Holding device, absorbent article with such a device and method for manufacturing such a device

Description

Domaine Technique

[0001] This presentation concerns the field of restraint systems, in particular closure or anti-slip systems. More specifically, it focuses on restraint systems with retaining elements, particularly hook-and-loop restraint systems, where the retaining elements can be secured in loops or similar devices.

[0002] The presentation also covers the field of associated manufacturing processes and equipment.

[0003] The presentation still concerns the field of absorbent articles such as baby diapers or adult incontinence diapers including a self-fastening diaper retention system. Technique antérieure

[0004] Restraint systems comprising restraint elements supported by a base are well known and used in many fields of application, leading in fact to the realization of multiple forms of restraint elements, in particular hooks, intended to cooperate with each other or with complementary elements such as loops.

[0005] A recurring problem with such products concerns the restraint force applied, particularly given the greatly reduced dimensions of the restraint elements and the associated manufacturing constraints.

[0006] Indeed, the production of hooks with high resistance naturally leads to oversizing, which impairs the smoothness of the system and therefore the user experience, which is highly detrimental in certain areas, particularly in the area of ​​hygiene, and also leads to increased material consumption, which is detrimental in terms of cost, and also detrimental in terms of manufacturing, since the production of large parts leads to increased material cooling times, thereby increasing the occupancy time of production lines.

[0007] Document WO2017187097 discloses a restraint system comprising restraint elements supported by a base and exhibiting specific dimensional and geometric characteristics. Documents US5884374, US2005 / 060849, and FR3050624 present other examples of known restraint systems.

[0008] The present presentation aims to address these various issues by further improving existing systems. Présentation de l'exposé

[0009] According to a first aspect, the exposition relates to a restraint device as defined in claim 1, comprising a base extending along a longitudinal direction having a top face and a bottom face, a plurality of retaining elements extending from the top face of the base, each retaining element having a value in a first geometric dimension, said value in a first geometric dimension being one of: the height of the retaining elements, measured, for each retaining element, between a lower end of the retaining element connected to the base and a top end of the retaining element opposite the lower end, a dimension measured in a cross-sectional view perpendicular to the base, in particular a cross-sectional view perpendicular to the base and parallel to a transverse direction, a dimension measured in a view parallel to the base and at a distance from the retaining elements, a transverse dimension of the retaining elements, measured parallel to the top face of the base,a diametrical dimension of a portion of the retaining elements in the case where the retaining elements exhibit, at least in some portions, rotational symmetry, the thickness of a stem of the retaining elements or the width of the heads of the retaining elements, measured in a plane parallel to the upper face of the base, , the containment system having at least two containment zones and an intermediate zone located between the two containment zones and connecting the two zones

[0010] The retention elements in the first and second retention zones have values ​​along the first geometric dimension that are greater than the values ​​along the first geometric dimension of the retention elements in the intermediate zone. The assembly formed by the base and the retention elements has a weight between 10 and 120 g / m². Optionally, the retention zones and the intermediate zone form elongated, ribbon-like sections within a common ribbon, with the elongated sections and the common ribbon optionally elongated in the longitudinal direction. Optionally, the intermediate zone has at least one portion in which the base is thinner than the base thickness in the retention zones.

[0011] Optionally, in the intermediate zone, the base presents a weld line.

[0012] Optionally, in the intermediate zone, the base has voids.

[0013] Optionally in the intermediate zone, the base has a different state of matter than the state of matter it has in the retention zones.

[0014] Optionally, in the retention areas, the retention elements have a value according to the first geometric dimension which is substantially constant.

[0015] Optionally, considered in the direction from the first retention zone to the second retention zone, the intermediate zone successively presents retention elements whose value according to the first geometric dimension decreases and then retention elements whose value according to the first geometric dimension increases.

[0016] Optionally, the values ​​according to the first geometric dimension are measured according to a cross-sectional view perpendicular to the base, in particular a cross-sectional view perpendicular to the base and parallel to the transverse direction.

[0017] Optionally, the values ​​according to the first geometric dimension are measured according to a view parallel to the base and at a distance from the retaining elements.

[0018] Optionally, any straight line passing through at least one restraint element and extending in the direction from the first restraint zone to the second restraint zone, passing through said first and second restraint zones, must intersect at least three restraint elements, in particular at least five restraint elements in each of the first and second restraint zones. Alternatively, any straight line passing through at least one restraint element and extending in the direction from the first restraint zone to the second restraint zone, passing through said first and second restraint zones, must intersect at least one restraint element, in particular at least two restraint elements in the intermediate zone.It can be predicted that any straight line of the type defined above will intersect up to 70 restraint elements, or even 100 restraint elements in each of the first and second restraint zones and, optionally, up to 10 restraint elements, or even up to 30 restraint elements in the intermediate zone.

[0019] Optionally, at least in the containment zones, the containment elements are each formed of a rod surmounted by a head protruding from the rod, at least some of the containment elements in the intermediate zone being optionally without a head.

[0020] Optionally, at least in the containment areas, the containment elements are distributed according to a regular and repeating pattern.

[0021] Optionally the retaining elements are regularly distributed, for example in the form of rows or columns or even in a staggered pattern.

[0022] Optionally, the device further includes a substrate carrying the base, the substrate optionally comprising a layer of non-woven material.

