EP2498919B1 - Application device for applying and irradiating a coating agent that can be cured by radiation - Google Patents

Description

The invention relates to an apparatus and a method for applying a radiation-curable coating composition to a surface to be coated. Furthermore, the invention relates to associated coating agent application components.

In recent times, increasing importance is being attached to lacquers which can be cured by means of UV radiators in exposure chambers. From the DE 10 2007 012 897 A1 For example, an exposure space is known which can irradiate painted components with a plurality of UV lamps. The exposure room includes a floor, a ceiling, two side walls, a front wall and a back wall, all of which are provided with multiple UV emitters. By means of a conveyor to be exposed objects are transported into the exposure room, to then be exposed from the floor, the ceiling, the two side walls, the front wall and the rear wall.

A disadvantage of the exposure space is in particular that certain areas to be irradiated can not be optimally irradiated by means of the radiators. This is particularly problematic for geometrically complex objects, such as motor vehicle body components, the undercuts, depressions, curved sections, cavities, etc., which by means of the above-described exposure space often can not be sufficiently accurately irradiated. So it may be that certain areas too strong, others in turn are under-irradiated, which can lead to a reduced surface quality. A further disadvantage is that separate application and irradiation components as well as separate paint application and exposure chambers are required from each other. Furthermore, two separate steps are required, namely the application of paint and subsequent curing by means of UV lamps. This is associated with a relatively high time, energy and cost.

EP 1 002 587 A2 discloses the production of cured lacquer layers using, for example, a paint robot for the automotive industry with an electrostatic rotary atomizer, wherein the paint is irradiated within the atomizer just before the nozzle for curing with UV light.

EP 1074307 A2 discloses a method for applying a UV curable liquid or pasty plastic strand to a substrate, for example for sealing bead seams on sheet metal parts in the automotive industry. To harden the plastic material, an optical waveguide with its light exit point can open into its flow path within a nozzle head, so that the material is activated before it exits the application nozzle.

Further disclosed DE 60 2004 001 336 T2 a spray gun for applying an actinic radiation curable coating with a spray nozzle and positioned outside the spray gun outputs for actinic radiation, for example in the form of a UV LED array, with the coating material is irradiated after exiting the spray nozzle.

The documents JP 06065523 A and DE 94 19 641 U1 describe further technological background concerning the invention.

The object of the invention is to provide an improved application device and an improved method for applying a radiation-curable coating agent to a surface to be coated. In particular, it should be possible, even with complex objects to ensure a sufficiently accurate irradiation without over- and / or under-irradiated areas. In addition, the irradiation of the coating composition should be effective, homogeneous and / or uniform. Furthermore, the time and cost for the application and curing of the coating composition should be reduced.

These and other objects are achieved with the features of the independent claims.

The invention encompasses the general technical teaching of a radiation-curable coating composition prior to impact To apply radiation to a surface to be coated in order to achieve an effective, homogeneous and / or uniform curing of the coating composition.

The application device according to the invention for applying a radiation-curable coating composition to a surface to be coated is characterized in particular by an application unit for dispensing the coating agent and at least one radiation delivery section for emitting radiation, wherein the at least one radiation delivery section is configured and arranged such that the coating agent projects Impact on the surface to be coated with the radiation comes into contact. There may be a single or a plurality of radiation delivery sections.

As coating materials, preferably lacquers are used. The radiation used may comprise actinic radiation (photocatalytic radiation), corpuscular radiation (e.g., electron beam curing), wave radiation, radioactive radiation, ultraviolet radiation and other suitable radiation. As radiation sources for generating radiation, for example, gas discharge lamps, photodiodes, ultraviolet light emitting diodes and other commercially available radiation sources may be used, e.g. Mercury vapor high / medium pressure emitters, metal halide emitters, cross silver vapor top / low pressure lamps, microwave excited electrodeless lamps, capillary emitters, etc.

It is particularly advantageous because a better and / or predefinable irradiation and crosslinking of the coating composition can be achieved, in particular for geometrically complex objects, resulting in a better surface quality leads. A further advantage is that the application and irradiation of coating agent can be carried out substantially simultaneously, without the requirement of the spatial separation of application and irradiation spaces or of application and irradiation components.

This technique of irradiating the lacquer before it has reached the substrate is preferably possible in conjunction with lacquer systems which preferably have a delayed cure after irradiation. These include e.g. Lacquer systems based on cationic photoinitiators or photolatent bases. Furthermore, this technique is applicable for radical Fotoinitiation, which usually runs very fast.

Reflective means may be provided to reflect the radiation onto the coating agent and / or to reflect back to the coating agent, resulting in more effective irradiation. The reflector means preferably comprise aluminum.

