Method for coating a metal drawer frame with veneer

Abstract

A method for coating a metal drawer front (1) with veneer (2), comprising the following process steps: providing an elongated, U-shaped casing part (4) with a back section (4.r) having a width (b) corresponding to the width (B) of the upper longitudinal edge (1.r) of the front (1), and two side sections (4.1, 4.2) of veneer extending substantially parallel to each other from the back section, the side sections having a height (h) corresponding substantially to the height (H) of the front (1) and a length (l) corresponding substantially to the length (L) of the front (1), wherein the facing inner surfaces of the side sections (4.1i, 4.2i) have an adhesive section (6.1, 6.2) extending over a portion of the height h of each side section (4.1, 4.2) containing a thermally post-curing adhesive and optionally a spacer between the adhesive section (6.1, 6.2) and the adhesive-free transition section (8.) arranged in the back section (4.r).1, 8.2), applying adhesive (10), in particular liquid adhesive, a heat-reactivated or a thermally post-curing adhesive, to the upper longitudinal edge (1.r) of the frame (1) or to the inner side (4.ri) of the back section (4.r) of the sheathing part (4), spreading open the free ends (4.1.a, 4.2.a) of the side sections (4.1, 4.2) of the sheathing part (4), placing the spread-open sheathing part (4) onto the upper longitudinal edge (1.r) of the frame (1) and moving the free ends (4.1a, 4.2a) of the side sections (4.1, 4.2) of the sheathing part (4) towards each other, such that the adhesive sections (6.1, 6.2) on the inner surfaces (4.1i, 4.2i) of the first and second Side sections (4.1, 4.2) are in contact with the outer surface (1.1, 1.2) of the frame (1), and the thermally crosslinkable adhesive in the adhesive sections (6.1, 6.2) of the adhesive (10) is cured, preferably by inductive heating of the frame.

Description

[0001] The invention relates to a method for coating a metal drawer frame with veneer according to the preamble of claim 1.

[0002] It is known from the prior art to use drawers or drawer boxes in furniture, particularly kitchen and office furniture, which, for cost reasons, are not made of solid wood but instead use side and back steel frames. These frames are connected to the front and back panels by screws or plug-in connections and form the basic body of the drawer box. These steel frame systems are frequently pre-assembled in automated assembly processes in the kitchen furniture industry and then inserted into the kitchen cabinets.

[0003] However, for the upper price segment, there is increasing demand for higher-quality solutions, particularly wooden drawers, the production of which involves considerably more complex logistics compared to steel drawer systems. Furthermore, wooden drawers require the use of technically different runner systems, resulting in significant cost disadvantages due to the associated design changes and the considerably higher assembly effort.

[0004] Therefore, wooden drawer systems are constantly being developed that offer a degree of compatibility with certain steel drawer frames, making them easier to integrate into the industrial processes of kitchen furniture manufacturing than traditional solid wood drawers. However, the systems currently available on the market only partially meet this requirement, as the functionality of steel drawer frames is difficult to achieve with a wooden or wood-based panel frame.

[0005] From DE 202013 011 U1, which discloses the preamble of claim 1, a method for cladding furniture components, such as metal drawer sides, is known, in which veneer is attached to the base body of the furniture component at a defined point using adhesive strips. The document makes no mention of placing a prefabricated veneer covering part, comprising a back section and two side sections extending substantially parallel to each other and coated on their inner surfaces with a thermally curable hot melt adhesive, onto the side to be coated and first melting and then thermally curing the adhesive by applying heat.

[0006] Furthermore, GB 141 202 discloses a method for coating objects with veneer, in which the adhesive-coated veneer and the object to be coated are pressed together against the outside of a box-shaped container using clamps. The hollow interior of this container is heated with introduced hot steam to warm the outer surfaces of the box. The document also provides no information on the coating of a metal drawer frame with veneer, in which a prefabricated, U-shaped cover is placed on the frame and bonded to it using a thermally curing hot melt adhesive applied to the inner surfaces of the cover.

[0007] Accordingly, it is an object of the present invention to provide a method by which industrially manufactured steel drawer systems can be modified with minimal effort while retaining their production-related advantages in such a way that their external appearance corresponds to that of a wooden drawer.

[0008] This problem is solved according to the invention by a method having the features of claim 1.

[0009] Another object of the invention is to provide a covering part and its use with which the frames, in particular metal frames of a steel frame drawer system, can be adapted to the optical appearance of frames of a wooden drawer with minimal effort.

[0010] This problem is solved according to the invention by a sheathing part and a use thereof with the features of claims 14 and 15.

[0011] According to the invention, the method according to the invention comprises the following process steps: Providing an elongated, U-shaped cladding section with a back section having a width corresponding to the width of the upper longitudinal edge of the frame, and two veneer side sections extending substantially parallel to each other from this back section, the side sections having a height and length corresponding substantially to the height and length of the frame, wherein the facing inner surfaces of the side sections have an adhesive section extending at least over a portion of the height of each side section with a thermally curable adhesive and optionally an adhesive-free transition section arranged between the adhesive section and the back section, applying further adhesive, in particular liquid adhesive, a heat-reactivated and / or a thermally curable adhesive,on the upper longitudinal edge of the frame or on the inside of the back section of the casing part, spread open the free ends of the side sections of the casing part, place the spread-open casing part onto the upper longitudinal edge of the frame, move the free ends of the side sections of the casing part towards each other, so that the adhesive sections on the inner surfaces of the first and second side sections are in contact with the outer surface of the frame, and cure the thermally post-curing adhesive in the adhesive sections by heating the frame.

