FR2470590A1 - ABSORBENT ARTICLE PROVIDED WITH A MULTILAYER PAD - Google Patents

Abstract

THIS ARTICLE INCLUDES A SUPPORT SHEET 22 IMPERMEABLE TO FLUIDS, A COVER SHEET 24 PERMEABLE TO FLUIDS, A FIRST ABSORBENT PAD 40 ADJACENT TO THE COVER SHEET AND SHAPED BY A LOW-PACKED FIBROUS MASS AND A SECOND ABSORBING PAD BETWEEN IT 42 AND THE SUPPORTING SHEET AND HAVING AT LEAST ONE SIGNIFICANT PART WHICH IS DENER THAN THE FIRST BUFFER. THE AVERAGE SPACES BETWEEN THE FIBERS OF THE SECOND BUFFER ARE SIGNIFICANTLY LOWER THAN THOSE OF THE FIRST BUFFER SO THAT THE BODY FLUIDS THROUGH THE FIRST BUFFER ARE RAPIDLY TRANSMITTED BY THIS SECOND BUFFER TO LOCATIONS FAR FROM THEIR POINT OF APPLICATION THE COVER SHEET.

Description

The present invention relates to articles ab-

sorbents to be discarded after use.

  A large assortment of absorbent objects to throw away

  use has been proposed for the reception and retention of hu-

  body dies and secretions. Such articles, such as disposable diapers, sanitary napkins and the like, are normally composed of a fluid impervious backing sheet, a cover sheet, or top sheet, permeable to fluids, and an absorbent pad disposed between the support sheet and the cover sheet and constituted, for example, by finely ground wood pulp called in the technique of wood down. Although these articles are meeting with increasing success because they are discarded after use, certain problems remain linked to the use of absorbent pads and prevent them from being

fully satisfactory.

  First, it is necessary for the tampon to quickly spread and disperse body fluids from their point of application, to locations of the tampon distant from this point in order to reduce the saturation of the tampon in localized areas and ensure maximum use of full buffer capacity. Second, it is desirable for the tampon to preferentially retain body fluids in

  spaced areas of the cover sheet to reduce

  re at least wetting back through this sheet

  coverage and resulting user discomfort.

  Third, the tampon should be soft and should fit

  ter to the shape of the user to ensure a fit

  correct item and maximum user comfort.

  Finally, the tampon should be made using simplified manufacturing techniques to reduce the cost of items

  throw away after use for the consumer.

  In French patent application 7723598, filed on August 9, 1976 in the name of the inventor, the use is described in an absorbent article to be discarded after use which comprises a support sheet impermeable to fluids and a sheet

  upper permeable to fluids, an absorbent assembly

  laid with a weakly packed mattress adjacent to the cover sheet and a second mattress, or pad, arranged between

  the first mattress and the back support sheet, and

  both compressed regions formed throughout a large part of this second buffer and also. uncompressed regions adjacent to the compressed regions. Such a tampon is functionally superior to a product to be discarded after

  use of the conventional type with a single tampon.

  US Pat. No. 3,612,055 describes the construction of a single pad layer in which the surface which is not in contact with the top sheet is treated to form a film, of the paper type, in order to cause the spreading of the fluid on the rear face of

layer.

  The main object of the present invention is to provide

  an absorbent article of simplified construction which

  enhances dispersal and retention capabilities

fluids.

  The subject of this invention is an article which comprises

  a back support sheet of material impermeable to fluids

  des, a fluid permeable cover sheet and a first absorbent pad adjacent to the cover sheet

  and constituted by a weakly packed fibrous mass. The ar-

  the article has a second separate absorbent pad, disposed between the first pad and the back support sheet, and consisting of a mass of fibers having a compressed region

  which covers the whole of a significant part of the se-

  buffer buffer. The average spacings between the fibers of the se-

  cond buffer are significantly smaller than the spacings

  means between the fibers of the first tampon.

  According to a characteristic of the invention, the region com-

  award winning second pad absorbs body fluids from

  from the first buffer and quickly transmits these fluids

  at locations distant from the second buffer.

  According to another characteristic of the present invention

  tion dispersed fluids are retained in the region

  award of the second stamp in a space spaced from the sheet

the cover.

  Thus, an advantage of the invention is that the pads minimize return wetting by fluids

  body passing through the cover sheet and hand-

  keep the cover sheet in relatively good condition

dry during use of the article.