The at least one radiation delivery section may be provided in the application device, in a metering device for metering the coating agent (for example a gear metering pump, a piston metering device, etc.) in the application unit, preferably in a paint tube of a rotary atomizer, for example a module (eg a mixer) for surface enlargement and / or mixing of the coating agent in the paint tube and / or at another suitable location in the application unit may be provided on the application unit, preferably on or in an end face of a rotary atomizer, which faces a surface to be coated during operation of the rotary atomizer , in particular on a steering gas ring and / or external charging means for external charging the coating agent, on a bell cup for a rotary atomizer, on a distributor disc for a rotary atomizer, on a steering gas ring of a rotary atomizer, in a coating agent line for supplying the coating agent to the application unit, and / or on or in a coating agent line for supplying the coating agent to the application unit.

The structure and function of rotary atomizers, metering devices, external charging agents and mixers are generally known as such in the prior art, so that their structure will not be discussed in detail in the context of this description.

Preferably, the at least one radiation delivery section comprises at least one radiation-transmissive section. A particular advantage of the invention is that the radiation-transmissive section can emit radiation over a large area. It is particularly advantageous because the radiation coupling-in area for introducing radiation into the radiation-transmissive section can be many times smaller than the area for emitting radiation onto the coating agent. The surface for emitting radiation is, for example, but not limited to, the surface of a mixer described below, the inner peripheral surface of a closed-walled portion through which coating agent flows, or the coating agent overflow surface of a bell cup.

It is possible to couple one or more radiation conductors to the at least one radiation delivery section and / or the at least one radiation-transmissive section.

The radiation-transmissive portion may surround a portion to be flowed through by coating means to emit radiation substantially uniformly inward over its preferably closed inner circumference. The radiation-transmissive section is preferably closed-walled in cross-section in order to irradiate through-flowing coating agent over its substantially entire inner circumference. The radiation-transmissive section thus preferably has a closed inner peripheral surface. The advantage of this is that the coating agent can thus be irradiated not only from one or two sides, but around the entire outer circumference of the coating agent. This enables effective, homogeneous and / or uniform irradiation of the coating composition.

Preferably, the radiation transmissive portion is a substantially tubular portion, annular portion, or any other closed-walled portion provided to uniformly emit radiation preferably radially inwardly over substantially its entire inner circumference.

In a preferred embodiment, the radiation-transmissive portion comprises a radiopaque outer region and a radiation-transmissive inner region. The radiopaque outer portion and the radiopaque inner portion are preferably provided on the tubular portion so that the inner portion may be a radially inner portion and the outer portion may be a radially outer portion.

Preferably, a radiation conductor, such as a light pipe, glass fibers, etc., can be coupled to the radiation-transmissive portion to the radiation-transmissive Supply section with radiation. The radiation-transmissive portion may be provided so that radiation may propagate in its longitudinal direction and circumferential direction. Preferably, the radiation-transmissive inner region is provided to allow transmission of a portion of the radiation inwardly toward the flowing coating agent, whereas the radiopaque outer region may preferentially reflect a portion of the radiation inwardly toward the radiation-transmissive inner region. On the one hand, it is advantageous that the radiation-transmissive section can deliver radiation to the coating medium flowing through it over its substantially entire inner circumference, and, on the other hand, that the radiation-transmissive section can have a sufficiently long extent in the direction of flow of the coating medium to ensure the homogeneity and / or uniformity of the coating Irradiation continues to improve.

Preferably, the at least one radiation-permeable section is provided on or in a color tube in the application unit, for example in a rotary atomizer, but may also be provided in a coating agent line for supplying the coating agent to the application unit. An advantage of positioning in the application unit is the short time and space between irradiation and application of the coating agent.

According to the invention, the at least one radiation delivery section has at least one radiation conductor, such as a light guide, glass fibers, etc., which projects into a section of the application device to be flowed through by coating means, for example into a color tube in the application unit and / or into a coating agent line for supplying the coating agent to the application unit. The advantage of this is that the coating composition can be irradiated not only from the outside but also from within a portion to be flowed through by coating.

Preferably, at least two radiation conductors are provided which protrude differently far into the section to be flowed through by the coating agent. Thus, the effectiveness, the homogeneity and / or the uniformity of the irradiation can be further improved. The radiation conductors can project into the section through which the coating agent flows so that they are distributed essentially uniformly over the flow cross section of the coating agent.

Alternatively, the application device according to the invention comprises a mixer as a module for surface enlargement and / or mixing of the coating agent, which is arranged in a portion of the application device to be flowed through by coating agent, preferably in a coating medium line for supplying the coating agent to the application unit and / or in the Application unit, for example in a paint tube of a rotary atomizer.