[0012] The drawers manufactured using the method according to the invention have the advantage that they have a very appealing real wood appearance, and the drawers produced in this way are perceived by users as particularly high-quality wooden drawers in contrast to expressionless, monochrome steel frames.

[0013] Another advantage of the solution according to the invention is that the veneer-coated drawer systems can be assembled cost-effectively and at high production speeds using the equipment available in the industry, in the same way as is usual for steel-frame drawer systems.

[0014] The advantage of the inventive method lies in the manufacturing process itself, since the known steel frames cannot be covered using the classic methods of veneering.

[0015] The side panels / frames are made of sheet steel constructions with integrated functional elements. This allows, for example, for the front panel to snap into place easily, as well as height, side and tilt adjustment, and simple assembly of the drawer after coating with the cladding part.

[0016] According to the invention, suitable coating materials, such as wood veneers or covering materials such as leather, linoleum, and laminates with which the frame is to be coated, are preferably coated as bellows or roll goods with an adhesive substrate, for example, with a double-sided adhesive film, the outer adhesive surface of which is covered after application in a known manner by a removable protective film. In a particularly preferred embodiment of the method, the wood veneers are coated over their entire surface with a thermally post-curing hot melt adhesive, which, for example, has a melting temperature of preferably 50°C and which can be thermally post-cured by heating to a cross-linking temperature of preferably 70°C. Such a hot melt adhesive in the form of a double-sided heat-activated adhesive film is, for example, manufactured by Lohmann GmbH & Co.KG, D-56504 Neuwied under the product name "DuploTEC 12223 SBF LTC".

[0017] The thermally post-curing hot melt adhesive can be heated to a temperature above its liquefaction temperature but below its curing temperature. In its liquefied state (and not yet fully cured), it can then be applied to the strip-shaped veneer material or veneer pieces using standard application rollers. After cooling, this results in a non-adhesive (dry) veneer piece, which can be rolled up again if desired. This non-adhesive veneer piece can then be easily processed further in conventional veneer processing stations. For example, punching and cutting can be used to precisely produce the required cutouts for the coated frame, including the individually specified openings.

[0018] Alternatively, the previously described hot melt adhesive can be applied as a dry film layer of a desired thickness to the preferably ribbon-shaped veneer material or, alternatively, to the already cut veneer pieces. It can then be partially melted by heating to a temperature above the melting point and below the curing point, and subsequently cooled again to bond the veneer piece with the thermally post-curing adhesive, or, in particular, to coat it completely. For this purpose, the hot melt adhesive has the property that the melting point and the curing point differ by at least approximately 5 °C, preferably at least approximately 10 °C, and particularly preferably approximately 20 °C.

[0019] Alternatively, the adhesive film in the bonding sections can comprise a thermosetting PU film containing a thermally post-curing adhesive in film form with a thickness of, for example, 0.05 mm, preferably wound onto a roll with a release paper, similar to double-sided adhesive tape. Such a thermosetting PU film is marketed, for example, under the brand name "DuploTec 12223 SBF LTC" by Lohmann GmbH & Co. KG in Neuwied, Germany.

[0020] This PU film is first laminated onto the veneer at a relatively low temperature, e.g., 50°C, similar to double-sided adhesive tape. The sheathing is then glued in the manner described in more detail below and, after spreading the side panels, stretched onto the metal frame. After stretching, the metal frame is heated in an oven or, alternatively, inductively for approximately 1 minute to preferably about 90°C, while the sheathing is pressed onto it. This heating raises the temperature of the thermally post-curing adhesive of the hot melt adhesive film above its curing temperature, thus initiating the curing reaction. As the applicant has found, the resulting strength and long-term durability are significantly higher than those of known double-sided adhesive tapes, whose acrylate adhesive films are known to exhibit a "cold flow" that can lead to the adhesive joints delaminating under extreme and prolonged climatic fluctuations.

[0021] As an alternative to using the heat-curing PU adhesive film, a liquid adhesive, preferably in the form of a thermally post-curing PU dispersion or a similar wet adhesive, can also be used.

[0022] The liquid adhesive is preferably sprayed onto the inside of the finished, processed cladding component via nozzles, or alternatively, rolled onto rollers and dried by exposure to air for, e.g., 30 minutes. The cladding component with the dried adhesive layer is then applied to the metal frame within approximately 4 hours. The activation of the dried liquid adhesive then occurs similarly to that of the thermosetting film by heating the frame with the attached cladding component, preferably in an oven or alternatively by inductive heating of the metal frame to a temperature that triggers the cross-linking reaction and thus the complete post-curing of the adhesive. For example, this temperature is approximately 80°C for the aforementioned PU dispersion adhesive with the brand name "JOWAPUR," which is distributed by JOWAT in Detmold, Germany.By using a liquid PU dispersion adhesive that dries through exposure to air and undergoes thermal post-curing upon heating to a cross-linking temperature of, for example, 80 °C, the need for adhesive-free areas, as required when coating with a conventional liquid adhesive, is eliminated, since the inner surface of the encapsulation part is completely coated during spraying with the liquid adhesive. This significantly simplifies the manufacturing process.

