Improved retention device

Abstract

The invention relates to a retention device (1) comprising a base (10), a plurality of retaining elements (20) comprising a shank (30) surmounted by a head (40); wherein, for each retaining element (20), in projection in a plane formed by the upper face (12) of the base (10), the lower end (34) of the shank (30) is inscribed inside a first circle C1 of centre O1, the head (40) is inscribed inside a second circle C2 of centre O2, the second circle being tangential to one end of the head (10) in the longitudinal direction (MD), the maximum dimension of the head (40) passing through the centre 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

IMPROVED RETAINER DEVICE Description Technical Field

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

[0002] Hook closure systems are well known and used in many fields of application, leading in fact to the production of multiple forms of hooks or more generally to multiple forms of retaining elements intended to cooperate mutually or with complementary elements such as buckles.

[0003] A recurring problem with such products concerns the retention force applied, particularly given the greatly reduced dimensions of the hooks and the associated manufacturing constraints.

[0004] Indeed, the production of hooks with high resistance naturally leads to oversizing, which affects the smoothness of the system and therefore the user experience, which is highly penalizing in certain areas, particularly in the field of hygiene, and also leads to increased material consumption, which is penalizing in terms of cost, and also penalizing in terms of manufacturing. A recurring problem also concerns the reproducibility of the retaining elements, particularly taking into account the shortages of certain raw materials on a global scale.

[0005] This presentation thus aims to respond to these different problems by proposing a retaining device whose geometry is simpler, more easily reproducible and could in particular be obtained from a larger wide spectrum of raw materials in view of the shortages of certain raw materials on a global scale. Statement of the invention

[0006] The present invention thus provides a retaining device, for example for producing a self-gripping connection comprising: - a base extending in a longitudinal direction, having an upper face and a lower face, - a plurality of retaining elements extending on the upper face of the base, each retaining element comprising a rod surmounted by a head, for example which head is arranged to cooperate with a counterpart in order 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, in which, for each retaining element, in projection in a plane formed by the upper face of the base: - the lower end of the rod fits into a first circle C1 with center 01, - the head is inscribed in a second circle C2 with center 02 and diameter D2, said second circle being the smallest circle comprising the head, which second circle C2 is tangent to one end of the head in the longitudinal direction and / or the transverse direction such that the maximum dimension of the head passing through the center 02 of the circle C2 and extending 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 an example, the second circle C2 is included in the first circle C1.

[0008] According to an example, the first circle C1 having a diameter D1, the distance between 01 and 02 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 01 and 02 is greater than or equal to 0% of the diameter D1 of the first circle C1, or greater than 0%, or greater than 1%, or greater than 4%. Such a structure implies that the base of the stem and the head are centered or almost centered relative to each other, and therefore that the stem of the retaining element is straight or substantially straight. This improves the mechanical strength of the retaining element, and limits its deformations under the effect of shear during its interactions with fibers of a nonwoven.

[0009] According to an example, it is understood by the second circle C2 is included in the first circle C1 that at least 95% of the surface of the circle C2 is included in the first circle C1, in particular 98%, in particular 100%.

[0010] According to one example, the distance between 01 and 02 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 01 and 02 is greater than or equal to 0% of the diameter D2 of the second circle C2, or greater than 0%, or greater than 1%, or greater than 4%. Such a structure also implies that the base of the rod and the head are centered or almost centered relative to each other, and therefore that the rod of the retaining element is straight or substantially straight. This makes it possible to improve the mechanical strength of the retaining element, and to limit its deformations under the effect of shear during its interactions with fibers of a nonwoven.

[0011] For example, the distance between 01 and 02 is less than or equal to 100pm, including less than or equal to 75pm, 50pm or 30pm.

[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] In one example, a non-woven material is bonded to the underside of the base.

[0014] According to one example, the ratio of the diameter D2 of the circle C2 and the diameter D1 of the circle C1 is between 0.3 and 0.95 or more precisely 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 shear or peeling forces applied by a nonwoven are distributed to limit the deformation of the rod at its lower end.

[0015] According to one example, the retaining elements have a gripping height Ha of between 30 micrometers and 120 micrometers, more particularly between 30 micrometers and 70 micrometers, even more particularly between 40 micrometers and 60 micrometers.

