ELASTIC LAMINATE AND REINFORCED NON-WOVEN FABRIC

Description

[0001] The present invention relates to a laminate comprising at least one elastic film bonded by adhesive to at least one nonwoven layer, in particular two nonwoven layers, one upper and one lower. This type of laminate is used, in particular, in clothing applications, especially disposable clothing such as diapers and adult incontinence devices, or in the medical field, in the form of elastic bandages. In diapers, these laminates are typically used in the parts forming the waistband around the baby's waist.In the case of a particularly advantageous application for diapers, these laminates are used to make the elastic flaps which ensure that the diaper is held firmly on the baby, in particular elastically, the flap, forming a hook part, bearing for example male elements of a hook fastener, in particular hooks, intended for example to cooperate with loops of a central part of the waistband of the diaper.

[0002] Laminates of this kind are already known in the prior art, notably in French patent application no. 05 11343 filed on November 8, 2005, in the name of the applicant. The laminates described therein are intended, in particular, to be fixed on one side to the frame of the layer and on the other side to a narrow strip with hooks. The nonwovens constituting these prior art laminates are either nonwovens that have no stretch capacity or nonwovens that can be stretched in one direction. In the case of non-stretch nonwovens, it is necessary, in order for the laminate to have elastic properties, to "activate" it, notably by partially breaking the constituent fibers or at least by reducing their cohesion, particularly by cutting with blades, in order to confer elasticity to the laminate as a whole.

[0003] From US-A-6245401, a laminate is known, comprising a layer, consisting of an elastic film and two less elastic but vapor-permeable films, and a non-woven layer, which can be used as the liquid-impermeable outer covering of a diaper frame.

[0004] From US-A-5773374, a laminate is known comprising two layers of nonwoven fabric sandwiching an elastic element. This elastic element consists of a core made of an elastic material and two outer skins on either side of the core. These outer skins have been previously stretched and bonded to the core, which is itself in a stretched state. Once bonded, the skins contract along with the core to form corrugations. The element, consisting of the core and the two outer skins, thus possesses elasticity between its rest length and its maximum length when stretched, such that the skins no longer form corrugations. The manufacturing process for this laminate is therefore complex and time-consuming.

[0005] From WO-A-01 / 53076, a laminate is known, comprising two layers of nonwoven fabric sandwiching a single-piece layer of an elastic material. Furthermore, between the elastic layer and the nonwoven fabric layer, a non-elastic reinforcing film is interposed, with adhesive applied to both sides of the reinforcing film to bond it to the nonwoven fabric on one side and to the elastic layer on the other. This bonding of several films makes the manufacturing process of the laminate complex and time-consuming.

[0006] From US 2005 / 0060849A1, it is known to co-extrude two strips, one in an elastomeric material and the other in a thermoplastic material in which hooks can be molded, the co-extrusion being done on a support layer, without interposition of glue, then the two co-extruded strips are separated from each other by pulling in the CD direction to obtain in the end individual hook elements.

[0007] From US 2007 / 157441A1, it is known to fix the underside of the web of the hook element to a reinforcement area, the underside being below the topside of the top layer of nonwoven fabric, while the hooks of the hook element protrude beyond the topside of the top layer of nonwoven fabric.

[0008] In both cases, it is difficult either to produce the laminate, particularly because it consists of a large number of parts, which makes it complex, or to ensure the high-speed attachment of the laminate to either the frame of the diaper or the hook flap, unless high-grammage top and bottom non-woven materials are used, which has an adverse effect on large-scale production costs.

[0009] Following a previous technique, it is known to treat areas of the nonwoven fabric(s) to eliminate the elastic properties of the laminate in those areas, for example by adding an extra layer of rigid film or nonwoven fabric on top of the laminate's thickness. However, in this case as well, the treatment is expensive and not well-suited to implementation on high-speed, large-scale production lines.

[0010] The present invention aims to overcome the disadvantages of the prior art by proposing a laminate, comprising at least one elastic film fixed by adhesive between two layers of non-woven fabric, which can be obtained in a very simple manner, particularly suitable for very large-scale manufacturing and which at the same time is simpler to assemble to a diaper, and in particular to the frame of the diaper, and to which it is also easier to assemble a narrow-width element having hooks to form a hooked part to allow the closure of this diaper.

[0011] According to the invention, a hook part of a self-fastening hook and loop closure, in particular for a diaper, is as defined in claim 1, improvements being defined in subclaims 2 to 7.

[0012] According to the invention, a single-piece layer is understood to be a layer that is not formed by bonding together several pieces, particularly films, using an intermediate bonding means, such as an adhesive or glue. In particular, a single-piece layer is a layer obtained by extruding a material or by co-extruding several materials.

[0013] In particular, said elastic film-shaped zone is in direct contact with at least one layer of non-woven material, with only possibly an interposed layer of adhesive, in particular glue.

