Holding device, absorbent item comprising a holding device and method of manufacturing a holding device
The retention device addresses oversizing issues by varying geometric dimensions in holding and intermediate areas, enhancing flexibility and reducing material usage, thus improving comfort and efficiency in hygiene products like diapers.
Patent Information
- Application Number
- JP2025186403
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2020-08-03
- Filing Date
- 2025-11-05
- Publication Date
- 2026-02-10
AI Technical Summary
Existing retention systems face challenges with reduced retention force due to manufacturing constraints, leading to oversizing issues that affect softness and increase material consumption, particularly in hygiene products like diapers, resulting in longer cooling times and increased production line occupancy.
A retention device with varying geometric dimensions, featuring higher dimensions in holding areas and lower dimensions in intermediate areas, allowing for increased flexibility and reduced material usage while maintaining effective retention, achieved through a manufacturing method involving controlled application of molding material in specific patterns.
The solution provides a retention device that is lighter, more flexible, and maintains effective retention over larger areas, improving user comfort and reducing material consumption and production time, while ensuring continuous retention without interruptions.
Smart Images
Figure 2026021500000001_ABST
Abstract
Description
[Technical Field]
[0001] The present disclosure relates to the field of retention systems, in particular closure or anti-slip systems, and more particularly to retention systems with retention elements, in particular hook-and-loop retention systems, in which the retention elements can be held by loops or the like.
[0002] The present disclosure also relates to a manufacturing method and an apparatus.
[0003] The present disclosure also relates to the field of absorbent items of the baby diaper or adult incontinence diaper type, comprising a hook and loop retention system for the diaper. [Background technology]
[0004] Retention systems comprising retention elements carried by a base are well known and used in many fields of application and in practice have led to the production of numerous forms of retention elements, in particular hooks, intended to cooperate with each other or with complementary elements such as loops.
[0005] A recurring problem with such products relates to the retention force applied, especially as the dimensions of the associated retention elements are significantly reduced, given manufacturing constraints.
[0006] In fact, the production of hooks with high strength necessarily leads to oversizing, which affects the softness of the system and therefore the sensation of the user, which is very disadvantageous in some sectors, especially in the hygiene sector, and leads to an increased consumption of material, which is disadvantageous in terms of costs, and is also disadvantageous in terms of production, since the production of bulky parts leads to an increased cooling time of the material, which in fact increases the occupation time of the production line.
[0007] Document WO2017187097 discloses a holding device comprising a holding element carried by a base and having particular dimensions and geometrical characteristics. Summary of the Invention [Problem to be solved by the invention]
[0008] The present disclosure aims to address these various problems by further improving such known devices. [Means for solving the problem]
[0009] According to a first aspect, the present disclosure relates to a holding device, the holding device comprising: a base extending along a longitudinal direction and having an upper surface and a lower surface; a plurality of retention devices extending from a top surface of the base, each retention device having a value according to a first geometric dimension; The holding device has at least two holding areas and an intermediate area arranged between the two holding areas and connecting the two holding areas, and the values according to a first geometric dimension of the holding devices arranged in the first and second holding areas are greater than the values according to the first geometric dimension of the holding device arranged in the intermediate area.
[0010] Optionally, the holding region and the intermediate region form an elongated region of the common tape form, the elongated region and the common tape form optionally extending along the longitudinal direction.
[0011] Optionally, the intermediate region has at least one portion having a base with a thickness that is less than the thickness of the base in the holding region.
[0012] Optionally, in the intermediate region the base has a join line.
[0013] Optionally, in the intermediate region the base has a void.
[0014] Optionally, in the intermediate region the base has a different material state than it has in the holding region.
[0015] Optionally, in the retaining region the retaining element has a value according to a first geometric dimension that is substantially constant.
[0016] Optionally, in the direction from the first holding area to the second holding area, the intermediate area has successive holding elements with decreasing values according to the first geometric dimension and then increasing values according to the first geometric dimension.
[0017] Optionally, the value according to the first geometric dimension is measured according to a cross section perpendicular to the base, in particular a cross section perpendicular to the base and parallel to the cross section direction.
[0018] Optionally, the value according to the first geometric dimension is measured according to a direction parallel to the base and at a distance from the holding element.
[0019] Optionally, a straight line passes through at least one retaining element and extends through the first and second retaining areas along a direction from the first retaining area towards the second retaining area, said straight line intersecting at least three retaining elements, in particular at least five retaining elements in each of the first and second retaining areas.
[0020] Optionally, any straight line passing through at least one retaining element and extending in a direction from the first retaining area towards the second retaining area while passing through the first and second retaining areas intersects at least one retaining element, in particular at least two retaining elements in the intermediate area, A straight line of the type defined above may intersect a maximum of 70 retaining elements, even 100 retaining elements in each of the first and second retaining areas, and optionally even a maximum of 10 retaining elements, or a maximum of 30 retaining elements in the intermediate area.
[0021] Optionally, the first geometric dimension is a height of the retaining element, measured for each retaining element between a lower end of the retaining element connected to the base and an upper end of the retaining element opposite the lower end.
