WO2013077789A1

WO2013077789A1 - Wrap package

Info

Publication number: WO2013077789A1
Application number: PCT/SE2011/051414
Authority: WO
Inventors: Angelica Burvall; Solgun Drevik
Original assignee: SCA Hygiene Products AB
Current assignee: Essity Hygiene and Health AB
Priority date: 2011-11-23
Filing date: 2011-11-23
Publication date: 2013-05-30
Anticipated expiration: 2014-05-23

Abstract

A wrap package for holding individual absorbent articles prior to use, and for disposing of a soiled absorbent article, the package comprising a flexible sheet (1) adapted to be wrapped around the absorbent article, wherein an adhering surface coating (2) is provided on an inward surface (3) of the flexible sheet (1), which inward surface is intended to be facing the absorbent article, said adhering surface coating (2) comprising an adhesive layer (4) applied to said inward surface (3), and an ink pattern is provided at least on top of, or adjacent to, the adhesive layer, which pattern comprises a plurality of three-dimensionally extending projections (5).

Description

Wrap package TECHNICAL FIELD The present invention pertains to a wrap package for holding individual absorbent articles, to an absorbent product wrapped in such a wrap package, and to the use of a wrapping material for packaging of individual absorbent articles. BACKGROUND ART

It is often desired to provide single packed absorbent products, such as panty liners, sanitary napkins and incontinence pads, which can thereby be conveniently and hygienically handled, for example when taken along in a hand bag or the like. For this purpose, wrap packages are commonly used, which are made of a flexible material such as plastic film, such as the one disclosed in US2008/0312629A1 .

However, the disposal of a soiled absorbent product is often a concern for the user, who sometimes uses the wrap package of a new absorbent product to wrap a rolled up used absorbent product. This is an unsatisfactory solution since it may unfold, and the soiled product will also be exposed at the ends of the wrap package material folded around it. SUMMARY OF THE INVENTION

As indicated above, there is a need for an improved way of convenient handling of used absorbent articles before disposal thereof. The present invention aims at solving this by the provision of an improved wrap package for holding individual absorbent articles prior to use, and for disposing of a soiled absorbent article, as defined in claim 1 . The wrap package comprises a flexible sheet adapted to be wrapped around the absorbent article, and includes an adhering surface coating provided on an inward surface of the flexible sheet, which inward surface is intended to be facing the absorbent article. Said adhering surface coating comprises an adhesive layer applied to the inward surface, and an ink pattern is provided on top of, or adjacent tothe adhesive layer, which ink pattern comprises a plurality of three-dimensionally extending projections. The adhering surface coating in combination with the pattern of three-dimensionally extending projections allows the wrap package to function both as a package before use and as a wrapping material for disposing a soiled article. Before use of the absorbent article, the three- dimensionally extending projections act as distances, which prevent or minimise contact between the unused absorbent article and the adhesive layer, so that the package functions as an envelope for the absorbent article. After use, the user can fold the wrap package around the soiled absorbent article and squeeze lightly with the hand. Thereby, as the adhering surface coating is pressed against the soiled absorbent article, the wrap package material will attach to it, and the risk of unfolding is accordingly eliminated, and adhering surface coatings contacting each other lead to a sealed package, thus minimizing odour emission. The ink used for the pattern of three-dimensionally extending projections is preferably one that is expandable upon activation, and the three-dimensionally extending projections accordingly consist of activated expandable ink.

The present invention also relates to an absorbent product packed in a wrap package as indicated above, and to the use of a wrapping material for packaging of individual absorbent articles, which wrapping material, comprises a flexible sheet provided with an adhering surface coating, including an adhesive layer, and a pattern of activated expandable ink provided at least partly on top of the adhesive layer, which pattern comprises a plurality of three-dimensionally extending projections, BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic view of an example of a wrap package of the present invention, laid flat and seen from the inward surface which is to be facing the packed absorbent article;

Figure 2 is a cross-sectional view of the wrap package in Fig. 1 , along the line A-A.

Figure 3 is a perspective view of a package of the invention.

Figure 4 is a schematic view of an alternative suitable pattern which can be used in the present invention.

