Improved holding device

Abstract

The holding device (1) comprises a base (10) and a plurality of holding elements (20) comprising a stem (30) with a head (40) on top; wherein, for each retaining element (20), in a projection in a plane formed by the upper surface (12) of the base (10), the lower end (34) of the stem (30) is inscribed within a first circle C1 having a center O1, the head (40) is inscribed within a second circle C2 having a center O2, said second circle being tangential to one end of the head (40) in the longitudinal direction (MD), the maximum dimension of the head (40) passing through the center of the circle C2 and extending in the longitudinal direction (MD) and / or the transverse direction (CD) is less than 80% of the diameter D2 of the second circle C2.

Description

Technical Field

[0001] The present invention relates to the field of retaining devices, in particular to the field of hook retaining devices. Background Art

[0002] Hook closure systems are well known and used in many fields of application, in fact leading to the production of various shapes of hooks or, more generally, of retaining elements intended to cooperate with each other or with complementary elements such as loops.

[0003] A recurring problem with such products relates to the retention force applied, particularly in light of the greatly reduced size of the hook and the associated manufacturing constraints.

[0004] In fact, the production of hooks with high resistance naturally leads to oversizing, which is detrimental to the smoothness of the system and therefore to the user's feelings, which is very disadvantageous in some areas, especially hygiene, and also leads to an increase in material consumption, which is disadvantageous in terms of cost and also disadvantageous in terms of manufacturing. A recurring problem also concerns maintaining the reproducibility of the elements, especially considering the global shortage of some raw materials.

[0005] The present disclosure aims to solve these various problems by proposing a retaining device whose geometry is simpler, more easily reproducible and, in particular in the case of global shortages of some raw materials, available from a wider range of raw materials. Summary of the invention

[0006] The invention therefore proposes a retaining device, for example for forming a self-gripping connection, comprising: - a base extending in a longitudinal direction and having an upper surface and a lower surface, a plurality of retaining elements extending on the upper surface of the base, each retaining element comprising a rod having a head at the top, for example arranged to cooperate with a counterpart so as to form a self-gripping connection; each rod comprising a lower end connected to the base and an opposite upper end from which the head extends, Wherein, for each retaining element, in projection into the plane formed by the upper surface of the base: -The lower end of the rod is inscribed in the first circle C1 with O1 as the center, The head is inscribed in a second circle C2 with O2 as the center and D2 as the diameter, the second circle being the smallest circle including the head, the second circle C2 being tangent to one end of the head along the longitudinal direction and / or the transverse direction So that: The maximum dimension of the head portion, which passes through the center O2 of the circle C2 and extends in the longitudinal direction and / or the transverse direction, is less than 80% of the diameter D2 of the second circle C2.

[0007] According to one example, the second circle C2 is included in the first circle C1 .

[0008] According to one example, the first circle C1 has a diameter D1, the distance between O1 and O2 is less than or equal to 50% of the diameter D1 of the first circle C1, in particular less than 30%, less than 25%, less than 20%, less than 15%, or less than 10%, and optionally, the distance between O1 and O2 is greater than or equal to 0%, or greater than 0%, or greater than 1%, or greater than 4% of the diameter D1 of the first circle C1. This structure means that the base and the head of the rod are centered or almost centered relative to each other, so that the rod of the retaining element is straight or substantially straight. This makes it possible to increase the mechanical strength of the retaining element and limit its deformation under shearing during its interaction with the fibers of the nonwoven fabric (nonwoven fabric).

[0009] According to one example, the second circle C2 being included in the first circle C1 means that at least 95% (particularly 98%, particularly 100%) of the surface of the circle C2 is included in the first circle C1.

[0010] According to one example, the distance between O1 and O2 is less than or equal to 50% of the diameter D2 of the second circle C2, in particular less than 30%, less than 25%, less than 20%, less than 15%, less than 12%, or less than 10%, and optionally, the distance between O1 and O2 is greater than or equal to 0%, or greater than 0%, or greater than 1%, or greater than 4% of the diameter D2 of the second circle C2. This structure also means that the base and the head of the rod are centered or almost centered relative to each other, so that the rod of the retaining element is straight or substantially straight. This makes it possible to increase the mechanical strength of the retaining element and limit its deformation under shearing during its interaction with the fibers of the nonwoven fabric.

[0011] According to an example, the distance between O1 and O2 is less than or equal to 100 μm, in particular less than or equal to 75 μm, less than or equal to 50 μm or less than or equal to 30 μm.

[0012] According to one example, the upper end of the rod is inscribed in a third circle C3 , said circle C3 being included in the second circle C2 .

[0013] According to one example, the nonwoven material is secured to the lower surface of the base.

