EP2832509B1 - Activation module for a coating device with coating device - Google Patents

Description

The invention relates to an activation module with a device for coating a surface region of a workpiece, according to the preamble of claim 1. Such an activation module is known from the document FR2318736A1 known.

Electric heaters for heating air flowing through, such as. GB 1915 12694 A . FR 2 218 537 A1 and US 2004 252 694 A1 show, the state of the art. Out US 4 222 812 A an activation module according to the preamble of claim 1 is known.

Especially in the furniture industry find plates made of solid wood and wood-based materials use. The latter are usually made of glued and compressed wood chips. Many of these wood-based panels are already provided ex works with a coating, which is regularly limited to the upper and lower sides. At least the remaining in the later field of view narrow sides of the plates therefore require their subsequent coating.

Suitable coatings consist in particular of plastics, which are also known as edge bands and strips. The connection between plate and coating is usually cohesive. For this purpose, a suitable adhesive just before the attachment of the coating on selbiger and / or on the coated Surface area of the plate are applied. These are usually hot melt adhesives. In contrast, some coatings already have an initially inactive and activatable only by heating additional layer of hot melt adhesive.

The presence of hot melt adhesive is disadvantageous in that it sometimes appears visually unattractive in the edge region of the plates. In this context, coating materials have already been developed, which allow the formation of a so-called "zero joint". The materials used in this case do not require an additional adhesive layer, since they either consist of a thermoplastic or have at least one polymeric functional layer. Consequently, the material is adapted to be fused at least on the side of its functional layer. By pressing the thus-fused coating to the plate to be coated, a multiplicity of microfine closures is produced which interlock the coating with the plate after the material has cooled. Since said functional layer is visually equivalent to the rest of the coating, a significantly improved overall aesthetic impression of the thus coated plate is achieved.

For example, a laser can be used for the melting of the functional layer, which laser is directed to its functional layer shortly before the coating material is pressed on. In connection with the coating of the narrow sides of plates, coating materials to be melted in this way are therefore also familiar under the term "laser edge bands". For some It is known that such coating materials can also be melted with hot air.

So is with the DE 10 2011 015 898 A1 a device for coating the narrow sides of a workpiece with such adhesive-free heat-activatable coating material in the form of an edge strip has become known. For this purpose, in addition to a feed device for the edge strip and a pressing device for pressing the heat-activated edge strip to the narrow side of the workpiece further comprises a heating device is provided. The heating device serves to bring the hot air required for activating the edge strip to the required activation temperature. Preferably, the air to be heated is already injected under pressure into the heating device. Subsequently, the hot air heated therein passes through a channel from which it is inflated via at least one outlet slot to a region of the edge strip to be activated. The pressure of the exiting hot air is above atmospheric pressure. By the thus accelerated hot air, a sufficiently rapid transport and a rapid transfer of heat energy to the coating material is to be achieved. In order to heat the required hot air, corresponding heating elements of tube bundles or sintered plates may be arranged within the heating device, the generated heat of which is given off to the air flowing around it. In order to keep the occurring heat losses as low as possible, the heating device is thermally insulated from the environment.

With the device thus indicated, it is possible to partially melt edge strip provided with a corresponding structure shortly before it is attached to the respective workpiece.

From the EP 2 243 619 A1 goes out a device for coating workpieces, which comprises at least two joining devices in addition to a feed and a pressing device. The joining devices are designed to apply an adhesive to a coating material or to activate an already applied adhesive. The arrangement of the at least two joining devices, the probability of failure of the device can be reduced. In addition, so different activation methods can be performed with the same device, for example, in parallel or as needed.

In particular, in series production high cycle times must be achievable with such coating devices in order to enable economic production. Here, the coatings are carried out in particular in continuous operation, with speeds of several meters per second can be achieved.

The use of hot air allows a simpler and thus more favorable compared to laser construction. However, the use of known in the art hot air blowers for melting of coating materials are limited. This is usually due to the fact that the heat energy generated during their transport via the hot air to their place of use rapidly cools despite any insulation measures. Furthermore the heating power of the heating device can not be increased arbitrarily. Nevertheless, in order to transfer the required heat energy in sufficient height to the continuous coating material, its residence time in the region of exposure to the hot air must be increased. However, this also extends the maximum possible cycle times adversely.

