ADHESIVE MELTING DEVICE FOR AN EDGE BANDING MACHINE

Description

[0001] The invention relates to an adhesive melting device for an edge banding machine, wherein the adhesive melting device has a melting chamber for receiving adhesive material to be melted, a melting device with an electrically heatable melting body for melting the adhesive material and a pressure piston movable in a feed direction for pressing the adhesive material located in the melting chamber against the melting body, wherein the melting body comprises a plurality of through-channels which extend in the feed direction and each have an inlet section facing the melting chamber and an outlet section facing away from the melting chamber.

[0002] Such adhesive melting devices are used in edgebanding machines, with the aid of which a glued edge, often also referred to as a "edge band," can be fed to one long side of a workpiece moving in a transport direction and glued to the long side. The workpiece with the glued edge is then usually fed to a post-processing station to achieve a continuous transition between the top and bottom sides of the workpiece and the edge band.

[0003] To bond the edgeband to the long side of the workpiece, the adhesive is melted using an adhesive melting device. The melted adhesive can then be fed into an adhesive application system on the edgebander to apply the adhesive to the long side of the workpiece, allowing the edgeband to be subsequently bonded to the long side.

[0004] Adhesive melting devices of the type mentioned above have a melting chamber into which adhesive material to be melted can be introduced. Furthermore, the adhesive melting devices have a melting device for melting the adhesive material. The melting device has an electrically heatable melting body comprising a plurality of through-channels, each having an inlet section facing the melting chamber and an outlet section facing away from the melting chamber. Furthermore, the adhesive melting devices have a pressure piston movable in a feed direction, with the aid of which the adhesive material introduced into the melting chamber can be pressed against the melting body in order to melt the adhesive material. The through-channels extend in the feed direction of the pressure piston. The molten adhesive material can be fed to the adhesive application system via the through-channels.

[0005] Such adhesive melting devices are known, for example, from EP 3 403 728 A1.

[0006] From EP 3 653 308 A1 an adhesive melting device with the features of the preamble of patent claim 1 is known.

[0007] The object of the present invention is to further develop an adhesive melting device of the type mentioned at the outset in such a way that the adhesive material can be melted within a shorter time.

[0008] This object is achieved by an adhesive melting device having the features of patent claim 1.

[0009] The adhesive material introduced into the melting chamber can be pressed against the honeycomb structure of the melting body by means of the pressure piston. The honeycomb structure faces the melting chamber and forms a large surface area through which rapid heat transfer from the electrically heated melting body to the adhesive material can occur. This allows the adhesive material to melt within a short time. Furthermore, the honeycomb structure has the advantage that the melting body can be easily cleaned.

[0010] The honeycomb structure comprises a multitude of polygonal cells, each forming an entrance section of a through-channel and separated from each other by partition walls. Heat transfer from the heated melt body to the adhesive material can occur via the partition walls. The partition walls can have flat surfaces, at least in some areas, without recesses or undercuts. This reduces the risk of adhesive residues forming within the honeycomb structure.

[0011] At least some of the cells are hexagonal in shape.

[0012] It is particularly advantageous if the hexagonal cells each have two opposite and parallel long sides which are integrally connected to one another via two pairs of narrow sides aligned at an angle to one another, the long sides being longer than the narrow sides.

[0013] In particular, it can be provided that the two pairs of narrow sides are designed identically and that the two long sides are designed identically.

[0014] It has proven advantageous if the long sides are at least twice as long as the short sides.

[0015] In a preferred embodiment of the invention, each of the cells of the honeycomb structure transitions continuously in the feed direction into a round, in particular circular, cross-sectional exit section of a through-channel. In such a configuration, each cell of the honeycomb structure is adjoined by a round, cross-sectional exit section of a through-channel, with the transition from the cells to the round exit sections being continuous. The through-channels thus have no steps or recesses where adhesive residues could form and complicate cleaning of the melt body.

[0016] It is advantageous if the polygonal cells of the honeycomb structure taper continuously in the feed direction. With such an embodiment of the invention, the flow cross-section of the polygonal cells continuously decreases in the feed direction. This results in a continuous increase in the flow velocity of the adhesive material. This counteracts the formation of so-called dead spots within the cells, where the flow velocity drops to zero. Such dead spots could lead to thermal decomposition or hardening of the adhesive material, which could result in the formation of adhesive residues within the cells.

[0017] It is advantageous if the exit sections of the through-channels, which have a round cross-section, especially a circular cross-section, taper continuously in the feed direction. This leads to a continuous reduction in the flow cross-sections in the area of ​​the exit sections and thus to an increasing flow velocity of the adhesive material in the exit sections. This counteracts the formation of adhesive residues in the exit sections.

[0018] It is particularly advantageous if the through channels taper continuously over their entire length.

