DE102011088230A1 - Method for planar application of coating material on e.g. lightweight building board in furniture industry, involves pressing coating material in workpiece so that adhesive agent enables connection between workpiece and coating material - Google Patents

Abstract

The method involves heating a metering device (20) i.e. rotatable metering roller, and/or a rotatable application roller (10) by induction using an induction coil. A workpiece is moved relative to the application roller. An adhesive agent is shifted into an activated liquid state by application of heat, generated by induction, into the metering device and/or the application roller in an activated state. A coating material is pressed in the workpiece so that the adhesive agent enables a connection between the workpiece and the coating material. An independent claim is also included for a coating apparatus.

Description

Technical area

The present invention relates to a coating apparatus having a rotatable application roller for applying an adhesive or a coating material to a workpiece, and a method for coating workpiece backs, which is preferably used in the field of woodworking industry, for example, furniture and component industry. By way of example, machines for the production of composite or lightweight boards, edge banding machines, laminating machines and the like can be mentioned from this area.

State of the art

From the field of laminating technology is the document DE 198 38 581 A1 known.

This document relates to a device for laminating plate-shaped workpieces, Such devices are used in the furniture industry or in the production of ceiling and wall coverings to substantially plate-shaped workpieces, in particular of wood materials whose visible surface and / or workpiece edges from technical or design reasons in the form of depressions, grooves, grooves, elevations, webs, through holes and the like, with a lining lamination, that is to provide a coating material. A pressing device is provided in the known example with three movable during the Anpressvorgangs pressing elements, namely three rotatable cylindrical laminating rollers which are fixed to a support stationary or stationary and extend at right angles to the flow direction across a support plane.

Each of the laminating rollers is assigned a heating device. In such a heater are each two laterally and above the laminating and this arranged opposite to a common support member radiant heater, which are directed to the elastic roll shell and heat it. The heat output of each radiant heater is individually adjustable and chosen so that the roll shell during operation can be heated to a temperature of 20-200 degrees.

As a further prior art is the EP 1 168 889 A2 which relates to an induction roller device with which, for example, thin films can be produced. The known induction roller device comprises a plurality of induction coils accommodated in an inner cylinder, which are each supplied with electricity via connection wires. In the outer cylinder, a chamber is filled with a two-phase heating medium (gas and liquid). Further, cooling tubes are provided to cool an inner iron core and the induction coils. In addition, this apparatus has a dry air supply pipe that additionally supplies dry air to prevent condensation on the cooled induction heating mechanism.

Furthermore, a gluing unit according to the DE 20 2009 006 794 U1 known, which is used for gluing an edge material on a narrow surface of a plate-shaped workpiece. Such a glue unit has a glue applicator roll, which is used to transfer an adhesive film to an edge material. Before a glue is transferred to the glue applicator roll, the glue has to be processed. The heat can be directly, for. B. by means of a heating cartridge, or indirectly z. B. via a separate hot plate or inductive.

Apart from the patent literature explained above, glue application devices are known in which the glue application rollers are heated by means of electric heating cartridges. Such electric heating cartridges are integrated in a glue applicator roll. In addition, an oil or a thermal oil can be used as the transmission medium. Such a thermal oil provides a uniform heat distribution and gives the glue application roller a certain inertia, so that the glue application roller continues to give off heat, although the electric immersion heater is no longer operated. However, this in turn has the disadvantage that such a machine is essentially suitable only for continuous operation, since a certain amount of time is required for the heating of the glue application roller.

Subject of the invention

The present invention has been carried out to provide a method for applying a coating material to plate-shaped workpieces, as well as a coating device whose reaction time is increased, which operates more energy-efficient and allows dynamic control of the temperatures.

The object of the invention is achieved by the subject matter of claim 1 and the subject of claim 9.

Other possibly combinable with each other, preferred embodiments are given in the dependent claims. Moreover, the present invention relates to the use of an induction coil for heating a roller, which in turn emits the heat generated to an adhesive.

It is the core idea of the present invention to operate the coating device by means of induction and thereby to heat an adhesive film or an adhesive to a specific temperature range.

In a first aspect of the present invention, therefore, an induction coil is provided within a rotatable roller. Another aspect of the present invention is directed to providing an induction coil near an outer circumference of the rotatable roller to externally heat the shell body of this roller. In both directions, however, the heat absorbed by the roller is transferred to an adhesive, which is thereby liquefied or kept in a liquid state. In the liquid state, which is also referred to as the activated state, the adhesive can develop an adhesion-promoting property, and thus bond a coating material to a workpiece. "Liquid" in the context of this application relates to a flowable state, which may be liquid, viscous or pasty.