[0014] According to one example, the ratio of the diameter D2 of the circle C2 to the diameter D1 of the circle C1 is comprised between 0.3 and 0.95, or more specifically between 0.5 and 0.9. Thus, the widest dimension of the head is smaller than the width of the lower end of the rod. The lower end or foot of the rod is thus reinforced, and the shearing or peeling forces applied by the nonwoven fabric are dispersed to limit the deformation of the rod at the level of its lower end.

[0015] According to one example, the retaining element has a hooking height Ha comprised between 30 and 120 micrometers, more particularly between 30 and 70 micrometers, even more particularly between 40 and 60 micrometers.

[0016] According to one example, the retaining element has a hooking dimension Da greater than 40 microns, in particular greater than 60 microns, and / or less than 120 microns, in particular less than 100 microns. The hooking dimension Da corresponds to the maximum direction between the upper end 32 of the rod 30 and the outer radial end of the head 40, which is measured in the radial direction relative to the central axis of the rod 30. According to one example, the retaining element has at least one hooking dimension Da, and the radial direction is the machine direction and / or the transverse direction. According to one example, the retaining element has at least two hooking dimensions Da, one of which has a radial direction along the machine direction and the other has a radial direction along the transverse direction. According to one example, the retaining element has at least two hooking dimensions Da, one of which has a radial direction along the transverse direction and the other has a radial direction along the transverse direction.

[0017] According to one example, the head has a thickness Hh comprised between 30 and 70 microns, in particular between 40 and 60 microns.

[0018] According to one example, the rods have a height Ht comprised between 150 and 330 micrometers, in particular between 200 and 300 micrometers.

[0019] According to one example, the ratio of the thickness Hh of the head to the height Ht of the stem is between 0.05 and 0.3, or more particularly between 0.1 and 0.25. Thus, the stem of the retaining element is reinforced, which limits deformations and optimizes performance (for example peeling and / or shearing performance).

[0020] According to one example, the ratio of the hook height Ha to the height Ht of the rod is between 0.05 and 0.4, in particular between 0.05 and 0.3, more particularly between 0.1 and 0.25. This configuration makes it easier for the fibers and / or filaments of the counterpart (in particular the nonwoven counterpart) to pass during engagement with the counterpart, while allowing sufficient grip of the fibers and / or filaments of the counterpart.

[0021] According to one example, in a side view along the longitudinal direction and / or the transverse direction, the rod has a proximal portion extending from a lower end of the rod, a distal portion extending from an upper end of the rod, and a middle portion arranged between the proximal portion and the distal portion, and the distal portion and the proximal portion have a curvature greater than the curvature of the middle portion relative to a straight line perpendicular to the longitudinal direction and the transverse direction.

[0022] According to one example, in a side view along the longitudinal direction and / or the transverse direction, in a view projected in a plane perpendicular to the side view, the rod has two opposite edges (here two opposite outer edges), wherein at least one of the two edges includes a curvature having one inflection point, or two inflection points, or three inflection points or more (for example, ten inflection points), and these inflection points are different; in some cases, each of the two edges includes a curvature having one inflection point, or two inflection points, or three inflection points or more (for example, ten inflection points), and these inflection points are different.

[0023] According to one example, in a side view along the longitudinal direction and / or the transverse direction, and in a view projected in a plane perpendicular to the side view, the rod has two opposite edges (here two opposite outer edges), wherein at least one edge (in some cases both edges) has a general shape of a wave or an inverted wave or an S or an inverted S.

[0024] According to one example, in a side view along the longitudinal direction and / or the transverse direction, the holding device has a ratio between the size of the upper end of the rod and the size of the lower end of the rod, the ratio being comprised between 0.3 and 0.75, or in particular between 0.3 and 0.65, or more particularly between 0.35 and 0.55, or even more particularly between 0.35 and 0.5. This structure of the rod makes it particularly possible to facilitate demoulding while maintaining a good ability to hold the fibers of the nonwoven fabric and reducing the material consumed.

[0025] According to one example, the retaining device is intended to cooperate with the ring to form a contact closure. According to one example, along the longitudinal direction and / or the transverse direction, the total number of hooking portions 42 or flanges 42 is included between 1 and 4 (including 1 and 4), in some cases between 1 and 3 (including 1 and 3), or between 2 and 4 (including 2 and 4), or between 2 and 3 (including 2 and 3). According to another example, at least two or at least three hooking portions are connected to each other in a continuous manner, in particular all the hooking portions are connected to each other in a continuous manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The invention and its advantages will be better understood on reading the following detailed description of different embodiments of the invention given as non-limiting examples.

[0027] [ Figure 1 ] Figure 1 A holding device according to one aspect of the invention is schematically shown.

[0028] [ Figure 2 ] Figure 2 is a top view of the retaining element.

[0029] [ Figure 3 ] Figure 3 Another top-down scale view of the retaining element is shown.

[0030] [ Figure 4 ] Figure 4 is a detailed scale drawing of the holding components.

