GB2041757A

GB2041757A - Sanitary towel

Info

Publication number: GB2041757A
Application number: GB8002827A
Authority: GB
Original assignee: LOreal SA
Current assignee: LOreal SA
Priority date: 1979-02-05
Filing date: 1980-01-28
Publication date: 1980-09-17
Also published as: BE881517A; DE3004144A1; FR2447714B1; FR2447714A1; CH637538A5; GB2041757B

Abstract

A sanitary towel (1) is of elongate parallelpiped shape of absorbent material having along one of its major faces (2) adhesive applied to an area which is symmetrical about the median longitudinal axis of the face (2). The adhesive is applied non-uniformly so that at different cross-sections along the towel (1) the cross-section of the adhesive-coated area (4) is different. The adhesive may be applied in the form of a sinusoidal strip (4) or of an array of regularly spaced patches. This ensures that, without the width of a protective cover strip exceeding the width of the area over which adhesive is applied, the ends of that cover strip are always at least in part on a non-adhesive area and thus lifting of the end of the cover strip (3) to facilitate removal is always readily possible. <IMAGE>

Description

SPECIFICATION Sanitary towel The present invention relates to a sanitary towel. Sanitary pads or towels are known to consist of an absorbent flexible mass of approximately parallelepipedal shape, which is optionally arranged inside either a net or a web which is folded around the absorbent mass and overlapped, in order to form the envelope thereof.

One of the large faces of such a sanitary towel is intended to come into contact with the body of the user and the other large face is arranged on the crutch of the undergarment. In order to hold this kind of sanitary towel in position it is known to provide a strip of adhesive along that large face of the towel which comes into contact with the undergarment. However, in order to avoid undesirable adhesion of the towels during the packaging or transportation thereof and, generally during all the manipulations to which they may be subjected before use, the strip of adhesive is covered with a protective strip. At the time of use, the user removes the protective strip from the adhesive area and applies the towel against the crutch of the briefs so as to hold it in position.

It is also known for this kind of towel to be manufactured continuously from an elongate wad to which the line of glue and then a continuous protective strip are applied, the whole being then cut into lengths in order to produce the individual sanitary towels. Thus, the length of the finished sanitary towel is approximately equal to the length of its protective strip. In a known embodiment, the strip of adhesive is interrupted near one of the ends of the towel. That part of the protective strip which covers this non-adhesive zone constitutes a gripping tab which the user pulls in order to remove the protective strip from the towel at the time of use.When manufacturing the sanitary towel, it is consequently essential to apply a series of separated strips to the elongate wad and to position each adhesive strip relative to the intended cuts of the elongate wad in such a way that on the resultant individual towels the nonadhesive zone which separates two consecutive adhesive strips is indeed located at one end of the protective strip. To do this, it is necessary to synchronise the operation of the adhesive applying roller or rollers with that of the cutting members, and this naturally complicates the operations for the manufacture of the towels.

In order to overcome this disadvantage, French Patent 2,348,691 discloses the provision of a continuous strip of adhesive on the elongate wad from which the towels are produced, and the corrugation of the wad surface at regular intervals in the zones which are to be cut. In the corrugated parts, the elongate wad possesses alternative peaks and troughs, and the continuous protective strip is adhered only to the peaks. Consequently, the protective strip of the finished towels has weaker adhesion at each of its ends, and as a result these ends can easily be detached by the user in order to facilitate removal of the protective strip from the towel.

In one or other of the two known embodiments referred to above, the strip of adhesive, which strip extends apprnximately over the whole length of the towel, tends to render the towel rigid in the longitudinal direction, and this constitutes a disadvantage because such towels are likely to lack flexibility and to be incapable of adapting to the different morphologies of the users.

Furthermore, with the first mentioned embodiment it is necessary to synchronise the operation of the adhesive-applying roller with that of the cutting members, and with the second embodiment an additional corrugating operation is required.

The object of the present invention is to provide a sanitary towel which is intended to be fixed to the crutch of an undergarment by adhesion, and from which the protective strip which covers the adhesive strip can in all cases be easily pulled away by one or both of its ends. Obviously, a technical problem of this kind only arises if the adhesive strip, in the case where it is substantially rectilinear, has approximately the same width as the protective strip. If the rectilinear adhesive strip is covered with a protective strip which is considerably wider than the adhesive-coated area, it will be possible in all cases easily to remove the protective strip by pulling on one of its longitudinal edges.Admittedly, this solves the problem of facilitating detachment of the protective strip, but it increases the cost of the towels because the width of the protective strip must be considerably greater than the width which is strictly necessary in order to cover the adhesive strip.

