Disposable diaper - Google Patents

Description

in

DK 154045 B

The present invention relates to a disposable diaper of the kind set forth in claim 1.

A rich variety of disposable items have been proposed for use in receiving and retaining body fluids. Such objects, e.g. Disposable diapers, sanitary napkins and the like have usually been constructed with a fluid-impermeable backing, a fluid-impervious cover, an absorbent pad between the back and cover layers, e.g. finely divided wood pulp, which in the art is referred to as lint. Although they are still gaining in popularity because they can be disposed of after single use, certain problems remain with the absorbent pads which prevent the items from being completely satisfactory.

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First, it is necessary that the pads quickly disperse the body fluids from the receiving point to distant places in the cushion to minimize cushion saturation in local areas and maximize the cushion capacity. Secondly, it is desirable that the pads preferably retain the body fluid at locations spaced from the cover layer to reduce backflow through the cover layer with associated discomfort to the wearer to a minimum. Third, the pillows should be soft and able to assume the shape of the wearer to provide proper fit of the items and maximum comfort.

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Finally, the cushions should be manufactured in accordance with simplified manufacturing methods to reduce the cost of disposable items to the user.

From DK Patent Application No. 3251/77, a disposable diaper having a fluid impervious backing layer and a fluid impervious cover layer is known, a cushion unit having a first absorbent pad comprising a loosely shaped fibrous mass adjacent to the cover layer, and between the first pad and the backing layer a second fibrous mass or cushion with compressed areas over a portion of the second cushion 35 and also with non-compressed areas adjacent to the compressed areas. Such a cushion is functionally superior to a known disposable diaper of the type having a single cushion, yet it has been found that its flux 2

DK 154045 B

idiomatic and restraining ability is not fully sufficient, and it is relatively complicated to manufacture.

U.S. Pat. No. 3,612,055 discloses a diaper construction having a single pad in which one surface is not in contact with the cover layer formed to form a paper-like web to effect fluid spread to the back of the diaper.

It is an object of the present invention to provide a disposable diaper which, in comparison to the known diapers, has a simpler construction and is thus cheaper to manufacture while having a better fluid spreading and retaining ability.

This object is met by the fact that the first-mentioned 15 disposable diapers are peculiar to that of the characterizing part of claim 1. The loose fibers in the first pad can receive and absorb sudden streams of body fluid, and the second pad is obtained by its denser fiber mass rapidly transmitting body fluid to distant locations in the second pad for storage in this remote from the cover layer, the first cushion, the front padding layer and the center of the cushion, thereby reducing the possibility of back wetting.

Practical embodiments are set forth in the characterizing part 25 of claim 2.

In the drawing, FIG. 1 is a top view of a disposable diaper according to it

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FIG. 2 is a sectional view taken substantially as indicated along line 2-2 of FIG. 1, 35 FIG. 3 is a perspective view of the disposable diaper shown in FIG. 1, as folded into a pastry shape, and 3

DK 154045B

FIG. Fig. 4 shows a top view of a disposable diaper according to the invention with individual parts removed for the sake of clarity.

Although, for convenience, the article of the present invention will be described as a disposable diaper, it is to be understood that the principles of the invention are equally applicable to other disposable absorbent articles such as sanitary napkins and wound compress, etc. As shown, the diaper 20 has an absorbent pad unit 21 having a fluid-impervious backing layer 22, such as polyethylene, defining a backing surface 23 of the cushion unit and covering a backing surface 28 of the pad 26, a fluid-permeable covering layer 24 such as nonwoven material defining a substantial portion of the fronting surface 25 of the cushion unit, and an absorbent cushion, which is designated in its entirety by reference numeral 26 between the backing layer 22 and the cover layer 24. Referring to FIG. 1, the diaper 20 may have a pair of adhesive tape fasteners 38 for attaching the diaper to a child during laying, and the backing layer 22 may have transverse lateral edges 32 folded over and attached to the cover layer 24 such that the edges 32 cover side portions of the pad. 26th

As shown in FIG. 1 and 2, the absorbent pad 26 has a first absorbent pad or first absorbent layer 40 disposed adjacent to the cover layer 24 and a second absorbent pad or a second absorbent layer 42 disposed between the first pad 40 and the backing layer 22. The pad 26 may have a top padding layer 34 covering a front surface 30 of the upper first pad 40 and a rear padding layer 36 covering a back surface 28 of the lower second pad 42. In one embodiment, as shown, a 30 rear surface 41 of the first cushion 40 is placed against a front surface 43 of second cushion 42, or, in an alternative embodiment, a fluid-permeable layer, such as a padding layer, can be inserted between the first and second cushions 40 and 42, respectively.

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DK 154045B

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The first pad 40 is made of a loosely shaped mass of fibers, such as finely divided wood pulp, which in this technique is referred to as lint. Although the first cushion may be compressed, if desired, the first cushion 40 may have a minimal compression to achieve a soft, fluffy front cushion 40 with a relatively large gap between the fibers.

3 The density of the top pad 40 should be between approx. 0.03 g / cm and 3 3 15 approx. 0.07 g / cm, preferably between ca. 0.04 g / cm and approx.