[0031] [ Figure 5 ] Figure 5 is a detailed scale drawing of another example of a retaining element.

[0032] [ Figure 6 ] Figure 6 is a detailed scale drawing of another example of a retaining element.

[0033] In all the drawings, common elements are denoted by the same reference numerals. DETAILED DESCRIPTION

[0034] Here is the reference Figures 1 to 6 A holding device is described.

[0035] The figures show a holding device 1 comprising a base 10. The base 10 generally has a strip-like shape extending in a longitudinal or machine direction MD and in a cross direction CD perpendicular to the longitudinal direction MD.

[0036] The longitudinal direction MD is the main direction of extension of the base 10. In terms of production, this therefore corresponds to the displacement direction of the holding device 1 in a tool for its manufacture or shaping.

[0037] The base 10 has a generally strip-like shape with a thickness T and has edges. The longitudinal direction MD is generally parallel to the edges of the base 10, which define the ends of the base 10 along the transverse direction CD.

[0038] The designations "upper" and "lower" are arbitrary and non-restrictive for the base 10 defining an upper surface 12 and a lower surface 14 opposite the upper surface. Within the framework of the present disclosure, the base 10 is represented as being arranged flat. However, it should be understood that the base 10 is generally flexible, so this description should not be interpreted in a restrictive manner.

[0039] The retaining device 1 comprises a plurality of retaining elements 20 extending from an upper surface 12 of a base 10. The retaining elements 20 are typically formed integrally with the base 10. The retaining elements 20 are typically adapted or formed such that the retaining device can cooperate with a ring to form a contact closure.

[0040] Each retaining element 20 comprises a stem 30 and a head 40 .

[0041] The rod 30 extends from the upper surface 12 of the base 10. This defines a lower end 34 of the rod 30 connected to the base 10, and an upper end 32 of the rod 30 opposite the lower end 34 of the rod 30, which is the part of the rod 30 farthest from the base 10.

[0042] The rod 30 can, for example, have a circular, oval, polygonal cross section or more generally any suitable shape. In particular, a rod 30 with a cross-shaped or "+ (plus sign)" cross section can be produced. Such a cross-shaped cross section generally has four ribs that are substantially evenly distributed (e.g. evenly distributed around the central axis of the rod 30 and extending radially around the central axis of the rod 30). More generally, the rod 30 can, for example, have an oval or square or rectangular cross section, or according to the general shape of a star, with X evenly distributed arms, X being between 3 and 10, each arm having a proximal end and a distal end, the proximal ends of each arm being connected, and the distal ends of the arms being spaced apart from each other at the same angle.

[0043] The cross section of the rod 30 generally varies according to the height, which is measured along a direction perpendicular to the upper surface 12 of the base 10. According to one example, the cross section of the rod 30 decreases significantly or strictly from the lower end 34 of the rod 30 to the upper end 32 of the rod 30.

[0044] As an example, if the rod 30 is considered in a side view along the longitudinal direction MD and / or the transverse direction CD, the rod 30 has a proximal portion extending from a lower end 34 of the rod 30, a distal portion extending from an upper end 32 of the rod 30, and an intermediate portion arranged between the proximal portion and the distal portion.

[0045] According to one example, the cross-section of the rod 30 decreases from the lower end 34 of the rod 30 to the middle portion of the rod 30 and increases from the middle portion to the upper end of the rod.

[0046] The middle portion can, for example, have a constant cross-section or can have a decreasing cross-section in the direction from the base 20 to the head 40 .

[0047] According to one example, the proximal portion and the middle portion are bounded from each other by a reversal of curvature, and / or the middle portion and the distal portion are bounded from each other by a reversal of curvature. In some cases, then the distal portion and the proximal portion generally have a greater curvature than the curvature of the middle portion relative to a straight line perpendicular to the longitudinal direction MD and the transverse direction CD. This shape of the rod 30 (i.e., the radius of curvature of the distal portion of the rod is smaller than the radius of curvature of the middle portion) enables a greater fiber or filament retention capacity to be provided to retain the corresponding portion of the ring.

[0048] In some cases, in a side view along the longitudinal direction and / or the transverse direction, in a view projected in a plane perpendicular to the side view, the limit between the proximal portion and the middle portion is defined by the presence of a lower inflection point along one of the two edges of the rod 30, or by the presence of a lower inflection point along each of the two edges of the rod 30, and / or the limit between the middle portion and the distal portion is defined by the presence of an upper inflection point along one of the two edges of the rod 30, or by the presence of an upper inflection point along each of the two edges of the rod 30. In some cases, a straight line connecting the upper inflection points forms the limit between the middle portion and the distal portion, and / or a straight line connecting the lower inflection points forms the limit between the proximal portion and the middle portion. In other cases, a straight line parallel to the base 10 passing through the inflection point closest to the head 40 forms the limit between the middle portion and the distal portion, and / or a straight line parallel to the base 10 passing through the inflection point closest to the base 10 forms the limit between the middle portion and the proximal portion.