DETAILED DESCRIPTION

The present invention relates to a wrap package for holding individual absorbent articles prior to use, and for disposing of a soiled absorbent article. The absorbent product may for example be a sanitary napkin, a panty liner, an incontinence pad, a diaper, or any other absorbent product that is suited for single packaging. The package comprises a flexible sheet adapted to be wrapped around the absorbent article, and includes an adhering surface coating provided on an inward surface of the flexible sheet, which inward surface is intended to be facing the absorbent article. Said adhering surface coating comprises an adhesive layer applied to the inward surface, and an ink pattern is provided at least on top of, or adjacent to the adhesive layer, which ink pattern comprises a plurality of three-dimensionally extending projections, so that the wrap package material comprises adhesive areas and protruding non- adhesive areas on its inward surface. The protruding non-adhesive areas act as distances and will prevent the adhesive areas from coming into contact with the absorbent article unless it is pressed against the surface thereof. When pressure is exerted on the wrap package material when wrapped around a soiled article, the protruding areas will be compressed and the adhesive will eventually come into contact with the surface of the article, thus achieving a safe wrapping which does not unfold.

The flexible sheet of the wrap package may be comprised of a polymeric film, preferably a polyethylene film, a laminate, a nonwoven material, or a sheet of tissue. If desired, the flexible sheet can be made of a transparent material, so that the ink pattern can be seen from the outside of the package. The degree of transparency may be chosen depending on the ink pattern to be applied to the inward surface of the package.

The adhesive used for the adhering surface coating may be a pressure sensitive hot melt adhesive. An advantage of using a pressure sensitive hot melt adhesive is that this type of adhesive is open for adhesion to infinity. The adhesive is preferably one that has an adhesive tack which is sufficiently high to allow proper attachment of the wrap package material to a soiled absorbent article, when folded and squeezed around such an article, but which is sufficiently low to prevent damage of an unused absorbent article in case of unintentional pressure being applied to a wrap package containing a new product. The adhesive may also be a reclosable adhesive. The adhesive suitably has an initial adhesive tack 0,5-1 N.

The adhering surface coating may cover substantially the entire inward surface of the package, and the adhesive may then preferably be disposed on the flexible sheet in an even layer. Alternatively, the adhering surface coating may be applied in a pattern on the inward surface of the flexible sheet, covering 10-75 % thereof. The adhesive of the adhering surface coating may be applied by the slot technique, wherein narrow or broad stretches of adhesive may be applied. The adhesive may also be sprayed wherein the width of the adhesive depends on the spray nozzle.

The ink used for the pattern of three-dimensionally extending projections could be any ink that can be applied in a pattern to form extending projections, and is preferably one that is expandable upon activation, and the three-dimensionally extending projections then accordingly consist of activated expandable ink. The activation will be described in more detail below. Such protrusions obtained after expansion of the ink will be relatively soft and compressible, and may thus be excellent as distances for providing a delayed attachment. The ink used for the pattern of three-dimensionally extending projections may alternatively be an ink which forms three- dimensionally extending projections without activation, e.g. having higher viscosity or comprising fillers, so that a printed pattern extends three- dimensionally from the surface onto which it is printed.

The expandable ink can be of a standard formulation known to the skilled man in the art, comprising a polymer, a solvent, binders, thickeners, pigments and a blowing agent or expandable microspheres comprising a propellant. The ink may be applied by printing, e.g. by screen printing, flexoprint, ink jet printing, rotary screen printing or gravure. Application by flexoprint is an advantageous printing method, due to its stability, and insensitivity to dust or particles in the ink. The ink may be applied in selected areas as desired, and in any desired pattern. By printing, any desired pattern of protrusions can easily be obtained. For example, expandable ink may be printed in a pattern of diagonal lines on an adhesive surface coating, so that the adhesive is exposed in diagonal narrow spaces between each printed ink line. It is to be understood that various other printing patterns may also be suitable for use in the present invention. For example, when a transparent or semi-transparent material is used for the flexible sheet, the ink pattern can be designed to indicate front and back directions of the absorbent product, or to indicate which side of the wrap package is adhesive. Further, the pattern can be designed to obscure the view of a soiled product wrapped in the package. Another possibility could be to apply a coloured adhesive and/or a coloured ink, which in various combinations may indicate product type, brands etc. All of the above design alternatives may of course be combined as desired. In cases where the adhesive coating does not cover the entire surface of the wrap package, the ink pattern may also be partially applied outside the adhesive coating.