  Yet another feature of the present invention

  tion is that pads can be made in a

  re simplified and at a reduced cost.

  The characteristics of the invention will also emerge

  their following description of embodiments

  tion given by way of nonlimiting examples and represented in the appended drawings, in which: - FIG. 1 is a partial plan view, from the front, of an absorbent article according to the present invention which has been shown to be a disposable diaper;

  - Fig. 2 is a partial view, in section, approxi-

  matively along line 2-2 of FIG. 1; - Fig. 3 is a perspective view of the article of FIG. 1 after folding in a folded configuration

hollow; and -

  - Fig. 4 is a top plan view, with rear

  partial payment, of another type of diaper to be thrown away after use.

  In Figs. 1 and 2 to which we will now refer

  In addition, an absorbent article is shown, to be discarded after use,

  designated by the general reference 20 which is represented

  me in the form of a disposable diaper. Although,

  for convenience, the article of the present invention should be

  described below as being a disposable diaper, it is understood that the invention is also applicable to other absorbent articles to be discarded after use, such as

  only sanitary napkins and draw sheets. As depicted

  felt, the article or layer 20 comprises an absorbent assembly 21 which comprises a support sheet 22, impermeable to

  of, for example polyethylene, which forms an ar-

  23 of the absorbent assembly and which covers the rear surface 28 of a pad 26, a top sheet or cover sheet 24, permeable to fluids, for example of a non-woven material, which forms an important part of a

  front surface 25 of the absorbent assembly and an absorbent pad

  bant, designated by the general reference 26, which is arranged

  between the support sheet 22 and the cover sheet 24.

  As shown in Fig. 1 to which we will refer, the

  che 20 can include two adhesive tape fasteners 38 to allow the diaper to be secured around a child when it is put in place and the support sheet 22 can include transverse lateral marginal parts

  32 folded over the cover sheet 24 and fixed to it

  te sheet so that these marginal parts 32 cover

  the lateral parts of the buffer 26.

  As shown in Figs. 1 and 2, the absorbent pad

  bant 26 has a first absorbent pad or thickness

  adjacent to the cover sheet 24 and a second screen

  absorbent pon or thickness 42 disposed between the first sieve

  pon 40 and the support sheet 22. The pad 26 may include an upper wadding sheet 34 which covers a front surface 30 of the first thickness or upper thickness 40 and a rear wadding sheet 36 which covers a rear surface 28 of the second thickness or less

  42. In the embodiment shown, an over-

  rear face 41 of the first thickness 40 can be placed against a front surface 43 of the second thickness 42; in another embodiment, a fluid permeable sheet, such as a wadding sheet, may be interposed

  between the first thickness 40 and the second 42.

  The first thickness 40 is formed by a mass of

  weakly packed fibers, such as fine wood pulp-

  crushed called in the wood fluff technique. Although this first thickness 40 can be compacted if desired, it must be subjected to minimal compression so as to form a thickness before 40 which is soft and fluffy, with

  relatively large spacings between fibers.

  The density of the upper thickness 40 must be between approximately 0.03 g / cm 3 and approximately 0.07 g / cm 3, preferably between approximately 0.04 g / cm 3 and approximately 0.07 g / cm 3 and , more advantageously still, between approximately 0.06 g / cm3 and approximately 0.07 g / cm. The second thickness or lower pad 42 is also formed from a mass of fibers, such as finely ground wood pulp, such as thickness 40, but

  this second thickness is prepared, for example, by

  pressure or by any other suitable conventional means,

  to have a density between about 0.14 g / cm3 and about 0.22 g / cm 3, preferably between about 0.16 g / cm3 and about 0.20 g / cm and, more advantageously, Between

3 3

  about 0.18 g / cm and about 0.20 g / cm. Within the above density limits, it is desirable that the ratio of the density of the lower pad 42 to that of the upper pad be between about 1.5 / 1 and about 7/1,

  preferably between about 2/1 and about 5/1 and, more preferably

  again, between about 2/1 and about 4/1. Natural-

  Likewise, the density is determined simply from

  given weight of a measured volume (length x width x thickness-

  the latter being measured in the manner described above

below).