[0022] Optionally, at least in the holding region, the holding elements are each formed with a rod and a head projecting from and riding on the rod, and at least some of the holding elements in the intermediate region optionally do not include a head.
[0023] Optionally, at least in the retention area, the retention elements are distributed in a regular and repeating pattern.
[0024] Optionally, the holding elements are evenly distributed, for example in rows or columns or in a staggered pattern.
[0025] Optionally, the retaining device further comprises a substrate carrying the base, the substrate optionally comprising a layer of nonwoven material.
[0026] Optionally, the assembly formed by the base and the retaining element has a weight of 10 to 120 g / m 2 , especially 30 to 80 g / m 2 , in some cases 30-70g / m 2 , more specifically 50 to 70 g / m 2 If the assembly includes a substrate, these basis weight values are specifically verified for the assembly including the base and retaining element without the substrate.
[0027] In particular, the base and the retaining element are present in the retaining region and in the intermediate region.
[0028] In particular, the intermediate region continuously connects the two holding regions, with no space between the intermediate region and each of the two holding regions.
[0029] In particular, the first geometric dimension is a dimension along a given direction. As mentioned, this is, for example, the height of the holding element. However, a dimension other than the height can also be used, for example, the width dimension of the holding element measured parallel to the plane of the base. If the holding element has rotational symmetry in at least a portion, the first geometric dimension can be the diameter dimension of these portions. Of course, these dimensions can be combined. Thus, in addition to the first geometric dimension, the holding elements have a second geometric dimension, and the holding elements arranged in the first and second holding regions have a value according to the second geometric dimension that is greater than the value according to the second geometric dimension of the holding elements arranged in the intermediate region.
[0030] In the intermediate region, the retaining elements have geometric properties that are deteriorated relative to the properties of the retaining elements of the retaining region, so that for at least the first geometric dimension the retaining elements of the intermediate region have a lower value.
[0031] However, to a certain extent, the retaining elements of the intermediate region can contribute to the retention force. They make it possible to have fully effective retaining elements over the large areas that the retaining regions constitute, without any interruptions between these fully effective areas. On the other hand, due to their reduced value for the first geometric dimension, the retaining elements of the intermediate region represent a smaller mass than the retaining elements of the retaining regions, which makes it possible to create an effective retention device with a lower basis weight.
[0032] The retention device has increased flexibility in the middle region relative to the retention areas. Thus, for the same number of retention elements, the retention device is not only lighter but also more flexible than a device in which all retention elements do not degrade (i.e., all become two retention areas). This increased flexibility promotes retention quality, for example by allowing the device to better follow the movements of a person wearing an item with such a retention device.
[0033] In particular, in each holding area, the value of the first geometric dimension of the holding element varies within a range determined relative to a maximum value, for example comprised between 80% and 100% of the maximum value, comprised between 85% and 100% of the maximum value, and comprised between 90% and 100% of this maximum value.
[0034] In particular, the maximum value of the first geometric dimension can be substantially the same for the two holding areas, meaning that this maximum value is the same for the two holding areas with a tolerance on the order of 10% or 5%.
[0035] Hereinafter, the "maximum reference value" for a first geometric dimension is the greater of the two maximum values of the first geometric dimension observed for each of the two retention regions. As shown, these two maximum values are typically close together, and therefore the maximum reference value is itself close to each of these two maximum values.
[0036] In the intermediate region, on the other hand, the value of the first geometric dimension can be significantly lower. Thus, for at least some of the retaining elements in the intermediate region, the value of the first geometric dimension can be 30% or less of the maximum reference value, or 50% or less of the maximum reference value, or 60% or less of the maximum reference value. Here, "at least some of the retaining elements in the intermediate region" means at least one retaining element, or at least 10%, or at least 20%, or at least 40% of the retaining elements in the intermediate region.
[0037] However, at least some of the retaining elements in the intermediate region may have a substantial value for the first geometric dimension. Thus, at least some of the retaining elements in the intermediate region may have a value for the first geometric dimension on the order of at least 5%, or at least 10%, or at least 20% of the maximum nominal value. Here, "at least some of the retaining elements in the intermediate region" means at least one retaining element, or at least 10%, or at least 20%, or at least 40% of the retaining elements in the intermediate region.
[0038] According to a second aspect, the present disclosure relates to an absorbent item, such as a baby diaper or an adult incontinence diaper, comprising an assembly including two outer sheets and an absorbent core disposed between the outer sheets, the assembly comprising a front and a side, which are first surfaces of the diaper, the item comprising a hook and loop retention system including receiving loops carried by one of the first surface of the diaper and the side surfaces of the diaper, and at least one retention device of the present disclosure carried by the other of the first surface of the diaper and the side surfaces of the diaper, wherein when at least one of the side surfaces of the diaper is positioned against the first surface, the retention elements cooperate with the receiving loops to retain at least one of the side surfaces of the diaper to the first surface of the diaper.
[0039] The first surface of the diaper is in particular the front surface of the diaper, i.e. the outer surface that faces the lower abdomen of the wearer. The side surfaces of the diaper may be the lateral panels or lugs of the diaper, in particular the elastic lugs.