[0014] Preferably, the laminate has a width measured in the transverse direction between the two left and right end edges, a thickness measured in the stacking direction of the laminate layers and a length in the direction perpendicular to the width direction and the thickness direction, the layers or sheets of non-woven and adhesive extending over the entire width of the laminate, while the sum of the widths of the elastic film-shaped area(s) is strictly less than the width of the laminate and the sum of the widths of the reinforcing film-shaped area(s) is also strictly less than the width of the laminate.

[0015] In particular, according to a preferred embodiment of the invention, the reinforcing film-shaped area(s) and the elastic film-shaped area(s), before being attached to at least one layer of nonwoven fabric, are formed into a single piece or film by coextrusion such that their lateral edges are in mutual contact. The materials of the reinforcing film(s) and the elastic film(s), for example thermoplastic and elastomeric materials, are extruded contiguous to one another, so that the reinforcing film(s) and the elastic film form a single piece.

[0016] Preferably, the reinforcing film-shaped zone(s) are made of a material, from a formulation or recipe incorporating, in particular, thermoplastic materials, possibly elastomeric, which, at isoload according to the elongation test method described below, gives less elongation properties than the elastic film-shaped zone(s). Preferably, these zones are inelastic.

[0017] With the hooked part according to the invention, it is now possible to obtain, at the same basis weight of the nonwovens used, improved resistance to lateral tensile strength and good attachment of the hooked part at its edges to the frame of a diaper, or, for a lower basis weight of at least one of the nonwovens used, in particular between 5 and 20 g / m², preferably between 5 and 15 g / m², in particular between 5 and 10 g / m², as good an attachment as for hooked parts of the prior art comprising nonwovens of higher basis weight.

[0018] According to a preferred embodiment, the hook web, consisting of a base strip and a plurality of hooking elements from the strip, is fixed, for example by gluing, hot calendering, ultrasonic welding or the like, to an outer face of at least one non-woven forming the laminate, at the edge in an area which is above or below one of the reinforcement areas, in particular lateral ones.

[0019] According to another embodiment, the hooked web, consisting of a base strip and a plurality of hooking elements from the strip, is fixed, for example by gluing, hot calendering, ultrasonic welding or the like, to an outer face of at least one of the lateral and / or central reinforcement areas.

[0020] According to a preferred embodiment of the invention, the two layers of adhesive, in particular glue, between respectively each non-woven fabric and the layer of a piece or a single piece consisting of at least two film-shaped reinforcement zones and at least one film-shaped elastic zone are made in such a way that between the non-woven fabric and the part(s) forming an elastic zone of the intermediate layer, the adhesive is deposited in the form of strips separated from each other by strips without adhesive.

[0021] Either the non-woven fabric has an extension capacity in the transverse direction, in which case the separate adhesive strips allow the laminate to have elasticity, or the chosen non-woven fabric is not extensible, and it is then activated by stretching the whole thing transversely so that on the adhesive strips clumps of non-woven fibers will agglomerate, while between the adhesive strips hollow parts will form in the non-woven fabric, and, after stretching, the non-woven fabric will have crested and hollow shapes and can be stretched.

[0022] Preferably, the thickness of the layer of a single piece or unit, comprising the film-shaped reinforcement zone(s) and the film-shaped elastic zone(s), at the junctions between the reinforcement and elastic zones is substantially constant. In particular, at the junctions, each of the two zones has a smaller thickness in the junction region than in the vicinity of the junction, the sum of the thicknesses of the two film-shaped zones at the junction being substantially equal to the thickness of either of the film-shaped zones near the junction.

[0023] According to another embodiment, the junction between two elastic and reinforcing zones is made via a beveled interface.

[0024] Preferably, the sum of the widths of the elastic film zone(s) and the reinforcing film zone(s), including that of the central zone where provided, is substantially equal to the width of the laminate, so that the end reinforcing zones extend substantially exactly to the respective end edge of the laminate.

[0025] According to another application of great interest as well, the widths of the elastic film-shaped zone(s) and the reinforcing film-shaped zone(s), including that of the central zone when provided, are such that one of the two end reinforcing zones extends substantially exactly to the respective lateral edge while the other of the two end reinforcing zones extends beyond the respective lateral edge, so as to protrude out of the laminate.

[0026] According to yet another application of great interest, the widths of the elastic film-shaped zone(s) and the reinforcing film-shaped zone(s), including that of the central zone where provided, are such that one of the two end reinforcing zones extends substantially exactly to the respective lateral edge while the other of the two end reinforcing zones extends below their respective lateral edge, so as to form a selvage which consists only of one non-woven or two non-wovens and an intermediate adhesive layer.

[0027] However, for each of the film-shaped reinforcement zones, it can be considered, independently of the other, that it extends either exactly to its respective lateral edge, or beyond that respective edge, or below that respective edge.

[0028] The present invention also relates to a method for obtaining a hooked part according to the invention as defined in claim 10.

[0029] Preferably, the co-extruded film consisting of the elastic film(s) and the reinforcing film(s) is made of one or more impermeable materials, particularly impermeable to air and / or liquids.

