Method and device for producing an adhesive lock and adhesive lock

Abstract

The invention relates to a method for producing an adhesive closure (12) having a plurality of adhesive elements (28) with an end-side contact surface (32) for rereleasable adhesion to another component by an adhesive force, said adhesive elements (28) being formed from a coating material (16) in a forming cavity (18) of a forming screen (30) of a forming tool (20). In the method, the coating material (16) is supplied with a carrier sheet (36) and an adhesive element (38) is shaped on a side (36a) of the carrier sheet (36) facing the coating material (16) in a shaping cavity (20) of the shaping tool (20), preferably the carrier sheet (36) is connected to the coating material (16) before the adhesive element (28) is shaped. The invention also relates to a device (10) for producing such an adhesive closure (12) and to an adhesive closure (12).

Description

Field of the Invention

[0001] The present invention relates to a method for manufacturing an adhesion fastener having a plurality of adhesion elements, the adhesion elements having end-side contact surfaces for releasably adhering to other components by adhesion. The adhesion elements are formed from a coating material in a forming cavity of a forming screen of a forming tool. The present invention also relates to a device for manufacturing an adhesion fastener, the device comprising: a forming tool having a forming screen in which a forming cavity is formed; and a supply device for supplying the coating material to the forming cavity of the forming tool, the forming cavity being configured to form a plurality of adhesion elements having end-side contact surfaces for releasably adhering to other components by adhesion. The present invention also relates to an adhesion fastener comprising: a plurality of adhesion elements made of a coating material, the adhesion elements having end-side contact surfaces for releasably adhering to other components by adhesion. Background Art

[0002] WO 2012 / 031658 A1 discloses an adhesion fastener having a carrier part and a locking part erected on the carrier part, the locking part respectively having a head part which has at least one contact surface on its free end side for releasably adhering to another component by adhesion. When manufacturing such an adhesion fastener, the locking part is formed in a forming cavity of a metal forming screen by pressing a coating material or a plastic material into the forming cavity of the forming screen and forming the locking part from the coating material on the side of the carrier part assigned to the forming roller.

[0003] As also disclosed in WO 2012 / 031658 A1, the attachment mechanism for releasably adhering to (at least one) other component is a so-called Van-der-Waals interaction, which is classically regarded as a grouping of attachments. This attachment enables the adhesion elements to also reliably adhere to components having a smooth surface, such as on a window glass. This attachment is mainly achieved by making the contact surface have a small area, for example, about 0.2 µm 2 to about 0.5 µm 2 in area.

[0004] EP1827795B1 describes a method for manufacturing a carrier sheet from a predefined amount of plastic material, the carrier sheet having a plurality of forming elements which are formed in the forming cavities of a forming tool and are configured as mushroom-shaped hook structures. In a part of the forming cavities, cavities are formed inside the forming elements. The respective cavities in the forming elements can be closed by a locking web at least on one side. The hook structures are intended to engage with other hook structures, for example with a fluff material or a hook material.

[0005] US 2024 / 0034912 A1 describes a microfiber array having a plurality of fibers with rough tips which are in contact with the surface of a smooth flat object. The microfiber array is intended to achieve friction and controllable adhesion with respect to movement in the horizontal direction in order to be easily separated from the surface of the object in the vertical direction. The microfiber array is formed from a curable polymer using a forming tool. A replication negative mold of the microfiber array with fluffed tips can be formed by means of a casting material and a further microfiber array can be formed by means of the replication negative mold.

[0006] The article “Enhanced Flexible Mold Lifetime for Roll-to-Roll Scaled-Up Manufacturing of Adhesive Complex Microstructures”, J.-K. Kim et al., Adv. Mater. 2023, 35, 2207257 describes a roll-to-roll method for manufacturing a microstructured / nanostructured surface, the form of which is, for example, a gecko-like microfiber adhesion structure. It is proposed here to increase the service life of a flexible microstructured silicone rubber forming tool used in the roll-to-roll method by implementing a two-stage hardening process using UV (ultraviolet) light.

[0007] EP3448671B1 describes a method for assembling an arrangement system comprising a strip of retaining elements and a substrate. In the step of forming the strip, a strip comprising retaining elements is formed by dispensing a forming material in a forming device. Immediately following the step of forming the strip, a matrix is applied to the underside of the strip substrate facing away from the retaining elements and then the underside of the strip substrate is cured. Summary of the Invention

[0008] The object of the present invention is to provide a method and a corresponding device which can be implemented robustly and in which material can be saved in the manufacture of adhesion locks. The object of the present invention is also to provide a corresponding adhesion lock.

[0009] According to a first aspect, the object is achieved by a method of the type described above, in which a carrier sheet is supplied to the coating material and an adhesion element is formed in a forming cavity of the forming tool on a side of the carrier sheet facing the coating material, preferably connecting the carrier sheet to the coating material before forming the adhesion element. In the present application, the terms "plastic material" and "coating material" as well as the terms "plastic sheet" and "coating sheet" are used as synonyms.

[0010] In the method according to the invention, a carrier sheet is supplied to the coating material, and when the adhesion element is formed, the coating material is connected to the carrier sheet. This improves the robustness of the manufacturing process because the manufacturing process is insensitive to the rheology of the coating material. It is also possible to prevent the coating material from tearing during the manufacturing process, for example when demolding from the forming tool, by means of the carrier sheet connected to the coating material, or the coating material can be made thinner compared to the case where no carrier sheet is used during the manufacturing process. The coating material can be sucked into the forming tool by capillary force.

[0011] Advantageously, the connection between the carrier sheet and the coating material is achieved before the adhesion element is formed. The coating material can be connected to the carrier sheet, for example, in the form of a coating. The connection can be achieved, for example, by supplying the (strip-shaped) coating material and the carrier sheet together to the forming tool and bringing them into contact with each other when or before being supplied to the forming tool. It is also possible to press the coating material and the carrier sheet against each other during supply in order to facilitate the connection between the carrier sheet and the coating material. Thus, the connection between the coating material and the carrier sheet is established before the carrier sheet and the coating material reach the forming tool.

