Improved holding device

Abstract

A holding device (1) comprises: a base (10) extending along a main direction (MD); a plurality of retaining elements (20) extending from the upper surface (12) of the base (10), the retaining elements (20) each having a stem (30) and a head (40), the stem (30) having a front end and a rear end in the main direction, characterized in that the head (40) of each retaining element (20) has two hooks (42) located on both sides of the stem (30) in the transverse direction (CD), the hooks (42) being arranged in the main direction (CD), and the hooks (42) being arranged in the main direction (CD). At least one of the hooks (42) has an inner recess (46) and a boundary (44) at least partially defining a contour of the inner recess (46).

Description

Technical Field

[0001] This invention relates to improved retaining devices, and more specifically, the object of this invention is for the production of retaining elements for hook and loop systems. Background Technology

[0002] Retention systems using hook-type retaining elements to produce hook-and-loop connectors are commonly used in many fields. However, the production of retaining elements has presented numerous challenges in both the design and manufacturing aspects, hindering the achievement of intended requirements.

[0003] Therefore, the object of the present invention is to at least partially solve some of these problems. Summary of the Invention

[0004] Therefore, the present invention provides a holding device, comprising: The base, extending along the main direction, has an upper surface and a lower surface, the upper surface forming a plane extending in a transverse direction along and perpendicular to the main direction. Multiple retaining elements extend from the upper surface of the base, each retaining element having a rod and a head, the rod having a front end and a rear end along the main direction. Its features are: Each retaining element has two hook portions on its head located on both sides of the rod in the lateral direction, each hook portion forming a radial protrusion relative to the rod. One of the hooks has a concavity and a boundary that at least partially defines the contour of the concavity.

[0005] According to one example, each hook has a concave surface and a boundary that at least partially defines the contour of the concave surface, the concave surfaces being disjoint.

[0006] According to one example, the concave portion has a curvature including at least one inflection point, and the straight line component perpendicular to the curvature and passing through said at least one inflection point has non-zero components along the transverse direction (CD) and / or along the principal direction (MD). Therefore, this concave shape of the hook increases its retention capability with a suitable mating element (e.g., a ring-type mating element), and this concave shape also allows for increased resistance when the hook is subjected to pressure using a suitable mating element (e.g., a ring-type mating element).

[0007] According to one example, the concave portion has a curved portion including at least two inflection points, and each straight component of the curved portion perpendicular to the concave portion and passing through the at least two inflection points has a non-zero component along the lateral direction (CD) and / or along the principal direction (MD). Therefore, this concave shape of the hook further increases the retention capability with a suitable mating element (e.g., a ring-type mating element), and the concave shape allows for a further increase in the resistance of the hook when subjected to pressure using a suitable mating element (e.g., a mating element with a ring).

[0008] According to one example, the concave portion has a curved section comprising at least a plurality of inflection points forming a bend that extends along a direction including a first component extending in a principal direction (MD) and a second component extending in a transverse direction (CD), the first and second components being non-zero. Therefore, this concave shape of the hook increases the retention capability with a suitable mating element (e.g., a ring-type mating element), and this concavity also allows for increased resistance when the hook is subjected to pressure using a suitable mating element (e.g., a mating element with a ring).

[0009] According to one example, the retaining element includes two hooks, each hook including a recess, the curves of each recess converging toward the front and / or rear of the retaining element. Thus, the retaining element has a preferred shape on one side for facilitating the insertion of a mating member (e.g., a mating member with a ring), and a preferred shape on the other side for retaining the mating member.

[0010] According to one example, the concave portion of the hook has a single rear edge or no rear edge along the main direction (MD), which may extend toward the front or rear of the retaining element. Therefore, this concave shape of the hook increases the retaining capacity with a suitable mating element (e.g., a ring-type mating element), and this concavity also allows for increased resistance when the hook is subjected to pressure using a suitable mating element (e.g., a mating element with a ring).

[0011] According to one example, the concave portion of the hook has no rear edge along the lateral direction (CD). Therefore, this concave shape of the hook increases the retention capability with a suitable mating part (e.g., a ring-type mating part), and this concavity also makes it possible to increase the resistance of the hook when subjected to pressure using a suitable mating part (e.g., a mating part with a ring).

[0012] According to one example, each hook has a recess and a boundary that at least partially defines the contour of the recess, the plurality of recesses joining from the front or rear of the retaining element.

[0013] According to one example, a recess is arranged on the lateral portion of the hook, particularly on the lateral portion of the hook that is at least partially oriented laterally and / or oriented toward the front or rear of the retaining element. Therefore, by utilizing the recessed arrangement of the hook, the retaining capacity with a suitable mating element (e.g., a ring-shaped mating element) is increased, and this recess also allows for an increase in the resistance of the hook when subjected to pressure using a suitable mating element (e.g., a ring-shaped mating element).

[0014] According to one example, the projection of the head onto the upper surface of the base lies between a front plane and a rear plane, the front plane being perpendicular to the principal direction and tangent to the front end of the rod, and the rear plane being perpendicular to the principal direction and tangent to the rear end of the rod. Therefore, with this arrangement of the head relative to the rod, the deformability of the head and / or rod is reduced when pressure is applied using a suitable mating element (e.g., a ring mating element), and the insertion capability of the mating element (e.g., a ring mating element) is improved. According to one example, one of the hooks has a concave shape, and the concave shape is non-through, or the cavity is typically a blind cavity. Therefore, with this concave shape, retention with a suitable mating element (e.g., a ring mating element) is stronger.

[0015] According to one example, each hook has a recess, and each recess is a non-through cavity, or each cavity is typically a blind cavity. Therefore, this recessed shape provides stronger retention with a suitable mating element (e.g., a ring mating element).

[0016] According to one example, a boundary section of the hook having a concave shape and at least partially defining the concave contour, arranged on the side opposite to the base and extending substantially in a plane parallel to the base, forms the boundary section of the hook most opposite to the base.

[0017] According to one example, each hook has a concave portion and a boundary that at least partially defines the contour of the concave portion. A boundary segment arranged on the side opposite to the base and extending substantially in a plane parallel to the base forms the boundary segment of the hook that is most opposite to the base.

[0018] In cases where each hook has a recess, the recesses are typically discontinuous or non-intersecting.

[0019] According to one example, the head has a central portion positioned in the lateral direction between two hooks, and the central portion has a maximum height in a direction perpendicular to the upper surface of the base, which is strictly less than the maximum height of the hooks.

