Holding device, absorbent article and method for manufacturing holding device

Abstract

A holding device, an absorbent article and a method for manufacturing a holding device, the holding device comprising: a base extending in a longitudinal direction and having an upper surface and a lower surface, a plurality of holding elements each comprising a rod, the holding elements extending from the upper surface of the base, the holding device has at least two holding regions and an intermediate region which is arranged between the two holding regions and connects the two holding regions, and the holding elements arranged in the first holding region and the second holding region have values according to a first geometric dimension, the value is greater than a value according to a first geometric dimension of the holding element arranged in the intermediate region, and the ratio between the height of the rod and the basis weight of the assembly formed by the base and the holding element is in the range of 1 to 10 microns / g / m.

Description

[0001] This application is a divisional application of the application filed by Eplux, Inc., filed on July 12, 2021, with application number 202180058256.6, entitled “Retaining Device, Absorbent Article Including the Device and Method for Manufacturing the Device”. Technical Field

[0002] This disclosure relates to the field of retainer systems, and more particularly to closure or anti-slip systems. More specifically, this disclosure relates to retainer systems having a retainer element, and more particularly to hook-and-loop retainer systems in which the retainer element can be held in a ring or the like.

[0003] This disclosure also relates to the field of related manufacturing methods and equipment.

[0004] This disclosure also relates to the field of absorbent articles of the type of baby diapers or adult incontinence diapers, said absorbent articles including hook-and-loop retention systems for diapers. Background Technology

[0005] Retention systems, including retention elements supported by a base, are well known and used in many applications, which has led to the production of various forms of retention elements, particularly hooks, designed to mate with each other or with complementary elements such as rings.

[0006] The recurring problem with this product involves the applied holding force, especially when considering the significant reduction in the size of the relevant holding elements and manufacturing constraints.

[0007] In reality, producing high-strength hooks naturally leads to excessively large sizes, which affects the flexibility of the system and thus the user experience. This is extremely disadvantageous in some fields, especially in the hygiene sector, and also leads to increased material consumption, which is unfavorable in terms of cost and manufacturing. The increased material cooling time due to the production of bulky parts actually increases production line downtime.

[0008] Document WO2017187097 discloses a holding device that includes a holding element supported by a base and having specific dimensions and geometric characteristics.

[0009] Therefore, this disclosure aims to solve these various problems by further improving known devices. Summary of the Invention

[0010] According to one aspect of this application, a retaining device is provided, comprising: a base extending in a longitudinal direction and having an upper surface and a lower surface; a plurality of retaining elements, each of the retaining elements including a rod extending from the upper surface of the base; each retaining element having a value according to a first geometric dimension; wherein the retaining device has at least two retaining regions and an intermediate region disposed between and connecting the two retaining regions; the retaining elements disposed in the first and second retaining regions have a value according to the first geometric dimension that is greater than the value according to the first geometric dimension of the retaining element disposed in the intermediate region; wherein the ratio between the height of the rod and the basis weight of the assembly formed by the base and the retaining elements is in the range of 1 to 10 micrometers / g / m².

[0011] According to one embodiment, the holding region and the intermediate region form an elongated region in the form of a band in a common band.

[0012] According to one embodiment, the elongated region and the common strip extend along the longitudinal direction.

[0013] According to one embodiment, the intermediate region has at least one portion in which the thickness of the base is less than the thickness of the base in the holding region.

[0014] According to one embodiment, the base has a gap in the intermediate region.

[0015] According to one embodiment, in the holding region, the holding element has a substantially constant value according to a first geometric dimension.

[0016] According to one embodiment, considering the direction from the first holding region to the second holding region, the intermediate region continuously has holding elements that decrease according to the value of a first geometric dimension, followed by holding elements that increase according to the value of the first geometric dimension.

[0017] According to one embodiment, any straight line passing through at least one retaining element and extending along the direction from the first retaining region to the second retaining region, while passing through both the first and second retaining regions, intersects at least three retaining elements in each of the first and second retaining regions.

[0018] According to one embodiment, the first geometric dimension is the height of the retaining element, and for each retaining element, the height is measured between the lower end of the retaining element connected to the base and the upper end of the retaining element opposite to the lower end.

[0019] According to one embodiment, at least in the retaining area, each of the retaining elements is formed by the rod, the rod covering a head protruding from the rod.

[0020] According to one embodiment, at least a portion of the retaining element in the intermediate region has no head.

[0021] According to one embodiment, the assembly formed by the base and the retaining element has a base weight between 10 g / m² and 120 g / m².

[0022] According to one embodiment, the holding device further includes a substrate that supports the base.

[0023] According to one embodiment, the substrate includes a nonwoven material layer.

[0024] According to another aspect of this application, an absorbent article of the type of baby diaper or adult incontinence diaper is provided, the article comprising an assembly including two outer sheets and an absorbent core disposed between the outer sheets, the assembly being arranged to present a first side and a side of the diaper, the first side being particularly the front surface of the diaper, the article including a hook-and-loop retention system including a receiving ring and at least one retaining device as described above, the receiving ring being carried by one of the side of the diaper and the first side of the diaper, the retaining device being carried by the other of one side of the diaper and the first side of the diaper, such that when at least one side of the diaper is placed against the first side of the diaper, the retaining element cooperates with the receiving ring to retain the at least one side of the diaper relative to the first side.

[0025] According to another aspect of this application, a method for manufacturing a retaining device is provided, wherein: a molding device extending in a longitudinal direction is provided, the molding device having a plurality of cavities formed in a recessed manner from a surface, the molding device optionally including a molding band, and heated molding material is applied to the surface using an applicator by allowing molding material to penetrate into the cavities to form a retaining element, wherein by causing the molding material to flow, the molding material applied to the surface generates two separate adjacent flows in two application areas, such that the two flows meet in a bonding area to form a base, thereby causing the material to penetrate further in the cavities located in the application areas than in the cavities located in the bonding area.