[0023] Preferably, veneers, especially wood veneers, are used as coating material. These veneers already have a largely finished surface and are supplied in rolls. For this purpose, the use of fleece-backed, sanded, primed, and / or lacquered veneers is particularly advantageous.

[0024] In the next step, precisely fitting cutouts for the coating are produced from the raw material, e.g. by punching, milling, sawing as well as laser or waterjet cutting, which have the outer dimensions of the respective outer surface of the frame to be clad, and into which the necessary openings are also made, which, after the frame has been clad, provide access to the recesses formed in it, especially for screws.

[0025] The prefabricated individual parts are then assembled into a complete, precisely fitting casing part, preferably by gluing with a thin wooden strip at the top edge to increase stability and allow for sanding.

[0026] In one embodiment of the invention, the cladding part is created by applying a layer of thermally curing adhesive, as described above, to the first and second strip-shaped veneer pieces, each of which, after trimming, has a straight top and bottom edge as well as an inner surface facing the outer surface of the frame. This creates the respective adhesive section and, optionally, an adhesive-free transition section arranged between the top edge of the respective veneer piece and the first adhesive section. The side sections of the first and second veneer pieces thus created are then bonded to the parallel side surfaces of a provided strip-shaped backing element to form the cladding part, in the area of ​​their respective straight top edges.

[0027] In the preferred embodiment of the invention, in which the two veneer parts are coated over their entire surface with the thermally post-curing hot melt adhesive applied in the manner described above, the respective first and second veneer parts are joined in the area of ​​their respective straight upper edges to the parallel side surfaces of the strip-shaped back element by placing the two veneer parts parallel to each other and pressing them against the parallel side surfaces of the strip-shaped back element in the area of ​​their straight upper edges, while simultaneously heating the first and second veneer parts to a temperature above the cross-linking temperature.In this process, the heat energy is preferably introduced exclusively in the area of ​​the strip-shaped back element, in particular in the area of ​​the parallel side surfaces of the strip-shaped back element, so that the thermally post-curing hot melt adhesive hardens exclusively in this area and joins the two veneer parts with the strip-shaped back element to form the sheathing part.

[0028] Preferably, the two parallel veneer parts are pressed against the parallel side surfaces of the strip-shaped back element by two opposing heated pressure bars, which are subjected to the required pressing pressure, e.g. by pneumatic cylinders.

[0029] The two veneer parts of the cladding part thus produced have opposing inner surfaces coated with the post-curing hot melt adhesive, in which the hot melt adhesive is no longer liquid, but advantageously not yet fully cross-linked.

[0030] Optionally, the cladding part can be formed by introducing V-shaped grooves along the upper two longitudinal edges of the cladding part on the side which forms the inner surfaces adjacent to the outside of the frame in the finished cladding part, and by folding over the two side sections of the blank which form the legs of the U-shaped cladding part in a direction orthogonal to the plane of the blank.

[0031] By using wooden strips approximately 1-3 mm thick, which can be glued to the veneer, particularly between the two V-shaped grooves, or by using veneers that are glued multiple times along the top edge, i.e., the back of the cladding section, strong, durable longitudinal edges are advantageously achieved, similar to solid wood edging on tabletops. It is beneficial to apply adhesive to the V-shaped grooves before or after folding over the side sections; once cured, this ensures that the side sections retain their orthogonal position relative to the back section.

[0032] Afterwards, the cladding component can be finished, e.g., by milling and grinding, preferably primarily on the top edge. The visible outer surfaces of the cladding component are preferably pre-finished to a largely finished surface, so that they do not require further processing.

[0033] Furthermore, it may optionally be provided that the surface of the cladding part is refined in a further step, depending on the raw material, e.g. by painting.

[0034] The finished casing is then applied to the drawer frame. To do this, any protective films are removed, and the side panels are opened, for example, using vacuum suction cups that grip the side sections and spread them apart in a V-shape.

[0035] In the preferred embodiment of the invention, a further adhesive, in particular a liquid adhesive, is applied to the upper edge of the frame before the cladding part is placed on the frame, since an adhesive film in this area would make application more difficult. This further adhesive is particularly preferably also a heat-curable liquid adhesive, which preferably has essentially the same melting and curing temperatures as the thermally curable hot melt adhesive that is applied to the inner surfaces of the first and second veneer parts as a sheet-like material in one of the previously described ways, or sprayed on as a PU dispersion adhesive, either over the entire surface or optionally leaving an adhesive-free transition section.

[0036] Alternatively, the casing part can be positioned with the back facing downwards, spread open using the vacuum suction cups, the additional adhesive applied from above to the inner surface of the back section, and then the frame inserted into the casing part from above as well.

[0037] Instead of a double-sided adhesive film, a reactive adhesive can also be applied, e.g. a hot melt adhesive, which is either hot-applied or reactivated with heat after the casing part has been placed on the frame, or thermally cross-linked in the manner described above.

