Device for selectively applying adhesives, method for coating workpieces, coated workpiece, and use thereof

Abstract

The present invention relates to a device (1) for selectively applying adhesive onto a material, the device comprising: a container (10) for accommodating adhesive; an application roller (2) for applying adhesive onto the material, wherein the application roller is designed so that an adhesive from the container is applied onto the surface of the application roller, and the adhesive thus applied is applied onto the material; and a control means(3) in order to control the layer thickness of the adhesive applied from the container onto the application roller in such a way that the profile can be adjusted variably in the axial direction of the adhesive applied onto the application roller.

Description

[0001] Device for selectively applying adhesives, method for coating workpieces, coated workpiece and use thereof

[0002] Technical area

[0003] The present invention relates to a device for selectively applying adhesive to a material. It further relates to a method for coating workpieces, a coated workpiece, and a use thereof.

[0004] State of the art

[0005] In the wood processing industry, it is common practice to bond an edge band to the narrow side of a wooden panel, for example a material. To do this, the wood material or edge band must be coated with an adhesive. This adhesive can be used to attach the strip-like coating material to the narrow surface. This bond is typically created using a molten hot melt adhesive, which is melted within an application unit and applied to the substrates to be joined using an application roller. Depending on the specific application and the required quality of the adhesive bond, the workpieces made of wood or wood-like materials (e.g. MDE, HDF, chipboard, etc.) are coated with an adhesive from a specially designed cluster (e.g. EVA, PUR, PP, APAO, etc.).

[0006] In the applicant's continuous-feed technology, wetting occurs primarily on the narrow surface of the workpiece, whereas in the applicant's stationary technology, it is mainly the coating material itself that is wetted. The application unit is designed in such a way that it can coat different panel heights. The adhesive is always applied over the entire surface to be coated, with the layer thickness being adjusted using a dosing device. The layer thickness is reduced by decreasing the distance between the dosing device and the application roller. To increase the layer thickness, the distance is increased.

[0007] State of the art, which is the background for the present invention, is disclosed in DE 10 2005 061 245 B3, EP 3 978 142 A1, DE 10 2019 110 567 A1, DE 10 2016 123 416 A1, EP 2 335 891 A1 and DE 10 2019 106 642 A1.

[0008] Description of the invention

[0009] To reduce adhesive consumption, and also due to the sharply rising and / or volatile trading prices of the raw materials required for the production of adhesives, there is a need to reduce adhesive consumption without significantly impairing the quality of the adhesive bond. The inventors envision applying the adhesive no longer over the entire surface of the narrow side or the coating material, but instead only selectively, or not at all, in the area of ​​the center layer of the workpiece, for example.

[0010] Reducing adhesive consumption is also very important in light of the European Green Deal. The lower material usage also reduces material costs, while allowing for targeted quality improvements. Furthermore, tool and machine contamination is reduced, thereby increasing machine availability and reducing workpiece scrap and subsequent cleaning.

[0011] With this in mind, the inventors have developed a device which enables the selective application of adhesive to a material while at the same time being easy to implement.

[0012] The invention is defined by claim 1. Preferred embodiments are defined in the dependent claims.

[0013] According to the invention, a device for the selective application of adhesives to a material is claimed. The material can be the plate to be coated, but can also be the typically strip-shaped coating material. Selective application is an application in which the application thickness of adhesives can be controlled by the user as desired. An adhesive is a means which leads to an adhesive bond between the plate material and the coating material and which can also be referred to as an adhesive.

[0014] The device comprises a container for holding adhesive. This container contains an adhesive in a state in which it can be applied to the material. In particular, such a container can also comprise a heating device to keep any adhesive that may be melted in its molten and thus liquid form.

[0015] Furthermore, the device according to the invention comprises an application roller for applying adhesives to the material. Such an application roller can penetrate at least partially into the container for holding adhesive, so that its outer surface can be wetted with the adhesive. The adhesive can then be applied to the material via this application roller. For example, this application roller is provided on the outer surface of the device so that it can roll on the material and thus apply the adhesive to it.

