FR2699812A1 - Disposable and absorbent hygienic pad - Google Patents

Abstract

The pad, e.g., a nappy, comprises a layer (3) of an absorbent material on an impermeable backing layer (2), shaped to form a central section (8) which goes between the legs, and two ends (9,10) forming front and rear panels, equipped with waist fixings (14). The absorbent layer (3) is basically rectangular in shape, while the backing layer has four aeration apertures (15) formed by zones which are impermeable to liquids but permeable to gases two in the front panel and two in the rear one. The nappy also has two lengthwise air circulation strips, made from a moisture resistant and gas-permeable material, which pass along the sides of the absorbent pad from one end to the other and link the aeration apertures on the same side.

Description

DISPOSABLE ABSORBENT HYGIENE ARTICLE PROVIDED WITH VENTILATION TUNNELS
The present invention relates to a disposable absorbent hygiene article, in particular a disposable diaper for young children or for adult incontinence, which comprises an absorbent pad placed on an outer support sheet, impermeable to liquids. It relates more particularly to an improved hygiene article allowing a good gas exchange between the interior and the exterior, when said article is positioned on the user.

 Hygiene items of this type are designed to ensure a good seal at the thighs of the user, so as to avoid the risk of leakage of urine along the leg.

However, this results in risks of skin irritation for the user where the wet absorbent cushion is continuously in contact with the skin thereof.

 To overcome this drawback, it has already been proposed to use as an outer support sheet a material which is not only impermeable to liquids but also permeable to vapor. Thus, thanks to this permeability, it is possible to obtain a gas exchange between the inside and the outside of the hygiene article and therefore a reduction in the moisture content of the ambient prevailing inside said article.

 However, this radical solution has a major drawback, namely the price of such a material which is both impermeable to liquids and permeable to vapor.

 Document EP O 109 126 proposes a simplified solution making it possible to ensure the gas exchange between the inside and the outside of the absorbent article. In this solution, only the sealing flaps are more vapor permeable per unit area than the actual support sheet. These sealing flaps consist of the portions of the article which wrap around and are in contact with the wearer's leg normally in the thigh region of the wearer.

 Document US 4,887,602 proposes another simplified solution allowing this gas exchange to be ensured. According to this solution, the article has ventilation openings which are located in the areas between the absorbent pad and the lateral and transverse edges of the article.

 However, according to the applicant, in each of these known solutions, the gas exchange is imperfect, being limited to a specific area of the article.

 The goal that the applicant has set is to provide a disposable absorbent hygiene article, in particular a diaper, which is breathable, that is to say which allows a good gas exchange (water vapor and air) between inside and outside of the article, and which does not have the aforementioned drawback. More specifically, the applicant is looking for an article which further improves user comfort.

 This object is perfectly achieved by the disposable absorbent hygiene article, in particular a diaper, according to the invention.

It is an article which comprises, in a known manner, an absorbent cushion disposed on an outer support sheet which is impermeable to liquids; moreover, said article is made in the longitudinal direction of a central part which corresponds to the crotch area and of two end parts one front and the other rear which correspond to the positioning and fixing zones around the size of the user.

 Characteristically according to the invention, the absorbent pad being of substantially rectangular shape, the outer support sheet has four ventilation openings, which consist of four liquid impermeable and gas permeable zones, two in the front end part and two in the rear end part, said openings being located on either side and at least along the absorbent pad; in addition the article comprises a) two longitudinal bands of air circulation, made of a hydrophobic and gas-permeable material, each band being fixed by its first longitudinal edge to the right of the longitudinal side of the absorbent pad, by its second longitudinal edge and by its two edges transverse to the external contours of the support sheet so that it covers towards its two ends the two ventilation openings situated on the same side of the absorbent pad, b) and means of deformation of said longitudinal circulation bands d air capable of deforming them so that they form, when the article is positioned on the user, two internal tunnels connected to the ventilation openings.

 Thus, unlike the known embodiments, the principle of the invention is based on capturing the vapor emitted in the immediate vicinity and all along the absorbent pad and on its evacuation thanks to an aeration tunnel which opens into the extreme parts of the article.

 The ventilation openings are, in the outer support sheet, areas which are both impermeable to liquids and permeable to gases. They can be obtained in different ways.

 According to a first variant, each ventilation opening is obtained by making a cut and covering of said cut in the outer support sheet with a material impermeable to liquids or hydrophobic and breathable.

 This covering material may in particular be a hydrophobic nonwoven, a hydrophobic foam or a hydrophobic microporous film.

 According to a second variant, the ventilation opening is obtained by localized perforations of small diameter in the outer support sheet.