[0030] According to another aspect of the invention, it relates to a diaper defined as having a front part, a back part and a crotch part connecting the front and back parts, and two intermediate lateral parts connecting the upper left and right lateral edges of the back part with the upper left and right lateral edges of the front part respectively, each intermediate part being fixedly joined, for example by welding, to a respective upper lateral edge of the back part, and each intermediate part comprising a laminate extending in a transverse direction between two lateral edges respectively left and right, comprising a laminate fixed to at least one non-woven layer by a layer of adhesive, in particular interposed between two non-woven layers and being fixed respectively by a layer of adhesive to each non-woven layer,the layer being in one piece or a single unit and comprising a film-shaped elastic zone, particularly made of an elastomeric material, characterized in that: , the layer of a piece or single piece includes at least one film-shaped end reinforcement zone extending from the film-shaped elastic zone towards one of the lateral edges; no elastic zone being between said one of the lateral edges and the film-shaped reinforcement zone; and the at least one film-shaped reinforcement zone being less stretchable than said film-shaped elastic zone, in particular is less elastic, and preferably is not elastic, for example is made of a thermoplastic material.

[0031] According to an advantageous embodiment, at least one hooked element, comprising a base band and hooks from the band, is fixed to the laminate, a looped element is fixed to the front part and the arrangement is such that the closure of the layer around the waist of the wearer is achieved by the cooperation between the hooks of the intermediate part and the loops of the front part.

[0032] According to another equally advantageous embodiment, the intermediate parts are fixed to the front part in a non-removable manner, for example by welding.

[0033] The present invention also relates to a diaper as defined in claim 11.

[0034] As an example, an embodiment of the invention is now described with reference to the drawings in which: there Figure 1 represents a schematic cross-sectional view of an embodiment of a laminate according to the invention; the Figure 2 represents a schematic cross-sectional view of another embodiment of a laminate according to the invention; the Figure 3 represents a perspective view of a production installation for a laminate according to the invention, in particular laminates of figures 1 et 2 ; there Figure 4 is a diagram representing a sample of elastic or elastomeric material prepared to determine its SET, the Figure 5 represents the shape of the hysteresis curve obtained when determining the SET of a material, particularly elastic or elastomeric. Figure 6 represents another embodiment of a laminate according to the invention, which corresponds to the laminate of the figure 1 to which an element with hooks was added on top. figures 7 à 20 represent other possible embodiments of a laminate according to the invention; The figure 21 represents a cross-sectional view of the stratum of the embodiment of the figure 1 after being formed by extrusion and before being assembled with one or two layers of non-woven fabric; The figure 22 represents a part of the view of the figure 21 of a layer having an elastic film-reinforcing film interface made at an angle; The figure 23 represents examples of curves showing stretch versus force for the relative stretch test; The figure 24 represents yet another embodiment of a laminate according to the invention; The figure 25 represents an embodiment of a diaper according to the invention incorporating an ear or tab for fastening with hooks incorporating a laminate as described in the preceding figures; The figure 26 represents, in perspective view, another embodiment of a diaper according to the invention; and The figure 27 represents yet another embodiment of a laminate according to the invention.

[0035] To the Figure 1 A laminate 1 is shown, comprising a lower first layer 2 of non-woven fabric and an upper second layer 3 of non-woven fabric. Between these two lower and upper layers 2 and 3 of non-woven fabric (the cross-sectional view is shown in the figure, knowing that the laminate as a whole is an element whose length is perpendicular to the plane of the figures 1 et 2 An intermediate layer 4 is formed. This intermediate layer 4 consists of a left-side reinforcing thermoplastic film 5, a left-side elastic elastomeric film 6, a central reinforcing thermoplastic film 7, a right-side elastic elastomeric film 8, and a right-side reinforcing thermoplastic film 9. Adhesive layers 10 and 11 are interposed between each nonwoven layer and the intermediate layer 4. The total width of the laminate is equal to the width of each nonwoven layer plus the width of each adhesive layer. The sum of the widths of the three reinforcing films and the two elastic films is equal to the width of the laminate.

[0036] The two reinforcing films, left and right, extend to the respective left and right edges of the laminate. Alternatively, a small selvage without reinforcing tape can be formed at each edge of the laminate (see the figure 13 ) or that, on the contrary, one or both films extend beyond the respective edge (see figures .7, 8, 11 ou 12 ). In all cases, one of the edges of the two end reinforcement films is the locus of the points of the set of end reinforcement films that are furthest from the elastic film(s).

[0037] As can be seen at the figure 21 The thickness of the layer, measured in the vertical direction in the figure—that is, perpendicular to the width and length directions of the flow—is constant or nearly constant over the transverse extent of each elastic or reinforcement zone. However, as can be seen in the same figure, the thickness of the elastic zones varies in an increasing and then decreasing manner, reaching a maximum between their two junctions with the reinforcement zones. Nevertheless, the thicknesses of the elastic film(s) and the reinforcement zone(s) are such that, at their respective junctions, the upper and / or lower surfaces of the layer are virtually smooth and without discontinuities.