[0038] Alternatively, classic wet gluing is also conceivable. In contrast to the use of an adhesive film or a thermally post-curing or reactivated adhesive and further adhesive, this embodiment of the method requires the application of a necessary pressing pressure, which necessitates a correspondingly stable frame.

[0039] The invention is described below with reference to the drawings and based on preferred embodiments of the invention.

[0040] The drawings show: Fig. 1 a schematic representation of two strip-shaped veneer parts, each with a side section formed by die-cutting, onto which double-sided adhesive tape is applied to provide the first and second adhesive sections; Fig. 2 a schematic three-dimensional representation of a sheathing part according to the invention before the side sections are glued to the back section; Fig. 3 a schematic three-dimensional representation of the finished, glued sheathing part. Fig. 2 Fig. 4 shows a schematic spatial representation of a finished, bonded cladding part during the application of a coloring or impregnating coating material, Fig. 5 shows a front view of the cladding part spread open by suction cups before being placed on a drawer front to be coated or clad, Fig. 6 shows a spatial representation of a finished coated drawer front, and Fig. 7 shows a spatial representation of a further embodiment of the invention in which the cladding part is formed from a continuous single strip-shaped veneer part, into which two V-shaped grooves are made, along which the side sections are folded in an orthogonal direction to the plane of the veneer part.

[0041] As in the Figuren 1 bis 7 As shown, it is used for coating a Fig. 5 and 6The illustrated drawer frame 1, which is preferably a metal frame, with veneer 2, initially provides an elongated, U-shaped cross-section covering part 4, which, for example, in its final form in Fig. 4 This is shown. It has a back section 4.r, which has a width b corresponding to the width B of the upper longitudinal edge 1.r of the frame 1, and two side sections 4.1, 4.2 made of veneer 2 extending substantially parallel to each other at right angles from it. The side sections 4.1, 4.2 each have a height h corresponding substantially to the height H of the frame 1 to be coated or clad and a length 1 corresponding to the length L of the frame 1.

[0042] As in the Figs. 2 , 4 and 5As can be seen, the facing inner surfaces 4.1i, 4.2i of the side sections 4.1, 4.2 are provided with an adhesive section 6.1, 6.2, which extends at least over a portion of the height h of each side section 4.1, 4.2. In the illustrated embodiment, the two side sections 4.1, 4.2 each further have an optional adhesive-free transition section 8.1, 8.2 arranged between the adhesive section 6.1, 6.2 and the back section 4.r, as shown in Fig. 1 and 2 shown.

[0043] To attach the sheathing part 4 to the frame 1 to be coated, adhesive 10, in particular liquid adhesive, a heat-reactivated or thermally post-curing adhesive or adhesive film is applied to the upper longitudinal edge 1.r of the frame 1 or to the inside 4.ri of the back section 4.r of the sheathing part 4, as shown in the sectional view of Fig. 5 as indicated.

[0044] Subsequently, the free ends 4.1.a, 4.2.a of the side sections 4.1, 4.2 of the casing part 4 are spread open and the spread-open casing part 4 is placed on the upper longitudinal edge 1.r of the frame 1, which is indicated by the unspecified arrows in Fig. 5 as indicated.

[0045] Finally, the splayed free ends 4.1a, 4.2a of the side sections 4.1, 4.2, which are preferably only schematically indicated by suction devices 20 in the spread-apart position of Fig. 5 are held and moved towards each other so that the adhesive sections 6.1, 6.2 on the inner surfaces 4.1i, 4.2i of the first and second side section 4.1, 4.2 are in contact with the respective outer surface 1.1, 1.2 of the frame 1 and are bonded to it.

[0046] To ensure particularly good adhesion of the inner surfaces 4.1i, 4.2i, even in the area of ​​the longitudinal edges of the frame 1, the frame 1, after the sheathing part 4 has been placed on the upper longitudinal edge 1.r of the frame 1, can be inserted into a vacuum chamber (not shown) with flexible side walls, in particular a sealable silicone pocket. This chamber is then sealed and pressurized with a vacuum so that all areas of the sheathing part 4 are in contact with the outside of the frame 1 with uniform pressure. Subsequently, the sealed, evacuated vacuum chamber, containing the frame 1, is heated for a predetermined period, e.g., approximately 10 minutes, to a temperature above the curing temperature of the thermally post-curing adhesive.The heating preferably takes place in a known oven and / or by irradiation with an IR heat source and / or by inductive heating of the metal frame.

[0047] After the thermally post-curing adhesive, or the further liquid adhesive 10, has cured by heating the metal frame 1 with the attached sheathing part 4 above the cross-linking temperature of, for example, 70–80°C for a period of preferably 10 minutes, which thereby polymerically cross-links in the adhesive sections 6.1 and 6.2, a Fig. 6 The illustrated frame 1, covered with veneer 2, whose metal core can be connected to the standardized front panels and back panels of the respective systems (not shown in detail) in the manner known for such industrially manufactured drawer systems by means of the usual fastening elements of the drawer systems, such as screws and / or metal hooks, to form a drawer which gives the viewer the impression of a handmade wooden drawer.