[0012] In a variant, when the adhesive element is formed, a coating sheet is formed between the carrier sheet and the adhesive element from the coating material. The coating sheet has a thickness of 2 mm or less, preferably 300 µm or less, particularly preferably 200 µm or less, most particularly preferably 50 µm or less, especially preferably 30 µm or less, and particularly 10 µm or less. In this variant, the adhesive element is formed on the side of the integral coating sheet facing away from the carrier sheet by pressing the coating material into the forming cavity of the forming tool or by flowing the coating material into the forming cavity of the forming tool. Due to the carrier sheet connected to the coating sheet, the thickness of the coating sheet can be achieved significantly smaller compared to the case of manufacturing the adhesion fastener without using the carrier sheet. In this way, coating material can be saved during the manufacture of the adhesion fastener, and energy can be saved during the polymerization of the coating material, that is, an adhesion fastener with better sustainability can be manufactured under the same functionality. Due to the smaller thickness of the coating sheet, the flexibility of the adhesion fastener is increased, which can be advantageous for the attachment characteristics of the adhesion fastener, for example, on a component with a curved surface.

[0013] In another variant, after the adhesive element is demolded from the forming cavity of the forming tool, the carrier sheet is separated from the coating sheet. In this case, the carrier sheet is a sacrificial sheet, and the sacrificial sheet is only used to make the manufacturing process more robust, but the sacrificial sheet is no longer used on the adhesion fastener itself. However, the carrier sheet can also have an adhesive layer or an adhesive coating on its side facing the coating material, and the adhesive layer or adhesive coating remains on the coating sheet with the adhesive element after the carrier sheet is separated from the coating sheet. In this case, the separation of the carrier sheet from the coating sheet is usually carried out directly by the operator before using the adhesion fastener, for example, in order to fix the adhesion fastener on a rigid component using the adhesive layer.

[0014] Alternatively, the carrier sheet can be permanently or inseparably connected to the coating sheet and form part of the adhesion fastener. This permanent connection between the carrier sheet and the coating sheet can be established especially without using a bonding agent in the form of an adhesive. If necessary, in order to establish the permanent connection, the carrier sheet can have an adhesion promoter layer or the surface of the carrier sheet can be surface-treated (see below).

[0015] In an alternative variant, the adhesive element is formed directly on the side of the carrier sheet facing the coating material. In this case, there is no continuous coating sheet, but the adhesive element is formed directly and individually on the carrier sheet. In this way, a particularly thin and particularly flexible adhesion fastener can be manufactured.

[0016] In order to improve adhesion when connecting with the coating material, the side of the carrier sheet facing the coating material can be surface-treated or an adhesion promoter can be provided thereon. Depending on the type of coating material, for example when the coating material is polysiloxane, it may be necessary to make it difficult for the coating material to connect with other materials. Therefore, it may be advantageous to surface-treat the carrier sheet to improve adhesion, such as by plasma treatment or gas-phase fluorination. An adhesion promoter or grafting part can also be used, for example in the case of using end-group functionalized silanes, or an adhesion promoter layer can be used.

[0017] In another variant, after the adhesion element is formed, the coating material is hardened by heat, such as by thermal radiation, by light, preferably by UV light, and / or by air humidity. The coating material is usually a molding material (Abformmasse), especially a crosslinkable molding material. Depending on the type of coating material used, it is necessary to harden the coating material by crosslinking molecules or molecular chains. The hardening can be carried out by heating the forming tool, such as a forming roller, or this can facilitate the hardening. However, it is also possible that, usually after the adhesion latch is demolded from the forming tool, the hardening is achieved by heat, by light, such as by UV light, and / or by the air humidity of the ambient air. The coating material can also be appropriately pretreated for hardening, for example, by including a catalyst, such as platinum, in the coating material or mixing it with the coating material. This is the case, for example, for a coating material in the form of a two-component silicone rubber, which vulcanizes and hardens at this time due to the catalyst.

[0018] In another variant, the carrier sheet has a thickness of 10 mm or less, preferably 60 µm or less, and particularly preferably 40 µm or less. In order to save materials during manufacturing and to prevent the adhesion latch from having excessive rigidity, the carrier sheet should generally have a small thickness. However, the thickness of the carrier sheet should not be chosen too small and is usually about 25 µm or more. The thinner carrier sheet is flexible and, for example, in the case where the forming tool has a strip-shaped forming screen (see below), it facilitates the forming of the adhesion element in the forming cavity of the forming tool.

[0019] In another variant, the carrier sheet is configured as a flexible element, preferably as a film, in particular as a film for carrying information, or as a rigid element. The carrier sheet can be a flexible, compliant and preferably inelastic element or a rigid element. The carrier sheet can in particular be a film configured as elastic, plastic or inelastic. The carrier sheet in the form of a film can be made, for example, of polyurethane (PUR), polytetrafluoroethylene (PET) or acrylic foam. The carrier sheet can in particular be a film for carrying information, such as the film described in DE102020004438A1, the entire content of which is incorporated herein by reference. The film for carrying information can, for example, be color-printed, printed with an imprint, for example printed with a symbol, preferably printed with text, for example for advertising purposes, can be configured as reflective, fluorescent, luminescent, matte or shiny, can be provided with sensors, for example configured as a flexible display, or configured with KI. The sensors can be embedded in the carrier sheet in order to protect the sensors from environmental influences. The carrier sheet can also be a rigid carrier sheet or a rigid element, and the adhesion element is formed on the rigid element.

[0020] The carrier sheet can be smooth or structured on the side facing away from the coating material or the coated sheet. For example, the carrier sheet can have a locking element, which can be configured, for example, in the form of a loop and can cooperate with a corresponding, for example, hook-shaped locking element of other components in the form of a hook-and-loop fastener (Klettverschluss). The carrier sheet can also have, for example, two or more layers, and a flexible material, such as a material in the form of fibers or the like, is introduced between these layers in order to adapt to a rough, curved or corrugated surface.