  The thicknesses of the pads can vary considerably-

  but, in general, they are combined to give a total thickness of between approximately 1 mm and approximately 40 mm with ratios between the thicknesses of the upper and lower pads, between approximately 50/1 and approximately 1/1, of 247059o

  preferably between about 20/1 and about 2/1 and, further

  again, approximately between 10/1 and approximately 4/1. All-

  the thicknesses indicated are based on effective measurements

  made with a load of 4.1 g / cm applied to the pad, since in the absence of such a applied load, due to the bulking and elasticity of the down pad, variable values would be obtained. The density values indicated are necessary for such thickness determinations. For diapers for children, the total thickness of the tampon is, obviously, generally lower than that of the pads of mattress pads and diapers for adults who suffer from incontinence of urine or sanitary napkins. Typical diapers for newborn children can have a tampon o whose total thickness is of the order of 1 mm to 6 mm,

  or of the order of 2 mm to 10 mm, depending on the model of the layer.

  For older babies, the total thickness of the tampon can be between about 2 mm and 8 mm, or between about 3 mm and 12 mm. The total thickness of a sanitary napkin pad can typically be between about 3 mm and 10 mm, or between about 4 mm and 20 mm or more, for example, between about 6 mm and 40 mm, in this case also,

  depending on the particular model of sanitary napkin used.

  In addition, it may be useful to indicate that the weights

  total wood fluff content in the pads can

  laugh considerably, as well as the thicknesses and di-

  buffer mensions. By way of example, it will be indicated that such weights can be, for example, of the order of 10 or

  g to about 100 g. Likewise also, generally

  rale, the ratio of the weight of the upper buffer to the weight of the lower buffer can be between approximately 2/1 and 1/2

  but preferably the two pads have the same weight, é-

  since this characteristic offers the greatest ease of manufacture. So, for example, we can form a single layer of wood down in a conventional way and then divide it in half, the part intended to form the thickness

  lower being compressed in the desired manner in accordance

ment to the present invention.

  When used, the diaper 20 is secured around a child using the adhesive tape fasteners 38. During urination, the urine passes through the cover sheet 24 and enters a localized part of the first pad 40 and, due to the relatively small spacings between the fibers of the second compressed pad 42, the fluids are rapidly absorbed out of the first pad 40 by the second pad 42. In addition, the compressed pad 42 rapidly transmits the fluids to the parts of the pad who

  are distant from the point of application of urine to the diaper.

  Although a relatively large amount of raised material

  teuse was compressed to produce tampon 42 and that

  if the latter has a smaller fluid retention capacity than the pad 40 due to the relative dimensions of the spacings between their respective fibers, the spreading

  or the rapid dispersion of the fluid throughout the entire

  pon 42 allows the global composite buffer 26 to retain pra-

  as much fluid as a non-absorbent assembly

  of equivalent weight, in much the same way as tanks that hold body fluids in different locations, but because of the faster and more efficient dispersion of urine, there is less leakage after each urination and also a marked reduction in back wetting, which keeps the top sheet

  24 in a relatively dry state. In this way, the first

  mier tampon 40 and the second tampon 42 cooperate to disper-

  quickly seal fluids throughout the second pad

  while ensuring maximum use of the material ab-

  sorbent and holding the top sheet 24 in a

relatively dry state.

  As previously indicated, the first buffer 40 is

  relatively soft and adaptable since it is relatively

  hardly compressed. Consequently, the first and second pads 40 and, respectively, 42 provide for the layer an absorbent structure which is soft and adapts to the shape of the user so as to ensure maximum comfort and to allow an excellent adjustment of layer. Furthermore, the tampon 26 of the present invention can be made in a simplified manner by compressing the second tampon 42 and then placing the first tampon 40 against the second tampon 42 during manufacture of the diaper. So the layer is

  manufactured without the need to wet and dry

  expensive compressed areas, which would otherwise increase the

  complexity and cost of manufacturing.

  As shown in Fig. 3, the absorbent assembly

  21 can be folded along several fold lines along

  gitudinal to give the layer a fold configuration

  hollow. So the layer is folded along a pair of pre-

  fold lines 50 to delimit a central panel

  52 extending longitudinally and along a pair of se-

  fold lines 54 to form a pair of first panels 56 extending longitudinally and delimited by

  fold lines 50 and 54 and a pair of exterior panels

  laughers 58 starting from the second fold lines 54.

