DEVICE FOR REMOVAL OF HOT HOT ADHESIVE

Description

Technical field

[0001] The present invention relates to a device for removing hot melt adhesive on a rotating vertically arranged roller, in particular for use on a roller application system for processing hot melt adhesives on edge banding machines. State of the art

[0002] Roller application systems for processing hot melt adhesives are generally used on edge banding machines. This means that such systems transfer heated, viscous adhesives of various types and chemical compositions to wood-like or at least partially wood-based workpieces. For example, such roller application systems can be used to enable the automatic and rapid attachment of plastic or wooden edges to a workpiece.

[0003] When changing from typically used ethylene-vinyl acetate or polyolefin adhesives to, for example, polyurethane, the roller application system must be drained and cleaned, as mixing the adhesive is counterproductive and undesirable due to the different chemical properties and different temperatures. A similar cleaning and draining step on a roller application system is also necessary when changing the adhesive color.

[0004] Previously, during cleaning and / or replacement, the roller application system was removed from the edge banding machine and emptied and cleaned of any remaining adhesive by an operator next to the machine. However, this process is complex and time-consuming. Furthermore, hot melt adhesive residues can remain on the roller of the roller application system, which is used to apply the hot melt adhesive to workpieces.

[0005] Another complex solution for emptying and cleaning a roller of a certain type of hot melt adhesive involves scraping the adhesive off using a slider integrated into a drip tray. However, this design cannot prevent the adhesive from spreading unevenly in the drip tray, so the operator must correct this using a tool. The uneven distribution of the adhesive in the drip tray can also cause the adhesive to overflow from the drip tray, which can lead to clogging and contamination of the edge banding machine.

[0006] Another previously known solution for automatically emptying and cleaning roller application systems on edge banding machines with vertical roller arrangements simply involves draining the remaining adhesive downwards. However, this is extremely disadvantageous, as current machines with roller application systems typically have limited space, particularly in the lower machine area, making the removal of excess and worn-out adhesive usually complicated and time-consuming. In the event of irregularities or excessive hot melt adhesive, this can result in the entire roller application system having to be removed with the aid of additional tools to prevent further contamination of the edge banding machine. Furthermore, draining the hot melt adhesive in this way is extremely time-consuming.

[0007] Previously known devices for removing hot melt adhesive are also known from EP 3 406 409 A1, which forms the basis for the two-part version of independent claim 1, as well as from US 2016 / 214151 A1, EP 2 610 192 A1, DE 11 11 562 B, DE 26 52 133 C2 and US 2009 / 035037 A1. Description of the invention

[0008] It is therefore an object of the present invention to provide a device for removing hot melt adhesive from a rotating vertically arranged roller, which enables fast, simple and complete removal of hot melt adhesive from a roller - for example, on a roller application system of an edge banding machine - without additional tools or additional conveyor systems.

[0009] This object is achieved by a device having the features of claim 1. Preferred embodiments can be found in the further claims, the following descriptions and the drawings.

[0010] According to the invention, the device for removing hot melt adhesive has a hollow body-shaped scraper on a rotating vertically arranged roller.

[0011] The term "hollow body" generally refers to an internally hollow, hollowed-out object that has no edges in its basic shape. This preferably refers to an elliptical or oval body. A hollow cylindrical scraper is particularly preferred.

[0012] Furthermore, the scraper has an opening on its circumferential surface along the longitudinal axis, at which opening a radially outwardly projecting impact plate is arranged, and the impact plate is arranged such that it can be brought into a position for removing adhesive from the roller and can convey the removed adhesive to the circumferential inner side of the scraper.

[0013] The "opening" is to be understood as a slot or continuous milling in the surface of the scraper, so that the removed adhesive, which can be detached from the roller by means of the impact plate during removal / cleaning of the roller, can be conveyed into the interior of the scraper.