[0020] According to one example, the central portion of the head has a front end and a rear end along the main direction, and the height of the central portion of the head relative to the upper surface of the base is strictly greater than the height of the rear end relative to the front end. Therefore, utilizing this height difference, the ability to insert a mating element (e.g., a mating element with a ring) is easier. According to one example, the rod has two lateral surfaces perpendicular to the lateral direction, each lateral surface being flat, and the two lateral surfaces being parallel or substantially parallel.

[0021] According to one example, each hook has an asperity defined on the surface opposite the concave portion. This asperity has the advantage of locally improving the retention of fibers or filaments with the ring-shaped mating element, particularly due to its location. Advantageously, the asperity is arranged on the surface of the hook opposite the concave portion and is arranged in a manner centered in the transverse direction (CD) relative to the retaining element and / or between the two lateral hooks.

[0022] According to one example, the rod has a rectangular cross-section, particularly a rectangular cross-section with right angles or rounded corners, which gradually narrows from the upper surface of the base toward the head.

[0023] According to one example, the rod has a square cross-section, particularly a square cross-section with right angles or rounded corners, which gradually narrows from the upper surface of the base toward the head.

[0024] According to one example, viewed parallel to the lateral direction (CD), the retaining element's rod has a front boundary and a rear boundary, each of which has a curved (non-linear) shape. More specifically, the portions of the front and rear boundaries arranged near the base are further apart than the portions arranged near half the height of the rod and / or near the head. Therefore, thanks to this shape, insertion of the mating element is facilitated; specifically, the mating element can be easily inserted and / or guided below the head.

[0025] According to one example, viewed parallel to the main direction (MD), the retaining element's rod has a left boundary and a right boundary, each of which has a substantially straight shape. More specifically, the arrangement of the left and right boundaries near the base is a straight line up to at least half the height of the rod.

[0026] According to one example, in a plane perpendicular to the main direction (MD) and passing through the concave, the concave has a curved portion defined between two endpoints, the curved portion having an arc, a C, or a U shape, and / or the second endpoint deviates from the plumbness passing through the first endpoint. Therefore, with this arrangement of the concave, the deformability of the head and / or rod is reduced when pressure is applied using a suitable mating element (e.g., a mating element with a ring), and the insertion capability of a suitable mating element (e.g., a mating element with a ring) is easier.

[0027] According to one example, in any plane perpendicular to the main direction (MD) and passing through the concave, the concave has a defined curved portion between two endpoints, the curved portion having an arc or a C or U shape respectively, and / or the second endpoint deviates from the vertical line passing through the first endpoint. Therefore, with this arrangement of the concave, the deformability of the head and / or rod is reduced when pressure is applied using a suitable mating element (e.g., a mating element with a ring), and the insertion capability of a suitable mating element (e.g., a mating element with a ring) is easier.

[0028] According to one example, in a plane perpendicular to the main direction (MD) and passing through the hook, the upper and lower edges of the hook define two endpoints, and the second endpoint of the hook is offset from the vertical line passing through the first endpoint of the hook. Therefore, with this concave arrangement, the deformability of the head and / or rod is reduced when pressure is applied using a suitable mating element (e.g., a mating element with a ring), and the insertion capability of a suitable mating element (e.g., a mating element with a ring) is easier.

[0029] According to one example, in any plane perpendicular to the main direction (MD) and passing through the hook (except for the end of the hook), the upper and lower edges of the hook define a first endpoint and a second endpoint respectively along the vertical direction, and the second endpoint of the hook is typically offset outward relative to the rod from the vertical line passing through the first endpoint of the hook. Therefore, utilizing this concave arrangement, the deformability of the head and / or rod is reduced when pressure is applied using a suitable mating element (e.g., a mating element with a ring), and the insertion capability of a suitable mating element (e.g., a mating element with a ring) is easier.

[0030] According to one example, when viewed perpendicularly to a plane including the main direction (MD) and the lateral direction (CD), the upper boundary of the head of the retaining element has a curved shape, preferably an arc or "C" shape, with its opening arranged at the front or rear of the retaining element. Therefore, this shape facilitates insertion and improves retaining capacity.

[0031] The present invention also relates to a method for forming a holding device, wherein: A base extending along a main direction is formed, the base having an upper surface and a lower surface, the upper surface forming a plane extending along the main direction and in a transverse direction perpendicular to the main direction, the base having a plurality of rods extending from its upper surface, each rod having a front end and a rear end along the main direction, the base being supported by a driving element that moves the base from upstream to downstream. A first forming step is performed, in which thermoforming is performed on the free end of the rod to drive material downstream from the free end of the rod, thereby forming a preform including a radial projection extending at least partially downstream from the free end of the rod. A second forming step is performed, in which the material for creating the preform is folded from downstream to upstream such that the downstream portion of the preform is folded over the central portion of the head. This forming step is performed to form two hooks located on both sides of the rod in the transverse direction, each forming a radial protrusion relative to the rod. At least one of the hooks has a concave shape and a boundary that at least partially forms / defines the concave contour.

[0032] According to one example, a forming step is performed such that each hook has a concave portion and a boundary that at least partially defines the contour of the concave portion, the concave portions being non-intersecting.

[0033] According to one example, a forming step is performed such that the projection of the head onto the upper surface of the base lies between a front plane and a rear plane, the front plane being perpendicular to the main direction and tangent to the front end of the rod, and the rear plane being perpendicular to the main direction and tangent to the rear end of the rod.

[0034] According to one example, the first forming step is performed by an element having a curved portion opposite to the curved portion of the base of the holding device, such as a roller, particularly a roller whose rotational speed and / or linear speed is greater than or equal to the driving speed of the driving element on the base (and / or in some cases strictly greater than the driving speed of the driving element on the base).

[0035] According to one example, the diameter of the forming roller in the first step is greater than or equal to 100 mm, particularly greater than or equal to 200 mm, and / or less than or equal to 1000 mm, particularly less than or equal to 450 mm.

[0036] According to one example, the second forming step is performed via a second forming station adapted to heat the preform.

[0037] According to one example, the second forming station includes rollers with a diameter greater than or equal to 100 mm, particularly greater than or equal to 200 mm, and / or less than or equal to 1000 mm, particularly less than or equal to 450 mm.

[0038] According to another example, the second forming station includes a convex element, such as a fixed convex element, which has the same curved portion as the curved portion of the base of the retaining device.

[0039] According to one example, the convex distance (minimum gap) of the convex element is greater than or equal to 0.20 mm, particularly greater than or equal to 0.30 mm, particularly greater than or equal to 0.40 mm, and / or less than or equal to 0.70 mm, particularly less than or equal to 0.60 mm.

