Device for applying an edge band and method for processing such a device

Abstract

The device (3) for applying an edge band (2) to the narrow sides (11) of panel-shaped workpieces (1) is made of wood or wood substitute. The device (3) comprises an edge band feed device that transports an edge band (2) along a feed path (12) in the direction of a workpiece (1) to a joining area (F) in which the edge band (2) is joined to the workpiece (1). The device (3) further comprises a shaping device (5) that has a shaping element (5a), in particular a shaping rod, and is designed to impart to the edge band (2) a shape that deviates from the flat shape, in particular a curved shape, when viewed in cross-section relative to its longitudinal direction. The shaping device (5) is connected to a compressed air supply (8) that provides hot compressed air. The shaping device (5) comprises at least one compressed air line that guides the supplied hot compressed air into the shaping element (5a).The shaping element (5a) has air outlet openings through which the hot compressed air fed into the shaping element (5a) can exit the shaping element (5a).

Description

[0001] The invention relates to a device for applying an edge band according to the preamble of claim 1 and a method for processing an edge band.

[0002] Edgebands are generally applied to the narrow sides of panels made of wood or wood substitutes using appropriate equipment. To do this, an edgeband is taken from a roll and moved against the narrow side of a workpiece, where it is joined.

[0003] Edgebands are generally flat, flat structures that are joined to a flat, flat narrow side of a workpiece. However, the surfaces of narrow sides can also have other shapes. For example, as in the cross-sections of the Figures 1 and 2shown, the narrow sides 11 also have convex or, as here, concave shapes. The front of the narrow side is designated L2, the bottom of the concave recess is indicated by the line L1. If such a workpiece 1 is to be provided with an edge band, the edge band must be brought parallel to the direction X to the workpiece 1. Since the edge band basically has a flat shape in its initial state, it must be reshaped so that it can be fitted into the contour 11 in a form-fitting manner, as shown in Figure 2 As indicated, the edge band 2 is connected to the workpiece 1 in the area 11.

[0004] For this purpose, forming rods are generally used. These are parts of the devices for applying edgebands, with the help of which an edgeband is formed in its cross-section to its longitudinal extent. For this purpose, the edgeband is usually heated and brought into contact with the forming rod, resulting in a contour, for example, as can be seen in Figure 2 can recognize.

[0005] Figure 3shows a basic structure of a corresponding device 3. Here, a chain conveyor 4 can be seen, on which a workpiece 1 is transported in the direction of arrow P (direction X). An edge band 2 is then moved towards the workpiece 1 and formed accordingly in the area D by means of a forming device 5. The edge band thus formed is then joined to the narrow side of the workpiece 1 in the area L1, L2. Typically, the edge band is made adherent by activating or applying adhesive and is then pressed against the workpiece 1 via a pressure roller 6 and / or pressure shoes 7.

[0006] With this procedure, relative movements naturally occur because the edge band 2 has to be fed into the process via a feeding device, i.e. it moves in the same way as the workpiece 1. However, if the moving edge band 2 is guided past a forming rod or a forming device 5, contact will inevitably occur between the forming device 5 and the decorative side or the visible side of the edge band 2, which is on the outside in the finished workpiece 1, during the forming of the edge band 2. Contact with relative movements creates pressure or grinding marks on this side of the edge band 2, which overall reduce the quality of the decorative side.

[0007] The object of the present invention is therefore to provide a device of the type mentioned above and a method with which formed edge bands, particularly on their decorative side, can be joined to the narrow side of the workpiece 1 largely without sanding marks or the like. This object is achieved by a device for applying an edge band having the features of claim 1 and a method having the features of claim 6. Advantageous embodiments can be found in the dependent claims.

[0008] According to the invention, a device for applying an edge band to the narrow sides of panel-shaped workpieces made of wood or wood substitute is provided. The device comprises an edge band feed device that transports an edge band along a feed path toward a workpiece to a joining area where the edge band is joined to the workpiece. The feed path can extend over the entire area from an edge supply to a joining area where the edge band is then pressed against the narrow side of the workpiece. Furthermore, the device according to the invention comprises a shaping device that has a shaping element, in particular a shaping rod, and is designed to impart to the edge band a shape that deviates from the flat shape, in particular a curved shape, when viewed in cross-section relative to its longitudinal direction.This makes it possible to form so-called soft-forming edges on workpieces where the shape of the narrow side is no longer flat, but has, for example, concave or convex sections. According to the invention, the forming device is connected to a compressed air supply. This compressed air supply provides hot compressed air. Hot compressed air is understood to be compressed air at a temperature that is suitable for making the corresponding material of the edge band used in each case formable, for example elastically or possibly also plastically deformable. The temperature should preferably be only high enough that the melting point of the edge band material used, usually a plastic, is not yet reached. The forming device further comprises at least one compressed air line that guides the supplied hot compressed air into the forming element.The forming element itself has air outlet openings through which the hot compressed air fed into the forming element can escape from the forming element.