[0040] By "holding at least one of the sides of the diaper against the first surface," the sides of the diaper are closed against the first surface, preventing them from separating, and / or by holding the sides of the diaper against the first surface, relative displacement between them is prevented and restricted.
[0041] Optionally, the retaining device can be positioned on a surface that includes the loop, such as in an area of the comfort strip (commonly referred to as the landing area), for example near a lateral boundary of the comfort strip.
[0042] According to a third aspect, the present disclosure relates to a method for manufacturing a retention device, comprising: The molding device has a plurality of cavities recessed from a surface, the molding device optionally being a molding strip, an applicator is used to apply heated molding material onto the surface, the molding material penetrates into the cavities to form retaining elements, the manufacturing method generates two separate adjacent streams of molding material and places them in two application areas, the two streams of molding material meet in a confluence area to form a base, and the molding material penetrates further into the cavities in the application areas than into the cavities present in the confluence area.
[0043] Here, "two adjacent streams" means "at least two adjacent streams." It is particularly possible to have three streams, each of which is adjacent to the other, and two confluence areas between the two adjacent streams.
[0044] Optionally, the applicator is an extrusion device including two adjacent channels separated by a partition, and the molding material is applied by moving the molding device and the extrusion device longitudinally relative to one another.
[0045] Optionally, the channels may be of the same section, the section of the channel being considered transversely to the direction of travel of the material within the channel, ie generally along the direction CD.
[0046] There are more than two channels, separated two by respective septa, which can optionally be identical.
[0047] Optionally, the channels can be in different sections.
[0048] Optionally, the partitions can have different geometrical characteristics: in particular, when the number of channels is three or more, it is conceivable that the channels located on the outside in the direction CD have a particularly low section different from the channels located on the inside.
[0049] Optionally, the channels and the partitions separating them can be arranged symmetrically, in particular with respect to a plane defined by the direction MD and a plane perpendicular to the plane defined by the directions MD and CD, this plane of symmetry passing in particular through the middle of the width of the applicator.
[0050] Optionally, a substrate is applied to the plastic material applied to the surface of the molding device before cooling of the molding material, so that the material is sandwiched between the surface of the molding device and the substrate.
[0051] Of course, it is also possible to bring the same molding material, or conversely, different materials, into the different channels.
[0052] In particular, the cavities of the molding device that serve to form the holding elements can all be similar.
[0053] In particular, the cavities of the molding device that serve to form the holding elements can be homogeneously distributed within the molding device (more specifically, on the surface of the molding device intended to receive the molding material). In this case, these cavities are present in the application area and in the confluence area according to the same distribution or density. Due to the spreading of the molding material within the confluence area, the molding material penetrates more into the cavities present in the application area than into the cavities present in the confluence area, so that the holding elements formed in the cavities present in the confluence area are deteriorated compared to the holding elements formed in the cavities present in the application area. Thus, the application area serves to form the holding area of the holding device, while the confluence area is used to form the intermediate area.
[0054] Due to the spreading of the molding material in the confluence area, the molding material can be present in this area at a thinner thickness than in the application area, and as a result, the base of the holding device formed in the confluence area has a thinner thickness than that portion formed in the application area. [Brief explanation of the drawings]
[0055] Other characteristics and advantages of the object of the present disclosure will become apparent from the following description of one embodiment, given by way of non-limiting example, with reference to the accompanying drawings, in which: [Figure 1] 1 shows a schematic representation of an installation for manufacturing a holding device with holding elements. [Figure 2] This is an enlarged view of region II in Figure 1. [Figure 3] FIG. 2 is a schematic cross-sectional view taken along line III-III in FIG. [Figure 4] 4 is a partial schematic view taken along arrows IV and line IV-IV in FIG. 1. [Figure 5] 1 shows an item in cross section with a retaining device according to the present disclosure. [Figure 6] FIG. 6 is a top view of the item of FIG. 5. [Figure 7] FIG. 7 is an enlarged detail of VII in FIG. 5. [Figure 8] FIG. 8 is a partial view of the arrow VIII in FIG. 7. [Figure 9] 1 is a detail of a retaining element of a retaining device according to the present disclosure. [Figure 10] 1 shows an absorbent item including a retention device according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION
[0056] FIG. 1 shows a schematic diagram of an example of an installation for manufacturing a holding device with holding elements.
[0057] The installation shown comprises a molding strip 1 positioned on a rotary drive means 2, here comprising two rolls 21 and 22, and a material distribution means or applicator 3 configured to apply molding material, e.g. a plastic and / or elastic molding material, to the surface of the molding device.
[0058] The forming strip 1 is an example of a forming device.
[0059] This device serves to produce a holding device 5 which is demolded from the moulding device using rolls 6.
[0060] The embodiment may be modified or supplemented by the type described in document WO2017187097 or the one shown in document FR 1914162. The illustrated example with two rolls 21, 22 is not limiting; the number and arrangement of the rolls may be varied, in particular to adapt to the length of the shaped strip 1 and different positions in the device. For example, to form a sleeve or screen, it would be possible to use three rolls or just one roll, with the shaped strip disposed around the periphery of the single roll. In particular, only one of the two rolls, e.g., roll 21, is driven in rotation by a motorized means, while the other roll 22, for example, is driven in rotation by the shaped strip itself, driven by roll 21, without a motorized means.