Consequently, a particular challenge is to apply sufficient warm hot air to the passing coating material at a suitable location. For example, if the temperature of the hot air does not suffice at the time of its impact on the coating material, it can not provide a durable bond due to insufficient activation. In contrast, if the temperature of the impinging hot air is too high, the coating material may suffer visual disadvantages or even be damaged.

Furthermore, a heating of the material too far ahead of the point of encounter of the workpiece and coating is disadvantageous, as this may not be sufficiently active at the moment of its pressing and therefore also no sufficiently durable connection is feasible. In this connection, mention should be made of the limited available space between the workpiece and the coating material shortly before it is pressed on. Thus, the coating material must be guided at an angle to the surface area to be coated in order to prevent any damage caused by overstretching or even kinking.

Moreover, it would be desirable if the knowledge of the melting of such coating materials by means of hot air would also be applicable by a simple conversion to already existing coating devices. This is particularly true with respect to conventional edge banding machines in which the application of an adhesive takes place shortly before the coating material is pressed against the workpiece.

Against this background, the design of the coating devices in question with hot air and the simple conversion of existing devices on the use of hot air still have room for improvement.

Thus, the object of the present invention is to improve an activation module with a coating device of the type indicated above in such a way that it enables a more efficient heating of coating materials and thus permits higher process speeds. According to the invention, an activation module for heat-activatable materials for coating workpieces is to be presented, with which a simple and efficient retrofitting of existing edge banding machines on the use of hot air is feasible.

The solution of this problem consists according to the invention in an activation module with a coating device having the features of claim 1. Advantageous developments of the basic concept of the invention are the subject of the respective dependent claims.

According to the invention, the activation module described below is suitable with a device for coating a surface region of a workpiece with a coating material that can be activated by a heated gas. For this purpose, the activation module comprises a fan and a heater for heating the gas. According to the invention, a hot gas duct connected in a fluid-conducting manner to the blower is provided, which has an outlet region for the heated gas. Said hot gas duct is adapted to flow directly to the area of the coating material to be activated with the heated gas. According to the invention, the heating device for heating the gas passing through the hot gas channel is arranged within this hot gas channel.

According to the invention, it is provided that the hot gas channel is subdivided into at least two channels. According to the invention, the hot gas channel has a closure means which is adapted to the at least To close two channels either separately or together with respect to the blower.

According to the invention, each of the channels has its own heating device. In this way, the required heating of the gas passing through the respective channel can be regulated. As a result, the coating material can be acted upon at different areas simultaneously with differently heated gas. In any case, the separate heaters are advantageous in that only the channel (s) carrying the gas is actively heated by its heater. In this way the most economical operation of the device is possible.

In addition, no need for cooling of the sometimes not used but still heated heating device or one of their areas by flowing gas is required. This applies in particular to the arrangement of a heating wire, which could otherwise overheat and thus be damaged.

Against the background, in the case of the arrangement of a plurality of heating devices, it is always envisaged that they can be operated either separately from one another or together.

According to the invention, an apparatus for coating a surface area of a workpiece is provided. In the context of the invention, the device for coating is also designated as a coating device, so that the terms used here are to be regarded as synonymous. The to be carried out with the aid of the coating device Coating takes place using a coating material which can be activated by a heated gas. For this purpose, the coating device according to the invention comprises a fan and a heating device and a pressure device.

The heater here serves to heat the gas. The blower is intended to convey and compress the gas. Preferably, the direction of flowing gas from the fan to the heater is such that the heater may be located downstream of the fan.

The gas used is advantageously air, in particular ambient air. Of course, deviating gases or gas mixtures are also conceivable which either enable a better heat transfer and / or promote the activation of the coating material.

The existing pressure device, which in particular has a pressure roller, is designed to press a region of the coating material activated by the heated gas against at least one partial region of the surface region to be coated.

Furthermore, in the region of the pressure device, a hot gas channel connected in a fluid-conducting manner to the fan is arranged. The hot gas channel has at least one outlet region for the heated gas. In this case, the hot gas channel is designed to flow directly to the area of the coating material to be activated with the heated gas.

According to the invention, it is provided that the heating device is arranged within the hot gas channel. In other words, this omits the otherwise customary heating of the gas at a location opposite the coating material and its subsequent transfer.