[0021] In another variant, the carrier sheet is supplied to the coating material, and the carrier sheet has a plurality of additional adhesion elements made of the coating material on the side facing away from the coating material, and the additional adhesion elements have end-side contact surfaces for releasably adhering to other components by adhesion. The plurality of additional adhesion elements on the side facing away from the coating material can be formed on the carrier sheet in the same manner as the adhesion elements are formed on the side of the carrier sheet facing the coating material. In this case, the carrier sheet is passed through the device for manufacturing the adhesion fastener twice, and in the two passes through the device, the respective sides of the carrier sheet are oriented oppositely.

[0022] In another variant, the carrier sheet is selected from the group consisting of: fabric, non-woven fabric, mesh, foam, in particular acrylic foam. The material of the carrier sheet is preferably selected from the group consisting of: elastomer, thermoplastic elastomer, thermoplastic, thermosetting plastic, adhesive. The carrier sheet can be configured in different ways. The carrier sheet can also be made of sustainable raw materials, such as paper, usually coated paper. In particular, the carrier sheet can be made of thermoplastic in the form of a film. This enables, for example, thermoforming of the carrier sheet or the adhesion lock by means of a deep drawing process. In this way, the adhesion elements can extend in different directions and adhere to one or more components in different directions. The material of the carrier sheet can be functionalized. For example, the material of the carrier sheet can have heat-conducting properties or a high heat conductivity. To achieve good heat conductivity, the carrier sheet can be configured, for example, as an HDPE film. In the case where the carrier sheet is a foam, the functionalization can, for example, consist in providing a flame-retardant protective material. The carrier sheet in the form of a foam or silicone material can have a large thickness, for example on the order of a few millimeters, in order to achieve adaptation to an uneven surface. The stress distribution of the adhesion lock can also be improved or the stiffness of the adhesion lock can be adjusted by means of the carrier sheet. For example, depending on the material selected for the carrier sheet, the adhesion lock may no longer be extensible. The carrier sheet does not necessarily have to be configured as a solid or continuous carrier sheet; on the contrary, the carrier sheet can have through openings or holes and be configured, for example, in the form of a mesh.

[0023] In another variant, the plastic material or coating material is selected from the group consisting of: elastomer, preferably polyurethane, polysiloxane, in particular polyethylene siloxane, thermoplastic elastomer, thermoplastic. For the manufacture of the adhesion lock, various different coating materials can be considered. In particular, polysiloxane has proven to be advantageous for the manufacture of the adhesion lock. The coating material can also have a functionalized structure. For example, particles, such as colored particles or the like, can be embedded in the coating material, for example in polysiloxane.

[0024] In another variant, the coating material is connected to the carrier sheet by coating, preferably structuring the coating material during and / or after coating. As explained above, the connection between the coating material and the carrier sheet can be achieved in the form of a coating in order to form the adhesion element on any surface. The coating can be applied to the carrier sheet in a planar manner; for this purpose, for example, an extrusion head or a corresponding nozzle can be used. The thickness of the coating material connected to the carrier sheet by coating is generally in the order of between about 50 µm and 100 µm, but can also be higher or lower than this value range. For example, the thickness of the coating material can be predefined or compensated by using a doctor blade or the like.

[0025] The coating material can be structured during and / or after coating. Structuring of the coating material can be achieved, for example, by applying the coating by means of a printing method, such as screen printing, intaglio printing, etc., in order to produce patterns, stripes, etc. For this purpose, structured rollers, spray nozzles or printing nozzles can be used, for example. It is also possible to structure the coating material after applying the coating material in the form of a coating, for example in such a way that the coating material is guided over a doctor blade or the like, which is structured and leaves the coating material in predefined areas, whereby, for example, strip-shaped or island-shaped structures can be produced.

[0026] In another variant, the forming sieve of the forming tool is strip-shaped, and in order to form the adhesion element in the forming cavities of the strip-shaped forming sieve, the carrier sheet is brought into contact with the strip-shaped forming sieve with the side facing the coating material, preferably the carrier sheet is guided along the forming sieve on the strip-shaped forming sieve. In this variant, a metal forming sieve is usually used, which is usually looped around two rollers. The coating material usually comes into contact with the strip-shaped forming sieve in the region of one of the two rollers, usually being laid onto the strip-shaped forming sieve, whereupon the coating material penetrates or flows into the forming cavities by capillary action, usually without the need to additionally apply pressure to the coating material or to the carrier sheet for this purpose. However, it has proven advantageous to compensate for the undulations of the carrier sheet or to flatten the undulations by means of a brush, broom or the like. Then, the carrier sheet with the coating material is guided along the forming sieve on the strip-shaped forming sieve, specifically on the straight section of the strip-shaped forming sieve. After the adhesion element has been formed by allowing the coating material to penetrate into the forming cavities, the coating material can be hardened, for example by means of thermal radiation or by UV light, while guiding the carrier sheet along the strip-shaped forming sieve on the forming sieve.

[0027] It has been confirmed that forming the adhesive element by means of a strip-shaped forming sieve enables a particularly robust manufacturing process, in which the parameter window is significantly larger, and which is less sensitive, especially with respect to material variations and with respect to rheological variations of the coating material, compared to forming the adhesive element by pressing the pressure roller of the forming tool against the forming roller. In this way, the speed during the forming of the adhesive element can be significantly increased and the width of the adhesive locking element can be significantly increased, since no tearing occurs during demolding even at larger widths. Furthermore, in this variant, a rigid member can be used as the carrier sheet, which is coated with the coating material and guided along the forming sieve on the strip-shaped forming sieve in order to form the adhesive element. When manufacturing using a strip-shaped forming sieve, the coating material does not get pressed into the forming cavity, but flows into the forming cavity. In this way, the manufacturing process can be implemented using equipment with significantly lower precision requirements.

[0028] According to another aspect, the object is achieved by a device of the type described above, which has another supply device for supplying the carrier sheet to the coating material, and which is configured to form the adhesive element in the forming cavity of the forming tool on the side of the carrier sheet facing the coating material. The device is preferably configured to connect the carrier sheet to the coating material, especially before the adhesive element is formed, and in particular before the carrier sheet and the coating material reach the forming tool. In this case, the coating material and the carrier sheet are already in contact with each other or connected to each other before they reach the forming tool.