[0061] A longitudinal direction is defined relative to the direction of travel of the shaped strip 1. This longitudinal direction is commonly called the "machine direction" or MD. The longitudinal direction is indicated in the figures by the axis MD.
[0062] A "cross direction" or CD is also defined, corresponding to a direction perpendicular to the longitudinal direction and extending parallel to the inner and outer surfaces of the shaped strip. In the figures, the cross direction is indicated by the axis CD.
[0063] The moulding strip 1 presented comprises an inner surface 11 and an outer surface 12, the inner surface 11 being in contact with the rotary drive means 2, while the outer surface comprises the surface onto which the moulding material is applied by the applicator 3.
[0064] Specifically, the applicator 3 is positioned opposite the shaping strip 1 and spaced from the shaping strip 1 so as to define a gap e as shown in Figure 1. Mark A marks the limit of the material to be injected onto the outer surface 12 of the shaping strip 1 and corresponds to the back edge of the material to be injected into the shaping strip 1 relative to the displacement direction of the shaping strip 1.
[0065] As can be seen from FIGS. 1 and 4, the molding strip 1 is provided with a number of cavities 13, which allow the production of the holding elements of the holding device 5.
[0066] In this case, the cavities 13 shown in Figure 1 are each formed to serve for the production of a hook-type retaining element, and therefore, as can be better seen in Figure 2, each cavity defines a rod 14 extending from the outer surface 12 towards the inner surface 11 of the molding strip 1, and a head 15 extending between the rod 14 and the inner surface 11 of the molding strip 1.
[0067] In the example shown, the head 15 of the cavity 13 is located on the inner surface 11 of the molding strip 1. The cavity 13 is therefore through-hole. Such an embodiment is not limiting, but the cavity 13 can also be blind and therefore does not emerge from the inner surface 11 of the molding strip 1. Furthermore, the cavity can have a different shape, in particular by lacking a head.
[0068] The portion of the cavity 13 that forms the rod 14 typically extends along a direction perpendicular to the outer surface 12 of the shaped strip 1. The portion of the cavity 13 that forms the rod 14 typically has a shape of revolution about an axis perpendicular to the outer surface 12 of the shaped strip 1 or a shape that extends with plane symmetry along a direction parallel to the direction of movement of the shaped strip 1 and / or a direction perpendicular to the direction of movement of the shaped strip 1.
[0069] The portion of cavity 13 forming rod 14 has, for example, a generally frusto-conical or cylindrical shape rotated about an axis perpendicular to outer surface 12 of shaped strip 1 and rounded at the junction with outer surface 12 of shaped strip 1 .
[0070] The portion of cavity 13 that forms head 15 typically extends radially or transversely to an axis perpendicular to outer surface 12 of formed strip 1 and may have rotational symmetry about this axis perpendicular to outer surface 12 of formed strip 1. The portion of cavity 13 that forms head 15 typically has a frustoconical or hexahedral or substantially frustoconical or hexahedral shape.
[0071] The portion of the cavity 13 forming the head 15 may be straight or curved, for example forming a curved portion towards the inner surface 11 or towards the outer surface 12 of the molding strip 1 extending from the portion of the cavity 13 forming the rod 14.
[0072] The portion of cavity 13 that forms head 15 may have a constant or variable thickness.
[0073] In the example shown in the figure, the portion of cavity 13 forming head 15 extends radially around the portion of cavity 13 forming rod 14 and has the general shape of a disk, as can be seen particularly in Figure 2 presented below.
[0074] The molding strip 1 may have particular texturing on its inner surface 11 or on its outer surface 12, such as slots, a collection of grooves or a collection of passages forming vents or studs, or may be smooth or substantially smooth.
[0075] The shaped strip 1 can be formed by superposition of several strips and is therefore not necessarily of a single piece or material.
[0076] The shaped strip may have a width in the cross direction CD of 5 to 3000 mm.
[0077] The above-described forming device with forming strips is one example of a forming device, other types of devices can be provided, for example, types including plates with forming cavities, which can be moved, for example, in stages.
[0078] Other types of forming devices can also be provided, for example, those that include rolls in which the forming cavities are directly formed. These can be solid rolls, disks machined to provide the forming cavities, or stacked to form a roll, with the forming cavities being formed by machining and / or cutting the edges of the disks, for example, by laser or water jet or by electrical discharge machining, especially wire electrical discharge machining. Of course, the disks can be stacked with alternating solid disks having perfectly circular or cylindrical edges, with disks having notched edges.
[0079] Figure 2 represents the molding material injected into the molding strip 1. Figure 2 represents a (cross-sectional) side view of the material in the cavity 13 of the molding strip 1.
[0080] As can be seen in FIG. 2, the molding material penetrates into the molding strip so as to fill the cavity 13, thus forming the rod and head blank for the retaining element, in this case the hooked retaining element.