Likewise, a problem of this kind does not arise in the case where the protective strip is longer than the towel, as described in U. S. Patent No.

3,688,771. Since the length of the adhesive strip is at most equal to that of the sanitary towel, then when the protective strip is longer than the towel, at least one of the ends of the protective strip will project beyond an adhesive zone and will consequently be able to serve as a gripping tab. By increasing the length of the protective strip, and thus also requiring surplus protective strip material (giving rise to increased material costs), this method also solves the problem of facilitating detachment of the protective strip.

Consequently, the problem which the present invention aims to solve only arises if the protective strip has the exact dimensions required to cover the adhesive strip.

Accordingly the present invention provides an elongate sanitary towel consisting of a flexible absorbent mass having a first one of the two large faces of the sanitary towel intended to come into contact with the body of the user, and the second large face making it possible to hold the sanitary towel on the crutch of an undergarment by means of adhesive strip applied to the towel; and a protective strip which covers the said adhesive before use and has a length substantially equal to that of the towel, wherein the adhesive is applied along an area which is symmetrical about an axis extending along the said second face and is applied in a non-uniform manner such that the cross-section of the adhesive-coated regions is different at different stations along the sanitary towel, whereby at least one of the extreme ends of the protective strip is located at least in part over a non-adhesive zone, the width of said area along which the adhesive is applied being similar to the width of the protective strip, and the median axis of the said protective strip being superposed on the said longitudinally extending axis of the towel. In one form of the invention the adhesive strip is a discontinuous rectilinear strip extending across the full width of said area.

Advantageously the spacing between the adhesive patches, their number and their dimensions are chosen, in accordance with the length of the towel, in such a way that at least one of the ends of the protective strip does not cover an adhesive patch. Of course, in this first solution, the protective strip has the exact size required to cover the discontinuous adhesive strip, that is to say the protective strip has approximately the same length as the towel and its width is similar to the width of the area defining the discontinuous adhesive strip.

In a second form of the invention said adhesive is distributed over said area in the form of a sinusoidal strip composed of connected or unconnected adhesive zones, the axis of symmetry of said sinusoidal strip being identical to the said longitudinally extending axis of said area, said sinusoidal strip having a substantially constant amplitude of the adhesive strip of sinusoidal shape similar to the width of the protective strip. With this second solution the adhesive strip of sinusoidal shape can be covered with a removable protective strip of minimum surface area. The protective strip also has approximately the same length as the towel but, in this form, its width is approximately equal to the amplitude of the sinusoidal adhesive strip i.e. the width of the area of the sanitary towel on which the adhesive is applied.The axis of symmetry of the sinusoidal adhesive strip is preferably substantially identical to the longitudinal axis of the protector strip and the amplitude of the sinusoidal adhesive strip is essentially constant.

If the adhesive strip is a discontinuous rectilinear strip, the adhesive zones are preferably uniformly spaced and are preferably substantially identical. In this case, if L denotes the length of the longitudinal median line of the sanitary towel, n denotes the number of adhesive zones and is an integer, p denotes the distance which separates the centres of two consecutive adhesive zones and q denotes the distance which separates the two opposite edges of two consecutive adhesive zones, then the following equation applies: np-q < L < #np.

It is found that, if the parameters L, n, p and q are related by the above mentioned double equation, then regardless of the positioning of the n adhesive zones relative to the two ends of the sanitary towel, at least one of the ends of the protective strip is necessarily located over a nonadhesive zone and can consequently constitute a gripping tab which enables the user to remove the protective strip from the sanitary towel to prepare it for use.

In order to provide a clearer understanding of the subject of the present invention, there now follows a detailed description of two embodiments of sanitary towel in accordance with the present invention. This description is not intended to limit the scope of the invention, and is given with reference to the accompanying drawing, in which:~ Figure 1 is a perspective view of a first embodiment of a sanitary towel according to the invention; the larger of the two faces shown is that face of the towel which comes into contact with the undergarment and is coated with a strip of adhesive of sinusoidal shape but covered with a detachable protective strip; and Figure2 is a perspective view of a second embodiment of a sanitary towel according to the invention, that face of the towel which comes into contact with the undergarment being provided with regularly spaced patches of adhesive, covered with a detachable protective strip.

Figure 1 shows a sanitary towel 1 of elongate shape, having the two ends flattened.

The sanitary towel 1 has been shown in a perspective view based on its large face 2 which, after removal of a protective strip 3, serves to hold the towel on the crutch of a pair of briefs.

The opposite large face, which cannot be seen in the drawing, is intended to come into contact with the body of the user.

