Method, apparatus and article related to a hook-and-loop flexible fastening system

The subject of the invention is a method for producing an absorbent article with a secured fastening system and an apparatus for producing an absorbent article with a secured fastening system.

In cheap or disposable items, such as diapers having sections of tape covered with self-adhesive glue, various fastening systems have been used so far, for example snaps and hook-and-loop fasteners. Due to the exposure of the adhesive tape to contamination, for example with talcum powder or baby oil, diapers equipped with hook and loop fastening systems are now gaining an increasing market share.

From EP-A-0 491 347, EP-A-0 324 578 and EP-A-0 276 970, various types of hook and loop fastening systems are known. In these solutions, the fastening tabs are attached to the first waist part of the diaper, the fastening tab is provided with a region of hook material and an application zone located in the second waist part, in the application zone there are numerous loops intended to be connected to the hooks. The fastener tab is usually a flexible, rectangular longitudinal strip of polymeric material, the first end of which is attached to the diaper. The region of hook material is located in the distal portion of the tip tab protruding past the edge of the diaper, which allows the first waist portion of the diaper to be positioned around the wearer's body and secured in the second waist portion and thus holding the diaper in place on the user's body.

The disposable diaper generally consists of a liquid-impermeable back sheet, a liquid-permeable cover sheet, and an absorbent core sandwiched between the cover sheet and the bottom sheet. To improve fit and comfort, disposable diapers may also have elastic leg cuffs and elastic waist sections. The production process of disposable diapers is highly automated, where component materials are fed into the production line, and wrapped ready-to-ship products intended for the user leave the line. As in all production lines, it is necessary to avoid defective batches and breaks in work.

In order to prevent the machine from being caught by the hook-and-loop fastening tabs of the fastening system when moving the diapers along the production line, it is important that these tabs are kept in a storage position in which the distal portion of the tip of the tab is folded over the first portion of the tip where it contacts the diaper top sheet. This storage position should be maintained throughout the entire diaper passage through the production line, as a result of which the diaper will be stored and packaged with the flaps in the storage position. Thus, after opening the package, the user has carefully folded diapers without visible flaps.

Although many diapers currently sold have outer layers made of non-woven material where loops are formed to some extent, with which the fastener tab hooks can attach after folding the tab to the storage position, the strength of such a combination has sometimes proved insufficient to guarantee that the tabs remain in the storage position during passage diapers along the production line. As a result of the elasticity of the flaps, they can be opened and the devices jammed in the line, leading to production stoppages or production of deficiencies due to the presence of defective products.

In the solution described in EP-A-0 324 578 this problem is partly solved by applying a patch with a layer of self-adhesive adhesive in its central part, as a result of which the central part of the patch may adhere to the part of the patch that is permanently attached to the diaper when the patch is in the storage position.

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Another possible solution to this problem could be the use of a top sheet of a diaper with a patch of loop material adjacent to the first end portion of the tab, for example the remote end portion of the tab on which the hooks were attached and which could attach to the loop material in the storage position. This solution could, however, increase the cost of the product due to the need for additional loop material.

The object of the present invention is therefore to provide a method for producing an article with a secured fastening system and an apparatus for producing an absorbent article with a secured fastening system.

The method of producing an absorbent article with a secured fastening system in which the first fastener member is permanently attached to the article and protruding hook members arranged on the second fastener member according to the invention are characterized by that the hook members of the second part and the surface of the article are subjected to relative displacement in a direction substantially parallel to this surface of the article increasing the holding force between the second part and the surface.

Preferably, the second part of the first member and the surface of the article are led through the notch, thereby creating a mutual displacement.

Preferably the second part of the fastener member and the surface of the article are passed through a pair of cooperating rollers.

Preferably, the second part of the fastener member and the article surface are guided along a guide groove before and after the pair of rollers.

Preferably the second part of the fastener member and the surface of the article are passed through an upwardly open channel in the rolling block.

Preferably a closed belt is led through the channel and the second part of the fastener member and the surface of the article are passed between the belt and the walls of the channel.

Preferably, the distal end portion of the fastener member is folded over to the first portion of the fastener member and the hook members are in contact with the surface of the article, followed by mutual displacement of the distal end portion and the surface of the article in a direction substantially parallel to the surface of the article.

An apparatus for producing an absorbent article with a secured fastening system comprising a second station comprising application means for applying fastening members on an article of the invention is characterized in that the device also includes a third station comprising displacement means for producing relative movement between the hook members located on the fastener members and the surface of the article .

Preferably, the third station comprises at least one notch that produces mutual displacement.