[0023] Optionally, the assembly formed by the base and the retaining elements has a basis weight of between 30 and 80 g / m² (grams per square meter), in some cases between 30 and 70 g / m², and more specifically between 50 and 70 g / m². When the device includes a substrate, these basis weight values ​​are specifically verified for the assembly comprising the base and the retaining elements, without the substrate.

[0024] In particular, the base and the retention elements are present in the retention areas and in the intermediate zone.

[0025] In particular, the intermediate zone connects the two retention zones in a contiguous manner, without any space between the intermediate zone and, respectively, each of the two retention zones.

[0026] In particular, the first geometric dimension is a dimension along a given direction. As mentioned, this is, for example, the height of the retaining elements. However, it can also be a dimension other than height, for example, a transverse dimension of the retaining elements, measured parallel to the plane of the base. When the retaining elements exhibit rotational symmetry, at least in some portions, the first geometric dimension can be a diametrical dimension of those portions. These dimensions can, of course, be combined.Thus, in addition to the first geometric dimension, the retaining elements may have a second geometric dimension for which it is verified that the retaining elements arranged in the first and second retaining zones have values ​​according to the second geometric dimension which are greater than the values ​​according to the second geometric dimension of the retaining elements arranged in the intermediate zone.

[0027] In the intermediate zone, the retention elements have geometric characteristics that are degraded compared to the same characteristics of the retention elements in the retention zones, so that, at least for the first geometric dimension, the retention elements in the intermediate zone have lower values ​​than those in the retention zones.

[0028] However, to some extent, the intermediate zone retaining elements can contribute to the containment effort. They allow for fully effective retaining elements across the large areas that constitute the containment zones, without interruption between these fully effective zones. Furthermore, due to their reduced values ​​for the first geometric dimension, the retaining elements in the containment zone represent less mass than the retaining elements in the containment zones, thus enabling the creation of an effective, low-weight containment system.

[0029] The restraint system offers increased flexibility in the intermediate zone(s) compared to the restraint zones. Therefore, with the same number of restraint elements, the system is not only lighter but also more flexible than a system where all the restraint elements are undamaged (i.e., they are all like two restraint zones). This increased flexibility improves the quality of the restraint by allowing, for example, the system to better accommodate the movements of the person wearing an item equipped with such a restraint system.

[0030] In particular, in each retention zone, the value of the first geometric dimension of the retention elements varies within a determined range relative to a maximum value, for example between 80% and 100% of the maximum value, or even between 85% and 100% of the maximum value, or even between 90% and 100% of this maximum value.

[0031] In particular, the maximum value of the first geometric dimension can be substantially the same for both retention areas, meaning that this maximum value is the same for both retention areas with a tolerance of around 10% or even 5%.

[0032] Hereinafter, the "maximum reference value" for the first geometric dimension is the larger of the two maximum values ​​of the first geometric dimension observed for each of the two retention zones. As noted, these two maximum values ​​are normally close, so the maximum reference value is itself close to each of these two maximum values.

[0033] In contrast, in the intermediate zone, the value of the first geometric dimension can be significantly lower. Thus, for at least some of the retaining elements in the intermediate zone, the value of the first geometric dimension can be less than or equal to 30% of the maximum reference value, or even less than or equal to 50% of the maximum reference value, or even less than or equal to 60% of the maximum reference value. Here, "at least some of the retaining elements in the intermediate zone" means at least one retaining element, or at least 10%, 20%, or 40% of the retaining elements in the intermediate zone.

[0034] However, at least some of the intermediate zone retaining elements may have significant values ​​for the first geometric dimension. Thus, at least some of the intermediate zone retaining elements may have a value for the first geometric dimension of at least 5%, or even at least 10%, or at least 20% of the maximum reference value. Here, "at least some of the intermediate zone retaining elements" means at least one retaining element, or at least 10%, or at least 20%, or at least 40% of the intermediate zone retaining elements.

[0035] According to a second aspect, the disclosure relates to an absorbent article of the type baby diaper or adult incontinence diaper, the article comprising an assembly which includes two outer sheets and an absorbent core disposed between the outer sheets, the assembly being arranged so as to present a first diaper face, in particular a front face, and diaper sides, the article comprising a self-gripping retention system comprising receiving loops carried by one of the elements among the first diaper face and one of the diaper sides, and at least one retention device according to the disclosure, carried by the other of the elements among the first diaper face and said one of the diaper sides, such that the retention elements cooperate with the receiving loops when said at least one of the diaper sides is placed against the first diaper face to retain said at least one of the diaper sides vis-à-vis said first face.

[0036] The first side of the diaper can be the front of the diaper, that is, the outer side facing the lower abdomen of the person wearing it. The sides of the diaper can be the side panels or the ears, especially elasticated ears.

[0037] By "retaining at least one side of the layer vis-à-vis the first face," we mean closing that side of the layer against the first face, thus holding them together to prevent separation, and / or retaining that side of the layer against the first face while preventing or at least limiting their relative slippage. Optionally, the retention device may be arranged on a surface comprising loops, for example, on a region of the comfort strip (generally referred to in English as the "landing zone"), for example, near the lateral edges of the comfort strip.

[0038] According to a third aspect, the presentation concerns a manufacturing process for a restraint device as defined above, in which: A molding device is provided having a plurality of cavities formed hollow from a surface, the molding device optionally being a molding strip; a heated molding material is applied to said surface using an applicator, allowing the molding material to penetrate the cavities to form retaining elements. a process in which two separate adjacent flows of molding material are generated and applied to the surface in two application zones by causing the molding material to flow so that the two flows meet in a junction zone to form a base, so that the material penetrates more into the cavities present in the application zones than into the cavities present in the junction zone.