In this illustrative embodiment the sanitary towel 1 consists, in a conventional manner, of a flexible absorbent fibrous mass. A web, for example made of paper or of a nonwoven material, is folded around the flexible absorbent mass and overlapped to constitute the external envelope of the sanitary towel 1. In a known manner, an impermeable film (not shown) can be inserted between the absorbent mass and face2 of the external envelope of the sanitary towel 1.

A strip of adhesive 4 is applied over approximately the whole length of the face 2 of the towel. The adhesive employed can be one of the products commonly used to enable the towel 1 to be held on the crutch of an undergarment by simple application against the said crutch. Alternatively, a double-sided adhesive tape can be provided in place of the strip of adhesive 4.

The purpose of the protective strip 3 covering the line of glue 4 is to ensure that, before the sanitary towel is applied to an undergarment, any accidental adhesion of the towel to another towel or to any other surface, such as a packing carton wall, is prevented. The protective strip 3 can be paper or any other suitable material in sheet form, such that that face which comes into contact with the strip 4 of adhesive is easily removable from the adhesive. For example the face in question may have been coated with a release agent such as a layer of silicone or paraffin, in order to make it more easily removable from the adhesive.

One of the essential characteristics of the sanitary towel 1 is derived from the fact that the strip of adhesive 4, which extends essentially from one end of the towel to the other, has a regular sinusoidal shape.

In the particular embodiment of sanitary towel 1 shown in Figure 1 the distance separating two consecutive curved peaks of the sinusoidal strip 4 is approximately equal to the width of the protective strip 3. However, other wave lengths may be used if desired.

Before use, the protective strip 3 is uniformly stuck to the towel 1 by means of the adhesive strip 4. If the protective strip 3 is divided into elementary lengths, each of them, whether it is located in the middle or near the ends of the protective strip 3, covers both an adhesive zone and a non-adhesive zone by virtue of the regular sinusoidal configuration of the adhesive strip 4.

Thus, without the need for taking any particular precaution, it is ensured that despite the use of the sinusoidal strip 4 along the whole length of the sanitary towel 1 , each of the ends of the protective strip 3 will indeed by partially located over a non-adhesive zone and can be used as a gripping tab for removing the protective strip 3 from the sanitary towel 1 at the time of use.

This arrangement is of great value in the manufacture of the sanitary towels 1. A continuous adhesive strip 4 is applied to the long elongate wad from which the individual towels 1 are to be cut and this adhesive strip 4 is covered with one continuous protective strip from which the protective strips 3 will be cut when the wad is cut up to form the towels 1. A single cutting operation can thus not only cut the elongate wad into towel lengths but also close the external envelope at the two ends of each sanitary towel 1, and cut the continuous strip already adhered to the elongate wad, thereby obtaining the various protective strips 3.

As described above, an earlier form of sanitary towel-making process proposed a series of rectilinear and regularly spaced discrete strips of adhesive applied to the elongate wad so as to provide a non-adhesive gripping zone at one of the ends of the protective strip 3. It is necessary to position each of the discrete adhesive strips between two successive intended zones of cut of the elongate wad and, consequently, to make provision for the synchronisation of the movement of the adhesive-applying roller with that of the cutting tools. This involves the possibilities of maladjustment, particularly when the rate of production is high.This problem no longer arises with the form of sanitary towel shown in Figure 1 where the strip 4 of adhesive does not need to be regularly broken; on the contrary it is applied continuously to the elongate wad and, by virtue of the sinusoidal shape of this adhesive strip 4, each end of each protective strip 3 is in all cases partially located over a non-adhesive zone.

Figure2 shows an embodiment in which the adhesive has been applied to the towel in discrete patches rather than in a continuous strip. This embodiment, which is more particularly preferred, exhibits a dual advantage, compared with that of Figure 1, namely (a) that it reduces the amount of adhesive required, because the adhesive is applied along an intermittent area, and (b) that it does not render the sanitary towel rigid in the longitudinal direction by the presence of a continuous strip 4 of adhesive.

Figure2 shows a sanitary towel 5 of essentially parallelepipedal shape having its two ends pressed flat. A web, for example made of paper or of a nonwoven material, is folded around the flexible absorbent mass overlapped to constitute the external envelope of the towel 5. The abovementioned web is closed at its two transverse ends at the moment when the elongate wad, from which the various sanitary towels 5 are produced, is cut. That large face of the towel 5 which is not shown in the drawing is intended to come into contact with the body of the user, and the other large face 6 which is visible in Figure2 is intended to be fixed to the crutch of a pair of briefs.

Patches 7 of adhesive are regularly spaced apart in an array extending along the face 6 and have an approximately equal rectangular surface area. The adhesive patches 7 are located along a mean line which is essentially identical to the longitudinal median line of the face 6. A protective strip 8 is arranged over all the adhesive patches of glue 7 and also extends from one end of the towel 5 to the other. The adhesive patches 7 essentially extend over the whole width of the protective strip 8.