[0081] A layer of molding material is also deposited on the outer surface 12 of the molding strip 1 to form a base for the holding device, the thickness of this layer of molding material being determined by the gap e between the outlet of the applicator 3 and the molding strip 1.
[0082] The air gap e typically has a thickness of less than 700 micrometers, or typically from 5 to 500 micrometers, or from 8 to 100 micrometers.
[0083] In the example presented, the cavities 13 of the molding strip 1 are through-holes. The device can then, if necessary, be equipped with an element such as a scraper 4 positioned to scrape the inner surface 11 of the molding strip 1 and remove excess molding material.
[0084] Thus, injection of molding material into molding strip 1 by applicator 3 can form retaining elements in cavities 13, and in this way the device forms tape 100. These can be finished retaining elements or preforms, as described in WO2017187097, which are then subjected to a molding or calendering step for their final shaping. "Injection" here refers to the act of shaping molding material through a melt path, e.g., distributing, feeding, molding, injecting, extruding.
[0085] 3 and 4, the applicator 3 will now be described. The applicator is an extrusion device, in this case comprising at least two adjacent channels separated by a partition. In the example shown, the applicator 3 comprises three aligned channels 3A, 3B and 3C, with channel 3B located between channels 3A and 3C and separated by partitions 3' and 3''.
[0086] For example, the application width L0 of the applicator is between 70% and 100% of the effective width LB of the strip 1. Here, the term "application width" refers to the cross distance measured along the CD direction between the farthest edges of the application channels. It is measured between the outer lateral edge of channel 3A and the opposite outer lateral edge of channel 3C. The three channels 3A, 3B, and 3C in this case have the same width L1, for example, between 1 and 60 mm, possibly between 2 and 50 mm, and in particular between 3 and 30 mm. This width L1 is measured at the outlet of the channel. The partitions 3' and 3'' in this case have the same width L2, for example, between 0.5 and 15 mm, in particular between 0.5 and 10 mm, measured on the outlet face of the applicator. Width L2 is preferably smaller than or equal to width L1.
[0087] The outlets of the channels 3A, 3B, 3C in this case have the form of rectangular openings of width L1 and height e1, the ratio e1 / L1 generally being less than or equal to 2, or even less than or equal to 1, or even, as in the depicted example, less than or equal to 0.5.
[0088] The outlet of the channel can have different shapes, for example, square, round, oval, elliptical, or dog-bone shaped, i.e., roughly rectangular but bulging at the tip by forming one or two lobes.
[0089] 4, channels 3A, 3B, and 3C are shown diagrammatically in plane IV-IV of the molding material advancement, while the molding strip is shown in an external view along arrow IV. At the outlets of the channels, three separate molding material flows 3A, 3B, and 3C are formed. These three flows thus provide molding material to surface 12 of strip 1 in application zones ZA, ZB, and ZC, which are areas of the surface along the channel outlets and in the advancement direction corresponding to direction MD.
[0090] Application of the molding material out of the channels forms a tape of molding material.
[0091] It can be seen that once applied to the channel outlets and / or surface 12, the molding material flows laterally (direction CD). Indeed, once applied to strip 1, the material naturally spreads laterally and tends to fill the space between two adjacent application areas. Due to the small width L2 of the partition walls, adjacent flows naturally merge. Thus, the areas of strip 1 located alongside partition walls 3' and 3'' form confluence areas ZJ, ZJ', where the molding material tapes applied at the outlets of channels 3A, 3B, and 3C tend to meet due to the lateral flow of the molding material. As shown by f in Figure 4, the lateral confluence phenomenon occurs at the channel outlets, at gap e, likely before the molding material contacts surface 12.
[0092] The molding material applied directly in the application zones ZA, ZB and ZC naturally fills the cavities 13 present in these zones through its expansion in the direction MD and under the effect of its velocity component and the outlet pressure of the channel, which is then applied mainly perpendicular to the plane of the surface 12. Meanwhile, in the confluence zones ZJ and ZJ'', this pressure is partially applied to the lateral confluence, and its velocity component is naturally exerted mainly along the direction CD. Due to its lateral expansion, the molding material has difficulty filling the cavities present in the confluence zones. Therefore, the parts of the holding device formed in these confluence zones have deteriorated holding characteristics compared to those of the parts formed in the application zones, while the cavities 13 in the confluence zones and the cavities 13 in the application zones are identical or similar.
[0093] This can be seen in Figure 5, which shows a holding device consisting of a base 51 and a holding element 50 extending from an upper surface 511 of the base 51. In this case, the holding device comprises a substrate 60 on the side of a lower surface 512 of the base 51.
[0094] The upper and lower surfaces 511, 512 of the base are typically parallel or nearly parallel, with the upper surface 511 being the surface with the retaining element 50.
[0095] It can be seen that the device has retention areas RA, RB, RC in which the retention elements are standard. This means that the retention elements present in these retention areas are correctly molded into the cavities. The retention elements in these areas all have substantially the same height h, measured between the top surface 511 of the base 51 and their opposite top ends. This means, in particular, that the heights of these retention elements are all between 80% and 100%, or between 85% and 100%, or even between 90% and 100% of the maximum height observed for these retention elements.