[0039] Here, "two adjacent flows" means "at least two adjacent flows". In particular, we can have three flows adjacent in pairs, and two junction zones, each between two adjacent flows.

[0040] Optionally, the applicator is an extrusion device comprising two adjacent channels separated by a partition, and the molding material is applied by moving the molding device and the extrusion device relative to each other in a longitudinal direction.

[0041] Optionally the channels can be of identical sections, the section of a channel being considered transversely to the direction of advancement of the material in the channel, that is to say normally being considered along the CD direction.

[0042] There may be more than two channels, separated in pairs by respective partitions, which may optionally be identical.

[0043] Optionally, the channels can be of different sections.

[0044] Optionally, the partitions may have different geometric characteristics. In particular, when the number of channels is three or more, the channels located on the outside in the CD direction may have different, and in particular smaller, cross-sections than the channels located on the inside. Optionally, the channels and the partition(s) separating them may be arranged symmetrically with respect to a plane of symmetry, which is in particular a plane defined by the MD direction and a direction perpendicular to the plane defined by the MD and CD directions, this plane of symmetry passing in particular through the midpoint of the applicator's width.

[0045] Optionally, before cooling the molding material, a substrate is applied against the plastic material applied to the surface of the molding device, so that said material is sandwiched between the surface of the molding device and the substrate.

[0046] Of course, it is possible to plan to bring the same molding material, or on the contrary different materials, into the different channels.

[0047] In particular, the cavities of the molding device which are used to form the retaining elements can all be analogous.

[0048] In particular, the cavities in the molding device used to form the retaining elements may be homogeneously distributed throughout the molding device (more precisely, in the molding device surface intended to receive the molding material). In this case, these cavities are present in the application zones and the junction zone with the same distribution or density. Due to creep mobilizing the material in the junction zone, this material penetrates the cavities in the junction zone less readily than those in the application zones. Consequently, retaining elements formed from cavities in the junction zone are degraded compared to those formed from cavities in the application zones.The application zones therefore serve to form retention zones of the restraint device, while the junction zone serves to form an intermediate zone.

[0049] Due to creep in the junction zone, the material may be present in this zone in a thinner layer than in the application zones, so that, in its part originating from the junction zone, the base of the retaining device may have a thinner layer than in its parts originating from the application zones. Brève description des dessins

[0050] Other features and advantages of the object of this presentation will emerge from the following description of an embodiment, given by way of non-limiting example, with reference to the attached drawings. [ Fig. 1 ] There figure 1 schematically represents equipment for the construction of a restraint system with restraint elements. Fig. 2 ] There figure 2 is an expansion of zone II of the figure 1 . [ Fig. 3 ] There figure 3 is a schematic cross-sectional view along line III-III of the figure 1 . [ Fig. 4 ] There figure 4 is a schematic partial view along arrow IV and line IV-IV of the figure 1 . [ Fig. 5 ] There figure 5 shows, in cross-section, an article comprising a restraint device as described herein. Fig. 6 ] There figure 6 is a top view of the article from the figure 5 . [ Fig. 7 ] There figure 7 is an enlarged view of detail VII of the figure 5 . [ Fig. 8 ] There figure 8 is a partial view along arrow VIII of the figure 7 . [ Fig. 9 ] There figure 9 is a detail of a restraint element of the restraint system as described in this presentation. Fig. 10 ] There figure 10 shows an absorbent article comprising a retention device as described. Description détaillée

[0051] There figure 1 schematically presents an example of equipment for the implementation of a restraint system with restraint elements.

[0052] The apparatus as represented includes a molding strip 1 positioned on rotating drive means 2 comprising here two rollers 21 and 22, and a material distribution means or applicator 3 adapted to apply a molding material, for example plastic and / or elastic, onto a surface of the molding device.

[0053] Molding strip 1 is an example of a molding device.

[0054] The apparatus is used to manufacture a retaining device 5, which is demolded from the molding device using a roller 6.

[0055] The illustrated example is of the type described in document WO2017187097; it may be modified or supplemented as indicated in that document or in document FR 1914162. The illustrated example, comprising two rollers 21 and 22, is not limiting; the number and arrangement of the roller(s) may vary, particularly to adapt to the length of the molding strip 1 and the different stations of the equipment. For example, three rollers could be used, or even just one, such that the molding strip is arranged around the periphery of the single roller to form a sleeve or screen, according to commonly used English terms. In particular, only one of the two rollers may be driven in rotation by motorized means, for example, roller 21, the other roller 22 being free, i.e., without motorized means, and driven in rotation via the molding strip, itself driven by roller 21.

[0056] A longitudinal direction is defined relative to the direction of travel of the molding strip 1. This longitudinal direction is commonly referred to as the "machine direction" or "MD" in English. The longitudinal direction is designated by the MD axis in the figures.

[0057] A transverse direction, or "cross direction" or "CD" as it is known in English, is also defined, corresponding to a direction perpendicular to the longitudinal direction and extending parallel to the inner and outer faces of the molding strip. The transverse direction is designated by the axis CD in the figures.