The method according to the invention is provided for the planar application of a coating material to plate-shaped workpieces. In this case, the "planar" application relates to both a coating of a narrow side and an upper or lower side of a workpiece. The said workpieces are in particular made of wood or wood-like materials. However, it can also be lightweight panels made of at least sections of wood, plastic (such as polystyrene) or aluminum.

The method according to the invention comprises the steps:
Heating a metering device, preferably a rotatable metering roller, and / or a rotatable applicator roller by means of induction, moving a workpiece relative to the rotatable applicator roller, wherein an adhesive agent by introducing the induction-induced heat into the metering device and / or the application roller in an activated, in particular liquid state is added, and pressing the coating material to the workpiece, so that the adhesive makes a connection between the workpiece and the coating material.

The operating temperature is in this case preferably in the range of 100-200 ° C, preferably 110-180 ° C is heated, wherein the metering device, preferably a rotatable metering roller, and / or the rotatable applicator roller is heated to 100-200 ° C. In this temperature range, the adhesives used in the present application area can be added to the said activated state. After the adhesive has cooled, the connection between the workpiece and the coating material is subsequently produced. To achieve a certain temperature of the adhesive, the metering device and / or the rotatable application roller is heated to a temperature which is slightly higher than the temperature of the adhesive to be achieved.

Compared with known systems, the present invention has the advantage that only small heating times and short cooling times are required to heat or cool the adhesive film or the adhesive. Accordingly, the responsiveness of such a system is significantly increased. This in turn leads to a better machine availability, since such a machine can be operated as needed, without having to keep the rotatable induction-heated roller during operating times of a plant during short idle times.

Incidentally, it has been shown that a lower energy input is required for the inductive heating. Also, the heating technology can be handled easier and more targeted. Among other things, a very fine temperature setting and subsequent dynamic control are possible.

According to a preferred embodiment, both the metering device in the form of the rotatable metering roller and the rotatable applicator roller are provided such that in a space between the metering roller and the applicator roller, the adhesive agent can preferably be kept in the activated state, and by rotation of the metering roller and the applicator roller preferably in the opposite direction, an adhesive film is formed on the application roller.

After the workpiece comes approximately or partially in contact with the application roller, the adhesive film can be transferred to the workpiece. Subsequently, it is possible to press the coating material onto the workpiece. However, it will be appreciated that the adhesive film could also be applied to a coating material which in turn is pressed against a workpiece. In another aspect, the adhesive is already provided on the coating material, and is activated by approaching the applicator roll. Subsequently, this previously provided with adhesive coating material can be applied to a workpiece.

In this case, it is provided in particular that an induction coil is provided inside the metering device in the form of the rotatable metering roller and / or the application roller, and preferably a fluid can penetrate or be introduced into the metering roller and / or application roller provided with the induction coil.

In a preferred embodiment of the present invention, the application of the coating material to plate-shaped workpieces takes place in a continuous manner.

In a preferred embodiment of the method according to the invention, at least one temperature detection device, in particular a sensor, is provided outside or inside the metering device and / or the applicator roll, and based on the detection result of the temperature detection device, the heat introduced inductively into the metering device and / or the applicator roller is controlled.

By controlling the temperature of the metering device and / or the applicator roll these can always be kept at a constant temperature. In this way a consistent quality is ensured because the adhesive can be heated in a certain temperature range.

Moreover, it is possible in a variant of the method to adjust the viscosity of the adhesive used specifically with the control of the temperature. This has advantages in particular when the adhesive is applied to a workpiece via the application roller. In this case, by the targeted adjustment of the viscosity of the adhesive and the working speed can be adjusted as needed.

For example, to produce faster, in addition to the increase in the rotational speed of the application roller and the temperature is increased such that always an adhesive film is formed with the desired thickness and consistency on the application roller. The adhesive film is then applied to the workpiece.

Should a slower production be required or even a production standstill must be bridged, the temperature of the adhesive can be reduced and thus the viscosity can be changed. Thus, in the case of a production stoppage, the adhesive could be kept in a state in which it can be quickly returned to operation by increasing the temperature, but there is no formation of an adhesive film on the applicator roll.

The present invention also relates to a coating apparatus having a rotatable application roller for applying an adhesive or a coating material to a plate-shaped workpiece, in particular a workpiece made of at least partially wood, wood-like materials, plastic or aluminum. For example, it may be a lightweight board. Furthermore, the coating device has a metering device, preferably a rotatable metering roller, wherein the coating device further comprises an induction coil, with which heat is induced on the rotatable application roller and / or the metering device for activating an adhesive, wherein the activated adhesive means a connection between the plate-shaped workpiece and the coating material.