[0026] According to one embodiment, the applicator is an extrusion device comprising two adjacent channels separated by a separator, and the molding material is applied by moving the molding device and the extrusion device relative to each other along the longitudinal direction.

[0027] According to one embodiment, before the molding material cools, a substrate is applied to a plastic material applied to the surface of the molding apparatus, such that the material is sandwiched between the surface of the molding apparatus and the substrate.

[0028] Furthermore, according to other aspects of this application, this disclosure relates to a retainer device, comprising: The base extends longitudinally and has an upper surface and a lower surface. Multiple retaining elements extend from the upper surface of the base, each retaining element having a value according to a first geometric dimension. The retaining device has at least two retainer zones and an intermediate zone disposed between and connecting the two retainer zones. The retaining elements disposed in the first and second retainer zones have a value according to a first geometric dimension that is greater than the value according to the first geometric dimension of the retaining element disposed in the intermediate zone.

[0029] Optionally, the holding area and the intermediate area form an elongated zone in the form of a belt within the common zone, and the elongated zone and the common zone optionally extend along the longitudinal direction.

[0030] Optionally, the intermediate region has at least one portion in which the thickness of the base is less than the thickness of the base in the holding region.

[0031] Optionally, the base has a fusion line in the intermediate zone.

[0032] Optionally, the base may have a gap in the middle section.

[0033] Optionally, in the intermediate zone, the material state of the base differs from that of the base in the holding zone.

[0034] Optionally, in the holding region, the holding element has a substantially constant value according to the first geometric dimension.

[0035] Optionally, considering the direction from the first holding region to the second holding region, the intermediate region continuously has holding elements that decrease according to the value of the first geometric dimension, followed by holding elements that increase according to the value of the first geometric dimension.

[0036] Optionally, the value of the first geometric dimension is measured based on a sectional view perpendicular to the base (in particular a sectional view perpendicular to the base and parallel to the transverse direction).

[0037] Optionally, the value of the first geometric dimension is measured based on a view parallel to the base and at a certain distance from the retaining element.

[0038] Optionally, any straight line passing through at least one retaining element and extending along the direction from the first retaining region to the second retaining region, while passing through both the first and second retaining regions, intersects at least three (particularly at least five) retaining elements in each of the first and second retaining regions.

[0039] Optionally, any straight line passing through at least one retaining element and extending in the direction from the first retaining region to the second retaining region, while simultaneously passing through both the first and second retaining regions, intersects at least one retaining element (particularly at least two retaining elements) in the intermediate region. It may be specified that for any straight line of the above-defined type, it intersects with up to 70 (or even 100) retaining elements in each of the first and second retaining regions, and optionally with up to 10 (or even 30) retaining elements in the intermediate region.

[0040] Optionally, the first geometric dimension is the height of the retaining element, which, for each retaining element, is measured between the lower end of the retaining element connected to the base and the upper end of the retaining element opposite to the lower end.

[0041] Optionally, at least in the holding area, the holding elements are all formed of rods covered with heads protruding from the rods, and at least a portion of the holding elements in the intermediate area may optionally be without heads.

[0042] Optionally, at least in the holding area, the holding elements are distributed in a regular and repeating pattern.

[0043] Optionally, the elements are kept evenly distributed, for example, in rows or columns or in an alternating manner.

[0044] Optionally, the device further includes a substrate supporting the base, the substrate optionally including a layer of nonwoven material.

[0045] Optionally, the assembly formed by the base and retaining element has a basis weight of 10 to 120 g / m², particularly 30 to 80 g / m², in some cases 30 to 70 g / m², and more particularly 50 to 70 g / m². These basis weight values ​​are specifically verified for assemblies that include the base and retaining element but do not have a substrate when the device includes a substrate.

[0046] Specifically, the base and retaining element are located in the retaining area and the intermediate area.

[0047] Specifically, the intermediate zone connects two consecutive holding zones, and there is no space between the intermediate zone and each of the two holding zones.

[0048] Specifically, the first geometric dimension is a dimension along a given direction. As mentioned above, it is, for example, the height of the retaining element. However, it can be a dimension other than height, such as the lateral dimension of the retaining element measured parallel to a plane of the base. When the retaining element has rotational symmetry in at least some parts, the first geometric dimension can be the diameter of those parts. Of course, these dimensions can be combined. Therefore, in addition to the first geometric dimension, the retaining element can have a second geometric dimension for which it has been verified that the retaining element disposed in the first and second retaining regions has a value according to the second geometric dimension that is greater than the value according to the second geometric dimension of the retaining element disposed in the intermediate region.

[0049] The retaining element in the intermediate region has geometric characteristics that are degraded relative to the same characteristics of the retaining element in the retaining region, such that, at least for the first geometric dimension, the retaining element in the intermediate region has a lower value than the retaining element in the retaining region.

[0050] However, to some extent, the retaining elements in the intermediate zone can contribute to the retaining force. They allow for fully effective retaining elements in a large zone consisting of retaining zones without interruption between these fully effective zones. However, due to the reduced value of their first geometric dimension, the retaining elements in this retaining zone exhibit a smaller mass than the retaining elements in the retaining zone, which allows for the production of effective retaining devices with low basis weight.

[0051] The retaining device has increased flexibility relative to the retaining area in one or more intermediate zones. Therefore, for the same number of retaining elements, this device is not only lighter but also more flexible compared to a device in which none of the retaining elements deteriorate (i.e., they are all similar to two retaining areas). This increased flexibility improves the quality of retention, for example, by allowing the device to better follow the movement of a person wearing an item equipped with such a retaining device.