[0058] The molding strip 1 as presented comprises an inner face 11 and an outer face 12, the inner face 11 being in contact with the rotating drive means 2, while the outer face presents the surface on which the molding material is applied by the applicator 3.

[0059] More specifically, the applicator 3 is positioned opposite the molding strip 1, spaced from the molding strip 1 so as to define an air gap e indicated on the figure 1 . The limit of the injected material on the external face 12 of the molding strip 1 is identified by reference A, corresponding to the rear front of the injected material on the molding strip 1 with respect to the direction of movement of the molding strip 1.

[0060] As can also be seen on the figures 1 And 4 , the molding strip 1 is provided with a plurality of cavities 13 allowing the production of retention elements of the retention device 5.

[0061] In this case, the cavities 13 shown on the figure 1 are each shaped to be used for making hook-type retaining elements. Thus, as can be seen more clearly on the figure 2 , each cavity defines a stem 14 extending from the outer face 12 to the inner face 11 of the molding strip 1 and a head 15 extending between the stem 14 and the inner face 11 of the molding strip 1.

[0062] In the illustrated example, the heads 15 of the cavities 13 open onto the inner face 11 of the molding strip 1. The cavities 13 are therefore through-cavities. This embodiment is not limiting; the cavities 13 can also be blind, and therefore not open onto the inner face 11 of the molding strip 1. Furthermore, the cavities can be of different shapes, including being without heads.

[0063] The portions of the cavities 13 forming the rods 14 typically extend in a direction perpendicular to the outer face 12 of the molding strip 1. The portions of the cavities 13 forming the rods 14 typically have a rotational geometry about an axis perpendicular to the outer face 12 of the molding strip 1, or a geometry having a plane of symmetry extending in a direction parallel to the direction of scrolling of the molding strip 1 and / or in a direction perpendicular to the direction of scrolling of the molding strip 1.

[0064] The portions of the cavities 13 forming the rods 14 have, for example, a generally frustoconical or cylindrical shape of rotation around an axis perpendicular to the external face 12 of the molding strip 1, and have a rounded shape at the junction with the external face 12 of the molding strip 1.

[0065] The portions of the cavities 13 forming the heads 15 typically extend radially or transversely with respect to an axis perpendicular to the outer face 12 of the molding strip 1, and may exhibit rotational symmetry about this axis perpendicular to the outer face 12 of the molding strip 1. The portions of the cavities 13 forming the heads 15 typically have a frustoconical or hexahedral shape, or are substantially frustoconical or hexahedral.

[0066] The portions of the cavities 13 forming the heads 15 can be linear or curved, for example forming portions curved towards the inner face 11 or towards the outer face 12 of the molding strip 1 extending from the portions of the cavities 13 forming the stems 14.

[0067] The portions of the cavities 13 forming the heads 15 may have a constant or variable thickness.

[0068] In the example shown in the figures, the portions of the cavities 13 forming the heads 15 extend radially around the portions of the cavities 13 forming the stems 14, and have a general disc shape, as can be seen in particular on the figure 2 which will be presented later.

[0069] The molding strip 1 may have on its inner face 11 or on its outer face 12 a particular texture such as grooves, a network of grooves or a network of passages forming vents or studs, or be smooth or substantially smooth.

[0070] The molding strip 1 can be formed by a superposition of several strips, and is therefore not necessarily monobloc or monomaterial.

[0071] The molding strip can have, in the transverse direction CD, a width of between 5 and 3000 mm.

[0072] The molding device comprising a molding strip, as just described, is an example of a molding device. Other types of devices could be envisaged, for example, those comprising plates with molding cavities, these plates being able, for example, to advance step by step.

[0073] Another type of molding device is also possible, for example, one with rollers in which the mold cavities are directly formed. These could be solid rollers, machined to present the mold cavities, or discs stacked to form a roller, the mold cavities being formed by machining the edges of the discs and / or by cutting the edges of the discs, for example by laser, water jet, or electrical discharge machining (EDM), particularly wire EDM. Of course, the discs can be stacked by alternating solid discs with perfectly circular or cylindrical edges with discs whose edges have cutouts.

[0074] There figure 2 represents the molding material once injected into the molding strip 1. We represent on the figure 2 a side view (cross-section) of the material in the cavities 13 of the molding strip 1.

[0075] As can be seen on the figure 2 , the molding material enters the molding strip so as to fill the cavity 13, thus forming a rough outline of retaining elements, in this case a rough outline of a stem and head for hook retaining elements.

[0076] A layer of molding material is also deposited on the outer face 12 of the molding strip 1 so as to form a base for the retaining device, the thickness of this layer of molding material being determined by the gap e between the outlet of the applicator 3 and the molding strip 1.

[0077] The air gap typically has a thickness of less than 700 micrometers, or typically between 5 and 500 micrometers, or even between 8 and 100 micrometers.

[0078] In the example shown, the cavities 13 of the molding strip 1 are through-holes. The apparatus may then include an element such as a scraper 4 positioned to scrape the inner face 11 of the molding strip 1 to remove excess molding material as needed.

[0079] The injection of molding material into the molding strip 1 by the applicator 3 thus makes it possible to form retaining elements in the cavities 13, the whole thus forming a strip 100. These can be finished retaining elements or preforms which will then be subjected to a forming or calendering step for their finalization, as mentioned in patent application WO2017187097. Here, injection means the action of shaping a molding material by melting, for example, distribution, supply, molding, injection, extrusion.