[0049] According to one example, the height of the distal portion is less than the height of the middle portion and / or the proximal portion. According to one example, the sum of the height of the distal portion and the height of the middle portion is less than the height of the proximal portion. According to one example, the ratio of the height of the distal portion to the height of the proximal portion is less than 0.5, in particular less than 0.4, in particular less than 0.3, and / or greater than 0.05, in particular greater than 0.1. In some cases, the rod comprises one or several middle portions.

[0050] The ratio between the heights of the different parts makes it possible to adjust, among other things, the material consumption, the demoulding constraints and the mechanical properties for producing the rod. It will be appreciated that a reduced cross section can reduce the material required. For the same head shape, a rod having a reduced cross section at its distal end will, for example, improve the performance in terms of hooking, but the demoulding constraints will be increased compared to another rod having the same head shape without this feature.

[0051] Optionally, in a side view along the longitudinal direction MD and / or the transverse direction CD, the rod 30 has two opposite edges which are generally in a wavy or inverted wavy shape, or, for example, in an S or inverted S shape.

[0052] The head 40 extends from the upper end 32 of the rod 30. The head has at least one portion extending beyond the upper end 32 of the rod 30 to define a hooking portion 42 or flange suitable for engaging fibers and / or loops and / or complementary retaining elements to form a self-gripping connection. Thus, the head 40 generally has a maximum cross-section, its surface being strictly greater than the surface of the upper end 32 of the rod 30.

[0053] The head 40 of the retaining element 10 is usually made of a preform (not shown) produced by molding, the molding comprising at least one rod and optionally a head, the upper end of the rod and / or the head of the preform being deformed. The deformation is usually carried out by calendering, for example by hot calendering. The head 40 usually has an irregular shape, especially in the case of being obtained by calendering.

[0054] The holding device 1 according to the invention has holding elements of a specific geometry, which will be described below.

[0055] For each rod 30, the lower end 34 is considered to be a portion of the rod 30 that defines the thickness variation of the base 10 that results in the thickness increase. Thus, the lower end 34 of the rod 30 corresponds, for example, to a portion of the rod 30 that extends in a plane parallel to the plane formed by the upper surface 12 of the base 10 and that is a first plane above the upper surface 12 of the base 10 in a direction perpendicular to the upper surface 12 of the base 10. Thus, if the upper surface 12 of the base 10 is considered to be planar, the lower end 34 of the rod can be defined, for example, by a variation of curvature of the upper surface 12 of the base 10 upwards.

[0056] A first circle C1 is then defined in which the lower end 34 of the rod 30 is inscribed. By "inscribed circle" is meant the smallest circle capable of completely enclosing the section under consideration, here the section of the rod 30 in the plane defined by the upper surface 12 of the base 10 and corresponding to the lower end 34 of the rod 30. For this first circle C1, the center O1 and the diameter D1 are defined.

[0057] Then, a second circle C2 is defined in which the head 40 is inscribed and which is tangent to one end of the head 40 along the longitudinal direction MD. Therefore, this circle corresponds to the smallest circle that can completely surround the projection of the head 40 in a plane parallel to the upper surface 12 of the base 10 while being tangent to one end of the head 40 in the longitudinal direction. For this second circle C2, the center O2 and the diameter D2 are defined.

[0058] According to the side view of the retaining element under consideration, i.e. observed along a plane perpendicular to the transverse direction CD or along a plane defined by the longitudinal direction MD and an axis perpendicular to the transverse direction CD and the longitudinal direction MD, the end of the head 40 along the longitudinal direction MD is determined as the point farthest from the upper end of the rod.

[0059] It should be noted here that the longitudinal direction MD and the transverse direction CD are not identical. In the case where the head of the holding element of the holding device 1 is formed by a forming method, for example by calendaring, the direction of travel of the holding device in the tool will affect the geometry of the head of the holding element and will result in an expansion of the material along the transverse direction CD and a compaction of the material along the longitudinal direction. Thus, for example, the longitudinal direction MD can be distinguished from the transverse direction CD by the fact that the maximum dimension of the head along the transverse direction CD is greater than the maximum dimension of the head along the longitudinal direction MD.

[0060] A third circle C3 is then defined in which the upper end 32 of the rod 30 is inscribed, i.e. the smallest circle capable of completely enclosing the section under consideration, here the section of the rod 30 in a plane parallel to the upper surface 12 of the base 10 and corresponding to the upper end 32 of the rod 30. For this third circle C3, a center O3 and a diameter D3 are defined. When the circle C3 cannot be discerned from the top view of the retaining element 20, the dimensions that can be observed in the view projected in the plane of the base 10 along the transverse direction CD and / or in the side view along the longitudinal direction MD can be reported, in comparison with the other dimensions of the head 40 and of the lower end 34 of the rod 30.