[0016] According to the invention, the device has a control means. The layer thickness of the adhesive wetting the application roller is controlled via this control means. The control is such that the thickness profile of the adhesive wetting the application roller can be variably adjusted along the axial direction. The profile here means the layer thickness of the adhesive as a function of the position along the axial direction of the application roller. The profile can change during application, so that, for example, a profile can be used on the top and bottom edges of a panel material and also on the front and rear edges, in which a comparatively large amount of adhesive is applied over the entire length or width of the edge, while, for example, less adhesive is applied inside the edge to be coated.Mathematically speaking, the profile is the thickness of the applied adhesive layer as a function of the axial direction of the application roller. This function is variable and, in particular, is not constant over time, i.e., it can change during the adhesive application process.

[0017] A corresponding device provides a device for the selective application of adhesive to a material which is flexible in the amount of adhesive applied and which can also be retrofitted to existing machines relatively easily. The use of an application roller also creates a more continuous adhesive surface than would be the case with prior art, in which the adhesive is applied in droplet form in a modification of the liquid application process used in inkjet printers. Furthermore, no comparatively expensive piezo drives are required to generate such droplets. The control of this device is also relatively simple. Furthermore, the device according to the invention can reduce the amount of adhesive required, which leads to a reduction in costs and also avoids unnecessary use of materials, which is advantageous in terms of environmental friendliness.The amount of adhesive can also be increased selectively if necessary in order to achieve a particularly good bond at certain points.

[0018] According to the invention, the control means has a plurality of segments which are arranged along the axial direction of the application roller and can locally adjust the thickness of the adhesive application independently of one another. These segments define, with the application roller, a gap section whose thickness can be controlled. The layer thickness of the wetting adhesive can be locally adjusted via the thickness of this gap section. Such segments can be used to achieve very flexible control of the device, since the segments can be selectively controlled and thus the thickness of the gap section can be adjusted as desired at specific points along the application roller.

[0019] Preferably, one or more, preferably all, segments have a gap-forming section that is movable relative to the application roller and, together with the application roller, defines the gap that is separated from the rest of the segments. This allows the profile to be adjusted particularly well.

[0020] Preferably, the gap-forming sections are biased in a direction that maximizes the gap thickness. This would result in the device having a rest position in which the gap is maximized and thus a large amount of adhesive is applied to the application roller. This facilitates the control of the device, since no separate actuation is required to maximize the gap.

[0021] Particularly preferably, the gap-forming sections are connected to the rest of the segments via a solid-state joint. This simplifies the design of the segments.

[0022] Alternatively, the segments can be pivoted as a whole about an axis parallel to the axial direction of the application roller. This design allows the structure of the segments to be simplified.

[0023] Preferably, the segments are arranged with an axial spacing of less than 1 mm, preferably less than 0.1 mm, and most preferably without a gap. This allows the thickness of the adhesive to be controlled over the entire length of the application roller without large gaps, thus enabling a particularly uniform profile adjustment.

[0024] Furthermore, a configuration is preferred in which the control means has a control roller whose axial direction is substantially parallel to the axial direction of the application roller. This control roller has a cylindrical surface from which webs extend. The diameter and the arrangement of the cylindrical surface are selected such that a gap is defined between the cylindrical surface and the surface of the application roller, which gap enables adhesives to be applied to the application roller. The control roller can be rotated about its axis so that the one or more webs are opposite the application roller in order to thus reduce the thickness of the gap. The one or more webs have different lengths in the axial direction, with one length preferably being used for a specific board thickness. The length of the webs is preferably less than the height of the board material to be coated.The webs are preferably located in the interior of the narrow surface to be coated. By varying the center distance between the control roller and the application roller, the gap thickness can be selectively reduced, thereby reducing the amount of adhesive applied to the application roller. Such a design is easier to implement than the multi-segment design, but is less flexible.

[0025] Preferably, the one or more webs are helically shaped, at least in part, and preferably entirely. This allows a wave-shaped pattern of adhesive to be applied.

[0026] The device is preferably designed so that an adhesive is continuously applied to the outer edges of the material in relation to the axial direction. When the application roller is therefore rolled over an edge of a workpiece to be coated in order to apply adhesive to this, an adhesive is applied continuously and in particular with a constant thickness to the outer edges in the axial direction. This is advantageous in that this edge of the workpiece, which will be on the outside during use, will have a particularly high adhesive strength and will therefore be unlikely to come loose. This increases the quality of the workpiece coated in this way and also prevents foreign substances such as moisture from penetrating the coated workpiece.