Preferably, the third station comprises a pair of cooperating rollers, this pair consists of a notched roller having a circumferential projecting notch and rollers in a notch having a circumferential notch.

Preferably, the notch or groove is covered with an elastic material such as rubber.

Preferably, the third station further comprises a guide groove in front of and behind the notch.

Preferably, the station comprises a rolling block having an upwardly open channel through which an endless tape passes, the second part of the fastener and the surface of the article passing between the tape and the walls of the channel.

Because the method provides a better connection between the surface of the article and the hook members, existing diaper elements can be used without the need for additional means, such as glue or additional loop material.

The subject of the invention in an embodiment is shown in the drawing, in which Fig. 1 is a schematic perspective view of a diaper provided with a hook-and-loop fastening system, in the first embodiment made by the method of the invention, Fig. 2 - a section taken along line II- II according to Fig. 1, schematically, Fig. 3 - a section corresponding to Fig. 2, but with the fastener member in the storage position, Fig. 4 - is a schematic perspective view of a diaper provided with a hook and loop fastening system, in a second embodiment using the method according to the invention, Fig. 5 - a cross-sectional view along the line VV according to Fig. 4, schematically, Fig. 6 - a cross-section corresponding to Fig. 5, but with the fastener member in the storage position, Fig. 7 - block diagram of a production line comprising the method according to the invention, Fig. 8A - device for carrying out the method according to the invention, schematically in front view, Fig. 8B, device in accordance with Fig. 8A, schematically in side view, Fig. 9 - diaper passage according to Fig. 4 through the device in Figs. 8A and 8B as a view corresponding to Fig. 8A, enlarged, Fig. 10A - the second part of the fastener member before the method according to the present invention is used schematically, Fig. 10B - the second part of the fastener after the method of the present invention has been schematically used, Fig. 11 - fastener in the storage position, schematically in cross-section, Figures 12A to 12J - various shapes of rollers that can be used in the method according to the invention, schematically, Fig. 13 is a schematic side view of a production line comprising the device for carrying out the method according to the invention, Fig. 14 is the top view of the device shown in Fig. 13, fig. 15 - cross section along the line XV-XV according to Fig. 13, schematically, Fig. 16 - cross section along the line XVI-XVI according to Fig. 13, schematically, Fig. 17 - an alternative device for performing this method, schematically in side view, Fig. 18 is a cross-sectional view taken along the line XVIII-XVIII according to Fig. 17, Fig. 19 is an alternative device for performing this method schematically in a side view, Fig. 20 is a device in accordance with Fig. 19 schematically in a side view, Fig. 21 - a device for performing the method according to the invention, schematically in side view, Fig. 22 - a sectional view taken along the line XXII-XXII in Fig. 21, schematically.

Although the method of the present invention will be described with reference to disposable diapers, it is understood that the claimed method can be applied to any article provided with a hook and loop fastening system. Namely, this method is particularly useful for use with disposable items such as sanitary napkins with wings having hook-and-loop fasteners on the wings, underwear for adults with restraint and diaper-fastened diapers.

Figures 1 to 3 show the diaper 10. The diaper in the second embodiment consists of a liquid-impermeable back sheet 12, a liquid-permeable cover sheet 14 and an absorbent core arranged between them 16. The diaper 10 may also have an elastomer of the leg 18 positioned along the side rims of the diaper 10. The diaper 10 may be made of any material commonly used in this field. For example, the bottom sheet 12 may be a polyethylene film, while the cover sheet 14 may be made of a number of materials, such as natural fibers, synthetic fibers or a combination thereof.

It is only important that the material of the cover sheet 14 has exposed fibers that can attach to the hooks of the hook and loop fastening system. A suitable material for this purpose is spun bonded polypropylene nonwoven fabric, although the actual choice of materials will depend on the type and configuration of the hook members used in the hook and loop fastening system.

A first example of a typical hook-and-loop fastener system that can be used in the method of the invention includes a pair of polymer fastener members 20, where there is a first portion 22 attached in the first waist portion 24 of the diaper 10. As best shown in Figure 2, each fastener member 20 includes a second portion 26 from which a plurality of hook members 30 protrude. The hook members 30 are adapted to be connected to the loop fastener portion 32 located on the outer surface of the bottom sheet 12 in the second waist portion 34 of the diaper 10. Typically in use, the second waist portion 34 of the diaper lies on the abdomen of the user, while the first waist portion 24 lies on the user's buttocks. Naturally, the outer surface of the bottom sheet 12 can be made such that it allows the hook members 30 to be connected with sufficient retention force, so that there is no need to provide the diaper 10 with additional loop fastener parts 32.