[0061] In the holding device 1 according to the invention, the second circle C2 is included in the first circle C1. In other words, the first circle C1 completely surrounds the second circle C2.

[0062] In addition, the maximum dimension of the head 40 along the longitudinal direction MD is less than 80% of the diameter D2 of the second circle C2. In some cases, the maximum dimension of the head 40 along the longitudinal direction MD is within a range with a lower limit of 30%, or 40% or 50% or 55% and / or an upper limit of 80% or 75%.

[0063] This geometry of the retaining element 20 is advantageous in several respects. The proposed geometry makes it possible to obtain shear characteristics at least equivalent to those of conventional retaining elements. Moreover, this geometry is advantageous in terms of ease of production and therefore reduces the risk of the retaining element 20 acquiring dimensional drifts, in particular by obtaining a retaining element 20 according to the invention whose material forming the head 40 is less deformed after demoulding, in particular compared to the heads of retaining elements of the prior art, such as those described in patent application EP3448194. Furthermore, minimizing deformations and therefore displacements of material provides better repeatability.

[0064] Optionally, the retaining element 20 is such that the ratio between the diameter D3 of the third circle C3 and the diameter D1 of the first circle D1, that is to say the ratio between the upper end 32 of the rod 30 and the lower end 34 of the rod 30, is comprised between 0.3 and 0.75, or in particular between 0.3 and 0.65, or more particularly between 0.35 and 0.55, or even more particularly between 0.35 and 0.5. Such parameters make it possible to reduce the demoulding constraints of the rod 30 while ensuring the passage of the head during demoulding and to minimize the material required to produce the retaining element 20.

[0065] Optionally, the distance between the centers O1 and O2 measured in the projection in the plane defined by the upper surface 12 of the base 10 is less than 50%, or less than 30%, less than 25%, less than 20%, less than 15%, or less than 10% of the diameter D1. Optionally, the distance between the centers O1 and O2 measured in the projection in the plane defined by the upper surface 12 of the base 10 is greater than or equal to 0%, or greater than 0%, or greater than 1%, or greater than 4% of the diameter D1 of the first circle C1.

[0066] Optionally, the distance between the centers O1 and O2 measured in the projection in the plane defined by the upper surface 12 of the base 10 is less than 50% of the diameter D2, or less than 25% of the diameter D2, or more specifically less than 10% of the diameter D2. Optionally, the distance between the centers O1 and O2 measured in the projection in the plane defined by the upper surface 12 of the base 10 is greater than or equal to 0% of the diameter D2 of the second circle C2, or greater than 0% of the diameter D2 of the second circle C2, or greater than 1% of the diameter D2 of the second circle C2, or greater than 4% of the diameter D2 of the second circle C2.

[0067] Optionally, the distance between O1 and O2 is less than 100 μm, in particular less than 75 μm, or less than 50 μm or less than 30 μm, and / or greater than or equal to 0 μm, or greater than 0 μm. Therefore, when the retaining element 20 is mated with the annular counterpart, the displacement force of the head 40 is not directed along a preferred direction, but is substantially constant in multiple directions, with the result that an unintended release of the ring mating with the retaining element 20 is reduced, such as the release of the ring along a specific stress direction. Therefore, the shearing performance and the peeling performance are improved.

[0068] Optionally, the ratio of the diameter D2 of the circle C2 to the diameter D1 of the circle C1 is between 0.3 and 0.95, or between 0.5 and 0.9, or between 0.6 and 0.85, or between 0.6 and 0.8. Such a ratio makes it possible to obtain a retaining device that can be demoulded more easily and provides a good compromise between properly demoulding the retaining element 20 and obtaining a head 40 with sufficient material to ensure satisfactory hooking performance (especially in peeling and / or shearing), without unnecessarily increasing the amount of material required for the rod 30, especially the lower end 34 of the rod 30.

[0069] Alternatively, the lower surface 14 of the base 10 can be secured to a substrate such as a nonwoven material, for example by bonding or by partially encapsulating a woven material in the lower surface 14 of the base 10 .

[0070] The height H of each retaining element 20 is defined as the maximum dimension of each retaining element 20 from the upper surface 12 of the base 10 along a direction perpendicular to the upper surface 12 of the base 10 (i.e., a direction perpendicular to the longitudinal direction MD and the transverse direction CD). The different heights and thicknesses defined below will also be measured along this same direction.

[0071] For each retaining element 20, the height Ht of the rod 30 is defined as the distance between the upper surface 12 of the base 10 and the upper end 32 of the rod 30. Optionally, the rod 30 has a height Ht comprised between 150 and 330 microns, in particular between 200 and 300 microns.

