METHOD FOR JOINING AN ABSORBENT ARTICLE AND A CONTINUOUS STRIP

Abstract

The invention relates to a method for joining an absorbent article and a continuous strip. The method comprises a step of bonding a section of a moisture sensor strip to a first partial surface of the absorbent article, wherein no bonding of the moisture sensor strip to the first partial surface occurs in a pocket region of the absorbent article. A section of a cover layer is bonded to a second partial surface of the absorbent article, wherein, in the pocket region, lateral edge regions of the cover layer are bonded to the absorbent article, while an area between the lateral edge regions remains free of adhesive. The cover layer overlaps both longitudinal edges of the moisture sensor strip. The bonded section of the moisture sensor strip and the bonded section of the cover layer are separated from the continuous strip.An access opening to a pocket space is provided, which is accessible via the access opening that is bounded by the pocket area of ​​the absorbent article, by the lateral edge regions of the cover layer, and by the area between the lateral edge regions. The invention further relates to an endless roll of a continuous strip for use in the inventive method, a device for use in the inventive method, and a system produced in the inventive method.

Description

[0001] The invention relates to a method for bonding an absorbent article and a continuous strip comprising a moisture sensing strip and a cover layer. It further relates to an endless roll of a continuous strip for use in the method according to the invention, an apparatus for use in the method according to the invention, and a system produced by the method according to the invention.

[0002] One of the greatest challenges facing modern societies in the coming years is the aging of their populations. The number of nursing staff and elderly people in nursing homes will become increasingly unbalanced, meaning fewer nursing staff will be caring for more residents, which will create various difficulties.

[0003] Today, nurses already monitor residents on a tight schedule, which not only creates a demanding workload but also makes it difficult to determine which urgent matters need to be addressed first. Furthermore, nurses must monitor a certain number of residents per shift, making efficient scheduling even more important.

[0004] In home care situations, family caregivers also face similar challenges and must care for a dependent in addition to their other responsibilities such as work, other family members, and other obligations, placing them under considerable time pressure and exposure to a high level of stress. For private households and parents or caregivers, baby care is also a time-consuming task.

[0005] There are two circumstances, among others, that justify the need for absorbent items. First, incontinence, which can be understood as a condition that can have many different causes, and the circumstance in the area of ​​infant care, which is related to the child's lack of independent control over their excretions.

[0006] Incontinence is a condition involving the uncontrolled discharge of natural waste from the bladder and / or bowel. Urinary incontinence is defined as the loss of bladder control, resulting in involuntary or uncontrolled urination. While some forms of incontinence, particularly urinary / bladder incontinence, are relatively common, the condition typically affects older and frail people and is more common in women.

[0007] Another current pain point in nursing homes is night shifts. One of the biggest challenges is that the nursing home is spread out and fewer nursing staff are available during these shifts. Therefore, the physical strain on nursing staff becomes a problem.

[0008] In addition, due to the shortage of nursing staff, it is often the case that nurses have to fill in for others or are temporarily hired from outside sources. In such cases, it is important to ensure a quick onboarding and thus a smooth integration into the nursing home's workflow.

[0009] It is therefore an object of the present disclosure to overcome or mitigate at least some of the disadvantages of the prior art and to provide a method for producing absorbent articles comprising a sensor that enables automatic detection of moisture in the absorbent article. In this context, the article should be characterized by ease of handling.

[0010] The stated object is achieved by the subject matter of the independent claims. Advantageous embodiments of the invention are further disclosed in the dependent claims.

[0011] A first aspect of the disclosure relates to a method for bonding an absorbent article and a continuous strip comprising a moisture sensor strip and a cover layer. The method (basic embodiment) comprises a step of bonding a portion of the moisture sensor strip to a first partial surface of the absorbent article by applying a first adhesive between the moisture sensor strip and the first partial surface, wherein no bonding of the moisture sensor strip to the first partial surface occurs in a pocket region of the absorbent article.A further method step comprises bonding a portion of the cover layer to a second partial surface of the absorbent article by applying a second adhesive between the cover layer and the second partial surface, wherein, in the pocket region of the absorbent article, lateral edge regions of the cover layer are bonded to the absorbent article, while an area between the lateral edge regions remains free of adhesive, and wherein the cover layer overlaps both longitudinal edges of the moisture sensor strip. In a further step, the bonded portion of the moisture sensor strip and the bonded portion of the cover layer are separated from the continuous strip.Furthermore, an access opening to a pocket space is provided which is delimited by the pocket region of the absorbent article, by the lateral edge regions of the cover layer and by the region between the lateral edge regions, wherein the pocket space is accessible via the access opening.

[0012] A method is provided for converting an absorbent article into an absorbent article containing a sensor suitable for measuring moisture, which can be done either during the production process of the absorbent article or after the absorbent article has been manufactured.

[0013] Dielectric spectroscopy is preferably used as a suitable measurement method. This method allows the magnitude and phase shift between the applied sinusoidal voltage and the measured current to be observed. This method enables the separation of conductive (real) and capacitive (imaginary) components of the impedance; moreover, a 4-wire measurement increases the accuracy of the impedance measurements. The product manufactured using the method according to the invention is therefore suitable for moisture measurement using the aforementioned method. Accordingly, the advantages mentioned below, which influence the properties within a measurement method due to the design, always refer to the aforementioned measurement method.

[0014] Absorbent articles include hygiene and sanitary products, such as (disposable) diapers, sanitary pads, panty liners, incontinence pads, and sweat towels. These can be used by humans as well as animals, such as pets. The absorbent article absorbs the fluid released by the wearer, e.g., liquid excretions and bodily fluids. Absorbent articles as incontinence products represent a particularly broad field of application, particularly in the form of diapers for adults and children. Absorbent articles include, in particular, precursors that are processed into a final product in subsequent process steps.

[0015] The continuous strip comprises a strip characterized by its ability to be quasi-infinite. Of course, it is not mathematically infinite. For practical purposes, quasi-infinite means that it can be used multiple times in the process at hand. In other words, the process can be run multiple times. It consists of repeating components, so that with each run of the process, the elements required for the process are provided by the continuous strip, without the continuous strip being consumed after the process is applied. Instead, it can be reused to repeat the process to produce the process product.

[0016] The humidity sensor strip consists of a strip suitable for measuring humidity. For the present method, this means that the sensor comprises at least the components that initially detect the measurement signal. This can generally be referred to as a measuring sensor, although this does not mean a sensor in the literal sense. In other words, it refers to the measuring instrument that detects the desired measured variable using the underlying measurement method. In addition, the sensor can also contain other components, such as those for processing the measurement signal.

[0017] The cover layer consists of a strip that forms an outer layer and acts as a shielding layer, further minimizing external interference during the measurement process and further increasing wearer comfort. It also protects the moisture sensor strip by covering it. For reasons of wearer comfort, the cover layer should preferably be breathable; in particular, the cover layer should not have hydrophilic properties so as to minimize interference with the measurement process. In particular, this prevents the measurement from being distorted during a capacitance measurement. Furthermore, the cover layer is preferably thick enough to shield the sensor located underneath. This means that external influences, such as pressure against the inner thigh, do not lead to an increase in capacitance. An appropriately designed thickness also ensures sufficient tensile strength, which simplifies processing in production lines.

[0018] The term "strip," which is used for both the continuous strip and the cover layer, is by no means tied to a specific shape. Therefore, various shapes are possible. For example, the shape of the humidity sensor strip can be rectangular, square, circular, elliptical, and more. The same applies to the cover layer.

[0019] The first adhesive and the second adhesive comprise those types and types of adhesives suitable for bonding the respective elements according to the present inventive method. Accordingly, the first adhesive and the second adhesive may differ from each other. Furthermore, the first adhesive and the second adhesive may also consist of the same adhesive.

[0020] The use of the first adhesive fixes the moisture sensor strip in place and also ensures a uniform distance between the sensor surface and the absorbent article. Depending on the measurement method, this increases measurement accuracy by preventing movement or positioning by the user, etc. In particular, it reduces capacitance variation between different absorbent articles bonded to the continuous strip. The first adhesive and the second adhesive also provide better insulation against liquid. The first adhesive and the second adhesive should each be compatible with the surfaces to which they are applied. Preferably, they have low surface energies.

[0021] The thickness of the applied first adhesive is selected to isolate the moisture sensor strip from the absorbent article and reliably bond it to it. Furthermore, the thickness is selected to reduce the penetration depth of the moisture sensor strip when using the appropriate measurement method. The adhesive is preferably homogeneous to reduce fluctuations in the measured values ​​of different absorbent articles or uneven effects caused by swelling of the core of the absorbent article, which lead to high variance in the measured values.