[0014] Furthermore, a drain is arranged in the upper half along the longitudinal axis of the scraper, preferably at the vertically upper end of the scraper.

[0015] According to such a design, it is possible for adhesive which has been removed from the roller to be conveyed by the design of the scraper into its circumferential inner side and to be removed and conveyed away by means of the back pressure which is increased by trailing, viscous adhesive material in the interior of the scraper.

[0016] In other words, the invention is based on the basic idea of ​​conveying the removed hot melt adhesive quickly, easily and continuously against the force of gravity (i.e. in the vertical direction) away from the roller, for example a roller application system of an edge banding machine, by means of the dynamic pressure generated inside the scraper and the resulting hot melt adhesive vortex on the circumferential inner side of the scraper.

[0017] This means that the design of the device allows for a constant and continuous removal process. The scraper maintains a constant back pressure inside the scraper, creating a vortex on the inner circumference due to the constant adhesive feed achieved, allowing the removed hot melt adhesive material to be conveyed away inside the scraper against the back pressure and against gravity. Since this occurs against gravity and therefore does not have to occur vertically on the underside of a machine, this ensures better accessibility for emptying the removed material. Furthermore, the design of the scraper with an opening and an attached impact plate makes it possible to remove the hot melt adhesive material without additional tools or other devices.In addition, no electricity or cable routing is necessary, since the hot melt adhesive can be conveyed away from the roller against gravity solely by the structural design of the device, in particular by the resulting vortex flow on the inner wall.

[0018] Such a design makes it possible to convey the hot melt adhesive, which is conveyed upwards by the vortex on the inner wall of the scraper against gravity, to the outside in a controlled manner. This means that the scraper takes the adhesive from the roller as the roller rotates and conveys it upwards along the inner wall of the scraper with the vertically arranged roller to the upper edge of the scraper. The emptying process can then take place fully automatically via the drain. This means that the drain, which is particularly preferably arranged vertically at the upper end of the scraper, ensures that the hot melt adhesive emerging from the scraper is safely transported away without the need for additional conveying devices or the like.This ensures that no component needs to be removed from the machine in advance to change the adhesive or clean the (application) roller; only a simple device is required.

[0019] According to a further development of the invention, the scraper has a base element, with the scraper being arranged starting from the base element. This results in a particularly effective conveyance of the removed adhesive. According to a further aspect, the opening of the scraper extends over its entire length.

[0020] According to such an embodiment, it is possible to prevent side streams or misdirected hot melt adhesive flows, for example, within a roller application system. In other words, this ensures that the removed hot melt adhesive can be completely conveyed into the interior of the scraper and can be transported upwards against gravity using the above-described back pressure and the resulting vortex. Misdirected, removed hot melt adhesive flows can thus be prevented within the roller application system.

[0021] According to a further aspect, the engagement angle between the roller and the impact plate for removing the adhesive to the inside of the scraper is an acute angle. This angle can, for example, preferably be less than 75°, particularly preferably 50°, and even more preferably less than 30°.

[0022] The "angle of engagement" between the roller and the butt plate is understood to be the angle resulting from a tangent at the point of engagement between the butt plate and the roller or the adhesive layer on the roller and the butt plate itself in the direction of this tangential to the roller.

[0023] Such a design with an acute engagement angle allows for minimal deflection of the adhesive. This ensures that the adhesive flow can be guided continuously and in a concentrated manner without any irregularities occurring. Furthermore, the acute angle between the two components engaging during removal ensures easy detachment of the hot melt adhesive from the roller.

[0024] According to a further aspect, the drain is connected to a heat-resistant drip tray.

