CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. national phase entry under 35 U.S.C. § 371 of International Application No. PCT/FR2017/051012, filed on Apr. 28, 2017, which claims priority to French Patent Application No. 1653866, filed on Apr. 29, 2016; French Patent Application No. 1653870, filed Apr. 29, 2016; French Patent Application No. 1653872, filed Apr. 29, 2016; French Patent Application No. 1653873, filed Apr. 29, 2016; French Patent Application No. 1653888, filed Apr. 29, 2016; French Patent Application No. 1653894, filed Apr. 29, 2016; and French Patent Application No. 1653897, filed Apr. 29, 2016; the entireties of each of which are herein incorporated by reference.

GENERAL TECHNICAL FIELD

The present disclosure relates to the field of closure systems, and more particularly it relates to closure systems with hooks and to associated methods and apparatuses for fabricating them.

STATE OF THE PRIOR ART

Conventional methods and apparatus for making closure systems comprising self-gripping elements such as hooks conventionally use means for extruding plastics material in a continuous profile and then cutting it and deforming it in the longitudinal direction in order to form the hooks.

Those successive steps would require in particular a plurality of heating and cooling steps during the method, which leads to complexification and to a consequent increase in the dimensions of the apparatus needed for manufacturing.

In addition, each cooling step contributes to increasing the occupation time of the device, which is penalizing. Furthermore, the need to cool the material between the various steps of the method and therefore between the various workstations of the installation leads to the production line being slowed down.

In addition, the workstations and cutting steps consequently lead to an increase in the dimensions of the apparatus, thereby making it very complex to install.

Furthermore, the various manufacturing methods are commonly limited in terms of the shape of the retaining elements, the shape of the retaining elements for example being determined by structural elements of the apparatus associated therewith that cannot be modified easily by the user without requiring consequent modification of the apparatus.

The present disclosure thus seeks to address these various problems.

SUMMARY OF THE DISCLOSURE

First Aspect of the Disclosure

In a first aspect, the present disclosure relates to a retaining device comprising:a base extending in a longitudinal direction and presenting a top face and a bottom face;a plurality of retaining elements extending from the top face of the base, each of the retaining elements being formed by a stem surmounted by a head, the stem having a bottom end connected to the base, and a top end opposite from the bottom end, the head surmounting the top end of the stem, and having a bottom face facing towards the base and a top face opposite from the bottom face;

the device being characterized in thatthe base presents a thickness lying in the range 10 micrometers (μm) to 700 μm, where the thickness is the distance between the top face and the bottom face; andthe top face of the head of each retaining element includes a rib.

In an example, the head of each retaining element includes a catch portion extending radially relative to the top end of the stem, said rib extending at least in part over the catch portion.

In an example, the head of each retaining element includes two catch portions extending radially relative to the top end of the stem, each of said catch portions including a rib, said catch portions extending on either side of the stem.

The head may then include a rib extending continuously between the two catch portions.

In an example, the head further includes a transverse rib extending between two opposite ends of the head on either side of an axis extending in the longitudinal direction and passing via the stem and/or the head, typically via the middle of the stem and/or of the head, the transverse rib extending over the top end of the stem.

In an example, the at least one catch portion includes a downwardly sloping free end.

In an example, the top face of the head of each retaining element as two distinct rims extending at least in part over the same catch portion.

In an example, for each retaining element, each of the ribs extends over a fraction only of the periphery of the head, in particular the combined length of the ribs of a retaining element under consideration lies in the range 5% to 95% of the length of the periphery of the head of the retaining element under consideration, more particularly in the range 30% to 85% of the length of the periphery of the head of the retaining element under consideration.

In an example, said base has two edges in the longitudinal direction, and wherein each of said edges presents highs and lows, the maximum offset between the highs and the lows along a direction transverse to the longitudinal direction being less than 1 millimeter (mm) over a length in the longitudinal direction that corresponds to three consecutive highs.

In an example, the width of the base lies in the range 1 mm to 500 mm, more particularly in the range 3 mm to 100 mm.

In an example, the retaining elements have a height lying in the range 5 μm to 5000 μm, or indeed in the range 5 μm to 2000 μm, or more particularly in the range 20 μm to 800 μm, with height being measured in a direction perpendicular to the top face of the base.

In an example, the stem of each retaining element presents symmetry of rotation about an axis perpendicular to the top face of the base.

In an example, each rib of the head extends in a direction that is substantially transverse (i.e. to within ±30°) to said longitudinal direction of the base.

In an example, the retaining elements present a shape that is asymmetrical relative to a plane that is transverse to the longitudinal direction of the base.