[0029] The additional supply device can be configured as an unwinding device or have an unwinding device in order to unwind or unroll the carrier sheet from a roll or a drum. The supply device can also be configured to supply the carrier sheet to the forming tool via a roll or via a defined gap. For example, the coating material and the carrier sheet can be supplied to the forming tool via a defined supply gap, which extends between two rolls, where one of the two rolls forms a pressure roller that cooperates with a forming tool in the form of a forming roll, for example. By means of the supply gap or by prescribing a defined gap width for the supply gap, the coating material can be pressed against the carrier sheet, which facilitates the connection of the coating material to the carrier sheet.

[0030] The shaping tool can be configured to form a coated sheet from a coating material between a carrier sheet and an adhesive element, the coated sheet having a thickness of 2 mm or less, preferably 300 µm or less, particularly preferably 200 µm or less, very particularly preferably 50 µm or less, especially preferably 30 µm or less, and in particular 10 µm or less. As already explained above, by using a carrier sheet for manufacturing an adhesion latch, a coated sheet with a smaller thickness can be formed compared to the case without a carrier sheet.

[0031] In one embodiment, the shaping tool has a shaping roller that cooperates with a pressure tool in the form of a pressure roller to form a conveying gap between the pressure roller and the shaping roller, and the device is configured to guide the carrier sheet through the conveying gap. By specifying the height of the conveying gap between the pressure roller and the shaping roller, the thickness of the coated sheet can be predetermined, and the adhesive element is formed on the coated sheet.

[0032] In an improvement of this embodiment, the conveying gap has a height that exceeds the thickness of the carrier sheet by 2 mm or less, preferably by 300 µm or less, particularly preferably by 200 µm or less, very particularly preferably by 50 µm or less, especially preferably by 30 µm or less, and in particular by 10 µm or less, or is equal to the thickness of the carrier sheet. As already explained above, by specifying the height of the conveying gap, the thickness of the coating material can be predetermined, and the adhesive element is formed on the coating material. In the case where the height of the conveying gap is equal to the thickness of the carrier sheet, the adhesive element is formed directly on the carrier sheet, that is, a continuous coated sheet connecting the adhesive elements to each other is not formed when manufacturing the adhesion latch.

[0033] In an alternative embodiment, the shaping screen of the shaping tool is configured in a strip shape, and the device is configured to bring the carrier sheet into contact with the strip-shaped shaping screen with the side facing the coating material in order to form the adhesive element in the shaping cavity, preferably guiding the carrier sheet along the shaping screen on the strip-shaped, usually metallic shaping screen. As already explained in connection with the method above, in this way, better adhesion of the coating material and better capillary filling can be achieved compared to the case of forming the adhesive element using a shaping roller and a pressure roller. In this way, the speed during the formation of the adhesive element and the width of the manufactured adhesion latch can be significantly increased.

[0034] The device may have a hardening device for hardening the coating material after the adhesion element is formed. The hardening device is preferably configured to harden the coating material after or before the adhesion element is demolded from the forming tool. As already explained above in connection with the method, the hardening can be achieved, for example, by heat, by light, and / or by air humidity. The hardening device may have one or more heating elements, one or more heat radiators, light sources, and / or devices for increasing the air humidity in the surroundings of the adhesion fastener.

[0035] Another aspect of the invention relates to an adhesion fastener of the type described above, which is particularly manufactured according to the method described above. In this case, the adhesion element is formed on an integral coating sheet, and the coating sheet is provided on a carrier sheet, or the adhesion element is directly provided on the carrier sheet. As already explained above, the coating sheet provided on or connected to the carrier sheet of the adhesion fastener may have a smaller thickness compared to the case of an adhesion fastener without a carrier sheet. For the case where the adhesion element is directly provided on the carrier sheet, the material of the adhesion element is usually different from the material of the carrier sheet.

[0036] The coating sheet may have a thickness of, for example, 2 mm or less, preferably 300 µm or less, particularly preferably 200 µm or less, most particularly preferably 50 µm or less, especially preferably 30 µm or less, and particularly 10 µm or less. The thickness of the coating sheet may particularly be approximately 0 µm. In the latter case, the adhesion element can be directly provided on the carrier sheet.

[0037] The carrier sheet may have a thickness of 10 mm or less, preferably 60 µm or less, and particularly preferably 40 µm or less. In this way, the material requirement can be further reduced during the manufacture of the adhesion fastener.

[0038] The adhesion element may have a height of at least 20 µm, at least 30 µm, or at least 40 µm. To achieve attachment or adhesion to the smooth surface of other components, the minimum height of the adhesion element is usually necessary. The adhesion element generally has a height of not more than 800 µm, particularly not more than 150 µm. The aspect ratio of the adhesion element, that is, the ratio of the height to the width of the adhesion element, is preferably between 0.1 and 3.0.

[0039] As already explained above in connection with the method, the carrier sheet is configured as a flexible component, preferably configured as a film, particularly configured as an information-carrying film, or configured as a rigid component. The carrier sheet in the form of a film can be made of, for example, polyurethane (PUR), polytetrafluoroethylene (PET), or acrylic foam. However, the carrier sheet in the form of a film can also be made of other materials.

[0040] As already explained above, the material of the carrier sheet can, for example, be selected from the following group, which includes: fabrics, non-woven fabrics, foams, in particular acrylic foams, polyurethanes, thermoplastics.

[0041] A connecting structure, in particular an adhesive layer, can be applied to the side of the carrier sheet facing away from the coating material. The connecting structure, for example in the form of an adhesive layer, can be used to permanently connect the adhesion fastener to other components. The adhesive layer can be applied to the side of the carrier sheet facing away from the coating material after demolding from the forming tool, but it is also possible that the adhesive layer has already been applied to the side of the carrier sheet facing away from the coating material or is applied to this side when the carrier sheet is supplied to the forming tool. In particular, the carrier sheet itself can also be made of adhesive or can contain adhesive. In this case, the finished adhesion fastener can be formed in one step.

[0042] In another embodiment, the adhesion elements on the carrier sheet, specifically on the carrier surface of the carrier sheet, have at least 10,000 / cm 2 and not more than 100,000 / cm 2 , preferably at least 25,000 / cm 2 and not more than 50,000 / cm 2 surface density. In order to reliably and releasably adhere the adhesion fastener to the smooth surface of one or more other components by adhesion, the adhesion elements need to have a large surface density.