[0096] Here, the geometric dimension considered is the height of the holding element, other geometric dimensions may be considered, for example the thickness of the rods of the holding element measured in a plane parallel to the upper surface of the base, or (if these have heads) the width of the heads of the holding element measured also in a plane parallel to the upper surface of the base.
[0097] Between the retaining areas RA, RB, and RC, the retaining device has intermediate areas RJ and RJ'. It can be seen that the retaining elements 50A present in the intermediate areas RJ and RJ' are deteriorated compared to the others. In particular, their height h' is lower than that of the retaining elements present in the retaining areas, and moreover, these heights probably vary considerably from one retaining element 50A to another. In particular, it can be seen in FIG. 7 that the retaining elements 50A in the intermediate areas RJ and RJ' lack heads, unlike those in the retaining areas RA, RB, and RC.
[0098] Here again, the height is only one of the geometric dimensions of the retaining elements 50A that is taken into account to assess their degradation in comparison with the retaining elements present in the retaining area. Thus, it is understood here that the difference in shape between the retaining elements 50 in the retaining area and the retaining elements 50 in the intermediate area is not due to a different geometric shape of the cavities 13 in the strip 1, but rather to the uneven filling of these cavities with the molding material in the application area and the confluence area.
[0099] FIG. 6 shows the shape of elongated tapes along the direction MD presented by the holding regions RA, RB, and RC, while the intermediate regions RJ and RJ' also have the shape of tapes with a smaller overall width (the width is measured in the direction CD). These intermediate regions have joining lines L and L' corresponding to the confluence of the flows coming from channels 3A and 3B on the one hand, and 3B and 3C on the other. In the intermediate regions, the base has a different material state than that presented in the holding regions. In particular, the base has a uniform molecular orientation along the direction MD within the holding regions. Meanwhile, in the intermediate regions, the molecular orientation changes due to the flow of molding material in a direction with a non-zero component along the direction CD.
[0100] However, it can be seen that these different regions form the same common tape R, with the intermediate region forming the joint between the holding regions.
[0101] As best seen in Figure 6, the retaining elements 50 are distributed in a regularly repeating pattern: they are arranged in columns parallel to the direction CD and in rows parallel to the direction MD, with the retaining elements in adjacent rows and columns being staggered.
[0102] It can also be seen from Figure 4 that the cavities in the molding device are distributed in this regular and repeating pattern.
[0103] In Figures 5 and 7, when considering the intermediate region RJ in the direction from the holding region RA towards the adjacent holding region RB, particularly along the direction CD, it can be seen that the height of the holding element decreases towards the central region of the intermediate region and then increases.
[0104] The base 51 typically has a thickness eb comprised between 3 and 500 micrometers, more particularly between 4 and 150 micrometers, or between 4 and 120 micrometers, or between 4.5 and 108 micrometers.
[0105] In the retention areas RA, RB and RC, the thickness of the base is constant or substantially constant, as measured between two adjacent retention elements 50 of a retention area. By "substantially constant" it is meant that the thickness varies by at most 20%, or even 10%, relative to the average value.
[0106] 5 and 7, the thickness of the base 51 can be thinner in the intermediate regions RJ and RJ', for example, 80%, 60%, or even 50% or less of the average thickness of the base in the holding region.
[0107] As can be seen in Figure 8, the intermediate region RJ, RJ' may even have a void 50B. This is due to a lack of localized joining between the two application areas of molding material, or due to insufficient penetration of the material into the cavity of the molding strip, resulting in the formation of a duct-shaped portion of the retaining element, or due to penetration of the material into the cavity, resulting in a deteriorated retaining element 50A, impairing its lateral expansion and leaving a void at the foot of the deteriorated retaining element. The void 50B has small dimensions. In particular, the maximum dimension of the void, measured as the length of the segment parallel to the upper surface of the base going from one edge of the void to the other, is smaller than the minimum distance between the two retaining elements.
[0108] The base 51 typically has a width comprised between 1 and 3000 millimeters, more particularly between 2 and 400 millimeters, or between 3 and 100 millimeters, the width of the base 51 being measured, for example, along a direction parallel to the outer surface 12 of the forming strip 1, in a direction transverse to the longitudinal direction. This width corresponds to what is called the effective width LB of the strip 1 of the forming device.
[0109] Some of the geometric characteristics of the undegraded retention element 50 (ie, present in the retention area) will now be described with reference to FIG.
[0110] The retaining element in this case has the shape of a hook and comprises a rod 52 and a head 53 projecting laterally from the rod. The total height h of the retaining element 50 can be of the order of 80 to 1000 micrometers, in particular 90 to 500 micrometers, in particular 90 to 450 micrometers. The height h1 of the rod 52, measured from the upper surface of the base 51 to the lower surface of the head 53, can be of the order of 80 to 800 micrometers, in particular 90 to 450 micrometers or 90 to 300 micrometers. The height h2 of the head 53, measured between its lower and upper surfaces, between two planes parallel to the upper surface of the base and tangent to the lower and upper surfaces, can be of the order of 5 to 200 micrometers, in particular 10 to 100 micrometers.