[0016] According to one example, the retaining elements have a gripping dimension Da, greater than 40 micrometers, in particular greater than 60 micrometers, and / or less than 120 micrometers, in particular less than 100 micrometers. The gripping dimension Da corresponds to the maximum direction between the upper end 32 of the rod 30 and an external radial end of the head 40, measured in a radial direction relative to a central axis of the rod 30. According to one example, the retaining elements have at least one gripping dimension Da and the radial direction is the machine direction and / or the transverse direction. According to one example, the retaining elements have at least two gripping dimensions Da, one of the gripping dimensions Da having a radial direction in the machine direction and the other of the gripping dimensions Da having a radial direction in the transverse direction.According to one example, the retaining elements have at least two attachment dimensions Da, one of the attachment dimensions Da having a radial direction along the transverse direction and the other of the attachment dimensions Da having a radial direction along the transverse direction.

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

[0018] According to one example, the rod has a height Ht which is between 150 micrometers and 330 micrometers, in particular between 200 micrometers and 300 micrometers.

[0019] According to one example, the ratio of the thickness Hh of the head and the height Ht of the rod is between 0.05 and 0.3, or more particularly between 0.1 and 0.25. Thus, the rod of the retaining element is reinforced, which makes it possible to limit deformations and to optimize performance, for example peeling and / or shearing.

[0020] According to one example, the ratio of the attachment height Ha and 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. Such a configuration makes it possible in particular to ensure, during engagement with the counterpart, easier passage of fibers and / or filaments of the counterpart, in particular of the non-woven counterpart, while allowing sufficient retention of the fibers and / or filaments of the counterpart.

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

[0022] According to one example, in side view in the longitudinal direction and / or the transverse direction in a view projected in the plane perpendicular to this side view, the rod has two opposite edges (here two opposite external edges) of which at least one of the two edges comprises a curvature with an inflection point, or two inflection points or three or more inflection points, for example ten inflection points, the inflection points being distinct, in certain cases, each of the two edges comprises a curvature with an inflection point, or two inflection points or three or more inflection points, for example ten inflection points, the inflection points being distinct.

[0023] According to one example, in side view in the longitudinal direction and / or the transverse direction in a view projected in the plane perpendicular to this side view, the rod has two opposite edges (here two opposite external edges) of which at least one, in certain cases both edges, has a general shape of a tilde or inverted tilde or of an S or inverted S.

[0024] According to one example, in side view in the longitudinal direction and / or the transverse direction, said retaining device has a ratio between the dimension of the upper end of the rod and the dimension of the end lower part of the rod 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 a structure of the rod makes it possible in particular to facilitate demolding, while maintaining a good capacity for holding non-woven fibers and reducing the material consumed.

[0025] According to one example, the retaining device is intended to cooperate with loops to achieve a contact closure. According to one example, depending on the longitudinal direction and / or the transverse direction, the total number of attachment portions 42 or lobes 42 is between 1 and 4 (inclusive), in certain cases between 1 and 3 (inclusive) or between 2 and 4 (inclusive) or between 2 and 3 (inclusive). According to another example, at least two, or at least three, of the attachment portions are connected to each other continuously, in particular all the attachment portions are connected to each other continuously. Brief description of the drawings

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

[0027] [Fig. 1] Figure 1 schematically illustrates a retaining device according to one aspect of the invention.

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

[0029] [Fig. 3] Figure 3 is another top view to scale of a retaining element.

[0030] [Fig. 4] Figure 4 is a detailed view to scale of a retaining element.

[0031] [Fig. 5] Figure 5 is a detailed view to scale of another example of a retaining element.

[0032] [Fig. 6] Figure 6 is a detailed view to scale of another example of a retaining element.

[0033] Throughout the figures, common elements are identified by identical numerical references. Description of the embodiments

[0034] A retaining device is described herein with reference to Figures 1 to 6.

[0035] The figures show a retaining device 1 comprising a base 10. This base 10 generally has the shape of a ribbon extending in a longitudinal direction or machine direction MD and a transverse direction CD perpendicular to the longitudinal direction MD.

[0036] The longitudinal direction MD is the main direction in which the base 10 extends. In terms of implementation, this thus corresponds to the direction of movement of the retaining device 1 in the tooling for its manufacture or shaping.