 Preferably, the means for deformation of a longitudinal strip of air circulation consist of an elastic element which is placed under said longitudinal strip and which is fixed to the article in the end portions and beyond the ventilation openings, in the stretched state when said article is flat. So when the article is shaped, in the position it has on the user, the retraction of the elastic element causes the lifting of the corresponding longitudinal strip above the support sheet and thus gives off an internal volume. constituting the internal ventilation tunnel.

 Advantageously, each longitudinal strip of air circulation has, in the central part, a width which is between two and four times the width of a ventilation opening, the inner longitudinal edge of said strip being fixed along a line passing through immediate proximity of the two ventilation openings located on the same side of the absorbent pad. Thanks to this particular arrangement, it is possible, during the manufacture of the hygiene article according to the invention, to form a longitudinal fold in the circulation band, this fold being located, in the central part, approximately at the two third of the width of said strip and the elastic deformation element being fixed in the stretched state in the fold thus formed.

 In the case of an article which comprises in a known manner on the one hand an inner sheet permeable to liquids which covers the absorbent pad and which is fixed on the support sheet and on the other hand elastic crotch elements which are arranged longitudinally towards the two outer edges of the central part, preferably according to the invention, each longitudinal strip of air circulation is fixed on the one hand to the inner sheet to the right of the outer edge of the absorbent pad and on the other hand on the support sheet, in particular above the elastic crotch elements. The fact that the air circulation strip is fixed along one of its longitudinal edges to the right of the outside edge of the absorbent pad allows '' increase the tunnel effect insofar as the fixing lines of the two edges of the ventilation strip are not located in the same plane.

 In the case of a disposable absorbent hygiene article having, in known manner, an hourglass shape with two lateral notches at the level of the central part, preferably according to the invention, each longitudinal strip of air circulation has the same external contour in the form of a half-hourglass as the longitudinal part of the support sheet extending beyond the absorbent pad and is fixed on their common external contours.

 The present invention will be better understood on reading the description which will be given of an embodiment of a diaper with ventilation tunnels, illustrated by the appended drawing in which - FIG. 1 is a representation of the diaper with two ventilation tunnels in the stretched state according to a plan view, - and Figure 2 is a half-view in section along the axis Il II of Figure 1.

 The diaper 1 which is illustrated in Figure 1 consists in known manner of an outer support sheet 2, an absorbent pad 3 and a cover sheet 4, covering the absorbent pad 3 and ensuring its attachment on the backing sheet 2.

 The support sheet 2 is impermeable to liquids. It is for example an impermeable plastic film such as polyethylene. It can also be formed in a composite manner from an impermeable plastic film 5, in particular polyethylene, and from a nonwoven sheet 6. In the example shown in FIG. 2, it is the nonwoven 6 which is turned towards the inside of the diaper 1, but it can just as easily be the reverse arrangement.

 The absorbent pad 3 has a substantially rectangular shape for the reasons which will be explained below.

It is composed for example of cellulose fluff pulp, possibly containing a super absorbent polymer.

 The absorbent pad 3 is glued to the support sheet 2 and covered with the cover sheet 4 which is permeable to liquids, being for example a non-woven veil.

 The support sheet 2 has a general hourglass shape, with two notches 7, lateral and opposite, delimiting in the longitudinal direction of the diaper 1 a central part 8 and two end parts 9 and 10. The central part 8 corresponds to the crotch area, that is to say the area of the diaper 1 which will be directly in contact with the user's leg at the thigh; the end portions 9, 10 correspond to the zones of the diaper 1 used for positioning and fixing it around the waist of the user. The extreme part 9, which is located towards the top of FIG. 1, corresponds to the front part of the diaper because it is on the front of the user, while the other extreme part 10, at the bottom of Figure 1 corresponds to the rear part since it is located on the back of the user.

 The central part 8 has a width which is less than that of the two front and rear end parts 9, 10.

 The structure of the outer support sheet 2 can have different embodiments when it is formed in a composite manner from an impermeable film 5 and from a nonwoven fabric. For example, the impermeable film 5 can be a rectangular film having the same width as the central part 8. For example the nonwoven sheet 6 can be formed from two strips, each of which being glued by one of its longitudinal edges to the corresponding edge of the plastic film, while that its other edge has a notch 7, as shown in Figure 1. In these two examples the parts of the support sheet 2 which are located towards the four corners of the diaper 1, in the end parts 9 and 10 of these consist only of the nonwoven sheet 6.

 The cover sheet 4 has the same length as the support sheet 2, but has a narrower width, which is slightly greater than that of the absorbent pad 3 so as to cover the top 11 as well as the two lateral sides 12 of the absorbent pad 3 and to be glued longitudinally on the support sheet 2 along said absorbent pad 3.