In a preferred embodiment of the present invention, both the metering device in the form of the rotatable metering roller and the rotatable applicator roller are provided such that the adhesive can be held in a space between the metering roller and the rotatable applicator roller, and by rotation of the metering roller and the applicator roller preferably in the opposite direction, an adhesive film is formed on the application roller. In this way, an adhesive can be held, and depending on the size of the gap between the metering roller and the application roller, an adhesive film of a certain thickness is continuously formed and transferred to a workpiece.

Preferably, an induction coil is provided within the metering device in the form of the rotatable metering roller and / or the application roller, and the metering roller provided with the induction coil and / or the application roller has an insulation between an outer casing and the induction coil. With the internal induction coil heat can be applied evenly and energy efficiently on the corresponding roller. The insulation protects the induction coil from heat input.

In addition, a flushing channel may be provided, in which a fluid is guided. The term "fluid" as used herein refers to a gas, such as air, or a liquid. The fluid is adapted to receive a heat induced in the metering roller and / or the application roller, and thus to protect the internal induction coil. The waste heat absorbed by the fluid could be used via a heat exchanger to generate energy.

In a preferred embodiment of the present invention, a temperature detection device, in particular a sensor, is provided outside or inside the metering device and / or the application roller such that a temperature in the heated portion of the metering device and / or the applicator roller can be detected.

Specifically, the temperature detection device could be provided in the above-mentioned insulation such that it points in the direction of the jacket of the metering device and / or the applicator roll and, if necessary, is in contact with them.

Furthermore, provision could be made for a plurality of temperature detection devices, for example 3-5 or more temperature detection devices, to be provided along the longitudinal axis of the metering device and / or the applicator roller with which a specific section of the respective roller is monitored. The individual results can preferably be used to control individual sections of the induction coil, which can be designed in several parts, and thus to regulate the temperature of the metering device and / or the applicator roller in sections.

Brief description of the drawings

1 shows a perspective view of an adhesive application device according to a first embodiment of the present invention, which is used in the processing of plate-shaped workpieces.

2 is a detail view of in 1 shown device.

3a is a schematic view of the adhesive application device according to 1 ,

3b Fig. 10 is a schematic view of an adhesive application device according to a second embodiment of the present invention for double-sided adhesive application

Detailed Description of the Preferred Embodiments

Hereinafter, purely by way of example, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, further modifications and fields of application of the presently claimed subject matter are explained.

In particular, the described embodiment is based on an adhesive application device with which a plate-shaped workpiece can be provided with an adhesive surface.

By contrast, so-called edge banding machines are used to provide a coating material or a workpiece narrow side with adhesive, and then to press the coating material onto the workpiece narrow side. In the laminating technique, in turn, the workpiece is provided with a coating material which is already provided with an adhesive.

1 shows an adhesive application device according to a first embodiment of the present invention with a frame 1 , the four concrete elements in the concrete embodiment 1a as well as four cross struts 1b having. Furthermore, two side plates are laterally 2 . 3 at the frame 1 attached. The side plates 2 . 3 represent a support for the elements described below.

On one of the side plates 2 is a drive unit 4 provided, which is a drive for an applicator roll 10 , a metering roller 20 and optionally other rollers such as a support roller 50 , or another applicator roll 10 ' or another metering roller 20 ' provides (see also 3a and 3b ). In the described embodiment, the applicator roll 10 and the metering roller 20 through the drive unit 4 operated in reverse.

As 2 can be seen in detail, are between the applicator roll 10 and the metering roller 20 page elements 30 . 31 provided such that between the applicator roll 10 , the metering roller 20 and the page elements 30 . 31 a "basin" is formed. In this space, a rod-shaped adhesive element can be inserted and liquefied as described below.

The metering roller 20 that over two on the frame 1 mounted bearings 26 . 27 is supported, has a metal shell 21 (For example, steel jacket) and insulation 22 on. The insulation 22 can the inside of the metering roller 20 in front of a metal shell 21 protect developed heat. Furthermore, within the metering roller 20 a flushing channel 23 provided, via which a cooling medium, such as air, in the metering roller 20 can be introduced.

Inside the flushing channel 23 is an induction coil 27 provided by an inner cylinder 28 inside the metering roller 20 is held. The inner cylinder 28 points inside a supply channel 24 in which, for example, data lines and / or the supply lines of the induction coil 25 be guided. The data lines or supply lines are in 2 not shown in detail. In operation, the supply channel 24 in addition to the already mentioned cooling medium, such as air, are acted upon, which has a side opening having inner cylinder 28 is introduced.