In an example, each retaining element presents symmetry relative to a plane extending in a longitudinal direction of the base and containing the axis of the stem of the retaining element. This rib is arranged in such a manner as to reinforce of the head of the hook, in particular its catch portions, in order to facilitate inserting and/or passing fibers or filaments under the head so as to enable them to be retained. The height of the rib (measured along a direction perpendicular to the plane of the base) lies typically in the range 0.005 mm to 0.1 mm, preferably in the range 0.01 mm to 0.08 mm. The term “rib” designates a longitudinal portion that extends, in its height direction, from the surface of the head substantially away from the base. This represents a length (measured substantially along the longitudinal direction) that is greater than its width (measured substantially along a transverse direction). More particularly, the ratio of the width over the length of the rib is strictly less than 1. In other words, the rib forms a projection from the top surface of the hook in such a manner that the top surface of the hook is not flat.

In an example, each catch portion extends in a direction that is substantially perpendicular to the longitudinal direction of the base.

In an example, each rib, seen from above the hook, presents a V-shape in which the angle between the two branches of the upside down V-shape (or U-shape or C-shape) lies in the range 90° to 180°, more particularly in the range 110° to 170°, or more precisely in the range 140° to 150°. The tip of the upside down V-shape is typically situated towards the front of the hook in the longitudinal direction.

In an example, the length of at least one rib in a direction transverse to the longitudinal direction of the base is greater than the diameter of the stem in a direction perpendicular to the longitudinal direction of the base.

Second Aspect of the Disclosure

In a second aspect, the present disclosure relates to a retaining device with hooks comprisinga base extending in a longitudinal direction and presenting a top face and a bottom face;a plurality of retaining elements extending from the top face of the base, each retaining element being formed by a stem and a head;

the device being characterized in that:the base presents a thickness lying in the range 10 μm to 700 μm, where the thickness is the distance between the top face and the bottom face; andthe base has two edges in the longitudinal direction, each of said edges presents highs and lows, wherein the maximum offset between the highs and the lows along a direction transverse to the longitudinal direction is less than 1.0 mm over a length in the longitudinal direction that corresponds to three consecutive highs.

In an example, in section view on a direction transverse to the longitudinal direction, said edges present portions of rounded shape.

In an example, the maximum offset between the highs and the lows in a direction transverse to the longitudinal direction and over a length in the longitudinal direction corresponding to three successive highs, said maximum offset lies in the range 0.001 mm to 1.0 mm, more particularly the range 0.001 mm to 0.5 mm, still more particularly in the range 0.001 mm to 0.1 mm.

In an example, the three consecutive highs are over a distance that is less than the distance corresponding to 15 times the hook pitch, preferably less than a distance of 25.0 mm.

In an example, the width of the base measured in a direction transverse to the longitudinal direction lies in the range 1 mm to 500 mm, more particularly in the range 3 mm to 100 mm.

In an example, the retaining elements have a height lying in the range 5 μm to 5000 μm, or indeed in the range 5 μm to 2000 μm, or more particularly in the range 20 μm to 800 μm, or still more particularly in the range 100 μm to 500 μm, with height being measured in a direction perpendicular to the top face of the base.

In an example, the stem of each retaining element presents symmetry of rotation about an axis perpendicular to the top face of the base.

In an example, each of the retaining elements is formed by a stem surmounted by a head, the stem having a bottom end connected to the base, and a top end opposite from the bottom end, the head surmounting the top end of the stem, and having a bottom face facing towards the base and a top face opposite from the bottom face, and wherein the top face of the head of each retaining element includes a rib.

In an example, the retaining elements present a shape that is asymmetrical relative to a direction that is transverse to the longitudinal direction of the base.

In an example, each retaining element presents symmetry relative to a plane extending in a longitudinal direction of the base and containing the axis of the stem of the retaining element. The base of the tape is thus free from any extra thickness extending continuously along its edges, and typically presents a thickness that is substantially constant from one edge to the other. A thickness is said to be “substantially” constant when that thickness presents variation of less than 15%. More generally, it can be understood that the base of the tape may be free from any non-functional extra thickness (or from any extra thickness having the sole function of improving the regularity of the margins of the tape), which is advantageous in production terms in so far as extra thickness leads to overconsumption of material and increases the length of time the molds are occupied.

In an example, the device further comprises a layer of nonwoven material secured to the bottom face of the base and/or to the top face of the base, and wherein fractions of fibers and/or filaments of the layer of nonwoven material are encapsulated in the base.

In an example, the device further comprises a plastics film or an elastic film or a composite film secured to the bottom face of the base, the surface area of the film in contact with the bottom face of the base being greater than the projection of the surface area of the film onto a plane defined by the bottom face of the base.