[0043] The surface density required to achieve reliable and releasable adhesion by adhesion, i.e., the number of adhesion elements per cm 2 is significantly greater than in the case of a hooking structure, which should cooperate with other hooking structures, such as with a plush material or a hook material, in order to achieve releasable adhesion.

[0044] The adhesion elements are generally constructed in a mushroom shape and have a head region on which a corresponding contact surface is formed on the end side. A stem is usually connected to the head region, and the stem transitions into a foot portion. The adhesion elements can be constructed rotationally symmetric, but this is not mandatory. The head region of the mushroom-shaped adhesion element protrudes laterally from the stem. The foot portion usually also protrudes laterally from the stem. The adhesion elements are generally constructed solid, that is, the adhesion elements do not have cavities.

[0045] In another embodiment, a plurality of additional adhesive elements made of a coating material are provided on the side of the carrier sheet opposite the adhesive element. The additional adhesive elements have end-side contact surfaces for releasably adhering to other components by adhesion. The additional adhesive elements are preferably formed on another integral coating sheet provided on the carrier sheet or directly on the carrier sheet. As already explained above in connection with the method, the additional adhesive elements can be formed on the side of the carrier sheet opposite the adhesive element by passing the carrier sheet through the device for manufacturing the adhesive latch twice with the sides of the carrier sheet oriented in opposite directions. The carrier sheet can be constructed integrally in this case, but this is not mandatory.

[0046] However, the adhesive latch having adhesive elements on both sides of the carrier sheet as described herein can also be manufactured in different ways. For example, the carrier sheet of the adhesive latch described herein can have two layers that are arranged one on top of the other. The adhesive element is formed on one layer, and the additional adhesive element is formed on the other layer. The two layers together with the corresponding adhesive elements can first be manufactured separately, for example, in the manner described above, and then combined and connected to each other. The connection between the two layers can be established, for example, through an adhesive layer.

[0047] At least some of the adhesive elements can advantageously be constructed to be the same or similar to the additional adhesive elements. In particular, the adhesive element and the additional adhesive element can be constructed to be the same. In this way, the manufacture of the double-sided acting adhesive latch can be simplified.

[0048] The adhesive element and the additional adhesive element can have the same areal density. However, it has proven advantageous for the adhesive element and the additional adhesive element to have different areal densities. In particular, the adhesive elements on the carrier surface of the carrier sheet can be provided with an areal density of 25,000 to 50,000 adhesive elements / cm 2 to 50,000 adhesive elements / cm 2 and the additional adhesive elements on the opposite carrier surface of the carrier sheet can be provided with an areal density of 15,000 to 20,000 adhesive elements / cm 2 to 20,000 adhesive elements / cm 2 of the carrier sheet. Description of the Drawings

[0049] Other advantages of the present invention can be derived from the description and the drawings. The features described above and further described can also be used separately by themselves or in any combination of multiple ones according to the present invention. The shown and described embodiments should not be understood as an exhaustive listing, but rather more as an illustration of the exemplary characteristics of the present invention.

[0050] Figure 1a Schematically shows a partially sectional view of a device for manufacturing an adhesion fastener according to the prior art;

[0051] Figure 1b Schematically shows a detail of an adhesion fastener manufactured by the device of Figure 1a ;

[0052] Figure 2a Schematically shows a partially sectional view of a device for manufacturing an adhesion fastener according to the present invention for manufacturing an adhesion fastener according to the present invention;

[0053] Figure 2b Schematically shows a detail of an adhesion fastener manufactured by the device of Figure 2a or Figure 4 ;

[0054] Figure 2c Schematically shows a further detail of an adhesion fastener manufactured by the device of Figure 2a or Figure 4 ;

[0055] Figure 3 Schematically shows a further detail of an adhesion fastener manufactured by the device of Figure 2a or Figure 4 ;

[0056] Figure 4 Schematically shows a further partially sectional view of a device for manufacturing an adhesion fastener according to the present invention for manufacturing an adhesion fastener according to the present invention. DETAILED DESCRIPTION

[0057] In the following description of the drawings, the same reference numerals are used for identical or functionally identical components.

[0058] Figure 1a Schematically shows a device 10 for manufacturing an adhesion fastener 12, by means of which a method for manufacturing an adhesion fastener 12 is carried out. The device 10 has a supply device 14 in the form of an extrusion head for supplying a coating material 16 present in a liquid or plastic state to a forming cavity 18 of a forming tool 20. The forming tool 20 has a forming roller 21 which, in order to manufacture the adhesion fastener 12, co-operates with a pressure tool in the form of a pressure roller 22 in order to manufacture the adhesion fastener 12.

[0059] The pressure roller 22 and the forming roller 21 are each driven in a direction of rotation indicated by an arcuate arrow. A conveying gap 24 is formed between the pressure roller 22 and the forming roller 21, through which the strip-shaped coating material 16 is conveyed in a conveying direction which is Figure 1ais represented by a horizontal arrow. The conveying gap 24 also serves as a forming zone and forms the coating material 16 into a coated sheet 26. Here, the side of the coating material 16 facing the forming roller is simultaneously pressed into the forming cavity 18, and an adhesion element 28 is formed from the coating material 16 in the forming cavity 18. The forming cavity 18 is provided on or formed in a forming layer in the form of a metal forming screen 30. The forming cavities 18 are arranged uniformly on the outer circumference of the forming roller 21, and the number and distribution of the forming cavities 18 of the metal forming screen 30 can in principle be freely selected.

[0060] After the adhesion element 28 is demolded from the forming tool 20, a strip-shaped adhesion latch 12 is formed. In Figure 1b a small section of the adhesion latch with the adhesion element 28 is shown. The adhesion element 28 has an end-side contact surface 32, which is used to releasably adhere to other components by adhesion force. The contact surface 32 is very small and has an area of approximately 2000 µm 2 in the shown example. The height H of the corresponding adhesion element 28 is approximately 50 µm in the shown example, but it can also be smaller or larger. For example, the height H can be in the numerical range between approximately 20 µm and approximately 100 µm. The adhesion element 28 is configured in a mushroom shape in the shown example and has a head region, on which the contact surface 32 is formed on the end side. A stem is connected to the head region, and the stem transitions into a foot portion. The head region of the adhesion element 28 protrudes laterally from the stem of the adhesion element 28.