  The layer 60 represented in FIG. 4 has a configuration

  hourglass-shaped ration with a region of

  leg 62 and four parts of greater width forming

  ears 64, 66, 68 and 70. The layer has a sheet

  the support 72, made of polyethylene or the like, and a top sheet 74, in the same way as the layer in the form of a hollow ply. An absorbent assembly similar to the pads 26,

  40 and 42 of the pleated layer is disposed in

  be the backing sheet and the top sheet. Leaves

  wadding 77, similar to sheets 34 and 36 of the pleated layer, can be used, as in this pleated layer. The absorbent assembly and also the cotton sheets have smaller dimensions, as shown, than the support and upper sheets, which have

both have the same dimensions.

  In a test carried out on a sample of 106 users

  sators with non-identifiable products comprising a first standard tampon layer (down tampon

  wood of uniform density 0.1. g / cm weighing 36 g.

  - dimensions of the pad 300 x 409 mm as well as a second two-layer buffer layer of the present invention,

  which had the same dimensions and the same weight as the first

  layer but in which the upper pad had

  a density of 0.06 g / cm and the second buffer or buffer

  With a density of 0.2 g / cm, the following results were obtained Prefer the layer with two layers of down Prefer the current type layer No preference Overall preference Drier posterior Resistance Absorption Overall fit Adjustment around the thighs Thickness B case of leaks where the layer could still have absorbed if it had been

15

required Report B B

+ 1.49 +

+ 1.36

+ 1.65+

+ 1.38

+ 1.02

- 1.08

+ 1.44

rg Um n. % 0 it

  The overall preference ratio of 1.49 is statisti-

  only equivalent to a preference of +2 sigma for the cou-

  two-ply pad cheek and indicated at a level of

  95% confidence 5, that a majority of consumers prefer

  the two-ply buffer layer to the

a single classic tampon.

Claims (9)

RESELL ICAT IONS   1 - Absorbent article to be discarded after use comprising a support sheet (22, 72) made of a material impermeable to fluids and a cover sheet (24; 74) permeable to fluids, characterized in that it comprises a first pad   absorbent (40) adjacent to the cover sheet and   formed by a loosely packed fibrous mass and a second absorbent pad (42) disposed between the first pad and the support sheet, and constituted by a fibrous mass which is denser than the first pad on at least part of this second pad in which the average spacings between the fibers are significantly smaller than the average spacings between the fibers of the first tampon, and which rapidly transmits the fluids of the body to locations distant from the second tampon so that they are retained therein in a   spaced location of the cover sheet.   2 - absorbent article according to claim 1, charac-   terized in that the combined thickness of the first and second   pads (40, 42; 75) is between about 1 mm and about 38 mm.   3 - absorbent article according to claim 1, charac-   terized in that the ratio of the density of the second pad (42) to that of the first pad (40) is of the order from about 1.5 / 1 to 7/1.   4 - absorbent article according to claim 3, charac-   terrified in that the density ratio of the two   buffers is between about 2/1 and 4/1.   - Absorbent article according to one of the claims   1 to 4, characterized in that the denser part of the second   pad (42) extends to the transverse and end edges mite from the second buffer.   6 - absorbent article according to one of claims   1 to 5, characterized in that it includes a cotton wool sheet   upper (34; 77) which covers a front surface of the first mier tampon (40).   7 - absorbent article according to one of claims   1 to 6, characterized in that it comprises a rear wadding sheet (36, 77) which covers a rear surface of the second pad (42).   8 - absorbent article according to claim 7, ca-   characterized in that the back wadding sheet (36; 77) is compressed.   9 - absorbent article according to claim 3, charac-   terized in that the first pad (40) has a density between about 0.03 g / cm3 and 0.07 g / cm3 and in that   the second buffer (42) has a density between 3 3 about 0.14 g / cm and 0.22 g / cm   - Absorbent article according to claim 9, charac-   terized in that the ratio of the thickness of the first pad (40) to the thickness of the second pad is of the order of 20/1 at 2/1.   II - Absorbent article according to claim 10,   characterized in that it has a configuration in a box pleat orien- lengthwise tee.   12 - absorbent article according to claim 10,   characterized in that it has a general hourglass shape and   includes elastic means in the transverse region-   central to ensure better adaptation around   legs of the person using it.