[0038] Thus for example, the elastic film(s) have a weight approximately 10 to 25% greater than that of the reinforcing film(s), the elastic film(s) having for example a weight of 55 g / m² while the reinforcing film(s) have a weight of 45 g / m².

[0039] On the joint or connection section, which typically extends over a width of between 3 and 10 mm, often 5 mm, the thickness of each film (reinforcing and elastic) is less than the thickness of the film outside the joint. Thus, each film in the joint has a thinner section that overlaps with the thinner section of the other film in the joint. This overlap creates, at the interface between the two films, the effect shown in the diagram. figure 21 , a sort of step. The interface could also take the form of a bevel, as shown in the figure 22 .

[0040] However, in practice, at the interface between the two thermoplastic and elastic or elastomeric materials, small bulges may form due to the fact that the sum of the thicknesses of the overlapping end parts is slightly greater than the thicknesses of the two films on either side of the junction.

[0041] In the present invention, an elastic film or zone in a given direction is understood to be a film or zone that substantially recovers its initial shape after being stretched or elongated in the given direction, at room temperature. Preferably, it is a film or zone that retains only a small residual deformation or set after deformation and release (permanent set or SET), namely less than 10%, and more preferably less than 5% of the initial length, for an elongation of 100% of the initial length of the sample, at room temperature (T ~ 23°C).

[0042] Preferably, the elastic film is capable of an elongation at break of at least 300% at room temperature and, more preferably, an elongation of at least 600%, and even more preferably of at least 1000%, at room temperature and for a stretching speed of 508 mm / min. The material of which the elastic film is made can be either a pure elastomer, or mixtures having an elastomeric phase, or a material that still exhibits substantially elastomeric properties at room temperature, such as polyolefins produced by metallocene catalysis. It can also include a thermoplastic filler to, among other things, aid in the seamless formation of the layer with the reinforcing films.

[0043] To measure the remanence, or SET, of a sample, and thus determine if it is a sample of an element, in particular a film, elastic, the following method is used: The sample is conditioned in a normal atmosphere, as defined in the ASTDM 5170 standard, temperature of 23°C ± 2°C and relative humidity of 50% ± 5%.

[0044] We use as equipment a dynamometer conforming to the EN 10002 standard, in particular the Synergie 200H, 1 column available from the company MTS Systems Corp, USA, together with a TESTWORKS 4.04 B operating software.

[0045] The sample is prepared by cutting out a rectangular piece of the product whose elasticity we wish to measure (for example, 45mm wide in the MD direction (direction of the machine, perpendicular to the plane of the figure 1 ) and of a length in the CD direction (transverse direction, horizontal direction to the figure 1 ) of 60mm).

[0046] The sample is positioned between the jaws on either side of the area whose elasticity we wish to test, as schematically represented in the diagram. figure 4 ;

[0047] The parameters are selected as follows: Jaw-to-jaw distance: 20 mm Machine speed: 254 mm / min Number of cycles: 2 Product elongation: 100% at constant speed

[0048] The product is stretched to 100% by vertical movement of the jaws, after applying a preload of approximately 0.05 N. It is then held in this position for 30 seconds (first cycle), then returned to its initial position where it remains for 60 seconds. It is then stretched again to 100%, held for 30 seconds (second cycle), and returned to its initial position. The resulting curve shows the stretching force in N as a function of the elongation in %, exhibiting hysteresis, which can then be characterized by the SET (n=2), namely the point on the starting curve of the second cycle that intersects the X-axis (elongation in %). figure 5 .

[0049] Preferably, the elastic film is capable of an elongation at break of at least 300% at room temperature and, more preferably, an elongation of at least 600%, and even more preferably of at least 1000%, at room temperature and for a stretching speed of 508 mm / min. The material of which the elastic film is made can be either a pure elastomer, or mixtures having an elastomeric phase, or a material that still exhibits substantially elastomeric properties at room temperature, such as polyolefins produced by metallocene catalysis. It can also include a thermoplastic filler to, among other things, aid in the seamless formation of the layer with the reinforcing films.

[0050] The material of the elastic film, particularly elastomeric, can be a heat-shrinkable or non-heat-shrinkable elastic material. It can be formed, in particular, from polymers, such as copolymers of different types of monomer motif, for example alternating such as AB, or sequenced, for example AAABBB, or statistical, for example AABABBAAABA, whose entire network obtained can have different structures, either linear of the ABA type, or radial of the AB type, index n (n>2), or diblock of the AB type which are elastomeric, for example the styrene / isoprene (SI), styrene / isoprene / styrene (SIS), styrene / butadiene / styrene (SBS), styrene-ethylene / butylene-styrene (SEBS), styrene-ethylene / propylene-styrene (SEPS) or SIBS copolymers. Mixtures of these elastomers with each other or with non-elastomers modifying certain characteristics other than elasticity can also be considered.For example, up to 50% by weight but preferably less than 30% by weight of polymer may be added as a stiffening addition, such as polyvinyl styrene, polystyrene or poly α-methyl styrene, epoxy polyesters, polyolefins, for example polyethylenes or certain ethylene / vinyl acetates, preferably those of high molecular weight.