The hook members 30 may be made of any suitable material and may have any size, shape and density of distribution that will allow the tabs to be securely fastened to the loop parts 32 of the fastener. For example, the hook members 30 may be

188 658 made of hook or mushroom shaped nylon. The appropriate hook fastener is sold under the name 3M ™ with designation code CS200.

As shown in Figs. 2 and 3, the first portion 22 of the fastener member 20 is permanently attached to the top sheet 14 of the diaper, for example with suitable adhesive, or by welding.

In figure 3, the fastener member 20 is shown in the storage position, i.e. in the desired position when the diaper 10 moves along the production line, which the fastener member 20 retains when packaging the diaper 10. In the storage position, the region of the top sheet 14 containing the fastener member 20 is in the opposite position, as a result, the hook members 30 protruding from the second portion 26 of the fastener member 20 are in contact with the outer surface of the cover sheet 14.

According to the present invention, when the hook members 30 of the fastener contact the outer surface of the cover sheet 14, the hook members 30 of the second part 26 and the surface of the cover sheet 14 are displaced in a direction parallel to the surface of the cover sheet 14. It has surprisingly been noticed that the mutual displacement of these parts clearly increased the holding force between the hook members 30 and the outer surface of the cover sheet 14 compared to the holding force obtained without mutual displacement. In this regard, the term "holding force" means peel strength. The desired value of the holding force corresponds to the value capable of holding the fastener member in the storage position during the passage of the product along the production line and during its packaging, although it does not necessarily have to be as great as the holding force between the hook and loop parts in a conventional hook and loop fastener.

Regardless of the particular theory or mechanism, it is assumed that the mutual displacement of the hook members and the surface of the products in a direction parallel to the surface of this product causes jumping and holding back between the fibers and loops of the material, thus creating a connection.

Before describing the device suitable for carrying out the method according to the present invention, a description will be given of the second embodiment of the fastening system which is used with the absorbent article shown in Figs. 4 to 6.

Thus, the second embodiment of the hook and loop fastener that can be used in the method of the present invention includes a pair of fastening members 20 in the form of flexible, elongated, rectangular polymer fastener tabs made, for example, of nonwoven material. Each tab has a first portion 122 in the form of a first tip portion attached to the first waist portion 24 of the diaper 10. As most clearly shown in Fig. 5 each tab has a second portion 126 in the form of a distal portion of the tip that, in the diaper standby position 10, i.e. in the position immediately prior to attachment to the wearer's body, protrudes beyond the edge of the diaper 10. The distal portion of the tip of the tab has a backing 28 from which numerous hook members protrude. 30. As in the diaper 10 according to fig. 1 the hook members 30 are adapted to be connected to the loop fastener portion 32 located on the outer surface of the bottom sheet 12 in the second waist portion 34 of the diaper. Naturally, if the outer surface of the bottom sheet made it possible to connect the hook members 30 with sufficient retaining force, there would be no need to provide the diaper with additional loop parts 32.

According to FIGS. 5 and 6, the first portion 122 of the tip member 20 may be enclosed in a pair of flaps 36, where one flap 36 adheres to the outer surface of the bottom sheet 12 and the second flap 36 adheres to the outer surface of the top sheet 14. Alternatively, the first end portion of the flap may be uniform and may protrude between the top sheet 14 and the bottom sheet 12.

In Figure 6, the fastener member 20 is shown in the storage position, i.e. in the desired position when the diaper 10 passes along the production line that the flap retains when the diaper is packed 10. In the storage position, the distal portion of the tip tip 126 is folded into the first tip portion 122, as a result whereby the hook members 30 protruding from the sleeper 28 contact the outer surface of the cover sheet 14. According to the present invention, after the hook members 30 and the fastener tab are in contact

188 658 with the outer surface of the top sheet 14, the distal tip portion and the surface of the top sheet 14 move in a direction parallel to the surface of the top sheet 14.

In a further example, not shown, the invention may be used with buttoned diaper pants. Such articles have a shape corresponding to the shape of the diaper shown in Figures 1 and 4, except that the loop part 32 of the fastener forms part of the top sheet 14 in the second waist region of the diaper. In other words, the loop part 32 of the fastener may be in the form of tabs fixed in the corner regions of the second waist part 34, or the cover sheet 14 itself may serve as such loop parts of the fastener. For diaper pants, the storage position is assumed when the fastener members 20 in the first waist portion 24 engage with the loop portion or fastener parts in the second waist portion 34. This storage position therefore corresponds to the use position of the diaper pants until they are detached by disconnecting the first part 24 and the second part 34 of the waist.