[0080] With reference to figures 3 et 4 We will now describe applicator 3. This applicator is, in this case, an extrusion device comprising at least two adjacent channels, separated by a partition. In the example shown, applicator 3 comprises three aligned channels 3A, 3B, and 3C, with channel 3B located between channels 3A and 3C, from which it is separated by partitions 3' and 3'.

[0081] For example, the applicator's application width L0 is between 70% and 100% of the effective width LB of strip 1. Here, the term "application width" refers to the transverse distance, measured along the CD direction, between the furthest edges of the application channels. It is thus measured between an outer lateral edge of channel 3A and the opposite outer lateral edge of channel 3C. In this case, the three channels 3A, 3B, and 3C have the same width L1, which is, for example, between 1 and 60 mm, in some cases between 2 and 50 mm, and particularly between 3 and 30 mm. This width L1 is measured at the channel outlets. In this case, the 3' and 3" partitions have the same width L2, also measured on the applicator's exit face, which is, for example, between 0.5 mm and 15 mm, and in particular between 0.5 mm and 10 mm. Preferably, the width L2 is less than or equal to the width L1.

[0082] The outputs of channels 3A, 3B, 3C in this case have the form of rectangular openings of width L1 and height e1. The ratio e1 / L1 is generally less than or equal to 2, or even less than or equal to 1, or even, as in the example shown, less than or equal to 0.5.

[0083] The outlets of the canals could have different shapes, for example being square, circular, oval, elliptical, or even dog bone shaped, that is to say a generally rectangular shape, but with the ends swollen forming one or two lobes.

[0084] On the figure 4 Channels 3A, 3B, and 3C are shown in a schematic cross-section taken in plane IV-IV of the molding material advance, while the molding strip is shown in external view along arrow IV. It can be seen that, at the outlet of the channels, three separate flows of molding material, 3A, 3B, and 3C, are formed. These three flows apply the molding material to surface 12 of strip 1 in three application zones ZA, ZB, and ZC, which are the areas of the surface located at the channel outlets, in the direction of advance of the molding material in the channels, which corresponds to the MD direction.

[0085] The application of the molding material exiting the channels forms ribbons of molding material.

[0086] We can see that, upon exiting the channels and / or once applied to surface 12, the molding material flows laterally (in the direction CD). Indeed, once applied to strip 1, the material naturally tends to spread laterally to fill the space between two adjacent application areas. Due to the small width L2 of the partitions, the adjacent flows will naturally tend to merge. Thus, the areas of strip 1 located at partitions 3' and 3" form junction zones ZJ, ZJ' in which, due to the lateral flow of the molding material, the molding material ribbons applied at the exit of channels 3A, 3B, and 3C tend to merge. As indicated on the figure 4 by references f, the lateral creep phenomenon can take effect as soon as the channels exit, in the gap e, possibly before the molding material comes into contact with the surface 12.

[0087] The molding material, directly applied in the application zones ZA, ZB, and ZC, naturally fills the cavities 13 present in these zones as it advances in the MD direction. This is due to its velocity component and the outlet pressures of the channels, which are exerted primarily perpendicular to the plane of the surface 12. Conversely, in the junction zones ZJ and ZJ', this pressure is partly devoted to lateral creep, and its velocity component naturally acts primarily in the CD direction. Because of its lateral spreading, the molding material has less of a tendency to fill the cavities in the junction zones. Consequently, the parts of the retaining device originating from these junction zones exhibit retention elements that are degraded compared to those of the parts originating from the application zones, even though the cavities 13 in the junction and application zones are identical or similar.

[0088] That's what we see on the figure 5 This figure shows a retaining device which includes a base 51 and retaining elements 50 which extend from the upper face 511 of the base 51. In this case, the retaining device also includes a substrate 60 on the side of the lower face 512 of the base 51.

[0089] The upper face 511 and a lower face 512 of the base are typically parallel or substantially parallel, the upper face 511 being the face provided with the retaining elements 50.

[0090] We can see that the device has retention zones RA, RB, and RC, in which the retention elements are standard. This means that the retention elements in these retention zones have generally been correctly molded into the cavities. The retention elements in these zones all have approximately the same height h measured between the upper face 511 of the base 51 and their opposite upper end. This means, in particular, that the heights of these retention elements are all between 80% and 100%, or even between 85% and 100%, and even between 90% and 100% of the maximum height observed for these retention elements.

[0091] Here, the geometric dimension taken into account is the height of the retaining elements. Other geometric dimensions could be taken into account, for example the thickness of the rods of the retaining elements measured in a plane parallel to the top face of the base, or between the width of the heads of the retaining elements (if these are fitted with heads), also measured in a plane parallel to the top face of the base.

[0092] Between the containment zones RA, RB, and RC, the containment system has intermediate zones RJ and RJ'. It can be seen that, among the 50 containment elements, the 50A containment elements present in the intermediate zones RJ and RJ' are degraded compared to the others. In particular, their heights h' are lower than those of the containment elements present in the containment zones, and even, potentially, these heights vary quite significantly from one 50A containment element to another. This is even evident, especially on the figure 7 that the 50A retaining elements of the intermediate zones RJ and RJ' may be without a head, unlike those of the retaining zones RA, RB and RC.