[0072] For each retaining element 20, the thickness Hh of the head 40 is defined as the distance between the upper end 32 of the rod 30 and the upper end of the retaining element 20. The thickness Hh of the head 40 is, for example, between 30 and 70 microns, in particular between 40 and 60 microns.

[0073] Optionally, the ratio between the thickness Hh of the head 40 and the height Ht of the rod 30 is between 0.05 and 0.3, or more particularly between 0.1 and 0.25. Under this ratio, the head 40 is thin enough to be easily inserted into the annular counterpart, while having sufficient peeling and shearing resistance under cooperation with the annular counterpart.

[0074] For each retaining element 20, a hooking height Ha is defined, which is the distance measured in the height direction between the lower end of the head 40 and the upper end of the head 40. The hooking height Ha makes it possible in particular to define a space under the head 40 in order to retain fibers and / or filaments, such as fibers and / or filaments of a nonwoven fabric, during the application of a force. Advantageously, the size of this space is greater than the diameter of the nonwoven fibers intended to cooperate with the retaining element 20.

[0075] In the case where the hooking portion 42 or flange 42 of the head 40 extends radially relative to the head, for example Figure 6 , the hooking height Ha is equal to the thickness Hh of the head 40 .

[0076] In the case where the hooking portion 42 or the flange 42 of the head 40 is not substantially horizontal, e.g. Figure 5 oriented toward the base 10 as schematically shown in FIG. 1 , the hooking height Ha is measured as the distance between two straight lines, parallel to the longitudinal direction MD and the transverse direction CD, respectively, one straight line passing through the top of the head 40 and the other straight line passing through the lower end of the head, that is to say through the point of the hooking portion 42 or flange 42 closest to the upper surface 12 of the base 10 in the height direction. The hooking height Ha is then greater than the thickness Hh of the head 40.

[0077] In the proposed device, the retaining element 20 generally has a hooking height Ha comprised between 30 and 120 microns, more particularly between 30 and 70 microns, even more particularly between 40 and 60 microns. Such a hooking height makes it possible to improve the grip and retention of the counterpart (such as a ring).

[0078] Optionally, the ratio between the hook height Ha and the height Ht of the rod 30 is between 0.05 and 0.4, in particular between 0.05 and 0.3, more particularly between 0.1 and 0.25. Thus, the retaining element 20 having such characteristics has a head 40 that is thin enough to be easily introduced into the annular counterpart, while having sufficient resistance to peeling and shearing under cooperation with the annular counterpart.

[0079] The various measurements are performed, for example, by averaging the holding element 20 and at least four adjacent holding elements.

[0080] Optionally, the maximum dimension of the rod 30 at the lower end 34 is comprised between 110 and 900 microns, in particular between 350 and 550 microns. Thus, with such dimensions, the rod 30 is well anchored in the base 10, ensuring good rigidity when it cooperates with the fibers and / or the rings and / or the complementary retaining elements to produce a self-gripping connection.

[0081] According to a second aspect of the present invention, the holding device 1 comprises: a base 10 extending along the longitudinal direction MD and having an upper surface 12 and a lower surface 14, a plurality of retaining elements 20 extending on the upper surface 12 of the base 10, each retaining element 20 comprising a rod 30 topped with a head 40; each rod 30 comprising a lower end 34 connected to the base 10 and an opposite upper end 32 from which the head 40 extends, Therein, for each retaining element 20, in projection in the plane formed by the upper surface 12 of the base 10: - the lower end 34 of the rod 30 is inscribed in a first circle C1 centered at O1, The head 40 is inscribed in a second circle C2 with O2 as the center and D2 as the diameter, wherein the second circle C2 is the smallest circle including the head 40, and the second circle C2 is generally tangent to one end of the head 40 along the longitudinal direction MD and / or the transverse direction CD, in - the minimum distance between the corresponding edges of the two first circles C1 of the two lower ends 34 of adjacent rods 30 is at least greater than 50 micrometers, in particular greater than 70 micrometers, more particularly greater than 90 micrometers and / or less than 300 micrometers, less than 250 micrometers, more particularly less than 200 micrometers, and / or - In a projection in the plane formed by the upper surface 12 of the base 10, in a representative area with the retaining element 20, the occupancy rate of the first circle C1 of the retaining element 20 in said representative area is between 25% and 80%, in particular between 40% and 80%, in particular between 50% and 70%.

[0082] “Adjacent” means consecutive retaining elements along the same line formed by retaining elements 20 on the upper surface 12 of the base 10 , or the closest retaining elements 20 belonging to two consecutive lines.

[0083] A "representative area" is understood here to be an area comprising a plurality of substantially repeating patterns, for example between 5 and 10 patterns, typically 6 or 7 patterns. This area is typically observed from photographs obtained with a magnification of x100 using a digital microscope with the reference number "VHX 6000" from Keyence Corporation, and the measurements are obtained by means of the image analysis software of the digital microscope.