[0037] The base 10 has a general ribbon shape of thickness T, and having edges. The longitudinal MD is typically parallel to the edges of the base 10, which define the ends of the base 10 according to the transverse direction CD.

[0038] For the base 10, an upper face 12 and a lower face 14 opposite the upper face are defined, the designations "upper" and "lower" being arbitrary and not restrictive. For the purposes of this disclosure, the base 10 is shown as being arranged flat. However, it is understood that the base 10 is typically flexible, and that the description should therefore not be interpreted in a limiting manner.

[0039] The retainer 1 comprises a plurality of retaining elements 20 extending from the upper face 12 of the base 10. The retaining elements 20 are typically formed integrally with the base 10. The retaining elements 20 are typically adapted or formed so that the retainer can cooperate with loops to achieve a contact closure.

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

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

[0042] The rod 30 may for example have a circular, oval, polygonal section or more generally any suitable shape. In particular, a rod 30 may be produced having a cross-shaped or “plus” shaped section. Such a cross-shaped section typically has four ribs distributed substantially regularly, for example regularly, around a central axis of the rod 30, and extending radially around this central axis of the rod 30. More generally, the rod 30 may for example have an oval or square or rectangular section or in the general shape of a star with X regularly distributed arms, X being between 3 and 10, each arm having a proximal end and a distal end, the proximal ends of each of the arms being joined and the distal ends of the arms are all spaced from each other by the same angle.

[0043] The section of the rod 30 is typically variable according to the height, the height being measured in a direction perpendicular to the upper face 12 of the base 10. According to one example, the section of the rod 30 is predominantly or strictly decreasing from the lower end 34 of the rod 30 towards the upper end 32 of the rod 30.

[0044] By way of example, if the rod 30 is considered in side view in the longitudinal direction MD and / or the transverse direction CD, the rod 30 has a proximal portion extending from the lower end 34 of the rod 30, a distal portion extending from the 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 section of the rod 30 decreases from the lower end 34 of the rod 30 towards the intermediate portion of the rod 30 and increases from this intermediate portion to the upper end of the rod.

[0046] The intermediate portion may for example have a constant section, or may have a decreasing section in the direction from the base 20 towards the head 40.

[0047] According to one example, the proximal and intermediate portions are delimited from each other by an inversion of curvature, and / or the intermediate and distal portions are delimited from each other by an inversion of curvature. In certain cases, the distal portion and the proximal portion then typically have, with respect to a straight line perpendicular to the longitudinal direction MD and to the transverse direction CD, a curvature greater than the curvature of the intermediate portion. Such a shape of the rod 30 with a radius of curvature of the distal portion of the rod less than the radius of curvature of the intermediate portion makes it possible to offer a greater fiber or filament retention capacity for retaining a loop counterpart.

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

[0049] In one example, the height of the distal portion is less than the height of the intermediate portion and / or the proximal portion. In one example, the sum of the heights of the distal portion and the intermediate 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 stem comprises one or more intermediate portions.

[0050] The ratio between the heights of the different portions can in particular allow the material consumption for the production of the stem to be modulated, the constraints during demolding and the mechanical performance. It is understood that a reduced section allows the material required to be reduced. For the same head shape, a stem whose distal end has a decreasing section will, for example, improve performance in terms of grip, but will increase the constraints during demolding compared to another stem not having this characteristic and having the same head shape.

[0051] Optionally, in side view in the longitudinal direction MD and / or the transverse direction CD, the rod 30 has two opposite edges in the general shape of a tilde or inverted tilde, or for example in the shape of 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, in order to define a gripping portion 42 or lobe adapted to engage fibers and / or loops and / or complementary retaining elements to produce a self-gripping connection. The head 40 thus typically has a maximum section having a surface strictly greater than the surface of the upper end 32 of the rod 30.

[0053] The head 40 of the retaining elements 10 is typically made from a preform (not shown) resulting from molding comprising at least one rod, and optionally a head, the upper end of the rod and / or the head of the preform of which is deformed or are deformed. The deformation is typically carried out by calendering, for example by hot calendering. The head 40 typically has a non-regular shape, in particular in the case where it is obtained by calendering.