[0052] Specifically, in each holding region, the value of the first geometric dimension of the holding element varies within a defined range relative to the maximum value, for example, between 80% and 100% of the maximum value, or even between 85% and 100% of the maximum value, or even between 90% and 100% of the maximum value.

[0053] In particular, the maximum value of the first geometric dimension can be substantially the same for both holding regions, which means that the maximum value is the same for both holding regions, with a tolerance of about 10% or even 5%.

[0054] In the following text, the “maximum reference value” of the first geometric dimension is the larger of the two maximum values ​​of the first geometric dimension observed for each of the two holding regions. As shown in the figure, these two maximum values ​​are typically close, such that the maximum reference value itself is close to each of the two maximum values.

[0055] On the other hand, in the intermediate region, the value of the first geometric dimension can be quite low. Therefore, for at least a portion of the retaining element in the intermediate region, the value of the first geometric dimension can be less than or equal to 30% of the maximum reference value, or less than or equal to 50% of the maximum reference value, or less than or equal to 60% of the maximum reference value. Here, "at least a portion of the retaining element in the intermediate region" means at least one retaining element in the intermediate region, or at least 10%, at least 20%, or at least 40% of a plurality of retaining elements in the intermediate region.

[0056] However, at least a portion of the retaining element in the intermediate region may have a considerably large value for the first geometric dimension. Therefore, at least a portion of the retaining element in the intermediate region may have a value for the first geometric dimension that is at least 5%, at least 10%, or at least 20% of the maximum reference value. Here, "at least a portion of the retaining element in the intermediate region" means at least one retaining element in the intermediate region, or at least 10%, at least 20%, or at least 40% of a plurality of retaining elements in the intermediate region.

[0057] According to another aspect, this disclosure relates to an absorbent article of the type of infant diaper or adult incontinence diaper, the article comprising an assembly including two outer sheets and an absorbent core disposed between the two outer sheets, the assembly being arranged to present a first side (particularly the front surface) and a side of the diaper, the article including a hook-and-loop retention system comprising a receiving loop carried by one of the side of the diaper and one of the first sides of the diaper (one element), and at least one retaining device according to this disclosure carried by the other of the side of the diaper and the other of the first sides of the diaper (another element), such that when the at least one side of the diaper is placed against the first side of the diaper, the retaining element engages with the receiving loop to retain the at least one side of the diaper relative to the first side.

[0058] The first side of a diaper can be, in particular, the front surface of the diaper, that is, the outer surface located on the lower abdomen of the person wearing it. The sides of the diaper can be side panels or lugs, especially elastic lugs.

[0059] "Retaining at least one side of the diaper relative to the first side" means closing the diaper against the first side by holding them together to prevent them from separating, and / or keeping the diaper against the first side by avoiding or at least limiting their relative slippage.

[0060] Optionally, the retaining device may be arranged on a surface including the ring, for example, in the area of ​​the comfort belt (typically represented by the landing zone, or fastening zone), such as near the lateral boundary of the comfort belt.

[0061] According to another aspect, this disclosure relates to a method for manufacturing a holding device, wherein: A molding apparatus is provided, the molding apparatus having a plurality of cavities formed in a recessed manner from a surface, the molding apparatus optionally being a molding belt. Using an applicator, heated molding material is applied to the surface by allowing the molding material to penetrate into the cavity to form a retaining element. According to this method, by causing the molding material to flow, the molding material applied to the surface generates two separate adjacent flows in two application zones, such that the two flows meet in the bonding zone to form a base, thereby allowing the material to penetrate further in the cavity located in the application zone than in the cavity located in the bonding zone.

[0062] Here, "two adjacent flows" means "at least two adjacent flows". In particular, it is possible to have three pairs of adjacent flows and two junctions, each junction located between two adjacent flows.

[0063] Optionally, the applicator is an extrusion device comprising two adjacent channels separated by a separator, and applies molding material by moving the molding device and the extrusion device relative to each other in the longitudinal direction.

[0064] Optionally, the channels may have the same cross section, which is considered to be transverse to the direction of material movement in the channel, that is, generally considered to be along direction CD.

[0065] There may be more than two channels, which are separated from each other by corresponding separators, which may optionally be the same.

[0066] Optionally, the channel can have different cross-sections.

[0067] Optionally, the separators can have different geometric properties. In particular, when the number of channels is greater than or equal to 3, it is conceivable that the channels located on the outside along direction CD have a different cross-section than the channels located on the inside, especially a lower cross-section than the channels located on the inside.

[0068] Optionally, the channels and the separators separating them may be arranged symmetrically with respect to a plane of symmetry, which is in particular defined by the direction MD and a direction perpendicular to the plane defined by the directions MD and CD, the plane of symmetry passing through the middle of the width of the applicator.

[0069] Optionally, before the molding material cools, the substrate is applied to the plastic material applied to the surface of the molding apparatus, such that the material is sandwiched between the surface of the molding apparatus and the substrate.

[0070] Of course, the same molding material can be introduced into different channels, or conversely, different materials can be introduced into different channels.

[0071] In particular, the cavities of the molding apparatus used to form the retaining element can all be similar.

[0072] Specifically, the cavities of the molding device used to form the retaining element can be uniformly distributed within the molding device (more specifically, uniformly distributed on the surface of the molding device used to receive the molding material). In this case, these cavities exist in the application area and the bonding area with the same distribution or density. Due to creep causing material movement in the bonding area, the material is less likely to penetrate into the cavities in the bonding area compared to the cavities in the application area, resulting in a degraded retaining element from the cavities in the bonding area compared to the retaining element from the cavities in the application area. Therefore, the application area is used to form the retaining area of ​​the retaining device, while the bonding area is used to form the intermediate area.