In Figure2, L denotes the overall length of the sanitary towel 5, p denotes the distance separating the centres of two consecutive adhesive patches 7 of the array, and q denotes the distance between the two opposite edges of two consecutive adhesive patches 7.

As is the case for the previously described embodiment the towels 5 are manufactured continuously from an elongate wad which is cut into lengths L. The patches 7 of adhesive are applied to this elongate wad and then a long strip, from which the discrete protective strips 8 which are also of length L are to be produced, is placed in position.

So that at least one of the ends of the protective strip 8 is not located over an adhesive patch 7, even if the operation of the roller for applying the patches of adhesive is not synchronised with that of the tools for cutting the elongate wad, the above-mentioned parameters p, q and L must be related to one another by the following equation (where n represents the number of adhesive patches 7 located on each sanitary towel 5): np-q < L < np.

The lower limit to the length L can correspond to the case where at each of the two ends of the strip 8 there is an adhesive patch 7 with these two patches arranged such that their two opposite edges essentially coincide with the two extreme edges of the protective strip 8. Assuming this to be the case, the protective strip 8 cannot of course be removed by one of its ends, and it is for this reason that the lower value np-q is excluded from the range of values which the length L can take.

On the other hand, L can be equal to its upper limit np. In fact, if L = np, the width of the non adhesive zone 9 located at each end of the protective strip 8 can vary between 0 and q, (depending upon the registration of the adhesive patches 7 and the ends of the strip 8 when cut) and regardless of the position of the n patches 7 on the sanitary towel 5, the width of the larger of the two non-adhesive zones 9 will be bound to be equal to a minimum of q 2 that is to say half the gap separating two consecutive adhesive patches 7.

Within the indicated range, the values of n, p, q and L are chosen so that, if the two end non adhesive zones 9 have approximately the same width (the case where the "larger" of the two end zones 9 has a minimum value for any given set of values of n, pand q), they can provide the user with a sufficient grip to raise and remove the protective strip 8 from the sanitary towel 5. In all other cases possible with this one set of values n, p and q, one of the two end zones 9 will be bound to have a value greater than q 2 In this illustrative embodiment, the length L of the towel 5 and of its protective strip 8 is24 cm.

There are 16 adhesive patches 7, and the distances p and q are equal to 0.16 cm and 0.8 cm, respectively.

Claims

1. An elongate sanitary towel consisting of a flexible absorbent mass having a first one of the two large faces of the sanitary towel intended to come into contact with the body of the user, and the second large face making it possible to hold the sanitary towel on the crutch of an undergarment by means of adhesive strip applied to the towel; and a protective strip which covers the said adhesive before use and has a length substantially equal to that of the towel, wherein the adhesive is applied along an area which is symmetrical about an axis extending along the said second face and is applied in a non-uniform manner such that the cross section of the adhesive-coated regions is different at different stations along the sanitary towel, whereby at least one of the extreme ends of the protective strip is located at least in part over a non-adhesive zone, trea width of said area along which the adhesive is applied being similar to the width of the protective strip, and the median axis of the said protective strip being superposed on the said longitudinally extending axis of the towel.

2. A sanitary towel according to claim 1, wherein said adhesive is distributed over said area in the form of a sinusoidal strip composed of connected or unconnected adhesive zones, the axis of symmetry of said sinusoidal strip being identical to the said longitudinally extending axis of said area, said sinusoidal strip having a substantially constant amplitude of the adhesive strip of sinusoidal shape, similar to the width of the protective strip.

3. A sanitary towel according to Claim 2, wherein the strip sinusoidal adhesive is substantially continuous.

4. A sanitary towel according to Claim 1, where in the adhesive strip is a discontinuous rectilinear strip extending across the full width of said area.

5. A sanitary towel according to Claim 4, wherein discontinuous strip comprises a plurality of substantially identical regularly spaced adhesive patches.

6. A sanitary towel according to Claim 5, wherein if L denotes the length of said longitudinally extending axis of the sanitary towel, n is an integer denoting the number of adhesive patches on the towel and p denotes the distance which separates the centres of two consecutive adhesives patches and q denotes the distance which separates the two opposing edges of two consecutive adhesive patches then: np-q < L < #np.

7. A sanitary towel constructed substantially as hereinbefore described with reference to, and as illustrated in Figure 1 of the accompanying drawing.

8. A sanitary towei constructed substantially as hereinbefore described with reference to, and as illustrated in figure2 of the accompanying drawing.