[0051] The elastic film material may be, in particular, a styrene-isoprene-styrene, available, for example, from Kraton Polymers under the name KRATON D (Registered Trademark), or from DEXCO POLYMERS LP under the name VECTOR SBC 4211 (Registered Trademark). A thermoplastic polyurethane elastomer may also be used, in particular PELLATHANE (Registered Trademark) 2102-75A from The Dow Chemical Company. A styrene-butadiene-styrene may also be used, in particular KRATON D-2122 (Registered Trademark) from Kraton Polymers, or VECTOR SBC 4461 (Registered Trademark) from Dexco Polymers LP. One can also use a styrene-ethylene / butylene, in particular KRATON G-2832 (Registered Trademark) from Kraton Polymers, or a sequenced styrene-ethylene-butylene-styrene (SEBS) copolymer, in particular KRATON (Registered Trademark) G2703.One can also use a copolymer of isooctyl acrylate and acrylic acid with monomer ratios of 90 / 10. One can also use a sequenced polyamide polyether copolymer PEBAX (Registered Trademark) 2533 from the company Arkema.

[0052] Other possible materials are polyolefin polymers with the characteristics of elastomers, in particular those produced by metallocene catalysis, such as VISTAMAXX VM-1120 (Trademark), available from Exxon Mobil Chemical, or EPDM-filled polymers of the Santoprene type.

[0053] In the case where glue is used as an adhesive to fix elastic films and thermoplastic films to non-wovens and possibly non-wovens to each other, according to the invention, a glue such as non-reactive hot melt glues, for example Bostik's H2511, or a reactive glue, in particular Bostik's AX75E, or reactive PU glues can be used.

[0054] Preferably, these adhesives will have a chemical nature similar to or compatible with a material composing the elastic film and / or the thermoplastic or reinforcing film described above.

[0055] Regarding nonwovens, spunbond, meltblown, carded calendered, and / or spunlace nonwovens can be used, with a base material of one or more polyolefins, preferably polypropylene, polyester, or a blend thereof. In particular, spunbond nonwovens are based on long fibers or filaments, with a dTex value (mass in grams divided by a length of 10,000 meters of yarn) between 1 dTex and 6 dTex, for example, 2.2 dTex. Especially when the laminate comprises two layers of nonwovens, the layers can be of different types and / or different materials.

[0056] Preferably the or at least one of the non-wovens or both non-wovens have a basis weight between 5 and 25 g / m2, in particular between 5 and 15 g / m2, more particularly between 5 and 10 g / m2.

[0057] In particular, when the nonwoven material lacks self-stretching capacity and requires activation, the basis weight is between 5 and 20 g / m², specifically around 15 g / m² for a spunbond or around 8 g / m² for a meltblown. When the nonwoven material does not require activation for the laminate to have elastic properties, that is, when the nonwoven material has self-stretching capacity over an elongation range of at least 50%, preferably at least 100%, the basis weight is preferably between 15 and 25 g / m², for example, 22 g / m² for a carded calendered or 25 g / m² for a spunlace. Furthermore, it should be noted that the two non-woven fabrics, in the case where there are two, may be different from each other.

[0058] To determine whether one element, particularly a film, is more stretchable than another element, for example another film, according to the invention, a stress elongation test until breakage can be used as follows: A dynamometer conforming to EN 10002 is used as apparatus, for example the same as for the elasticity test above, namely the Synergie 200H, 1 column, available from MTS Systems Corp, USA, in conjunction with TESTWORKS 4.04 B software. The sample is prepared in a rectangular shape, for example 45 mm wide and 60 mm long. The sample is positioned between the jaws on either side of the area whose elongation is to be tested, as schematically shown in the diagram. figure 4 The parameters are selected as follows: Jaw-to-jaw distance: 20 mm Machine speed: 254 mm / min Product elongation: until breakage at constant speed

[0059] After applying a preload of 0.05 N, the product is stretched until it breaks by vertically moving the jaws. For each sample, the characteristic curve is then obtained, showing the stretching force in N as a function of the elongation in %, as shown in the diagram. figure 23 Each curve has a peak point, from which the elongation increases with decreasing force. This peak corresponds to the point at which the element reaches a state of failure.

[0060] To determine which of two elements, particularly two films, is the least stretchable, we test both elements, specifically the two films, using the method described above, to obtain their respective characteristic curves. Each curve has a given apex point corresponding to a given elongation. We then choose as the reference elongation the smaller of the two given elongations of the two curves, or the given elongation in the case where the two given elongations are identical. For this smaller given elongation, we compare the two stretching forces of each curve, and the element with the greater stretching force for this reference elongation is the least stretchable element. Thus, for example, at the figure 23 , the reference elongation is the elongation corresponding to the peak point of film A, namely about 240% and at this reference elongation, the curve of film A gives a stretching force of about 40 N and the curve of film B a stretching force of about 32.5 N, so that film A is the least stretchable.