Third Aspect of the Disclosure

In a third aspect, the present disclosure relates to a method of assembling an assembly comprising a tape of retaining elements and a substrate, said method comprising the following steps:a step of forming a tape of retaining elements by dispensing a molding material into a molding device, so as to form a tape of retaining elements comprising a base presenting a bottom face and a top face, the top face of the base being provided with retaining elements; anda step of applying a substrate against the bottom face of the base prior to said bottom face of the base solidifying in such a manner as to cause the substrate to penetrate at least in part beyond a plane defined by the bottom face of the base of the tape.

In an example, during the step of applying a substrate against the bottom face of the base, the bottom face of the base, upstream from the application step, is at a temperature that is lower than its melting temperature, or more particularly lower than the heat deflection temperature of the material forming the base, and the temperature of the base results solely from the step of forming the tape.

In an example, during the step of applying the substrate against the bottom face of the base, the base is at a surface temperature lying between the melting temperature of the material constituting the base and the Vicat B softening temperature of the material constituting the base minus 30° C., more particularly between the melting temperature of the material constituting the base and the Vicat A softening temperature of the material constituting the base, or indeed in the range 75° C. to 150° C., in particular substantially equal to 105° C. for a base made of polypropylene.

In an example, during the step of applying the substrate against the bottom face of the base, pressure is applied by means of a roller.

In an example, the method includes a subsequent step of unmolding the assembly formed by the tape of retaining elements and the substrate.

In an example, the substrate is a layer of nonwoven material, and wherein portions of fibers and/or filaments of the layer of nonwoven material are encapsulated in the base.

The step of applying the substrate against the bottom face of the base prior to solidification of said bottom face of the base is then typically performed in such a manner as to cause portions of fibers and/or filaments of the nonwoven layer to penetrate into the base, at least in part.

In a variant, the substrate is a plastics film, an elastic film, or a composite film.

The step of applying the substrate against the bottom face of the base prior to solidification of said bottom face of the base is then typically performed in such a manner that the surface area of the substrate in contact with the bottom face of the base is greater than the surface area of the substrate projected onto the bottom face of the base, in particular once the base has cooled.

In an example, following the step of applying the substrate, the base and the hooks are cooled in such a manner as to cause the material forming the base to shrink, thereby causing local deformation of the bottom face of the base, this deformation giving rise to deformation of the top face of the substrate secured thereto.

In another variant, the substrate is a set of thermally-consolidated fibers and/or filaments.

In an example, the substrate is applied in non-uniform manner against the bottom face of the base so as to obtain non-uniform bonding between the base and the substrate.

In an example, the substrate is applied in uniform manner against the bottom face of the base so as to obtain substantially uniform bonding between the base and the substrate.

In an example, the step of forming the tape of retaining elements makes elements in relief projecting from and/or recessed in the bottom face of the base and distinct from the retaining elements, and wherein the step of applying the substrate against the bottom face of the base provides bonding between the substrate and the base via said elements in relief.

In an example, during the step of forming the tape of retaining elements;a molding strip is provided that presents an inside face and an outside face, and that has a plurality of cavities, each cavity defining a stem extending from the outside face towards the inside face and including an end forming a head that extends from the stem towards the inside face of the molding strip;the molding strip is positioned on rotary drive means (e.g. comprising at least two rollers), the inside face of the molding strip being arranged to bear against the drive means; andmolding material is dispensed against the outside face of the molding strip via material dispenser means arranged facing the molding strip in such a manner as to define a gap between the material dispenser means and the molding strip, the molding material being dispensed in such a manner as to fill said gap and the cavities with molding material so as to form a tape comprising a base of thickness that is defined by the gap, and first preforms projecting from said base, each comprising a stem and a head, the first preforms being formed by the plastics material in the cavities of the molding strip.

In an example, during unmolding, the strip and the first preforms are unmolded in such a manner as to deform the first preforms plastically so as to obtain second preforms of shape that is different from the first preforms.

It is then possible, after the unmolding step, to perform a forming step during which the unmolded tape is inserted into a forming device so as to modify the shape of the heads of the second preforms by forming.

The step of dispensing the molding material is typically performed in such a manner as to form a tape extending in a longitudinal direction and comprising a base presenting two edges in the longitudinal direction, each of the edges presenting highs and lows, wherein the maximum offset between the highs and the lows is less than 1.0 mm over a length in the longitudinal direction corresponding to three consecutive highs, and wherein the step of applying the substrate against the bottom face of the base conserves this maximum offset in a direction transverse to the longitudinal direction between the highs and lows at less than 1 mm over a length in the longitudinal direction corresponding to three consecutive highs.