The resulting advantage lies in the heating of the gas only shortly before its impact on the area of the coating material to be activated. In this connection, it has been recognized that the forwarding of the already heated gas known in the prior art leads to unavoidable heat losses. The present inventive design reduces the known but disadvantageous transmission of the gas after its heating by the heater to a minimum. As a result, the otherwise existing heat losses are completely avoided or largely limited. Consequently, the hot-energy-enriched hot gas strikes the coating material almost immediately after being heated at the approximately maximum temperature.

As a result, the hot gas impinging on the coating material is still so high in energy that the process speed for the application of the coating can advantageously be increased. In addition, the heating occurring only shortly before impacting the coating material results in more efficient heating of the coating material without overheating and possibly damaging it due to heat losses to be observed.

In the heater various embodiments are conceivable, which serve to transfer heat to the gas. Thus, the heater may be such that its heated areas can flow around and / or flow through the gas. It is advantageous to provide a large surface in order to realize as large as possible contact for the transfer of heat energy to the gas within a very short time. Thus, for example, any side walls and / or installations of the heater may be heated, which come into contact with the flowing gas. The heating itself can be done for example via heat-conducting media. The medium may be, for example, a gaseous or liquid fluid, with which the contact areas are exposed to the gas. Preferably, the heater has heating elements, such as e.g. at least one electrically operated heating wire, on. This can be arranged for example as a heating coil within the hot gas channel. The gas flowing past the heating wire cools it in an advantageous manner and at the same time heats the gas to the necessary temperature.

The plurality of heating elements can be operated separately from each other according to the invention, for example by an electrical control or regulation. It can thereby be achieved that over the width of the coating material, the edge band, a predetermined temperature distribution can be adjusted. For example, it may be provided that the edges of the coating are heated more strongly than the middle part.

In the context of an advantageous further development of the concept of the invention, the outlet region for the hot gas be arranged at the end of the hot gas channel. For example, the hot gas duct may have an open end in its extension as the outlet region. Furthermore, this end can also be covered by a wall, through which the outlet region is arranged, for example in the form of at least one opening. It is also conceivable a plurality of openings, which arises for example when using a grid structure as a wall or its perforation through holes or slots.

In this context, it is provided that the heating device extends within the hot gas channel up to its outlet region. This is to ensure that the gas is still heated by the heater until shortly before it exits the outlet region of the hot gas channel. As a result, the path for possible cooling of the gas between the outlet region and the region of the coating material to be heated is advantageously shortened to a minimum.

Depending on the orientation and usable space, the outlet area can of course also be located on a peripheral side of the hot gas channel and thus be arranged laterally. Also in this case, it is provided that the heating device extends at least as far within the hot gas channel that it is also present within the outlet region. In other words, this should ensure that the heating device offers the possibility of heating the gas until shortly before it leaves the outlet region.

In order to allow the most efficient and sufficient heating of the coating material, the heater is thus basically to be arranged before or even into the outlet area inside.

With a view to the design of coating devices of known type, the coating material is guided at an angle to the surface region of the workpiece to be coated. Thus, the coating device according to the invention can be designed such that a flow direction of the hot gas channel and the feed direction of the coating material to the pressure device towards an angle of less than 90 ° between them.

In this context, it is provided that the hot gas duct can have a wedge-shaped end section. By this configuration, this end portion is formed such that its free end extends parallel to the feed direction of the coating material. Particularly preferably, the outlet region of the hot gas channel is arranged in its free end running parallel to the feed direction of the coating material. As a result, the closest possible approach of the hot gas channel, in particular of the outlet region arranged therein, to the coating material is achieved.

In connection with the arrangement of the heating device within the hot gas channel or even its widest possible extent up to the outlet region, the distance of the gas to be covered between its heating and impinging on the coating material is thereby significantly reduced.

In a particularly advantageous development, an exhaust gas shaft corresponding to the hot gas duct may be provided. Corresponding means that exhaust shaft and hot gas channel are in an operative relationship to one another. Particularly preferred in this case are the outlet region of the hot gas channel and the exhaust gas shaft in operative connection. In this case, the exhaust gas shaft is designed to receive and / or absorb the gas flowing out of the hot gas channel and consequently heated gas after it has flowed on the coating material or even in the absence thereof. Particularly preferably, the gas is then correspondingly discharged via a suitable forwarding.