[0048] In a first embodiment of the method according to the invention, as described in Fig. 1 shown, a first and a second strip-shaped veneer part 100.1, 100.2 provided, each having a straight upper edge 102.1 and lower edge as well as an inner surface 100.1.i and 100.2.i facing the outer surface 1.1 and 1.2 of the frame 1. A first layer of adhesive 10 is then applied to this inner surface 100.1i, 100.2i of the respective strip-shaped veneer part 100.1, 100.2, either over the entire surface or, as shown, optionally at a distance from the straight upper edge 102.1, or 102.2, in such a way that the first adhesive section 6.1 and the optional first adhesive-free transition section 8.1 arranged between the upper edge 102.1 of the first veneer part 100.1 and the first adhesive section 6.1, as well as the second adhesive section 6.2 and the optional second adhesive-free transition section 8.2 arranged between the upper edge 102.2 of the second veneer part 100.2 and the second adhesive section 6.2, are formed.The optional first and second adhesive-free transition sections are preferably only provided when using self-adhesive tape or adhesive to enable precise positioning of the sheathing part 4 relative to the frame 1 after the sheathing part 4 has been placed on it.

[0049] Furthermore, a [something] will be [something] in Fig. 2 The strip-shaped back element 12 shown has an outer longitudinal section, which forms the back section 4r, and two parallel side surfaces 12.1 and 12.2 arranged at right angles to it. In the case of the optional transition sections provided, this is bonded to the respective transition section 8.1, 8.2 of the first and second veneer parts 100.1, 100.2 in the area of ​​the respective straight upper edges 102.1, 102.2 with the parallel side surfaces 12.1 and 12.2 of the strip-shaped back element 12 to form a covering part 4, as shown in Fig. 2 as indicated.

[0050] In the case of the preferably used thermally post-curing hot melt adhesive, which, for example, is applied to the veneer material over its entire surface by briefly melting and cooling a corresponding film of hot melt adhesive as described above, the bonding of the two parallel side surfaces 12.1 and 12.2 with the strip-shaped back element 12 is carried out in a particularly advantageous manner by pressing the respective first and second veneer part 100.1, 100.2 in the area of ​​the respective straight upper edges 102.1, 102.2 against the parallel side surfaces 12.1 and 12.2 of the strip-shaped back element 12 by two opposing heated pressure strips.

[0051] As the applicant discovered in this context, the thermally post-curing hot melt adhesive can be fully post-cured by the heat energy introduced through the veneer material into the hot melt adhesive layer by the heated pressure strips (not shown in detail in the drawings) exclusively in this narrow area of ​​the side surfaces 12.1 and 12.2, without visually impairing the structure and surface of the veneer material on the outside of the casing part 4. In the remaining area of ​​the adhesive sections 6.1, 6.2, however, no final cross-curing of the hot melt adhesive takes place, so that the fully bonded casing part 4, with the adhesive sections 6.1, 6.2 arranged on the inside of the veneer material (which are not tacky at room temperature), can be expanded in the manner described above and, with the addition of further adhesive, guided over the frame 1 as a single component to bond the veneer parts 100.1, 100.2 then to bond inseparably to the frame 1 by heating above the crosslinking temperature.

[0052] After gluing, the side sections 4.1, 4.2 of the U-shaped cross-section covering part 4 can be processed, if necessary, before gluing to the strip-shaped back element 12, in particular cut to the desired height and / or width and / or length and preferably provided with punched openings 14, through which, for example, the clamping elements for attaching the frame 1 to the front and back walls of the drawers can be actuated.

[0053] According to a further embodiment of the invention, it can alternatively be provided to include a Fig. 7 The continuous, single, strip-shaped veneer part 200 shown is preferably formed from roll material by appropriate cutting or punching. The continuous, strip-shaped veneer part 200 has a width that essentially corresponds to the sum of the heights h of the first and second side sections 4.1, 4.2 plus the width of the back section 4.r. A first, preferably V-shaped groove 200.1 and a second, preferably V-shaped groove 200.2 are then cut into the continuous, single, strip-shaped veneer part 200 at a distance of half the width of the back section 4.r on both sides of a central longitudinal axis 210 over the length of the single, strip-shaped veneer part 200, as shown in Fig. 7 as indicated.

[0054] Before or after the two grooves 200.1 and 200.2 are made, a first and second layer of adhesive is applied to the top side of the individual strip-shaped veneer part 200, i.e., to the side of the veneer part on which the grooves 200.1, 200.2 are made, at a distance from the first and second V-shaped groove 200.1, 200.2, which form the first and second adhesive section 6.1, 6.2 and optionally define the adhesive-free transition section 8.1, 8.2 arranged between the adhesive sections 6.1, 6.2 and the back section 4.r.

[0055] In a preferred embodiment of the invention, adhesive, in particular liquid adhesive 10, can next be applied along the first and second V-shaped grooves 200.1, 200.2, and the section of the individual strip-shaped veneer part 200 arranged outside the back section 4.r can then be folded over at a right angle to the U-shaped cladding part 4, as shown in the Fig. 7 as indicated by the dashed arrows. After the adhesive 10 has hardened, the shape-retaining casing part 4 can be removed, as shown in Fig. 3 indicated on its outer surface, smoothed and / or as desired, as in Fig. 4 shown, painted.