3 3 0.07 g / cm and most preferably between ca. 0.06 g / cm and approx. 0.07 3 g / cm. The second lower cushion 42 is also made from a pulp such as finely divided wood pulp, similar to the cushion 40, but this cushion is pre-treated, such as by compression 20 or any other suitable known means, to a density of between 0.14 g / cm and approx. 0.22 g / cm, preferably from ca.

3 3 3 0.16 g / cm and 0.20 g / cm, with a density of between 0.18 g / cm 3 and 0.20 g / cm being the most preferred. Within the above-described density parameters, it is desirable that the ratio 25 for the density of the lower pad 42 to that of the top pad 40 be from approx. 1.5: 1 to approx. 7: 1, preferably approx. 2: 1 to approx. 5: 1, with the ratio of the particularly preferred embodiment being from approx. 2: 1 to 4: 1. The densities are, of course, simply determined from a given weight of a measured volume (length 30 x width x thickness, the last being measured as described below).

The thickness of the cushions may vary within a wide range, but they are generally combined to give a total thickness of approx. 1 to approx. 40 mm with the ratio of the thicknesses of the top cushion to the bottom cushion lying in the range of about 50: 1 to 1: 1, preferably 20: 1 to 2: 1, with the most preferred range being between 10: 1 and 4: 1. All thicknesses are based on

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5 2 measurements with a load of 4.1 g / cm on the cushion, since the curvature and elasticity of the cushion without such a load will give varying values. The density parameters are then based on such thickness determinations.

5 For child diapers, the overall cushion thickness for obvious reasons will generally be less than for pillows and diapers for adults with involuntary urination and for sanitary napkins for women. Typically, diapers for newborn babies can have a total cushion thickness of approx. 1 mm to approx. 6 mm or approx. 2 mm to approx. 10 10 mm depending on the type of diaper. For larger toddlers, the cushion thickness seat totals can range from approx. 2 mm to approx. 8 mm or approx. 3 mm to approx. 12 mm. The total thickness of sanitary napkins is typically in the range of approx. 3 mm to approx. 10 mm, or approx.

4 mm to approx. 20 mm or more, e.g. ca. 6 mm to approx. 40 mm 15 which in turn depends on the special design of the sanitary napkin.

Furthermore, it may be desirable to emphasize that the total weight of the pillowcases will of course vary considerably, as will the thickness and size of the pillows. As a guide, it can be said that such weights can range from approx. 10 to 20 g and up to approx. In general, it can again be said that the ratio of the weights of the top pads to the bottom pads can vary from approx. 2: 1 to 1: 2, but preferably be about the same, especially if this allows for the greatest possible simplification in manufacture. Thus, e.g. a single web of lint is formed in any of the known ways and then split and compressed for use on the bottom layer as desired.

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In use, the diaper 24 is fastened to a child by adhesive fastener 38. During urination, urine passes through the cover layer 24 into a local area of the first pad 40, and thanks to the relatively small spaces between the fibers 35 in the compressed second pad 42, the fluid pads are rapidly absorbed from the first pad 40 by the second pad 42. The compressed pad 42 also rapidly transmits the fluid pads to pad areas distant from the point.

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where the urine is applied to the diaper. Although a relatively large amount of fluff material has been compressed during the manufacture of the pad 42 and thus has a smaller fluid retention capacity, the pad 40 due to the relative size 5 of their spacing between the fibers allows the rapid diffusion of fluid throughout the pad 42 the entire composite pad 26 can retain substantially as much fluid as a non-compressed pad unit of similar weight fairly reservoirs that retain body fluid numbers in local areas, but thanks to the faster and more efficient dissemination of the urine, there is much less leakage after urination and also a marked reduction in backflow, keeping the top layer 24 in a relatively dry state. In this way, the first and second cushions 25 40 and 42, respectively, cooperate to rapidly disperse the fluid volumes throughout the cushion 42 while maximizing utilization of the cushion material while maintaining the top layer 18 in a relatively dry state.

As noted above, the first pad 40 is relatively soft and may take the proper shape since it is relatively uncompressed. Accordingly, the first and second cushions 40 and 42, respectively, provide a cushion for the diaper, which cushion construction is soft and can assume the shape of the wearer such that comfort becomes as great as possible and an excellent fit of the diaper is provided. In addition, the pad of the present invention can be manufactured in a simplified manner by compressing the second pad 42 and then placing the first pad 40 against the second pad 42 during the diaper manufacture. The diaper is thus produced without the need to wet and dry the compressed areas, which would otherwise increase the complexity of the production and the associated costs.

35 Referring to FIG. 3, the cushion unit 21 shown in FIG.

1 be folded along a plurality of longitudinal fold lines to determine a diaper layout for the diaper. The diaper is thus folded along a pair of first fold lines

Claims (1)

An article according to claim 1, characterized in that the ratio of the density of the second cushion (42) to the density of the first 5 cushion (40) ranges from 1.5: 1 to approx. 7: 1, the ratio of the thickness of the first (40) to the second pad (42) is approx. 20: 1 to approx. 2: 1 and that the first pad (40) has a density of approx. 0.03 to approx. 0.07 g / cm 3 and the second pad (42) has a density of approx. 0.14 to approx. 0.22 g / cm 3. 10 15 20 25 30 35