[0061] Regarding the material for the reinforcing strips, one can choose a single material or a blend of several materials, such as those from the thermoplastic family, for example polyethylene, polypropylene, polyester, or any similar material, as well as materials from the thermoplastic elastomer family used for the elastic film (provided, however, that the reinforcing film has less elongation than the elastic film). This ensures good compatibility of the materials forming the single-piece layer. A thermoplastic material with good compatibility with the elastic or elastomeric material of the elastic film should preferably be chosen so that the bond between them along their respective edges, after cooling, is as strong as possible.Specific examples of material for reinforcement films are polyethylene Riblene MV 10 (registered trademark) from Polimeri Europa, or MG 9621 from Boréalis, or LD259 or LD655 from Exxon Mobil Chemical.

[0062] Between the intermediate layer 4, consisting of sections 5, 6, 7, 8, and 9, adhesive layers 10 and 11 are provided. The adhesive strips 10 and 11 are continuous at the interface between each nonwoven and each reinforcing strip and consist of adhesive strips separated from each other by adhesive-free strip-like areas between the nonwovens and the elastic films. However, the reinforcing films and the nonwovens could also be not continuously bonded, for example, by also using separate adhesive strips at this level, or even by spot bonding or random spray bonding. The reinforcing strips and the elastic films are deposited between the two nonwovens by co-extrusion. They are each joined by co-extrusion, so that in the co-extrusion tooling, they come into contact along their respective lateral edges 12, 13, 14, and 17 in a softened and pressurized state.The close contact between the two softened edges of the elastic and reinforcing strips causes them to bond together within the tooling and maintain this bond after cooling. For example, the elastic film can be made of thermoplastic elastomer while the reinforcing strips can be thermoplastic, facilitating the mutual fastening of the two interfaces along their lateral edges.

[0063] To the figure 2 Another embodiment is shown in which the laminate comprises a film 18 consisting of a central elastic film 16 and two lateral reinforcing strips (15, 19). In this embodiment, there is no central reinforcing strip and only one elastic film. The other characteristics of the laminate of the figure 2 are identical to what has been described for the laminate of the figure 1 .

[0064] To the figure 3 A laminate manufacturing installation according to the invention is shown: the installation comprises an extruder 101 which forms, by extrusion, two ribbons 201, 202 of elastic films which, via belt systems 203 and rollers 204, are transported between two rollers simultaneously with two layers of non-woven material 301 and 401 to be fixed by cooling the elastomeric material between the non-woven layers in a fixing unit 500. The non-woven material 301 is unwound from a reel 302. The second non-woven material 401 is unwound from a reel 402. Three ribbons 203, 204, 205 of thermoplastic material are also formed from the extruder 102. The five ribbons 201 to 205 are co-extruded side by side with their edges contiguous, so that at the exit of the co-extrusion tooling and subsequently after cooling, they form only one single piece.The composite material, consisting of nonwovens 301 and 401 and elastic and thermoplastic ribbons 201 to 205, is known as composite 601. It is then laminated in a calender 600, cut to the correct width in a cutting system 700 equipped with circular knives 701, and then passes through a welding unit 800, which welds the longitudinal edges. Finally, the nonwovens are activated by defibrillation in an activation unit 900.

[0065] Upon exiting the activation unit 900, the laminate as a whole is wound onto a winder 1000 into a roll 1001 which can then be taken directly to the diaper manufacturing units for placement on a diaper.

[0066] Preferably, the elastic or elastomeric film(s) have a thickness between 20 microns and 120 microns. Similarly, the reinforcing strips preferably have the same thickness.

[0067] Depending on the application, the dimensions of the thermoplastic reinforcing films can be chosen so that one of them extends exactly to one of the left or right edges of the laminate, while at the other edge, either the strip also extends exactly to the right or left edge, or extends a small distance outside beyond the edge of the laminate, or on the contrary ends in retreat from this edge so as to form a small selvage, in particular without reinforcing film.

[0068] To the figure 6 we have represented the stratification of the figure 1 to which, in the area opposite or corresponding to the left-hand reinforcement band, a hook-and-loop fastener made of thermoplastic material has been attached to the upper non-woven fabric. This fastener consists of a thermoplastic band from which protruding fastening elements, in particular hooks. The width of this hook-and-loop band is less than the width of the reinforcement band. Such a band could also be provided above one or all of the other reinforcement bands in the embodiments of figures 1 et 2 Depending on the chosen application, this hook-and-loop strip(s) can be attached using adhesive, glue, or welding, including ultrasonic welding.

[0069] In the examples described above, two layers of identical non-woven fabric were used. It is also possible to use two layers of different non-woven materials or with different weights, or even to use a single layer of non-woven fabric instead of two.

[0070] In the examples described above, the reinforcement films were extruded from the same extruder 102. A third extruder could also be used to extrude one of the areas with a thermoplastic material formulation different from the other reinforcement area.

[0071] In the examples above, layer 4 comprises two elastic films and three reinforcing films. It is also possible to predict that this layer could be composed of multiple elastic and reinforcing zones, with a respective number greater than or equal to 4.

