MXPA97002539A - Absorbent sanitary article with expandib fins - Google Patents

Abstract

An absorbent article, such as a sanitary napkin, comprises an absorbent region (10) capable of absorbing bodily fluids and a pair of fins (20), located one on each of the opposite edges of the absorbent region (10). Each fin (20) is not planar and has a first edge, where the absorbent region (10) joins, which defines a non-rectilinear axis of rotation for the fin to rotate with respect to the absorbent region (10), and a second edge, away from said absorbent region (10), where the perimeter length is greater than for an equivalent flat fin (20). This can be achieved by stretching the material of each of the fins (20) in such a way that it assumes a wavy shape.

Description

* «T ABSORBENT SANITARY ARTICLES CONALETAS EXPAND FIELD OF THE INVENTION 5 The present invention relates to sanitary absorbent articles.

BACKGROUND OF THE INVENTION -J-0 Absorbent articles such as sanitary napkins, panty liners, and incontinence pads are devices that are typically used in the crotch region of an undergarment. These devices are designed to absorb and retain liquids or other discharges of the human body, and to prevent staining of clothing and body. Sanitary napkins are a type of absorbent items used by women in a pair of panties, which are usually placed between the legs of the user, adjacent to the perineal area of the body. The sanitary napkins both with and without lateral fins (or wings), are described in literature and are available in the market. Some particularly preferred sanitary napkins that do not require fins are described in the US Pat.

No. U.S. Patent No. 4950264 and U.S. Patent No. 5009653. Generally, when finned sanitary napkins are provided, the flaps extend laterally from a central absorbent means and are intended to be folded around the edges of the panty liners. user in the crotch region. In this way, the fins are arranged between the edges of the wearer's panties in the crotch region and the thighs of the wearer. Commonly, the fins are provided with a fixing means for either fixing the fins to the lower surface or to the opposite fin. The fins are effective particularly to prevent the exudates from staining the edges of the wearer's panties. Sanitary napkins having fins of various types are described in U.S. Patent No. 4687478, U.S. Pat. 4608047, Patent of the United States NO. 4589876, United States Patent NO. 4285343, Patent of the United States NO. 3397697, and U.S. Patent No. 2787271. Although sanitary napkins having fins are commonly seen as providing better protection against staining as compared to sanitary napkins without fins, some women find it inconvenient to apply towels sanitary companies that have fins for several reasons. For example, some women find it difficult to attach the fins to the underside of the crotch of their panties. This may be due to factors such as the tendency of the adhesive fasteners to stick on the fins or other parts of the sanitary napkin. As a result, some women still prefer a sanitary pad without fins, and some women who generally prefer a sanitary pad with fins, occasionally (such as 5 during periods of light flow) prefer a sanitary pad without fins. Therefore, there is a need for a sanitary napkin that provides an alternation for sanitary napkins having conventional side flaps while still providing protection of the side flaps. In addition, both sanitary towels with and without fins are subject to the problem that the wearer's garment moves with the user's movement during use.Most sanitary napkins, however, do not provide the mechanism for adjusting to these movements, this puts tension on the towel sanitary and fins. These tensions can cause the sanitary napkin to deviate from its desired position in the wearer's undergarment. The failure to provide the sanitary napkin with a mechanism of adjustment to the differences between the movement of the user's undergarments and the body of the wearer, may also cause the sanitary napkin to be less comfortable than if it were to stretch and conform to the wearer's movements, and to the wearer's undergarments. Several variations of sanitary napkins that have conventional fins that try to solve something, but not all of these problems, are described in the patent literature.

For example, U.S. Patent No. 4911701 (Mavinkurve) describes a sanitary napkin that has elastic threads to provide a more convex shape to the position it faces towards the body of the central absorbent and to enable the free placement of the adhesive of the fins of a winged towel modality in a pair of panties. The sanitary napkins described in the Mavinkurve patent, however, still appear to require the user to manipulate the fins (lifting the fins up first and then l, placing the fins on their panties and lifting the fins back down), since the fins appear to be predisposed to be in a bent down condition. Also the Mavinkurve patent requires that the individual elastic threads be fixed in the contracted condition to the central absorbent portion of the towel and / or its wings or fins. The sanitary napkins described in the Mavinkurve patent may, therefore, be difficult and expensive to manufacture. The Mavinkurve patent also does not describe any mechanism that considers differences in movement and extension capacity of the central absorbent of the sanitary napkin and the wearer's panties. U.S. Patent No. 4940462 (Salerno) discloses a sanitary towel with longitudinally expandable fins. The fins are designed to fold over the outside of the wearer's panties and then expand to conform to the contour of the panties. The Salerno patent, however, appears to require conventional adhesive fasteners to retain the flaps in place on the undersurface of the wearer's panties. In addition, in order for the fins of Salerno to extend, a sufficient amount to wrap around the elastic of the panty, the fins must have a broad transverse dimension, elastically. The extra material of the fin can extend too far outward, beyond the elastic of the panty to create a wet and dirty edge that hangs out of the wearer's panties. It is an object of the present invention to provide an absorbent article, such as a sanitary napkin, that overcomes, or at least mitigates some or all of the problems described above.