[0061] As Figure 1b can be seen, the coated sheet 26 formed in the forming zone in the conveying gap 24 between the pressure roller 22 and the forming roller 21 has a relatively large thickness D on the order of approximately 300 µm in order to avoid tearing of the coated sheet 26 when the adhesion latch 12 is manufactured in the device 10. The adhesion latch 12 manufactured in this way has a relatively large stiffness due to the large thickness D of the coated sheet 26 and a high consumption of manufacturing material.

[0062] Figure 2a shows a device 10 for manufacturing a strip-shaped adhesion latch 12, which is different from the Figure 1a device 10 shown in that this device has another supply device 34, which is configured to supply a carrier sheet 36 to the forming tool 20. The other supply device 34 is in Figure 2aIt is configured in the form of an unwinding device not shown graphically, and the carrier sheet 36 is unwound by the unwinding device. The carrier sheet 36 and the strip-shaped coating material 16 are supplied to a forming tool 20 having a forming roller 21. Here, before the adhesive element 28 is formed in the forming cavity 18, the first side 36a of the carrier sheet 36 facing the coating material 16 adheres to the coating material 16 and is connected to the coating material 16.

[0063] The device 10 or the other supply device 34 is configured to guide the carrier sheet 36 and the coating material 16 together through the conveying gap 24. Here, the carrier sheet 36 is guided on the side of the coating material 16 facing away from the forming roller 21. In order to guide the strip-shaped coating material 16 and the carrier sheet 36 together, the device 10 has another pressure roller 38 that cooperates with the pressure roller 22 to guide the carrier sheet 36 and the coating material 16 together through the supply gap 40 between the pressure roller 22 and the other pressure roller 38. The coating material 16 is extruded onto the carrier sheet 36 through the supply gap 40, which is conducive to forming a lasting connection between the carrier sheet 36 and the coating material 16. It can be understood that the carrier sheet 36 can also be supplied to the forming tool 20 in a manner different from the one described here, for example, in the manner described below.

[0064] By disposing the coating sheet 26 on the carrier sheet 36 or by connecting the coating sheet 26 to the carrier sheet 36, the coating sheet 26 of the adhesion latch 12 can be made significantly thinner, as shown by using Figure 2a the device 10 or the adhesion latch 12 manufactured by the device 10 described below in conjunction with Figure 4 illustrated: As compared with the adhesion latch 12 shown in Figure 2b and Figure 1b In the adhesion latch 12 shown in Figure 2b the thickness D of the coating sheet 26 is about 50 µm or less, for example, 30 µm or less, or about 10 µm or less, but it can also be larger, and is 2 mm or less, 300 µm or less, 200 µm or less, or 100 µm or less. The thickness d of the carrier sheet 36 is also relatively small and is about 60 µm or less, for example, 40 µm or less. The thickness d of the carrier sheet 36 should not be lower than a minimum thickness, which is related to the material of the carrier sheet 36 and is generally on the order of about 25 µm.

[0065] Figure 2cshows the adhesion lock 12, which has on the second side 36b of the carrier sheet 36 another coated sheet 26' with additional adhesion elements 28'. The another coated sheet 26' and the additional adhesion elements 28' are configured in the same manner as the coated sheet 26 and the adhesion elements 28 on the first side 36a of the carrier sheet 36. By passing the carrier sheet 36 twice through the device 10 shown in Figure 2a or in Figure 4 , the adhesion lock shown in Figure 2c is obtained, where, during the two passes through the device 10, the two sides 36a, 36b of the carrier sheet 36 are oriented oppositely. The double-sided acting adhesion lock 12 shown in Figure 2c can also have a carrier sheet 26 with two superposed layers, which two layers have the adhesion elements 28 or the additional adhesion elements 28'. These two layers of such a carrier sheet 26 can be connected to each other, for example, by an adhesive layer.

[0066] In Figure 1a and in Figure 2a , in the device 10 shown, the coating material 16 is usually hardened by heat generated, for example, by the forming tool 20, by light, for example, by UV light, and / or by air humidity after the adhesion elements 28 are formed. During hardening, the molecules or molecular chains of the coating material 16 crosslink. In the example shown, the coating material 16 is a polysiloxane, but it can also be other elastomers, for example, polyurethanes. To achieve hardening, the coating material 16 can be appropriately pretreated, which can, for example, involve two-component silicone rubber. In this case, before extrusion, the liquid silicone component is mixed with a catalyst, for example, a platinum catalyst, in order to produce the coating material 16 in the form of a rubber-like substance, which substance vulcanizes or hardens after the adhesion elements 28 are formed. Thermoplastic elastomers or thermoplastics can also be used as the coating material 16.

[0067] In the example shown, the carrier sheet 36 is configured as a film, that is, the carrier sheet 36 forms a carrier film. The carrier film can carry information, but this is not mandatory. Instead of a continuous film, the carrier sheet 36 can also be configured as a rigid member. The material of the carrier sheet 36 can be a fabric, a non-woven fabric, a mesh, a foam, such as an acrylic foam, a polyurethane, an elastomer, a thermoplastic elastomer, a thermosetting plastic, or an adhesive. The carrier sheet 36 can also be made of a thermoplastic material, for example, polyethylene terephthalate (PET). In this case, the carrier sheet 36 can be thermoformed, for example, by deep drawing, which enables the adhesion elements 28 to extend in different directions and adhere in different directions.

[0068] In order to improve the (permanent) connection between the carrier sheet 36 and the coating material 16, the carrier sheet 36 may be provided with an adhesion promoter, for example an adhesion promoter layer, on its first side 36a facing the coating material 16, or the said first side 36a of the carrier sheet 36 may be surface-treated. In principle, the carrier sheet 36 may be releasably connected to the coating material 16, in particular peelably releasably, so that after the adhesion element 28 is demolded from the forming cavity 18 of the forming tool 20, the carrier sheet 36 may be separated from or peeled off the coating sheet 26. The carrier sheet 36 is only used in this case to prevent the coating material 16 from tearing during the manufacture of the adhesion fastener 12, so that a coating sheet 26 with a smaller thickness D can be manufactured compared to the cases described in conjunction Figure 1a with FIGS. b.

