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 state of the art to use drawers in furniture, particularly kitchen and office furniture, that are not made of solid wood for cost reasons, but instead use steel side and rear frames connected to the front and back panels by screw or plug-in connections, forming the base of the drawer. These steel frame systems are often pre-assembled in automated assembly processes in the kitchen furniture industry and then inserted into the kitchen cabinets.

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

[0004] Therefore, wooden drawer systems are continually being developed that offer a certain degree of compatibility with certain steel drawer frames, making them easier to integrate into industrial kitchen furniture manufacturing processes than traditional solid wood drawers. However, the systems currently available on the market only meet this requirement to a limited extent, as the functionality of steel drawer frames can hardly be achieved with a wooden or wood-based material frame.

[0005] Accordingly, it is an object of the present invention to provide a method by which industrially manufactured steel-frame drawer systems can be redesigned with minimal effort while retaining their production-related advantages in such a way that their external appearance corresponds to that of a wooden drawer. This object is achieved according to the invention by a method having the features of claim 1.

[0006] A further object of the invention is to provide a casing part and its use with which the frames, in particular metal frames of a steel frame drawer system, can be adapted with little effort in terms of their visual appearance to the frames of a wooden drawer.

[0007] This object is achieved according to the invention by a sheathing part and a use thereof having the features of claims 14 and 15.

[0008] According to the invention, the method according to the invention comprises the following method steps: Providing an elongated, cross-sectionally U-shaped sheathing part with a back section having a width corresponding to the width of the upper longitudinal edge of the frame, and two side sections made of veneer extending substantially parallel to one another from the back section, which side sections have a height substantially corresponding to the height of the frame and a length corresponding to the length of the frame, wherein the mutually facing inner surfaces of the side sections have an adhesive section extending at least over part of the height of each side section and comprising a thermally post-crosslinkable 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-reactivatable and / or a thermally post-crosslinkable adhesive,onto the upper longitudinal edge of the frame or onto the inside of the back portion of the cladding part, spreading the free ends of the side portions of the cladding part, placing the spread cladding part onto the upper longitudinal edge of the frame, moving the free ends of the side portions of the cladding part towards each other such that the adhesive portions on the inner surfaces of the first and second side portions rest against the outer surface of the frame, and curing the thermally crosslinkable adhesive in the adhesive portions by heating the frame.

[0009] The drawers or drawers manufactured using the method according to the invention have the advantage that they have a visually 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 bland, single-colored steel frames.

[0010] A further advantage of the solution according to the invention is that the veneer-coated drawer systems can be assembled in the usual manner for steel frame drawer systems, cost-effectively and at high production speed using the equipment available in the industry.

[0011] The advantage of the method according to the invention lies in the manufacturing process itself, since the known steel frames cannot be covered with the classic veneering methods.

[0012] The side panels / frames are sheet steel constructions with integrated functional elements. This allows, for example, easy snap-on of the front panel, as well as height, side, and tilt adjustment, and simple assembly of the drawer after coating with the covering part.

[0013] According to the invention, suitable coating materials such as wood veneers or cover materials such as leather, linoleum and laminates with which the frame is to be coated are coated, preferably as bellows or rolled goods, with an adhesive substrate, for example with a double-sided adhesive film, the outer adhesive surface of which is covered in a known manner by a removable protective film after gluing. In a particularly preferred embodiment of the method, the wood veneers are coated over their entire surface with a thermally post-crosslinkable hot melt adhesive which, for example, has a melting temperature of preferably 50°C and which can be thermally post-crosslinked by heating to a crosslinking temperature of preferably 70°C. Such a hot melt adhesive in the form of a double-sided heat-activatable adhesive film is sold, for example, by Lohmann GmbH & Co.KG, D-56504 Neuwied under the product name "DuploTEC 12223 SBF LTC". The thermally post-crosslinkable hot melt adhesive can be heated, for example, to a temperature above the liquefaction temperature and below the crosslinking temperature. Then, in the liquefied state (and not yet fully crosslinked), it can be applied over the entire surface of the strip-shaped veneer material or veneer parts, e.g., using conventional application rollers. After cooling, a non-adhesive (dry) veneer part is created, which can be wound up again into a coil if desired. The non-adhesive veneer part can then also be further processed very easily and with little effort in conventional processing stations for veneer parts, for example, by punching and cutting to create the precisely cut pieces required for the production of the coated frame with the individually introduced cutouts.

