IE45552B1

IE45552B1 - Absorbent articles

Info

Publication number: IE45552B1
Application number: IE1658/77A
Authority: IE
Original assignee: Colgate Palmolive Co
Priority date: 1976-08-09
Filing date: 1977-08-08
Publication date: 1982-09-22
Also published as: FR2361076B1; AU506555B2; FR2361076A1; IT1079291B; ZA773902B; AU2660077A; AT369630B; DK325177A; GR66821B; GB1547524A; PT66811A; ATA572877A; NL7707861A; JPS5331392A; MX149263A; IE45552L; CA1105689A; PT66811B; ES238914Y; BR7704995A

Abstract

The absorbent article has a water-impermeable outer layer (14), a water-permeable inner layer (18) and a first absorbent inlay (28) located next to the water-permeable inner layer (18). The first absorbent inlay (28) comprises a fibrous velvety material. A second absorbent inlay (30) is arranged between the first absorbent inlay (28) and the water-impermeable outer layer (14). This second inlay (30) comprises a fibrous velvety material having embossed sites (50) extending through the greater part of the second inlay (30). The uncompressed areas (52) lie next to the embossed sites (50). The fibre distances of the embossed sites (50) are considerably smaller than the average fibre distances in the first inlay (28). The embossed sites (50) thus quickly lead body fluids to more remote parts in the second inlay (30) in such a way that the body fluid is retained in regions remote from the inner layer (18). The absorbent article is especially suitable for nappies, sanitary towels and clinical substrates.

Description

The present invention relates to disposable absorbent articles.

Various disposable absorbent articles have been * proposed for use in receiving and. retaining body fluids. j 5. Such articles, e.g. disposable diapers, have normally comprised a fluid-impervious backing sheet, a fluid-impervious ' top or cover sheet and an absorbent pad between the backing and cover sheets.

There are certain problems that remain associated with 10. the absorbent pads which have prevented such absorbent articles from being totally satisfactory.

First, it is necessary that the pads rapidly spread . body fluids from the point of application toward remote parts of the pads in order to minimise pad saturation in ; 15. localized areas and make maximum use of the pad capacity.

Second, it is desirable that the pads preferentially retain the body fluids at locations spaced from the cover sheet in order to minimize back wetting through the cover sheet with attendant discomfort to the wearer. Third, the pads i . should be soft and conformable to the shape of the wearer J in order to provide a proper fit of the articles and : ‘ maximum comfort. Finally, the pads should bs easy to , make so that the cost of the disposable articles to the consumer is not unacceptably high.

. An.object of the invention is the provision of an I absorbent article of simple construction having improved fluid dispersing and retention capabilities, ι According to the present invention a disposable absorbent article comprises a fluid-impervious backing . sheet, a fluid-pervious cover sheet, a first absorbent •245552 pad adjacent the cover sheet and comprising a loosely formed fibrous mass, and a separate second absorbent pad between the first pad and the backing sheet, the second pad comprising a mass of fibres having compressed regions , all interconnected, . /extending throughout a substantial part of the second pad and having relatively uncompressed areas adjacent those regions, the average interfibre spacings in the regions being substantially less than the average interfibre spacings in the areas and in the first pad; interconnected , The/regions of the second pad absorb body fluids from the first pad and rapidly transmit the fluids to remote locations of the seoond pad. The dispersed fluids are retained in the areas of the seoond pad. Thus the regions and areas of the second pad cooperate to disperse and retain . body fluids in the second pad at a location spaced from the cover sheet, minimizing back flow of the body fluids from the absorbent pad towards the cover sheet/and maintaining the cover sheet in a relatively dry condition during use of the article.

The pads can be soft and conformable to the shape of go. the.wearer due to separation of the regions by the areas in the second pad.

The pads can be made in a simple manner and at low cost. - . · .

The invention may be performed in various ways, and a . specific embodiment, a disposable diaper, will now be described by way of example with reference to the accompanying drawings, in which: .‘ Figure 1 is a fragmentary top plan view of the disposable diaper with parts broken away to show the internal 50. construction; - 3 45552 Figure 2 is a fragmentary cross-section taken along the line 2-2 of Fig. 1; and Figure 3 is a perspective view of. .the diaper folded into a box-pleat configuration.