[0019] In an advantageous embodiment of the invention, the melting device comprises, in addition to the melting body, a collecting body which adjoins the melting body in the feed direction. The collecting body has several collecting channels into which the through-channels of the melting body open and which guide the molten adhesive material to an outlet area of ​​the collecting body. The molten adhesive material can flow from the through-channels of the melting body to an outlet area of ​​the collecting body via the collecting channels. The collecting channels can be designed to be aerodynamically efficient.

[0020] It is advantageous if the collecting body can be detachably connected to the melting body. This allows the collecting body to be separated from the melting body, for example, for cleaning purposes.

[0021] At least one through channel leads into each collecting channel. Preferably, several through channels lead into each collecting channel.

[0022] It is advantageous if several through-channels lead consecutively into the collecting channels toward the outlet area, and the flow cross-section of the collecting channels increases toward the outlet area. The increasing flow cross-section of the collecting channels toward the outlet area allows the collection of an increasing amount of molten adhesive material toward the outlet area, which is fed to the collecting channels via the through-channels. The flow velocity of the adhesive material within the collecting channels remains virtually unchanged despite the increasing amount of adhesive material. The flow behavior of the adhesive material is therefore not impaired by the fact that several through-channels lead into the collecting channels.

[0023] In a preferred embodiment of the invention, the collecting channels have a width and / or depth that increases towards the outlet area.

[0024] It is advantageous if the width and / or depth of at least one collecting channel increases continuously over its entire length.

[0025] It is advantageous if the collecting channels are aligned perpendicular to the through channels.

[0026] In a preferred embodiment of the invention, the collecting body forms a collecting plate which has a front side facing the melting body and a rear side facing away from the melting body, wherein the collecting channels are arranged in the form of depressions on the front side.

[0027] Preferably, the front and back of the collecting plate are flat.

[0028] It is advantageous if the back of the collecting plate is aligned parallel to the front of the collecting plate.

[0029] In a particularly preferred embodiment of the invention, the adhesive melting device has an outlet body, wherein the melting device is detachably connectable to the outlet body, wherein the collecting body is arranged between the melting body and the outlet body, and wherein the outlet body has an outlet opening for the molten adhesive material aligned with the outlet region of the collecting body. Via the collecting channels and the outlet region of the collecting body, the molten adhesive material can reach the outlet opening of the outlet body, from which the adhesive material can be fed into an adhesive application system, with the aid of which the adhesive material can be applied to a longitudinal edge of a workpiece moving in a transport direction. For maintenance purposes, in particular for cleaning, the melting device can be separated from the outlet body.

[0030] The area of ​​the rear side of the melting body, against which the collecting body rests with its side facing the melting body, and / or the area of ​​the front side of the outlet body, against which the collecting body rests with its side facing the outlet body, are preferably designed to be flat.

[0031] It is advantageous if the collecting body can be detachably connected to the melting body and the outlet body. This facilitates maintenance, especially cleaning, of the melting device.

[0032] The following description of an advantageous embodiment of the invention serves to explain it in more detail in conjunction with the drawings. They show: Figure 1: a perspective view of an adhesive melting device for an edge banding machine; Figure 2: an exploded view of a melting device and an outlet body of the adhesive melting device from Figure 1; Figure 3: a perspective view of the melting device, viewed diagonally from the front; Figure 4: a perspective view of the melting device, viewed diagonally from the rear; Figure 5: a sectional view of a melting body of the melting device; Figure 6: a sectional view of a collecting body of the melting device.

[0033] The drawing schematically shows an advantageous embodiment of an adhesive melting device 10 according to the invention, which is used in an edge banding machine. Such edge banding machines are known to those skilled in the art. Figure 1An adhesive application system 12 of the edge banding machine is shown schematically. The adhesive melting device 10 is connected to the adhesive application system 12. With the aid of the adhesive melting device 10, an adhesive material can be melted; this will be explained in more detail below. By means of the adhesive application system 12, the molten adhesive material can be applied to a long side 16 of a workpiece 18. For this purpose, the adhesive application system has a nozzle body 14. The workpiece 18 can be moved in a transport direction 20 by means of transport elements known per se and therefore not shown in the drawing, for example by means of transport rollers or transport chains. After the adhesive material has been applied to the long side 16, a glued edge can be glued to the long side 16 by means of the edge banding machine in a known manner.

[0034] The adhesive melting device 10 has a melting chamber 22 into which the adhesive material to be melted can be introduced. The adhesive material to be melted can be configured, for example, in the form of an adhesive cartridge or in the form of adhesive granules.

[0035] The adhesive melting device 10 also has a melting device 24 and an outlet body 25. The melting device 24 is in the Figures 2 to 6 shown schematically. Figure 2 also schematically shows the outlet body 25. With the aid of the melting device 24, the adhesive material introduced into the melting chamber 22 can be melted, and with the aid of the outlet body 25, the molten adhesive material can be fed into the adhesive application system 12. The outlet body 25 forms an interface between the melting device 24 and the adhesive application system 12.