[0073] Due to creep in the bonding region, the material can exist in the bonding region with a thinner thickness than in the application region, so that the base of the retaining device can have a smaller thickness in its portion from the bonding region than in its portion from the application region. Attached Figure Description

[0074] Other features and advantages of the present disclosure will become apparent from the following description of an embodiment, which is given by way of non-limiting example with reference to the accompanying drawings.

[0075] Figure 1 An example of equipment for producing retaining devices with retaining elements is shown schematically.

[0076] Figure 2 yes Figure 1 Enlarged view of area II.

[0077] Figure 3 It is along Figure 1 A schematic cross-sectional view of line III-III.

[0078] Figure 4 It is based on Figure 1 A schematic partial view of arrow IV and line IV-IV.

[0079] Figure 5 An article including a retaining device according to the present disclosure is shown in cross-section.

[0080] Figure 6 yes Figure 5 A top view of the item.

[0081] Figure 7 yes Figure 5 A magnified view of detail VII.

[0082] Figure 8 It is based on Figure 7 A partial view of arrow VIII.

[0083] Figure 9 Details of the retaining element of the retaining device according to this disclosure.

[0084] Figure 10 An absorbent article including a retaining device according to the present disclosure is shown. Detailed Implementation

[0085] Figure 1 An example of equipment for producing retaining devices with retaining elements is shown schematically.

[0086] The device shown includes: a molding belt 1 positioned on a rotary drive 2, the rotary drive including two rollers 21 and 22; and a material dispensing device or applicator 3 adapted to apply molding material (e.g., plastic and / or elastic molding material) onto the surface of the molding device.

[0087] Molding belt 1 is an example of a molding device.

[0088] This equipment is used to manufacture the retaining device 5, which uses rollers 6 to demold from the molding device.

[0089] In this case, the example shown is of the type described in document WO2017187097; it can be modified or supplemented in particular as indicated in that document or document FR1914162. The example shown, including two rollers 21, 22, is not limiting; the number and arrangement of rollers can be varied specifically to accommodate the length of the molding belt 1 and different positions of the equipment. For example, three rollers or only one roller can be used, such that the molding belt is arranged around the periphery of the single roller to form a sleeve or screen. In particular, only one of the two rollers (e.g., roller 21) can be driven to rotate by a motorized device, while the other roller 22 is free, that is, without a motorized device, and is driven to rotate via the molding belt itself, which is driven by roller 21.

[0090] The longitudinal direction is defined relative to the forward direction of the molding belt 1. This longitudinal direction is often referred to as the "machine direction" or MD. In the accompanying drawings, the longitudinal direction is represented by the axis MD.

[0091] It also defines a "lateral direction" or CD, which corresponds to a direction perpendicular to the longitudinal direction and extends parallel to the inner and outer surfaces of the molding strip. In the accompanying drawings, the lateral direction is represented by the axis CD.

[0092] The molding belt 1 shown includes an inner surface 11 and an outer surface 12, wherein the inner surface 11 is in contact with the rotary drive device 2, and the outer surface has a surface on which molding material is applied by the applicator 3.

[0093] More specifically, the applicator 3 is configured to face the molding belt 1 and be spaced a certain distance from the molding belt 1, thereby confining it within... Figure 1 The air gap e is shown in the figure. Reference numeral A marks the limit of the material injected onto the outer surface 12 of the molding belt 1, corresponding to the rear end face of the material injected onto the molding belt 1 relative to the displacement direction of the molding belt 1.

[0094] like Figure 1 and Figure 4 As shown, the molding belt 1 is provided with multiple cavities 13 to allow the production of the retaining elements of the retaining device 5.

[0095] In this situation, Figure 1 The cavities 13 shown are respectively formed as retaining elements for producing hook shapes. Therefore, as Figure 2 As better shown in the diagram, each cavity defines a rod 14 extending from the outer surface 12 of the molding belt 1 toward the inner surface 11 and a head 15 extending between the rod 14 and the inner surface 11 of the molding belt 1.

[0096] In the example shown, the head 15 of cavity 13 opens out onto the inner surface 11 of molding tape 1. Therefore, cavity 13 is a through cavity. This embodiment is not limiting; cavity 13 can also be blind and therefore not protrude from the inner surface 11 of molding tape 1. Furthermore, the cavity can be of different shapes, particularly without a head.

[0097] The portion of the forming rod 14 of the cavity 13 generally extends along a direction perpendicular to the outer surface 12 of the molding belt 1. The portion of the forming rod 14 of the cavity 13 generally has a geometry that rotates about an axis perpendicular to the outer surface 12 of the molding belt 1, or has a geometry of a plane of symmetry extending along a direction parallel to the travel direction of the molding belt 1 and / or along a direction perpendicular to the travel direction of the molding belt 1.

[0098] The portion of the forming rod 14 of the cavity 13 has a generally truncated conical or cylindrical shape, for example, rotating about an axis perpendicular to the outer surface 12 of the molding belt 1, and has rounded edges at the junction with the outer surface 12 of the molding belt 1.

[0099] The portion of the forming head 15 of the cavity 13 generally extends radially or laterally relative to an axis perpendicular to the outer surface 12 of the molding belt 1, and may have rotational symmetry about this axis perpendicular to the outer surface 12 of the molding belt 1. The portion of the forming head 15 of the cavity 13 generally has a truncated conical or hexahedral shape, or substantially a truncated conical or hexahedral shape.

[0100] The portion of the forming head 15 of the cavity 13 can be linear or curved, for example, forming a portion that extends from the portion of the forming rod 14 of the cavity 13, curves toward the inner surface 11 of the molding belt 1, or curves toward the outer surface 12.