[0022] The first partial area and the second partial area of ​​the absorbent article have different shapes and preferably have shapes that correspond to the section of the moisture sensor strip and the section of the cover layer, respectively. In particular, the second partial area can encompass the first partial area.

[0023] In the area of ​​the pocket space, there is no first adhesive between the moisture sensor strip and the first partial surface of the absorbent article, so that a contact element for a conductive connection of further hardware components can be detachably connected to electrodes of the moisture sensor strip through the pocket space.

[0024] Using the method, any absorbent article can be easily converted into an absorbent article with a moisture measurement device or into an absorbent article suitable for moisture measurement, without having to modify the essential materials or components of the absorbent article. A production line for absorbent articles can be modified so that the method according to the invention can be integrated into the process for manufacturing the absorbent article. Alternatively, the method according to the invention can also be applied to an existing absorbent article after its manufacturing process.

[0025] In a preferred embodiment of the basic embodiment of the present disclosure, the pocket space is configured to receive a clip comprising an integrated circuit, a first pivotable element, and a second pivotable element connected to the first pivotable element at a folded edge, wherein a size of the pocket space is adapted to the size of the first pivotable element. Furthermore, the pocket space is configured to be pierced by teeth of the second pivotable element in a closed position of the clip to secure the clip to the cover layer. Furthermore, the pocket space is configured to align the clip with the humidity sensor strip such that contact surfaces of the humidity sensor strip and contact pins of the clip are conductively connected to each other and that the humidity sensor strip is aligned between the teeth.In other words, a suitable clip has two pivoting parts. The first pivoting element is inserted into the pocket space, the second pivoting element is used to be attached to the pocket space and to establish contact between the clip and the sensor. The teeth of the clip penetrate the cover layer and hold it in position. Due to the pocket space designed according to the invention, this is configured to be narrow enough to align the clip with the moisture sensor strip. At the same time, the pocket space is dimensioned so that the contact pins can be correctly and easily aligned with the contact surfaces, such as circumferential tracks of interdigitated electrodes, while at the same time the clip is securely held in place. Accordingly, the material of the cover layer is selected so that the basis weight is low enough for the teeth to pierce the pocket space and the clip to remain in place.The clip clamps the humidity sensor strip between the clip's contact pins and the flexible parts of the closure hinge. This applies pressure to the back of the humidity sensor strip, forcing it against the contact pins.

[0026] Preferably, the method involves forming a plurality of identical pocket sections with a plurality of corresponding lateral edge regions of the cover layer and a plurality of regions between the lateral edge regions, so that a corresponding plurality of pocket spaces defined by them is also formed. In this way, it is possible to have pocket spaces at different locations and thus have the option of attaching a clip with hardware at any location.

[0027] In a first preferred embodiment (so-called roll-to-roll method) of the present disclosure, the continuous strip is provided as an endless roll comprising the moisture sensor strip adhered to the cover layer, and wherein a portion of the continuous strip comprising the portion of the moisture sensor strip and the portion of the cover layer is unrolled before being adhered to the absorbent article. Accordingly, the moisture sensor strip and the cover layer are not used separately in the present method, but rather as a type of semi-finished product, i.e., prefabricated raw material, or even as a type of laminate of the two aforementioned components. The moisture sensor strip and the cover layer are also adhered to one another according to the relative arrangement according to the invention.This significantly simplifies the application of the two components and simultaneously increases their precision. Since they are already bonded together, the two components can no longer slip relative to each other. Therefore, it is not necessary to simultaneously ensure the correct positioning of the moisture sensor strip relative to the absorbent article, the cover layer relative to the absorbent article, and the moisture sensor strip relative to the cover layer. Instead, it is only necessary to ensure the correct positioning of the bonded component, consisting of the moisture sensor strip section and the cover layer section, relative to the absorbent article. Furthermore, this control is performed continuously and section by section due to the unwinding process.Even after applying the section of the moisture sensor strip and the section of the cover layer to the absorbent article, both components can no longer slip or shift, but remain in their arrangement.

[0028] According to a second preferred embodiment (also called a roll-to-roll process) of the invention, the moisture sensor strip is provided as a first endless roll and the cover layer as a second endless roll. This offers flexibility during the process. By providing the moisture sensor strip and the cover layer in the form of a first endless roll and a second endless roll, it is possible for the cover layer to cover not only the longitudinal edges of the moisture sensor strip but also the transverse edges after the moisture sensor strip has been applied from the first endless roll to the absorbent article. As a result, the moisture sensor strip is completely covered by the cover layer and is overlapped on all sides, which offers it additional protection. Furthermore, the provision of two rolls allows for interchangeability of the rolls.Depending on the application, different requirements may be placed on the moisture sensor strip or the cover layer. By providing both separately, a suitable moisture sensor strip or cover layer can be selected depending on the application, which proves to be particularly suitable for the absorbent article. This also ensures that the cover layer is adapted to the moisture sensor strip.

[0029] A first variant of the second preferred embodiment of the method comprises, before bonding the section of the moisture sensor strip to the first partial surface of the absorbent article and before bonding the section of the cover layer to the second partial surface of the absorbent article, the step of bonding the moisture sensor strip to the cover layer by applying a third adhesive between at least a portion of the moisture sensor strip and a portion of the cover layer. This results in a combination of the advantage of increased precision in the arrangement of the moisture sensor strip and the cover layer relative to each other and to the absorbent article, and the advantage of increased flexibility, since the moisture sensor strip and the cover layer used are advantageously matched to one another.

[0030] According to a second variant of the second preferred embodiment of the invention, after bonding the portion of the moisture sensor strip to the first partial surface of the absorbent article, the method further comprises the step of bonding the moisture sensor strip to the cover layer by applying a third adhesive between the moisture sensor strip and the cover layer. In this case, the moisture sensor strip is placed on the absorbent article and already secured by the fabric fastener before the cover layer is bonded to the moisture sensor strip and the absorbent article. In this way, the user of the method can select and control at any time whether and to what extent the cover layer overlaps the moisture sensor strip at the transverse edges, while simultaneously ensuring that the moisture sensor strip is secured and does not slip when the cover layer is applied.

[0031] In a further preferred embodiment of the second variant of the second preferred embodiment, the moisture sensor strip in the pocket area of ​​the absorbent article remains free of adhesive in the area between the lateral edge regions. Accordingly, the moisture sensor strip is freely movable in the pocket area. This prevents a glued moisture sensor strip in the pocket area from being improperly connected to any hardware that may be electrically connected to the moisture sensor strip. This free mobility allows it to be aligned as desired, and tolerance-related inaccuracies can be compensated for.

[0032] In a further preferred embodiment of the first preferred embodiment or the first variant of the second preferred embodiment, the moisture sensor strip is intermittently bonded to the cover layer, with a non-bonded region of the moisture sensor strip being overlaid before the moisture sensor strip is bonded to the pocket region. This combines the advantage that the moisture sensor strip and cover layer are bonded together before bonding to the absorbent article with the advantage that the moisture sensor strip remains adhesive-free and thus mobile in a pocket region.

[0033] According to a third preferred embodiment (so-called retrofit), the endless roll further comprises the first adhesive, the second adhesive, and at least one release paper for covering the first adhesive and the second adhesive, and wherein the method further comprises the step of removing the release paper after unwinding the portion of the continuous strip and before adhering the portion of the moisture sensor strip and / or before adhering the portion of the cover layer to the absorbent article. This further simplifies the application of the portion of the moisture sensor strip and the portion of the cover layer to the absorbent article. The first adhesive and the second adhesive are already present for adhering and do not need to be applied additionally. Furthermore, no adhesive needs to be applied to the absorbent article.This requires a high degree of precision to avoid the presence of excess adhesive, which would either have to be removed or would compromise the backing. Furthermore, the adhesive is easily exposed by removing the release liner. Furthermore, complicated additional equipment for applying the adhesives is eliminated, allowing a wider range of people, particularly in healthcare facilities, to bond the moisture sensing strip and the topsheet section to the absorbent article.

[0034] A preferred embodiment of the third preferred embodiment further comprises the step of winding the removed release paper onto a release paper roll and applying pressure to the continuous strip portion with a pressure roller while adhering the moisture sensing strip portion and the topsheet portion to the absorbent article, wherein the continuous roll and the release paper roll are connected by a gear with a clutch. The connection between the continuous roll and the release paper roll exerts permanent tension on the continuous strip portion, so that the unwinding of the continuous strip portion is uninterrupted.By applying pressure to the continuous strip section with the pressure roller when bonding the moisture sensor strip section and the top layer section to the absorbent article, a reliable bond is created between the moisture sensor strip section and the top layer section and the absorbent article. Furthermore, the unwound release liner is automatically rolled up, so it doesn't interfere with the user.