[0084] Thus, by this arrangement, the space between the lower ends 34 of the rods 30 of the retaining elements 20 and / or the occupancy of the lower ends 34 of the rods 30 of the retaining elements 20 is sufficient to keep the base 10 flexible while having peeling and shearing properties equivalent to existing products, or even improved in peeling properties thanks to the improved flexibility of the retaining device 1. Thus, the base 10 is flexible enough to be rolled up for transportation while having acceptable peeling and shearing properties without consuming too much material. Moreover, with this occupancy, a good flexibility of the retaining device 1 can be obtained, in particular when it is provided for hygienic applications, such as for absorbent articles, in particular open or closed diapers. Previous products with such a geometry that the first circle C1 is included in the second circle C2 or only a part of the second circle C2 is inscribed in the first circle C1 do not have such problems, but still have the problems mentioned above, in particular in terms of material consumption and user perception.

[0085] According to another example, the flexibility of the base 10 is improved by the thickness of the base 10 being comprised between 10 μm and 100 μm, in particular between 15 μm and 65 μm, in particular between 16 μm and 65 μm, or between 22 μm and 49 μm.

[0086] According to another example, for a product having a grammage of 15 g / m 2 and 120g / m 2 Between, especially at 20g / m 2 and 90g / m 2 In some cases between 26g / m 2 and 70g / m 2 The base 10 therebetween, the flexibility of the base 10 is further improved.

[0087] These different characteristics combine to produce a synergistic effect to improve the flexibility of the base 10 .

[0088] Then, the grammage of the nonwoven material is, for example, less than 80 g / m 2 , in some cases, is included in 5g / m 2 and 120g / m 2 Between 10g / m 2 and 70g / m 2 between.

[0089] Optionally, the third circle C3 is included in the second circle C2.

[0090] Typically, each retaining element 20 according to the present invention has a general shape in a side view along the longitudinal direction MD that is different from or similar to the general shape of the same retaining element 20 in a side view along the transverse direction CD. Typically, each retaining element 20 according to the present invention has a rod 30, which has a general shape in a side view along the longitudinal direction MD that is different from or similar to the general shape of the same rod 30 in a side view along the transverse direction CD. Typically, each retaining element 20 according to the present invention has a head 40, which has a general shape in a side view along the longitudinal direction MD that is different from or similar to the general shape of the same head 40 in a side view along the transverse direction CD. According to one example, Figure 4 and Figure 5 corresponds to the same retaining element 20 in the view along the transverse direction CD and in the view along the longitudinal direction MD, respectively, or Figure 4 and Figure 6 The same retaining element 20 corresponds in each case to the view along the transverse direction CD and in the view along the longitudinal direction MD.

[0091] Optionally, the number of retaining elements 20 per unit area is less than 1 cm2. 2 ) 600 retaining elements 20, in particular comprised between 160 and 340 retaining elements 20 per square centimeter.

[0092] In the present application, height and thickness are generally observed from photographs obtained with a digital microscope with reference number "VHX 6000" from Keyence Corporation at a suitable magnification, for example Figure 2 The magnification in the case was X500, and the measurements were obtained using the image analysis software of the digital microscope.

[0093] Generally, two types of self-gripping connections can be distinguished, one type in which the retaining elements cooperate with other retaining elements of the same type / nature or in the form of fibers and / or filaments and / or rings to form a mechanical connection, and the other type in which the retaining elements cooperate with a surface to form an adhesive connection (gecko type) or a connection using van der Waals forces. Although this second type of connection can in some cases be considered a connection called a self-gripping connection, the behavior and characteristics of this retaining element using van der Waals forces are completely different from those of retaining elements using mechanical connections. In fact, in the case of retaining elements using van der Waals forces, only the upper surface of the head ensures fixation to the receiving surface, while in the case of retaining elements for mechanical fixation, fixation is not ensured by the upper surface of the head, but by the lower surface of the head and the rod. According to one example, the device according to the invention is only suitable for forming a mechanical connection.

[0094] Although the present invention has been described with reference to specific exemplary embodiments, it is apparent that modifications and changes may be made to these examples without departing from the general scope of the invention as defined by the claims. In particular, the various features of the various illustrated / mentioned embodiments may be combined in additional embodiments. Therefore, the description and drawings should be regarded as illustrative rather than restrictive.

[0095] It is also obvious that all features described with reference to the method may apply to the device alone or in combination, in particular between the different aspects presented by the invention, and conversely all features described with reference to the device may apply to the method alone or in combination.