The amount of ink applied on top of, or adjacent to the adhesive layer will depend on the composition of the ink, on the desired pattern or on the desired height of the protrusions after activation of the ink. The amount of ink needed may vary also depending on the surface absorbency. The skilled person can find out the amount required to achieve the desired surface by routine experiments.

When an expandable ink is applied on the wrap package material, any solvents will evaporate so that the ink dries almost instantaneously. As said above, the expandable ink is activated, in order to obtain a desired effect. During activation, components of the ink swell up due to the action of blowing agent or microspheres, so that the applied ink is transformed into three- dimensional structures, which protrude from the surface of the inward side of the wrap package.

The activation may be carried out by exposing the expandable ink to heat, preferably by means of infra-red radiation, hot air, or microwaves. These heating methods allow flexible and versatile heating, which will provide for effective activation of the expandable ink. Alternatively, the ink may be brought into contact with a heated surface, such as an embossing roll. The activation temperature depends on the amount of ink applied and of the type of ink used, and is typically 80-180 °C, preferably 100-180 °C.

When the adhesive is a hot melt adhesive, which is applied at a temperature on or above the activation temperature of the expandable ink, the ink can advantageously be applied onto the hot melt adhesive while it is still on or above the activation temperature. For example, if the hot melt adhesive is applied at a temperature of 100-180 °C, the expandable ink may be applied while the hot melt adhesive is still at temperature above 80°C. Thereby, the ink is printed and activated in one step, using the heat of the hot melt adhesive for activation. This increases the energy efficiency and speed of the process, since no equipment for supplying heat to the expandable ink is required. If the expandable ink is of a type that can be activated by UV radiation, the activation may instead be performed by means of UV radiation.

When it is desired to obtain a pattern of protruding areas, the expandable ink can be activated so as to obtain expansion only in selected areas, while leaving other areas unexpanded. This can be done by masking areas which are not to be activated, or by directing heat or UV radiation only to areas which are to be activated, e.g. by using a directed beam. Hot embossing can also be used. By activation the ink in selected areas only, creation of different protruding patterns on the wrap package can be accomplished. It is also possible to perform the activation of the expandable ink separately. The means of activation as described above for the in-line activation may of course be used also when activating at a later stage.

After activation, the three-dimensional protrusions are soft and compressible, so that they may act as distances, but can also be compressed, if needed, to allow the adhesive areas to come into contact with the surface to which the absorbent product is to be attached.

The manufacture of wrap packages of the invention may be performed in an apparatus where equipment for carrying out the steps of application of adhesive and ink; activation of the ink (if included in the process) is arranged such that package blanks can be fed through each step in a line production, passing each step of the method. When ready for use, the expandable ink has been activated so as to form three-dimensionally extending protrusions, having characteristics as described above. The three-dimensionally extending protrusions preferably have a height of 0.1 -8 mm, in order to provide sufficient distance to the absorbent product to be held in the package. The height of the protrusions may preferably be 0.5-3 mm. By applying three-dimensionally extending protrusions of a height of 0,5 mm or more, it is ensured that the wrap package does not adhere to the absorbent product, and it is also possible to use a less dense ink pattern. Three-dimensionally extending protrusions of a height of 3 mm allow easier adhesion when pressure is applied to the wrap package material, and makes the product packed in the wrap package more discrete, and thinner, which is advantageous from a storage and transportation point of view.

Advantageously, 5-95 % of the surface area of the adhesive layer is covered by the ink, to ensure that the wrap package does not unnecessarily attach to the unused absorbent article, but to allow the user to conveniently attach the opened wrap package to a soiled absorbent article.

The flexible sheet of the wrap package preferably comprises longitudinal side edge portions, and is folded so as to form an envelope, including a pouch for receiving the absorbent product, and a flap for closing the pouch. The adhering coating can be arranged on the flexible sheet in various ways, to provide improved possibilities of use of the package. For example, it may be desired to apply different adhesiveness to different portions of the package. Two or more portions having different adhesiveness can be arranged on the inward surface of the package.