[0035] In the third preferred embodiment, the pressure of the pressure roller is preferably adjusted by spring preload. This allows the static pressure provided by the pressure roller to be varied and adjusted at any time. This is particularly necessary for absorbent articles of varying thicknesses. In these cases, it is advantageous to adjust the contact pressure to always ensure the contact pressure required for secure bonding.

[0036] In a preferred method according to the third preferred embodiment, the pressure is exerted by a first pressure roller and a second pressure roller, which form a gap into which the absorbent article is inserted to bond the portion of the moisture sensor strip and the portion of the cover layer to the absorbent article. This further reduces application errors. The first pressure roller and the second pressure roller and the gap formed between them form a guide, which, on the one hand, exerts a suitable contact pressure and, on the other hand, forms a guide that makes it easier for the user to correctly bond the portion of the moisture sensor strip and the portion of the cover layer to the absorbent article.

[0037] In a preferred embodiment of the third preferred embodiment, one end of the section of the continuous strip is arranged in front of the first pressure roller and the second pressure roller, and the absorbent article receives the end when the section of the continuous strip is inserted into the nip. This further facilitates the application of the method for the user. The release paper is already unrolled so that the absorbent article comes into contact with the exposed first adhesive and / or second adhesive. As a result, the section of the continuous strip adheres to the absorbent article and gradually adheres to the absorbent article as the absorbent article is inserted. In other words, the user only needs to insert the absorbent article into the nip. The arrangement of the section of the continuous strip on the absorbent article and the adhesion to one another occur automatically.The removal of the release paper from the section of the continuous strip and the rolling up also take place automatically.

[0038] Another aspect of the present disclosure relates to an endless roll (basic embodiment) of a continuous strip for use in any of the methods according to the basic embodiment, the first preferred embodiment and the third preferred embodiment of the invention or a preferred embodiment of the foregoing, wherein the endless roll comprises a humidity sensor strip comprising two interdigitated electrodes (IDE) printed with ink based on conductive materials on a polymer substrate, preferably polyethylene terephthalate (PET) substrate, a cover layer comprising a nonwoven material and an access opening to a pocket space, and a third adhesive disposed at least intermittently between a first surface of the humidity sensor strip and a first surface of the cover layer material, wherein no third adhesive is disposed in the pocket space.After a section of the continuous strip is connected to an absorbent article and optionally connected to a sensor clip comprising further hardware, for example, an integrated circuit for the aforementioned dielectric spectroscopy, a moisture / fill level of the absorbent article can preferably be determined based on a capacitance determination via the IDE, wherein the capacitance depends on wetting of an absorbent core of the absorbent article and a concomitant change in its dielectric permittivity. The IDE provides a suitable field penetration depth for measuring the dielectric properties of the absorbent core, but not of a wearer's body. The two interlocking conductive regions are separated from each other and electrically insulated.The interlocking structure of the sensor creates a fringe field with a limited range, the penetration depth, that interacts with dielectric materials within the penetration depth. The interlocking electrode is printed on the surface of the PET substrate. When in contact with a suitable clip, this allows impedance measurements along the entire length of the moisture sensor strip and the determination of capacitance values ​​for the absorbent article. This allows the fill level of the absorbent article to be determined using a suitable calculation algorithm. Furthermore, the section of the moisture sensor strip is only capacitively coupled to the absorbent material, i.e., without electrical contact. Wetting the absorbent core with an aqueous solution changes the dielectric constant / permittivity of the absorbent core, resulting in a measurable change in capacitance.Due to the interlocking structure, the sensor has a maximum penetration depth of approximately 5 millimeters, which is sufficient to measure the dielectric properties of the absorbent core, but not the body of the absorbent article wearer. The moisture sensor strip consists of a flexible and flat PET substrate, allowing the product to be attached to the exterior of an absorbent article and conform to its shape during manufacturing, folding, packaging, unpacking, and wear by the user / patient. The IDE is preferably produced using a roll-to-roll screen printing process, but other processes such as flexographic printing or (rotary) gravure printing are also possible.

[0039] The conductive-based ink preferably comprises printable conductive materials, in particular conductive carbon materials (particles) in a polymer binder, conductive polymers, copper, and / or silver. In particular, conductive carbon materials (particles) in a polymer binder make the IDE flexible and allow measurements to be taken while the user / patient is wearing the absorbent article, regardless of their movement position. Carbon is an abundant and inexpensive raw material. The particles are held together in the printing paste by a non-conductive binder. No sintering of the particles occurs. The costs are competitive compared to metal pastes, and the particles have a smaller ecological footprint.

[0040] The color imprint can be produced using additive manufacturing processes such as rotary screen printing, flexographic printing, or gravure printing. These processes are highly repeatable, fast, and cost-effective, and can be used roll-to-roll. The carbon-based ink has high scratch resistance and low electrical contact resistance, allowing the contact pins of a clip to be easily connected to the sensor. The carbon layer is oxidation-resistant under standard conditions, meaning no topcoat is required, as with etched copper-clad laminates (FlexPCBs) or printed copper or silver traces, and the contact points do not need to be coated (e.g., with gold).The cured carbon-based ink is stable when bent at the bending diameters expected in the production of absorbent articles, so that no significant reduction in conductivity occurs, which has been measured up to a bending diameter of 8 mm.

[0041] PET is inexpensive, flexible, and non-stretchable. It can be cured at temperatures up to 130°C, allowing for rapid curing of the conductive ink. PET can be heat-treated to prevent substrate shrinkage during ink curing, and the surface can be modified to improve printability and substrate adhesion. PET also has high chemical resistance, for example, to organic solvents commonly used in conductive screen printing pastes. Printing on a flat substrate such as PET film also has the advantage of better conductivity, as the ink does not penetrate the porous structure, and better structural stability, as flexing of porous substrates can deform the impregnated conductor tracks.

[0042] The design of the IDE is optimized so that the penetration depth of the generated electric field does not exceed 5 mm for impedance measurements, meaning that any change in the capacitance value can be attributed to the presence of excrement (urine, stool) in the absorbent article and not to the user / patient's body. The pattern of the IDE preferably repeats in one direction, meaning the moisture sensor strip can be trimmed to fit the size of the absorbent article to which it is applied. The IDE can be contacted at any location along the electrode circumference / edge. The offset capacitance (initial capacitance) of the sensor is determined by the sensor length, the type of absorbent article, and the attachment method, such as the type or thickness of the adhesive. These specifications are predefined for a specific type of absorbent article.

[0043] Accordingly, in the method according to the basic embodiment, the first preferred embodiment, and the third preferred embodiment of the invention, or a preferred embodiment of the foregoing, the moisture sensor strip and the cover layer are not used separately from one another, but as a type of semi-finished product, i.e., prefabricated raw material, or as a type of laminate composed of the two aforementioned components. The moisture sensor strip and the cover layer are also bonded to one another according to the relative arrangement according to the invention. This considerably simplifies the application of the two components while simultaneously making them more precise. Since they are already bonded to one another, the two components can no longer slip relative to one another.Therefore, it is not necessary to ensure that the moisture sensor strip is correctly positioned relative to the absorbent article, the cover layer is correctly positioned relative to the absorbent article, and the moisture sensor strip is correctly positioned relative to the cover layer at the same time, but only that the bonded component consisting of the section of the moisture sensor strip and the section of the cover layer is correctly positioned relative to the absorbent article.

[0044] The third adhesive can be the same as the first and / or the second adhesive, but it can also be different from both.

[0045] According to a further preferred embodiment of the basic design, the endless roll comprises predefined separation areas for separating segments of the endless roll, wherein the separation areas are provided on the moisture sensor strip and the cover layer. These areas preferably have perforations. This indicates to the user a suitable location for separating segments of the endless roll. Furthermore, the separation process is considerably simplified. The user does not require additional tools such as scissors or knives. Handling is also simplified and, above all, more precise, since inaccuracies can be eliminated.

[0046] According to a first embodiment of the endless roll according to the invention, the endless roll comprises a plurality of identical segments in the longitudinal direction of the endless roll, wherein each segment comprises a first adhesive arranged on a second surface of the moisture sensor strip with the exception of a pocket portion of the moisture sensor strip, and a second adhesive arranged on a first surface of the cover layer, wherein in a pocket portion of the cover layer, the second adhesive is arranged on lateral edge regions of the pocket portion of the cover layer and an area between the lateral edge regions is free of the second adhesive. The endless roll further comprises at least one release paper covering the first adhesive and the second adhesive.This provides the user with a continuous roll for the inventive method, in which the moisture sensor strip is bonded to the cover layer, significantly simplifying the application of both components while simultaneously increasing precision. All necessary adhesives are provided by the continuous roll, the arrangement of the moisture sensor strip and cover layer is fixed, and in conjunction with the inventive method, the advantages described above are achieved.