[0027] It is also preferred that the device is designed such that the material is moved relative to the device along a rolling direction of the application roller, and that the adhesive is applied continuously and, in particular, with a constant layer thickness at the beginning and / or end of the workpiece in the device along the axial direction of the application roller. As a result, this end edge is also bonded with high strength, thereby increasing the quality of the workpiece.

[0028] According to the invention, a method is further claimed for coating a workpiece, which preferably consists at least in sections of wood, wood-based materials, plastics or the like, with a coating material using an adhesive. In this case, an adhesive is applied to an interface between the workpiece and the coating material in order to bond the coating material to the workpiece. The adhesive is applied to a lesser extent in a non-peripheral region (central region) of the interface than in an outer region which is closer to the circumference of the interface. As a result, adhesive can be saved in this central region without the quality of the coated workpiece produced in this way being significantly impaired.Preferably, the outer region extends to the perimeter of the interface so that the penetration of moisture and / or dirt is better prevented due to the stronger adhesion.

[0029] Preferably, the adhesive is not applied to the non-peripheral area, or is applied only in an insignificant amount. This saves a significant amount of adhesive.

[0030] Furthermore, the method preferably uses a device as described above to apply the adhesive. This leads to the advantages mentioned therein.

[0031] According to the invention, there is further provided a coated workpiece, which preferably consists at least in sections of wood, wood-based materials, plastics or the like, and a coating material provided on the workpiece. In this case, an adhesive is applied to an interface between the workpiece and the coating material in order to bond the coating material to the workpiece. The adhesive is applied to a lesser extent in a non-peripheral region of the interface than in an outer region which is closer to the circumference of the interface. As a result, adhesive can be saved in this non-peripheral region without the quality of the coated workpiece thus produced being significantly impaired. The outer region preferably extends to the circumference of the interface so that the penetration of moisture and / or dirt is better prevented due to the stronger adhesion.Such a workpiece is preferably manufactured using the method and / or device described above, which leads to the advantages described therein.

[0032] Preferably, the adhesive is not applied to the non-peripheral area, or is applied only in an insignificant amount. This saves a significant amount of adhesive.

[0033] The invention further provides for the use of a coated workpiece as described above in a piece of furnishing, preferably a piece of furniture. This results in a particularly adhesive-saving and thus cost-effective and environmentally friendly production of furnishings or pieces of furniture.

[0034] Short description of the characters

[0035] Figure 1 is a representation of a device according to the

[0036] State of the art. Figure 2 is a representation of a device according to the invention according to a first embodiment.

[0037] Figure 3 is an illustration of an embodiment according to a second embodiment of the invention.

[0038] Figures 4a) -c) are a schematic representation of the second embodiment.

[0039] Figures 4d) - f ) are a representation of a third

[0040] Embodiment of the invention.

[0041] Figures 5 and 6 represent a fourth embodiment of the invention.

[0042] Figure 7 shows adhesive application patterns that can be applied using a device according to the invention.

[0043] Detailed description of the characters

[0044] Figure 1 shows a device for applying adhesive, for example hot melt adhesive, according to the prior art. Fig. 1a) shows a view of the application roller 2 and the metering device 3. Fig. 1b) shows the device in a state in which only a little adhesive is applied, while Fig. 1c) shows the device in a state in which more adhesive is applied than in Fig. 1b).

[0045] Adhesive 10 is melted within an application unit 80 or within its container. Inside the container 80 there is an application roller 2 which can be rotated about its axis j. By being immersed in the adhesive 10 it is wetted with adhesive 10 and can apply this to a (not shown) workpiece. In this case a dosing device 3 which can be adjusted about an axis w is provided between a dosing device 3 which also projects into the container 80 and the application roller 2. By adjusting the dosing device 3 about the axis w a gap a is set between the dosing device and the application roller 2. In a first position (Figure 1b) the gap aj_ is very small so that no or only a small amount of adhesive is applied, i.e. a large part of the adhesive is retained by the dosing device 3.In a second position (Figure 1c), the gap ag is larger, so that a thicker adhesive film can be formed on the application roller 2 and transferred to the workpiece to be coated. Since the metering device 3 extends uniformly over the entire axial length h of the application roller 2, the gap size of the gap a is set uniformly over the entire height h of the application roller 2 and thus cannot be varied along the axial direction.