This third aspect also provides apparatus for performing a method as described above;a molding device and molding material dispenser means adapted to form a tape of retaining elements comprising a base presenting a bottom face and a top face, the top face of the base being provided with retaining elements; andsubstrate drive means, adapted to apply the substrate against the bottom face of the tape of retaining elements downstream from the molding material dispenser means.

In an example, said drive means comprise at least one roller.

Said roller is typically configured so as to press in non-uniform manner against the bottom face of the base so as to provide non-uniform bonding between the base and the substrate.

This third aspect also provides a retaining device, comprising a plastics tape extending in the longitudinal direction comprising a base presenting a bottom face and a top face and including a plurality of retaining elements extending from said top face, and a substrate secured to the bottom face of the base;

the retaining device being characterized in that the substrate penetrates into the base beyond a mean plane defined by the bottom face of the base of the tape.

In an example, the substrate is a layer of nonwoven material, and wherein portions of fibers and/or filaments of the layer of nonwoven material are encapsulated in the base.

In a variant, the substrate is a plastics film, an elastic film, or a composite film, and wherein the surface area of the film in contact with the bottom face is greater than the surface area of the projection of the surface of the film onto a plane defined by the bottom face of the base.

Fourth Aspect of the Disclosure

In a fourth aspect, the present disclosure provides a method of forming a retaining device with hooks, wherein:a molding strip is provided that presents an inside face and an outside face, and that has a plurality of cavities, each cavity defining a stem extending from the outside face towards the inside face and including an end forming a head that extends from the stem towards the inside face of the molding strip;the molding strip is positioned on rotary drive means comprising at least two rollers, the inside face of the molding strip being arranged to bear against the drive means;molding material is dispensed against the outside face of the molding strip by material dispenser means arranged facing the molding strip in such a manner as to define a gap between the material dispenser means and the molding strip, the step of dispensing the molding material being performed in such a manner as to fill said gap and the cavities with molding material so as to form a tape comprising a base of thickness that is defined by the gap, and first preforms projecting from said base, each comprising a stem and a head, the first preforms being formed by the plastics material in the cavities of the molding strip; andthe strip and the first preforms are unmolded in such a manner as to deform the first preforms plastically so as to obtain second preforms of shape that is different from the first preforms.

In an example, after the unmolding step, a forming step is performed during which the unmolded tape is inserted into a forming device so as to modify the shape of the heads of the second preforms by forming.

In an example, the forming device comprises at least two rotary elements, each of said rotary elements having a speed that is different from the drive speed of the tape.

In an example, the molding material is polypropylene, and wherein during the forming step, at least one forming element of the forming device is maintained at a temperature lying in the range 75° C. to 165° C., in particular substantially equal to 120° C., or indeed substantially equal to 140° C., or more precisely substantially equal to 150° C.

In an example, the step of unmolding the tape and the first preforms leads to a change in the height of the head and/or of the stem, and/or to a change in the width of the head and/or of the stem.

In an example, the forming device comprises an element at ambient temperature (or at a non-regulated temperature), and at least one element at a temperature that lies strictly between the heat deflection temperature (HDT) and the melting temperature of the molding material.

In an example, the forming step produces at least one deformation of a portion of the head of each of the second preforms, said deformation tending, for each preform, to deform one of the ends of the head of the preform so as to form a rib on the top face of the head of the preform.

In an example, during the step of dispensing the molding material, the gap between the material dispenser means and the molding strip lies in the range 10 μm to 700 μm, more particularly in the range 10 μm to 500 μm, or more precisely in the range 50 μm to 100 μm.

In an example, the step of dispensing the molding material is performed in such a manner that the molding material is dispensed while the inside face of the molding strip is bearing against a molding strip drive roller.

In an example, the step of dispensing the molding material is performed through a sheet of nonwoven material arranged on the molding strip, said sheet of nonwoven material including empty zones allowing the molding material to pass through.

The molding material is then typically polypropylene or a formulation based on polypropylene, and the step of dispensing the molding material is typically performed at a pressure lying in the range 10 bar to 100 bar, or indeed in the range 30 bar to 50 bar, and at a temperature lying in the range 150° C. to 300° C.

The molding strip is then typically driven at a travel speed lying in the range 1 meter per minute (m/min) to 500 m/min, more particularly in the range 5 m/min to 250 m/min.

In an example, the unmolding step is performed while the base of the tape is at a temperature lower than the melting temperature of the molding material, or lower than the heat deflection temperature of the molding material.