BRIEF DESCRIPTION OF THE INVENTION According to the present invention, an absorbent sanitary article is provided herein which comprises an absorbent region capable of absorbing body fluids and having a pair of fins located one on each of the two opposite edges of the absorbent region, each fin being not flat and having a first edge, closer to the absorbent region, whose edge defines a non-rectilinear axis of rotation for the fin to pivot or rotate with respect to the absorbent region, and a second edge, away from said absorbent region, where the perimeter length is greater than for a flat equivalent fin. It should be understood that the first edge of each flap may be in, or substantially parallel to, a corresponding non-rectilinear edge of the absorbent region, as is the case of the embodiment described below with reference to the drawings. However, alternately said first edge may be theoretical instead of real in the articles as manufactured. The side edges of the absorbent region may, for example, be straight, with the first of said edges being within an area that lies outside the boundaries of the absorbent material. In any event, however, said first edges are those around which the fins rotate in use, with respect to the rest of the article that includes said absorbent region.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be further described with reference to the accompanying drawings, in which: Figure 1 is a plan view, seen from the side of the upper sheet, of a blank form from which a embodiment of the invention in the form of a sanitary napkin, showing the extent to which the different regions of the article are to be stretched.; Figure 2 is a plan view of a sanitary napkin made from the blank form of Figure 1; Figure 3 is a side view of the sanitary napkin of Figure 2; Figures 4, 5 and 10 show three alternative patterns in which the panty fastening adhesive can be applied to an article according to the present invention, again in the form of a sanitary napkin; and Figures 6 to 9 are cross-sectional, diagrammatic views, through four alternate embodiments of the invention, as applied to sanitary napkins.