It is common to all embodiments of this invention that after taking up the storage position, the second portion 26, 126 of the fastener member 20 and the surface of the article that contacts the second portion 26, 126 are mutually displaced in a direction parallel to the surface of the article. In this regard, the term "article surface" means any part of the article with which the fastener member 20 is in contact with the storage position, including any loop fastener member.

The remaining drawings show a device for carrying out the method according to the invention. Thus, Figure 7 schematically shows a production line for making diapers. The rectangles symbolize the bottom sheet 12, the top sheet 14 and the absorbent core 16, and these parts are fed to the first station 38, where the top sheet 14 and the bottom sheet 12 are joined together with the absorbent core 16 sandwiched between them. Then the partially connected article goes to the second station 40, where the fastening members 20 are attached. When the fastening members 20 are attached in the storage position as shown in Figures 3 and 6, the partially finished product directly goes to the third station 42, where the second parts are partially displaced. fastener members and cover layer for the partially finished diaper. After these parts are moved together, the diaper passes through the fourth station 44, where subsequent finishing operations are performed. After leaving the fourth station 44, a ready-made, wrapped diaper appears.

It will be obvious to a specialist that the order of operations given above may be changed depending on the components of the product. For example, the top sheet 14 may be provided with fastener members 20 before being attached to the bottom sheet 12 and the absorbent core 16. In this case, operations at stations 40 and 42 will occur before the article moves to station 38, where the layered structure is formed.

Means for displacing remote parts of the tip and the surface of the article with which the remote parts are in contact are shown schematically in Figs. 8A and 8B. Accordingly, a pair of cooperating rollers, a roller 46 with notch 50 and one roller 48 with a notch 52 can be used in the third station 42 (Fig. 7) in each side part of the article to which the fastener member tabs 20 are connected. articles depicted in fig. 1 and the 4th production line will be equipped with two pairs of rollers. In the illustrated example, the notch roller 46 has a circumferentially projecting notch 50 which slots loosely into the circumferential notch 52 of the roller 48 with the notch 52.

As shown in Fig. 9, the clearance between the notch 50 and the notch 52 is sufficient to pass the distal end of the second portion 126 of the layered sheet top member arrangement 20 with the bottom sheet 12 of the diaper shown in Fig. 4. Mutual displacement of the tip of the second fastener portion 126 and the outer surface of the cover sheet 14 is obtained due to the forced change of the position of the hook members 30 relative to the loop material of the top sheet when the distal portion of the tip of the second portion 126 of the fastener member 20 passes through a pair of rollers. The occurrence of reciprocal displacement will be clearly visible by comparing Figs. 10A and 10B.

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Figure 10A shows a second surface of the second part 26 of the fastener member 20 in a state prior to applying the method of the present invention in which mutual displacement is induced. The second surface of the second part 26 is generally flat, and the ends of the pairs of hook members 30 present in the second part 26 are separated by a distance y. After using the method of the invention as shown in Fig. 10B when moving the second surface of the second portion 26 relative to the surface of the article, the distance between the tips of the same adjacent hook members increases to the value z. After the fastener member 20 passes through the station in which there is mutual displacement, the elasticity of the fastener member 20 tends to return the hook members towards each other. This condition is further illustrated in Figure 11.

Figure 11 shows the fastener member 20 in the storage position in which the hook members 30 engage with the fibers or loops of the region of the outer surface of the cover sheet 14. Due to the fact that the second surface of the second part 26 of the fastener member 20 has been given bending to create the radius r at the third station 42, after the second part of the third station 42 has left and the flat state of the diaper has occurred, the hook members 30 of the fastener will exert compression forces marked with the letter F in the surface region of the cover sheet 14 in directions parallel to the surface. The compressive forces contribute here to the increase in the holding force of the fastener member 20 in the storage position.

The dimension and shape of the cooperating rollers is not essential here. Accordingly, in Figs. 12A to 12J, for example, various possible shapes of mating surfaces of notch 50 and notch 52 are illustrated. It should be noted that in some arrangements of the example shown in the notch 52 or along the notch 50, a rubber element 54 or similar elastic element . The roller 46 with notch 50 and the roller 48 with notch 52 may have diameters in the range of 20 to 200 mm, preferably about 100 mm. The notch 50 of the roller 46 can preferably extend radially about 6 mm.