[0101] The portion of cavity 13 forming head 15 can have a constant or variable thickness.

[0102] In the example shown in the figure, a portion of the forming head 15 of the cavity 13 extends radially around a portion of the forming rod 14 of the cavity 13 and has a generally disc-shaped form, as will be presented in particular later. Figure 2 As shown in the image.

[0103] The molded strip 1 may have a specific texture (e.g., slot, groove network, or channel network) on its inner surface 11 or outer surface 12 to form vents or studs, or it may be smooth or substantially smooth.

[0104] The molded strip 1 can be formed by stacking several strips, and therefore does not have to be a single piece or a single material.

[0105] The molded strip along the transverse CD can have a width between 5 mm and 3000 mm.

[0106] The molding apparatus, including the molding belt described above, is an example of a molding apparatus. Other types of apparatus may be provided, for example, those including plates with molding cavities, which are capable of progressive movement, for example.

[0107] Another type of molding apparatus can also be provided, such as those including rollers in which the molding cavity is directly manufactured. These can be solid rollers machined to provide the molding cavity, or stacked discs to form the roller, with the molding cavity formed by machining the edges of the discs and / or by cutting the edges of the discs, for example by laser or water jet or by electrical discharge machining (EDM), particularly wire EDM. Of course, the discs can be stacked by alternating solid discs with perfectly circular or cylindrical edges with discs having slits on the edges.

[0108] Figure 2The molding material injected into the molding belt 1 is shown. Figure 2 A (cross-sectional) side view of the material in the cavity 13 of the molded belt 1 is shown.

[0109] like Figure 2 As shown, molding material penetrates into the molding strip to fill cavity 13, thereby forming a blank for the retaining element, in this case forming a rod and head blank for the retaining element for the hook.

[0110] A molding material layer is also deposited on the outer surface 12 of the molding belt 1 to form a base for holding the device. The thickness of the molding material layer is determined by the air gap e between the outlet of the applicator 3 and the molding belt 1.

[0111] The thickness of the air gap e is typically less than 700 micrometers, or typically between 5 and 500 micrometers, or between 8 and 100 micrometers.

[0112] In the example shown, the cavity 13 of the molding belt 1 is a through cavity. The device may then include elements such as a scraper 4, which is positioned to scrape the inner surface 11 of the molding belt 1 to remove excess molding material if necessary.

[0113] Therefore, injecting molding material into the molding belt 1 via the applicator 3 allows the formation of retaining elements in the cavity 13, thus forming the belt 100. These can be finished retaining elements or preforms that will subsequently undergo forming or calendering steps for their completion, as mentioned in patent application WO2017187097. "Injection" here means the action of shaping molding material through a melt path, such as dispensing, supplying, molding, injection, or extrusion.

[0114] Now refer to Figure 3 and Figure 4 Describe the applicator 3. In this case, the applicator is an extrusion device comprising at least two adjacent channels separated by separators. In the example shown, the applicator 3 includes three aligned channels 3A, 3B, and 3C, with channel 3B located between channels 3A and 3C and separated from the channel by separators 3' and 3''.

[0115] For example, the application width L0 of the applicator is between 70% and 100% of the useful width LB of band 1. Here, the concept of "application width" refers to the lateral distance measured along direction CD between the farthest edges of the application channels. Therefore, it is measured between the outer edge of channel 3A and the opposite outer edge of channel 3C. In this case, the three channels 3A, 3B, and 3C have the same width L1, for example, between 1 and 60 mm, in some cases between 2 mm and 50 mm, and particularly between 3 mm and 30 mm. This width L1 is measured at the channel exit. In this case, the separators 3' and 3'' have the same width L2, which is also measured on the exit surface of the applicator, for example, between 0.5 mm and 15 mm, and particularly between 0.5 mm and 10 mm. Preferably, the width L2 is less than or equal to the width L1.

[0116] In this case, the exits of channels 3A, 3B, and 3C are rectangular openings with a width of L1 and a height of e1. The ratio e1 / L1 is typically less than or equal to 2, or less than or equal to 1, or even less than or equal to 0.5 as in the example shown.

[0117] The exit of the channel can have different shapes, such as square, round, oval, elliptical or dog bone shaped, that is, roughly rectangular, but with a protruding tip by forming one or two lobes.

[0118] exist Figure 4 In the diagram, channels 3A, 3B, and 3C are shown in a schematic cross-section taken in plane IV-IV, in which the molding material advances, while the molding belt is shown in an external view according to arrow IV. It can be seen that three separate molding material flows 3A, 3B, and 3C are formed at the outlet of the channels. Therefore, these three flows apply molding material to three application areas ZA, ZB, and ZC on the surface 12 of belt 1, which are areas of the surface positioned in a straight line with the outlet of the channel along the direction of the molding material's advance in the channel (corresponding to direction MD).

[0119] The molding material applied through the exit channel forms a strip of molding material.

[0120] It can be seen that at the channel outlet and / or once applied to surface 12, the molding material flows laterally (along direction CD). In fact, once applied to band 1, the material naturally tends to diffuse laterally to fill the space between two adjacent application areas. Due to the small width L2 of the separator, adjacent flows will naturally tend to meet. Therefore, the areas of band 1 positioned in a straight line with separators 3' and 3" form joining areas ZJ, ZJ', in which the molding material bands applied at the outlets of channels 3A, 3B, and 3C tend to meet due to the lateral flow of the molding material. Figure 4 As indicated by reference numeral f in the attached figure, lateral creep may occur in the air gap e at the outlet of the channel before the molding material comes into contact with the surface 12.