 The support sheet 2 and the cover sheet 4 are joined by gluing at their longitudinal ends, at the end portions 9 and 10 of the diaper 1.

 The latter also comprises longitudinal elastic elements 13 which are fixed in the stretched state to the support sheet 2, at least in the central part 8.

 Two adhesive fasteners 14 are fixed laterally, on either side of the rear end part 10. They are intended to be applied to the front end part 9, once the diaper 1 is placed in position on the user. .

 Typically according to the invention the support sheet 2 has in the end parts 9, 10 of the diaper 1 four gas permeable zones called ventilation openings 15. These are arranged symmetrically with respect to the axis longitudinal DD 'of the diaper 1, on either side of the absorbent pad 3.

 The particularity of these four ventilation openings 15 is that they are both impermeable to liquids and permeable to gases (air and water vapor). This can be achieved in different ways. In a first way the ventilation opening 15 results from a cut formed in the support sheet 2 and from the covering of said cut with a hydrophobic or liquid impermeable material but permeable to gases such as a hydrophobic foam or a non -woven hydrophobic or a hydrophobic microporous film; it may in particular be a microporous nonwoven based on microfibers, of the melt-blown or spun type.

In a second way, the ventilation opening 15 results from a series of perforations of small diameters, made locally in the zone corresponding to said ventilation opening 15. The perforations in question will have a diameter large enough to allow the gas exchange, but sufficiently weak to prevent the passage of liquid.

 Typically according to the invention the two ventilation openings 15 a and 15 b, located on the same side of the absorbent pad 3 respectively in the front end part 9 for 15 a and in the rear end part 10 for 15 b are connected by an internal ventilation tunnel 16. The same is true for the two other ventilation openings which are also connected by a second ventilation tunnel 16.

 Each of the ventilation tunnels 16 is made up of a longitudinal strip 17 of a hydrophobic and gas-permeable material. It is for example a hydrophobic nonwoven veil. The two longitudinal strips 17, said to be of air circulation, are fixed symmetrically above the support sheet 2 on either side and along the absorbent pad 3 so that each of them overlaps towards its longitudinal ends with a on the one hand the front ventilation opening 15 a and on the other hand the rear ventilation opening 15 b.

 In a specific embodiment, each of the hydrophobic nonwoven webs, constituting an air circulation strip 17, is disposed on one of the longitudinal parts of the support sheet 2 which extends beyond the longitudinal flank 12 of the absorbent pad 3; this nonwoven web is bonded to said longitudinal part of the support sheet 2 along their common external contour, including above the longitudinal elastic elements 13 located at least in the central part 8.

 As clearly appears in FIG. 2, each air circulation strip 17 has a width sufficient to be folded back on itself, so as to form a longitudinal fold 18. An elastic element 19 is provided in the stretched state, when the diaper 1 is flat, between the two faces 23, 24 of the fold 18 along the fold 25. This elastic element 19 is fixed by gluing to the air circulation strip 17 inside said fold 18, the latter being itself fixed by gluing to the cover sheet 4 beyond the transverse edges 27 of the absorbent pad.

 When the diaper 1 is put in place, the elastic element 19 retracts, causing the corresponding air circulation band 17 to rise. This lifting causes a deformation which creates an air circulation passage to the inside the space 20 located between the two faces 23, 24 of the fold 18 formed in the strip 17 and the support sheet 2. There is therefore created an aeration tunnel 16 which extends longitudinally along the longitudinal flank 12 of the absorbent pad 3 and which favors the circulation of the air entering or leaving through the ventilation openings 15 and consequently ensuring good ventilation of the interior of the diaper 1 all along the absorbent pad 3.

 In the embodiment illustrated in FIG. 2, the inner longitudinal edge 21 of the air circulation strip 17 is glued to the cover sheet 4 in line with the corresponding side 12 of the absorbent pad. This particular arrangement allows an amplification of the volume representing the interior space 20 of the tunnel 16 during the retraction of the elastic element 19. Furthermore in this case and the fact that the air circulation strip 17 is made of a material hydrophobic, the face of the air circulation strip 17 which is between the internal longitudinal edge 21 and the fold 25 forms a lateral sealing flap 22 which rises above the absorbent pad 3 and which is opposed at the transverse passage of liquid.

 This double effect, of ventilation tunnel and sealing flap is preferably obtained when the air circulation strip 17 has, in the central part 8, a width which is between two and four times that of a ventilation opening 15.