[0036] The adhesive melting device 10 has a pressure piston 26, which can be moved in a feed direction 30 by means of a feed unit 28. With the help of the pressure piston 26, the adhesive material introduced into the melting chamber 22 can be pressed against the melting device 24. The feed unit 28 can be configured, for example, as a piston-cylinder unit or, for example, as an electric motor. Such feed units 28 are known to those skilled in the art.

[0037] The melting device 24 has a melting body 32 and a collecting body 34, which are arranged one behind the other in the feed direction 30. The outlet body 25 adjoins the collecting body 34 in the feed direction 30, this is shown in Figure 2 clearly.

[0038] The melting body 32 has a plurality of through-channels 38 that extend in the feed direction 30 and each have an inlet section 40 facing the melting chamber 22 and an outlet section 42 facing away from the melting chamber 22. The inlet sections 40, as a whole, form a honeycomb structure 44 facing the melting chamber 22.

[0039] The honeycomb structure 44 has a plurality of polygonal cells 46, each forming an inlet section 40 of a through-channel 38 and separated from one another by partition walls 48. In the feed direction 30, each cell 46 is adjoined by an outlet section 42 of a through-channel 38, which extends to a flat rear side 50 of the melt body 32.

[0040] As is particularly evident from Figure 2 and 3As is clear, several of the cells 46 are hexagonal in shape and have two opposing and parallel longitudinal sides 52, 54, which are integrally connected to one another via a first pair of narrow sides 56, 58 and a second pair of narrow sides 60, 62, wherein the narrow sides 56, 58 are arranged at an angle to one another and wherein the narrow sides 60, 62 are also arranged at an angle to one another. The longitudinal sides 52, 54 are significantly longer than the narrow sides 56, 58, 60, 62. In the illustrated embodiment, the longitudinal sides 52, 54 are more than twice as long as the narrow sides 56, 58, 60, 62.

[0041] The cross sections of the outlet sections 42 of the through-channels 38 are round; in the illustrated embodiment, they are circular. Both the inlet sections 40 in the form of the cells 46 and the adjoining outlet sections 42 taper continuously in the feed direction 30, with the transition from the cells 46 to the outlet sections 42 also occurring continuously. Thus, the flow cross section of the through-channels 38 decreases continuously in the feed direction 30. This is particularly evident from Figure 5This decreases significantly. The decreasing flow cross-section results in a continuous increase in the flow velocity of the adhesive material. This counteracts the risk of so-called dead spots forming within the through-channels 38, where the flow velocity drops to zero and where thermal decomposition or curing of the adhesive material could occur. The risk of adhesive residues forming within the through-channels 38 is therefore very low.

[0042] The melting body 32 can be heated electrically. For this purpose, it has several cylindrical recesses 64 arranged between the outlet sections 42 of the through-channels 38, each of which can accommodate an electric heating cartridge. Such heating cartridges are known per se to those skilled in the art and are therefore not shown in the drawings for the sake of clarity.

[0043] The honeycomb structure 44 enables rapid heat transfer from the electrically heated melting body 32 to the adhesive material. The adhesive material can therefore be melted within a short time.

[0044] As already mentioned, the through-channels 38 extend to the rear side 50 of the melting body 32. The rear side 50 is flat, and the collecting body 34 rests against the rear side 50.

[0045] The collecting body 34 forms a collecting plate 66 and has a plurality of collecting channels 68, 70, 72, 74, 76, which are designed in the form of depressions and into which a plurality of through-channels 38 each open. Via the collecting channels 68, 70, 72, 74, 76, the molten adhesive material can flow from the through-channels 38 to an outlet region 78 of the collecting body 34.

[0046] The flow cross-section of the collecting channels 68, 70, 72, 74, 76 increases in the direction of the outlet area 78. For this purpose, the collecting channels 68, 70, 72, 74, 76 widen and / or deepen as they approach the outlet area 78. This is particularly evident from Figure 6 The increasing flow cross-section of the collecting channels 68, 70, 72, 74, 76 toward the outlet area 78 allows the intake of an increasing amount of molten adhesive material, which is fed to the collecting channels 68, 70, 72, 74, 76 via the through-channels 38, while the flow velocity of the adhesive material within the collecting channels 68, 70, 72, 74, 76 remains virtually unchanged despite the increasing amount of adhesive material. The flow behavior of the adhesive material is therefore not impaired by the fact that several through-channels 38 open into each collecting channel.