In an example of a package of the invention, the inward surface is provided with three different adhering coating areas: a first adhering coating area on an edge portion arranged at the distal end of the flap, a second adhering coating area on the longitudinal side edge portions of the flexible sheet, and a third adhering coating area in other portions of the inward surface. In this example the adhesiveness is higher in the edge portion and/or longitudinal side edge portions, than in other portions of the package, which is the central part of the inward surface (third coating area). Thus, by having higher adhesiveness at the longitudinal side edge portions and on the distal end of the flap, than in the centre, the risk of unintentionally attaching the wrap package to the absorbent article in minimised, while at the same time, the user can fold the wrap package around a soiled product and press the longitudinal side edge portions of the flexible sheet together to close the package, or to seal the package by means of the distal end of the flap, which has a higher adhesiveness. The difference in adhesiveness can be obtained by arranging the three- dimensionally extending projections of the central third adhering coating area to have a higher height than the three-dimensionally extending projections of the first and/or second adhering coating area. Thereby, the distance between the top of the three-dimensionally extending projections and the adhesive layer onto which they are applied is increased, and a higher pressure would consequently be needed to attach this area to another surface. At the same time the distance between the top of the three-dimensionally extending projections and the adhesive layer onto which they are applied is not as high in the edge portions, which are not in contact with an unused product packed in the package, and these surfaces can then easily be attached to each other or another surface, with use of less pressure. An alternative way of obtaining the difference in adhesiveness could be to arrange a pattern of three- dimensionally extending projections of the central third adhering coating area, which is denser than the pattern of three-dimensionally extending projections in the first and/or second adhering coating area. A denser pattern covers a larger portion of the adhesive layer, and the distance between each of the three-dimensionally extending projections is smaller. Thereby, the adhesiveness will be higher in areas having a less dense pattern, i.e. the edge portion and/or the longitudinal side edge portions.

It should be understood that different areas of varying adhesiveness can be provided on the wrap package, in any desired manner, and that the effects of using higher and lower three-dimensionally extending projections can be combined with pattern density to obtain the desired adhesiveness.

The present invention also relates to an absorbent product wrapped in a wrap package as described above. Further, the inventions relates to the use of a wrapping material for packaging of individual absorbent articles, where the wrapping material comprises a flexible sheet provided with an adhering surface coating, and which includes an adhesive layer and a pattern of activated expandable ink provided at least partly on top of the adhesive layer, which pattern comprises a plurality of three-dimensionally extending projections. All details given above for the wrap package are applicable also in relation to this wrapping material.

Method to determine initial tack when opening a wrap package

The wrap package must enclose the absorbent article firmly, so that the package will not open by mistake. At the same time the wrap must be easy to remove. A suitable initial tack (force required to open the wrap) can be evaluated with a tensile tester. Tensile testers are available from e.g. Lloyd Instruments Ltd or the Instron Corporation. The adhesive must set before testing. At least a week must pass between production date and test occasion. The wrap's attachment lines (such as 1 1 or 12 in Fig. 3 below, i.e. the stripes that should be teared when removing the wrap) are cut free from a closed wrap package. The clamps of the tensile tester are positioned 25 mm apart (gauge length). The two layers in the stripe's end portion are separated slightly, and are then positioned into the respective clamps. The layers are delaminated at a speed of 500 mm/min. The maximum force encountered in the delamination should suitably be 0,5-1 N. The invention will now be described in relation to the drawings, where Fig. 1 shows an example of a wrap package of the present invention, laid flat and seen from the inward surface, which is to be facing the packed absorbent article, and Fig. 2 is a cross-sectional view along the line A-A. The package is shown in perspective in Fig. 3.

The wrap package comprises a flexible sheet 1 adapted to be wrapped around the absorbent article. An adhering surface coating 2 is provided on an inward surface 3 of the flexible sheet 1 , which inward surface is intended to be facing the absorbent article, which is packed in the wrap package. The adhering surface coating 2 comprises an adhesive layer 4 applied to the inward surface 3, and an ink pattern comprising a plurality of three- dimensionally extending projections 5 is provided on top of the adhesive layer 4.