[0014] Alternatively, the previously described hot melt adhesive can be applied as a dry film layer of a desired thickness to the preferably strip-shaped veneer material or, alternatively, to the pre-cut veneer pieces. It can be melted by heating to a temperature above the melting temperature and below the crosslinking temperature, and then cooled again to bond the veneer piece with the thermally post-crosslinkable adhesive, or in particular, to coat it over its entire surface with it. For this purpose, the hot melt adhesive has the property that the melting temperature and the crosslinking temperature are at least approximately 5°C apart, but preferably at least approximately 10°C apart, and particularly preferably approximately 20°C apart.

[0015] Alternatively, the adhesive film in the bonding sections can comprise a heat-curing PU film containing a thermally post-crosslinkable adhesive in film form with a thickness of, for example, 0.05 mm. It is preferably wound on a roll with a release paper, similar to double-sided adhesive tape. Such a heat-curing PU film is marketed, for example, under the brand name "DuploTec 12223 SBF LTC" by Lohmann GmbH & Co. KG in Neuwied, Germany.

[0016] This PU film is first laminated to the veneer at a relatively low temperature of, for example, 50°C, similar to double-sided adhesive tape. The covering part is then glued in the manner described in more detail below and, after spreading the side parts, is applied to the metal frame. After application, the metal frame is heated in an oven or, alternatively, inductively for approximately 1 minute, preferably to approximately 90°C, while the covering part is pressed against it. This heating heats the thermally crosslinkable adhesive of the hot-melt adhesive film above the crosslinking temperature, initiating the crosslinking reaction. As the applicant has discovered, the strength and long-term durability achievable in this way are significantly higher than with conventional double-sided adhesive tapes, whose acrylate adhesive films are known to exhibit a "cold flow" that can lead to the loosening of the adhesive joints during extreme and prolonged climatic fluctuations.

[0017] As an alternative to the use of the heat-crosslinking PU adhesive film, a liquid adhesive, preferably in the form of a thermally post-crosslinkable PU dispersion or a similar wet adhesive, can also be used.

[0018] The liquid adhesive is preferably sprayed onto the inside of the finished encasing part via nozzles, or alternatively, rolled onto rollers and dried by exposure to air for e.g., 30 minutes. The encasing part, with the dried adhesive layer, is then applied to the metal frame within approximately 4 hours. The dried liquid adhesive is then activated, similar to the thermosetting film, by heating the frame with the attached encasing part, preferably in an oven or alternatively by inductively heating the metal frame to a temperature that triggers the crosslinking reaction and thus the complete post-crosslinking of the adhesive. For example, in the case of the aforementioned PU dispersion adhesive with the brand name "JOWAPUR," distributed by JOWAT in Detmold, Germany, this temperature is approximately 80°C.By using a liquid PU dispersion adhesive that dries upon exposure to air and then crosslinks thermally upon heating to a crosslinking temperature of, for example, 80 °C, the provision of adhesive-free areas, as required when coating with a conventional liquid adhesive, can be eliminated, since the sheathing part is completely coated on the inside when the liquid adhesive is sprayed. This advantageously simplifies the manufacturing process.

[0019] Veneers, especially wood veneers, are preferably used as the coating material. These veneers already have a largely finished surface and are supplied in rolls. For veneers, the use of fleece-backed, sanded, primed, and / or varnished veneers is preferred.