[0047] In a further preferred embodiment, the separators are arranged between the identical segments. This provides a continuous roll comprising a plurality of identical segments suitable for attachment to an absorbent article and easily separated from one another. The user thus has a product at their disposal that allows them to simply and conveniently retrofit a plurality of absorbent articles with a section of the continuous strip.

[0048] A further aspect of the present disclosure relates to a first endless roll for use in the method according to the second preferred embodiment of the invention or a variant thereof, comprising a humidity sensor strip comprising two interdigitated electrodes printed with ink based on conductive materials onto a polymer substrate, preferably polyethylene terephthalate (PET), and preferably a plurality of pairs of two interdigitated electrodes, each printed with ink based on conductive materials onto the PET substrate and arranged laterally next to one another. This provides the first endless roll for the method according to the invention, which can be manufactured in a particularly simple and cost-effective manner. In particular, the side-by-side arrangement offers efficient manufacturing processes, such as roll-to-roll manufacturing processes.Roll-to-roll manufacturing of the humidity sensor strip on PET allows for the production of cost-effective and highly conductive sensors, enabling the use of impedance spectroscopy. A process for the production of a cost-effective, standalone humidity sensor strip from a roll based on printed electronics is presented.

[0049] In a further preferred embodiment, the two interdigitated electrodes are electrically insulated from each other and comprise electrode fingers with a length of less than 100 mm, preferably less than 50 mm and more preferably less than 10 mm and a distance from each other of 1 mm to 5 mm, preferably 1 mm to 4 mm and more preferably 1 mm to 2 mm. The scanning depth corresponds approximately to the distance between the individual fingers, whereby the scanning is limited to the absorbing material without including parts of the body in the measurement. Furthermore, the finger structure enlarges the scanning area without increasing the scanning depth, compared to the use of only two parallel conductor tracks. Wide parallel lines are not robust against external interference due to the great measuring depth. Therefore, the dimensions according to the invention are particularly suitable for a precisely defined measurement with a limited measuring range.

[0050] In another preferred embodiment, the PET substrate has a height of 10 to 500 µm, preferably 35 to 65 µm, more preferably 45 to 55 µm, and most preferably 50 µm. The thickness of 50 µm used for the height results in a substrate that is not too thin, so that it is still easy to handle and cure, and not too thick, so that the substrate becomes stiff, uncomfortable, or more expensive.

[0051] In a preferred embodiment of the present disclosure, the electrodes have a height of 1 to 50 µm, preferably 1 to 16 µm, more preferably 10 to 14 µm, and most preferably 12 µm, and are arranged coplanarly on the polymer substrate.

[0052] According to another preferred embodiment of the invention, at least one of the first adhesive, the second adhesive, and the third adhesive is a structural adhesive, a cold melt adhesive, or a hot melt adhesive. A structural adhesive is easily applied to an absorbent article on a high-speed production line. Cold melt adhesive, which can be described as a hot melt adhesive with a lower melting point and a lower application temperature, typically about 130°C or less, and hot melt adhesive can also be used. This is applied with a heated applicator on the production line and allows for very high speeds. Due to the homogeneous thickness, slotted application is preferable to spray application or segmented application.

[0053] More preferably, at least one of the first, second, and third adhesives is a pressure-sensitive adhesive, preferably comprising acrylate polymer, rubber, natural rubber, and / or synthetic thermoplastic elastomer. Polyacrylate-based pressure-sensitive adhesives (PSAs) can be screen-printed and cured onto the absorbent article, the moisture sensing strip, and / or the cover layer. This then allows for subsequent bonding of the corresponding components. Alternatively, pressure-sensitive adhesives in the form of pre-cured transfer tape can also be used. PSAs are useful for home care / nursing homes because the continuous roll can preferably be supplied with the adhesive on a release paper / liner for easy attachment.

[0054] In a further preferred embodiment, the first adhesive is an electrically insulating adhesive film with a thickness of 1 to 100 µm, preferably 5 to 75 µm, and more preferably 10 to 50 µm. The first adhesive provides additional insulation against potential liquids while simultaneously ensuring a reliable bond between the moisture sensor strip and the absorbent article.

[0055] According to a further preferred embodiment of the invention, the pressure-sensitive adhesive is printed onto the absorbent article and / or the moisture sensor strip, wherein the pressure-sensitive adhesive is cured. Preferably, the pressure-sensitive adhesive is applied using a screen printing process. Pressure-sensitive adhesives thus decouple the preparation and provision of an adhesive from the actual bonding process.

[0056] The cover layer preferably consists of a first layer containing the nonwoven material, wherein the nonwoven material preferably consists of polypropylene and / or PET.

[0057] More preferably, the cover layer comprises a first layer and a second layer, wherein the first layer comprises the nonwoven material, the nonwoven material preferably comprising polypropylene and / or PET, and wherein the second layer comprises a polymer film, preferably a polyethylene film. The selection of materials ensures that the cover layer has sufficient tensile strength to enable processing in the production line for absorbent articles and to allow the formation of a stable pocket that will not tear, yet is flexible enough for a potential clip to pierce the material.

[0058] Another aspect of the present disclosure relates to an apparatus for use in the method according to the third preferred embodiment (retrofit) of the invention, comprising a first roller for receiving an endless roll according to the first embodiment of the endless roll according to the invention or a preferred embodiment thereof, and a second roller for receiving the removed release paper. Furthermore, the apparatus comprises a first pressure roller and a second pressure roller, a variable-width gap between the first pressure roller and the second pressure roller, and a coupling element configured to operatively connect the first roller and the second roller and to synchronize rotation of the first roller and the second roller.Furthermore, the device comprises a preloaded spring arranged on the first pressure roller or the second pressure roller and configured to regulate the pressure of the pressure rollers by adjusting the width of the gap. This device makes it possible to subsequently connect previously manufactured absorbent articles to a segment of the continuous roll and to attach a sensor for moisture measurement. The absorbent article is pushed into the gap. There, a section of a moisture sensor strip and / or a section of a cover layer is brought into contact with the absorbent article. The release paper has been previously removed so that a first adhesive and / or a second adhesive comes into contact with the absorbent article. Furthermore, the release paper is continuously removed during insertion, if necessary because parts of the segment may still be covered by the release paper.Bonding is achieved through the pressure exerted by the pressure rollers. The absorbent article is gradually inserted so that a complete segment from the numerous segments is gradually bonded to the absorbent article. The absorbent article is then removed. The applied segment can be separated before or after removal.

[0059] The two rolls are coupled by the coupling element to ensure permanent tension on the release paper and to avoid interrupting the unwinding process. This provides a device that allows an absorbent article to be easily and quickly connected to a continuous roll according to the invention, thus subsequently converting it into an absorbent article capable of moisture measurement.

[0060] Another aspect of the present disclosure relates to a system manufactured in the basic embodiment of the inventive method, comprising an absorbent article, a continuous strip comprising a moisture sensing strip with two interdigitated electrodes printed on a PET substrate with ink based on conductive materials, a cover layer, and an access opening.The system further comprises a first adhesive disposed between a first partial surface of the absorbent article and a second surface of the moisture sensor strip, with the exception of a pocket region of the absorbent article, a second adhesive disposed between a second partial surface of the absorbent article and a first surface of the cover layer, wherein in the pocket region of the absorbent article, the second adhesive is disposed on lateral edge regions of the cover layer and an area between the lateral edge regions is free of the second adhesive, and wherein the cover layer overlaps both longitudinal edges of the moisture sensor strip. The system further comprises a pocket space delimited by the pocket region of the absorbent article, by the lateral edge regions of the cover layer, and by the area between the lateral edge regions, wherein the pocket space is accessible via the access opening.

[0061] The system preferably further comprises a third adhesive disposed at least intermittently between a first surface of the moisture sensor strip and the first surface of the cover layer material.

[0062] In a further preferred embodiment of the system, the system comprises a clip comprising an integrated circuit, a first pivotable element, a second pivotable element connected to the first pivotable element at a folding edge, and teeth, wherein the first pivotable element is arranged in the pocket space, wherein the cover layer is pierced by the teeth in a closed position of the clip for attaching the clip to the cover layer, and wherein the clip is positioned with the moisture sensor strip such that contact surfaces of the moisture sensor strip and contact pins of the clip are conductively connected to one another and that the moisture sensor strip is aligned between the teeth. With the aid of an integrated circuit, a voltage with a variable frequency is applied to the IDE and the current response between the electrodes is measured.A frequency-dependent impedance is calculated, and based on this, a frequency-dependent capacitance. The clip preferably consists of an elastomer element, particularly preferably a silicone element. The silicone elements are configured to hold the humidity sensor strip in the closed position of the clip, ensuring that electrical contact is maintained and sufficient pressure is applied to ensure low contact resistance.