As shown in Fig. 3, the flexible sheet of the package is folded so as to form an envelope 6, including a pouch 7 for receiving the absorbent article, and a flap 8 for closing the pouch 7. The inward surface 3 of the package comprises three distinct adhering coating areas. Fig. 1 shows how the first adhering coating area 10 is arranged on an edge portion 1 1 at the distal end of the flap 8, and a second adhering coating area 12 is arranged on the longitudinal side edge portions 13 of the flexible sheet 1 , and a third adhering coating area 14 covers other portions of the inward surface 3. Each of these adhering coating areas has a selected adhesiveness, which can be obtained by choosing the height of the three-dimensionally extending projections or the pattern density thereof. Thus, for example the three-dimensionally extending projections 5"' of the third adhering coating area 14 have a higher height than the three-dimensionally extending projections 5', 5" of said first and/or second adhering coating area 10, 12. The cross-sectional view of Fig. 2 illustrates how the three-dimensionally extending projections are higher in the central portion of the flexible sheet 1 . Figure 4 shows an example of a suitable pattern which can be used in the present invention. Here, the outline of an absorbent product is indicated in an area having a denser pattern of three-dimensionally extending projections, than the pattern of three-dimensionally extending projections in the surrounding area.

Claims

A wrap package for holding individual absorbent articles prior to use, and for disposing of a soiled absorbent article, the package comprising a flexible sheet (1 ) adapted to be wrapped around the absorbent article, characterised in that an adhering surface coating (2) is provided on an inward surface (3) of the flexible sheet (1 ), which inward surface is intended to be facing the absorbent article, said adhering surface coating (2) comprising an adhesive layer (4) applied to said inward surface (3), and an ink pattern is provided at least on top of, or adjacent to, the adhesive layer, which pattern comprises a plurality of three-dimensionally extending projections (5).

The package of claim 1 , wherein the ink is expandable upon activation and the three-dimensionally extending projections accordingly consist of activated expandable ink.

The package of claim 1 , wherein the adhering surface coating (2) substantially covers the entire inward surface (3).

The package of claim 1 , wherein the adhering surface coating (2) is applied in a pattern on the inward surface (3), covering 10-75 % thereof.

The package of any one of claims 1 -4, wherein 5-95 % of the surface area of the adhesive layer (4) is covered by the ink.

The package of any one of claims 1 -5, wherein the three- dimensionally extending projections (5) have a height of 0.1 -8 mm, preferably 0.1 -3 mm.

The package of any one of claims 1 -6, wherein the flexible sheet comprises longitudinal side edge portions (13), and is folded so as to form an envelope (6), including a pouch (7) for receiving the absorbent article, and a flap (8) for closing said pouch (7), and wherein the inward surface (3) is provided with

a first adhering coating area (10) on an edge portion (1 1 ) arranged at the distal end of the flap (8), and a second adhering coating area (12) on the longitudinal side edge portions (13) of the flexible sheet (1 ), and a third adhering coating area (14) in other portions of the inward surface (3), wherein

the three-dimensionally extending projections (5"') of said third adhering coating area (14) have a higher height than the three- dimensionally extending projections (5', 5") of said first and/or second adhering coating area (10, 12),

thereby providing a higher adhesiveness in said edge portion (1 1 ) and/or longitudinal side edge portions (13).

8. The package of any one of claims 1 -6, wherein the flexible sheet comprises longitudinal side edge portions (13), and is folded so as to form an envelope (6), including a pouch (7) for receiving the absorbent article, and a flap (8) for closing said pouch (7), and wherein the inward surface (3) is provided with

that the pattern of three-dimensionally extending projections (5"') of the third adhering coating area (14) is denser than the pattern of three- dimensionally extending projections (5', 5") in said first and/or second adhering coating area (10, 12),

9. The package of any one of claims 1 -8, wherein the flexible sheet (1 ) is comprised of a polymeric film, preferably a polyethylene film, a laminate, a nonwoven material, or a sheet of tissue.

10. The package of any one of claims 1 -9, wherein the flexible sheet (1 ) is transparent, so that the pattern of activated expandable ink can be seen from the outside of the package.

1 1 . An absorbent article wrapped in a wrap package according to any one of claims 1 -10.

12. The use of a wrapping material, comprising a flexible sheet (1 ) provided with an adhering surface coating (2), which includes an adhesive layer (4) and a pattern of activated expandable ink provided at least partly on top of the adhesive layer (4), which pattern comprises a plurality of three-dimensionally extending projections (5), for packaging of individual absorbent articles.