[0020] In a next step, precisely fitting cuts for the coating are created from the raw material, e.g. by punching, milling, sawing as well as laser or water jet cutting, which have the outer dimensions of the respective outer surface of the frame to be covered, and into which the required openings are also made, which, after the frame has been covered, provide access to the recesses formed in it, in particular for screw connections.

[0021] The prefabricated individual parts are then assembled to form a complete, precisely fitting sheathing part, which is preferably done by gluing a thin wooden strip to the upper edge to increase stability and allow for sanding.

[0022] In one embodiment of the invention, the encasing part is produced by applying a layer of the thermally post-crosslinkable adhesive to the first and second strip-shaped veneer parts, each of which, after trimming, has a straight upper edge and lower edge as well as an inner surface facing the outer surface of the frame, in the manner described above, so that the respective adhesive section and, optionally, an adhesive-free transition section arranged between the upper edge of the respective veneer part and the first adhesive section are created. The side sections of the first and second veneer parts thus produced are subsequently glued to the parallel side surfaces of a provided strip-shaped backing element in the region of their respective straight upper edges to form the encasing part.

[0023] In the preferred embodiment of the invention, in which the two veneer parts are coated over their entire surface with the thermally post-crosslinkable hot melt adhesive applied in the manner described above, the respective first and second veneer parts are connected in the region of the respective straight upper edges to the parallel side surfaces of the strip-shaped back element by placing the two veneer parts running parallel to one another and pressing them in the region of the straight upper edges against the parallel side surfaces of the strip-shaped back element while simultaneously heating the first and second veneer parts to a temperature above the crosslinking temperature.In this case, 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-crosslinkable hot melt adhesive cures exclusively in this area and connects the two veneer parts with the strip-shaped back element to form the sheathing part.

[0024] Preferably, the two veneer parts running parallel to each other 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 pressure, for example, by pneumatic cylinders.

[0025] The two veneer parts of the sheathing part produced in this way have opposing inner surfaces coated with the post-crosslinkable hot melt adhesive, in which the hot melt adhesive is no longer liquid but is advantageously not yet fully crosslinked.

[0026] Optionally, it is possible to form the sheathing part by introducing V-shaped grooves along the upper two longitudinal edges of the sheathing part on the side which, in the finished sheathing part, forms the inner surfaces adjacent to the outside of the frame, and folding the two side sections of the blank, which form the legs of the sheathing part with a U-shaped cross-section, in an orthogonal direction to the plane of the blank.

[0027] By using approximately 1-3 mm thick wooden strips, which can be glued to the veneer, particularly between the two V-shaped grooves, or veneers that are glued multiple times along the top edge, i.e., the spine of the sheathing, you can advantageously create highly resilient longitudinal edges, similar to solid wood edge banding on tabletops. It is advantageous to apply adhesive to the V-shaped grooves before or after folding the side sections. After curing, this adhesive ensures that the side sections retain their orthogonal position relative to the spine.

[0028] The sheathing part can then be finished, e.g., by milling and grinding, which is preferably done primarily on the upper edge. The outer visible surfaces of the sheathing part are preferably pre-finished to a largely finished surface, so that they require no further finishing.

[0029] Furthermore, it can optionally be provided that the surface of the sheathing part is refined in a further step, depending on the raw material, e.g. by painting.

[0030] The finished casing is then applied to the drawer frame. To do this, the protective film, if present, is removed, and the sides are opened using, for example, vacuum suction cups that grip the side sections and spread them apart in a V-shape.

[0031] In the preferred embodiment of the invention, an additional adhesive, in particular a liquid adhesive, is applied to the upper edge of the frame before the covering part is placed on the frame, since an adhesive film in this area would complicate application. This additional adhesive is particularly preferably also a heat-crosslinkable liquid adhesive, which preferably has essentially the same melting temperature and crosslinking temperature as the thermally crosslinkable hot melt adhesive, which is applied to the inner surfaces of the first and second veneer parts as a web-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.