In the described embodiment, an applicator roll 10 and a metering roller 20 intended. The applicator roll 10 this has no own heating device, as with the metering roller 20 is described.

In another embodiment, the applicator roll 10 but similar to the metering roller 20 be formed, and in particular have an induction coil in the interior.

Furthermore, it is possible in the 1 and 2 To operate device shown with only one roller. In this case, the melt is applied directly to an inductively heated applicator roll, and transferred from this to a workpiece.

In 3a FIG. 12 is a schematic side view of an adhesive applicator according to a first embodiment of the present invention, which forms a variant of a coating apparatus in which an adhesive is transferred to a workpiece (or alternatively to a coating material). The adhesive applicator here already has the 1 and 2 described applicator roll 10 and the metering roller 20 on. Below these two rollers is the rotatable support roller 50 provided such that between the applicator roll 10 or the metering roller 20 and the back-up roll 50 a conveying gap is formed, can pass through a workpiece W.

In the 3a shown adhesive application device is adapted to apply an adhesive film L1 on one side of the workpiece W areally. Accordingly, after being passed through the adhesive application device, the workpiece W is wetted with an adhesive film L1 in such a way that it can produce a bond between the workpiece W and a coating material (not shown) which is planarly applied thereto.

The adhesive application device according to Embodiment 1 has a feeder 40 on, which in turn supports 41 as well as roles 42 includes. At least some of these roles 42 can be driven to a workpiece W the rollers 10 . 20 . 50 supply.

Furthermore, another conveyor 43 provided, which also supports 45 and roles 44 having. With the further conveyor is a workpiece from the range of rollers 10 . 20 . 50 removed and optionally fed to a further processing.

3b shows a second embodiment of an adhesive application device according to the present invention. This differs from the in 3a shown embodiment, that instead of the lower support roller 50 another applicator roll 10 ' and another metering roller 20 ' are provided. By providing the additional applicator roll 10 ' and the other metering roller 20 ' For example, it is possible to apply an adhesive film L2 flat on another side of a workpiece W. The further application roller 10 ' and the other metering roller 20 ' are essentially similar in structure to the applicator roll 10 and the metering roller 20 in 2 ,

Since a workpiece according to the second embodiment is provided on both sides each with an adhesive film L1, L2, the further conveying device 43 ' arranged to apply a coating material on the side of the workpiece W, that of the other applicator roll 10 ' and the other metering roller 20 ' is facing.

The operation of the in the 1 and 2 The device shown is as follows. The applicator roll 10 as well as the metering roller 20 are in by the side elements 30 . 31 trained room with an adhesive. This can be done before the start of operation of the adhesive application device, or continuously. In advance or parallel to this, the metal shell 21 the metering roller 20 through the induction coil 23 heated. As a result, the adhesive, which is usually solid at room temperature (for example granules), changes to a liquid state.

The applicator roll 10 and the metering roller 20 are rotated in opposition to each other. This passes through the between the applicator roll 10 and the metering roller 20 formed gap an adhesive film on the applicator roll 10 ,

A workpiece W is in the in 1 indicated passage direction below the metering roller 20 and the applicator roll 10 guided, and thereby the adhesive film D1 transferred to the plate-shaped workpiece. In a further, not shown in detail process step, a coating material is then pressed onto the plate-shaped workpiece, and connected via the adhesive film to the workpiece.

It can be seen here that the adhesive film formed on the workpiece in the described embodiment can also be applied to the coating material.

Furthermore, in the 1 and 2 a device is shown, which is provided primarily for coating the flat portions of plate-shaped workpieces. However, the present invention is also applicable to such devices adapted for coating edges of plate-shaped workpieces.

In a further, not explicitly illustrated variant of the present embodiment, the metering roller 20 not through one in the metering roller 20 heated induction coil. Rather, in an environment of the metering roller 20 an induction coil provided with the metal shell of the metering roller 20 can be heated. By way of example, this induction coil could be used in the in 1 shown device side of the metering roller 20 be provided. It is in one Another variant possible that such an induction coil at the same time the applicator roll 10 and the metering roller 20 heated.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19838581 A1 [0002]
• EP 1168889 A2 [0005]
• DE 202009006794 U1 [0006]

Claims (15)