It is preferred that the module is radiation-transmissive. The module is thus a radiation-transmissive section. The module is designed according to the invention to deliver radiation to the coating agent. It is possible to couple a radiation conductor, such as an optical fiber, glass fibers, etc., to the module to provide the module with radiation so that it can deliver the radiation to passing coating agent. The advantage of this is that the module essentially over its entire surface Can irradiate coating agent, resulting in a particularly effective, homogeneous and / or uniform irradiation.

The module according to the invention is a mixer, in particular a static mixer, preferably a Kenics mixer (for example spiral, vortex or grid system). To accommodate the mixer in confined spaces in the application device, the mixer must be correspondingly small in size, and still achieve sufficient mixer results, which conventional mixer are not able. A mixer suitable for the invention could preferably be made by a generative process (for example, rapid prototyping, e.g., laser sintering, laser melting, etc.).

It is possible that a metering device for metering the coating agent is provided. It is also possible that the application unit comprises an atomizer, preferably a rotary atomizer. It is preferred that the atomizer has an end face, which preferably has a steering gas ring and faces the surface to be coated during operation of the application device, a distributor disc, a bell cup, a color tube and / or external charging means.

It is possible to arrange the at least one radiation delivery section and / or the at least one radiation-transmissive section in the metering device, on or in the frontal surface, on the distributor disc, on the bell cup, in or on the color tube, and / or on the external charging means.

A radiation delivery to the coating agent is preferably carried out in the metering device, on or in the front side Surface, through the distributor disc, through the bell cup, preferably the Beschichtungsmittelsüberströmflache, through the paint tube, and / or by the external charging means. Preferably, the front surface, preferably the steering gas ring, the distributor disc, the bell cup, the external charging means, and / or the paint tube made of radiation-transparent material.

It is possible to provide a plurality of radiation emitting sections. The radiation delivery section (s) may be provided on or in the front surface such that the radiation is directed substantially at the bell cup, the radiation is directed substantially directly at a coating agent spray, and / or the radiation is substantially atop one already at coating surface applied coating agent is directed. The radiation delivery section or sections may be arranged immovably on the end face or may be arranged to be movable relative to the application unit. Preferably, the radiation delivery sections are provided in an annular arrangement on the frontal surface. For example, photodiodes, UV light-emitting diodes, etc., or openings, to which radiation is brought by means of radiation conductors, can be positioned distributed around a coating agent outlet opening of the application unit.

An advantage of an irradiation in the region of the distributor disk, the bell cup, above all on the coating agent overflow surface of the bell cup, by the external charging agent, and / or in flight (in the air) of the coating agent is that there the coating agent is present over a large area, so that irradiation is particularly effectively can act on the coating agent to achieve an effective, homogeneous and / or uniform irradiation.

It is possible to form the color tube, preferably of a rotary atomizer, in such a way that radiation is directed from the color tube to the distributor plate and / or radially inward to the coating medium flowing through.

In a further embodiment, the steering gas ring comprises gas nozzles for the delivery of inert gas and / or air. Preferably, the gas nozzles are provided in an annular arrangement on the front surface. The discharged inert gas serves, on the one hand, to prevent unwanted reactions with constituents of the normal atmosphere and, on the other hand, to form the jet of spray emitted by the bell cup. The gas nozzles may be directed to the bell cup or to the spray jet. It is also possible to direct the gas nozzles on a spray edge of the bell cup, which would contribute to atomization of the coating composition. As the inert gas, there may be used, for example, nitrogen, carbon dioxide, water vapor, a rare gas or a polymeric gas which may be provided in an inert gas reservoir.

Further, means for cooling inert gas may be provided to ensure that the inert gas at a lower temperature than the surface to be coated meets the surface to be coated. This leads advantageously to a fogging of the surface to be coated with inert gas.

It is possible to arrange the application unit, the at least one radiation delivery section, and / or the metering device on or in a movable robot arm, preferably at the free end of the mobile robot arm. The advantage of this is that the robot can position the application unit and / or the radiation delivery means exactly and predefined on the surface to be coated or on the surface to be coated, wherein preferably also the radiation dose, the radiation intensity, the radiation angle and other parameters are controllable for which appropriate control units can be provided. This allows an exact, substantially precise and predefined irradiation and / or application of even complex three-dimensional objects, as are common, for example, in motor vehicle body construction. Thus, the risk of over- and under-irradiation with associated surface quality losses can be reduced (eg too intensive irradiation can lead to embrittlement or yellowing by degradation reactions and under-irradiation to a sub-crosslinking). Another advantage of the positioning at the free end of the robot arm is the short distance between the irradiation of the coating agent and the surface to be coated.

For example, the radiation delivery section (s) may be a radiation source for generating radiation, i. "active" generate radiation.

It is also possible for the radiation delivery section or sections to be provided with radiation, preferably by coupling the radiation delivery section (s) to at least one remotely positioned radiation source via at least one radiation conductor or, for example, by the radiation delivery section (s) of a radiation source Radiation source to be illuminated. The radiation is thus generated "actively" from a remotely located radiation source, whereas the one or more Radiation delivery sections Although radiation, but not "active" generate.