[0040] According to a second aspect of the invention, independently and / or in conjunction with the remaining features of this specification, the invention relates to a holding device comprising: The base extends along the main direction and has an upper surface and a lower surface, the upper surface forming a plane that extends along the main direction and in a transverse direction perpendicular to the main direction; Multiple retaining elements extend from the upper surface of the base, each retaining element having a rod and a head, the rod having a front end and a rear end along the main direction. The head has a central portion positioned between two hooks in the lateral direction, and the maximum height of the central portion is strictly less than the maximum height of the hooks.

[0041] According to one example, for each retaining element, viewed in the lateral direction, the head extends along the main direction beyond the front and / or rear end of the rod, thus forming a front overhang and / or a rear overhang.

[0042] According to one example, the front and / or rear ends of the rod along the main direction are those front and / or rear ends of the rod arranged near the head, and / or those front and / or rear ends of the rod arranged near the base.

[0043] According to one example, for each retaining element, viewed in the lateral direction, the head has no front overhang but includes a rear overhang, or vice versa.

[0044] According to one example, the front and / or rear overhangs of the rod are greater than or equal to 2% of the rod size along the portion of the rod arranged near the head and / or through the portion of the rod arranged near the base, which is parallel to the main direction and passes through the rod. In particular, they are less than or equal to 20% of the rod size, and especially less than or equal to 15% of the rod size.

[0045] According to one example, for each retaining element, viewed in the lateral direction, the head has no front overhang and / or rear overhang.

[0046] According to one example, the head of the retaining element, and in particular each head of a plurality of retaining elements, is symmetrical along a plane passing through the center of the rod and perpendicular to the lateral direction CD.

[0047] According to one example, the head of the retaining element, and in particular each head of a plurality of retaining elements, is asymmetrical along a plane passing through the center of the rod and perpendicular to the principal direction MD.

[0048] According to one example, when viewed parallel to the main direction, the head forms at least one overhang that is greater than 10% of the width of the rod at the top, particularly greater than 15% of the width of the rod, particularly greater than 20% of the width of the rod, and more particularly greater than 40% of the width of the rod, and / or the head forms at least one overhang that is less than 90% of the width of the rod at the top, particularly less than 80% of the width of the rod, particularly less than 70% of the width of the rod.

[0049] According to one example, when viewed along the main direction, the head forms at least two overhangs, each overhang being greater than 10% of the width of the rod at the upper end, particularly greater than 15% of the width of the rod, particularly greater than 20% of the width of the rod, and even more particularly greater than 40% of the width of the rod, and / or the head forms at least one overhang, said overhang being less than 90% of the width of the rod at the upper end, particularly less than 80% of the width of the rod, and particularly less than 70% of the width of the rod.

[0050] According to one example, the head of each retaining element has two hooks, each hook forming a radial protrusion relative to the rod, particularly relative to the portion of the rod arranged near the head and / or relative to the portion of the rod arranged near the base.

[0051] According to one example, the hooks of the retaining element (in particular each hook) have an asymmetrical shape along any plane perpendicular to the main direction MD and / or along any plane perpendicular to the transverse direction CD.

[0052] According to one example, when viewed along the main direction, the head of the retaining element has two left and right end portions, the surfaces of which form an average angle greater than or equal to 30°, particularly greater than or equal to 40°, particularly greater than or equal to 45°, and / or less than or equal to 80°, particularly less than or equal to 75°, particularly less than or equal to 65°.

[0053] According to one example, this average is obtained from a series of at least 5 holding elements.

[0054] According to one example, when viewed along the main direction, particularly in the front view, the central portion of the head has two plate portions that are parallel to or substantially parallel to the upper surface of the base, the two plate portions being separated by, for example, dome-shaped and / or tip-shaped central protrusions.

[0055] According to one example, when viewed parallel to the main direction, the central part of the head has a central protrusion that is, for example, dome-shaped and / or pointed.

[0056] According to one example, viewed parallel to the main direction, the head of the element has a maximum size arranged at the hooks (multiple) along a direction perpendicular to the upper surface of the base, and a minimum size arranged between the hooks.

[0057] The average ratio of the maximum to the minimum head size is between 1% and 30%, specifically between 5% and 25%, and specifically between 7% and 22%. Using this ratio, the penetration of the retaining element (especially the head of the retaining element) into the ring is improved, while maintaining significant hooking ability.

[0058] According to one example, when viewed in a direction perpendicular to the upper surface of the base, the head has a general shape of an arc, a V, or a C, with its free ends arranged at the front or rear of the head.

[0059] According to one example, when viewed along the lateral direction CD, the head has a general shape of an arc, a V, or a C, with its free end positioned at the front or back of the head, or the head has a general teardrop shape, with its free end positioned at the front or back of the head.

[0060] According to one example, when viewed along the horizontal direction CD, the head has a front and a back, with the front being different from the back.

[0061] Based on one example, viewed along the transverse direction CD, the head has a front and a back. The front has a roughly rounded shape, while the back has a less rounded shape than the front, particularly a pointed shape, or vice versa.

[0062] According to one example, when viewed along the transverse direction CD, the concave has a general shape of an arc, V, or C, with its free end positioned at the front or back of the head; or the concave has a general teardrop shape, with its free end positioned at the front or back of the head; or the concave has a general square or rectangular shape, with its maximum rectangular length extending substantially parallel to the principal direction MD.

[0063] According to one example, when viewed along direction CD, the boundary has a general shape of an arc, V, or C, with its free ends positioned at the front or back of the head; or the boundary forms a profile with a general teardrop shape, with its free ends positioned at the front or back of the head; or the boundary forms a profile with a general square or rectangular shape, the maximum length of which extends substantially parallel to the main direction MD.

[0064] According to one example, when viewed along a direction perpendicular to the upper surface of the base, the head has an angle to the left and / or right to form an angle of attack between a straight line tangent to the hook and the lateral direction, which is on average greater than or equal to 15°, particularly greater than or equal to 17°, particularly greater than or equal to 20°, and / or less than or equal to 35°, particularly less than or equal to 32°, particularly less than or equal to 30°, and even more particularly less than or equal to 28°.

[0065] According to one example, when viewed along a direction perpendicular to the upper surface of the base, the angle formed between the two straight lines connecting the rear end of the head 40 and the front end of the hook along the main direction is greater than or equal to 60°, especially greater than or equal to 65°, especially greater than or equal to 70°, and / or less than or equal to 120°, especially less than or equal to 105°, especially less than or equal to 95°, and even more especially less than or equal to 28°.

[0066] According to one example, when viewed in a direction parallel to the lateral direction, the head has a cone-shaped section with its smallest opening facing the center of the head.