[0121] The molding material, applied directly to the application zones ZA, ZB, and ZC by advancing along the direction MD, will naturally fill the cavities 13 present in these zones under the action of its velocity component and the outlet pressure of the channel (which is applied primarily to the plane perpendicular to surface 12). On the other hand, in the bonding zones ZJ and ZJ'', this pressure is partially used for lateral creep, and its velocity component is applied naturally and primarily along the direction CD. Due to its lateral diffusion, the molding material is unlikely to fill the cavities present in the bonding zones. Therefore, the retaining elements of the retaining device from these bonding zones are degraded compared to the retaining elements from the application zones, even though the cavities 13 in the bonding and application zones are the same or similar.

[0122] This is Figure 5 As can be seen from the figure, the holding device includes a base 51 and a holding element 50 extending from the upper surface 511 of the base 51. In this case, the holding device also includes a substrate 60 located on the side of the lower surface 512 of the base 51.

[0123] The upper surface 511 and the lower surface 512 of the base are generally parallel or substantially parallel, and the upper surface 511 is the surface on which the retaining element 50 is provided.

[0124] As can be seen, the device has holding regions RA, RB, and RC, where the holding elements are standard. This means that the holding elements present in these holding regions have been molded into the cavity approximately correctly. All the holding elements in these regions have substantially the same height h measured between the upper surface 511 of the base 51 and its opposite upper end. This specifically means that the heights of all these holding elements are between 80% and 100%, or 85% and 100%, or even 90% and 100% of the maximum height observed for these holding elements.

[0125] Here, the geometric dimension considered is the height of the retaining element. Other geometric dimensions may be considered, such as the thickness of the retaining element rod, measured in a plane parallel to the upper surface of the base or between the widths of the retaining element head (if a head is provided), and the thickness of the retaining element rod, measured in a plane parallel to the upper surface of the base.

[0126] Between the holding regions RA, RB, and RC, the holding device has intermediate regions RJ and RJ'. It can be seen that among the holding elements 50, the holding elements 50A present in the intermediate regions RJ and RJ' are degraded compared to the other holding elements. In particular, it can be seen that their height h' is lower than the height of the holding elements present in the holding regions, and these heights can vary considerably even among different holding elements 50A. It can even be seen that, especially... Figure 7 In the middle section, the retaining element 50A of the intermediate RJ and RJ' may be without a head, which is different from the retaining elements in the retaining sections RA, RB and RC.

[0127] Here, height is only one of several geometric dimensions of retaining element 50A, used to assess degradation compared to retaining elements present in the retaining region. Therefore, it should be understood that the shape difference between retaining elements 50 in the retaining region and in the intermediate region is not caused by the different geometries of the cavities 13 of band 1, but by the uneven filling of these cavities by the molding material between the application area and the bonding area.

[0128] Figure 6 The shape of the elongated strips along the direction MD provided by the holding regions RA, RB, and RC is shown, and the intermediate regions RJ and RJ' also have the form of strips that are generally not very wide (width measured along the direction CD). These intermediate regions have weld lines L and L', which correspond on the one hand to the junction of the flow from channels 3A and 3B, and on the other hand to the junction of the flow from channels 3B and 3C. In the intermediate regions, the material state of the substrate may differ from that present in the holding regions. In particular, the substrate may have, for example, a uniform molecular orientation along the MD direction in the holding regions, while in the intermediate regions, the molecular orientation may vary due to the creep of the molding material in the direction having a non-zero component along the direction CD.

[0129] However, it can be seen that these different zones form the same common zone R, and the intermediate zone forms the junction between the zones.

[0130] like Figure 6 As best shown, the retaining elements 50 are distributed in a regular and repeating pattern. Here, they are arranged in rows parallel to direction CD and columns parallel to direction MD, with the retaining elements in adjacent rows and columns arranged in an alternating manner.

[0131] exist Figure 4 It can also be seen that the cavities of the molding device are distributed in this regular and repeating pattern.

[0132] exist Figure 5 and Figure 7As can be seen from the diagram, considering the intermediate region RJ along the direction from the holding region RA to the adjacent holding region RB, especially along the direction CD, the height of the holding element decreases toward the center of the intermediate region and then increases.

[0133] The base 51 typically has a thickness eb between 3 micrometers and 500 micrometers, or more specifically between 4 micrometers and 150 micrometers, or between 4 micrometers and 120 micrometers, or between 4.5 micrometers and 108 micrometers.

[0134] In the holding regions RA, RB, and RC, the thickness of the base is constant or substantially constant. It is measured between two adjacent holding elements 50 in the holding region. "Substantially constant" means that the thickness varies by at most 20%, or even 10%, relative to the average value.

[0135] On the other hand, such as Figure 5 and Figure 7 As shown, the thickness of the base 51 can be reduced in the intermediate regions RJ and RJ'. For example, it can be reduced to 80%, 60%, or even 50% or less of the average thickness of the base in the holding region.

[0136] like Figure 8 As can be seen, it is even possible that the intermediate zones RJ and RJ' may have a gap 50B. This corresponds to a zone where the applied molding material does not locally bond between the two zones due to creep, or the material does not sufficiently penetrate into the cavity of the molding band and forms a conduit-like portion of the retaining element, or the material has penetrated into the cavity to form a deteriorated retaining element 50A, thereby impairing its lateral creep, thus leaving a gap at the bottom of the deteriorated retaining element. The gap 50B typically has a small size. In particular, the maximum size of the gap (i.e., the length of the segment parallel to the upper surface of the base, from one edge of the gap to the other) may be less than the minimum distance between the two retaining elements.