, . Although for convenience the invention is described as applied to a disposable diaper, it is applicable to other disposable absorbent articles, such as sanitary towels, Referring to Figures 1 and 2,. there-is shown a disposable . diaper 10 comprising an absorbent pad assembly 12.having a fluid-impervious backing sheet 14, such as a sheet of polyethylene, defining a back surface 16 of the pad assembly, a fluid-pervious cover sheet 18, such as a piece of pervious nonwoven material, defining a substantial . portion of a front'surface 20 of the pad assembly, and an absorbent pad 22 between the backing sheet 14 and the cover sheet 18. With-reference to Figure 1, the diaper 10 may have a pair of tape fasteners 24 for securing it about an infant, and the backing sheet 14 may have lateral side 2Q. margins 26 folded over and secured to the cover sheet 18 such that the margins 26 overlie side portions of the pad' 22.

As shown in Figs. 1 and 2, the absorbent pad 22 has a first absorbent pad or layer 28 adjacent the cover sheet . 18, and a second absorbent pad or layer 30 between the > first pad 28 and the backing sheet 14. The pad 22 may have a top wadding sheet 32 covering a front surface 34 of the first pad 28, and a’back wadding sheet 36 covering a back surface 38 of the second pad 30. In one form, as shown, . a'back surface 40 of the first pad 28 may be placed - 4 45552 directly against a front surface 42 of the second pad 30, or, in an alternative form (not shown), a fluid-pervious intermediate sheet, such as a wadding sheet, may he interposed between the first and second pads 28 and 30, . respectively.

The first pad 28 is made from a loosely formed mass of fibres, such as comminuted wood pulp termed fluff in the art. Although the first pad 28 may be compressed, -if desired, its degree of compression should be slight so 10. that this pad is soft and fluffy with relatively large interfibre spacings. As will be seen below, the second lower pad 30 is also made from a mass of fibres, such as comminuted wood pulp.

In a suitable form, before final compression of the 15. pad 22, the first pad 28 may have a thickness of approximately 161 mils (0.409 cm) + 40 mils (0.102 cm) and a density of approximately 0.037 + 0.009 g/cm^ as measured under the relatively slight compression of 2.1 g/cm2, and a thickness of approximately 72 mils (0.183 cm) . +18 mils (0.046 cm) and a density of approximately 0.083 + 0.021 g/vu? as measured under a larger compression of 51.2 g/cm2. The density of the pad is calculated by dividing the weight of the pad sample by its volume.

Before final compression, the lower second pad 30 may . have a thickness of approximately 63 mils (0.160 cm) + mils (0.041 cm) and a density of approximately 0.053 + 0.013 g/crn^ as measured under the slight compression of 2.1 g/cm , and a thickness of approximately 18 mils (0.046 cm) + 5 mils (0.013 cm) and a density of . approximately 0.108 + 0.027 g/crn^ as measured under the - 5 larger compression of 51.2 g/cm . After final compression of the pad 22, the first pad 28 may have a thickness'of approximately 89 mils (0.226 cm) + 22 mils (0.056 cm) and a density of approximately Ο.Ο63 + 0.016 g/cm^ p .5. as measured under the slight compression of 2.1 g/cm, and a thickness of approximately 49 mils (0,124 cm) + mils (0.030 cm) and a density of approximately 0.115 + 0.029 g/cm^ as measured under the larger compression .of 51.2 g/cm2. After final compression of the pad 22, . the.lower.second pad 30 may have a thickness of approximately mils (0.094 cm) + 9 mils (0,023 cm) and a density of approximately 0.083 + 0.021 g/cm^ as measured under the slight compression of 2.1 g/cm2, and a thickness of approximately 10 mils (0.025 cm) + 3 mils (0.008 cm) . and a density of approximately 0.148 + 0.037 g/cm^ as measured under the larger compression of 51.2 g/cm*1.

After final compression of the pad 22, the combined pads • . 28 and 30 may have a thickness of approximately 112 mils (0.284 cm) + 28 mils (0.071 cm) and a density of . approximately 0.074 + 0,019 g/cm^ as measured under the slight compression of 2.1 g/cm2, and a thickness of _ .· approximately 57 mils (0.145 cm) + 14 mils (0.036 cm) and a density of approximately 0.124 + 0.031 g/cm^ as , · p ‘ measured under the larger compression of 51.2 g/cm . interconnected . The second pad 30 has/compressed regions 50, such as intersecting lines of compression extending throughout a substantial part of the second pad between side and end edges of the pad. In a preferred form, the regions 50 are recessed from and are located generally midway . between the opposed surfaces 42 and 3S of the second pad 30. - 6 455S2 The second pad 30 also has relatively uncompressed areas 52 adjacent the regions 50, the average interfibre spacings in the areas 52 being slightly less than or approximately equal to the average interfibre spacings in . the first pad 28. Thus, the average interfibre spacings in the compressed regions 50-of the second pad are substantially less than the average interfibre spacings in the areas 52 of the second pad 30 and in the first pad 28. ' In the embodiment shown, the regions 50 define . a diamond-like configuration of the areas in the second pad 30, the areas 52 being separated by the regions 50, and the regions 50 extending in a connected pattern throughout the pad. If desired, the back wadding sheet .36 may be compressed in regions 50' corresponding to the . regions 50 of the second pad 30, as shown in Fig. 1, or the back wadding sheet 36 may be placed against the back surface 38 of the second pad 30 after the second pad 30 has been compressed, such that the back wadding sheet 36 is free of compressed regions, as shown in Figure 2.