[0063] The clip connected to the humidity sensor strip preferably contains an integrated circuit capable of generating sinusoidal voltages at different frequencies. These voltages are applied to one electrode (drive electrode) of the humidity sensor strip. Another electrode (sensing electrode) is used to measure the current through the sensor. For each frequency step, the frequency-dependent capacitance is calculated from the voltage and current amplitude and the phase shift between them. This is equivalent to measuring the complex impedance and calculating the capacitance from the imaginary part. The real part (ohmic resistance) is not used. The frequency-dependent capacitance is fitted to a power law, and a value called the capacitance can be calculated from the fitting coefficients. Power-law fitting is also used for noise reduction.

[0064] The various embodiments of the disclosure described herein may be advantageously combined with one another unless otherwise stated herein.

[0065] Reference is now made to the following figures to describe preferred embodiments of the invention in more detail. Fig. 1a shows a first endless roll in side view according to a preferred embodiment for use in the method according to the second preferred embodiment of the invention or a variant thereof; Fig. 1b shows a cross section through a section of the first endless roll of Fig. 1a; Fig. 1c shows a plan view of a section of the first endless roll of Fig. 1a; Fig. Figure 2 shows a snapshot of a method for joining an absorbent article and a continuous strip with a moisture sensing strip and a cover layer according to a second preferred embodiment or a preferred embodiment thereof; Fig. 3a shows part of the continuous strip of Fig. 2; Fig. Figure 3b illustrates the connection of the absorbent article to the part of the continuous strip; Fig. Figure 3 shows the connection of the absorbent article with the part of the continuous strip of Fig. 2; Fig. 3d shows the connection of the absorbent article with the part of the continuous stripa from Fig. 3b in a perspective view; Fig. 4a shows a system according to the invention with a partial sectional view, which was manufactured using a method according to the invention; Fig. 4b illustrates the system from Fig. 4a with a clip attached outside a pocket; Fig. 5 shows a device according to the invention for use in the method according to the third preferred embodiment (retrofit) of the invention in a perspective view; Fig. 5b shows a cross section through the device from Fig. 5a; Fig. Figure 6a illustrates a method of joining an absorbent article and a continuous strip with a moisture sensing strip and a cover layer according to a basic embodiment of the invention; Fig. Figure 6b shows a method for joining an absorbent article and a continuous strip with a moisture sensor strip and a cover layer according to a first variant of a second preferred embodiment; Fig. 6c shows a method of joining an absorbent article and a continuous strip with a moisture sensor strip and a cover layer according to a second variant of the second preferred embodiment; Fig. Figure 6d illustrates a method of joining an absorbent article and a continuous strip comprising a moisture sensing strip and a cover layer according to a third preferred embodiment.

[0066] The embodiments illustrated in the figures will now be discussed in detail. The effects and features of the embodiments will be described with reference to the accompanying figures. Like reference numerals denote like elements, and redundant descriptions will be omitted. However, the present invention may be embodied in various forms and should not be construed as being limited to the embodiments illustrated herein. Rather, these embodiments are provided merely as examples to fully convey the aspects and features of the present invention to those skilled in the art.

[0067] Fig. Figure 1a shows a first endless roll 40 in side view according to a preferred embodiment for use in the method according to the second preferred embodiment of the invention or a variant thereof. The first endless roll 40 comprises a humidity sensor strip 41 with two interdigitated electrodes, IDE, 422. Preferably, the IDE 422 is screen-printed with conductive carbon-based ink onto a flexible and flat PET substrate 421 and cured. The humidity sensor strip 41 is provided on a roll formed from the first endless roll 40. The humidity sensor strip 41 can be used as a cut strip or in a roll-to-roll process, the size depending on the length of the absorbent article. The moisture sensor strip 41 is preferably produced by roll-to-roll screen printing, although other processes, such as flexographic or (roto)gravure printing, are also possible.The inner diameter d and outer diameter y, as well as the width w, depend on the application. The width w is preferably optimized for convenience and cost reasons. A larger sensor would yield a higher signal, but costs would increase and convenience would decrease.

[0068] Fig. Figure 1b shows a cross-section through a portion of the first continuous roll. This qualitatively illustrates the relationship between the height of the IDE 422 printed with carbon-based conductive ink and the thickness of the PET substrate 421. The PET substrate 421 preferably has a thickness of 50 µm to be thin enough to be easily handled and cured, and not so thick that it becomes stiff, uncomfortable, or expensive.

[0069] Fig. 1c shows a plan view of a section of the first endless roll 40 from Fig. 1a. It shows a preferred embodiment of the IDE 422 arranged on the moisture sensor strip 41 printed on the PET substrate 421. The IDE 422 preferably has a height of approximately 12 µm in a coplanar arrangement. The electrode fingers of the IDE 422 preferably have a length of less than 10 mm and a pitch of 1 mm to 2 mm. The design of the IDE 422 is optimized so that the penetration depth of a generated electric field during an impedance measurement is no greater than 5 mm, which means that any change in the capacitance value can be attributed to the presence of excrement (urine, stool) in an absorbent article and not to the user / patient's body. The pattern of the IDE 422 repeats in one direction, which means that the first endless roll 40 can be cut to fit the size of the absorbent article to which it could be attached.The IDE 422 can be contacted at any point along the electrode circumference / edge. The offset capacitance (starting capacitance) of a sensor is determined by the length of an absorbent article, the type of absorbent article, and the type of attachment (e.g., type or thickness of the adhesive). These specifications are predefined for a specific type of absorbent article.

[0070] Fig. 2 shows a snapshot of a method for joining an absorbent article 10 and a continuous strip comprising a moisture sensor strip 41 and a cover layer 51, according to a second preferred embodiment or a preferred embodiment thereof. The absorbent articles include, in particular, pad products that are processed into a final product. The absorbent article 10, also called absorbent precursor 10, is such a precursor. It exists as a quasi-endless raw material that can be processed in further process steps. It is assumed that the finished absorbent articles 20, also called absorbent article finished products 20, in this case diapers 20, are obtained from the quasi-endless absorbent article 10 by cutting.

[0071] The cover layer 51 is preferably breathable and consists of a nonwoven fabric, e.g., polypropylene or PET.

[0072] As shown in the left section of the Fig. 2, the absorbent article 10 is located at the bottom, a first continuous roll 40 above it, and a second continuous roll 50 at the top. The first continuous roll 40 is preferably the one shown in the Fig. 1a-1c. The first endless roll 40 thus comprises a moisture sensor strip 41, and the second endless roll 50 comprises a cover layer 51, with both the moisture sensor strip 41 and the cover layer 51 being unrolled from the rolls 40, 50. The illustrated snapshot of the roll-to-roll process includes both the first variant of the second preferred embodiment and the second variant of the second preferred embodiment.

[0073] Not shown, but also present, are a first adhesive applied between the moisture sensor strip 41 and a first partial surface 31 for bonding a portion of the moisture sensor strip 42 to the first partial surface 31 of the absorbent article 10, 20, wherein in a pocket region 33 of the absorbent article 10, 20, no bonding of the moisture sensor strip 41 to the first partial surface 31 takes place, and a second adhesive applied between the cover layer 51 and a second partial surface 32 for bonding a portion of the cover layer 52 to the second partial surface 32 of the absorbent article 10, 20, wherein in the pocket region 33 of the absorbent article 10, 20, lateral edge regions 521 of the cover layer 51 are bonded to the absorbent article 10, 20.while an area between the lateral edge areas 521 remains free of adhesive and wherein the cover layer 51 overlaps both longitudinal edges of the moisture sensor strip 41.,

[0074] As in the right area of ​​the Fig. 2, the separating edges of the absorbent article 20 are already indicated. The section of the moisture sensor strip 42 is placed on the absorbent article 20 and bonded to the first partial surface 31 of the absorbent article 20. In addition, the section of the cover layer 52 is bonded to the second partial surface 32 of the absorbent article 20, and the cover layer 51 overlaps the two longitudinal edges of the moisture sensor strip. In the pocket area 33 of the absorbent article 20, lateral edge areas 521 of the cover layer 51 are bonded to the absorbent article 20, while an area between the lateral edge areas 521 remains free of adhesive (see Fig. 3b for the lateral edge areas 521). In Fig. 2, an access opening 522 to a pocket space 523 is indicated, which is delimited by the pocket region 33 of the absorbent article 20, by the lateral edge regions 521 of the cover layer 51 and by the region between the lateral edge regions 521, the pocket space 523 being accessible via the access opening 522.