[0067] According to one example, one of the hooks forming a radial protrusion relative to the rod has a lower edge oriented toward the base and an upper edge opposite to the base. The projections of the lower and upper edges onto a plane parallel to the surface of the base have a continuous shape, such as a curved shape, particularly a general shape of C and / or U and / or V, with its opening oriented, for example, toward the rear end of the retaining element, more particularly a general shape of flattened C and / or flattened U and / or flattened V.

[0068] According to one example, one of the hooks forming a radial protrusion relative to the rod has a lower edge oriented toward the base and an upper edge opposite to the base. The projections of the lower and upper edges onto a plane perpendicular to the main direction have a continuous shape, such as a curved shape, particularly a general shape of C and / or U and / or V, with its opening oriented toward the center of the retaining element, more particularly a general shape of a flat C and / or flat U and / or flat V.

[0069] According to one example, one of the hooks forming a radial protrusion relative to the rod has a lower edge oriented toward the base and an upper edge opposite to the base. The projections of the lower and upper edges onto a plane perpendicular to the transverse direction have a continuous shape, such as a curved shape, particularly a general shape of C and / or U and / or V, with its opening oriented toward the rear of the retaining element, more particularly a general shape of a flat C and / or flat U and / or flat V.

[0070] According to one example, the base has continuous or substantially continuous ribs extending along the main direction on its upper surface. According to one example, one, two, three, or four ribs extend between two rows of retaining elements. In some cases, at least one rib extends to the foot of each retaining element.

[0071] According to one example, the retaining element has a height along a direction perpendicular to the longitudinal axis, which is greater than or equal to 200 micrometers, particularly greater than or equal to 250 micrometers, particularly greater than or equal to 300 micrometers, and / or less than or equal to 700 micrometers, particularly less than or equal to 600 micrometers, particularly less than or equal to 550 micrometers.

[0072] As an example, the retaining element and / or base are made of a thermoplastic-based material, such as: Polyolefins, particularly polypropylene (PP) and / or polyethylene (PE), especially bio-based polyethylene (Bio-PE) and / or copolymers thereof, and / or Polyesters, particularly polyethylene terephthalate (PET), such as bio-based polyethylene terephthalate (Bio-PET), and / or biodegradable polyesters and / or polyhydroxyalkanoates (PHA) and / or polylactic acid (PLA) and / or polybutylene terephthalate (PBAT) and / or polybutylene succinate (PBS) and / or poly(butylene succinate-co-butylene adipate) (PBS A) and / or poly(butylene succinate) (PES) and / or poly(trimethylene succinate) (PTS) and / or poly(butylene adipate-co-terephthalate) (PTAT) and / or polycaprolactone (PCL) and / or thermoplastic starch (TPS), and / or Polyamides (PAs), especially bio-based polyamides (Bio-PAs), and / or casein derivatives, and / or A mixture of two or more of these thermoplastic materials. Attached Figure Description

[0073] The invention and its advantages will be better understood after reading the following detailed description of various embodiments of the invention given by way of non-limiting examples.

[0074] [ Figure 1 ] Figure 1 This is a view of an example of a holding device according to one aspect of the present invention.

[0075] [ Figure 2 ] Figure 2 This is a three-dimensional diagram of an example of a retaining element.

[0076] [ Figure 3 ] Figure 3This is a view that holds an example of a component.

[0077] [ Figure 4 ] Figure 4 This is another view of an example of a retaining element.

[0078] [ Figure 5 ] Figure 5 This is another view of an example of a retaining element.

[0079] [ Figure 6 ] Figure 6 This is another view of an example of a retaining element.

[0080] [ Figure 7 ] Figure 7 This is a schematic diagram of a part of a device that can be used to produce such a retaining element.

[0081] In all the accompanying drawings, common elements are identified by the same reference numerals. Detailed Implementation

[0082] The following description is as follows Figure 1 An example of a holding device according to one aspect of the invention is shown, with a detailed partial view in... Figures 2 to 6 As shown in the example. Figures 1 to 6 The figures are drawn to scale, wherein the "spacing" (distance between two retaining elements) of the same column in the main direction MD is between 0.53 mm and 0.55 mm, preferably about 0.54 mm, and / or the height of the retaining elements is between 0.40 mm and 0.34 mm, preferably about 0.37 mm. Other characteristics, especially dimensional characteristics, can be directly derived from these figures.

[0083] In this disclosure, the measurements are typically obtained by averaging five measurements, which can be applied to five different holding elements.

[0084] The accompanying drawing shows a retaining device 1 including a base 10 and a plurality of retaining elements 20.

[0085] The base 10 forms a strip extending along the main direction MD or the machine direction. The base has an upper surface 12 and a lower surface 14, which are generally flat or substantially flat along a plane defined by the main direction MD and a transverse direction CD perpendicular to the main direction MD. The vertical direction is defined as the direction perpendicular to the plane defined by the main direction MD and the transverse direction CD in the direction from the lower surface 14 to the upper surface 12.

[0086] The thickness of the base 10 is defined as the distance between the upper surface 12 and the lower surface 14, which is usually the average distance between the upper surface 12 and the lower surface 14.

[0087] The retaining element 14 extends from the upper surface 12 of the base 10 and is generally formed as a single piece integrally made with the base 10.

[0088] The retaining element 14 typically has a height along a direction perpendicular to the upper surface 12 of the base 10, which is greater than or equal to 200 micrometers, particularly greater than or equal to 250 micrometers, particularly greater than or equal to 300 micrometers, and / or less than or equal to 700 micrometers, particularly less than or equal to 600 micrometers, particularly less than or equal to 550 micrometers.

[0089] According to one example, the retaining element 14 and / or the base 10 are made of a thermoplastic-based material, such as: Polyolefins, particularly polypropylene (PP) and / or polyethylene (PE), especially bio-based polyethylene (Bio-PE) and / or copolymers thereof, and / or Polyesters, particularly polyethylene terephthalate (PET), such as bio-based polyethylene terephthalate (Bio-PET), and / or biodegradable polyesters and / or polyhydroxyalkanoates (PHA) and / or polylactic acid (PLA) and / or polybutylene terephthalate (PBAT) and / or polybutylene succinate (PBS) and / or poly(butylene succinate-co-butylene adipate) (PBS A) and / or poly(butylene succinate) (PES) and / or poly(trimethylene succinate) (PTS) and / or poly(butylene adipate-co-terephthalate) (PTAT) and / or polycaprolactone (PCL) and / or thermoplastic starch (TPS), and / or Polyamides (PAs), especially bio-based polyamides (Bio-PAs), and / or casein derivatives; and / or A mixture of two or more of these thermoplastic materials.