[0093] Here again, height is only one of the geometric dimensions of the 50A retaining elements, which is taken into account when assessing their degradation compared to the retaining elements present in the containment zones. It is therefore understood that the difference in shape between the 50 retaining elements in the containment zones and the intermediate zones results not from different geometries of the cavities 13 of the strip 1, but from a non-uniform filling of these cavities by the molding material between the application zones and the junction zones.

[0094] On the figure 6 The retention zones RA, RB, and RC exhibit elongated ribbon-like shapes along the MD direction. The intermediate zones RJ and RJ' also have a ribbon-like shape, generally narrower (the width being measured in the CD direction). These intermediate zones display weld lines L and L', corresponding to the junction of the flows from channels 3A and 3B on one hand, and 3B and 3C on the other. In the intermediate zones, the base material may have a different material state than in the retention zones. In particular, the base material may have a homogeneous molecular orientation in the retention zones, for example, along the MD direction, whereas the molecular orientation may vary in the intermediate zones due to the creep of the molding material in directions with a non-zero component along the CD direction.However, we can see that these different zones form a single common ribbon R, with the intermediate zones connecting the retention zones.

[0095] As can be seen more clearly on the figure 6 The 50 retaining elements are distributed according to a regular and repeating pattern. Here, they are arranged in rows parallel to the CD direction and columns parallel to the MD direction, with the retaining elements of adjacent rows and columns staggered.

[0096] Moreover, we can see on the figure 4 that the cavities of the molding device are distributed according to this regular and repetitive pattern.

[0097] On the figures 5 And 7, we see that, when considering an intermediate zone RJ in the direction going from a retention zone RA to the adjacent retention zone RB, in particular a direction along the CD direction, the height of the retention elements decreases towards a central zone of the intermediate zone, then increases.

[0098] Base 51 typically has a thickness eb between 3 and 500 micrometers, or more specifically between 4 and 150 micrometers, or between 4 and 120 micrometers, or between 4.5 and 108 micrometers.

[0099] In retention zones RA, RB, and RC, the base thickness is constant or substantially constant. It is measured between two adjacent retention elements within the retention zones. "Substantially constant" means that the thickness varies by no more than 20%, or even 10%, from an average value.

[0100] Conversely, the thickness of base 51 can be reduced in the intermediate RJ and RJ' zones, as seen on the figures 5 And 7 . For example, it can decrease to represent 80%, or even 60%, or even 50% or less of the average thickness of the base in the retention areas.

[0101] As can be seen on the figure 8 It can even happen that the intermediate zone(s) PJ, RJ' exhibit voids 50B. These correspond to areas where either the creep joint between the two application zones of the molding material has not occurred locally, or the material has insufficiently penetrated the cavities of the molding strip and has formed chimney-shaped portions of the retaining elements, or the material has penetrated a cavity to form a degraded retaining element 50A, at the expense of its lateral creep, thus leaving a void at the base of this degraded retaining element. Voids 50B are generally small. In particular, the maximum dimension of a void, measured by the length of a segment running from one edge of the void to the other, parallel to the upper surface of the base, can be less than the minimum distance between two retaining elements.

[0102] The base 51 typically has a width between 1 and 3,000 millimeters, or more precisely between 2 and 400 millimeters, or even between 3 and 100 millimeters, the width of the base 51 being measured in the transverse direction relative to the longitudinal direction, for example in a direction parallel to the external face 12 of the molding strip 1. This width corresponds to the so-called useful width LB of the strip 1 of the molding device.

[0103] We describe certain geometric characteristics of a non-degraded retention element 50 (i.e., present in a retention zone) with reference to the figure 9 This retaining element is, in this case, hook-shaped, with a stem 52 and a head 53, which extends laterally from the stem. The overall height h of the retaining element 50 can be on the order of 80 to 1000 micrometers, in particular from 90 to 500 micrometers, and especially from 90 to 450 micrometers. The height h1 of the stem 52, measured from the upper face of the base 51 to the lower face of the head 53, can be on the order of 80 to 800 micrometers, in particular from 90 to 450 micrometers, or even from 90 to 300 micrometers. The height h2 of the head 53, measured between its lower and upper faces, between two planes parallel to the upper face of the base and tangent to said lower and upper faces, can be on the order of 5 to 200 micrometers, in particular from 10 to 100 micrometers.

[0104] As indicated, the assembly formed by the base and the retaining elements can have a weight between 10 and 120 g / m², in particular between 30 and 80 g / m², more particularly between 50 and 70 g / m².

[0105] The base itself can have a weight between 5 and 80 g / m², in particular between 10 and 60 g / m².

[0106] The following ratios can be observed in the retention areas: stem height on base height: 0.8 to 80, in particular 1.5 to 65; head height on base height: 0.1 to 30, in particular 0.3 to 22; stem height / weight of the assembly formed by the base and the retaining elements: 1 to 10 (in micrometers / g / m 2< ).

[0107] The height of the retaining element is measured by the length of a straight line segment starting from the center of the retaining element, at the level of the upper surface of the base (average level of this surface verified between two adjacent retaining elements in the area concerned) and arriving at its point of intersection with the outer envelope of the hook.

[0108] The base can be made of a single material, which can also be that of the retaining elements.

[0109] The demolding of the retaining device is typically carried out when the base is at a temperature lower than the melting temperature of the molding material, or lower than the heat deflection temperature of the molding material, for example when the inner face 11 of the molding strip 1 is at a temperature of approximately 45°C and the upper face 511 of the base 51 is at a temperature of approximately 75°C. The heat deflection temperature is commonly referred to by its English name "Heat Deflection Temperature" or "HDT".