[0075] In the case of the first variant or the second variant of the second embodiment of the invention, a third adhesive is also present, which is applied between at least a part of the humidity sensor strip 41 and a part of the cover layer 51, but is not shown.

[0076] Fig. 3a shows part of the continuous strip of Fig. 2, which is the first variant of the second preferred embodiment, in which, before the section of the moisture sensor strip 42 is bonded to the first partial surface 31 of the absorbent article 10, 20 and before the section of the cover layer 52 is bonded to the second partial surface 32 of the absorbent article 10, 20, the moisture sensor strip 41 is bonded to the cover layer 51 by the third adhesive, which is applied between at least a part of the moisture sensor strip 41 and a part of the cover layer 51. This thus results in a type of semi-finished product or laminate, which is subsequently bonded to the absorbent article 10, 20, as described above.

[0077] Fig. Figure 3b shows the connection of the absorbent article with the part of the continuous strip of Fig. 3b. The dashed line shows the area between the two lateral edge regions 521, within which, on the one hand, the cover layer 51 is not bonded to the absorbent article 20 and, on the other hand, preferably the moisture sensor strip 41 is also not bonded to the absorbent article 20 and the cover layer 51. The dashed line also shows the pocket region 33.

[0078] Fig. Figure 3c shows the absorbent article finished product 20 provided with the part of the continuous strip of Fig. 2. The absorbent article finished product 20 is separated from the absorbent article pre-product 10 along the separating edges and represents the final product.

[0079] Fig. 3d shows the connection of the absorbent article with the part of the continuous strip of Fig. 3b in a perspective view. This indicates that, due to the materials used for both the cover layer 51 and the moisture sensor strip 41, the absorbent finished article 20 retains its flexibility in the assembled form while simultaneously reliably maintaining the bond thanks to the appropriately selected adhesives.

[0080] Fig. 4a shows a system 80 according to the invention with a partial sectional view, which was manufactured using a method according to the invention. The system 80 comprises the absorbent article 20, a continuous strip comprising a moisture sensor strip 41 with two interdigitated electrodes 422 printed on a PET substrate 421 with ink based on conductive materials, and a cover layer 51 and an access opening 522. The system 80 further comprises a first adhesive (not shown) arranged between the first partial surface 31 of the absorbent article 20 and a second surface of the moisture sensor strip 41, excluding a pocket region 33 of the absorbent article 20. The second surface of the moisture sensor strip 41 faces an outer surface of the absorbent article 20.A second adhesive (not shown) is arranged between the second partial surface 32 of the absorbent article 20 and a first surface of the cover layer 51. In the pocket region 33 of the absorbent article 20, the second adhesive is arranged on lateral edge regions 521 of the cover layer 51. The first surface of the cover layer 51 faces the outer surface of the absorbent article 20. An area between the lateral edge regions 521 is free of the second adhesive, and the cover layer 51 overlaps both longitudinal edges of the moisture sensor strip 41. Furthermore, a pocket space 523 is shown, which is delimited by the pocket region 33 of the absorbent article 20, by the lateral edge regions 521 of the cover layer 51, and by the area between the lateral edge regions 521. The pocket space 523 is accessible via the access opening 522.Also shown is a clip 60 having an integrated circuit (not shown), a first pivotable element 61, a second pivotable element 62 connected to the first pivotable element 61 at a folded edge 63, and teeth 64. The first pivotable element 61 is arranged in the pocket space 523, with the cover layer 51 being pierced by the teeth 64 in a closed position of the clip 60 (not shown) in order to secure the clip 60 to the cover layer 51. The clip 60 is aligned with the humidity sensor strip 41 such that contact pads (not shown) of the humidity sensor strip 41 and contact pins 66 of the clip 60 are conductively connected to one another and such that the humidity sensor strip 41 is aligned between the teeth 64. The teeth 64 of the clip 60 pierce the cover layer 51 and hold it in position.The pocket space 523 is preferably designed to be sealed, which facilitates the alignment of the clip 60 with the moisture sensor strip 41. The dimensions of the pocket space 523 are configured so that the contact pins align correctly and easily with the circumferential conductor tracks of the IDE 422 while securely holding the clip 60 in place. When the clip 60 is not inserted, e.g., when the absorbent article 20 is being packaged, no bulk is added to the absorbent article 20. A nonwoven fabric with a sufficiently low basis weight is selected to allow the teeth to pierce the pocket space 523, ensuring that the clip 60 stays in place. The clip 60 squeezes the moisture sensor strip 41 between the contact pins 66 of the clip 60 and the pivoting elements 61, 62 on the folded edge 63.This places pressure on the back of the humidity sensor strip 41 and presses it against the contact pins. Silicone pins 65 in the wearable clip hold the humidity sensor strip 41 in the closed position of the clip, ensuring that electrical contact is maintained and sufficient pressure is applied to ensure low contact resistance.

[0081] Fig. 4b shows the system 80 from Fig. 4a, wherein the clip 60 is arranged outside the pocket space 523.

[0082] Fig. 5a shows a perspective view of a device 70 according to the invention for use in the method according to the third preferred embodiment (retrofit) of the invention. The device 70 comprises a first roller 71 for receiving an endless roll 78 according to the first embodiment of an endless roll according to the invention or a preferred embodiment thereof. The device 70 further comprises a second roller 72 for receiving the unrolled release paper 77, a first pressure roller 73, and a second pressure roller 74. A gap 75 of variable width is formed between the first pressure roller 73 and the second pressure roller 74. A coupling element (not shown) is configured to operatively connect the first roller 71 and the second roller 72 and to synchronize rotation of the first roller 71 and the second roller 72.A preloaded spring, also not shown, is arranged on the first pressure roller 73 or the second pressure roller 74 and is configured to adjust the pressure of the pressure rollers 73, 74 by adjusting the width of the gap 75. The endless roller 78 arranged on the first roller 71 comprises a humidity sensor strip 41 comprising two interdigitated electrodes IDE, 422 printed on a PET substrate with ink based on conductive materials, a cover layer 51 comprising a nonwoven material and an access opening 522 to a pocket space 523, and a third adhesive arranged at least intermittently between a first surface of the humidity sensor strip 41 and a first surface of the material of the cover layer 51, wherein no third adhesive is arranged in the pocket space 523.The endless roll 78 further comprises a plurality of identical segments in a longitudinal direction of the endless roll 78, each segment comprising a first adhesive disposed on a second surface of the humidity sensor strip 41 except for a pocket portion of the humidity sensor strip 41, and a second adhesive disposed on a first surface of the cover layer 51, wherein in a pocket portion of the cover layer 51, the second adhesive is disposed at lateral edge regions 521 of the pocket portion of the cover layer 51, wherein an area between the lateral edge regions 521 is free of the second adhesive, and at least one release paper covering the first adhesive and the second adhesive.The endless roll 78 preferably has predefined separation areas, preferably perforations, for separating segments of the endless roll 78, wherein the separation areas are provided on the moisture sensor strip 41 and the cover layer 51. Also shown is an end 79 of a section of a continuous strip 76, which is arranged in front of the first pressure roller 73 and the second pressure roller 74.

[0083] Fig. 5b shows a cross section through the device from Fig. 5a. Here, it can be seen that the section of the continuous strip 76, which comprises a section of the moisture sensor strip 42 and a section of the cover layer 52, is unrolled before being adhered to an absorbent article 10, 20. The direction of movement of the unrolled section of the continuous strip 76 is represented by the direction of movement D1. It also shows how the release paper is removed after the section of the continuous strip 76 has been unrolled and before the section of the moisture sensor strip 42 and / or before the section of the cover layer 52 is adhered to the absorbent article 10, 20. The peeled release paper 77 is deflected by a small roller, represented by the rotation arrow, and then, after moving along the direction of movement D3, the peeled release paper 77 is wound onto the release paper roll 72.The exposed portion of the moisture sensor strip 42 and / or a portion of the cover layer 52 forms an end, and the absorbent article 10, 20 can receive the end 79 when the portion of the continuous strip 76 is inserted through the absorbent article 10, 20 into the gap 7.