It is possible to arrange a radiation source such that its heat output does not adversely affect the coating agent, to provide insulators to thermally separate the radiation unit from the coating agent, to provide means for cooling the radiation source, to position the radiation source so that its heat dissipation occurs the coating agent may act to lower its viscosity or to accelerate its curing reaction, and / or to provide means for heating the coating agent to temper the coating agent to affect its curing reaction.

In one embodiment, the application device may include a paint booth.

The paint booth can be operated in recirculation mode with inert gas or under vacuum.

In one embodiment, the inner walls of the paint booth may be configured as area radiators to further irradiate pre-irradiated coating agent, and / or may further be provided in the paint booth a movable robot having a radiation source to further irradiate pre-irradiated coating agent.

It is possible to provide coated and irradiated surfaces with an anti-stick and / or easy-to-clean coating. It is also possible to provide means to rinse surfaces contacted by coating agents and exposed to radiation with rinse and / or crosslinking-inhibiting components.

As a material for the at least one radiation delivery section, preferably the strählungsdurchlässigen section, the bell cup, the distributor disc, the color tube, the external charging and / or the module, for example, a radiation-conducting or radiation-permeable plastic can be used, such as PLEXIGLAS SUNACTIVE ^® XT or PLEXIGLAS SUNACTIVE ^® GS from Röhm, quartz, quartz glass, special UV-transparent glass, eg quartz glass GE 021Al from Momentive Performance Materials, etc .. Also plastics that are used in the production of the above-mentioned parts by means of stereolithography can be used.

The invention extends the field of application of radiation-curable coating compositions. For example, the invention finds application in pigmented paints as coating agents. Pigmented paints usually have such a high layer thickness on the surface to be coated that adequate irradiation can not be achieved with conventional radiation methods (because of the pigmentation), since the irradiation does not reach to the bottom. Due to the irradiation according to the invention and optional subsequent irradiation, radiation curing can now also be used with pigmented paints.

Advantageously, the crosslinking of two or more layers of paint is possible. Thus, for example, a first basecoat (BC1) and a second basecoat (BC2) can be applied without prior irradiation and the subsequent clearcoat (CC) is irradiated and applied according to the invention. This also requires irradiation of the painted surface. However, it is also possible to irradiate each basecoat layer individually according to the invention.

Advantageously, the invention also allows irradiation of coating agent in one, two or more stages or with a plurality of predefined parameters, such as radiation dose, radiation intensity, radiation angle, etc., whereby specifically different degrees of crosslinking can be generated. For example, a "light" irradiation, preferably in or on the application unit, is usually sufficient for rather lightly loaded surfaces (for example, inner surfaces such as a door entry in a motor vehicle body component). Particularly stressed areas (e.g., exterior surfaces of an automotive body component) may be subjected to further irradiation. It is also possible to use different coating agents for the areas exposed to different levels of stress in order to be able to cope with adequate crosslinking.

Thus, for example, the painting of the interior of a body with a paint system based on latent bases could be done (these are not as high quality as acrylate systems, but require significantly less irradiation) and then cured according to the invention. The subsequent higher-quality outer coating with acrylate systems can be conventional (without irradiation during painting) and can then be cured, for example, with conventional UV lamps. The advantage of this is that the outdoor area, which is more stressed but can also be better achieved with UV lamps, are protected very well with the high-quality acrylate system and the interior area with the latent-base system is sufficiently protected and yet effective (also in poorly accessible areas) can be crosslinked with the application of the invention.

It is furthermore particularly advantageous that, by means of the invention, it is possible to apply and irradiate the coating composition, even in the case of complex three-dimensional surfaces to be coated, without surface quality losses. Since the guidance of the application unit along the surface to be coated, the application and irradiation of the coating agent can be controlled, a particularly high surface quality can be achieved.

Another advantage of the invention is that due to the fact of irradiation of the coating composition before impacting on the surface to be coated, the process time can be reduced.

Also, so-called monocure systems can advantageously be used with the invention. Monocure systems are those that are only (exclusively) cured by radiation. In conventional paint booths, including curing, such monocure systems could not be used satisfactorily on substrates with pronounced "shadow areas" (areas that are not sufficiently accessible with conventional UV lamps). The use of monocure systems requires a particularly effective irradiation, which can be ensured by the invention.

As a further advantage, it should be emphasized that the invention provides a universal applicator for applying and irradiating radiation-curable coating compositions, which can respond to a wide variety of requirements such as radiation dose, radiation intensity, complex objects to be coated, various coating agents, etc., which has hitherto not been possible with conventional application apparatus was.

Further advantages are the low emissions of volatile organic compounds (VOC emissions) and the low energy requirement.