The arrangement of the exhaust shaft advantageously ensures that no heat accumulation can occur in the region of the pressure device. In this way, a highly controlled heating of the respective coating material takes place. Overall, any components arranged in this area are not adversely affected by heat as a result. This unwanted heat application could limit the functioning of these components, increase their wear or even destroy them directly. Furthermore, this also ensures that the coating material is not heated by any deflected gas at areas that are not (yet) to be heated.

As a result of the arrangement of the exhaust gas shaft, it is possible to heat the desired area of the coating material only to a very limited degree and to affect the surrounding areas to a limited extent. In addition, so also a rapid volatilization of the heat energy from the warmed up Prevented gas out, as the heated gas with the least possible ambient air comes into contact by the arrangement of the adjoining the hot gas duct exhaust shaft.

In this context, the exhaust gas shaft can also be arranged to form a feed gap with respect to the hot gas channel. In other words, the exhaust shaft and the hot gas channel can be directly opposite each other. The parts facing each other are preferably the outlet region and an opening of the exhaust gas shaft. In this case, the respective coating material is particularly preferably guided through this feed gap to the pressure device. As a result, in particular, the exchange areas with the ambient air, which are possible for volatilizing the heat energy of the gas, are reduced to a minimum. Thus hot gas duct and exhaust duct can be tightly connected to each other or even formed in one piece.

In order to pressurize the coating material to be heated, for example in web or strip form with the heated gas, only two opposing openings are necessary. The openings may be, for example, slots, which are adapted in width and height to the coating material to be performed.

According to the invention, it is provided that the hot gas channel can be subdivided into at least two or more channels. The subdivision is effected by one or more partitions arranged within the hot gas channel. Of course, the Hot gas duct also be composed of two or more structurally separate channels. In any case, it is provided in this case that the hot gas channel has a closure means which is designed to close the at least two channels either separately or together with respect to the blower.

According to the invention, the respective channels likewise have outlet regions which are separate from one another. Thus, advantageously, the gas conveyed and compressed via the fan can be conducted through one or more channels and accordingly strike the coating material from one or more outlet regions. In this way, a maximum of flexibility is achieved because now also different sizes, in particular different widths coating materials can be processed without any rebuilding measures of the device. For example, the individual channels can be arranged next to or above each other. Accordingly, their respective outlet areas are either side by side or one above the other.

Now, if a narrow material is processed, the width of which can be sufficiently activated with the outlet region of a single channel with heated gas, the or the other channels are correspondingly closed by the closure means. In contrast, wider materials can then also be processed by opening at least one further channel via the closure means. As a result of the simple connection or disconnection of the individual channels via the closure means, coating materials of different sizes can also be used during operation of the device are processed. In this way, the respectively required width of the necessary stream of heated gas via the operation of the closure means is easily adaptable.

The closure means may be, for example, a flap or an arrangement of a plurality of independently operable flaps or linearly movable bulkheads. Of course, said channels of the hot gas duct may also be arranged relative to one another such that the width, but rather the width, of the producible stream of heated gas can be set by their respective connection or disconnection. In this way, also those coating materials can be processed which require a mutually different fastening concept. Specifically, it is conceivable that in this way with one and the same device materials can be processed, which either have a heat-activatable glue layer or else have a corresponding functional layer and consequently are to be melted themselves.

By the above-described design options, a coating device is provided which has a high flexibility with respect to the coating materials to be processed. In particular, the heating which takes place shortly before the gas escapes from the hot gas channel enables extremely efficient heating of the respective coating materials. As a result, for example, in continuous operation they can be guided past the outlet region of the hot gas duct at high speed, and in spite of the high process speed, they can be driven to a sufficient extent by the heat energy of the gas are activated. Overall, the present invention provides a device which exploits the advantages of gas heating of coating materials while overcoming its disadvantages.

Fig. 1

eine Kantenanleimmaschine aus dem Stand der Technik in einer Aufsicht,

Fig. 2

ein Aktivierungsmodul mit einer Beschichtungsvorrichtung nicht gemäß der Erfindung in einer Aufsicht,

Fig. 3

Erfindungsgemäßes Aktivierungsmodul mit einer Beschichtungsvorrichtung

Fig. 4

ein Detail der Beschichtungsvorrichtung aus Fig. 2 in einer Aufsicht in einer alternativen Ausgestaltung sowie

Fig. 5

ein Detail der Beschichtungsvorrichtung aus Fig. 3 in einer Ansicht in einer alternativen Ausgestaltung.