[0025] According to such an embodiment, it is possible for the hot melt adhesive to be conveyed away from the roller (for example, the roller application system of an edge banding machine). This means that the hot melt adhesive can be removed from the roller within a few minutes, allowing the roller to be either emptied or the adhesive to be changed. Furthermore, the excess hot melt adhesive can be automatically collected in the heat-resistant drip tray. This makes it possible to increase productivity and reduce maintenance work or cleaning steps for cleaning the roller or changing the hot melt adhesive. The heat-resistant drip tray itself can be easily removed from the device. It is preferred that the heat-resistant drip tray be designed to be reversible.This means that the heat-resistant drip tray containing the hot melt adhesive can be removed from the hot melt adhesive removal device and can be reused after cleaning the heat-resistant drip tray.

[0026] According to a further aspect, the device for removing hot melt adhesive is made at least in sections from injection molding.

[0027] Such a design makes it possible to reduce the costs of such a device and design the entire device as a disposable product. This means that after the hot melt adhesive has been removed from the vertically arranged roller, the device can be easily removed and disposed of completely.

[0028] According to a further aspect, at least the surface of the impact plate and / or the circumferential inner side of the wiper may comprise an adhesion-reducing material.

[0029] Such a design allows for the removal of the hot melt adhesive to occur with particularly low friction, allowing the hot melt adhesive to be conveyed particularly easily into the interior of the scraper. The vortex created on the inner surface then allows the hot melt adhesive to be removed to be conveyed away from the roller with low friction and upwards out of the scraper against gravity.

[0030] In addition, it is possible for the device for removing hot melt adhesive to be designed to be reusable.

[0031] Examples of such an adhesion-reducing material include Teflon-coated aluminum. Simple non-stick surface treatments of aluminum or other materials themselves can also be used for this purpose.

[0032] According to a further aspect of the present disclosure, a roller application system for applying hot melt adhesive to a workpiece, which preferably consists at least in sections of wood, wood-based materials, plastic or the like, can be configured with a device for removing hot melt adhesive and with a roller for applying hot melt adhesive to a workpiece.

[0033] Preferably, the scraper extends at least over the entire length of the roller.

[0034] Such a configuration allows the device for removing hot melt adhesive to be designed particularly simply. Furthermore, the device's attachment is greatly simplified, as it does not need to be moved to remove the hot melt adhesive. Instead, a simple pin can be used to secure it against slipping away from the roller from which the adhesive is to be removed.

[0035] Furthermore, the design of the scraper over the entire length of the roller means that the hot melt adhesive can be removed and the roller cleaned particularly quickly, in particular within a few minutes.

[0036] Furthermore, no complex preparation is required, as the device for removing hot melt adhesive operates purely mechanically, requiring no controls or similar activation. This ensures simple, complete, and rapid removal of hot melt adhesive on a rotating, vertically arranged roller.

[0037] According to a further aspect of the disclosure, an edge banding machine may comprise, in addition to the roller application system just described, an edge feeding device which is designed such that it can feed plastic or wooden edges to a workpiece which preferably consists at least in sections of wood, wood-based materials or the like at an identical speed to a workpiece conveying speed. Brief description of the drawings

[0038] The following schematic drawings illustrate a device for removing hot melt adhesive on a rotating, vertically arranged roller. Such devices are used, for example, in edge banding machines or generally in roller application systems for processing hot melt adhesives. They show: Figure 1: A schematic plan view of a device for removing hot melt adhesive on a rotating vertically arranged roller according to an exemplary embodiment. Figure 2 : A schematic side view of the device for removing hot melt adhesive on a rotating vertically arranged roller. Description of the preferred embodiments

[0039] Figure 1of the present application shows a plan view of a device for removing hot melt adhesive from a rotating, vertically arranged roller. In particular, the plan view clearly shows that a roller 1 is engaged with a cylindrical scraper 2 of the device in order to remove hot melt adhesive from the roller 1. In the plan view of the device, it can be seen that the surface of the roller 1, which rotates in direction A, is coated with the hot melt adhesive. This roller is arranged, for example, in a roller application system for processing hot melt adhesives and serves, for example, to apply heated viscous adhesive of various types to wood-like or at least partially wooden workpieces during normal operation.An example application for this is an edge banding machine, in which adhesive is applied next to a parallel guided workpiece and a plastic or wooden edge is bonded to the workpiece.