[0056] As the applicant has found, it is particularly advantageous with regard to simple and cost-effective manufacturing and handling of the prepared cladding parts 4 if the provision of the cladding part 4, which has a U-shaped cross-section and includes the back section 4.r corresponding to the width of the upper longitudinal edge 1.r of the frame 1 and the two side sections 4.1, 4.2 provided on their inner side 4.1i, 4.2i with a first and second adhesive layer 10.1, 10.2 respectively, made of veneer 2, is carried out by unrolling and processing strip-shaped veneer 2 rolled into a coil.

[0057] Furthermore, according to another concept underlying the invention, as previously explained, the adhesive sections 6.1, 6.2 on the first and second side sections 4.1, 4.2 can be formed by a thermally post-curing double-sided adhesive tape, the upper surface of which is preferably covered by a removable protective film after application. The double-sided adhesive tape, supplied as roll material, can be continuously applied to the upper surface of the strip-shaped veneer parts 200 during longitudinal slitting, cutting to length, and die-cutting. For this purpose, in the case of a preferably used thermally post-curing PU adhesive film, it may be provided that the veneer of the sheathing part 4 is first heated to a temperature of, for example, 50°C, which is below the cross-linking temperature of the PU material.The protective film is preferably removed before the thermally activated liquid adhesive is sprayed onto the inside of the strip-shaped back element (12). Alternatively, the protective film can be removed before the two veneer parts (100.1, 100.2) are bonded to the strip-shaped back element (12). Finally, it is also possible to remove the protective film after spreading open the free ends 4.1a, 4.2a of the side sections 4.1, 4.2 and before placing the spread-open casing part 4 onto the upper longitudinal edge 1.r of the frame 1 (. Fig. 5 to remove.

[0058] As the applicant has found, the width of the optional adhesive-free transition section 8.1, 8.2 of the first and second side sections 4.1, 4.2 is advantageously 3 mm to 20 mm, in particular 10 mm. The adhesive-free transition section 8.1, 8.2 allows the finished sheathing part 4, after the protective film has been removed from the double-sided adhesive tape, to be precisely positioned at the desired position over the frame 1 by sliding the spread-out side sections 4.1 and 4.2 back and forth. This eliminates the need for post-processing of the coated frame 1, provided the frames 1 and sheathing cables 4 are manufactured with sufficient precision. Fig. 6 ) can be omitted.

[0059] According to the presentation of Fig. 5The spreading of the free ends 4.1a, 4.2a of the side sections 4.1, 4.2 of the sheathing part 4 can be carried out by motor-operated suction devices 20, which draw in the side sections 4.1 and 4.2 and are then moved away from the frame 1 in the direction of the unspecified arrows, for example by an associated pneumatic cylinder or an electrically operated actuator (not shown).

[0060] The invention further relates to the use of a previously described cladding part 4 for use in a method described at the outset according to the invention, wherein the cladding part comprises a back section 4.r, which has a width b corresponding to the width B of the upper longitudinal edge 1.r of a frame 1 to be coated, and two side sections 4.1, 4.2 made of veneer extending substantially parallel to each other from this back section, which have a height h corresponding substantially to the height H of the frame 1 and a length 1 corresponding to the length L of the frame 1, wherein the mutually facing inner surfaces 4.1i and 4.2i of the side sections 4.1, 4.2 have an adhesive section 6.1, 6.2 extending over a part of the height of each side section 4.1, 4.2 and optionally an adhesive-free transition section 8.1, 8.2 arranged between the respective adhesive section 6.1, 6.2 and the back section 4.r.

[0061] The casing part 4 is preferably used for coating or covering a drawer frame, in particular a metal frame, for a cabinet piece of furniture, in particular a kitchen cabinet, living room cabinet, bedroom cabinet or a chest of drawers, with veneer. List of reference symbols

[0062] 1 Drawer frame 1.1 Outer surface of the frame 1.2 Outer surface of the frame 1. Upper longitudinal edge of the frame 2 Veneer 4 Wrapping part 4.1 First side section 4.2 Second side section 4.1 Inner surface of the first side section 4.2 Inner surface of the second side section 4.1 Free end of the first side section 4.2 Free end of the second side section 4. Back section 6.1 First adhesive section on inner surface of the first side section, 6.2 Second adhesive section on inner surface of the second side section 8.1 Optional adhesive-free transition section 8.2 Optional adhesive-free transition section 10 Adhesive 10.1 First adhesive layer 10.2 Second adhesive layer 12 Strip-shaped back element 12.1 First side surface (adhesive surface) of the back section 12.2 Second side surface (Adhesive surface) of the back section 14 Punch opening 20 Suction devices for opening the sheathing parts 100.1 First strip-shaped veneer part 100.1 Inner surface of the first strip-shaped veneer part 100.2 Second strip-shaped veneer part 100.2 Inner surface of the second strip-shaped veneer part 102.1 Straight top edge of the first veneer part 102.2 Straight top edge of the second veneer part 200 Single strip-shaped veneer part 200.1 First V-shaped groove 200.2 Second V-shaped groove 210 Central longitudinal axis of the single strip-shaped veneer part B Width of the upper longitudinal edge of the frame HH Height of the frame L Length of the frame 1 Length of the cladding part h Height of the cladding part b Width of the back section of the cladding part.