[0054] The retaining device 1 according to the present invention has retaining elements having a specific geometry, which are described below.

[0055] For each rod 30, the lower end 34 is considered to be the portion of the rod 30 defining a variation in thickness of the base 10 leading to an increase in the thickness. The lower end 34 of the rod 30 thus corresponds, for example, to the portion of the rod 30 which extends in a plane parallel to the plane formed by the upper face 12 of the base 10 and which is the first plane above the upper face 12 of the base 10 in the direction perpendicular to the upper face 12 of the base 10. Thus, if the upper face 12 of the base 10 is considered to be planar, the lower end 34 of the rod may, for example, be delimited by the variations in curvature of the upper face 12 of the base 10 upwards.

[0056] A first circle Cl is then defined in which the lower end 34 of the rod 30 is inscribed. By inscribed circle, we mean the smallest circle that can completely surround a section considered, here the section of the rod 30 in the plane defined by the upper face 12 of the base 10 and corresponding to the lower end 34 of the rod 30. For this first circle Cl, we define a center 01 and a diameter Dl.

[0057] A second circle C2 is then defined in which the head 40 is inscribed and which is tangent to one end of the head 40 in the longitudinal direction MD. This circle thus corresponds to the smallest circle which can completely surround a projection of the head 40 in a plane parallel to the upper face 12 of the base 10 while being tangent to one end of the head 40 in the longitudinal direction. For this second circle C2, a center 02 and a diameter D2 are defined.

[0058] The end of the head 40 is determined in the longitudinal direction MD as being the point furthest from the upper end of the rod in a side view of the retaining element considered, that is to say in view in a plane perpendicular to the transverse direction CD, or in a plane defined by the longitudinal direction MD and by an axis perpendicular to both the transverse direction CD and the longitudinal direction MD.

[0059] It is noted here that the longitudinal direction MD and the transverse direction CD are not equivalent. In the case of a retaining device 1 whose head of the retaining elements is formed by a forming process, for example by calendering, the direction of travel of the retaining device in the tooling will influence the geometry of the head of the retaining element, and will lead to a spreading of the material in the transverse direction CD and to a settling of the material in the longitudinal direction. Thus, for example, the longitudinal direction MD can be distinguished from the transverse direction CD because the maximum dimension of the head in the transverse direction CD is greater than the maximum dimension of the head in the longitudinal direction MD.

[0060] A third circle C3 is then defined in which the upper end 32 of the rod 30 is inscribed, that is to say the smallest circle that can completely surround a section considered, here the section of the rod 30 in the plane parallel to the upper face 12 of the base 10 and corresponding to the upper end 32 of the rod 30. For this third circle C3, a center 03 and a diameter D3 are defined. When the circle C3 is not discernible from a top view of the retaining element 20, it is possible to report the dimensions observable in a side view in the transverse direction CD and / or in the longitudinal direction MD in a view projected in the plane of the base 10 in comparison with the other dimensions of the lower end 34 of the rod 30 and of the head 40.

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

[0062] Furthermore, the maximum dimension of the head 40 in the longitudinal direction MD is less than 80% of the diameter D2 of the second circle C2, in certain cases, the maximum dimension of the head 40 in the longitudinal direction MD is in a range whose lower limit is 30%, or 40% or 50% or 55% and / or whose upper limit is 80% or 75%.

[0063] Such a geometry of the retaining elements 20 is advantageous in several aspects. The geometry as proposed makes it possible to obtain shear characteristics at least equivalent to those of conventional retaining elements. Furthermore, such a geometry is advantageous in terms of ease of production and thus reduces the risk of obtaining dimensional drifts of the retaining elements 20, in particular by obtaining retaining elements 20 according to the invention whose material forming the heads 40 has been less deformed after demolding, in particular in comparison with the heads of the retaining elements of the prior art, for example those described in patent application EP3448194. Furthermore, minimizing the deformation and therefore the displacement of material offers better reproducibility.

[0064] Optionally, the retaining elements 20 are such that the ratio between the diameter D3 third circle C3 and the diameter DI 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 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 demolding constraints of the rod 30, while ensuring passage of the head during demolding, and minimizing the material required for the production of the retaining elements 20.