[0072] In addition, colorants may be added, in the form of a masterbatch, in liquid or powder form, up to 7%, preferably less than 1%, to the formulation of the elastic film(s) and / or the reinforcing film(s) to allow for easy readability.

[0073] Similarly, the formulation of each film is carried out according to the usual rules of the art in extrusion and may incorporate agents such as "processing aids", blowing agents, anti-UV, antiblock, etc.

[0074] At figures 7 à 20 Other embodiments of a laminate according to the invention are shown, in which, compared to the embodiments of figures 1 et 2 The number and / or widths of the non-woven layers, the number of elastic films, the number of reinforcing films, the widths of the reinforcing films, the relative positioning of the reinforcing films with respect to the edges of the laminate, and the positioning of an element with hooks were varied. Naturally, this description also includes embodiments obtained by combining two or more of the embodiments of... figures 1 , 2 , 6 à 18 , in particular when one takes from one of these embodiments one or more characteristics that are not found in another of the described embodiments and adds this characteristic or these characteristics from said one of these embodiments to said other embodiment. In these figures, the same numerical references as in figures 1 et 2 have been used to describe identical elements.

[0075] To the figure 7 , a laminate is described having only a top layer of non-woven material, which extends only over the two elastic films 6 and 8. Layer 4 has three reinforcing films 5, 7 and 9 and two elastic films 6 and 8.

[0076] To the figure 8 It represents a mode of embodiment substantially identical to that of the figure 7 except for the fact that it also includes a lower non-woven layer, which also only extends over the elastic films.

[0077] To the figure 9 , there is yet another embodiment which is substantially identical to that of the figure 7 except for the fact that a lower non-woven layer has been added which extends across the entire width of the intermediate layer, exactly from one edge of this layer to the other.

[0078] To the figure 10 It represents a mode of embodiment substantially identical to that of the figure 9 except that the lower non-woven layer extends beyond the lateral edges of the intermediate layer.

[0079] To the figure 11 It represents a mode of embodiment substantially identical to that of the figure 9 except that the lower non-woven layer extends below the lateral edges of the intermediate layer, with the two end reinforcement films protruding laterally beyond the two lower and upper non-woven layers.

[0080] To the figure 12 It represents a mode of embodiment substantially identical to that of the figure 1 except that the two end reinforcement films protrude laterally beyond the two lower and upper non-wovens.

[0081] To the figure 13 It represents a mode of embodiment substantially identical to that of the figure 1 except that the two end reinforcement films do not extend to the lateral edges of the laminate, remaining set back laterally from the two non-wovens.

[0082] To the figure 14 It represents a mode of embodiment substantially identical to that of the figure 1 except that the top non-woven layer does not extend to the end edges of the intermediate layer, with both reinforcing films and the bottom non-woven layer extending laterally beyond the top non-woven layer.

[0083] To the figure 15 It represents a mode of embodiment substantially identical to that of the figure 1 except that the top non-woven layer does not extend over the central film, leaving the latter exposed, a bare surface which can be used for the direct attachment of an element with hooks, as shown in the figure 18 .

[0084] To the figure 16 It represents an embodiment identical to that of the figure 6 except that the element with hooks is attached to the upper non-woven at the level of the central film and not at the level of one of the end reinforcement films.

[0085] To the figure 17 The method of implementation of the figure 14 to which was fixed on an end portion of the end reinforcement film which protrudes beyond the top layer of non-woven material an element having hooks.

[0086] To the figure 18 The method of implementation of the figure 15 to which was fixed on the exposed part of the central film an element with hooks.

[0087] To the figure 19 The figure shows a laminate consisting of only an elastic film and an end-reinforcing film. The reinforcing film extends from the elastic film to the lateral edge (left in the figure). The end edge of the reinforcing film on the side opposite the elastic film is the locus of the points on the end-reinforcing film furthest from any elastic film.

[0088] To the figure 20 , it is represented as a laminate in which the layer consists of five alternating reinforcing films and four elastic films.

[0089] To the figure 24 An embodiment of a laminate according to the invention is shown, comprising a top nonwoven layer and a bottom nonwoven layer. The intermediate layer comprises, in succession and co-extruded together, a reinforcing film, an elastic film, and another reinforcing film. During extrusion, the two reinforcing films tend to extend beyond the elastic film, forming a thin film over the elastic film. This film, made of reinforcing material (less stretchable than the elastomeric material), connects the two reinforcing films. Compared to the thickness of the elastic material, this film is sufficiently thin, however, for the laminate to retain its elasticity at the level of the elastic film. The film is in direct contact (with only adhesive interposed) with the top nonwoven layer.On the underside, there is direct contact between the elastomeric film and the lower non-woven fabric (with only dots or lines of adhesive in between), and between the reinforcing films and the lower non-woven fabric. At the... figure 27 A variant of the method of implementing the laminate is shown. figure 24 , the laminate of the figure 27 being identical to the laminate of the figure 24 except for the fact that it does not include the top non-woven layer and the intermediate adhesive layer between the co-extruded layer and the top non-woven layer. Thus, the top surface of this laminate of the figure 27 is it made up solely of the material forming the reinforcing band and the bridging part above the elastic layer, possibly with a hooked band attached to this upper surface.