[0110] The molding strip 1 is classically maintained, in the molding zone, at a temperature between HDT-30°C and HDT+10°C, in particular between 50°C and 120°C, in particular around 80°C, especially when the molding material is polypropylene or, generally, an ethylene copolymer.

[0111] Since base 51 can be extremely thin, the temperature of the molding strip, in the molding zone, can be slightly higher than HDT because the outer surface of the base (opposite the strip), which is in contact with the air, is at a lower temperature than the strip and, due to the thinness of the base, the inner face of the base and the retaining elements cool down as soon as the base separates from the molding strip.

[0112] The demolding stage can be followed by a forming stage, in which the second preforms are modified, particularly at the level of their head 53.

[0113] As indicated, the restraint device may include a substrate 60. This substrate is typically a layer of non-woven material, a plastic film, an elastic film, a composite film, or a thermally consolidated set of fibers and / or filaments. The substrate 60 is, for example, a web of fibers and / or filaments.

[0114] A nonwoven fabric is defined as a product obtained by forming a web of fibers and / or filaments that have been consolidated. Consolidation can be mechanical, chemical, or thermal and results in the presence of bonds between the fibers and / or filaments. This consolidation can be direct, meaning it is achieved directly between the fibers and / or filaments by welding, or it can be indirect, meaning it is achieved through an intermediate layer between the fibers and / or filaments, such as a layer of adhesive or a layer of binder. The term nonwoven fabric refers to a ribbon-like or web-like structure of fibers and / or filaments that are interwoven in a non-uniform, irregular, or random manner. A nonwoven fabric can have a single-layer or multi-layer structure. A nonwoven fabric can also be bonded to another material to form a laminate.A nonwoven fabric can be made from various synthetic and / or natural materials. Natural materials, for example, are cellulose fibers such as cotton, jute, flax, and similar materials, and may also include reprocessed cellulose fibers such as rayon or viscose. Natural fibers for a nonwoven material can be prepared using various processes such as carding. Synthetic materials, for example, include but are not limited to synthetic thermoplastic polymers, which are known to form fibers that include, but are not limited to, polyolefins, such as polyethylene, polypropylene, polybutylene, and similar materials; and polyamides, such as polyamide 6.6, polyamide 10, polyamide 12 and similar materials; polyesters, for example polyethylene terephthalates, polybutylene terephthalates, polylactic acids and similar materials, polycarbonates, polystyrenes, thermoplastic elastomers, polymeric vinyls, polyurethanes and mixtures and copolymers thereof. By way of example, nonwoven fabrics may be spunbond, spunmelt, thermally bonded carded, SMS, SMMS, SS, SSS, SSMMS, SSMMMS, air-through, or other types.

[0115] The substrate is not limited to a non-woven material, and can more generally be a non-woven material, a woven material, a knitted material, or a combination of several of these materials.

[0116] If the substrate 60 is a non-woven material, it can be activated prior to being bonded to the base. The substrate may comprise several distinct layers, including a support layer, which may itself be a non-woven material and may also be activated.

[0117] Plastic material is understood to mean a thermoplastic material, more particularly a polyolefin material based on homopolymer or copolymer.

[0118] The materials mentioned in document WO2017187097 can be used to form the base and retaining elements and, if present, the substrate. The substrate can be applied to the base as described in document WO2017187097.

[0119] The purpose of this presentation is to ensure that, while providing excellent containment properties, potentially over considerable widths, the containment system is particularly lightweight. Furthermore, it is highly flexible, especially in the intermediate zone(s). It forms a single unit, with the containment zones contiguous with the intermediate zone(s).

[0120] There figure 10 shows an absorbent article 200 of the type baby diaper or adult incontinence diaper. Typically, article 200 comprises an assembly that includes two outer sheets 210, 220 and an absorbent core 230 disposed between the outer sheets. The article has a first diaper face (front) FA, and diaper sides CC. The article includes a hook-and-loop retention system comprising receiving loops carried by one of the elements, either the first diaper face FA or one of the diaper sides CC. In this case, on the figure 10 , the 240 rectangle materialized on the first face of the FA layer includes such receiving loops and corresponds to a comfort band (generally designated in English as "landing zone").

[0121] The article also includes a retention device 5 as described herein. In this case, such a device 5 is arranged on each of the sides CC so as to cooperate with the receiving loops 240, which are carried here on the front face FA, in order to keep the article worn by the user closed.

Claims

1. A retainer device, comprising: - a base (51) extending along a longitudinal direction (MD) and having an upper face (511) and a lower face (512), - a plurality of retainer elements (50, 50A) extending from the upper face of the base, each retainer element having a value according to a first geometric dimension, said value according to a first geometric dimension being one among: - the height of the retainer elements (50, 50A), measured, for each retainer element, between a lower end of the retainer element connected to the base (51) and an upper end of the retainer element opposite to the lower end, - a dimension measured according to a sectional view perpendicular to the base (51), particularly a sectional view perpendicular to the base and parallel to the cross direction (CD), - a dimension measured according to a view parallel to the base (51) and at a distance from the retainer elements (50, 51A), - a cross dimension (CD) of the retainer elements (50, 50A), measured parallel to the upper face (511) of the base (51), - a diametrical dimension of a portion of the retaining elements (50, 50A) in the case where the retaining elements (50, 50A) have, in at least some portions, a symmetry of revolution, - the thickness of the rods of the retainer elements or the width of the heads (53) of the retaining elements (50, 50A), measured in a plane parallel to the upper face of the base (51), characterized in that: the retainer device has at least two retainer zones (RA, RB, RC) and an intermediate zone (RJ, RJ') disposed between the two retainer zones and connecting the two retainer zones, the retainer elements (50) disposed in the first and second retainer zones having values according to the first geometric dimension (h) which are greater than the values according to the first geometric dimension of the retainer elements (50A) disposed in the intermediate zone, wherein the assembly formed by the base (51) and the retainer elements (50, 50A) has a basis weight comprised between 10 and 120 g / m2.