[0084] Fig. Figure 6a illustrates a method for joining an absorbent article and a continuous strip comprising a moisture sensing strip and a cover layer according to a basic embodiment of the invention. The method is described with reference to Fig. 2 and 3a-3c, since this figure is particularly suitable for this form of the roll-to-roll process, but is by no means limited thereto. In a first step S100, a section of the moisture sensor strip 42 is bonded to the first partial surface 31 of the absorbent article 10, 20 by applying the first adhesive between the moisture sensor strip 41 and the first partial surface 31, wherein in the pocket region 33 of the absorbent article 10, 20, there is no adhesion of the moisture sensor strip 41 to the first partial surface 31. The adhesion-free region is also shown in Fig. 3b by the dashed line. In a second step S200, the section of the cover layer 52 is bonded to the second partial surface 32 of the absorbent article 10, 20 by applying the second adhesive between the cover layer 51 and the second partial surface 32, wherein in the pocket region 33 of the absorbent article 10, 20, lateral edge regions 521 of the cover layer 51 are bonded to the absorbent article 10, 20, while an area between the lateral edge regions 521 remains free of adhesive, which is also the case in Fig. 3b, and wherein the cover layer 51 overlaps both longitudinal edges of the moisture sensor strip (41). After step S200, in step S300, the bonded portion of the moisture sensor strip 42 and the bonded portion of the cover layer 52 are separated from the continuous strip. Steps S100 and S200 are clearly visible in the left area of Fig. 2, while after step S300, i.e. the separation, the situation is then as in the right area of ​​the Fig. 2. In the last step of the first embodiment, the access opening 522 to the pocket space 523, which is delimited by the pocket region 33 of the absorbent article 10, 20, by the lateral edge regions 521 of the cover layer 51 and by the region between the lateral edge regions 521, is provided, wherein the pocket space 523 is accessible via the access opening 522.

[0085] Fig. Figure 6b illustrates a method for joining an absorbent article and a continuous strip with a moisture sensor strip and a cover layer according to a first variant of a second preferred embodiment. Therefore, steps S100 to S400 do not differ in content. However, the method now begins with step S100A. In step S100A, the moisture sensor strip 41 is bonded to the cover layer 51 by applying the third adhesive between at least a portion of the moisture sensor strip 41 and a portion of the cover layer 51. Therefore, Fig. 2 no longer applies to this embodiment of the method according to the invention, since there the cover layer and the moisture sensor strip are at least not bonded to each other before the moisture sensor strip is bonded to the absorbent article. However, the other features such as relative arrangements, etc., and the final product remain valid.

[0086] Fig. Figure 6c illustrates a method for joining an absorbent article and a continuous strip comprising a moisture sensor strip and a cover layer according to a second variant of the second preferred embodiment. The method shown there corresponds to that shown in Fig. 6b, with the difference that the method begins with step S100, ie the bonding of the section of the moisture sensor strip 41 on the first partial surface 31 of the absorbent article, followed by step S100A, ie the bonding of the moisture sensor strip 41 on the cover layer 51. Accordingly, the method shown in the left area of Fig. 2 also applies to this embodiment of the method according to the invention.

[0087] Fig. Figure 6d illustrates a method for joining an absorbent article and a continuous strip comprising a moisture sensor strip and a cover layer according to a third preferred embodiment. The method is described with reference to Fig. 4a and Fig. 4b and the Fig. 5a and Fig. 5b, as this figure is particularly suitable for this type of retrofitting, but is by no means limited to it. Fig. 5a and Fig. 5b show a device for use in the described method. The continuous strip is provided as an endless roll 78 comprising the moisture sensor strip 41 adhered to the cover layer 51, and in step S100B, a portion of the continuous strip 76 comprising the portion of the moisture sensor strip 42 and the portion of the cover layer 52 is unrolled. In step S100C, the release paper is removed. In step S100D, the removed release paper, which is produced by the device according to Fig.5b is deflected, wound onto a release paper roll 72. The end of the section of the continuous strip 76 is arranged in front of the first pressure roller 73 and the second pressure roller 74, and the absorbent article 10, 20 receives the end when the section of the continuous strip 76 is inserted into the gap 75 by inserting the absorbent article 10, 20. Subsequently, in step S100E, pressure is exerted on the section of the continuous strip using the pressure rollers 73, 74. The previously described steps S100 to S400 now follow, wherein the bonding of the section of the moisture sensor strip 42 to the first partial surface 31 of the absorbent article 10, 20 and the bonding of a section of the cover layer 52 to the second partial surface 32 of the absorbent article 10, 20 currently take place simultaneously. List of reference symbols 10 Pre-product of an absorbent article 20 Final product of an absorbent article 31 first sub-area 32 second sub-area 33 Pocket area 40 first endless roll 41 moisture sensor strips 42 Section of the humidity sensor strip 421 PET substrate 422 IDE 50 second endless roll 51 Top layer 52 Section of the surface layer 521 lateral edge area 522 access opening 523 pocket space 60 clips 61 first pivoting element 62 second pivoting element 63 folding edge 64 teeth 65 silicon pins 66 contact pins 70 Device 71 First role 72 second roll / release paper roll 73 first printing roller 74 second pressure roller 75 gap 76 Section of the continuous strip 77 removed release paper 78 endless roll 79 End of section of continuous strip 80 systems d inner diameter y outer diameter w Width of the first endless roll D1, D2, D3 directions of movement S100A Bonding the moisture sensor strip to the cover layer S100 Unrolling the section of the continuous strip S100 Removing the release paper S100D Winding the removed release paper onto a release paper roll S100E Applying pressure to the continuous strip S100 Bonding a portion of the moisture sensor strip to a first partial surface of the absorbent article S200 Bonding a portion of the cover layer to a second partial surface of the absorbent article S300 Separating the bonded portion of the moisture sensor strip and the bonded portion of the cover layer from the continuous strip S400 Providing an access opening to a pocket space