[0065] Optionally, the distance between the centers 01 and 02 measured in projection in a plane defined by the upper face 12 of the base 10 is less than 50% of the diameter D1, or less than 30%, less than 25%, less than 20%, less than 15%, or less than 10%. Optionally, the distance between the centers 01 and 02 measured in projection in a plane defined by the upper face 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 01 and 02 measured in projection in a plane defined by the upper face 12 of the base 10 is less than 50% of the diameter D2, or even less than 25% of the diameter D2, or more precisely less than 10% of the diameter D2. Optionally, the distance between the centers 01 and 02 measured in projection in a plane defined by the upper face 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 D2 of the second circle C2.

[0067] Optionally, the distance between 01 and 02 is less than 100 pm, in particular less than 75 pm, or less than 50 pm or less than 30 pm and / or greater than or equal to Opm, or greater than Opm. Thus, when the retaining elements 20 cooperate with a loop counterpart, the displacement force of the head 40 is not oriented in a preferred direction but is substantially constant in multiple directions, which has the consequence of reducing the unexpected release of the loops cooperating with the retaining elements 20, for example the release of the loops in a particular direction of stress. Thus, the shear and peeling performances are improved.

[0068] Optionally, the ratio of the diameter D2 of the circle C2 and 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 which can be demolded more easily, and offers a good compromise between good demolding of the retaining elements 20 and obtaining heads 40 having sufficient material to ensure satisfactory gripping performance, in particular in peeling and / or in shearing, without unnecessarily increasing the quantity of material necessary for the rod 30 and in particular the lower end 34 of the rod 30.

[0069] Optionally, the lower face 14 of the base 10 may be secured to a substrate such as a non-woven material, for example by gluing or by partial encapsulation of the woven material in the lower face 14 of the base 10.

[0070] The height H of each retaining element 20 is defined as being the maximum dimension of each retaining element 20 from the upper face 12 of the base 10 in a direction perpendicular to the upper face 12 of the base 10, that is to say a direction perpendicular to the longitudinal direction MD and to the transverse direction CD. The different heights and thicknesses defined below will also be measured in this same direction.

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

[0072] For each retaining element 20, a thickness Hh of the head 40 is defined as being 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 micrometers and 70 micrometers, in particular 40 micrometers and 60 micrometers.

[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. With such a ratio, the head 40 is thin enough to easily insert into a loop counterpart while having sufficient peel and shear resistance in cooperation with a loop 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, for example of a non-woven fabric when a force is applied. Advantageously, the size of this space is greater than the diameter of the non-woven fibers intended to cooperate with the retaining elements 20.

[0075] In the case where the attachment portions 42 or lobes 42 of the head 40 extend radially relative to the head, as for example shown in FIG. 6, the attachment height Ha is equal to the thickness Hh of the head 40.

[0076] In the case where the attachment portions 42 or lobes 42 of the head 40 are not substantially horizontal, and are for example oriented towards the base 10 as shown schematically in FIG. 5, then the attachment height Ha is measured as being the distance between two straight lines each parallel to the longitudinal direction MD and to the transverse direction CD, one passing through the top of the head 40, and the other passing through the lower end of the head, that is to say through the point of the attachment portion 42 or of the lobe 42 closest to the upper face 12 of the base 10 according to the direction of the height. The attachment height Ha is then greater than the thickness Hh of the head 40.

[0077] In the device as proposed, the retaining elements 20 typically have a gripping height Ha of between 30 micrometers and 120 micrometers, more particularly between 30 micrometers and 70 micrometers, even more particularly between 40 micrometers and 60 micrometers. Such a gripping height makes it possible to improve the gripping and retention of counterparts such as loops.

[0078] Optionally, the ratio between the attachment 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. A retaining element 20 which has such characteristics thus has a head 40 which is sufficiently thin to be easily introduced into a loop counterpart while having sufficient resistance to peeling and shearing in cooperation with a loop counterpart.

[0079] The different measurements are for example carried out by an average taken on a retaining element 20 and at least 4 adjacent retaining elements.