 The invention is not limited to the embodiment which has been described above by way of non-exhaustive example. In particular in the example illustrated in FIG. 1, the ventilation openings 15 have a shape substantially in the quarter of an ellipse.

This form is not limiting. It is up to a person skilled in the art to give the ventilation openings 15 the suitable shape and location provided that they are located in the front 9 and rear end parts of the diaper 1 on either side. and at least along the absorbent pad 3.

 In particular, in the case where the absorbent cushion 3 is not strictly rectangular, the shape and the location of the ventilation openings would be adapted accordingly: for example in the case of a cushion having transverse extensions in the end portions , the ventilation openings could be located in the area adjoining both the longitudinal edge of the cushion and one of the transverse extensions.

 It is moreover not excluded to arrange the ventilation openings 15 partly under the absorbent pad 3 this would also make it possible to ensure a certain ventilation inside said pad.

Claims (10)

1. Disposable absorbent hygiene article, in particular a diaper, comprising an absorbent cushion (3) disposed on an outer support sheet (2) impermeable to liquids, said article being formed in the longitudinal direction of a central part (8) which corresponds to the crotch zone and two end parts, one front (9) and the other rear (10) which correspond to the positioning and fixing zones around the waist of the user, characterized in that, the absorbent pad (3) being of substantially rectangular shape, the outer support sheet (2) has four ventilation openings (15), which are four zones impermeable to liquids and permeable to gases, two in the extreme part front (9) and two in the rear end part (10), said openings (15) being located on either side and at least along the absorbent pad (3), and in that it comprises a) two longitudinal air circulation strips (17), made s in a hydrophobic and gas-permeable material, each strip (17) being fixed by its first longitudinal edge (21) in line with the longitudinal flank (12) of the absorbent pad (3), by its second longitudinal edge and by its two edges transverse to the outer coSixrs of the support sheet (3) so that it covers towards its two ends the two ventilation openings (15a, 15b) located on the same side of the absorbent pad (3), b) and deformation means (19) of said longitudinal bands (17) of air circulation capable of deforming them so that they form, when the article is positioned on the user, two internal tunnels (16) connected to the openings of ventilation (15). 2. Disposable absorbent hygiene article according to claim 1 characterized in that, each ventilation opening (15) is obtained by making in the outer support sheet (2) a cut and covering of said cut with an impermeable material liquid or hydrophobic and breathable. 3. Disposable absorbent hygiene article according to claim 2 characterized in that the covering material is a hydrophobic nonwoven, a hydrophobic foam or a hydrophobic microporous film. 4. Disposable absorbent hygiene article according to claim 1 characterized in that, each ventilation opening (15) is obtained by localized perforations of small diameter in the outer support sheet (2). 5. Disposable absorbent hygiene article according to one of claims 1 to 4 characterized in that the means for deformation of a longitudinal band of air circulation (17) consist of an elastic element (19) which is placed under said longitudinal strip (17) and which is fixed to the article in the end portions (9, 10) and beyond the ventilation openings (15a, 15b), in the stretched state when said article (1) is flat. 6. Disposable absorbent hygiene article according to one of claims 1 to 5 characterized in that each longitudinal strip of air circulation (17) comprises a fold (18) longitudinal. 7. Disposable absorbent hygiene article according to claim 6 characterized in that each longitudinal strip of air circulation (17) has, in the central part (8), a width which is between two and four times the width d '' a ventilation opening (15), the inner longitudinal edge (21) of said strip (17) being fixed along a line passing in the immediate vicinity of the two ventilation openings (15) located on the same side of the absorbent pad (3). 8. Disposable absorbent hygiene article according to claim 7 characterized in that the elastic element (19) is placed between the two faces (23, 24) of the fold (18), along the fold (25). 9. Disposable absorbent hygiene article according to one of claims 1 to 8 characterized in that, being an article which comprises on the one hand a cover sheet (4) permeable to liquids which covers the absorbent cushion (3) and which is fixed on the support sheet (2) and on the other hand elastic elements (13) of crotch which are arranged longitudinally towards the two outer edges of the central part (8), each longitudinal strip air circulation (17) is fixed on the one hand to the cover sheet (4) in line with the longitudinal side (12) of the absorbent pad (3) and on the other hand to the support sheet (2), included above the elastic elements (13) of the crotch.  10. Disposable absorbent hygiene article according to one of claims 1 to 9 characterized in that, being an article having an hourglass shape with two lateral notches (7) at the central part (8) , each air circulation strip (17) has the same external outline in the form of a half-hourglass as the longitudinal part of the support sheet (2) extending beyond the absorbent pad (3) and it is fixed to their common exterior contours.