Method for the surface application of a coating material to plate-shaped workpieces, in particular workpieces made of wood, wood-like materials, plastic or aluminum, which method comprises the steps of: - heating a metering device ( 20 ), preferably a rotatable metering roller ( 20 ), and / or a rotatable applicator roll ( 10 ) by induction, - moving a workpiece (W) relative to the rotatable application roller ( 10 ), wherein an adhesive (L1, L2) is introduced into the metering device by introduction of the induction-induced heat ( 20 ) and / or the application roller ( 10 ) is placed in an activated, in particular liquid state, and - pressing the coating material to the workpiece, so that the adhesive produces a connection between the workpiece and the coating material. A method according to claim 1, wherein the adhesive is at least partially heated to an operating temperature of 100 - 200 ° C, preferably 110-180 ° C, wherein the metering device ( 20 ), preferably a rotatable metering roller ( 20 ), and / or the rotatable applicator roll ( 10 ) is heated to 100-200 ° C. Method according to one of the preceding claims, wherein the coating material is applied to a broad side or a narrow side of a workpiece. A method according to claim 1 or 2, wherein the adhesive on an already provided with the adhesive coating material by the inductively heated applicator roll ( 10 ) is activated. Method according to one of the preceding claims, in which both the metering device ( 20 ) in the form of the rotatable metering roller ( 20 ) as well as the rotatable applicator roller ( 10 ) are provided such that in a space between the metering roller ( 20 ) and the application roller ( 10 ) the adhesive may preferably be kept in the activated state, and by a rotation of the metering roller ( 20 ) and the application roller ( 10 ) preferably in the opposite direction an adhesive film (L1, L2) on the application roller ( 10 ) is formed. Method according to Claim 5, in which an induction coil ( 25 ) within the metering device ( 20 ) in the form of the rotatable metering roller ( 20 ) and / or the application roller ( 10 ), and preferably a fluid into which the induction coil ( 25 ) provided metering roller ( 20 ) and / or in the application roller ( 10 ) can penetrate or is introduced. Method according to one of the preceding claims, in which the application of the coating material to plate-shaped workpieces (W) is carried out in a continuous process. Method according to one of the preceding claims, wherein at least one temperature detection device, in particular a sensor, outside or inside the metering device ( 10 ) and / or the applicator roll ( 20 ), and on the basis of the detection result of the temperature detection device inductively in the metering device ( 10 ) and / or the applicator roll ( 20 ) introduced heat is controlled. Coating device with a rotatable application roller ( 10 ) for applying an adhesive or a coating material to a plate-shaped workpiece, in particular a workpiece made of at least partially wood, a wood-like material, plastic or aluminum, and a metering device ( 20 ), preferably a rotatable metering roller ( 20 ), which coating device further comprises an induction coil ( 25 ), with the heat at the rotatable applicator roll ( 10 ) and / or the metering device ( 20 ) is induced to activate an adhesive, wherein the activated adhesive provides a bond between the plate-shaped workpiece and the coating material. Coating device according to Claim 9, in which both the metering device ( 20 ) in the form of the rotatable metering roller ( 20 ) as well as the rotatable applicator roller ( 10 ) are provided such that in a space between the metering roller ( 20 ) and the rotatable applicator roll ( 10 ) the adhesive can be kept, and by a rotation of the metering roller ( 20 ) and the application roller ( 10 ) preferably in the opposite direction an adhesive film (L1, L2) on the application roller ( 10 ) is formed. Coating device according to Claim 9 or 10, in which an induction coil ( 25 ) within the metering device ( 20 ) in the form of the rotatable metering roller ( 20 ) and / or the application roller ( 10 ), and preferably with the induction coil ( 25 ) provided metering roller ( 20 ) and / or the application roller ( 10 ) between an outer jacket ( 21 ) and the induction coil ( 25 ) an insulation ( 22 ) having. Coating device according to claim 11, wherein between the insulation ( 22 ) and the induction coil ( 25 ) a flushing channel ( 23 ) is provided, through which a fluid can be passed. Coating device according to Claim 11 or 12, in which the induction coil ( 25 ) by one within the metering roller ( 20 ) and / or the Application roller ( 10 ) received inner cylinder ( 28 ), which is relative to the metering roller ( 20 ) and / or the application roller ( 10 ) is provided fixed and a jacket of the metering roller ( 20 ) and / or the application roller ( 10 ) rotatably supports. Coating device according to one of claims 11-13, wherein within the induction coil ( 25 ) a supply channel ( 24 ), in which supply channel ( 24 ) a data line and / or a power cable for the induction coil ( 25 ) is recorded. Coating device according to one of claims 9-14, wherein a temperature detection device, in particular a sensor, outside or inside the metering device ( 10 ) and / or the applicator roll ( 20 ) is provided such that a temperature in the heated portion of the metering device ( 10 ) and / or the applicator roll ( 20 ) can be detected.

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