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

[0081] According to a second aspect of the invention, the retaining device 1 comprises: - a base 10 extending in a longitudinal direction MD, having an upper face 12 and a lower face 14, - a plurality of retaining elements 20 extending on the upper face 12 of the base 10, each retaining element 20 comprising a rod 30 surmounted by 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, in which, for each retaining element 20, in projection in a plane formed by the upper face 12 of the base 10: - the lower end 34 of the rod 30 is inscribed in a first circle C1 with center 01, - the head 40 is inscribed in a second circle C2 with center 02 and diameter D2, said second circle C2 being the smallest circle comprising the head 40, which second circle C2 is typically tangent to one end of the head 40 in the longitudinal direction MD and / or the transverse direction CD, in which - the minimum distance between the respective edges of two first circles C1 of two lower ends 34 of adjacent rods 30 is at least greater than 50 micrometers, in particular greater than 70 microns, more particularly greater than 90 microns and / or less than 300 microns, less than 250 microns, more particularly less than 200 microns, and / or - in projection in a plane formed by the upper face 12 of the base 10, in a representative zone with retaining elements 20, the occupancy rate of the first circles C1 of the retaining elements 20 in said representative zone is between 25% and 80%, in particular between 40% and 80%, in particular between 50% and 70%.

[0082] By adjacent, we mean successive retaining elements along the same line formed by the retaining elements 20 on the upper face 12 of the base 10, or the closest retaining elements 20 belonging to two successive lines.

[0083] By representative area, we understand here an area comprising a plurality of elementary repeating patterns, for example between 5 and 10 patterns, typically 6 or 7 patterns. This area is typically observed from a photo obtained with a Keyence Corporation digital microscope under the reference “VHX 6000”, at X100 magnification and the measurements are obtained with the digital microscope’s image analysis software.

[0084] Thus, with such an arrangement, the space between the lower ends 34 of the rods 30 of the retaining elements 20 and / or the occupancy rate of the lower ends 34 of the rods 30 of the retaining elements 20 is sufficient to allow the base 10 to remain flexible while having peeling and shearing performances equivalent to those of prior products, or even improved in peeling due to the improved flexibility of the retaining device 1. Thus, the base 10 is sufficiently flexible to allow it to be wound into a roll for transport while having acceptable peeling and shearing performances, without consuming too much material. In addition, with such an occupancy rate, it is possible to obtain good flexibility of the retaining device 1, in particular when it is arranged for hygiene applications, for example for absorbent articles, in particular open or closed diapers.Previous products with a geometry such that the first circle C1 was included in the second circle C2 or in which only part of the second circle C2 was inscribed in the first circle C1 did not present such problems, but did present problems as mentioned in the preamble, in particular in terms of material consumption and user experience.

[0085] According to another example, the flexibility of the base 10 is improved with a base 10 whose thickness is between 10pm and 100pm, in particular between 15pm and 65pm, in particular between 16pm and 65pm, or between 22pm and 49pm.

[0086] In another example, the flexibility of base 10 is further improved for a base 10 with a grammage between 15 g / m 2 and 120g / m 2 , especially between 20 g / m 2 and 90g / m 2 , in some cases between 26g / m 2 and 70 g / m 2.

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

[0088] The non-woven material then has, for example, a weight of less than 80 g / m 2 , in some cases between 5 and 120 g / m 2 , between 10 and 70 g / m 2 .

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

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

[0091] Optionally, the number of retaining elements 20 per unit area is less than 600 retaining elements 20 per cm 2 and in particular is between 160 and 340 retaining elements 20 per cm 2 .

[0092] In the present application, the heights and thicknesses are typically observed from a photo obtained with a digital microscope from Keyence Corporation under the reference “VHX 6000”, at a magnification adapted, for example a magnification of X500 as is the case in Figure 2, and the measurements are obtained with the image analysis software of the digital microscope.

[0093] Generally speaking, it is possible to distinguish two types of self-gripping connections, those whose retaining elements cooperate with other retaining elements of the same types / natures or in the form of fibers and / or filaments and / or loops to produce mechanical connections and those whose retaining elements cooperate with surfaces to produce adhesive-type connections (Gecko) or using Van der Waals forces. Although this second type of connection can be considered in certain cases as a so-called self-gripping connection, such retaining elements using Van der Waals forces have a behavior and properties that are completely different from those using mechanical connections.Indeed, in the case of retaining elements using Van der Waal forces, only the upper faces of the heads ensure the attachment to the receiving surface, whereas in the case of retaining elements for mechanical attachment, the attachment is not ensured by the upper face of the heads but by the lower face of the head and the rod. According to one example, the device according to the invention is only suitable for making mechanical connections.