[0090] In the example shown, the device has several rows of retaining elements 20, each extending along the main direction MD, so that the different rows are generally parallel to each other. This embodiment is not exhaustive; the retaining elements 20 can be arranged on the base 10 in any pattern and any configuration, particularly in an interlaced manner.

[0091] According to one example, the base 10 has continuous or substantially continuous ribs 16 extending along the main direction MD on its upper surface 12. According to one example, one, two, three, or four ribs extend between two rows of retaining elements 20. In some cases, at least one rib extends at the foot of each retaining element 20.

[0092] Each retaining element 20 has a rod 30 and a head 40.

[0093] The rod 30 extends from the upper surface 12 of the base 10 to the free end where the head 40 is located. The front and rear ends of the rod 30 are arbitrarily defined along the main direction MD. In the specification, the front and rear ends of various elements (particularly the retaining element 20 and the head 40 of the retaining element 20) may be referred to by the same arbitrary names. A front plane PA and a rear plane PR are defined perpendicular to the upper surface 12 of the base 10 and tangent to the front and rear ends of the rod 30, respectively.

[0094] In the example shown, rod 30 has a rectangular cross-section with rounded corners and gradually narrows from the upper surface 12 at the base to the free end of rod 30. In the example shown, rod 30 has two parallel lateral surfaces 32 and 34 that form the ends of rod 30 along the transverse direction CD.

[0095] In the example shown, rod 30 has a front surface 36 and a rear surface 38 along the main direction MD. The names front and rear are arbitrary and are mentioned here for illustrative purposes only.

[0096] In the example shown, the front surface 36 and the rear surface 38 tend to be closer together from the upper surface 12 of the base to the free end of the rod 30. Therefore, the thickness of the rod 30 along the principal direction MD generally narrows gradually from the upper surface 12 of the base to the free end of the rod 30. For a gradually narrowing cross-section, this means that the surface of the cross-section of the head 30 gradually narrows from the upper surface 12 of the base 10 toward the head 40. According to one example, the gradual narrowing can be continuous or discontinuous.

[0097] The head 40 is formed such that its cross-sectional dimensions are larger than those of the free end of the rod 30. Therefore, the head extends radially beyond the rod 30 to form a gripping area for a mating element, typically a ring or other retaining element.

[0098] In the example shown, the head 40 has two hooks 42, each forming a radial protrusion relative to the rod 30. As shown, the hooks 42 extend along the transverse direction CD on either side of the rod.

[0099] The hook portion 42 is typically formed such that, when projected along a plane parallel to the upper surface 12 of the base 10, it forms two parts inclined at an angle between 30° and 60° relative to the principal direction MD, and forms, for example, a V-shape or an arc, with its apex oriented towards the rear end along the principal direction MD. Angles A1 and A2 in Figure 6 The diagram is shown schematically.

[0100] Angle A1 represents the angle formed in the projection onto the upper surface 12 of the base 10 between the straight line tangent to the rearward inclined portion of each hook 42 and the transverse direction CD. This angle A1 is typically greater than or equal to 15°, particularly greater than or equal to 17°, particularly greater than or equal to 20°, and / or less than or equal to 35°, particularly less than or equal to 32°, particularly less than or equal to 30°, and even more particularly less than or equal to 28°. Therefore, by utilizing this angle, the mating member (e.g., a ring-type mating member) has a greater ability to slide from the rear region of the retaining element 14 to the front region of the retaining element 14.

[0101] Angle A2 represents the angle formed between two straight lines, each connecting the rear end and the front end of the head 40 when projected onto the upper surface 12 of the base 10 and considering the longitudinal direction. Angle A2 is typically greater than or equal to 60°, particularly greater than or equal to 35°, particularly greater than or equal to 70°, and / or less than 120°, particularly less than or equal to 105°, particularly less than or equal to 95°. Therefore, by utilizing this angle, the mating element (e.g., a ring-type mating element) has a greater ability to slide from the rear region of the retaining element toward the front region of the retaining element to facilitate retention.

[0102] According to one example, when viewed along the transverse direction CD, the head 40 has a general shape of an arc, V, C, or U, with its free end located at the front or rear of the head, or the head has a general teardrop shape, with its free end located at the front or rear of the head 40.

[0103] According to one example, viewed along the lateral direction CD, the head 40 has a front and a back, with the front being different from the back.

[0104] According to one example, viewed along the transverse direction CD, the head 40 has a front and a rear, the front having a generally rounded shape and the rear having a less rounded shape than the front, particularly a pointed shape, or vice versa.

[0105] At least one hook 42 (or typically each hook 42) has a boundary 44 forming the end of the hook 42 along the transverse direction CD. The boundary 44 at least partially forms a profile that is generally open and has two ends located at the same end or near the same front end or the same rear end of the head 40 (typically located at or near the rear end of the head 40). According to one example, a boundary segment 44 arranged on the side opposite to the base 10 and extending substantially in a plane parallel to the base 10 forms the boundary segment 44 of the hook 42 most opposite to the base 10.

[0106] According to one example, boundary 44 forms a profile with a C, U, or V shape, with its opening oriented, for example, toward the rear end of retaining element 20. In the accompanying drawings, the boundary is schematically shown by dashed lines.

[0107] According to one example, viewed along the transverse direction CD, the concave 46 has a generally arcuate, V-shaped, or C-shaped shape with its free end located at the front or rear of the head 40, or the concave 46 has a generally teardrop shape with its free end located at the front or rear of the head 40, or the concave 46 has a generally square or rectangular shape with its maximum rectangular length extending substantially parallel to the principal direction MD.

[0108] According to one example, viewed along direction CD, boundary 44 has a general shape of arc, V, C, or U, with its free ends arranged at the front or rear of head 40, or boundary 44 forms an outline with a general teardrop shape, with its free ends arranged at the front or rear of head 40, or boundary 44 forms an outline with a general square or rectangular shape, the maximum length of which extends substantially parallel to the main direction MD.

[0109] According to one example, a hook 42 forming a radial protrusion relative to the rod 30 has a lower edge oriented toward the base 10 and an upper edge opposite to the base 10. The projections of the lower and upper edges onto a plane parallel to the upper surface 12 of the base 10 have a continuous shape, such as a curved shape, particularly a general shape of C or U or U, with its opening oriented, for example, toward the rear end of the retaining element, more particularly a general shape of flat C and / or flat U and / or flat V.

[0110] According to one example, a hook 42 forming a radial protrusion relative to the rod 30 has a lower edge oriented toward the base 10 and an upper edge opposite to the base 10. The projections of the lower and upper edges onto a plane perpendicular to the principal direction MD have a continuous shape, such as a curved shape, particularly a general shape of C and / or U and / or V, with its opening oriented toward the center of the retaining element, more particularly a general shape of a flat C and / or flat U and / or flat V.