[0137] The base 51 typically has a width between 1 mm and 3000 mm, or more specifically between 2 mm and 400 mm, or between 3 mm and 100 mm. The width of the base 51 is measured relative to the longitudinal direction along the transverse direction, for example, along a direction parallel to the outer surface 12 of the molding belt 1. This width corresponds to the width of the belt 1 of the molding apparatus, referred to as the useful width LB.

[0138] Reference Figure 9 Some geometric characteristics of the undegraded holding element 50 (that is, the holding element existing in the holding region) are described.

[0139] In this configuration, the retaining element has a hook shape, comprising a rod 52 and a head 53 projecting laterally from the rod. The total height h of the retaining element 50 can be approximately 80 to 1000 micrometers, particularly 90 to 500 micrometers, or particularly 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 approximately 80 to 800 micrometers, particularly 90 to 450 micrometers, or 90 to 300 micrometers. The height h2 between the lower and upper surfaces, measured between two planes parallel to the upper surface of the base and tangent to the lower and upper surfaces of the head 53, can be approximately 5 to 200 micrometers, particularly 10 to 100 micrometers.

[0140] As shown in the figure, the base weight of the assembly formed by the base and the retaining element is between 10 and 120 g / m², particularly between 30 and 80 g / m², and even more particularly between 50 and 70 g / m².

[0141] The base weight itself can be between 5 and 80 g / m², especially between 10 and 60 g / m².

[0142] The following ratios can be observed in the retention zone: Pole height to base height: 0.8 to 80, especially 1.5 to 65; Head height to base height: 0.1 to 30, especially 0.3 to 22; The height / base weight of the rod of the assembly formed by the base and retaining elements: 1 to 10 (in micrometers / g / m²).

[0143] The height of the retaining element is measured by the length of a line segment that starts at the center of the retaining element, at the height of the upper surface of the base (the average height of this surface verified between two adjacent retaining elements in the relevant area), and reaches its intersection with the outer envelope of the hook.

[0144] The base can be formed from a single material, which can also be the material that holds the element.

[0145] Demolding of the retaining device is usually carried out when the base is at a temperature below the melting temperature of the molding material or below the load deformation temperature of the molding material, for example when the inner surface 11 of the molding strip 1 is at a temperature of about 45°C and the upper surface 511 of the base 51 is at a temperature of about 75°C. The load deformation temperature is usually referred to as the heat deformation temperature or HDT.

[0146] In the molding zone, the molding band 1 is typically maintained at a temperature between HDT-30°C and HDT+10°C, particularly between 50°C and 120°C, and especially around 80°C, particularly when the molding material is polypropylene or typically an ethylene copolymer.

[0147] Since the base 51 can be extremely thin, the temperature of the molding strip in the molding zone can be slightly higher than the HDT. This is because the outer surface of the base that is in contact with air (opposite to the strip) is at a lower temperature than the strip, and due to the low thickness of the base, the inner surface of the base and the retaining element cool down immediately once the base separates from the molding strip.

[0148] The demolding step may be followed by a molding step, in which the second preform is modified in particular at the height of its head 53.

[0149] As shown in the figure, the holding device may include a substrate 60. This substrate is typically a layer of nonwoven material, a plastic film, an elastic film, or a composite film, or a set of thermosetting fibers and / or filaments. The substrate 60 is, for example, a web of fibers and / or filaments.

[0150] "Nonwoven" refers to the product obtained at the end of the formation of a fabric of already bonded fibers and / or filaments. Bonding can be mechanical, chemical, or thermal, and it results in an adhesion between the fibers and / or filaments. This bonding can be direct, i.e., directly between the fibers and / or filaments by welding, or it can be indirect, i.e., via an intermediate layer (e.g., a glued or adhesive layer) between the fibers and / or filaments. The term "nonwoven" refers to a fabric or strip structure of fibers and / or filaments interwoven in a non-uniform, irregular, or random manner. Nonwoven materials can have a single-layer or multi-layer structure. Nonwoven materials can also be combined with another material to form a laminate. Nonwoven materials can be made from a variety of synthetic and / or natural materials. Exemplary natural materials are cellulose fibers, such as cotton, jute, flax, etc., and may also include reprocessed cellulose fibers, such as rayon or viscose. Natural fibers used in nonwoven materials can be prepared using various methods, such as carding. Exemplary synthetic materials include (but are not limited to) synthetic thermoplastic polymers known for forming fibers, said fibers including (but not limited to): polyolefins, such as polyethylene, polypropylene, polybutene, etc.; polyamides, such as polyamide 6, polyamide 6.6, polyamide 10, polyamide 12, etc.; polyesters, such as polyethylene terephthalate, polybutylene terephthalate, polylactic acid, etc.; polycarbonate; polystyrene; thermoplastic elastomers; vinyl polymers; polyurethanes; and mixtures and copolymers thereof. For example, nonwoven materials can be spunbond fabrics, melt-spun fabrics, thermally bonded carded fabrics, SMS, SMMS, SS, SSS, SSMMS, SSMMMS, breathable nonwoven materials, etc.

[0151] The substrate is not limited to nonwoven materials, but more generally can be nonwoven materials, woven materials, knitted materials, or combinations of these materials.

[0152] If the substrate 60 is a nonwoven material, it can be activated before being fixed to the base. The substrate may include several different layers, particularly a support layer, which may itself be a nonwoven material and may be activated.

[0153] "Plastic materials" refers to thermoplastic materials, and more specifically, to polyolefin materials based on homopolymers or copolymers.

[0154] The materials mentioned in document WO2017187097 can be used to form the base and retain the elements, and to form the substrate (if present). As mentioned in document WO2017187097, the substrate can be added to the base.

[0155] The purpose of this disclosure is to allow for a particularly lightweight retaining device, potentially over a fairly wide area, while possessing excellent retaining properties. Furthermore, it is very flexible, especially in the intermediate zone(s). It forms a single unit, with the retaining area adjacent to the intermediate zone(s).