In an example, the step of dispensing the molding material is performed so as to form a tape extending in a longitudinal direction and comprising a base presenting two edges in the longitudinal direction, each of the edges presenting highs and lows, wherein the maximum offset between the highs and the lows in a direction transverse to the longitudinal direction is less than 1.0 mm over a length in the longitudinal direction corresponding to three consecutive highs.

In an example, prior to the unmolding step, a layer of nonwoven material is applied against the bottom face of the base before the bottom face of the base has solidified so as to cause portions of the fibers and/or filaments of the layer of nonwoven material to penetrate into the base, at least in part.

During the step of applying the nonwoven material against the bottom face of the base, the layer of nonwoven material is then typically at ambient temperature (or at a temperature that is not regulated), and the temperature of the base is the result only of the step of forming the tape.

During the step of applying the layer of nonwoven material against the bottom face of the base, the bottom face of the base is typically at a temperature lower than its melting temperature.

This fourth aspect also provides apparatus for performing a method as defined above, and comprising:a molding device, comprising a molding strip mounted on rotary drive means (e.g. comprising at least two rollers), the molding strip having an inside face and an outside face, the inside face being mounted to bear against the rollers, the molding strip having a plurality of cavities, each cavity defining a stem extending from the outside face towards the inside face, and including an end forming a head extending from the stem towards the inside face of the molding strip;material dispenser means arranged facing the molding device, and configured in such a manner as to dispense molding material at a point of the molding strip so as to form a tape of preforms having a base of thickness defined by a gap between the material dispenser means and the molding strip, and first preforms, each comprising a stem and a head projecting from said base; andunmolding means configured to unmold the tape of preforms formed in the molding strip;the molding strip and the unmolding means being configured so that unmolding the tape of preforms leads to the first preforms being deformed in such a manner as to form second preforms of a shape that is different from the first preforms.

In an example, the apparatus further comprises a forming device configured to modify the heads of the preforms by forming.

In an example, the apparatus further comprises drive means for driving a layer of nonwoven material and adapted to press a nonwoven material against the bottom face of the base of the tape of retaining elements downstream from the material dispenser means.

This fourth aspect further provides apparatus for forming a retaining device with hooks, the apparatus comprising:a molding device, comprising a molding strip mounted on rotary drive means (e.g. comprising at least two rollers), the molding strip having an inside face and an outside face, the inside face being mounted to bear against the rollers, the molding strip having a plurality of cavities, each cavity defining a stem extending from the outside face towards the inside face, and including an end forming a head extending from the stem towards the inside face of the molding strip;material dispenser means arranged facing the molding device, and configured in such a manner as to dispense molding material at a point of the molding strip so as to form a tape of preforms having a base of thickness defined by the gap, and first preforms, each comprising a stem and a head projecting from said base; andunmolding means configured to unmold the tape of preforms formed in the molding strip;

the molding strip and the unmolding means being configured so that unmolding the strip of preforms leads to the first preforms being deformed in such a manner as to form second preforms of a shape that is different from the first preforms.

In an example, this apparatus further comprises a forming device configured to modify the heads of the preforms by forming.

In an example, the forming device comprises at least two rotary elements, one of said rotary elements including heater means or temperature regulator means configured so as to maintain it at a temperature that lies strictly between the heat deflection temperature and the melting temperature of the molding material.

In another embodiment, the head may be heated prior to the forming step so that it is at a temperature lying between the heat deflection temperature of the molding material and the melting temperature of the molding material, the forming device including an element operating at a temperature that is less than the heat deflection temperature of the molding material, for example.

In an example, said rotary elements of the forming device have respective speeds that are different from that of the molding device.

In an example, the forming means are configured so as to form at least one fold in the head of each preform. More particularly, said at least one fold tends to fold at least one end of the head of the preform towards a central portion of the head of the preform.

In an example, the forming device comprises a rotary element configured in such a manner as to operate at ambient temperature or at a non-regulated temperature, and at least one a rotary element having heater means adapted so that said at least one rotary element operates at a temperature that lies strictly between the heat deflection temperature and the melting temperature of the molding material.

In an example, the rotary elements of the forming device are configured so as to be driven in rotation at distinct speeds of rotation, the rotary element having the lower temperature having a relative speed that is different from the rotary element(s) having a higher temperature.

In an example, the cavities of the molding strips extend in a cavity direction that is substantially perpendicular to the outside face of the molding strip, and each defines a stem and a head, each presenting symmetry of rotation about said cavity direction, the head having a dimension that is greater than the maximum dimension of the stem as measured radially relative to the cavity direction.

In an example, the material dispenser means are configured so as to dispense the molding material at a point of the molding strip while the inside face of the molding strip is pressing against a roller of the rotary drive means.