Hereinafter, the present invention will be described with reference to some schematically illustrated in the drawings embodiments. Show it:

Fig. 1

an edge banding machine of the prior art in a plan view,

Fig. 2

an activation module with a coating device not according to the invention in a plan view,

Fig. 3

Activation module according to the invention with a coating device

Fig. 4

a detail of the coating device Fig. 2 in a plan view in an alternative embodiment as well

Fig. 5

a detail of the coating device Fig. 3 in a view in an alternative embodiment.

Fig. 1 shows a known from the prior art apparatus for coating a workpiece in the form of a Kantenanleimmaschine 1. The edge banding machine 1 is adapted to give adhesive to a workpiece 2 and to add a coating material 3 in the form of an edge strip with the workpiece 2.

For this purpose, the workpiece 2 is guided by means of a transport chain 4 parallel to the edge banding machine 1 in a transport direction a. At the same time, a surface region 5 of the workpiece 2 to be coated is wetted with the adhesive. For this purpose, the workpiece 2 is guided past an adhesive indication 6. In this case, the surface region 5 of the workpiece 2 to be coated comes into contact with the adhesive in a manner not shown, as a result of which the adhesive deposits on the workpiece 2.

In order to press the coating material 3 on the wetted with adhesive part of the surface region 5 of the workpiece 2, a pressure device 7 is further provided, which includes in particular a pressure roller 8. Furthermore, the edge banding machine 1 has a separating knife 9 in order to be able to cut the coating material 3 to a corresponding extent. In order to be able to provide further coating material 3a, the edge banding machine 1 also has a magazine 10 which holds a supply of coating material 3a.

From Fig. 1 Outstanding and known in the art Kantenanleimaschine 1 has in the areas of the adhesive 6 and the pressure device 7 each have an installation space 11, 12, which can serve for receiving an activation module according to the invention after removal of the adhesive 6.

The activation module of a coating device described below and resulting from the further figures can be used as an independent coating device 13 or as an edge banding machine 1 retrofitted with the activation module according to the invention Fig. 1 be considered. Consequently, the following statements relate to both possible variants.

Fig. 2 shows a coating device 13, which for coating the surface region 5 of the workpiece 2 not shown here with a activatable by a heated gas 14a coating material third

The coating device 13 has, in addition to the pressure device 7 designed in particular as a pressure roller, the activation module 15 according to the invention, which comprises a fan 16 and at least two heating devices 17, the sectional image only showing one, for heating the gas 14b. As can be seen, a flow direction b of the gas 14 a, 14 b extends from the blower 16 to the coating material 3. Said flow direction b is predetermined by at least two hot gas channels 18, which are arranged in the region of the pressure device 7 and are connected in a correspondingly fluid-conducting manner to the blower 16. According to the invention is the respective Heater 17 disposed within the respective hot gas channel 18. Further, the hot gas passage 18 has a wedge-shaped end portion 19 having an outlet portion 20 for the heated gas 14a.

As a result, the hot gas channel 18 is designed to flow directly to a region 21 of the coating material 3 to be activated with the heated gas 14a.

The coating material 3 to be supplied to the hot gas channel 18 and then to the pressure device 7 has a feed direction c extending parallel to the outlet region 20. In the present case, additional deflection rollers 22 are arranged in front of the pressure device 7, so that the further course of the coating material 3 to be supplied is slightly inclined from its origin from the magazine 10 not shown in detail here relative to the feed direction c.

As can be seen, the flow direction b of the hot gas channel 18 and the feed direction c of the coating material 3 to the pressure device 7 at an angle d of less than 90 ° between them. By the wedge-shaped end portion 19 of the hot gas channel 18 whose free end extends parallel to the feed direction c of the coating material third

Furthermore, the activation module 13 or the coating device 1 comprises an exhaust gas shaft 22 corresponding to the hot gas channel 18. The exhaust gas shaft 22 is funnel-shaped with respect to its junction and thus in front of the outlet region 20 of the hot gas channel 18 arranged so that the exhaust duct 22 can receive the heated gas 14a flowing out of the hot gas duct 18 after the flow of the coating material 3 and can discharge via a line 23. For this purpose, the exhaust gas shaft 22 is arranged to form a feed gap 24 with respect to the hot gas channel 18. In this way, the coating material 3 can be guided through the feed gap 24 to the pressure device 7, wherein it is activated immediately above the heated gas 14a.