[0046] Figure 2 shows a device for the selective application of adhesive according to a first embodiment. The device 1 has a storage chamber 10 for receiving adhesive, which extends within the device 1. An application roller 2 extends essentially parallel to the container 10 and is immersed in the latter, so that an adhesive held by the container 10 can wet its surface. Adjacent to this application roller 2 there is provided a control means 3 which serves to control the application of adhesive to the application roller 2. The control means 3 has a plurality of segments 31, 32, which can be moved in their position relative to the application roller 2 via associated actuators 41, 42, so that the gap resulting between the segments 31, 32 and the application roller 2 can be selectively adjusted by a user.This makes it possible to control the amount of adhesive applied to the application roller 2, which in turn makes it possible to adjust the amount of adhesive applied to the workpiece to be coated. The segments 31 and 32 are shown in two different positions. The segment 31 is so close to the application roller 2 that little or no adhesive is applied to this application roller 2, while the segment 32 leaves a larger gap to the application roller 2 so that more adhesive is applied, which is also shown in Figure 2. Yet another segment results in a continuous ring of adhesive 5 being applied to the application roller 2, which ring extends around the circumference of the application roller 2 in a similar way to the continuous ring 9.In contrast, the segment assigned to region 7 essentially prevents the application of adhesive, whereas the segments assigned to segments 6 and 8 allow for intermittent adhesive application. Ring 9 corresponds to a lower edge of the workpiece to be coated.

[0047] As shown in Figure 2, the segments 31, 32 are arranged essentially without gaps or at a distance of less than 1 mm, particularly preferably less than 0.1 mm, from one another. This avoids gaps in the applied adhesive. The segments 31, 32 can be manipulated independently of one another so that they adjust the distance to the application roller and thus the thickness of the layer of adhesive transferred. The segments 31, 32 thus act as a stripping means which strips off excess adhesive from the application roller 2 so that only as much adhesive can be transferred by the rotation of the application roller 2 as is made possible by the gap between the segment 31, 32 and the application roller 2.In this case, the segments 31, 32 preferably have at least two different positions, namely an open position (segment 32) and a closed position (segment 31), wherein in the open position a higher quantity or layer thickness of adhesive is dispensed to the application roller 2 than in the closed position, in which a minimal quantity or no adhesive at all is dispensed to the application roller 2. Preferably, however, the segments 31, 32 are also adjustable in intermediate positions, so that the quantity of adhesive to be dispensed can be regulated not only in binary terms, but also with intermediate values ​​between the maximum and the minimum value.

[0048] According to the first embodiment, the dosing segments 31, 32 have a lower height b than the sheet material to be processed. Furthermore, at least one separate dosing segment 31, 32 is preferably variable in its positioning in the axial direction of the application roller 2, i.e., the workpiece height, in order to be able to process different sheet material thicknesses with a single machine.

[0049] Figure 3 shows a second embodiment of the invention. This is also schematically illustrated in Figures 4a) to c). The design is essentially similar to the design of the first embodiment, although the details of the segments are different.

[0050] As shown in the figures, the individual segments 30 have a gap-forming section 39 which is pivotally mounted with respect to a stationary section 30a via a joint 33. The gap-forming sections 39 are designed to selectively bear against the application roller 2. They are each coupled to an actuator 40 which acts on the gap-forming sections 39 via a coupling element 50. The actuators 40 are preferably designed as electrical, electromechanical, electromagnetic, piezoelectric, pneumatic and / or hydraulic actuators or combinations thereof and are provided outside the container 10. The actuators 40 are in contact with the gap forming section 39 via a coupling element 50 in such a way that a movement of the actuator 40 via the coupling element 50 produces a change in the position of the gap forming section 39, which in turn leads to a change in the gap dimension a.In this case, pressing the coupling element 50 causes the gap forming section 39 to move towards the application roller 2 and thus locally reduces the gap size.