In an example, the gap between the material dispenser means and the molding strip lies in the range 10 μm to 700 μm, more particularly in the range 20 μm to 500 μm, or more precisely in the range 50 μm to 100 μm.

In an example, the rotary drive means for driving the molding strip comprise at least two rollers, each having a diameter lying in the range 10 times to 10,000 times the thickness of the molding strip, in particular in the range 50 times to 5000 times the thickness of the molding strip, e.g. in the range 100 mm to 250 mm.

In an example, the apparatus further comprises means for pressing a strip of nonwoven material and/or of woven material and/or of knitted material against the molding strip upstream from the material dispenser means.

In an example, the cavities in the molding strip are through cavities.

In an example, the apparatus further comprises a scraper device arranged on the inside face of the molding strip, downstream from the material dispenser means.

In an example, the molding strip includes an inner strip made of rubber forming its inside face, the ends of the cavities of the molding strip being formed in said inner strip made of rubber.

Fifth Aspect of the Disclosure

In a fifth aspect, the present disclosure provides a method of forming a retaining device with hooks, wherein:a molding strip is provided that presents an inside face and an outside face, and that has a plurality of cavities, each cavity defining a stem extending from the outside face towards the inside face and including an end forming a head that extends from the stem towards the inside face of the molding strip;the molding strip is positioned on rotary drive means comprising at least two rollers, the inside face of the molding strip being arranged to bear against the drive means;molding material is dispensed against the outside face of the molding strip by material dispenser means arranged facing the molding strip in such a manner as to define a gap between the material dispenser means and the molding strip, the step of dispensing the molding material being performed in such a manner as to fill said gap and the cavities with molding material so as to form a tape comprising a base of thickness that is defined by the gap, and first preforms projecting from said base each comprising a stem and a head, the first preforms being formed by the plastics material in the cavities of the molding strip;the tape and the first preforms are unmolded; andthe unmolded tape is inserted in a forming device so as to modify the shapes of the heads of the preforms by forming.

In an example, during the step of unmolding the tape and the first preforms, the first preforms are deformed plastically so as to obtain second preforms of shape that is different from the shape of the first preforms, said second preforms subsequently being deformed by the forming device.

In an example, the forming device comprises at least two rotary elements, each of said rotary elements having a speed that is different relative to the tape.

In an example, the molding material is polypropylene, and wherein during the forming step, at least one forming element of the forming device is maintained at a temperature lying in the range 75° C. to 165° C., and in particular close to 120° C.

In an example, the step of unmolding the tape and the first preforms leads to a change in the height of the head and/or of the stem, and/or to a change in the width of the head and/or of the stem.

In an example, the forming device comprises an element at ambient temperature or at a non-regulated temperature, and at least one element at a temperature that lies strictly between the heat deflection temperature (HDT) and the melting temperature of the molding material.

In an example, the forming step produces at least one deformation of a portion of the head of each of the second preforms, said deformation tending, for each preform, to deform one of the ends of the head of the preform so as to form a rib on the top face of the head of the preform.

In an example, the step of dispensing the molding material is performed in such a manner that the molding material is dispensed while the inside face of the molding strip is bearing against a molding strip drive roller.

In an example, the step of dispensing the molding material is performed through a sheet of nonwoven material arranged on the molding strip, said sheet of nonwoven material including empty zones allowing the molding material to pass through.

In an example, during the step of dispensing the molding material, the gap between the material dispenser means and the molding strip lies in the range 10 μm to 700 μm, more particularly in the range 10 μm to 500 μm, or more precisely in the range 50 μm to 100 μm.

The molding material is then typically polypropylene, and the step of dispensing the molding material is typically performed at a pressure lying in the range 10 bar to 100 bar, or indeed in the range 30 bar to 50 bar, and at a temperature lying in the range 150° C. to 300° C.

The molding strip is then typically driven at a travel speed lying in the range 1 m/min to 500 m/min, more particularly in the range 5 m/min to 250 m/min.

In an example, the unmolding step is performed while the base of the tape is at a temperature lower than the melting temperature of the molding material, or lower than the heat deflection temperature of the molding material.

In an example, the step of dispensing the molding material is performed so as to form a tape extending in a longitudinal direction and comprising a base presenting two edges in the longitudinal direction, each of the edges presenting highs and lows, wherein the maximum offset between the highs and the lows in a direction transverse to the longitudinal direction is less than 1.0 mm over a length in the longitudinal direction corresponding to three consecutive highs.

In an example, prior to the unmolding step, a layer of nonwoven material is applied against the bottom face of the base before the bottom face of the base has solidified so as to cause portions of the fibers and/or filaments of the layer of nonwoven material to penetrate into the base, at least in part.