Claims

1. A holding device (1), comprising: - a base (10) extending in the longitudinal direction (MD) and having an upper surface (12) and a lower surface (14), - a plurality of retaining elements (20) extending on the upper surface (12) of the base (10), each retaining element (20) comprising a rod (30) having a head (40) at the top; each rod (30) comprising a lower end (34) and an opposite upper end (32), the lower end being connected to the base (10) and the head (40) extending from the upper end, Therein, for each retaining element (20), in projection in the plane formed by the upper surface (12) of the base (10): - the lower end (34) of the rod (30) is inscribed in a first circle C1 with a center O1, the head (40) is inscribed in a second circle C2 with a center O2 and a diameter D2, the second circle being the smallest circle including the head, the second circle C2 being tangent to one end of the head (40) along the longitudinal direction (MD) and / or the transverse direction (CD), So that: The maximum dimension of the head (40) passing through the center O2 of the circle C2 and extending along the longitudinal direction (MD) and / or the transverse direction (CD) is less than 80% of the diameter D2 of the second circle C2.

2. The holding device (1) according to claim 1, wherein: The second circle C2 is included in the first circle C1.

3. The holding device (1) according to any one of claims 1 or 2, wherein: The first circle C1 has a diameter D1, and the distance between O1 and O2 is less than or equal to 50% of the diameter D1 of the first circle C1, in particular less than 30%, less than 25%, less than 20%, less than 15%, or less than 10%, and optionally, the distance between O1 and O2 is greater than or equal to 0%, or greater than 0%, or greater than 1%, or greater than 4% of the diameter D1 of the first circle C1.

4. The holding device (1) according to any one of claims 1 to 3, wherein: The distance between O1 and O2 is less than or equal to 50% of the diameter D2 of the second circle C2, in particular less than 30%, less than 25%, less than 20%, less than 15%, less than 12%, or less than 10%, and optionally, the distance between O1 and O2 is greater than or equal to 0%, or greater than 0%, or greater than 1%, or greater than 4% of the diameter D2 of the second circle C2.

5. The holding device (1) according to any one of claims 1 to 4, wherein: The distance between O1 and O2 is less than or equal to 100 μm, in particular less than or equal to 75 μm, less than or equal to 50 μm or less than or equal to 30 μm.

6. The holding device (1) according to any one of claims 1 to 5, wherein: The upper end of the rod is inscribed in a third circle C3, and the circle C3 is included in the second circle C2.

7. The holding device (1) according to any one of claims 1 to 6, wherein: A nonwoven material (50) is secured to the lower surface (14) of the base (10).

8. Holding device (1) according to any one of the preceding claims, wherein: The ratio of the diameter D2 of the circle C2 to the diameter D1 of the circle C1 is between 0.3 and 0.95, or more particularly between 0.5 and 0.

9.

9. Holding device (1) according to any one of the preceding claims, wherein: The retaining element (20) has a hook height (Ha) between 30 and 120 microns, more particularly between 30 and 70 microns, even more particularly between 40 and 60 microns.

10. Holding device (1) according to any one of the preceding claims, wherein: The head (40) has a thickness (Hh) between 30 and 70 microns, in particular between 40 and 60 microns.

11. Holding device (1) according to any one of the preceding claims, wherein: The rods (30) have a height (Ht) between 150 and 330 microns, in particular between 200 and 300 microns.

12. Holding device (1) according to any one of the preceding claims, wherein: The ratio of the thickness (Hh) of the head (40) to the height (Ht) of the stem (30) is between 0.05 and 0.3, or more particularly between 0.1 and 0.

25.

13. Holding device (1) according to any one of the preceding claims, wherein: The ratio of the hook height (Ha) to the height (Ht) of the rod (30) is between 0.05 and 0.4, in particular between 0.05 and 0.3, more in particular between 0.1 and 0.

25.

14. Holding device (1) according to any one of the preceding claims, wherein: In a side view along the longitudinal direction (MD) and / or the transverse direction (CD), the rod (30) has a proximal portion extending from the lower end (34), a distal portion extending from the upper end (32), and a middle portion arranged between the proximal portion and the distal portion, and the distal portion and the proximal portion have a curvature greater than the curvature of the middle portion relative to a straight line perpendicular to the longitudinal direction (MD) and the transverse direction (CD).

15. Holding device (1) according to the preceding claim, wherein: In a side view along the longitudinal direction (MD) and / or the transverse direction (CD), and in a view projected in a plane perpendicular to the side view, the rod (30) has two opposite edges, at least one of the two opposite edges has a wavy or inverted wavy general shape or has an S or inverted S shape, and in some cases both edges have a wavy or inverted wavy general shape or has an S or inverted S shape.

16. Holding device (1) according to any one of the preceding claims, wherein: In a side view along the longitudinal direction (MD) and / or the transverse direction (CD), the retaining device (1) has a ratio between the dimensions of the upper end (32) of the rod (30) and the dimensions of the lower end (34) of the rod (30) which is between 0.3 and 0.75, or in particular between 0.3 and 0.65, or more in particular between 0.35 and 0.55, or even more in particular between 0.35 and 0.5.

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