[0032] Alternatively, it is possible to arrange the sheathing part with the back facing down, spread it open using the vacuum suction cups, apply the additional adhesive from above to the inner surface of the back section, and then insert the frame into the sheathing part from above.

[0033] Instead of a double-sided adhesive film, a reactivatable adhesive can also be applied, e.g. a hot melt adhesive, which is either applied hot or reactivated with heat after the sheathing part has been placed on the frame, or is thermally crosslinked in the manner described above.

[0034] Alternatively, traditional wet gluing is also conceivable. Unlike the use of an adhesive film or a thermally post-curable or reactivatable adhesive and another adhesive, this method requires the application of a necessary pressure, which requires a correspondingly stable frame.

[0035] The invention is described below with reference to the drawings using preferred embodiments of the invention.

[0036] The drawings show: Fig. 1 is a schematic representation of two strip-shaped veneer parts, each with a side section formed by punching, to which double-sided adhesive tape is applied to provide the first and second adhesive sections, Fig. 2 is a schematic spatial representation of a sheathing part according to the invention before gluing the side sections to the back section, Fig. 3 is a schematic spatial representation of the finished glued sheathing part of Fig. 2 during sanding, Fig. 4 a schematic spatial representation of a fully bonded covering part during spraying of a coloring or impregnating coating material, Fig. 5 a front view of the covering part spread open by suction cups before being placed on a drawer frame to be coated or covered, Fig. 6 a spatial representation of a fully coated drawer frame, and Fig. 7 a spatial representation of a further embodiment of the invention, in which the covering part is formed from a coherent 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.

[0037] As in the Figuren 1 bis 7 shown, is used to coat a Fig. 5 and 6shown drawer frame 1, which is preferably a metal frame, with veneer 2, first an elongated, cross-sectionally U-shaped casing part 4 is provided, which, for example, in the final form in Fig. 4 This 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 from this essentially parallel to one another at right angles. The side sections 4.1, 4.2 each have a height h corresponding essentially 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.

[0038] As in the Figs. 2 , 4 and 5As can be seen, the mutually 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 part 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 comprise 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 is shown.

[0039] In order to fix the covering part 4 to the frame 1 to be coated, adhesive 10, in particular liquid adhesive, a heat-reactivatable or thermally crosslinkable 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 covering part 4, as shown in the sectional view of Fig. 5 is indicated.

[0040] 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 out 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 is indicated.

[0041] Finally, the spread free ends 4.1a, 4.2a of the side sections 4.1, 4.2, which are preferably held in the spread apart position by means of suction devices 20 which are only schematically indicated, are Fig. 5 are held, 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 sections 4.1, 4.2 rest on the respective outer surface 1.1, 1.2 of the frame 1 and are glued to it.

[0042] In order to achieve particularly good contact of the inner surfaces 4.1i, 4.2i also in the area of ​​the longitudinal edges of the frame 1, the frame 1 can, after the sheathing part 4 has been placed on the upper longitudinal edge 1.r of the frame 1, be placed into a vacuum chamber (not shown in detail) with flexible side walls, in particular into a sealable silicone bag. This bag is then closed and subjected to a vacuum so that all areas of the sheathing part 4 bear against the outside of the frame 1 with uniform contact pressure. Following this, the closed, evacuated vacuum chamber with the frame 1 accommodated therein is heated for a predetermined period of time, e.g., approximately 10 minutes, to a temperature which is above the crosslinking temperature of the thermally post-crosslinkable adhesive.The heating is preferably carried out in a known oven and / or by irradiation with an IR heat source and / or by inductive heating of the metal frame.