. In use, the diaper 10 is secured about an infant by the tape fasteners 24. During voiding, urine passe^ through the cover sheet 18 into a localized portion of the first pad 28, and due to the relatively small interfibre spacings of the regions 50 in the second pad 30, the fluids . are rapidly absorbed from the first pad 28 by the regions interconnected of the second pad 30. Also, the/compressed regions 50 rapidly transmit the fluids along the regions or lines 50 to pad portions which are remote the point of urine application to the diaper. Although a large amount of . fluff material has been compressed in the pad regions 50, - 7 . 45SSS these regions have a smaller fluid holding capacity than the areas 52 due to the smaller interfihre spacings in the regions. Accordingly, the body fluids pass from the regions 50 when saturated into the uncompressed areas 52 . of the second pad 30. Since the areas 52 have a relatively large fluid holding capacity, they act like reservoirs which retain the body fluids in localities spaced from the point of urine application to the diaper and at a location beneath the first pad 28 spaced from the . top sheet 18, in order to reduce back -flow - of body fluids froa the pad 22 and maintain the top sheet IS in a relatively dry condition. In this maimer, the first and second pads 28 anti. 30, respectively, cooperate to disperse fluids rapidly throughout the second pad 30 . while making maximum use of the pad material and maintaining the top sheet 18 in a relatively dry State.

As previously indicated, the first pad 28 and the pad areas 52 are relatively soft and conformable since they are relatively uncompressed. Accordingly, the first and . second pads 28 and 30, respectively, provide a pad structure for the diaper which is soft and conformable to. the shape of the wearer in order to improve comfort and facilitate a good fit of the diaper.

The pad 22 can be made in a simple manner by . oo'mpressing the seoond pad 30 in the regions 50, and by then placing the first pad 28 against the second pad 30 during manufacture of the diaper.' Thus, the diaper «ay be . , made without the necessity of wetting and drying the compressed regions which would otherwise add to the , complexity and cost of manufacture. - 8 45552 Referring to Figure 3, the pad assembly 12 of Figure 1 may he folded along a plurality of longitudinal fold lines to define a box-pleat configuration of the diaper. The diaper is folded along a pair of first fold lines 54 to . define a central panel 56 and along a pair of second longitudinal fold lines 58 to define a pair of intermediate side panels 60 between the fold lines 54 and 58 and a pair of outermost panels 62 extending from the second fold lines 58 and overlying the intermediate panels.

Claims

1. A disposable absorbent article comprising a fluid-impervious backing sheets a fluidpervious cover sheet, a first absorbent pad adjacent 5 the cover sheet and comprising a loosely formed fibrous mass,- and a separate second absorbent pad between the first pad and the backing sheet, the second pad comprising all interconnected a mass of fibres having compressed regions /extending throughout a substantial part of the second pad and 10 having relatively uncompressed areas adjacent the regions, the average interfibre spacings in the regions being less than the average interfibre spacings in the areas and in 'the first-pad.

2. An article as claimed in Claim 1 wherein 15 the thickness of the second pad is approximately 37 mils (0.094 cm) + 9 mils (0.023 cm) as measured under slight compression.

3. An article as claimed in Claim 1 or Claim 2 wherein the regions separate areas in the second 20 . pad from one another.

4. \ . An article as claimed in any of the - 10 45553 preceding claims wherein the regions extend to side and end edges of the second pad.

5. An article as claimed in any of the preceding claims including a top wadding sheet covering 5 a front surface of the first pad.

6. An article as claimed in any of the preceding claims including a hack wadding sheet covering a hack surface of the second pad.

7. An article as claimed in Claim >6 wherein 10 the back wadding sheet is compressed in regions corresponding to the regions of the second pad.

8. An article as claimed in any of the preceding claims wherein the regions are recessed from opposed surfaces of the second pad. U

9.. An article as claimed in Claim ® wherein the regions are located generally midway between the opposed surfaces of the second pad.

10. A disposable absorbent article substantially as described with reference to the accompanying drawings.