[0040] The Figure 1 The device shown for removing hot melt adhesive from such a rotating roller generally fulfills two functions or has two applications. A first application is the complete cleaning of the application roller in the application system. A second application is when changing the adhesive on the roller. This means that the remaining adhesive on the roller can be safely and reliably removed by the device for removing hot melt adhesive in every application. To ensure this, Figure 1In the exemplary embodiment of the device for removing hot melt adhesive shown, a rotating vertically arranged roller 1 comes into contact with the cylindrical scraper 2 of the device.

[0041] In particular, the contact between the roller 1 and the cylindrical scraper 2 is established via a shock plate 3 attached to the cylindrical scraper 2. As can be seen from Figure 1 As can be clearly seen, the adhesive on the outer peripheral surface of the roller 1 is detached from the roller surface by the butt plate 3, which is arranged at an acute angle α to the roller surface. In other words, the butt plate 3, which is arranged at an acute angle to the roller surface, comes into contact with the roller surface of the roller 1 and thus releases the adhesion of the hot melt adhesive from the surface of the roller. 1.

[0042] Out of Figure 2It is clearly evident that, in the preferred embodiment, the impact plate 3 extends over the entire length of the roller 1. Thus, the cylindrical scraper 2 does not need to be moved to remove the hot melt adhesive, and the hot melt adhesive is removed across the entire longitudinal axis of the roller in one step by rotating the roller. Furthermore, the scraper 2 is closed by a base element 7 at its lower longitudinal end.

[0043] Furthermore, Figure 2 of the present application that a drain 4 is arranged at the vertically upper end of the cylindrical scraper.

[0044] This outlet 4 serves to transport excess hot melt adhesive from the cylindrical scraper 2. Furthermore, the outlet 4 shown in the exemplary embodiment is connected to a collecting tray 5. It is preferred that the collecting tray 5 be heat-resistant.

[0045] The following explains the operation of the device for removing hot melt adhesive on a rotating vertically arranged roller.

[0046] During normal operation of the roller 1, for example in an edge banding machine, the device for removing hot melt adhesive is arranged at a distance from the rotating, vertically arranged roller 1.

[0047] However, if cleaning and emptying of the roller 1 is performed, for example, to perform an adhesive change, the hot melt adhesive removal device is used on the rotating, vertically arranged roller 1. For this purpose, the device is positioned on the roller 1 such that the impact plate 3 comes into contact with the outer peripheral surface of the roller 1. The position of the hot melt adhesive removal device is ensured, for example, by a simple pin on the roller.

[0048] It is preferred that the surface of the roller 1 is in contact with the impact plate 3 at an engagement angle α. Particularly preferred is an acute angle between a tangent running along the contact line between the roller 1 and the impact plate 3 and the impact plate 3 itself. By contacting the surface of the roller 1 with the impact plate 3, the conveying direction of the hot melt adhesive can be manipulated via the surface of the impact plate (see Figure 1 ).

[0049] In the next step, the impact plate 3 can detach the hot melt adhesive from the roller 1 while the roller is rotating and convey it into the interior of the cylindrical scraper 2 opposite to the direction of rotation A of the roller 1.

[0050] As the adhesive is increasingly conveyed into the cylinder interior of the scraper 2 through the opening 6 of the cylindrical scraper 2, the back pressure within the cylinder of the scraper 2 increases.

[0051] By conveying the hot melt adhesive in the opposite direction to the direction of rotation of the roller 1 (direction C), it is possible, with the progressive rotation of the roller 1, to convey the removed hot melt adhesive by means of the device in a vertical direction upwards (see arrow B in Figure 2 ) to promote.

[0052] Due to the resulting vortex inside the cylinder of the scraper 2, the removed hot melt adhesive can be easily and easily conveyed upwards against gravity without additional conveying devices.