[0043] After the curing of the thermally post-crosslinkable adhesive, or the further liquid adhesive 10 by heating the metal frame 1 with the sheathing part 4 placed thereon above the crosslinking temperature of e.g. 70 - 80° for a period of preferably 10 minutes, which thereby polymerically crosslinks in the adhesive sections 6.1 and 6.2, a Fig. 6 shown frame 1 covered with veneer 2, the metal core of which can be connected 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, with the standardized front panels and rear walls of the respective systems (not shown in detail) to form a drawer, which gives the viewer the impression of a hand-made wooden drawer.

[0044] In a first embodiment of the method according to the invention, as shown in Fig. 1 shown, a first and a second strip-shaped veneer part 100.1, 100.2 are 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 adhesive layer 10 is then applied to this inner surface 100.1i, 100.2i of the respective strip-shaped veneer part 100.1, 100.2 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 created.The optional first and second adhesive-free transition sections are preferably only provided when using self-adhesive tape or adhesive in order to enable exact positioning of the sheathing part 4 relative to the frame 1 after the sheathing part 4 has been placed on.

[0045] Furthermore, a 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 a right angle to this. In the case of the optional transition sections provided, this is glued to the respective transition section 8.1, 8.2 of the first and second veneer parts 100.1, 100.2 in the region 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 sheathing part 4, as shown in Fig. 2 is indicated.

[0046] In the case of the preferably used thermally post-crosslinkable hot melt adhesive, which is applied, for example, as described above by briefly melting and cooling a corresponding film of hot melt adhesive over the entire surface of the veneer material, the bonding of the two parallel side surfaces 12.1 and 12.2 to the strip-shaped back element 12 is carried out in a particularly advantageous manner in that the respective first and second veneer part 100.1, 100.2 is pressed against the parallel side surfaces 12.1 and 12.2 of the strip-shaped back element 12 in the area of ​​the respective straight upper edges 102.1, 102.2 by two opposing heated pressure strips.

[0047] As discovered by the applicant in this context, the thermally post-crosslinkable hot melt adhesive can be completely post-crosslinked exclusively in this narrow region of the side surfaces 12.1 and 12.2 by the thermal energy introduced by the heated pressure strips (not shown in detail in the drawings) through the veneer material into the layer of hot melt adhesive, without visually impairing the structure and surface of the veneer material on the outside of the sheathing part 4. In the remaining area of ​​the adhesive sections 6.1, 6.2, however, no final crosslinking of the hot melt adhesive takes place, so that the fully bonded sheathing part 4 with the adhesive sections 6.1, 6.2 arranged on the inner sides of the veneer material and which are not sticky at room temperature, can be expanded in the manner described above and, with the addition of the further adhesive, can be guided as a component over the frame 1 in order to bond the veneer parts 100.1, 100.2 is then to be inseparably bonded to the frame 1 by heating it above the cross-linking temperature.

[0048] After gluing, the side sections 4.1, 4.2 of the casing part 4, which is U-shaped in cross section, 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 fastening the frame 1 to the front and rear walls of the drawers can then be actuated.

[0049] According to a further embodiment of the invention, it may alternatively be provided to 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.

[0050] A first, preferably V-shaped groove 200.1 and a second, preferably V-shaped groove 200.2 are then introduced into the connected individual 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 individual strip-shaped veneer part 200, as shown in Fig. 7 is indicated.

[0051] Before or after the introduction of the two grooves 200.1 and 200.2, a first and second adhesive layer is applied to the upper side of the individual strip-shaped veneer part 200, ie to the side of the veneer part on which the grooves 200.1, 200.2 are introduced, at a distance from the first and second V-shaped grooves 200.1, 200.2, which form the first and second adhesive sections 6.1, 6.2 and optionally define the adhesive-free transition section 8.1, 8.2 which is optionally arranged between the adhesive sections 6.1, 6.2 and the back section 4.r.

[0052] In a preferred embodiment of the invention, adhesive, in particular liquid adhesive 10, can next be introduced into 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 is then folded at a right angle to the sheathing part 4 which is U-shaped in cross section, as shown in the Fig. 7 is indicated by the dashed arrows. After the adhesive 10 has hardened, the sheathing part 4, which is stable in its shape, can be Fig. 3 indicated on its outside sanded and / or desired case, as in Fig. 4 shown, painted.