[0111] As shown, the assembly formed by the base and the retaining element has a strength of 10 to 120 g / m 2 , especially 30 to 80 g / m 2 , more specifically 50 to 70 g / m 2 The sheet may have a basis weight of
[0112] The base itself is 5 to 80 g / m 2 , especially 10 to 60 g / m 2 The sheet may have a basis weight of
[0113] The following ratios can be observed in the retention region: Rod height to base height: 0.8~80, especially 1.5~65; Head height to base height: 0.1~30, especially 0.3~22; Height of rod / basis weight of assembly formed by base and holding element: 1 to 10 (unit: micrometer / g / m 2 ).
[0114] The height of the retaining element is measured by the length of a line segment starting from the center of the retaining element, from the height of the upper surface of the base (the average height of this surface as seen on two adjacent retaining elements in the area in question), to the point of intersection with the outer envelope of the hook.
[0115] The base may be formed from the same single material as the retaining element.
[0116] Demolding of the retention device is typically performed when the base is at a temperature below the melting temperature of the molding material or below the temperature at which the molding material will deflect under load, for example when the inner surface 11 of the molding strip 1 is at a temperature on the order of 45°C and the upper surface 511 of the base 51 is at a temperature on the order of 75°C. The deflection temperature under load is commonly referred to as the heat deflection temperature or HDT.
[0117] The molding strip 1 is conventionally maintained in the molding area at a temperature between HDT-30°C and HDT+10°C, in particular between 50°C and 120°C, in particular of the order of 80°C, when the molding material is polypropylene or, in general, an ethylene copolymer.
[0118] Because the base 51 is extremely thin, the temperature of the formed strip in the forming area can be slightly higher than the HDT, since the outer surface of the base (opposite the strip) in contact with the air is at a lower temperature than that of the formed strip, and because of the small thickness of the base, the inner surface of the base and the retaining element cools quickly once the base separates from the formed strip.
[0119] The demolding step can be followed by a molding step in which the second preforms are modified, in particular in the height of their heads 53 .
[0120] As shown, the holding device can include a substrate 60. The substrate is typically a layer of nonwoven material, a plastic film, an elastic or composite film, or a set of heat-consolidated fibers and / or filaments. Substrate 60 can be, for example, a web of fibers and / or filaments.
[0121] "Nonwoven" refers to the product obtained at the end of the formation of a web of consolidated fibers and / or filaments. This consolidation can be mechanical, chemical, or thermal and results in the presence of bonds between the fibers and / or filaments. This consolidation can be direct, i.e., by welding, between the fibers and / or filaments, or indirect, i.e., through an intermediate layer, such as an adhesive or binder layer, between the fibers and / or filaments. The term "nonwoven" refers to a tape-like structure or web of fibers and / or filaments interleaved in a non-uniform, irregular, or random manner. Nonwoven materials can have a single-layer or multi-layer structure. Nonwoven materials can also be bonded to other materials to form laminates. Nonwoven materials can be made from a variety of synthetic and / or natural materials. Typical natural materials are cellulosic fibers, such as cotton, jute, and linen, and can also include reprocessed cellulosic fibers, such as rayon or viscose. Natural fibers for nonwoven materials can be prepared using various methods, such as carding. Exemplary synthetic materials include, but are not limited to, synthetic thermoplastic polymers known to form fibers, including polyolefins such as polyethylene, polypropylene, and polybutylene; polyamides such as polyamide 6, polyamide 6.6, polyamide 10, and polyamide 12; polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polylactic acid; polycarbonate; polystyrene; thermoplastic elastomers; vinyl polymers; polyurethanes; and mixtures and copolymers thereof. For example, the nonwoven material may be a Spunbond, Spunmelt, heatbonded card, SMS, SMMS, SS, SSS, SSMMS, SSMMMS, or Air-through type nonwoven material.
[0122] The substrate is not limited to nonwoven materials, but more generally may be a nonwoven material, a woven material, a knitted material, or some combination of these materials.
[0123] If the substrate 60 is a nonwoven material, it may be activated prior to its fixation to the substrate. The substrate may include several separate layers, particularly a support layer, which may itself be a nonwoven material and optionally activated.
[0124] By "plastic material" is meant a thermoplastic material, more particularly a polyolefin material based on a homopolymer or copolymer.
[0125] The materials described in document WO2017187097 can be used to form the base and the holding element, and, if present, the substrate, which can be added onto the base as described in document WO2017187097.
[0126] The object of the present disclosure is to ensure that the retention device is particularly light, while having excellent retention properties over a possibly substantial width, and is also very flexible, especially in the middle region, which constitutes the whole, and the retention region is continuous with the middle region.
[0127] FIG. 10 shows an absorbent item 200 of the baby diaper or adult incontinence diaper type. Typically, the item 200 comprises an assembly including two outer sheets 210, 220 and an absorbent core 230 disposed between the outer sheets. The item has a diaper first (front) side FA and a diaper side CC. The item comprises a hook-and-loop retention system comprising a receiving loop carried by an element of one of the diaper first side FA and the diaper side CC. In this case, in FIG. 10, a rectangle 240 embodied on the diaper first side FA comprises such a demand loop and corresponds to a comfort strip (generally designated by a landing zone).