[0053] In a final step, the removed hot melt adhesive material is collected at the upper vertical end of the cylindrical scraper 2 via a drain 4 in the heat-resistant collecting tray 5.

[0054] After completing the cleaning of the roller 1, the hot melt adhesive removal device according to the exemplary embodiment can be completely detached from the roller 1 and can remain in the roller application system at a distance from the roller 1. The removed hot melt adhesive can be removed and disposed of through the collecting tray 5 arranged on top of the cylindrical scraper 2.

[0055] In a further exemplary embodiment not shown, the device for removing hot melt adhesive can also consist of several sequential scrapers 2 which extend proportionally over the entire length of the roller.

[0056] According to such a design, it is possible for hot melt adhesive to be removed simultaneously over the entire length of the roller by several individual components. This allows the diameter of the scraper to be reduced, and the hot melt adhesive can be removed at several points simultaneously. This reduces the time until sufficient back pressure has built up within the scraper to create a vortex, and the removal of the hot melt adhesive can be further accelerated, or the removal time can be shortened. List of reference symbols

[0057] 1 Roller 2 Scraper 3 Impact plate 4 Drain 5 Collecting tray 6 Opening 7 Base element A Direction of rotation of roller C Direction of rotation of adhesive inside the scraper (vertical) α Pressure angle between roller and impact plate

Claims

1. Device for removing hot-melt adhesive on a rotating vertically arranged roller (1) which has a scraper (2) in the form of a hollow body, preferably in the form of a hollow cylinder, which scraper has an opening (6) along the longitudinal axis on its circumferential surface, at which opening a radially outwardly projecting baffle plate (3) is arranged, and wherein the baffle plate (3) is arranged in such a way that it can brought into a position for removing adhesive from the roller (1) and can convey the removed adhesive to the inner circumferential side of the scraper (2), characterised in that a drain (4) is arranged in the upper half along the longitudinal axis of the scraper (2), preferably at the vertically upper end of the scraper (2).

2. Device for removing hot-melt adhesive according to claim 1, wherein the scraper has a base element (7), wherein the scraper (2) is arranged starting from the base element (7).

3. Device for removing hot-melt adhesive according to claim 1 or 2, wherein the opening (6) extends over the entire length of the scraper (2).

4. Device for removing hot-melt adhesive according to any of the preceding claims, wherein the baffle plate (3) is arranged in such a way that the angle of contact (α) between the roller (1) and the baffle plate (3) for removing the hot-melt adhesive to the inner side of the scraper (2) is an acute angle, preferably of less than 75°, particularly preferably of less than 50°, even more preferably of less than 30°.

5. Device for removing hot-melt adhesive according to any of the preceding claims, wherein the device is designed such that the hot-melt adhesive can be conveyed away on account of the dynamic pressure, preferably counter to the force of gravity in the vertical direction.

6. Device for removing hot-melt adhesive according to any of the preceding claims, wherein the drain (4) is connected to a heat-resistant drip tray (5).

7. Device for removing hot-melt adhesive according to any of the preceding claims, wherein at least the surface of the baffle plate (3) and / or the inner circumferential side of the scraper (2) has an adhesion-reducing material.

8. Roller application system for applying hot-melt adhesive to a workpiece which consists preferably at least in portions of wood, wood-based materials, plastic material or the like, comprising a device for removing hot-melt adhesive according to any of the preceding claims, and comprising a roller (1) for applying hot-melt adhesive.

9. Roller application system claim 8, wherein the scraper (2) extends over at least the entire length of the roller (1).

10. Edge-banding machine, having: a roller application system according to claim 8 or 9, and an edge-feeding apparatus which is designed such that plastics or wooden edges can be fed at a speed identical to a workpiece-conveying speed to a workpiece which consists preferably at least in portions of wood, wood-based materials, plastic material or the like.