[0053] As the applicant has found, it is particularly advantageous with regard to simple and cost-effective production and handling of the prepared sheathing parts 4 if the provision of the sheathing part 4, which is U-shaped in cross section and has 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 made of veneer 2, each provided on its inner side 4.1i, 4.2i with a respective first and second adhesive layer 10.1, 10.2, is carried out by unrolling and processing strip-shaped veneer 2 rolled into a coil. Furthermore, according to a further concept underlying the invention, the adhesive sections 6.1, 6.2 on the first and second side sections 4.1, 4.2 can be formed, as already explained above, by a thermally post-crosslinkable double-sided adhesive tape, the upper side of which is preferably covered by a removable protective film after bonding.The double-sided adhesive tape can be provided as a roll and continuously adhered to the upper side of the strip-shaped veneer parts 200 during the longitudinal cutting, cutting to length, and punching of the respective blanks. For this purpose, if a thermally post-crosslinkable PU adhesive film is preferably used, it can be provided that the veneer of the sheathing part 4 is previously heated to a temperature of, for example, 50°C, which is below the crosslinking 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, it is possible to remove the protective film 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 the free ends 4.1a, 4.2a of the side sections 4.1, 4.2 and before placing the spread-out covering part 4 onto the upper longitudinal edge 1.r of the frame 1 (. Fig. 5 ) to remove.

[0054] 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 enables the finished sheathing part 4, after removing the protective film from the double-sided adhesive tape, with the spread-out side sections 4.1 and 4.2, to be precisely positioned in the desired position above the frame 1 by pushing it back and forth, whereby, with sufficiently precisely manufactured frames 1 and sheathing cables 4, post-processing of the coated frame 1 ( Fig. 6 ) can be omitted.

[0055] According to the presentation by Fig. 5The spreading of the free ends 4.1a, 4.2a of the side sections 4.1, 4.2 of the casing part 4 can be carried out by motor-operated suction devices 20, which suck the side sections 4.1 and 4.2 and are then moved outwards away from the frame 1 in the direction of the arrows (not shown), for example by an associated pneumatic cylinder or an electrically operated actuator (not shown).

[0056] The invention further relates to the use of a previously described sheathing part 4 for use in a method according to the invention described at the outset, wherein the sheathing 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 one another therefrom, which have a height h substantially corresponding to the height H of the frame 1 and a length l 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 part of the height of each side section 4.1, 4.2 and optionally an adhesive-free transition section 8.1 arranged between the respective adhesive section 6.1, 6.2 and the back section 4.r, 8.2.

[0057] The covering part 4 is preferably used for coating or cladding a drawer frame, in particular a metal frame, for a piece of cabinet furniture, in particular a kitchen cabinet, living room cabinet, bedroom cabinet or chest of drawers, with veneer.

[0058] List of reference symbols 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 Covering 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 the inner surface of the first side section, 6.2 Second adhesive section on the 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 12.2Second side surface (adhesive surface) of the spine section 14Punching opening 20Suction devices for opening the wrapping parts 100.1First strip-shaped veneer part 100.1iInner surface of the first strip-shaped veneer part 100.2Second strip-shaped veneer part 100.2iInner surface of the second strip-shaped veneer part 102.1Straight upper edge of the first veneer part 102.2Straight upper edge of the second veneer part 200Single strip-shaped veneer part 200.1First V-shaped groove 200.2Second V-shaped groove 210Central longitudinal axis of the single strip-shaped veneer part BWidth of the upper longitudinal edge of the frame HHeight of the frame LLength of the frame 1Length of the sheathing part hHeight of the sheathing part bWidth of the back section of the sheathing part.