Claims

[1] A method of joining an absorbent article (10, 20) and a continuous strip comprising a moisture sensing strip (41) and a cover layer (51), the method comprising the following steps: Bonding a portion of the moisture sensor strip (42) to a first partial surface (31) of the absorbent article (10, 20) by applying a first adhesive between the moisture sensor strip (41) and the first partial surface (31), wherein in a pocket region (33) of the absorbent article (10, 20) there is no adhesion of the moisture sensor strip (41) to the first partial surface (31); Bonding a section of the cover layer (52) to a second partial surface (32) of the absorbent article (10, 20) by applying a second adhesive between the cover layer (51) and the second partial surface (32), wherein in the pocket region (33) of the absorbent article (10, 20) lateral edge regions (521) of the cover layer (51) are bonded to the absorbent article (10, 20), while a region between the lateral edge regions (521) remains free of adhesive and wherein the cover layer (51) overlaps both longitudinal edges of the moisture sensor strip (41); Separating the adhered portion of the moisture sensor strip (42) and the adhered portion of the cover layer (52) from the continuous strip; and Providing an access opening (522) to a pocket space (523) which is delimited by the pocket region (33) of the absorbent article (10, 20), by the lateral edge regions (521) of the cover layer (51) and by the region between the lateral edge regions (521), wherein the pocket space (523) is accessible via the access opening (522). [2] The method of claim 1, wherein the pocket space (523) is configured to: to receive a clip (60) with an integrated circuit, a first pivotable element (61) and a second pivotable element (62) connected to the first pivotable element (61) at a folding edge (63), wherein a size of the pocket space (523) is adapted to the size of the first pivotable element (61), to be pierced by teeth (64) of the second pivotable element (62) in a closed position of the clip (60) in order to secure the clip (60) to the cover layer (51), and align the clip (60) with the moisture sensor strip (41) so that contact surfaces of the moisture sensor strip (41) and contact pins (66) of the clip (60) are conductively connected to one another, and so that the moisture sensor strip (41) is aligned between the teeth (64). [3] A method according to claim 1 or 2, wherein the continuous strip is provided as an endless roll (78) comprising the moisture sensor strip (41) adhered to the cover layer (51), and wherein a portion of the continuous strip (76) comprising the portion of the moisture sensor strip (42) and the portion of the cover layer (52) is unrolled before being adhered to the absorbent article (10, 20). [4] The method according to claim 1 or 2, wherein the moisture sensor strip (41) is provided as a first endless roll (40) and the cover layer (51) is provided as a second endless roll (50). [5] The method according to claim 4, wherein the method further comprises, prior to bonding the portion of the moisture sensor strip (42) to the first partial surface (31) of the absorbent article (10, 20) and prior to bonding the portion of the cover layer (52) to the second partial surface (32) of the absorbent article (10, 20): Bonding the moisture sensor strip (41) to the cover layer (51) by applying a third adhesive between at least a part of the moisture sensor strip (41) and a part of the cover layer (51). [6] The method of claim 4, wherein the method further comprises, after bonding the portion of the moisture sensor strip (42) to the first partial surface (31) of the absorbent article (10, 20): Bonding the moisture sensor strip (41) to the cover layer (51) by applying a third adhesive between the moisture sensor strip (41) and the cover layer (51) [7] The method of claim 6, wherein the moisture sensor strip (41) in the pocket region (33) of the absorbent article (10, 20) remains free of adhesive in the region between the lateral edge regions (521). [8] A method according to claim 3 or 5, wherein the moisture sensor strip (41) is intermittently adhered to the cover layer (51) and wherein a non-adhered portion of the moisture sensor strip (41) is overlaid with the pocket portion (33) before the moisture sensor strip (41) is adhered to the absorbent article (10, 20). [9] The method of claim 3, wherein the endless roll (78) further comprises the first adhesive, the second adhesive, and at least one release paper for covering the first adhesive and the second adhesive, and wherein the method further comprises: Removing the release paper after unrolling the portion of the continuous strip (76) and before bonding the portion of the moisture sensor strip (42) and / or before bonding the portion of the cover layer (52) to the absorbent article (10, 20). [10] The method of claim 9, wherein the method further comprises: Winding the removed release paper (77) onto a release paper roll (72); and Applying pressure to the portion of the continuous strip (76) with a pressure roller (73, 74) while adhering the portion of the moisture sensor strip (42) and the portion of the cover layer (52) to the absorbent article (10, 20), wherein the endless roll (78) and the release paper roll (72) are connected to one another by means of a gear comprising a clutch. [11] Method according to claim 10, wherein the pressure of the pressure roller (73, 74) is adjusted by a preloaded spring. [12] A method according to claim 10 or 11, wherein the pressure is exerted by a first pressure roller (73) and a second pressure roller (74) forming a gap (75) into which the absorbent article (10, 20) is inserted to adhere the portion of the moisture sensor strip (42) and the portion of the cover layer (52) to the absorbent article (10, 20). [13] The method of claim 12, wherein an end of the portion of the continuous strip (76) is disposed in front of the first pressure roller (73) and the second pressure roller (74), and the absorbent article (10, 20) receives the end when the portion of the continuous strip (76) is inserted into the nip (75). [14] An endless roll (78) of continuous strip for use in the method of any one of claims 1 to 3 and 8 to 13, wherein the endless roll (78) comprises: a humidity sensor strip (41) comprising two interdigitated electrodes, IDE, (422) printed with ink based on conductive materials on a polymer substrate, preferably a polyethylene terephthalate, PET, substrate; a cover layer (51) comprising a nonwoven material and an access opening (522) to a pocket space (523); and a third adhesive disposed at least intermittently between a first surface of the moisture sensor strip (41) and a first surface of the cover layer material, wherein no third adhesive is disposed in the pocket space (523). [15] Endless roll (78) according to claim 14, comprising predefined separation areas for separating segments of the endless roll (78), the separation areas being provided on the moisture sensor strip (41) and the cover layer (51). [16] The endless roll (78) of claim 14 or 15 for use in the method of any one of claims 3 and 9 to 13, wherein the endless roll (78) comprises a plurality of identical segments in a longitudinal direction of the endless roll (78), each segment comprising: a first adhesive disposed on a second surface of the humidity sensor strip (41) except for a pocket portion of the humidity sensor strip (41); a second adhesive arranged on a first surface of the cover layer (51), wherein in a pocket portion of the cover layer (51) the second adhesive is arranged on lateral edge regions (521) of the pocket portion of the cover layer (51) and a region between the lateral edge regions (521) is free of the second adhesive; and at least one release paper covering the first adhesive and the second adhesive. [17] Endless roll (78) according to claims 15 and 16, wherein the separating regions are arranged between the same segments. [18] A first endless roll (40) for use in the method according to any one of claims 4 to 7, comprising a humidity sensor strip (41) comprising two interdigitated electrodes, IDE, (422) printed with ink based on conductive materials on a polymer substrate, preferably a polyethylene terephthalate, PET, substrate (421), and preferably a plurality of pairs of two interdigitated electrodes (422), each printed with ink based on conductive materials on the PET substrate (421) and arranged laterally next to each other. [19] Endless roller (78) according to one of claims 14 to 18, wherein the two intermeshing electrodes (422) are electrically insulated from each other and have electrode fingers with a length of less than 100 mm, preferably less than 50 mm and more preferably less than 10 mm and a distance from each other of 1 mm to 5 mm, preferably 1 mm to 4 mm and more preferably 1 mm to 2 mm. [20] Endless roll (78) according to one of claims 14 to 19, wherein the PET substrate (421) has a height of 10 to 500 µm, preferably 35 to 65 µm, more preferably 45 to 55 µm and particularly preferably 50 µm. [21] Endless roll (78) according to one of claims 14 to 20, wherein the electrodes have a height of 1 to 50 µm, preferably 1 to 16 µm, more preferably 10 to 14 µm and particularly preferably 12 µm and are arranged coplanar on the polymer substrate (421). [22] The endless roll (78) of any one of claims 14 to 21, wherein at least one of the first adhesive, the second adhesive, and the third adhesive is one of a structural adhesive, a cold melt adhesive, and a hot melt adhesive. [23] The endless roll (78) of any one of claims 14 to 22, wherein at least one of the first adhesive, the second adhesive, and the third adhesive is a pressure-sensitive adhesive, preferably comprising acrylate polymer, rubber, natural rubber, and / or synthetic thermoplastic elastomer. [24] Endless roll (78) according to one of claims 14 to 23, wherein the first adhesive is an electrically insulating adhesive film having a thickness of 1 to 100 µm, preferably 5 to 75 µm and more preferably 10 to 50 µm. [25] The endless roll (78) of claim 24, wherein the pressure-sensitive adhesive is printed onto the absorbent article (10, 20) and / or the moisture sensor strip (41), and wherein the pressure-sensitive adhesive is cured. [26] Endless roll (78) according to one of claims 14 to 25, wherein the cover layer (51) comprises a first layer and a second layer, wherein the first layer comprises the nonwoven material, wherein the nonwoven material preferably comprises polypropylene and / or PET, and wherein the second layer comprises a polymer film, preferably a polyethylene film. [27] Apparatus (70) for use in the method according to claims 9 to 13, comprising a first roll (71) for receiving an endless roll (78) according to claims 16 to 26; a second roller (72) for receiving the removed release paper (77); a first pressure roller (73) and a second pressure roller (74); a gap (75) formed with a variable width between the first pressure roller (73) and the second pressure roller (74); a coupling member configured to operatively connect the first roller (71) and the second roller (72) and to synchronize rotation of the first roller (71) and the second roller (72); and a preloaded spring disposed on the first pressure roller (73) or the second pressure roller (74) and configured to adjust the pressure of the pressure rollers (73, 74) by adjusting the width of the gap (75). [28] System (80) manufactured by the method of claim 1, comprising an absorbent article (10, 20); a continuous strip comprising a humidity sensor strip (41) with two interdigitated electrodes (422) printed with conductive material-based ink on a PET substrate (421), a cover layer (51) and an access opening (522); a first adhesive disposed between a first partial surface (31) of the absorbent article (10, 20) and a second surface of the moisture sensor strip (41) except for a pocket region (33) of the absorbent article (10, 20); a second adhesive arranged between a second partial surface (32) of the absorbent article (10, 20) and a first surface of the cover layer (51), wherein in the pocket region (33) of the absorbent article (10, 20), the second adhesive is arranged on lateral edge regions (521) of the cover layer (51), and an area between the lateral edge regions (521) is free of the second adhesive, and wherein the cover layer (51) overlaps both longitudinal edges of the moisture sensor strip (41); and a pocket space (523) delimited by the pocket region (33) of the absorbent article (10, 20), by the lateral edge regions (521) of the cover layer (51), and by the area between the lateral edge regions (521), wherein the pocket space (523) is accessible via the access opening (522). [29] The system (80) of claim 28, further comprising a third adhesive disposed at least intermittently between a first surface of the moisture sensor strip (41) and the first surface of the cover layer material. [30] System (80) according to claim 28 or 29, further comprising: a clip (60) comprising an integrated circuit, a first pivotable element (61), a second pivotable element (62) connected to the first pivotable element (61) at a folding edge (63), and teeth (64), wherein the first pivotable element (61) is arranged in the pocket space (523), wherein the cover layer (51) is pierced by the teeth (64) in a closed position of the clip (60) to secure the clip (60) to the cover layer (51), and wherein the clip (60) is aligned with the moisture sensor strip (41) such that contact surfaces of the moisture sensor strip (41) and contact pins (66) of the clip (60) are conductively connected to one another and that the moisture sensor strip (41) is aligned between the teeth (64).

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