[0047] The collecting plate 66 has a flat front side 79 facing the melting body 32 and a flat rear side 80 facing away from the melting body 32. The collecting channels 68, 70, 72, 74, 76 are arranged in the form of recesses on the front side 79. The rear side 80 is aligned parallel to the front side 79. With its rear side 80, the collecting plate 66 rests against a flat front side 82 of the outlet body 25, which has an outlet opening 84 aligned with the outlet region 78 of the collecting body 34, through which the molten adhesive material can be fed into the adhesive application system 12. For this purpose, the adhesive application system 12 has a connecting channel 86, which adjoins the outlet opening 84 and via which the molten adhesive material can be fed to the nozzle body 14.

[0048] With the aid of the adhesive melting device 10, the adhesive material can be melted within a short time and fed to the adhesive application system 12. The melting device 24 can be easily cleaned. For this purpose, the melting body 32, the collecting body 34, and the outlet body 25 are detachably connected to one another.

Claims

1. Adhesive melting apparatus for an edge-banding machine, wherein the adhesive melting apparatus (10) comprises a melt chamber (22) for accommodating adhesive material to be melted, a melting device (24) having an electrically heatable melting body (32) for melting the adhesive material, and a pressing piston (26) that is movable in a feed direction (30) for pressing the adhesive material located in the melt chamber (22) against the melting body (32), wherein the melting body (32) comprises a multitude of through-channels (38), which extend in the feed direction (30) and each comprise an inlet portion (40) pointing toward the melt chamber (22) and an outlet portion (42) pointing away from the melt chamber (22), wherein the inlet portions (40) form a honeycomb structure (44), wherein the honeycomb structure (44) comprises a multitude of polygonal cells (46), which each form an inlet portion (40) of a through-channel (38) and are separated from one another by separating walls (48), characterized in that at least some of the cells (46) are of hexagonal configuration.

2. Adhesive melting apparatus in accordance with Claim 1, characterized in that the hexagonal cells (46) each comprise two opposite longitudinal sides (52, 54) oriented in parallel with one another, which are connected to one another in one piece by way of two pairs of narrow sides (56, 58; 60, 62) oriented at an angle to one another, wherein the longitudinal sides (52, 54) are longer than the narrow sides (56, 58, 60, 62).

3. Adhesive melting apparatus in accordance with Claim 2, characterized in that the longitudinal sides (52, 54) are at least twice as long as the narrow sides (56, 58, 60, 62).

4. Adhesive melting apparatus in accordance with any one of Claims 1 to 3, characterized in that each of the polygonal cells (46) of the honeycomb structure (44) transitions continuously in the feed direction (30) into an outlet portion (42) of a through-channel (38), said outlet portion (42) being round in cross-section.

5. Adhesive melting apparatus in accordance with Claim 4, characterized in that the polygonal cells (46) taper continuously in the feed direction (30).

6. Adhesive melting apparatus in accordance with Claim 4 or 5, characterized in that the outlet portions (42) of the through-channels (38), said outlet portions (42) being round in cross-section, taper continuously in the feed direction (30).

7. Adhesive melting apparatus in accordance with any one of the preceding Claims, characterized in that the through-channels (38) taper continuously over their entire length.

8. Adhesive melting apparatus in accordance with any one of the preceding Claims, characterized in that the melting device (24) comprises a collection body (34), which adjoins the melting body (32) in the feed direction (30), wherein the collection body (34) comprises a plurality of collection channels (68, 70, 72, 74, 76) into which the through-channels (38) of the melting body (32) open and which guide the molten adhesive material to an outlet region (78) of the collection body (34).

9. Adhesive melting apparatus in accordance with Claim 8, characterized in that a plurality of through-channels (38) open successively into the collection channels (68, 70, 72, 74, 76) in the direction of the outlet region (78) and the flow cross-section of the collection channels (68, 70, 72, 74, 76) increases in the direction of the outlet region (78).

10. Adhesive melting apparatus in accordance with Claim 9, characterized in that the collection channels (68, 70, 72, 74, 76) have a width and / or depth that increases in the direction of the outlet region (78).

11. Adhesive melting apparatus in accordance with Claim 10, characterized in that the width and / or depth of at least one collection channel (68, 70, 72, 74, 76) increases continuously over the entire length thereof.

12. Adhesive melting apparatus in accordance with any one of Claims 8 to 11, characterized in that the collection body (34) forms a collection plate (66), which comprises a front side (79) facing toward the melting body (32) and a rear side (80) facing away from the melting body (32), wherein the collection channels (68, 70, 72, 74, 76) are arranged in the form of recesses on the front side (79).

13. Adhesive melting apparatus in accordance with any one of Claims 8 to 12, characterized in that the adhesive melting apparatus (10) comprises an outlet body (25), wherein the melting device (24) is releasably connectable to the outlet body (25), wherein the collection body (34) is arranged between the melting body (32) and the outlet body (25), and wherein the outlet body (25) comprises an outlet opening (84) for the molten adhesive material, said outlet opening (84) being oriented in alignment with the outlet region (78) of the collection body (34).