[0156] Figure 10 An absorbent article 200 of the infant diaper or adult incontinence diaper type is shown. Typically, article 200 includes an assembly comprising two outer sheets 210, 220 and an absorbent core 230 disposed between the two outer sheets. The article has a first side (front surface) FA of the diaper and a side surface CC of the diaper. The article includes a hook-and-loop retention system comprising a receiving loop carried by one of the side surface CC of the diaper and the first side surface FA of the diaper. In this case, in Figure 10 In the first side FA of the diaper, the rectangle 240 includes such a receiving loop and corresponds to the comfort band (usually represented by the landing area).

[0157] The article also includes a retaining device 5 according to the present disclosure. In this case, such a device 5 is provided on each side CC so as to engage with a receiving ring 240 carried thereon by the front surface FA in order to keep the article worn by the user closed.

Claims

1. A holding device, comprising: The base (51) extends along the longitudinal direction (MD) and has an upper surface (511) and a lower surface (512). A plurality of retaining elements (50, 50A), each of the retaining elements (50) including a rod (52), the retaining elements extending from the upper surface of the base, each retaining element having a value according to a first geometric dimension. Its features are: The retaining device has at least two retaining areas (RA, RB, RC) and an intermediate area (RJ, RJ') disposed between and connecting the two retaining areas. The retaining element (50) disposed in the first and second retaining areas has a value according to a first geometric dimension (h), which is greater than the value according to the first geometric dimension of the retaining element (50A) disposed in the intermediate area. The ratio between the height of the rod and the base weight of the assembly formed by the base and the retaining element is in the range of 1 to 10 micrometers / g / m².

2. The holding device according to claim 1, wherein, The holding regions (RA, RB, RC) and the intermediate regions (RJ, RJ') form an elongated region in the form of a band in the common zone (R).

3. The holding device according to claim 2, wherein, The elongated region and the common band extend along the longitudinal direction (MD).

4. The holding device according to claim 1, wherein, The intermediate region (RJ, RJ') has at least one portion in which the base (51) has a thickness less than the thickness (eb) of the base in the holding region (RA, RB, RC).

5. The holding device according to claim 1, wherein, In the intermediate area (RJ, RJ'), the base (51) has a gap (50B).

6. The holding device according to claim 1, wherein, In the holding regions (RA, RB, RC), the holding element (51) has a substantially constant value according to the first geometric dimension (h).

7. The holding device according to claim 1, wherein, Considering the direction from the first holding region (RA) to the second holding region (RB), the intermediate region (RJ) continuously has holding elements (50A) that decrease according to the value of the first geometric dimension, followed by holding elements that increase according to the value of the first geometric dimension.

8. The holding device according to claim 1, wherein, Any straight line that passes through at least one retaining element (50, 50A) and extends along the direction from the first retaining area (RA) to the second retaining area (RB) while passing through both the first and second retaining areas intersects at least three retaining elements in each of the first and second retaining areas.

9. The holding device according to claim 1, wherein, The first geometric dimension is the height of the retaining element (50, 50A), and for each retaining element, the height is measured between the lower end of the retaining element connected to the base (51) and the upper end of the retaining element opposite to the lower end.

10. The holding device according to claim 1, wherein, At least in the holding areas (RA, RB, RC), each of the holding elements (50) is formed by the rod (52) which covers a head (53) protruding from the rod.

11. The holding device according to claim 10, wherein, At least a portion of the retaining element in the intermediate region has no head.

12. The holding device according to claim 1, wherein, The assembly formed by the base (51) and the retaining elements (50, 50A) has a base weight between 10 g / m² and 120 g / m².

13. The holding device according to claim 1, further comprising a substrate (60) supporting the base.

14. The holding device according to claim 13, wherein, The substrate includes a nonwoven material layer.

15. An absorbent article (200) of the type of baby diaper or adult incontinence diaper, the article comprising an assembly including two outer sheets (210, 220) and an absorbent core (230) disposed between the outer sheets, the assembly being arranged to present a first side (FA) and a side (CC) of the diaper, the first side being particularly the front surface of the diaper, the article including a hook-and-loop retention system including a receiving ring (240) and at least one retention device (5) according to claim 1, the receiving ring being carried by one of the side of the diaper and the first side of the diaper, the retention device being carried by the other of one side of the diaper and the first side of the diaper, such that when at least one side of the diaper is placed against the first side of the diaper, the retention element cooperates with the receiving ring to retain the at least one side of the diaper relative to the first side.

16. A method for manufacturing a retaining device, wherein: A molding device (1) extending in a longitudinal direction (MD) is provided, the molding device (1) having a plurality of cavities (13) formed in a recessed manner from a surface (12), the molding device optionally including a molding strip (1). Using an applicator (3), heated molding material (M) is applied to the surface to form a retaining element by allowing the molding material to penetrate into the cavity (13). The feature is that by causing the molding material to flow, the molding material (M) applied to the surface (12) generates two separate adjacent flows in two application areas, such that the two flows meet in the bonding area to form a base (51), thereby allowing the material to penetrate further in the cavity located in the application area than in the cavity located in the bonding area.

17. The method according to claim 16, wherein, The applicator (3) is an extrusion device comprising two adjacent channels separated by separators (3', 3''), and applies the molding material (M) by moving the molding device (1) and the extrusion device (3) relative to each other in the longitudinal direction.

18. The method according to claim 16, wherein, Before the molding material (M) cools, a substrate (60) is applied to the plastic material applied to the surface of the molding apparatus (1), such that the material is sandwiched between the surface of the molding apparatus and the substrate.

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