[0094] Although the present invention has been described with reference to specific exemplary embodiments, it is obvious 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, individual features of the various illustrated / mentioned embodiments may be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than restrictive sense.

[0095] It is also obvious that all the characteristics described with reference to a method are transposable, alone or in combination, to a device, in particular between the different aspects of the invention which are presented, and conversely, all the characteristics described with reference to a device are transposable, alone or in combination, to a process.

Claims

Demands

1. Restraint device (1) comprising: - a base (10) extending along a longitudinal direction (MD), having a top face (12) and a bottom face (14), - a plurality of retaining elements (20) extending over the upper face (12) of the base (10), each retaining element (20) comprising a rod (30) surmounted by 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, wherein, for each retaining element (20), in projection onto a plane formed by the upper face (12) of the base (10): - the lower end (34) of the rod (30) is inscribed in a first circle Cl of center 01,- the head (40) is inscribed in a second circle C2 of center 02 and diameter D2, said second circle being the smallest circle including the head, which second circle C2 being tangent to one end of the head (40) in the longitudinal direction (MD) and / or the transverse direction (CD), such that the maximum dimension of the head (40) passing through the center 02 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.

2. Retaining device (1) according to claim 1, wherein the second circle C2 is included in the first circle Cl.

3. Retaining device (1) according to any one of claims 1 or 2, wherein, the first circle Cl having a diameter Dl, the distance between 01 and 02 is less than or equal to 50% of the diameter Dl of the first circle Cl, in particular less than 30%, less than 25%, less than 20%, less than 15%, or less than 10%, and optionally, the distance between 01 and 02 is greater than or equal to 0% of the diameter Dl of the first circle Cl, or greater than 0%, or greater than 1%, or greater than 4%.

4. Retaining device (1) according to any one of claims 1 to 3, wherein the distance between 01 and 02 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 01 and 02 is greater than or equal to 0% of the diameter D2 of the second circle C2, or greater than 0%, or greater than 1%, or greater than 4%.

5. Retaining device (1) according to any one of claims 1 to 4, wherein the distance between 01 and 02 is less than or equal to 100pm, in particular less than or equal to 75pm, less than or equal to 50pm or less than or equal to 30pm.

6. Retaining 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, said circle C3 being contained in the second circle C2.

7. Retaining device (1) according to any one of claims 1 to 6, wherein a non-woven material (50) is attached to the underside (14) of the base (10).

8. Retaining device (1) according to any one of the preceding claims, wherein the ratio of the diameter D2 of circle C2 and the diameter DI of circle Cl is between 0.3 and 0.95 or more precisely between 0.5 and 0.

9.

9. Retaining device (1) according to any one of the preceding claims, wherein the retaining elements (20) have an attachment height (Ha) between 30 micrometers and 120 micrometers, more particularly between 30 micrometers and 70 micrometers, even more particularly between 40 micrometers and 60 micrometers.

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

11. Retaining device (1) according to any one of the preceding claims, wherein the rod (30) has a height (Ht) which is between 150 micrometers and 330 micrometers, in particular between 200 micrometers and 300 micrometers.

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

25.

13. Retaining device (1) according to any one of the preceding claims, wherein the ratio of the attachment 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.

14. Retaining device (1) according to any one of the preceding claims, wherein the rod (30) has, in side view along the longitudinal direction (MD) and / or the transverse direction (CD), a proximal portion extending from the lower end (34), a distal portion extending from the upper end (32) and an intermediate portion arranged between the proximal portion and the distal portion, the distal portion and the proximal portion having, with respect to a straight line perpendicular to the longitudinal direction (MD) and to the transverse direction (CD), a curvature greater than the curvature of the intermediate portion.

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

16. Retaining device (1) according to any one of the preceding claims, wherein, in side view along the longitudinal direction (MD) and / or the transverse direction (CD), said retaining device (1) has a ratio between the dimension of the upper end (32) of the rod (30) and the dimension of the lower end (34) of the rod (30) of 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.

Images