The invention finds particular application in the painting of motor vehicle body components (also module coatings). However, the invention is also applicable to, for example, the rail, aircraft, marine and / or wind energy industries (e.g., rotor blades). However, the invention can also be advantageously used in medical technology (for example germ-resistant UV coatings), in construction (for example facade elements made of polymers with UV coatings), in the field of organic photovoltaics (for example UV-curing individual layers).

It should also be mentioned that the radiation can also be introduced into isolated (high-voltage) atomizers via suitable materials, for example with the aid of radiation and / or light guides, battery operation, potential-separated power supply similar to an electric turbine, etc.

It is possible to combine the coating process, preferably the painting process, with a scrubber or a dry separation to separate the overspray.

In particular, the invention encompasses all radiation-curable coating compositions, preferably paints, as well as all suitable coating methods, preferably coating methods, sometimes also the flooding and the inkjet method.

Furthermore, the invention also includes an associated method for the application device described above.

The method is characterized in particular by the fact that at least one radiation delivery section brings the coating agent into contact with the radiation before impinging on the surface to be coated.

Furthermore, the invention also encompasses associated coating agent application components, in particular rotary atomizer components, preferably a bell cup, a distributor disk, a color tube, external charging means for external charging of the coating agent, a module for increasing the surface area and / or mixing of a coating agent, and / or a metering device. The coating agent application component may be made of radiation-transmissive material or at least have radiation-transmissive material. As a material, for example, a radiation-permeable plastic can be used, such as PLEXIGLAS SUNACTIVE ^® XT or PLEXIGLAS SUNACTIVE ^® GS from Röhm, quartz, quartz glass, special UV-transparent glass, such as quartz glass GE 021A1 of Momentive performance materials, etc .. Also plastics that are at The production of the above-mentioned parts by means of stereolithography can be used.

The radiation delivery section, the at least one radiation-transmissive section, the coating agent application component, the bell cup, the distributor plate, the color tube, sections of the frontal surface, the external charging means, the module, and / or sections of the metering device are in particular radiation-transmissive to actinic radiation (photocatalytic radiation), ultraviolet Radiation, corpuscular radiation (eg electron beam curing), and / or radioactive radiation.

Fig. 1

eine schematische Darstellung eines Längsschnitts eines Strahlungsabgabeabschnitts, der in einer Applikationsvorrichtung gemäß einem ersten Ausführungsbeispiel der Erfindung anzuordnen ist;

Fig. 2

eine schematische Darstellung eines Querschnitts des Strahlungsabgabeabschnitts entlang Linie L1-L1 in Fig. 1;

Fig. 3

eine schematische Darstellung eines in eine Beschichtungsmittelleitung ragenden Strahlungsabgabeabschnitts gemäß einem zweiten Ausführungsbeispiel der Erfindung;

Fig. 4

eine Querschnittsdarstellung eines Teils einer Applikationseinheit, die in einer Applikationsvorrichtung gemäß einem dritten Ausführungsbeispiel der Erfindung anzuordnen ist;

Fig. 5

zeigt eine schematische Darstellung einer Draufsicht auf eine stirnseitige Fläche der Applikationseinheit entlang Linie L2-L2 in Fig. 4;

Fig. 6

eine schematische Darstellung eines Mischers, der in einer Applikationsvorrichtung gemäß einem vierten Ausführungsbeispiel anzuordnen ist;

Fig. 7

eine Querschnittsdarstellung eines Teils einer Applikationseinheit, die in einer Applikationsvorrichtung gemäß einem weiteren Ausführungsbeispiel der Erfindung anzuordnen ist.

Other advantageous developments of the invention are characterized in the subclaims or are explained in more detail below together with the description of the preferred embodiment of the invention with reference to the figures. Show it:

Fig. 1

a schematic representation of a longitudinal section of a radiation delivery section, which is to be arranged in an application device according to a first embodiment of the invention;

Fig. 2

a schematic representation of a cross section of the radiation delivery section along line L1-L1 in Fig. 1 ;

Fig. 3

a schematic representation of a projecting into a coating agent line radiation delivery section according to a second embodiment of the invention;

Fig. 4

a cross-sectional view of a portion of an application unit to be arranged in an application device according to a third embodiment of the invention;

Fig. 5

shows a schematic representation of a plan view of an end face of the application unit along line L2-L2 in Fig. 4 ;

Fig. 6

a schematic representation of a mixer, which is to be arranged in an application device according to a fourth embodiment;

Fig. 7

a cross-sectional view of a portion of an application unit, which is to be arranged in an application device according to a further embodiment of the invention.