[0111] According to one example, a hook 42 forming a radial protrusion relative to the rod 30 has a lower edge oriented toward the base 10 and an upper edge opposite to the base 10. The projections of the lower and upper edges onto a plane perpendicular to the transverse direction CD have a continuous shape, such as a curved shape, particularly a general shape of C and / or U and / or V, with its opening oriented toward the rear of the retaining element, more particularly a general shape of flat C and / or flat U and / or flat V.

[0112] Boundary 44 can also form a closed profile.

[0113] For each hook 42, a boundary 44 is typically formed on the portion forming an inclined surface oriented along a direction having components along the main direction MD, the transverse direction CD, and the non-zero vertical direction.

[0114] Figure 5 Angle A3 is schematically shown when viewed in a plane perpendicular to the principal direction MD. It represents the angle formed between a straight line tangent to the inclined surface of the hook 42 and the transverse direction CD. This angle A3 is typically greater than 30°, particularly greater than or equal to 40°, particularly greater than or equal to 45°, and / or less than or equal to 80°, particularly less than or equal to 75°, particularly less than or equal to 65°.

[0115] Boundary 44 surrounds the recessed portion or indentation 46 formed in the inclined surface of each hook 42. Angle A3 specifically defines the orientation of the indentation 46 along the normal direction of the plane defined by a straight line tangent to the inclined surface of the hook 42, including the indentation 46. In the example shown, it can be seen that the indentation 46 is oriented along a direction having a non-zero component in the vertical direction and a non-zero component in the transverse direction. In other words, the indentation 46 is oriented at least partially upward, that is, it is oriented along a direction opposite to that of the base 10.

[0116] The recess 46 is typically a non-through or blind recess. Thus, in the case where each hook 42 includes a recess, the two recesses 46 do not intersect and are specifically separated by a central portion 50, which will be described later.

[0117] The concave portion 46 typically has a curved portion including at least one inflection point, and the straight component perpendicular to the curved portion and passing through said at least one inflection point has a non-zero component in the transverse direction (CD) and / or in the principal direction (MD). Therefore, this concave shape of the hook increases the retention capability with a suitable mating element (e.g., a ring-type mating element), and this concavity allows for increased resistance when the hook is subjected to pressure using a suitable mating element (e.g., a ring-type mating element).

[0118] As a variation, the concave portion typically has a curved section comprising at least two inflection points. Each straight component of the curved section perpendicular to the concave portion and passing through the at least two inflection points has a non-zero component along the transverse direction (CD) and / or along the principal direction (MD). Therefore, this concave shape of the hook further increases the retention capability with a suitable mating element (e.g., a ring-type mating element), and the concave shape further enables an increase in the resistance of the hook when subjected to pressure using a suitable mating element (e.g., a mating element with a ring).

[0119] As a variation, the concave 46 has a curved portion that includes at least a plurality of inflection points forming a bend line that extends along a direction including a first component extending along the principal direction (MD) and a second component extending along the transverse direction (CD), the first and second components being non-zero. Figure 6 The diagram schematically illustrates the bend 47 for the two shown recesses 46. Therefore, this concave shape of the hook increases its retention capability with a suitable mating element (e.g., a ring-type mating element), and this concavity also allows for increased resistance when the hook is subjected to pressure using a suitable mating element (e.g., a mating element with a ring).

[0120] According to one example, the retaining element 20 includes two hooks, each hook including a recess 46, the bends of which converge toward the front and / or rear of the retaining element. Thus, the retaining element 20 has a preferred shape on one side that facilitates the insertion of a mating member (e.g., a mating member with a ring), and a preferred shape on the other side that retains the mating member.

[0121] According to one example, the recess 46 of the hook has a single rear edge or no rear edge in the main direction (MD), which may extend toward the front or rear of the retaining element 20. Thus, this concave shape of the hook increases the retaining capacity with a suitable mating element (e.g., a ring-type mating element), and this concavity also makes it possible to increase the resistance of the hook when subjected to pressure using a suitable mating element (e.g., a mating element with a ring).

[0122] According to one example, the concave portion 46 of the hook has no rear edge in the lateral direction (CD). Therefore, this concave shape of the hook increases the retention capability with a suitable mating part (e.g., a ring-type mating part), and this concavity also makes it possible to increase the resistance of the hook when subjected to pressure using a suitable mating part (e.g., a mating part with a ring).

[0123] According to one example, a recess 46 is arranged on the lateral portion of the hook, particularly on the lateral portion of the hook that is at least partially oriented laterally and / or toward the front or rear of the retaining element. Therefore, the recessed arrangement 46 of the hook increases the retaining capacity with a suitable mating element (e.g., a ring-shaped mating element), and this recess also allows for increased resistance when the hook is subjected to pressure using a suitable mating element (e.g., a ring-shaped mating element).

[0124] The head 40 has a central portion 50 located in the extension of the rod 30 and between the hook portions 42. The central portion 50 has a front end and a rear end along the main direction MD.

[0125] In the example shown, the height at the rear end of the central portion 50 is strictly greater than the height at the front end of the central portion 50, which is measured relative to the upper surface 12 of the base 10.

[0126] According to one example, considering a view in a plane perpendicular to the main direction MD, the head 40 has a maximum and a minimum dimension measured along the height direction perpendicular to the upper surface 12 of the base 10. The maximum dimension is typically located at the hook 42. The minimum dimension is typically located between the hooks 42, in the central portion 50 of the head 40. The average ratio of this maximum dimension to this minimum dimension of the head 40 is typically greater than or equal to 1%, particularly greater than or equal to 5%, particularly greater than or equal to 7%, and / or less than or equal to 30%, particularly less than or equal to 25%, particularly less than or equal to 22%. Utilizing this ratio, penetration of the retaining element (particularly the head 40 of the retaining element) into the ring is improved, while maintaining significant hooking capability.

[0127] The rear end of the central portion 50 of the head 40 may typically have a protrusion 52 that is oriented rearward along the main direction MD and typically oriented upward along the height.

[0128] The maximum height of the central portion 50 of the head 40 is usually less than the maximum height of the hook 42.

[0129] The central portion 50 of the head 40 typically has a recess or indentation in the extension of the rod 30, which may be generated, for example, by the displacement of material after a separate second forming step and / or after consecutive first and second forming steps, or by the removal or shrinkage of material after the holding element 20 is formed.

[0130] The engagement between the hook portion 42 and the central portion 50 of the head 40 typically forms a rough portion 48 on a surface of each hook portion 42 opposite to the recess 46. The rough portion 48 is typically sized to allow the passage of a ring or filament of the mating element, thereby allowing engagement between the retaining element 40 and the ring or filament. The rough portion 48 shown is formed between each hook portion 42 and the central portion 50 of the head 40.