[0051] The control of the segments 30 is shown in detail in Figure 4, with the individual steps being carried out alphabetically from a) to c). In the first position (Figure 4a)), a minimal gap ag is formed between the gap-forming section 39 and the application roller 2, so that hardly any adhesive is applied to the application roller 2.

[0052] By rotating a general dosing device 3 about its axis w, the gap-forming sections 39 of all segments 30 can now be brought into another rest position, in which the gap dimension is increased to a larger value ag (Fig. 4b). In this state, less adhesive is wiped off the application roller 2, so that more adhesive can be applied.

[0053] If the application of adhesive is to be reduced locally, the gap formation section 39 is pressed against the application roller 2 via the coupling element 50 (Fig. 1c)), whereby the gap dimension is reduced to a smaller value ag, so that the application of adhesive to the application roller 2 is reduced or prevented. Typical dimensions for the gap dimension ag are 0.1-0.2 mm, although values ​​up to 0.7 mm are also possible. The gap dimension ag can be very small and can even be 0 mm (which corresponds to a contact with the application roller 2).

[0054] In the present embodiment, the coupling element 50 is not connected to the gap-forming section 39 in a force-fitting or form-fitting manner, but merely presses against it to press the gap-forming section 39 against the application roller 2, so that the state illustrated in Figures 4a) and 4b) represents the rest state. In this respect, the elasticity of the joint 30b leads to a repositioning of the segments.

[0055] In this context, however, it is preferred that the coupling element 50 be positively, non-positively, or materially connected to the gap-forming section 39. This enables significantly more precise regulation of the gap width and thus the application thickness of the adhesive by appropriate actuation of the actuator 40. This makes it particularly possible to realize a customer-specific adhesive application by adjusting the application thickness of each individual segment 30 as desired and also makes it possible to dispense with the general dosing device 3.

[0056] In a third embodiment (Figures 4d) to f)), the dosing segment 30 is pivotally mounted about a pivot axis f, so that the entire segment, and no longer just individual parts, can be pivoted relative to the application roller 2. The function is similar to that in Figures 4a) to c).

[0057] In Figure 4d), the gap-forming section 39, i.e. the front section with respect to the pivot axis f of the segment 31, rests against the application roller 2. In the section shown in Figure 4e), all segments 30 are pivoted together with respect to the axis f, so that the gap between the application roller 2 and the segments 30 increases from aj_ to ag. In order to now reduce the gap from the larger gap ag to the smaller gap ag (see Figure 4f), pressure is exerted on the gap-forming section 39 via the coupling element 50. This leads to a deformation of the segment 30, as is shown in Figure 4f). When the pressure via the coupling element 50 is released, the segment returns to the configuration shown in Figure 4e). Such a design is particularly advantageous for the unhindered flow of adhesive within the storage chamber.Preferably, all segments 30 required for the panel material thickness used are positioned at a distance from the application roller 2 at the start and end of the workpiece so that the entire surface of the workpiece can be wetted with an adhesive over the entire height of the workpiece. The layer thickness of the adhesive is determined by the segments 30, which can be adjusted manually or automatically. The surface to be coated is wetted with the adhesive by the rotation of the application roller 2 and the simultaneous transport of the workpiece along the application roller 2. After a defined distance from the start of the workpiece, the individual dosing segments 30 are controlled as required in order to selectively prevent the transfer of adhesive from the container 10 to the application roller 2. Shortly before the rear edge of the workpiece, the entire surface of the adhesive is applied again.Adhesive is preferably always applied to the top and bottom edges and, as previously mentioned, to the front and rear edges to seal the interior of the workpiece from external influences. Within the interior of the workpiece, the adhesive application can be completely or selectively reduced by closing individual dispensing segments. Depending on the material thickness, however, individual dispensing segments can also remain open to allow individual adhesive strips to remain continuously within the workpiece, thus achieving the desired bond strength.