[0090] To the figure 25 The diagram shows a diaper lying approximately flat and not folded back on itself. The diaper 100 consists of a frame formed by a stack of an outer waterproof cover 101 and a lining 102 on the body side that is permeable to bodily fluids. An absorbent material is placed between the cover and the lining.

[0091] The frame forms a front portion 104, intended to be located on the front side of the wearer when the diaper is worn, a rear portion 105, intended to be located on the rear side of the wearer when the diaper is worn, and a crotch portion 106, connecting the front and rear portions. On the front portion, on the outer face of the outer cover 101, a looped portion 107, for example in the form of a looped knit, looped woven fabric, or looped nonwoven fabric, has been arranged, for example by gluing, ultrasonic welding, or similar means.

[0092] From the two opposite edges of the rear part of the frame protrude intermediate sections 103 with hooks, made of one of the laminates described previously, to which hooks have been attached. These hooks are designed to cooperate with the loops from the front section to fasten the diaper around the wearer's waist. Specifically, the hooks are attached to one of the reinforcement bands, either directly onto it or with the non-woven layer above the reinforcement band in between.

[0093] The intermediate parts 103 are joined to the rear part on both sides thereof, preferably, as shown, substantially at the upper level of the rear part. This joining can be done directly or indirectly. For example, each intermediate part can be fixed directly to the rear part using adhesive, thermal welding, ultrasonic welding, or similar methods. An intermediate piece can also be provided to facilitate this joining, and the intermediate parts 103 can even be made in one piece or as a single unit with the rear part.The fixing of each intermediate part to the upper lateral edges of the rear part of the layer's frame is done at the level of the reinforcement strip or one of the reinforcement strips of the laminate constituting this intermediate part, either directly or with interposition of the non-woven layer located above this reinforcement strip, the presence of this reinforcement strip facilitating this fixing.

[0094] To the figure 26 Another embodiment of a layer according to the invention is shown. In this embodiment, the intermediate parts 103' are joined both to the rear part (as in the embodiment of the figure 25 ) and to the front part 104' in a manner analogous to the way the rear and intermediate parts are joined. The intermediate parts are also, as in the embodiment of the figure 25 , made of one of the laminates described above. The only difference is that in this embodiment the intermediate part 103' does not have hooks and the connection with the front part is not removable as is the case in the embodiment of the figure 25 through the cooperation of hooks and loops. Thus, in this method of implementation of the figure 26 It is not necessary to include a looped section in the front part. The attachment of each intermediate part to the upper lateral edges of the rear and front parts of the layer's frame is done at one of the respective reinforcement strips of the laminate constituting this intermediate part, either directly or with the interposition of the non-woven layer located above this reinforcement strip; the presence of the reinforcement strips facilitates this attachment.

Claims

1. Hook part of a self-gripping hook and loop closure, in particular for a nappy, comprising a hook element comprising a sheet having a lower face and an upper face, upper face from which hooks protrude and a laminated element fixed to the hook element, the laminate extending in a transverse direction between two respective left and right lateral edges, comprising two respective lower and upper layers of non-woven fabric , between which an integral layer extends itself, said integral layer comprising two film shaped elastic zones (6), notably in an elastomeric material, and at least one lateral film shaped reinforcement zone (5) and a central film shaped reinforcement zone extending between the two elastic zones, no elastic zone being present between said one of the lateral edge and said at least one lateral reinforcement zone; - the at least one lateral film shaped reinforcing zone (5) being less stretchable than said film shaped elastic zones, in particular being less elastic, and preferably being non elastic, for example being made of a thermoplastic material, - the at least one lateral film shaped reinforcement zone (5) and said reinforcement central zone being fixed by an adhesive layer to the lower non-woven fabric layer, the upper non-woven fabric layer extending on top of said two elastic zones, characterized in that the lower face of the sheet of the hook element is fixed directly to the central zone, the lower face being below the upper face of the upper non-woven fabric layer, while the hooks of the hooks element protrude beyond the upper face of the upper non-woven fabric layer.

2. Hook part according to Claim 1, characterised in that three reinforcement zones (5) are provided, namely two left and right edge zones and a central zone.

3. Hook part according to Claim 2, characterised in that the hooks element is fixed to the upper face of the reinforcement central zone.

4. Hook part according to one of Claims 1 to 3, characterised in that the hooks element is fixed to the reinforcement zone by an adhesive, notably glue.

5. Hook part according to one of Claims 1 to 4, characterised in that the hooks element is fixed to the reinforcement zone by ultrasound welding.

6. Hook part according to one of Claims 1 to 5, characterised in that the layers of non-woven fabrics each have a grammage ranging between 5 and 15 g / m2.

7. Nappy comprising a self-gripping closure having a loop part and a hook part according to one of Claims 1 to 6, each fixed or attached to the nappy so as to cooperate with one another to close the nappy, in particular in the region of the waistband of the nappy.