DETAILED DESCRIPTION OF THE INVENTION Referring first to Figure 1, it shows the blank form from which the sanitary napkin can be foraccording to the present invention. It will be seen that it comprises an absorbent core 10, which has longitudinal, parallel, straight sides and rounded ends, and a secondary upper sheet 12 which is hourglass-shaped and which covers the core 10. The ends of the upper sheet secondary coincide with the ends of the core 10, however, there are additional corner portions 12a below which the core 10 is not present. A primary upper sheet 14 of generally elliptical shape is placed on the secondary upper sheet, and a posterior sheet in the same form it is located below the core 10. Both the primary upper sheet 14 and the secondary upper sheet 12 are permeable to liquid, although the upper sheet 14 may only be permeable in a central region thereof, and may be impermeable in a peripheral region of it. The back sheet must be impermeable to liquid. The backsheet and the topsheet are sealed together, preferably by a heat seal, albeit alternately, by adhesive, along a strip 18 having the same shape as the periphery of the secondary top sheet 12, and it is separated outward from it. The secondary upper sheet 12 and the core 10 are, therefore, encapsulated between the upper sheet 14 and the rear sheet 16. A pair of side regions 20 are for forming the lateral fins, they are constituted by portions of the upper sheet / leaf assembly posterior that falls out of the nucleus and the upper secondary leaf. In each of these regions 20, the backsheet and the topsheet are sealed together by an adhesive that extends over mutually facing surfaces thereof. However, it would be possible alternately for the upper sheet and the back sheet to be secured to each other in the regions 20 by other means, for example by means of additional heat seals on the outer edges laterally thereof. In the manufacture of the towel, each of these regions is subjected to stretching both in a longitudinal direction (i.e., parallel to the longest axis of the sanitary napkin), and in a transverse direction (i.e. in a direction in angles) straight to the anterior longitudinal direction). In a conventional process for producing sanitary napkins, which can be modified to produce towels according to the present invention, the wefts of the raw material to form the upper sheets and backsheets travel through the manufacturing process in a direction parallel to the longitudinal axis of the articles, and this direction is therefore referred to in a conventional manner as the machine direction (MD). The direction at right angles to this is therefore referred to in a conventional manner as the transverse direction (C.D.). In the description that follows, reference will be made to the address of the machine (MD) and cross direction (CD), but it should be understood that what is significant for the purposes of the present are the directions with reference to the article instead of with reference to the machine by which the article can be for and that MD and C.D., are therefore to be understood in the present context as a primary reference to a direction parallel to the longitudinal axis of the towel, and to a direction in which it is transverse to it, respectively. As already indicated, each of the regions 20 is subjected to both CD stretch and MD stretch For easy illustration, the extension of the CD stretch is shown in only one of the regions and the extension of the stretch. in MD is shown only in relation to the other of the regions, it should be emphasized, however, which, in reality, both regions are subjected to both forms of stretching. Referring first to the upper part of the two regions 20 illustrated in Figure 1, this is subjected to a stretching amount ranging from 10% in the longitudinal intermediate to 50% at the longitudinal ends. The degree of stretching is shown as being in bands of 10%, 15%, 20% 35% and 50%. These bands are shown for illustrative purposes only, and in fact, the amount of stretching may vary at least approximately continuously over the length of the fin. For a first approximation, it can be assumed that the values of 10%, 15%, 20% and 35%, are achieved around half of the bands that are marked with these values, and the value of 50% is achieved in the extreme extremities. It should be understood that although the stretch percentage varies substantially between half the fins and their ends, the actual amount of stretching will not vary to a corresponding point, because the amount of material available to be stretched is much larger in the center that in its extremes. The scale of "CD stretch" may in fact be less than or greater than, as illustrated in Figure 1. For example, this may vary from less than 10% in half (still going down to zero at this point). up to as much as about 70% at the ends.The lower region 20 in Figure 1 has a uniform amount of stretching in MD (10%) marked on it.This is only an approximation, and can be taken as the average value of the Stretching is considered from the fin region laterally inward to the fin region laterally outward The amount, laterally inward, of the stretch in MD can be reduced almost or completely to zero The amount, laterally outward of the stretch in MD it reaches a value that exceeds 10%, and can actually reach a value close to 20%, or even up to approximately 40% .The result of the combined stretch in CD and MD causes ripples or waves 22 which are formed in the regions 20, in this way, creating fins 20a. This can be seen in Figures 2 and 3. The undulations 22 have their higher amplitudes at their laterally external ends, falling to zero, or almost to zero, at their inner ends. The periodicity of the undulations 22 is constant approximately from one end to the other. The effect of the corrugations 22 is that the length of the laterally outer edge of each of the fins 20a, as measured throughout '* of a trajectory that follows the rise and fall of the undulations, increases compared to what it would have been if the ripples would not have formed. Preferably, the resulting increase in the perimeter length of each fin is from 10 to 70%, more preferably from 15 to 50%, and even more preferably from 20 to 30%. Mostly preferable, this increase is approximately 25%. The materials from which the top sheet and the back sheet are formed must, therefore, be such that they are capable of being stretched. In addition, the materials are thus chosen that, at least in their stretched condition, are not elastic, or at least not elastic to no significant extension. In addition, the materials are shrunk so that, although they can be stretched during the course of manufacture of the article, they do not easily stretch later. By this it is understood that, they are not stretched to any