[0058] A fourth embodiment is shown in Figures 5 and 6. For better understanding, only the application roller 2 and the control means in the form of a control roller 38 for controlling the thickness of the adhesive application are shown in Figure 5. The application roller 2 rotates continuously about its rotation axis j, while the control roller 38, as an example of a control means, is rotated significantly less often. Both the control roller 38 and the application roller 2 are immersed in the adhesive container (not shown), so that the

[0059] Application roller 2 is wetted on its surface with the adhesive and this is applied to a workpiece to be coated

[0060] (not shown) can be applied.

[0061] As can be seen from Figure 5, two webs 35, 36 with different lengths 11, 1g are provided on the surface of the control roller 38, which project outwards. When these webs are opposite the application roller 2, they locally reduce the gap width and thus reduce or prevent the adhesive from passing through, so that the adhesive is wiped off when the application roller 2 rotates. Accordingly, less adhesive is applied locally to a workpiece. The area defined by the webs 35, 36 is preferably located in the middle region of a workpiece, so that the adhesive is applied over the entire surface of the edges of the workpiece.

[0062] The function of this fourth embodiment is shown in Figures 6a) to c). In Figure 6a), the control roller 38 is shown in a first position in which part of the surface of the control roller 38 rests against the application roller 2. This provides a minimal gap aj_ through which no or only a small amount of adhesive can penetrate. Accordingly, only a small amount of adhesive is applied to a workpiece. It can also be seen that the control roller 38 is mounted on a slide 79 which can be moved. The slide 79 itself is movably mounted on the edge 80 of the container 10 via a sealing means 78, while the mounting of the slide 79 is sealed off via a further sealing means 77.

[0063] The carriage 79 is movable along the direction m, which connects the central axes w of the control roller 38 and j of the application roller 2. With respect to the configuration shown in Figure 6a), the control roller 38 is moved slightly away from the application roller 2 via the carriage 79 in order to arrive at the configuration shown in Figure 6b). It can be seen that in this case, a surface of the control roller 38 without webs 36, 35 of the

[0064] Application roller 2 is opposite, so that here a gap ag results which is larger than the gap aj_ in Figure 6a). This allows an adhesive to pass through or less adhesive is wiped off, so that the adhesive application to a (not shown) workpiece is greater. Such an application can take place, for example, at the beginning or end of a workpiece in order to achieve a continuous and tight bond there.

[0065] To achieve the configuration shown in Figure 6c), the control roller 38 is rotated so that one of the webs 35 is opposite the application roller 2. This locally wipes off the adhesive or prevents penetration of the adhesive, resulting in a smaller (or no) application of adhesive to the application roller 2 at a local point.

[0066] If a helical web is used instead of straight webs, i.e. webs that extend along the main axis of the control roller, and the control roller rotates simultaneously with the application roller, adhesive application with a wave shape can also be realized.

[0067] The embodiment just described in Fig. 6 is easier and more cost-effective to implement due to its simpler structure and the smaller number of actuators required (only two). However, the number of webs possible on a control roller depends on the diameter of the control roller and thus on the available installation space. The first to third embodiments are therefore more flexible in their use. It is also contemplated that no adhesive is applied to the upper edge of the edge strip. This upper area is used to guide the edge strip when it is bonded. It would therefore be advisable to avoid applying adhesive here to prevent soiling of the guide. The corresponding unwetted area is removed after the edge band is bonded. This prevention of adhesive application can be prevented in the embodiment of Figures 5 and 6 by an additional web.

[0068] Figure 7 shows, in sub-figures a) to e), various designs of a pattern for applying an adhesive. An area in which a significant amount of adhesive is applied is shown in grey, while an area in which no or only significantly less adhesive is applied is shown in white. As shown in Figure 7a), it is possible for adhesive to be applied only to the edges of a narrow side, while no adhesive is applied in the middle. Such a process saves adhesive.

[0069] In Figure 7b, however, a central web along the longitudinal direction of the edge is also provided with adhesive. This design saves adhesive but still results in high bond strength.

[0070] Alternatively, adhesive-free areas can be formed intermittently in the central region of the edge, as shown in Figures 7c and 7d. In this case, the adhesive-free areas in Figure 7d are significantly larger. Such a design can ensure high adhesive strength, while at the same time, adhesive can be saved by leaving the free areas in the center. Figure 7e illustrates that significantly more complex patterns can also be formed.