In an example, during the step of applying the nonwoven material against the bottom face of the base, the layer of nonwoven material is at ambient temperature or at a temperature that is not regulated, and the temperature of the base is the result only of the step of forming the tape.

In an example, during the step of applying the strip of nonwoven material against the bottom face of the base, the bottom face of the base is at a temperature lower than its melting temperature.

This fifth aspect also provides apparatus for performing a method as defined above, and comprising:a molding device, comprising a molding strip mounted on rotary drive means e.g. comprising at least two rollers), the molding strip having an inside face and an outside face, the inside face being mounted to bear against the rollers, the molding strip having a plurality of cavities, each cavity defining a stem extending from the outside face towards the inside face, and including an end forming a head extending from the stem towards the inside face of the molding strip;material dispenser means arranged facing the molding device, and configured in such a manner as to dispense molding material at a point of the molding strip so as to form a tape of preforms having a base of thickness defined by the gap, and first preforms each comprising a stem and a head projecting from said base;unmolding means configured to unmold the tape of preforms formed in the molding strip; anda forming device, configured to modify the heads of the preforms by forming.

In an example, the molding strip and the unmolding means are configured so that unmolding the strip of preforms leads to the first preforms being deformed in such a manner as to form second preforms of a shape that is different from the first preforms.

In an example, the apparatus further comprises drive means for driving a layer of nonwoven material and adapted to press a nonwoven material against the bottom face of the base of the tape of retaining elements downstream from the material dispenser means.

This fifth aspect also provides apparatus for forming a retaining device with hooks, the apparatus comprising:a molding device, comprising a molding strip mounted on rotary drive means, e.g. comprising at least two rollers, the molding strip having an inside face and an outside face, the inside face being mounted to bear against the rollers, the molding strip having a plurality of cavities, each cavity defining a stem extending from the outside face towards the inside face, and including an end forming a head extending from the stem towards the inside face of the molding strip;material dispenser means arranged facing the molding device, and configured in such a manner as to inject molding material at a point of the molding strip so as to form a tape of preforms having a base of thickness defined by the gap, and first preforms each comprising a stem and a head projecting from said base; andunmolding means configured to unmold the tape of preforms formed in the molding strip;

the molding strip and the unmolding means being configured so that unmolding the strip of preforms leads to the first preforms being deformed in such a manner as to form second preforms of a shape that is different from the first preforms.

In an example, the apparatus further comprises a forming device configured to modify the heads of the preforms by forming.

In an example, the forming device comprises at least two rotary elements, one of said rotary elements including heater means or temperature regulator means configured so as to maintain it at a temperature that lies strictly between the heat deflection temperature and the melting temperature of the molding material.

In an example, said rotary elements of the forming device have respective speeds that are different from that of the molding device.

In an example, the forming means are configured so as to form at least one fold on the head of each preform, said at least one fold tending to fold at least one end of the head of the preform towards a central portion of the head of the preform.

In an example, the forming device comprises a rotary element configured in such a manner as to operate at ambient temperature or at a non-regulated temperature, and at least one rotary element having heater means adapted so that said at least one rotary element operates at a temperature that lies strictly between the heat deflection temperature and the melting temperature of the molding material.

In an example, the rotary elements of the forming device are configured so as to be driven in rotation at distinct speeds of rotation.

In an example, the cavities of the molding strips extend in a cavity direction substantially perpendicular to the outside surface of the molding strip, and each defines a stem and a head, each presenting symmetry of rotation about said cavity direction, the head having a dimension that is greater than the maximum dimension of the stem as measured radially relative to the cavity direction.

In an example, the material dispenser means are configured so as to inject the molding material at a point of the molding strip while the inside face of the molding strip is pressing against a roller of the rotary drive means.

In an example, the gap between the material dispenser means and the molding strip lies in the range 10 μm to 700 μm, more particularly in the range 20 μm to 500 μm, or more precisely in the range 50 μm to 100 μm.

In an example, the rotary drive means for driving the molding strip comprise at least two rollers, each having a diameter lying in the range 10 times to 10,000 times the thickness of the molding strip, in particular in the range 50 times to 5000 times the thickness of the molding strip, e.g. in the range 100 mm to 250 mm.

In an example, the apparatus further comprises means for pressing a strip of nonwoven material against the molding strip upstream from the material dispenser means.

In an example, the cavities in the molding strip are through cavities.

In an example, the apparatus further comprises a scraper device arranged on the inside face of the molding strip, downstream from the material dispenser means.