Fig. 3 shows a detail of the activation module 15 Fig. 2 or the coating device 13 in a side view. In the present case, a hot gas duct 18 according to the invention is shown. In this partially sectioned illustration it can be seen that the hot gas channel 18 is divided into at least two channels 25, 26. For this purpose, a partition wall 27 is arranged in the interior of the hot gas channel 18, which divides the hot gas channel 18 into a present upper channel 25 and a lower channel 26. Furthermore, a closure means 28 is disposed within the hot gas channel 18. The closure means 28 is arranged between the two channels 25, 26 such that they can be closed either separately from one another or together with respect to the blower 16.

The embodiment of the hot gas duct 18 shown here according to the invention provides that each individual one of the channels 25, 26 of the hot gas duct 18 has its own heating device 17. The present two heaters 17 are operated in a manner not shown in detail either separately or together.

Out Fig. 4 Once again, in an enlarged view, a section of the hot gas channel 18 emerges in a further variant. As can be seen in the present case, the heating device 17 is not arranged centrally but at the end of the hot gas channel 18. As a result, the heating device 17 extends within the hot gas channel 18 as far as its outlet region 20.

Fig. 5 FIG. 12 depicts a view of the outlet region (s) 20 of the hot gas channel 18 Fig. 3 , In both channels 25, 26, the respective heaters 17 are indicated by broken lines. In the presentation of Fig. 5 3 illustrates that the respective outlet regions 20 of the individual channels 25, 26 have individual openings 29 from which the heated gas 14a can flow.

Claims (4)

1. Activation module with a device (13) for coating a surface area (5) of a workpiece (2) with a coating material (3), wherein the coating material (3) can be activated by a heated gas (14a), comprising a fan (16) and a heating unit (17) for heating the gas (14a), as well as a contact pressure device (7) which is configured to press an area (21) of the coating material (3) activated by the heated gas (14a) against at least one partial area of the surface area (5) which is to be coated, wherein a hot gas channel (18) which is in fluid-conveying connection with the fan (16) is provided in the region of the contact pressure device (7), the hot gas channel having an outlet region (20) for the heated gas (14a) and designed to let the heated gas (14a) flow directly to the area (21) of the coating material (3) which is to be activated, wherein the heating unit (17) is arranged in at least some sections inside the hot gas channel (18) and the outlet region (20) is arranged at the end of the hot gas channel (18), wherein the heating unit (17) extends inside the hot gas channel (18) up to its outlet region (20), wherein the hot gas channel (18) is divided into at least two channels (25, 26) by means of a partition wall (27) which is arranged in the hot gas channel (18), characterised in that the hot gas channel (18) has a closure means (28) which is designed to close the at least two channels (25, 26) off from the fan (16) either separately from one another or together with one another, and that each of the channels (25, 26) of the hot gas channel (18) has its own heating unit (17), wherein the at least two heating units (17) are to be operated either separately from one another or together with one another, and each have a plurality of heating elements and the heating elements can be controlled and/or regulated, in particular separately from one another, in order to set a predetermined temperature or temperature distribution.
2. Activation module according to claim 1 characterised by an exhaust shaft (22) which corresponds with the hot gas channel (18) and which is designed to take up and divert the heated gas (14a) flowing out from the hot gas channel (18) after it has flowed past the coating material (3).
3. Activation module according to claim 2, characterised in that the exhaust shaft (22) is arranged through the formation of a supply gap (24) opposite the hot gas channel (18), wherein the coating material (3) can be supplied through the supply gap (24) to the contact pressure device (7).
4. Activation module according to one of the preceding claims, characterised in that a flow direction (b) of the hot gas channel (18) and a supply direction (c) of the coating material (3) to the contact pressure device (7) include an angle (d) of less than 90□ between them, wherein the hot gas channel (18) has a wedged end portion (19) which is designed so that its free end runs parallel to the supply direction (c) of the coating material (3).

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