Claims

1. Method for coating a metal drawer frame member (1) with veneer (2), comprising the following method steps: - providing an elongate, cross-sectionally U-shaped casing part (4) which has a rear portion (4.r), with a width (b) corresponding to the width (B) of the upper longitudinal edge (1.r) of the frame member (1), and has two side portions (4.1, 4.2), extending away from said rear portion substantially parallel to one another, composed of veneer, said side portions having a height (h) corresponding substantially to the height (H) of the frame member (1) and having a length (1) corresponding to the length (L) of the frame member (1), wherein the inner surfaces, facing towards one another, of the side portions (4.1i, 4.2i) have an adhesive portion (6.1, 6.2), extending at least over part of the height (h) of each side portion (4.1, 4.2) and having a thermally post-crosslinkable adhesive, and optionally have an adhesive-free transition portion (8.1, 8.2), arranged between the adhesive portion (6.1, 6.2) and the rear portion (4.r), - applying further adhesive (10), in particular liquid adhesive, an adhesive reactivatable by way of heat and / or a thermally post-crosslinkable adhesive, to the upper longitudinal edge (1.r) of the frame member (1) or to the inner side (4.ri) of the rear portion (4.r) of the casing part (4), characterized by the following further method steps, - spreading apart the free ends (4.1.a, 4.2.a) of the side portions (4.1, 4.2) of the casing part (4), - placing the spread-apart casing part (4) onto the upper longitudinal edge (1.r) of the frame member (1), - moving the free ends (4.1a, 4.2a) of the side portions (4.1, 4.2) of the casing part (4) towards one another in such a way that the adhesive portions (6.1, 6.2) on the inner surfaces (4.1i, 4.2i) of the first and second side portions (4.1, 4.2) bear against the outer surface (1.1, 1.2) of the frame member (1), and - curing the thermally post-crosslinkable adhesive (10) in the adhesive portions (6.1, 6.2) by preferably inductive heating of the frame member (1).

2. Method according to Claim 1, characterized by the following further method steps: - providing a first and second strip-shaped veneer part (100.1, 100.2), which in each case have a rectilinear top edge and bottom edge and also an inner surface which faces towards the outer surface (1.1, 1.2) of the frame member (1), - applying a first adhesive layer (10) of the thermally post-crosslinkable adhesive to the inner surface (100.1i, 100.2i) of the first veneer part (100.1) in such a way that the first adhesive portion (6.1) and optionally a first adhesive-free transition portion (8.1) arranged between the top edge (102.1) of the first veneer part (100.1) and the first adhesive portion (6.1) are formed, - applying a second adhesive layer (10) of the thermally post-crosslinkable adhesive to the inner surface (100.2i) of the second veneer part (100.2) in such a way that the second adhesive portion (6.2) and optionally a second adhesive-free transition portion (8.2) arranged between the top edge (102.2) of the second veneer part (100.2) and the second adhesive portion (6.2) are formed, - providing a strip-shaped rear element (12) with an outer longitudinal portion (12r) and with two parallel side surfaces (12.1 and 12.2) which are arranged at a right angle thereto, and - adhesively bonding the side portions (4.1, 4.2) of the first and second veneer parts (100.1, 100.2) in the region of the respective rectilinear top edges (102.1, 102.2) to the parallel side surfaces (12.1 and 12.2) of the strip-shaped rear element (12) to form a casing part (4).

3. Method according to Claim 2, characterized in that the side portions (4.1, 4.2), prior to being adhesively bonded to the strip-shaped rear element (12), are machined, in particular cut to the desired height and / or width and / or length and preferably provided with punching openings (14).

4. Method according to one of Claims 1 to 3, characterized in that the thermally post-crosslinkable adhesive is a hot-melt adhesive with a melting temperature of preferably 50°C or comprises one that is thermally post-crosslinkable above a crosslinking temperature of preferably 70°C.

5. Method according to Claim 4, characterized in that the further adhesive (10) applied to, preferably sprayed onto, the upper longitudinal edge (1.r) of the frame member (1) or applied to, preferably sprayed onto, the inner side (4.ri) of the rear portion (4.r) of the casing part (4) is a liquid adhesive which is post-crosslinkable by way of heat and which has substantially the same melting temperature and crosslinking temperature as the thermally post-crosslinkable hot-melt adhesive.

6. Method according to Claim 4 or 5, characterized in that the adhesive portions (6.1, 6.2) on the first and second side portions (4.1, 4.2) of the casing part (4) are formed by a layer of the thermally post-crosslinkable hot-melt adhesive, which layer is applied as a film web to the respective adhesive portions (6.1, 6.2) over the full area thereof and, by being briefly heated above the melting point to a temperature above the melting temperature and below the cross-linking temperature and then cooled, is bonded to the material of the respective first and second veneer parts (100.1, 100.2).