2. The retainer device according to claim 1, wherein the retainer zones (RA, RB, RC) and the intermediate zone (RJ, RJ') form elongated zones in the form of tapes in a common tape (R), the elongated zones and the common tape being optionally elongated along the longitudinal direction (MD).

3. The retainer device according to claim 1 or 2, wherein the intermediate zone (RJ, RJ') has at least one part in which the base (51) has a thickness smaller than a thickness (eb) of the base in the retainer zones (RA, RB, RC).

4. The retainer device according to any of claims 1 to 3, wherein, in the intermediate zone (RJ, RJ'), the base (51) has voids (50B).

5. The retainer device according to any of claims 1 to 4, wherein, in the retainer zones (RA, RB, RC), the retainer elements (51) have a value according to the first geometric dimension (h) which is substantially constant.

6. The retainer device according to any of claims 1 to 5, wherein, considered in the direction going from the first retainer zone (RA) to the second retainer zone (RB), the intermediate zone (RJ) has successively retainer elements (50A) whose value according to the first geometric dimension decreases then retainer elements whose value according to the first geometric dimension increases.

7. The retainer device according to any of claims 1 to 6, wherein any straight line passing through at least one retainer element (50, 50A) and extending along the direction going from the first retainer zone (RA) to the second retainer zone (RB) while passing through said first and second retainer zones, intersects at least 3 retainer elements particularly at least 5 retainer elements in each of the first and second retainer zones and, optionally, at least 1 retainer element, particularly at least 2 retainer elements in the intermediate zone.

8. The retainer device according to any of claims 1 to 7, wherein, at least in the retainer zones (RA, RB, RC), the retainer elements (50) are each formed of a rod (52) surmounted by a head (53) protruding from the rod, at least part of the retainer elements of the intermediate zone being optionally devoid of a head.

9. The retainer device according to any of claims 1 to 8, wherein the assembly formed by the base (51) and the retainer elements (50, 50A) has a basis weight comprised between 30 and 80 g / m2, in some cases between 30 and 70 g / m2, more particularly between 50 and 70 g / m2.

10. The retainer device according to any of claims 1 to 9, further comprising a substrate (60) carrying the base, the substrate optionally comprising a layer of nonwoven material.

11. An absorbent item (200) of the baby diaper or adult incontinence diaper type, the item comprising an assembly which comprises two external sheets (210, 220) and an absorbent core (230) disposed between the external sheets, the assembly being arranged so as to present a first face of the diaper (FA), particularly a front face, and sides of the diaper (CC), the item comprising a hook-and-loop retainer system comprising receiving loops (240) carried by one of the elements among the first face of the diaper and one of the sides of the diaper, and at least one retainer device (5) according to any of claims 1 to 10, carried by the other of the elements among the first face of the diaper and said one of the sides of the diaper, so that the retainer elements cooperate with the receiving loops when said at least one of the sides of the diaper is placed against the first face of the diaper to retain said at least one of the sides of the diaper with respect to said first face.

12. A method for manufacturing a retainer device as defined in claim 1, wherein: - a molding device (1) is provided having a plurality of cavities (13) formed in a recessed manner from a surface (12), - a heated molding material (M) is applied on said surface, using an applicator (3) by allowing the molding material to penetrate into the cavities (13) to form retainer elements, characterized in that are generated two separate adjacent flows (FA, FB and / or FC) of a molding material (M) applied on the surface (12) in two application zones by causing the molding material to flow so that the two flows meet in a junction zone so as to form a base (51), so that the material penetrates further into the cavities present in the application zones than into the cavities present in the junction zone.

13. The method according to claim 12, wherein the applicator (3) is an extrusion device comprising two adjacent channels (3A, 3B and / or 3C) separated by a partition (3', 3"), and the molding material (M) is applied by moving the molding device (1) and the extrusion device (3) relative to each other in a longitudinal direction.

14. The method according to any of claims 12 to 13, wherein, before cooling of the molding material (M), a substrate (60) is applied against the plastic material applied on the surface of the molding device (1), so that said material is sandwiched between the surface of the molding device and the substrate. Retainer device comprising a base (51) extending along a longitudinal direction and a plurality of retainer elements (50, 50A) extending from the upper face of the base, each retainer element having a value according to a first geometric dimension. The retainer device has at least two retainer zones (RA, RB, RC) and an intermediate zone (RJ, RJ') disposed between the two retainer zones and connecting the two retainer zones, the retainer elements (50) disposed in the first and second retainer zones having values according to the first geometric dimension (h) which are greater than the values according to the first geometric dimension of the retainer elements (50A) disposed in the intermediate zone.