[0071] In principle, the invention can be used for various types of adhesives, not just hot melt adhesives. For complex contours, it is advisable to apply the adhesive to the edge band itself, while for straight contours, it may be appropriate to apply the adhesive to the workpiece to be coated. It is also possible to increase the amount of adhesive locally to achieve a particularly high bond quality there.

Claims

Claims 1. Device (1) for selectively applying adhesive to a material, comprising: a container (10) for holding adhesive, an application roller (2) for applying adhesive to the material, wherein the application roller (2) is designed such that an adhesive is applied from the container to its surface and the adhesive thus applied is applied to the material, a control means (3) for controlling the layer thickness of the adhesive applied from the container to the application roller such that the profile in the axial direction of the adhesive applied to the application roller (2) can be variably adjusted.

2. Device according to claim 1, wherein the control means comprises a plurality of segments (31, 32) which are arranged along the axial direction of the application roller (2) and define a gap section with the application roller (2) which is controllable in its thickness, the layer thickness of the applied adhesive being controlled via the thickness of the gap section.

3. Device according to claim 2, wherein one or more, preferably all segments (31, 32) each have a gap-forming section (39) which is provided so as to be movable with respect to the application roller (2) and defines the gap with the application roller, wherein the gap-forming sections (39) are preferably prestressed in a direction in which the gap section is minimized in its thickness.

4. Device according to claim 2, wherein the segments as a whole are each pivotable about an axis (f) which is parallel to the axial direction of the application roller (2).

5. Device according to one of claims 2 to 4, wherein the segments (31, 32) are arranged with an axial distance from one another of less than 1 mm, preferably less than 0.1 mm and most preferably without a gap.

6. Device according to claim 1, wherein the control means comprises a control roller (38) whose axial direction (w) is substantially parallel to the axial direction (j) of the application roller (2), wherein the control roller has a cylindrical surface from which one or more webs (35, 36) extend, wherein the diameter of the cylindrical surface is selected such that a gap is defined between the cylindrical surface and the surface of the application roller, which gap enables application of adhesive to the application roller, wherein the control roller (38) can be selectively rotated about its axis so that the one or more webs (35, 36) are opposite the application roller in order to at least partially reduce or close the gap between the control roller and the application roller in order to reduce the application of adhesive to the application roller (2).

7. Device according to claim 6, wherein the one or more webs (35, 36) are wave-shaped.

8. Device according to one of the preceding claims, wherein the device is designed such that an adhesive is continuously applied to the outer edges of the material with respect to the axial direction.

9. Device according to one of the preceding claims, wherein the device is designed such that the material is moved with respect to the device along a rolling direction of the application roller and that at the beginning and / or end of the material in the unrolling direction the adhesive is continuously applied along the axial direction of the application roller.

10. A method for coating a workpiece, which preferably consists at least in sections of wood, wood materials, plastics or the like, with a coating material using an adhesive which is applied to an interface between the workpiece and the coating material, wherein the adhesive is applied to a lesser extent in a non-peripheral region of the interface than in a region which is closer to the circumference of the interface than the non-peripheral region.

11. The method according to claim 10, wherein the adhesive is not applied or is applied only in an insignificant amount in the non-peripheral region.

12. A method according to any one of claims 10 to 11, wherein the method uses a device according to any one of claims 1 to 9 for applying the adhesive.

13. Coated workpiece with a workpiece, which preferably consists at least in sections of wood, wood materials, plastics or the like, and a coating material fastened to the workpiece, wherein the coating material is connected to the workpiece via an adhesive, wherein the adhesive is applied to an interface between the workpiece and the coating material and wherein the adhesive is applied to a lesser extent in a non-peripheral region of the interface than in a region which is closer to the circumference of the interface than the non-peripheral region, wherein the workpiece was preferably produced using a method according to one of claims 10 to 12 and / or using a device according to one of claims 1 to 9 for applying the adhesive. 14 . Coated workpiece according to claim 13 , wherein the adhesive is not applied or is applied only in an insignificant amount in the non-peripheral area . 15 . Use of a coated workpiece according to one of the Claims 13 to 14 in a piece of furniture, preferably a piece of furniture.

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