Claims

1. A method for coating a metal drawer frame (1) with veneer (2), comprising the following method steps: - providing an elongated, cross-sectionally U-shaped covering part (4) with 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 which extend away from the back section essentially parallel to one another and which have a height (h) essentially corresponding to the height (H) of the frame (1) and a length (l) corresponding to the length (L) of the frame (1), wherein the mutually facing inner surfaces of the side sections (4.1i, 4.2i) have an adhesive section (6.1, 6.2) extending at least over part of the height (h) of each side section (4.1, 4.2) with a thermally crosslinkable adhesive and optionally one between the adhesive section (6.1, 6.2) and the back section (4.r) arranged adhesive-free transition section (8.1, 8.2), - applying further adhesive (10), in particular liquid adhesive, a heat-reactivatable and / or thermally post-crosslinkable adhesive, 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 casing part (4), - spreading the free ends (4.1.a, 4.2.a) of the side sections (4.1, 4.2) of the casing part (4), - placing the spread casing part (4) on the upper longitudinal edge (1.r) of the frame (1), - moving the free ends (4.1a, 4.2a) of the side sections (4.1, 4.2) of the casing part (4) towards each other in such a way 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) bear against the outer surface (1.1, 1.2) of the frame (1), and - curing of the thermally crosslinkable adhesive (10) in the adhesive sections (6.1, 6.2) by preferably inductive heating of the frame (1).

2. Method according to claim 1, characterized bythe following further method steps: - Providing a first and second strip-shaped veneer part (100.1, 100.2), each having a straight upper edge and lower edge as well as an inner surface facing the outer surface (1.1, 1.2) of the frame (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) such that the first adhesive section (6.1) and optionally a 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) 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), such that the second adhesive section (6.2) and optionally a gap between the upper edge (102.2) of the second veneer part (100.2) and the second adhesive section (6.2) arranged second adhesive-free transition section (8.2), - providing a strip-shaped back element (12) with an outer longitudinal section (12r) and two parallel side surfaces (12.1 and 12.2 arranged at a right angle thereto, and - gluing the side sections (4.1, 4.2) of the first and second veneer part (100.1, 100.2) in the region of the respective straight upper edges (102.1, 102.2) to the parallel side surfaces (12.1 and 12.2) of the strip-shaped back element (12) to form a sheathing part (4).

3. Method according to claim 2, characterized in that the side sections (4.1, 4.2) are processed before being glued 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).

4. Method according to one of claims 1 to 3, characterized in thatthe thermally post-crosslinkable adhesive is a hot melt adhesive with a melting temperature of preferably 50°C or contains 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, preferably sprayed, 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 casing part (4) is a heat-crosslinkable liquid adhesive which has essentially the same melting temperature and crosslinking temperature as the thermally crosslinkable hot melt adhesive.

6. Method according to claim 4 or 5, characterized in thatthe adhesive sections (6.1, 6.2) on the first and second side sections (4.1, 4.2) of the sheathing part (4) are formed by a layer of the thermally post-crosslinkable hot melt adhesive, which is applied as a film web over the entire surface of the respective adhesive section (6.1, 6.2) and is connected to the material of the respective first and second veneer part (100.1, 100.2) by briefly heating it above the melting point to a temperature above the melting temperature and below the crosslinking temperature and then cooling it.

7. Method according to claim 6, characterized in thatthe respective first and second veneer parts (100.1, 100.2) are joined in the region of the respective straight upper edges (102.1, 102.2) to the parallel side surfaces (12.1 and 12.2) of the strip-shaped back element (12) by placing the two veneer parts (100.1, 100.2) running parallel to one another and pressing them in the region of the straight upper edges against the parallel side surfaces (12.1 and 12.2) of the strip-shaped back element (12) while simultaneously heating the first and second veneer parts (100.1, 100.2) to a temperature above the cross-linking temperature, wherein the heat energy is preferably supplied exclusively in the region of the strip-shaped back element (12), in particular in the region of the parallel side surfaces (12.1 and 12.2) of the strip-shaped back element (12).