In an example, the molding strip includes an inner strip made of rubber forming its inside face, the ends of the cavities of the molding strip being formed in said inner strip made of rubber.

Sixth Aspect of the Disclosure

In a sixth aspect, the present disclosure relates to a retaining device comprisingan elastic film extending in a longitudinal direction;

a plastics tape extending in the longitudinal direction comprising a base presenting a bottom face and a top face and including a plurality of retaining elements extending from said top face;

the retaining device being characterized in that the film, the base, and the retaining elements are formed integrally by means of extrusion.

In an example, the film, base, and the retaining elements are formed integrally by successive and/or simultaneous extrusion operations.

In an example, the transition between the elastic film and the base of the tape, beside the top face and/or the bottom face, is continuous.

In an example, the plastics tape and the elastic film form an intermediate layer having a bottom face and a top face, said device further comprising a layer of nonwoven material secured to at least a portion of the bottom face of the intermediate layer.

The securing is then typically performed by partial encapsulation in said intermediate layer.

The partial encapsulation is typically performed in the elastic film of the intermediate layer.

The partial encapsulation is typically performed in the plastics tape of the intermediate layer. The partial encapsulation may be performed in the plastics tape of said intermediate layer and in the elastic film of said intermediate layer.

In an example, the device further comprises a nonwoven layer secured to the top face of the intermediate layer.

The nonwoven layer is then typically secured to the top face of the intermediate layer by means of adhesive.

In an example, at least one of the bottom face and/or of the top face of the intermediate layer presents elements projecting from said face, which projecting elements are distinct from the retaining elements.

The projecting elements are typically in the form of spikes.

In an example, the base of the plastics tape presents a thickness lying in the range 10 μm to 700 μm, where the thickness is the distance between the top face and a bottom face, each of the retaining elements is constituted by a stem and by a head;

the stem having a bottom end connected to the base, and a top end opposite from the bottom end, the head surmounting the top end of the stem, and having a bottom face facing towards the base and a top face opposite from the bottom face, and wherein the top face of the head of each retaining element includes a rib.

In an example, the nonwoven layer is activated. The nonwoven material may be activated prior to lamination or indeed the laminate may be activated over its entire width.

This sixth aspect also provides a method of forming a retaining device with hooks, wherein:a plastics material in the molten state is dispensed in a molding device so as to form a tape having a base and retaining elements projecting from a face of said base; andan elastic material in the molten state is dispensed;

in such a manner that the plastics tape and the elastic film and the retaining elements are made integrally by extrusion, the tape of plastics material and the elastic film forming an intermediate layer.

In an example, the elastic film is formed to extend the tape.

In an example, after making the intermediate layer, a step is performed of applying a nonwoven layer against the bottom face of the intermediate layer before said bottom face of the intermediate layer solidifies, in such a manner as to cause portions of fibers and/or filaments of the nonwoven layer to penetrate at least in part into the intermediate layer.

During the step of applying the nonwoven layer against the bottom face of the intermediate layer, the layer of nonwoven material is typically at ambient temperature or at a non-regulated temperature, and the temperature of the bottom face of the intermediate layer is the result solely of the step of making the intermediate layer.

In an example, the method includes the step of applying a layer of nonwoven material against the top face of the intermediate layer.

The layer of nonwoven material is then typically bonded to the top face of the intermediate layer, typically by using an adhesive.

In an example, prior to forming the intermediate layer, a support layer is positioned on at least a portion of the molding device.

In an example, the method includes a prior step of activating the layer(s) of nonwoven material.

In an example, prior to dispensing material, a molding strip is provided presenting an inside face and an outside face, and having a plurality of cavities, each cavity defining a stem extending from the outside face towards the inside face, and including an end that forms a head extending from the end of the stem towards the inside face of the molding strip, the molding strip is positioned on rotary drive means, e.g. comprising at least two rollers, the inside face of the molding strip being arranged to press against the drive means;molding material is then dispensed by material dispenser means arranged facing the molding strip in such a manner as to define a gap between the material dispenser means and the molding strip, the molding material being dispensed in such a manner as to fill said gap and the cavities with molding material so as to form a tape comprising a base of thickness that is defined by the gap, and first preforms projecting from said base, each comprising a stem and a head, the first preforms being formed by the plastics material in the cavities of the molding strip; and

wherein the dispensing of material is followed by an unmolding step in which the tape and the first preforms are unmolded in such a manner as to deform the first preforms plastically so as to obtain second preforms of shape that is different from the shape of the first preforms.

After the unmolding step, a forming step is typically performed during which the unmolded tape is inserted into a forming device so as to modify the shape of the heads of the second preforms by forming.