[0131] According to one example, the head 40 is formed such that the projection of the head 40 onto the upper surface 12 of the base 10 lies between the front plane PA and the rear plane PR. This configuration of the head relative to the rod allows for a reduction in the deformability of the head and / or the rod when subjected to pressure using a suitable mating member (e.g., a mating member of a ring), and thus improves the insertion capability of the mating member (e.g., a mating member of a ring).

[0132] According to such Figure 1Another example shown on other retaining elements, viewed along the main direction, particularly in a forward-oriented manner, is that the central portion of the head 40 has two plate portions parallel to or substantially parallel to the upper surface of the base, the two plate portions being separated by, for example, dome-shaped and / or tip-shaped central protrusions.

[0133] According to one example, for each retaining element 14, viewed along the lateral direction CD, the head 40 extends along the main direction MD beyond the front end and / or rear end of the rod 30, thereby forming a front overhang and / or a rear overhang.

[0134] According to one example, the front and / or rear ends of the rod 30 along the main direction MD are those front and / or rear ends of the rod 30 arranged in the portion near the head 40 and / or the portion of the rod 30 arranged in the portion near the base 10.

[0135] According to one example, for each retaining element 14, viewed in the lateral direction, the head 40 has no front overhang but includes a rear overhang, or vice versa.

[0136] According to one example, the front overhang and / or rear overhang are greater than or equal to 2% of the size of the rod 30 along the direction parallel to the main direction MD and passing through the portion of the rod 30 arranged near the head 40 and / or passing through the portion of the rod 30 arranged near the base 10, and / or less than or equal to 20% of that size, particularly less than or equal to 15% of that size.

[0137] According to one example, for each retaining element 14, viewed along the lateral direction CD, the head 40 has no front overhang and / or rear overhang.

[0138] According to one example, when viewed parallel to the main direction MD, the head 40 forms at least one overhang that is 10% greater than the width of the rod 30 at the upper end, particularly 15% greater than the width, particularly 20% greater than the width, and more particularly 40% greater than the width, and / or the head 40 forms at least one overhang that is less than 90% greater than the width of the rod 30 at the upper end, particularly 80% greater than the width, and more particularly 70% greater than the width.

[0139] According to one example, viewed along the main direction, the head 40 forms at least two overhangs, each overhang being equal to or greater than 10% of the width of the rod 30 at its upper end, particularly equal to or greater than 15% of that width, particularly equal to or greater than 20% of that width, and more particularly equal to or greater than 40% of that width, and / or the head 40 forms at least one overhang, said at least one overhang being equal to or less than 90% of the width of the rod 30 at its upper end, particularly equal to or less than 80% of that width, and particularly equal to or less than 70% of that width.

[0140] Subsequently, referring to Figure 7 An example of equipment used to produce such retaining elements is shown.

[0141] The accompanying drawing shows a portion of the apparatus used to form the holding device. The displacement or rotation of the various components is indicated by arrows.

[0142] The illustrated device portion focuses on the formation of the head 40 of the retaining element 20. Here, consider the base 10 from which the rod 30 extends, already formed upstream. The following references to upstream and downstream are made relative to the direction of product displacement on the device.

[0143] As shown, the base 10 is formed by a rod 30, but typically does not have a head for retaining the element 20. The rod 30 may also be covered by a precursor or preform for the head. The base 10 is driven by a drive element 72 (such as a roller).

[0144] The first forming station 74 (typically including forming rollers) performs thermoforming operations on the free end of the lever 30, or, where applicable, thermoforming operations on a preform or precursor. This thermoforming operation is typically performed at a rotational and / or linear speed greater than or equal to, or in some cases strictly greater than, the drive speed of the drive element 72 on the strip 10. The first forming station 74 typically includes forming rollers that are rotationally driven in a manner that tends to move material downstream from the free end of the lever 30, or, where applicable, from the free end of the preform or precursor.

[0145] This forming step typically creates a flat or substantially flat head preform 40 that extends radially relative to the free end of the rod 30 and extends at least partially downstream.

[0146] Subsequently, the second forming station 76 is positioned downstream of the first forming station 74.

[0147] The second forming station 76 is configured to fold or convex the head preform produced by the first forming station 74. More specifically, the second forming station 76 is configured to fold the preform itself from downstream to upstream. Thus, the downstream portion of the head preform will fold back at least partially onto the central portion of the head. This material folding effect will specifically form two hooks 42 and will define the profile formed by the boundary 44, as described above.

[0148] The second forming station 76 may, for example, include a second forming roller that is driven to rotate in the opposite direction to the product's displacement direction. The second forming station 76 typically raises the temperature of the preform at the head 40 to allow or facilitate folding of the material.

[0149] The second forming station 76 is arranged to apply a temperature greater than or equal to the thermal deflection temperature (HDT) of the material used, for example, applying a temperature 5°C greater than the HDT, or 10°C greater than the HDT, particularly 20°C greater, particularly 25°C greater, and even more particularly 30°C greater, and / or less than the HDT corresponding to +70°C, particularly less than the HDT corresponding to +60°C, particularly less than the HDT corresponding to +55°C, even more particularly less than the HDT corresponding to +50°C, or even more particularly less than the HDT corresponding to +40°C. The second forming station 76 is also arranged to apply a temperature lower than the melting temperature of the material used, particularly applying a temperature 10°C lower than the melting temperature of the material used. These temperatures are typically used for speeds greater than 5 m / min and less than 130 m / min, and in some cases less than 25 m / min. Therefore, the material folds itself without being fully heated and softened to the point of becoming fluid. Consequently, processability is better controlled, the energy required to produce the retaining element (especially the energy required to heat the retaining element) is lower, and the manufacturing speed of such retaining elements is increased.

[0150] Compared to conventional retaining devices, the proposed device has improved properties. Specifically, the proposed retaining element 20 allows for a denser arrangement, less wear, and a less rough product. Furthermore, the structure of the head 40 allows for improved engagement of mating parts (such as rings or fibers) and improves the mechanical strength of the head 40, which in turn improves the performance and robustness of the product.

[0151] According to one example, the number of retaining elements 20 is between 50 and 450 per square centimeter, particularly between 50 and 170 per square centimeter, or in other cases between 200 and 350 per square centimeter.

[0152] According to one example, the assembly formed by the base 10 and the plurality of retaining elements 20 typically has a base weight greater than or equal to 45 g / m², particularly greater than or equal to 70 g / m², and / or less than or equal to 250 g / m².