8. Method according to claim 7, characterized in thatthe two veneer parts (100.1, 100.2) running parallel to each other are pressed against the parallel side surfaces (12.1 and 12.2) of the strip-shaped back element (12) by two opposing heated pressure strips.

9. Method according to claim 1, characterized bythe following further method steps: providing a coherent individual strip-shaped veneer part (200) which has a width which essentially corresponds to the sum of the heights of the first and second side sections (4.1, 4.2) plus the width of the back section (4.r), introducing a first V-shaped groove (200.1) and a second V-shaped groove (200.2) 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 individual strip-shaped veneer part (200), applying the first and second adhesive layers made of thermally post-crosslinkable adhesive to the upper side of the individual strip-shaped veneer part to form the first and second adhesive sections (6.1, 6.2) and optionally an adhesive-free transition section (8.1, 8.2) arranged between the adhesive sections (6.1, 6.2) and the back section (4.r).2), introducing the adhesive (10) along the first and second V-shaped grooves (200.1, 200.2), and folding the sections of the individual strip-shaped veneer part (200) arranged outside the back section (4.r) at a right angle to the sheathing part (4) which is U-shaped in cross section 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 thatthe adhesive sections (6.1, 6.2) on the first and second side sections (4.1, 4.2) are formed by double-sided, thermally post-crosslinkable adhesive tape, in particular a PU adhesive film, the upper side of which is preferably covered by a removable protective film after bonding, which is particularly preferably removed before the thermally activatable liquid adhesive is sprayed onto the inside of the strip-shaped back element (12) or which, alternatively, is removed before the two veneer parts (100.1, 100.2) are bonded to the strip-shaped back element (12).

11. Method according to one of claims 1 to 3, characterized in thatthe adhesive sections (6.1, 6.2) on the first and second side sections (4.1, 4.2) are formed by a liquid adhesive which can be dried under the action of air and, in the dried state, can be thermally post-crosslinked by heat, preferably a post-crosslinking PU dispersion, which is applied, in particular sprayed, to the side sections (4.1, 4.2) and which is preferably dried by the action of air before the casing part is placed on the metal frame.

12. Method according to one of the preceding claims, characterized in thatthe further adhesive is a liquid adhesive which can be dried under the influence of air and, in the dried state, can be thermally post-crosslinked by heat, preferably a post-crosslinking PU dispersion, which is sprayed onto the upper longitudinal edge (1.r) of the frame (1) or onto the inside (4.ri) of the back section (4.r) of the sheathing part (4), and that the further adhesive is dried by the influence of air before the sheathing part (4) is placed on the frame (1).

13. Method according to one of the preceding claims, characterized in thatthe frame (1) is introduced into a vacuum chamber with flexible side walls, in particular into a sealable silicone bag, after the casing part (4) has been placed on the upper longitudinal edge (1.r) of the frame (1), this bag is sealed and subjected to a vacuum, and that subsequently the sealed, evacuated vacuum chamber with the frame (1) accommodated therein is heated for a predetermined period of time, preferably 10 minutes, to a temperature which is above the crosslinking temperature, in particular in an oven.

14. A casing part (4) for use in a method according to one of the preceding claims, comprising 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 which extend away from said back section essentially parallel to one another and which have a height (h) which essentially corresponds to the height (H) of the frame (1) and a length (l) which corresponds 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 at least part of the height of each side section (4.1, 4.2) with a thermally post-crosslinkable adhesive and optionally a adhesive layer (6.1, 6.2) between the respective adhesive section (6.1, 6.2) and the back section (4.r) arranged adhesive-free transition section (8.1, 8.2).

15. Use of a covering part (4) according to claim 14 for coating a drawer frame (1), in particular a metal frame, of a cupboard, in particular a kitchen cupboard, living room cupboard, bedroom cupboard or chest of drawers, with veneer.

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