[0009] The invention has a whole series of advantages. Due to the inventive measure, according to which the shaping element is provided with air outlet openings, not only is the shaping element itself heated by the incoming hot compressed air, but an air cushion is also formed around the outside of the shaping element as the hot compressed air escapes. If an otherwise flat edge band is then guided past the shaping device, the air cushion created by the hot compressed air ensures that there is little or no contact between the edge band on its decorative side and the shaping element itself. Instead, the edge band is essentially heated by the hot compressed air flowing against it, making it deformable. Heating by the shaping device according to the invention is particularly effective due to the escaping hot compressed air and is particularly suitable for edge bands of greater thickness.It has been shown that, with the solution according to the invention, edgebands made of plastic, such as polypropylene or ABS, with thicknesses of up to 1 mm can be easily formed and attached to the corresponding workpiece. A further advantage of the more effective heating of the edgeband is that a hot-melt adhesive already applied and heated to the joining side, or a joining side of the edgeband that has been melted, for example, by laser radiation or hot air, is kept warm for longer due to the heat conduction effect through the edgeband.

[0010] Here, the compressed air cushion ensures minimal contact between the forming element on the one hand and the edge band on the decorative side on the other. This ensures that the decorative side itself is not damaged during the forming process; in particular, no pressure or grinding marks are created on the decorative side during transport through the device according to the invention.

[0011] According to a preferred embodiment of the present invention, the forming device is positioned along the feed line such that an edge band transported along the feed line enters the effective area of ​​the forming device. The effective area of ​​the forming device is considered to be the area in which the hot compressed air ensures that the edge band guided past the forming device becomes deformable. The effective area of ​​the forming device can extend to or just before the joining area. A pressure element in the form of a pressure roller or pressure shoe is then typically provided in the joining area.

[0012] The shaping element preferably has an outer contour that corresponds to a negative form of a contour to be imparted to the edge band. The hot compressed air then exiting through the openings is distributed accordingly around the outer contour of the shaping element such that the air cushion receives a corresponding or congruent outer contour, along which the edge band can then be formed according to the specifications. For this purpose, according to a further advantageous embodiment of the present invention, it can be provided in particular that the air outlet openings are present at least on the side of the shaping element facing the feed line. Of course, air outlet openings can also be present elsewhere; however, it is important that the air cushion created by the hot compressed air forms between the shaping element and the edge band.

[0013] In principle, the process for processing an edge band in the device according to the invention is as follows: a. an edge band is provided; this can be an edge band unwound from a roll or an edge strip that has already been cut to length; b. the edge band is transported along the feed line towards the workpiece or joining area; c. the edge band is heated and formed along the feed line using the forming device described above by introducing hot compressed air. This is preferably done by transporting the edge band in the area of ​​the feed line through the effective area of ​​the forming device and heating it with hot compressed air escaping from the openings in the forming element and bringing it towards the - preferably concave - profiled narrow side of the workpiece to be edged; d. the edge band heated in this way by the hot air is then joined to the narrow side of the workpiece, for example by a pressure roller and / or a pressure shoe pressing the edge band against the narrow side.

[0014] The edge band is attached to the workpiece, for example, by making the edge band adhere to the joining side either by melting it or by applying an adhesive.

[0015] The invention is described below with reference to Figures 1 to 7 explained in more detail. Figure 1 shows a workpiece according to the invention as a sectional view with a profiled narrow side before the application of an edge band. Figure 2 shows the view from Figure 1 after applying an edge band. Figure 3 shows a basic schematic structure of a device according to the invention as a plan view. Figure 4 shows the enlarged detail of detail D from Figure 3 . Figure 5 shows a section through the Figure 4 shown area along section line AA. Figure 6 shows a section through the Figure 4 shown area along the section line BB. Figure 7shows a section through the Figure 4 shown area along the section line CC.

[0016] The Fig. 1 and 2 have already been explained in the introduction to the description. The same applies to the basic structure according to Fig. 3 , so that in order to avoid repetition, reference is made to the above explanations. Basically, Z refers to the vertical direction perpendicular to the ground or to the Fig. 3 shown drawing plane, X is the transport direction in which the workpieces 1 are transported by the device 3 according to the invention, Y denotes the transverse direction transverse to X and perpendicular to Z. The incoming workpiece 1 (cf. Fig. 3 ) is transported in the direction of arrow P by a chain conveyor 4 through the device 3 according to the invention. The edge band 2 is fed to the workpiece 1 via a feeding device not shown here. The workpiece 1 has (as in Fig. 1(see) a narrow side 11 which is profiled. In the example shown, a concave profile is present between the lines L1 and L2. As can be seen in Fig. 3 recognizes, the forming device 5 is arranged on the side facing the edge band 2 with a slightly oblique course to the direction X or P in such a way that at least with its section 5b located further towards the joining area F in the direction of arrow P, it extends at least partially into this profiling between the lines L1 and L2.