7. Method according to Claim 6, characterized in that the respective first and second veneer parts (100.1, 100.2) are bonded in the region of the respective rectilinear top edges (102.1, 102.2) to the parallel side surfaces (12.1 and 12.2) of the strip-shaped rear element (12) by positioning and pressing the two parallel veneer parts (100.1, 100.2) in the region of the rectilinear top edges against the parallel side surfaces (12.1 and 12.2) of the strip-shaped rear element (12) while the first and second veneer parts (100.1, 100.2) are simultaneously heated to a temperature above the crosslinking temperature, wherein the heat energy is supplied preferably exclusively in the region of the strip-shaped rear element (12), in particular in the region of the parallel side surfaces (12.1 and 12.2) of the strip-shaped rear element (12).

8. Method according to Claim 7, characterized in that the two parallel veneer parts (100.1, 100.2) are pressed against the parallel side surfaces (12.1 and 12.2) of the strip-shaped rear element (12) by two mutually oppositely situated heated pressure bars.

9. Method according to Claim 1, characterized by the following further method steps: providing a connected single strip-shaped veneer part (200) having a width that corresponds substantially to the sum of the heights of the first and second side portions (4.1, 4.2) plus the width of the rear portion (4.r), forming a first V-shaped groove (200.1) and a second V-shaped groove (200.2) with a spacing of half the width of the rear portion (4.r) on both sides of a central longitudinal axis (210) over the length of the single strip-shaped veneer part (200), applying the first and second adhesive layers of thermally post-crosslinkable adhesive to the top side of the single strip-shaped veneer part for the formation of the first and second adhesive portions (6.1, 6.2) and optionally of an adhesive-free transition portion (8.1, 8.2) arranged between the respective adhesive portions (6.1, 6.2) and the rear portion (4.r), introducing the adhesive (10) along the first and second V-shaped grooves (200.1, 200.2), and folding over through a right angle those portions of the single strip-shaped veneer part (200) which are arranged outside the rear portion (4.r), to form the cross-sectionally U-shaped casing part (4), and curing the adhesive (10) in the first and second V-shaped grooves (200.1, 200.2).

10. Method according to one of Claims 1 to 3, characterized in that the adhesive portions (6.1, 6.2) on the first and second side portions (4.1, 4.2) are formed by double-sided, thermally post-crosslinkable adhesive tape, in particular a PU adhesive film, whose top side, after the adhesive bonding, is preferably covered by a peel-off protective film, which is particularly preferably already removed prior to the thermally activatable liquid adhesive being sprayed onto the inner side of the strip-shaped rear element (12) or which, alternatively, is already removed prior to the two veneer parts (100.1, 100.2) being adhesively bonded to the strip-shaped rear element (12).

11. Method according to one of Claims 1 to 3, characterized in that the adhesive portions (6.1, 6.2) on the first and second side portions (4.1, 4.2) are formed by a liquid adhesive which is dryable under exposure to air and, in the dried state, is post-crosslinkable thermally by way of heat, preferably a post-crosslinking PU dispersion, which is applied to, in particular sprayed onto, the side portions (4.1, 4.2) and which, preferably, is dried by exposure to air prior to the casing part being placed onto the metal frame member.

12. Method according to one of the preceding claims, characterized in that the further adhesive is a liquid adhesive which is dryable under exposure to air and, in the dried state, is post-crosslinkable thermally by way of heat, preferably a post-crosslinking PU dispersion, which is sprayed onto the upper longitudinal edge (1.r) of the frame member (1) or onto the inner side (4.ri) of the rear portion (4.r) of the casing part (4), and in that the further adhesive is dried by exposure to air prior to the casing part (4) being placed onto the frame member (1).

13. Method according to one of the preceding claims, characterized in that the frame member (1), after the casing part (4) has been placed onto the upper longitudinal edge (1.r) of the frame member (1), is introduced into a vacuum chamber with flexible side walls, in particular into a closable silicone pocket, and this is closed off and subjected to a vacuum, and in that, subsequently, the closed-off, evacuated vacuum chamber, with the frame member (1) accommodated therein, is heated for a predefined period of time of preferably 10 minutes to a temperature above the crosslinking temperature, in particular in a furnace.

14. Casing part (4) for use in a method according to one of the preceding claims, having a rear portion (4.r), which has a width (b) corresponding to the width (B) of the upper longitudinal edge (1.r) of a frame member (1) to be coated, and having two side portions (4.1, 4.2), extending away from said rear portion substantially parallel to one another, composed of veneer, said side portions having a height (h) corresponding substantially to the height (H) of the frame member (1) and having a length (1) corresponding to the length (L) of the frame member (1), wherein the inner surfaces (4.1i and 4.2i), facing towards one another, of the side portions (4.1, 4.2) have an adhesive portion (6.1, 6.2), extending at least over part of the height of each side portion (4.1, 4.2) and having a thermally post-crosslinkable adhesive, and optionally have an adhesive-free transition portion (8.1, 8.2), arranged between the respective adhesive portion (6.1, 6.2) and the rear portion (4.r), wherein the thermally post-crosslinkable adhesive is a hot-melt adhesive with a melting temperature of preferably 50°C or comprises one that is thermally post-crosslinkable above a crosslinking temperature of preferably 70°C.

15. Use of a casing part (4) according to Claim 14 for coating a drawer frame member (1), in particular metal frame member, of a furniture cabinet, in particular a kitchen cabinet, living-room cabinet, bedroom cabinet or a chest of drawers, with veneer.

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