[0069] The thickness D of the coating sheet 26 is basically determined by the height h of the conveying gap 24 between the pressure roller 22 and the forming roller 21. In order to form a coating sheet 26 with the thickness D given above, the height h of the conveying gap 24 should exceed the thickness d of the carrier sheet 36 by 2 mm or less, by 300 µm or less, by 200 µm or less, by 100 µm or less, by 50 µm or less, by 30 µm or less or by 10 µm or less.

[0070] The height h of the said conveying gap 24 may also be basically equal to the thickness d of the carrier sheet 36. In this case, the adhesion element 28 is directly and individually formed on the carrier sheet 36, as shown in Figure 3 . On the second side 36b of the coating material 16 facing away from the adhesion element 28, a connection structure in the form of, for example, an adhesive layer 42 may be applied to the carrier sheet 36, as also shown in Figure 3 . The adhesive layer 42 enables the adhesion fastener 13 to be permanently connected to other components, which are not shown graphically in Figure 3 .

[0071] In Figure 2b and Figure 3 , the adhesion element 28 of the adhesion fastener 12 shown can be releasably adhered to other components with a smooth surface on the contact surface 32 by adhesion force, and the said other components are not shown in the figures. In order to achieve reliable releasable adhesion of the adhesion fastener 12 on the smooth surface of other components, Figure 2b and Figure 3 the adhesion element 28 on the carrier sheet 36 has a surface density of at least 10,000 / cm² and not more than 100,000 / cm², usually at least 25,000 / cm² and not more than 50,000 / cm². Figure 2cThe adhesion element 28 of the adhesion latch 12 has a surface density of at least 25,000 per cm² and not more than 50,000 per cm², Figure 2c The further adhesion element 28' of the adhesion latch 12 has a surface density of at least 15,000 per cm² and not more than 20,000 per cm².

[0072] It is understood that the adhesion latch 12 can also be manufactured in a manner different from that described above. For example, instead of using a forming tool 20 with one forming roller 21, a forming tool with two or more forming rollers can be used.

[0073] Figure 4 There is shown a device 10 for manufacturing an adhesion latch 13, which mainly differs from the device shown in Figure 2a in that the forming sieve 30 of metal is configured as a strip and is wound around a first roller 44 and a second roller 46. The spacing between these two rollers 44, 46 is selected such that the forming sieve 30 is tensioned, so that a straight section of the forming sieve 30 is formed between the two rollers 44, 46, and this section faces the coating material 16. The carrier sheet 36 comes into contact with the strip-shaped forming sieve 30 in the region of the first roller 44 with its side 36a facing the coating material 16, specifically by being laid onto the strip-shaped forming sieve 30. At this time, the coating material 16 flows into the forming cavities 18 of the strip-shaped forming sieve 30 by capillary action, whereby the adhesion elements 28 are formed in the forming cavities 18. Here, the carrier sheet 36 is supplied to the forming sieve 30 parallel to the straight section, and the straight section forms the upper side of the forming tool 20. A brush-like member 48 presses against the side 36b of the carrier sheet 36 facing away from the coating material 16 in order to flatten the carrier sheet or compensate for the undulations of the carrier sheet.

[0074] The carrier sheet 36 and thus also the coating material 16 are guided along the straight section of the strip-shaped forming sieve 30, and the coating material 16 is demolded from the forming sieve 30 in the region of the second roller 46. At this time, a strip-shaped adhesion latch 12 is formed. After the adhesion elements 28 are formed by the infiltration of the coating material into the forming cavities 18 of the forming sieve 30, when being guided along the carrier sheet 36, the coating material 16 is hardened by a hardening device 50, which has a plurality of heat radiators 52, and the heat radiators are arranged on both sides 36a, 36b of the carrier sheet 36 in the region of the straight section of the forming sieve 30. The heat radiators 52 emit IR radiation into the coating material 16 in order to harden the coating material.

[0075] In Figure 4 the device 10 shown in Figure 2aAs in [description], the coating material 16 is supplied to the forming tool 20 by a supply device in the form of an extrusion head 14. The carrier sheet 36 is then coated with the coating material 16. Here, the coating height B is determined by a doctor blade 54, which is used to level the coating material 16. Usually, the coating height B of the coating material 16 is in the order of magnitude between about 50 µm and 150 µm. Before supplying the coating material 16 to the forming tool 20, the coating material 16 can be structured during coating or the coating material 16 can be structured after coating. List of reference numerals

[0076] 10 Device

[0077] 12 Adhesion lock

[0078] 14 Supply device

[0079] 16 Coating material

[0080] 18 Forming cavity

[0081] 20 Forming tool

[0082] 21 Forming roller

[0083] 22 Pressure roller

[0084] 24 Conveying gap

[0085] 26 Coating sheet

[0086] 26' Another coating sheet

[0087] 28 Adhesion element

[0088] 28' Another adhesion element

[0089] 30 Forming screen

[0090] 32 Contact surface

[0091] 34 Another supply device

[0092] 36 Carrier sheet

[0093] 36a First side of the carrier sheet

[0094] 36b Second side of the carrier sheet

[0095] 38 Another pressure roller

[0096] 40 Supply gap

[0097] 42 Adhesive layer

[0098] 44 First roller

[0099] 46 Second roller

[0100] 48 brush pieces

[0101] 50 hardening device

[0102] 52 heat radiator

[0103] 54 squeegee.

Claims

1. A method for producing an adhesive fastening part (12), the adhesive fastening part having a plurality of adhesive elements (28), the adhesive elements having end-side contact surfaces (32) for being releasably adhered to other components by means of adhesive forces, the adhesive elements (28) being formed from a coating material (16) in a forming cavity (18) of a forming screen (30) of a forming tool (20), characterized in that: A carrier sheet (36) is supplied to the coating material (16) and the adhesion element (38) is formed in a shaping cavity (18) of the shaping tool (20) on a side (36a) of the carrier sheet (36) facing the coating material (16), preferably the carrier sheet (36) is connected to the coating material (16) before the adhesion element (28) is formed.