Figures 13 to 16 schematically show the third station 42 of the diaper production line in one embodiment, where there is a pair of cooperating rollers 46, 48 located in the middle of the guide groove 56 in the table 58 of the production line. The guide groove 56 begins at the introduction surface of the pair of rollers 46, 48 and gradually expands and deepens until the pair of rollers 46, 48 approaches, where a through hole 60 is made in the table 50 through which the pair of rollers 46, 48 connects. the pair of rollers 46, 48 the shape of the guide groove 56 is a mirror image of the shape at the point of insertion. The guide groove 56 serves to guide the second part of the fastener tab of 1 part of the layered material, in contact with the hook members 30 in proper alignment, in the direction and through a pair of rollers 46, 48. The gradual convergence of the insertion surface of the groove 56 ensures that the fastener member 20 remains in the storage position after passing through a pair of rollers 46, 48.

It will be obvious to those skilled in the art that in the method of the present invention, it is only essential that the second portion of the fastener member 20 and the top sheet 14 change shape, thereby resulting in a better connection of the hook members 30 with the material of the top sheet 14 or any other surface of the article intended for connections to the fastener in storage position. It will therefore be obvious that the necessary interconnection of the parts passing through the third station 42 can be obtained by using a single roller, roll with a hump or notch cooperating with the stationary member. It is therefore obvious that reciprocal displacement can be achieved without the use of rollers, by using a suitably curved protruding plate causing displacement of the second portion of the fastener member 20, thereby causing the tips of at least some of the hook members to slide apart.

A further example of a device suitable for causing a mutual displacement of the second part of the fastener member 20 and the material with which it comes in contact is shown in Figs. 17 and 18, where endless belt 74 generally passes through the upwardly open channel 62 in the coiling block 64 mounted on the production line table . The belt 74 performs the same function as the notch roller 46 in the previously described embodiment, while the channel 62 imitates the operation of the roller 48 with the notch 52. Roller block 64 has

188 658 the inclined insertion surface 66 along which the second portion of the fastener member 20 and the associated portion of the layered material extends before being introduced into the channel 62 through the tape 74. When passing through the channel 62, the second portion of the fastener member 20 and the layered material are mutually displaced and thus the hook members Fastener tabs enter and attach to the surface material of the cover sheet 14. The outline of the fastener member 20 and the layered material inside the channel 62 is indicated by reference number 68 in FIG. 18. The winding block 64 has an inclined exit surface 70 ensuring smooth exit of the fastener member 20 and material from the channel 62.

The example described above is particularly useful for applying the method according to the invention to fastener members 20 of relatively large width. This is because the second part of the fastener member 20 forcibly adopts a position within the winding block 64 in which it covers almost the entire circumference of the strap 74. This can be compared with the rollers 46 with the notch 50 shown in Fig. 12, where the second part of the fastener member 20 covers only the semicircle.

Alternatively, a device for producing a satisfactory displacement of the second portion of the relatively wide fastener member 20 and the surface of the article using rollers is shown in Figs. 19 to 22. According to Figs. 19 and 20, a pair of rollers 46 with a notch 50 are arranged side by side on a common axis 72. The first of these rollers 46 cooperates with the first roller 48 with the notch 52 located before the rollers 46 with notch 50, while the second roller 46 with the notch 50 works with the second roller 48 with the notch 52 located behind the rollers 46 with the notch 50.

As can be seen from Fig. 20, this arrangement ensures reciprocal displacement between the first and second part of the fastener member 20 and the surface of the article that contacts it, even if the width of the second part is greater than the width of the notch 52 of one of the rollers 48 with the notch 52.

In the apparatus shown in Figs. 21 and 22, two pairs of cooperating rollers 46 with notch 50 and rollers 48 with a notch 52 are used, one pair being placed in front of the other. As can be seen from Fig. 22, the pairs of rollers 46, 48 are axial in relation to each other in such a way that within the scope of mutual displacement of the fastener member 20 and the surface of the article, the width w is created, and the width w is greater than the width of the notch 52 of each of the rollers 48 with the notch 52.

The invention is not limited to the examples above, but may vary within the scope of the appended claims. For example, the pair of rollers 46, 48 need not necessarily be located along the longitudinal axis of the diaper. In addition, both rollers 48 with a notch 52 can cooperate with one roll 46 with a notch 50. The shape of the notch 50 does not necessarily correspond to the shape of the notch 52. For example, the notch 50 can be rounded, while the notch 52 can have a rectangular cross-sectional shape. In addition, the roller 46 with a notch 50 or the rollers 46 can be placed under the roller 48 or the rollers 48 with a notch 52.

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