[0153] According to one example, the base 10 has a thickness along a direction perpendicular to the surface of the bearing retaining element, the thickness being greater than 30 micrometers, particularly greater than or equal to 50 micrometers, and / or less than or equal to 200 micrometers, particularly less than or equal to 150 micrometers.

[0154] According to one example, considering the portion of base 10 equipped with retaining element 14, and therefore disregarding any areas of base 10 without retaining elements, the projection of retaining element 14 onto the outer surface of base 10 covers at least 5% of the outer surface of base 10, specifically at least 7%, specifically at least 10%, more specifically at least 15%, preferably at least 17%, and / or at most 45%, specifically at most 40%, specifically at most 35%. Generally, for objects preceded by the words "for each" or "each of them," it should be understood that a large portion of these objects according to the invention, such as at least 50%, 60%, 70%, 80%, 90%, or 100%, includes the stated characteristics.

[0155] Although the invention has been described with reference to specific exemplary embodiments, it will be 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. Specifically, individual features of the different embodiments shown / mentioned may be combined in other embodiments. Therefore, the description and drawings should be considered in an illustrative rather than restrictive sense.

[0156] It is also evident that all the features described with reference to a method can be applied individually or in combination to a device, and conversely, all the features described with reference to a device can be applied individually or in combination to a method.

Claims

1. A holding device (1), comprising: The base (10) extends along the main direction (MD) and has an upper surface (12) and a lower surface (14), the upper surface (12) forming a plane extending along the main direction (MD) and in a transverse direction (CD) perpendicular to the main direction (MD). Multiple retaining elements (20) extend from the upper surface (12) of the base (10), each retaining element (20) having a rod (30) and a head (40), the rod (30) having a front end and a rear end along the main direction (MD). Its features are: The head (40) of each retaining element (20) has two hooks (42) located on both sides of the rod (30) along the lateral direction (CD), each hook forming a radial protrusion relative to the rod (30). At least one of the hooks (42) has a concave (46) and a boundary (44) that at least partially defines the contour of the concave (46).

2. The holding device (1) according to claim 1, wherein, Each hook (42) has a recess (46) and a boundary (44) that at least partially defines the contour of the recess (46), the recesses (46) being non-intersecting.

3. The holding device (1) according to claim 2, wherein, The concave portion (46) has a curved portion including at least one inflection point, such that the straight component perpendicular to the curved portion of the concave portion and passing through the at least one inflection point has a non-zero component along the transverse direction (CD) and / or along the principal direction (MD).

4. The retaining device (1) according to any one of claims 2 or 3, wherein, The recess (46) is arranged on the lateral portion of the hook (42), particularly on the lateral portion of the hook that is at least partially oriented laterally and / or oriented toward the front or rear of the retaining element (1).

5. The retaining device (1) according to any one of claims 1 to 4, wherein, In any plane perpendicular to the main direction (MD) and passing through the hook (42), the upper and lower edges of the hook (42) define a first endpoint and a second endpoint respectively along a vertical direction perpendicular to the base (10), and the second endpoint of the hook (42) is offset outward relative to the rod (30) from the vertical line passing through the first endpoint of the hook.

6. The retaining device (1) according to any one of claims 1 to 5, wherein, The projection of the head (40) onto the upper surface (12) of the base (10) is between the front plane and the rear plane, the front plane being perpendicular to the main direction (MD) and tangent to the front end of the rod (30), and the rear plane being perpendicular to the main direction (MD) and tangent to the rear end of the rod (30).

7. The holding device (1) according to any one of claims 1 to 6, wherein, The head (40) has a central portion (50) positioned between the two hooks (42) along the lateral direction (CD), the maximum height of the central portion (50) along the direction perpendicular to the upper surface (12) of the base (10) being strictly less than the maximum height of the hooks (42).

8. The holding device (1) according to claim 7, wherein, The central portion (50) of the head (40) has a front end and a rear end along the main direction, and wherein the central portion (50) of the head has a rear end and a front end such that the height at the rear end is strictly greater than the height at the front end, the height being measured relative to the upper surface (12) of the base (10).

9. The holding device (1) according to any one of the preceding claims, wherein, The rod (30) has two lateral surfaces (32, 34), each of which is flat and the two lateral surfaces (32, 34) are parallel and extend in a direction parallel to the main direction (MD) or parallel to the transverse direction (CD).

10. The holding device (1) according to any one of the preceding claims, wherein, Each hook (42) defines a rough portion (48) on the surface of the hook opposite to the concave portion (46).

11. The holding device (1) according to any one of the preceding claims, wherein, The rod (30) has a rectangular or square cross section, particularly a rectangular or square cross section with right angles or rounded corners, which gradually narrows from the upper surface (12) of the base (10) toward the head (40).

12. A method for forming a holding device (1), wherein: A base (10) is formed extending along a main direction (MD), the base having an upper surface (12) and a lower surface (14), the upper surface (12) forming a plane extending along the main direction (MD) and a transverse direction (CD) perpendicular to the main direction (MD), the base (10) having a plurality of rods (30) extending from its upper surface (12), each rod (30) having a front end and a rear end along the main direction (MD), the base (10) being supported by a drive element (72) that moves the base from upstream to downstream. A first forming step is performed, in which thermoforming is performed on the free end of the rod (30) to drive material downstream from the free end of the rod (30) to form a preform comprising a radially extending, at least partially, radially extending downstream from the free end of the rod (30). A second forming step is performed, in which a folding of the material of the preform is created from downstream to upstream, such that the downstream portion of the preform is folded over the central portion (50) of the head (30). The forming step is performed to form a head (40) at the free end of the rod (30), the head including two hooks (42) located on both sides of the rod (30) along the transverse direction (CD), each hook forming a radial protrusion relative to the rod (30), at least one of the hooks (42) having a concave (46) and a boundary (44) that at least partially defines the contour of the concave (46).

13. The method according to claim 12, wherein, The forming step is performed such that each hook (42) has a concave (46) and a boundary (44) that at least partially defines the contour of the concave (46), the concave (46) being non-intersecting.

14. The method according to any one of claims 12 or 13, wherein, The forming step is performed such that the projection of the head (40) on the upper surface (12) of the base (10) is between the front plane and the rear plane, the front plane being perpendicular to the main direction (MD) and tangent to the front end of the rod (30), and the rear plane being perpendicular to the main direction (MD) and tangent to the rear end of the rod (30).

15. The method according to any one of claims 12 to 14, wherein, The first forming step is performed by a roller (74) whose rotational speed and / or linear speed is greater than or equal to the driving speed of the driving element (72) on the base (10), and wherein the second forming step is performed by a second forming station adapted to perform heating of the preform.

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