[0128] The item also includes a retaining device 5 according to the present disclosure, in this case arranged on each of the side surfaces CC so as to be able to cooperate with a demand loop 240 provided on the front surface FA to keep the item closed when worn by a user.
Claims
1. A base (51) extending along a longitudinal direction (MD) and having an upper surface (511) and a lower surface (512); a plurality of retaining elements (50, 50A) extending from an upper surface of the base, each having a rod (52), each retaining element (50, 50A) having a value according to a first geometric dimension; The holding device has at least two holding areas (RA, RB, RC) and an intermediate area (RJ, RJ') arranged between the two holding areas and connecting the two holding areas, wherein the value according to a first geometric dimension of the holding elements (50) arranged in the first and second holding areas is greater than the value according to a first geometric dimension of the holding element (50A) arranged in the intermediate area, and the ratio of the height of the rod to the basis weight of the assembly formed by the base and the holding elements is 1 to 10 micrometers / g / m ２ A holding device.
2. 2. A retaining device according to claim 1, wherein said retaining areas (RA, RB, RC) and said intermediate areas (RJ, RJ') form an elongated area in the form of a common tape (R).
3. 3. The retaining device according to claim 2, wherein the elongated region and the common tape (R) shape extend along the longitudinal direction (MD).
4. 2. The retaining device according to claim 1, wherein the intermediate region (RJ, RJ') has at least one portion having a base (51) with a thickness that is smaller than the thickness (eb) of the base in the retaining regions (RA, RB, RC).
5. 2. A holding device according to claim 1, comprising a gap (50B) in the base (51) in the intermediate region (RJ, RJ').
6. 2. The retaining device according to claim 1, wherein in the retaining areas (RA, RB, RC) the retaining elements (50) have a first geometric dimension (h) that is substantially constant.
7. 2. The retaining device according to claim 1, wherein in the direction from the first retaining area (RA) to the second retaining area (RB), the intermediate area (RJ) has successive retaining elements (50A) whose values according to the first geometric dimension decrease and then whose values according to the first geometric dimension increase.
8. 2. The holding device of claim 1, wherein a straight line passes through at least one holding element (50, 50A) and extends through the first and second holding areas along a direction from the first holding area (RA) toward the second holding area (RB), the straight line intersecting at least three holding elements in each of the first holding area (RA) and the second holding area (RB).
9. 2. The holding device of claim 1, wherein the first geometric dimension is the height of the holding elements (50, 50A), measured for each holding element between a lower end of the holding element connected to the base (51) and an upper end of the holding element opposite the lower end.
10. 2. A holding device according to claim 1, wherein at least in the holding areas (RA, RB, RC), the holding elements (50) are each formed by a rod (52) and a head (53) projecting from and mounted on the rod.
11. The retaining device of claim 10 , wherein at least some of the retaining elements in the intermediate region are devoid of a head.
12. The assembly formed by the base (51) and the holding element (50, 50A) has a hardness of 10 to 120 g / m ２ The retaining device of claim 1 having a basis weight comprised between
13. The holding device of claim 1 further comprising a substrate (60) supporting said base.
14. The retaining device of claim 13, wherein the substrate (60) comprises a layer of nonwoven material.
15. 1. An absorbent item (200) of the baby diaper or adult incontinence diaper type, the item being a construction comprising two outer sheets (210, 220) and an absorbent core (230) arranged between said outer sheets, the construction comprising a front side which is a first side (FA) of the diaper and side sides (CC) of the diaper, the item comprising a hook-and-loop retention system having receiving loops (240) carried on either the first side of the diaper or one of the side sides of the diaper, and at least one retention device (5) according to claim 1, the at least one retention device (5) being carried on the other of the first side of the diaper and one of the side sides of the diaper, the retention elements cooperating with the receiving loops to retain at least one of the side sides of the diaper to the first side of the diaper when at least one of the side sides of the diaper is placed against the first side of the diaper.
16. 1. A method of manufacturing a retention device, comprising: A forming device (1) having a plurality of cavities (13) extending along a longitudinal direction (MD) and recessed from a surface (12), said forming device optionally comprising a forming strip (1); applying a heated molding material (M) to said surface using an applicator (3), said molding material penetrating into the cavity (13) to form a retaining element; A manufacturing method comprising creating two separate adjacent streams (FA, FB, FC) of said molding material (M) and applying them to two application areas of said surface, said two streams of said molding material meeting at a confluence area to form a base (51), said molding material penetrating said cavity (13) in said application areas further than said cavity in said confluence area.
17. 17. The method according to claim 16, wherein the applicator (3) is an extrusion device comprising two adjacent channels (3A, 3B, 3C) separated by a partition (3', 3''), and the molding material (M) is applied by moving the molding device (1) and the extrusion device (3) relative to each other in the longitudinal direction.
18. 17. The method of claim 16, wherein, before cooling of the molding material (M), a substrate (60) is applied to the plastic material applied to the surface of the molding device (1), so that the molding material is sandwiched between the surface of the molding device and the substrate.