Fig. 1 shows a schematic representation of a longitudinal section of a radiation delivery section 10 for emitting radiation S, which is to be arranged in an application device according to a first embodiment of the invention. The radiation delivery section 10 comprises a radiation-transmissive section 11. The radiation delivery section 10 or the radiation-transmissive section 11 is provided substantially tubular or annular and comprises a radiopaque radial outer region 11A and a radiation-transmissive radially inner region 11B.

Further shows Fig. 1 Arrow P1 shows the flow direction of the coating agent B. The section A has an inlet for the coating agent B and an outlet for the coating agent B and is closed in cross-section closed-walled by the radiation-transmissive portion 11, on the one hand to allow flow through the coating agent B and on the other hand to completely enclose the coating agent B in the circumferential direction. In the present embodiment, the portion A is circumferentially bounded by the radiation-transmissive inner portion 11B.

The radiation delivery section 10 can be positioned at any position between a coating agent reservoir and an outlet opening of an application unit, wherein a position close to the outlet opening is to be preferred in order to minimize the distance between the irradiation location and the outlet opening for the coating agent B or the surface to be coated.

A radiation conductor 12, preferably a light guide, is coupled on the one hand to the radiation-transmissive section 11, and on the other hand to a radiation source, preferably a light source. Thus, the radiation delivery section 10, in particular the radiation-transmissive section 11 can be supplied with radiation S in order to deliver it to the coating agent B. The radiation source and the radiation delivery section 10 are thus positioned away from each other.

Fig. 2 shows a schematic representation of a cross section of the radiation delivery section 10 along line L1-L1 in FIG Fig. 1 , There too, the section A, the radiation-transmissive section 11, the radiopaque radial outer region 11A and the radiation-permeable radially inner region 11B, through which the coating agent B flows, can be seen. As in Fig. 2 can be seen, the emission of radiation S takes place over the entire inner circumference of the radiation-permeable radially inner region 11B in the section A to be flowed through by the coating agent B.

Like from the Figs. 1 and 2 is apparent, the radiation-emitting portion 10 and the radiation-transmissive portion 11 is supplied via the radiation conductor 12 with radiation S to irradiate the coating agent B. The supplied Radiation S propagates in the radiation-transmissive portion 11 in its longitudinal direction P2 and its circumferential direction P3 by being partially reflected between the radiopaque radial outer region 11A and the radiation-transmissive radially inner region 11B. In this case, part of the radiation S can escape from the radiation-permeable radially inner region 11B and act on the coating agent B.

The radiation-transmissive portion 11 is designed so that it can emit radiation S over its entire inner peripheral surface and over its entire longitudinal extent. Thus, the through-flowing coating agent B can also be fully irradiated in the circumferential direction, and not only from one or two sides, whereby it is possible to effectively, homogeneously and / or uniformly irradiate the through-flowing coating agent B over the entire flow cross-section.

Another advantage is that a in Fig. 1 shown radiation input surface 13 for introducing the radiation S into the radiation-transmissive portion 11 is many times smaller than the area for emitting the radiation to the coating agent B. That is, in the first embodiment, that the radiation injection surface 13 is many times smaller than the inner peripheral surface of the tubular radiation-transmissive portion 11.

Fig. 3 shows a schematic representation of a protruding into a to be flowed through by coating agent B section A radiation delivery section 20 according to a second embodiment of the invention. Arrow P1 indicates the flow direction of the coating agent B.

The radiation delivery section 20 comprises a radiation conductor 20A, from which four further radiation conductors 20B, 20C, 20D and 20E protrude into the section A. The radiation conductors 20B, 20C, 20D and 20E each have a radiation exit opening at their free end in order to irradiate the coating agent B. Similar to the first embodiment, the radiation delivery section 20 is connected to a radiation source via a radiation conductor 20A.

Radiation conductors 20B, 20C, 20D and 20E protrude at different distances into section A in order to ensure effective, homogeneous and / or uniform irradiation over the flow cross-section of coating agent B. Although, in contrast to the first embodiment, substantially point-like irradiations of the coating agent B take place, due to the arrangement of the radiation conductors 20B, 20C, 20D and 20E in the section A through which coating agent B flows, effective, homogeneous and / or uniform irradiation of the coating agent B can be achieved ,

It is possible for the inner surface of the section to be flowed through by the coating agent B to be provided, at least in regions, with a reflector, e.g. a reflective coating, an aluminum layer, etc. to provide. Thereby, it is possible to reflect the radiation emitted from the radiation conductors 20B, 20C, 20D and 20E, which penetrates the coating agent B, back to the coating agent B, resulting in a more effective irradiation of the coating agent.

Fig. 4 shows a cross-sectional view of a portion of an application unit 35, which is to be arranged in an application device according to a third embodiment of the invention. The application unit 35 is preferably around a rotary atomizer. The rotary atomizer 35 includes a plurality of radiation emitting portions 30, such as a bell cup 30A, a distributor disk 30B, a plurality of radiation means 30D and a paint tube 30C. The radiation means 30D are provided on or in an end surface 31 and directed towards the bell cup 30A (in another embodiment, the radiation means may also be provided so as to be directed directly onto a coating agent spray and / or directly onto the surface to be coated), to provide this with radiation S for delivery to the coating agent B. On the front surface 31, a steering gas ring 32 is further provided with gas nozzles 32A.