[0017] The latter is particularly important in Fig. 4 The forming device 5 has a flank tapering at an angle to the direction X toward the joining area F, so that the incoming edge band 2, which is being formed or deformed on the forming device 5, is simultaneously guided into the profiling between L1 and L2. In the joining area, the previously bonded edge band 2 is then pressed against the workpiece 1.

[0018] As in Fig. 5 As shown, the edge band 2, which is initially flat in the section shown here, lies between the workpiece 1 and the forming device 5, which in turn has a forming element 5a, e.g. a forming rod, whose outer contour approximately corresponds to the profiling at 11 on the workpiece 1. In any case, a similar contour should be present. Hot compressed air 8 is introduced into the forming device 5 and reaches the forming element 5a. This is heated due to the heat transfer from the hot compressed air 8 to the forming element 5a. On the other side, the forming element 5a has openings, at least on the side facing the edge band 2, which allow the hot compressed air 8 to escape through these openings in the direction of the edge band 2. As a result, a compressed air cushion is built up around the forming element 5a. As the process continues (cf. Fig. 4) of the feed of the edge band in direction F, it is brought closer to the shaping element 5a or closer to the workpiece 1. As a result, the edge band reaches the effective range of the shaping element 5a and is heated and thus made deformable, as can be seen, for example, in Fig. 6 recognizes. In Fig. 7 Finally, it can be seen how, due to the oblique contour guidance of the shaping element 5a or the shaping device 5 relative to the feed direction P or direction X, the deformed edge band 2 located in the effective range of the shaping device 5 is gradually guided closer to the narrow side of the workpiece 1 and into the recess between L1 and L2.

[0019] After the edge band 2 has left the effective area of ​​the forming device 5, the edge band is then pressed or joined to the narrow side of the workpiece 1 using known pressing tools. In order for the joining to work, before the edge band 2 is pressed onto the workpiece 1, either between the effective area in the feed section 12 (cf. Fig. 4 ) and the joining area F of the edge band 2 in the effective area or on the side of the effective area facing away from the joining area on the side of the edge band to be joined to the workpiece 1, the edge band must either be provided with an adhesive, melted or / and the workpiece must be coated accordingly with an adhesive layer.

[0020] Because a compressed air cushion forms around the forming element 5a, the edge band 2 and the forming element 5a are kept at a distance due to this compressed air cushion and thus direct contact between the decorative side of the edge band, i.e. the visible side of the edge band 2 which is on the outside in the joined state, and the forming element is reduced or avoided, so that traces on the decorative side cannot occur or only marginally occur during forming.

Claims

1. Device (3) for applying an edge band (2) to the narrow sides (11) of plate-shaped workpieces (1) made of wood or wood substitute, wherein the device (3) comprises an edge band feed device which transports an edge band (2) via a feed path (12) in the direction of a workpiece (1) to a joining area (F) in which the edge band (2) is joined to the workpiece (1), and a forming device (5) which has a forming element (5a), in particular a forming rod, and is designed to give the edge band (2) a shape which deviates from the flat shape, in particular a curved shape, viewed in cross-section relative to its longitudinal direction, characterized by thatthe forming device (5) is connected to a compressed air supply (8) which provides hot compressed air, wherein the forming device (5) comprises at least one compressed air line means which guides the supplied hot compressed air into the forming element (5a), wherein the forming element (5a) has air outlet openings via which the hot compressed air fed into the forming element (5a) can exit from the forming element (5a).

2. Device (3) according to claim 1, characterized by that the forming device (5) is positioned along the feed path (12) in such a way that an edge band (2) transported along the feed path (12) reaches the effective area of ​​the forming device (5).

3. Device (3) according to claim 2, characterized by that the effective range of the forming device (5) extends to or just before the joining area (F).

4. Device (3) according to one of the preceding claims, characterized by that the shaping element (5a) has an outer contour which corresponds to a negative form of a contour to be given to the edge band (2).

5. Device (3) according to one of the preceding claims, characterized by that the air outlet openings are present at least on the side of the shaping element (5a) facing the feed path (12). 6.Method for processing an edge band (2), in which a device (3) according to one of the preceding claims is used, the method comprising the following steps: a. an edge band (2) is provided; b. the edge band (2) is transported along the feed path (12) in the direction of a workpiece (1) or joining region (F); c. the edge band (2) is heated and formed along the feed path with the forming device (5) by introducing hot compressed air; d. the edge band (2) thus heated is joined to the narrow side of the workpiece (1).

6. Method according to claim 6, characterized by that the edge band (2) is transported in the area of ​​the feed section (12) through the effective area of ​​the forming device (F) and is heated by hot compressed air emerging from the openings of the forming element (5a) and is brought to the profiled narrow side of the workpiece (1) to be edged. 7.Method according to one of claims 6 or 7, characterized by that the edge band is joined to the narrow side of the workpiece (1) in step d. by a pressure roller (6) and / or a pressure shoe pressing the edge band (2) against the narrow side.

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