significant extent during normal use, although This does not mean that a user can not perform some stretching of the materials if, contrary to what is intended, the user would try to do so. The regions 20 of the blank form shown in Figure 1 can be stretched by any appropriate method. Without However, a preferred method is as described in our co-pending Italian patent application filed on the same date as the present application entitled (). This discloses a method for deforming a sheet-like region of an absorbent sanitary article, wherein said region is positioned between a molding member having at least one opening or a recess therein, and preferably a plurality of such openings or openings. recesses, and a deformation member, forcing the deformation member to said region toward said opening or recess. Preferably, the deformation member comprises an elastic membrane, and the movement of the elastic membrane is effected by a fluid exerting a pressure thereon. A portion of the article around said region is secured during movement of the elastic member. The backsheet 16 has applied to this the fastening adhesives of the panty. The back sheet, with its adhesive, is usually covered by a protective release layer, which is removed by the user immediately before using the article. Figures 4 and 10, each show a pattern of adhesive comprising two parallel central strips 30 and two side strips outward 32, the latter extending towards the outer edges of the article. In Figure 4, the strips 32 cover, inter alia, the fins 20a and, in Figure 10 they cover only the fins. Figure 5 shows an alternate adhesive pattern, in which the central zone 34 is free of adhesive, and there are two relatively broad strips of adhesive 36 that stop away from the side edges of the article. In this case, there is adhesive on the side side - internal of each fin, but not on its external lateral part. The drawings show, by way of example only, some measurements in millimeters for the dimensions of the adhesive strips. The article itself has, in this case, a total length of 227mm and a total width of 119mm. The fins of the article according to the present invention, are thus designed so that, when the user has secured the article of the crotch region of a pair of panties, and has then pulled those panties over it, the fins will automatically wrap. by themselves in the desired position that covers the outside of the crotch region, without the user needing to take any additional action to achieve this. The reason why this is possible can be understood from a consideration of Figure 2, where the additional lines 40 have been drawn therein to indicate the edges of the crotch region of the panties. It must be understood that, the precise lines shown are not universally the same, and that there are, in particular, differences from one part of the world to another as is considered the form of the panties that is normally preferred. However, the lines that are shown as regularly typical, and the principle of which is being illustrated is of general applicability. However, it could be desirable, in order to provide panties with crotch regions widely different from those shown, for , "* make a difference corresponding to the shape of the sanitary napkin, as can be seen in Figure 2, the lines 40 are each at least roughly the shape of a segment of an ellipse. user directs the panties with this sanitary napkin on it, in an upward direction, the portions of the flaps 20a outwardly from the lines 40 are located against the wearer's thighs, and tend to bend downwardly around the thighs of the wearer. the lines 40. Once these portions of fins are oriented at 90 ° with respect to the general plane of the rest of the article they are unstable in their positions and tend to continue their rotation, bending it under the crotch region of the panties. of the pantyhose then causes the fins to adhere to the lower surface of the crotch region, if the extension to which the fins bend is not sufficient to produce this adhesion, or if adhesion occurs to an insufficient extent, the user can perform it manually. The presence of the corrugations 22 in the fins, and the consequent increase in peripheral length laterally outward thereof are critical for the foregoing bending action to occur. It will be readily understood that although it is possible to bend a flat sheet around a straight axis without producing it, it is not possible if the axis around which the folding takes place is curled, unless the sheet is stretchable (the material of the sheets). fins in the article of the present invention is not). What makes folding possible in the present case, without any puckering, is that the fins are not flat. The non-flat nature of the fins not only allows bending to take place around the line 40, but also means that after the fins have been folded, and are placed against the inner surface of the crotch region of the panties, the Increased length of the outer edge of the fins enables those fins that lie without substantial puckering against the undersurface of the crotch region. Figures 6 to 9 show a number of possible constructions for a sanitary napkin made according to the present invention. It is emphasized that the drawings are highly diagrammatic. In this way, for example, the waves that can be seen at the outer edges of some of the components, although represented by the undulations 22, are shown for ease of illustration running at right angles to the actual orientation of the corrugations 22. A number of the components in Figures 6 to 9 are common to those that have been described above and the same reference numbers are used. Additionally, however, each of Figures 6 to 9 uses the reference numerals 52 to denote the protective release layer, and the reference number 54 denotes the adhesive used to secure the backsheet and the topsheet together. The embodiment of Figure 7 also comprises two strips of soft nonwoven material 56 which are secured by the adhesive 58 to the surface of the topsheet 14, in the regions where the topsheet covers the longitudinal edges of the core 10 and the topsheet Secondary 12. This is done in order to reduce the sharpness of this union, and increase comfort to the user. The same is true in the case of the embodiment of Figure 8. The embodiments of Figures 6 and 7 use the adhesive pattern shown in Figure 4, whereby Figure 8 uses the adhesive pattern shown in Figure 5. The embodiment shown in Figure 9 is substantially the same as that shown in Figure 8, except that the topsheet 14 does not extend far outwardly laterally. The sanitary napkin described above can be made of various materials, but, by way of example, the following table sets forth the construction of an embodiment of the present invention. \ 3I1 = hydrogel superabsorbent material