In this embodiment, the bell cup 30A and / or the distributor disc 30B are at least partially radiation-permeable.

The color tube 30C is coupled to a radiation source to be supplied with radiation S. The paint tube 30C is directed to the distributor disc 30B to provide it with radiation S for delivery to the coating agent B. The emission of radiation to the coating agent B thus takes place through the bell cup 30A, preferably via the coating medium overflow surface of the bell cup 30A, and through the distributor disk 30B.

The radiation means 30D are arranged in an annular arrangement on the front face 31 around the bell cup 30A. The radiation means 30D are supplied with radiation S via a respective radiation conductor in order to emit the radiation in the direction of the bell cup 30A. The Radiation means 30D and the radiation sources are thus positioned away from each other. This is particularly advantageous when the application unit 35 is to be arranged at the free end of a robot arm, since the weight at the free end of the robot arm can be kept low, which is advantageous for the sensitive robot dynamics. However, it is also possible to arrange the radiation means 30D as radiation sources for generating radiation S directly on the application unit 35, preferably on or in the frontal area 31.

The radiation means 30D are in FIG. 4 directed to the bell cup 30A to irradiate it. Since the bell cup 30A is at least partially radiation-permeable, in particular the coating agent B located on the coating medium overflow surface of the bell cup 30A is irradiated over a large area in order to ensure effective, homogeneous and / or uniform irradiation.

It is also possible to provide the radiation means 30D disposed on or in the end face 31 such that radiation S is directed substantially directly onto a coating agent spray jet, and / or to provide the radiation means 30D arranged on or in the front face 31 such that the Radiation S is directed to a substantially already applied to the surface to be coated coating agent B.

For this purpose, the radiation means 30D should preferably be positioned radially outside the outer edge of the bell cup, as shown schematically in FIG FIG. 4 by the arrow P ', the radiation means 30D' and the radiation S ', in which case the Radius R2 of the radiation means arrangement is greater than the radius R1 of the steering gas nozzle arrangement (see FIG. 5 ).

On the front surface 31 and / or at the free end of a robot arm, the steering gas ring 32 is further provided with the gas nozzles 32A for the release of inert gas G. For this purpose, the application device may comprise an inert gas reservoir. The inert gas G discharged from the steering gas nozzles 32A serves, on the one hand, to form the coating agent B and, on the other hand, to prevent undesired reactions with constituents in the normal atmosphere. The steering gas nozzles 32A are arranged so that the inert gas G is directed to the outer surface of the bell cup 30A and / or the peripheral outer edge of the bell cup 30A.

At the end face 31, further radiation delivery sections can be provided, whose emitted radiation is directed to the coating agent spray and / or to the surface to be coated. Thus, the coating agent B in flight, so between the outer edge of the bell cup 30A and the surface to be coated, are irradiated.

As in particular in Fig. 5 , which is a schematic representation of a plan view of the front surface 31 along line L2-L2 in Fig. 4 can be seen, the Lenkgäsdüsen 32 A and the radiation means 30 D are arranged annularly and concentrically with each other, wherein the radius R 1 of the steering gas nozzle arrangement is greater than the radius R2 of the Strahlungsmittelandordnung. However, an arrangement may be chosen in which the radius R1 is smaller than the radius R2 or the radius R1 is the same size as the radius R2.

The application unit 35 is preferably arranged on or in a free end of a movable robot arm, so that the coating agent B and / or the radiation S can be directed onto the surface to be coated with sufficient accuracy.

In electrostatic coating agent charging (e.g., paint charging), external charging agents are usually used to externally charge the coating agent. The external charging means (external charging fingers) usually have fixing means and electrodes for electrically charging the coating agent. The fastening means usually project finger-like from the end face of an application unit, preferably a rotary atomizer, and are usually arranged at uniform angular intervals around a coating agent outlet opening of the application unit. Preferably, the electrodes are positioned at the free ends of the attachment means to electrically charge the coating agent.

Fig. 6 shows a schematic representation of a radiation delivery section 40, which is to be arranged in an application device according to a fourth embodiment.

The radiation delivery section 40 has a schematically indicated mixer 41 as a module for increasing the surface area and / or mixing of coating agent B, which is arranged in a section A to be flowed through by coating agent B. The mixer 41 is preferably a Kenics mixer, which may for example be arranged in a paint tube of a rotary atomizer. The mixer 41 is made of radiation-permeable material and thus constitutes a radiation-transmissive section. Furthermore, a radiation conductor 42, preferably a light guide, which is coupled on the one hand to the mixer 41 and on the other hand is coupled to a radiation source, preferably a light source. Thus, the mixer 41 can be supplied with radiation to deliver it to the coating agent B.