2. The method according to claim 1, wherein: When the adhesion element (28) is formed, a coating sheet (26) is formed from the coating material (16) between the carrier sheet (36) and the adhesion element (28), the coating sheet having a thickness (D) of 2 mm or less, preferably 300 µm or less, particularly preferably 200 µm or less, most particularly preferably 50 µm or less, especially preferably 30 µm or less, in particular 10 µm or less.

3. The method according to claim 2, wherein: After the adhesive element (28) has been demolded from the shaping cavity (18) of the shaping tool (20), the carrier sheet (36) is separated from the coating sheet (26).

4. The method according to claim 1, wherein: The adhesion element (28) is formed directly on the side (36a) of the carrier sheet (36) facing the coating material (16).

5. A method according to any one of the preceding claims, wherein: After the adhesive element (28) has been shaped, the coating material (16) is cured by heat, by light, preferably by UV light, and / or by air humidity.

6. A method according to any one of the preceding claims, wherein: The carrier sheet ( 36 ) has a thickness (d) of 10 mm or less, preferably 60 μm or less, particularly preferably 40 μm or less.

7. A method according to any one of the preceding claims, wherein: The carrier sheet (36) is designed as a flexible component, preferably as a film, in particular as an information-carrying film, or as a rigid component.

8. A method according to any one of the preceding claims, wherein: The carrier sheet (36) is selected from the group consisting of: fabric, non-woven fabric, mesh, foam, in particular acrylic foam.

9. A method according to any one of the preceding claims, wherein: The coating material (16) is supplied with a carrier sheet (36) which has, on a side (36b) facing away from the coating material (16), a plurality of further adhesive elements (28') made of the coating material (16), the further adhesive elements having end-side contact surfaces (32) for releasably adhering to other components by means of adhesive forces.

10. A method according to any one of the preceding claims, wherein: The material of the carrier sheet is selected from the following group, the group comprising: polyurethane, elastomer, thermoplastic elastomer, thermoplastic plastic, thermosetting plastic, adhesive.

11. A method according to any one of the preceding claims, wherein: The coating material (16) is selected from the group consisting of: elastomers, preferably polyurethanes, polysiloxanes, in particular polyvinylsiloxanes, thermoplastic elastomers, thermoplastics.

12. A method according to any one of the preceding claims, wherein: The coating material (16) is connected to the carrier sheet (36) by coating, and the coating material (16) is preferably structured during and / or after coating.

13. A method according to any one of the preceding claims, wherein: The forming screen (30) of the forming tool (20) is strip-shaped, and in order to form the adhesive element (28), the carrier sheet (36) is brought into contact with the strip-shaped forming screen (30) with the side (36a) facing the coating material (16), and the carrier sheet is preferably guided along the strip-shaped forming screen (30).

14. A device (10) for producing an adhesive closure (12), in particular for carrying out the method according to any one of the preceding claims, comprising: a forming tool (20) having a forming screen (30) in which a forming cavity (18) is formed, a supply device (14) for supplying coating material (16) to a shaping cavity (18) of the shaping tool (20), the shaping cavity being designed for shaping a plurality of adhesion elements (28) having end-side contact surfaces (32) for releasably adhering to other components by means of adhesive forces, It is characterized in that A further supply device (34) is provided for supplying a carrier sheet (36) to the coating material (16), the device being configured to shape the adhesion element (28) in a forming cavity (18) of the forming tool on a side (36a) of the carrier sheet (36) facing the coating material (16), and the device being preferably configured to connect the carrier sheet (36) to the coating material (16) before the adhesion element (28) is formed.

15. The device according to claim 14, wherein: The forming tool (20) has a forming roller (21) which cooperates with a pressure tool in the form of a pressure roller (22), a conveying gap (24) being formed between the pressure roller (22) and the forming roller (20), and the device (10) is designed to guide the carrier sheet (36) through the conveying gap (24).

16. The device according to claim 15, wherein: The conveying gap (24) has a height (h) which exceeds the thickness (d) of the carrier sheet (36) by 2 mm or less, preferably by 300 µm or less, particularly preferably by 200 µm or less, most particularly preferably by 50 µm or less, particularly preferably by 30 µm or less, in particular by 10 µm or less, or which is equal to the thickness of the carrier sheet (36).

17. The apparatus according to claim 14, wherein: The forming screen (30) of the forming tool (20) is designed to be strip-shaped, and the device is designed to bring the carrier sheet (36) into contact with the strip-shaped forming screen (30) with the side (36a) facing the coating material (16) in order to form the adhesion element (28) in the forming cavity (18), and preferably guide the carrier sheet (36) along the strip-shaped forming screen (30).

18. An adhesive fastener (12), in particular an adhesive fastener produced according to a method according to any one of claims 1 to 13, comprising a plurality of adhesive elements (28) made of a coating material (16), the adhesive elements having end-side contact surfaces (32) for releasably adhering to other components by means of adhesive forces, characterized in that The adhesive element (28) is formed on an integral coating sheet (26), and the coating sheet is arranged on a carrier sheet (36), or the adhesive element (28) is directly arranged on the carrier sheet (36).

19. The adhesive closure according to claim 18, wherein: The carrier sheet (36) is designed as a flexible component, preferably as a film, in particular as an information-carrying film, or as a rigid component.

20. The adhesive closure according to claim 18 or 19, wherein: The adhesive elements (28) on the carrier sheet (36) have a density of at least 10,000 per cm 2 And no more than 100,000 pieces / cm 2 , preferably at least 25000 / cm 2 And no more than 50,000 pieces / cm 2 Surface density.

21. The adhesive closure according to claim 18, wherein: A plurality of further adhesive elements (28') made of a coating material (16) are arranged on a side surface (36b) of the carrier sheet (36) opposite to the adhesive element (28), the further adhesive elements having end-side contact surfaces (32) for being releasably adhered to other components by means of adhesion forces, the further adhesive elements (28') being preferably formed on another integral coating sheet (26') arranged on the carrier sheet (36) or being arranged directly on the carrier sheet (36).

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