Claims (1)

1. CLAIMS 1. An absorbent sanitary article comprising an absorbent region capable of absorbing bodily fluids and having a pair of fins located one on each of the two opposite edges of the absorbent region, each fin being non-planar and having a first edge , closer to the absorbent region, whose edge defines a non-rectilinear axis of rotation for the fin to rotate or rotate with respect to the absorbent region, and a second edge, spaced from said asorbent region, wherein the perimeter length is greater than for an equivalent flat fin. 2. - An absorbent sanitary article in accordance with claim 1, further characterized by which the perimeter length of each fin exceeds that of an equivalent flat fin, is 10-70%. 3. - An absorbent sanitary article, according to claim 2, further characterized in that said amount is from 15 to 50%. 4. - A sanitary absorbent article according to claim 3, further characterized in that said amount is from 20 to 30%. 5. - An absorbent sanitary article according to claim 4, further characterized in that said amount is approximately 25%. 6. - An absorbent sanitary article according to any of the preceding claims, further characterized in that the overall shape thereof is at least approximately that of an ellipse. 7. An absorbent sanitary article according to any of the preceding claims, further characterized in that the absorbent region has lateral edges that are coincident with, or substantially parallel to, said first edges of the fins. 8. - An absorbent sanitary article according to claim 7, further characterized in that the absorbent region has an hourglass shape. 9. An absorbent sanitary article according to any of the preceding claims, further characterized the non-planar shape of the fins results from the application of a stretching force to these. 10. An absorbent sanitary article according to claim 9, further characterized in that each flap as seen in plan view, has its maximum width at an intermediate point at its ends, and generally tapers from this point toward those ends. 11. An absorbent article according to claim 9, further characterized in that the stretching force comprises at least one component in a direction parallel to the width of the fins, whose component results in an amount of stretching that increases, considered as a percentage of the unstretched width of the fins, from the region of maximum width to said ends. 12. - An absorbent sanitary article according to claim 11, further characterized in that said component parallel to the width of the fins is increased to a value of no more than about 70% at said ends. 13. - An absorbent sanitary article according to claim 12, further characterized in that said component parallel to the width of the fins is increased to a value of no more than about 50% at said ends. 14. - A sanitary absorbent article according to claim 12 or 13, further characterized in that said component parallel to the width of the fins has a value of 0 substantially in the region of maximum width. 15. - An absorbent sanitary article according to claim 12 or 13, further characterized in that said component parallel to the height of the fins has a "-" 'value of at least about 10% in the region of maximum width. 16. An absorbent sanitary article according to any of claims 9 to 15, further characterized in that the stretching force comprises at least one component in a direction parallel to the length of the fins., whose component results in an increasing amount of stretching, considered as a percentage of the unstretched length of the fins, from said first edge towards said second edge. 17. An absorbent sanitary article according to claim 16, further characterized in that said component parallel to the length of the fins has a value of no more than about 40% in the second edge. 18. An absorbent sanitary article according to claim 17, further characterized in that said component parallel to the length of the fins has a value of no more than about 20% in the second edge. 1 . - An absorbent sanitary article according to claim 18, further characterized in that said component parallel to the length of the fins has a value of 0 substantially at the first edge. 20. An absorbent sanitary article according to any of claims 16 to 19, further characterized in that the average value of said component parallel to the length of the fins is approximately 10%. 21. An absorbent sanitary article according to any of the preceding claims, further characterized by having a wavy shape and having a plurality of corrugations, each of which has its ridge running generally parallel to the width of the fin. 22. An absorbent sanitary article according to claim 21, further characterized in that the amplitude of each corrugation increases as it is considered in a direction from said first edge towards said second edge. 23. An absorbent sanitary article according to claim 21 or 22, further characterized in that the corrugations are at least, approximately, equidistant from each other. 24. An absorbent sanitary article according to any of the preceding claims, comprising, from a surface of the article to an opposite surface, a liquid-impermeable backsheet, an absorbent core and an upper sheet impervious to liquid. 25. An absorbent sanitary article according to claim 24, characterized in that it further comprises a secondary upper sheet permeable to the liquid located between the core and the first of said upper sheet. 26. An absorbent sanitary article according to claim 25, further characterized in that at least the secondary upper sheet has an hourglass shape. 27. An absorbent sanitary article according to any of claims 24 to 26, further characterized in that a respective strip of soft material is secured on the first upper sheet mentioned in each of the regions wherein the first mentioned upper sheet lies on a longitudinal edge of the core and, if present, the secondary upper sheet. 28. An absorbent sanitary article according to claim 27, further characterized in that said soft material is a non-woven material. 29. An absorbent sanitary article according to any of the preceding claims, further characterized in that the material of the fins is a ~ f your non-elastic plastic material or combination of plastic materials, not easily stretchable in use. 30. An absorbent sanitary article according to any of the preceding claims, further characterized in that a surface thereof has 15 adhesive to secure the item to a user's garment. 31. An absorbent sanitary article according to claim 30, further characterized in that said adhesive is applied in a pattern comprising two strips 20 parallel ones separated from a longitudinal center line extending parallel to the length of the fins, and two strips laterally outward, each separated outwardly from a respective strip of the first mentioned strips. 32. An absorbent sanitary article according to claim 31, further characterized in that each of the strips laterally outwardly extend at least substantially to a respective lateral edge of the article. 33.- A sanitary article absorbene according to claim 30, further characterized in that said adhesive is applied in a pattern comprising two parallel strips separated from a longitudinal central line extending parallel to the length of the fins, each of the strips covering at least part of a respective strip of the fins. 34. An absorbent sanitary article according to claim 33, further characterized in that none of the strips extends towards a respective lateral edge of the article.