The mixer 41 is designed so that it can emit radiation over its substantially entire surface. It is advantageous that a radiation coupling surface 43 for introducing radiation into the mixer 41 is many times smaller than the surface for emitting the radiation to the coating agent B. That is, in the fourth embodiment, the light coupling surface 43 is many times smaller than the surface of the mixer 41.

Furthermore, it is advantageous that the irradiation of the coating agent B on the one hand due to the surface enlargement and / or the mixing and on the other hand due to the large-scale release of radiation from the mixer 41 can be extremely effective, homogeneous and / or uniform.

FIG. 7 shows a cross-sectional view of a portion of an application unit 35 ', which is to be arranged in an application device according to a further embodiment of the invention. The application unit 35 'is preferably a rotary atomizer.

In particular shows FIG. 7 a portion of a bell cup 30A '. At least one radiation delivery section 30 'is provided on the bell cup 30A', in particular in the region of the coating medium overflow surface of the bell cup 30A ', in order to apply the radiation S to the coating agent B before it strikes the surface to be coated. The radiation delivery section 30 'may extend substantially throughout the coating agent overflow area. However, the radiation delivery section 30 'can also be provided only in sections at the coating agent overflow surface.

The radiation delivery section (s) 30 'provided in the area of the coating agent overflow area may be provided to self-generate radiation ("active"). It is also possible for the radiation delivery section or sections 30 'to be supplied with radiation by a radiation source positioned remotely in order to apply the coating agent B to it. Preferably, the bell cup 30A 'except for the radiation delivery portions 30' is made of a non-transparent material.

For example, the radiation delivery section 30 'may also be constructed as shown in FIGS FIG. 7 to be seen dashed line on the bell cup 30A 'are provided, so penetrate the bell cup at least in sections.

The invention is not limited to the preferred embodiments described above. Rather, a variety of variants and modifications is possible, which also make use of the inventive idea. However, in the FIGS. 1, 2 . 4, 5 and 7 no application devices or Applizierkomponenten according to claims 1 or 22 shown.

LIST OF REFERENCE NUMBERS

10, 20, 30, 40

Radiation output section

11

Radiation-permeable section

11A

Radiation-impermeable outer area

11B

Radiation-permeable inner area

12, 20A-20E, 42

radiation guide

13, 43

Strahlungseinkopplungsfläche

30A

A bell plate

30B

distribution disc

30C

Farbrohr

30D

radiation means

31

Front surface

32

Steering gas ring

32A

Steering gas nozzles

35

application unit

41

mixer

A

Beschichtungsmitteldurchströmabschnitt

B

coating agents

G

inert gas

S

radiation

R1

Steering gas ring radius

R2

Radiation means radius

P1

Coating flow direction

P2

longitudinal direction

P3

circumferentially

Claims (23)

1. Application device for applying a coating agent (B) which can be cured by radiation (S) onto a surface to be coated, with

   a) an application unit (35) for emitting the coating agent (B); and

   b) at least one radiation emission portion (10; 20; 20A-20E; 30, 30A-30D; 40) for emitting the radiation (S), which is provided such that the coating agent (B) comes into contact with the radiation (S) before hitting the surface to be coated;
   characterized in that

   c) the radiation emission portion (20) comprises at least one radiation conductor (20A-20E; 42) which protrudes into a portion (A) through which coating agent (B) will flow, in order to irradiate the coating agent (B); and/or

   d) the radiation emission portion (40) comprises a mixer (41) for surface area enlargement and/or mixing of the coating agent (B), which is arranged in a portion (A) through which coating agent (B) will flow, in order to emit radiation to the coating agent.
2. Application device according to claim 1, characterized in that the radiation emission portion (10; 20, 20A-20E; 30, 30A-30D; 40) is provided

   a) in the application device; and/or

   b) in a metering device for metering the coating agent (B); and/or

   c) in the application unit (35), preferably in a colour tube (30C) of a rotary atomizer or on the mixer (41) for surface area enlargement and/or mixing of the coating agent (B); and/or

   d) on the application unit (35), preferably on or in an end face (31) of a rotary atomizer, in particular on a shaping gas ring (32) or on external charging means for externally charging the coating agent (B); and/or

   e) on a bell cup (30A) for a rotary atomizer; and/or

   f) on a distributor disk (30B) for a rotary atomizer; and/or

   g) on or in a coating agent line for the supply of coating agent (B) to the application unit (35).
3. Application device according to claim 1 or 2, characterized in that

   a) the radiation emission portion (10; 30, 30A-30D; 40) has at least one radiation-permeable portion (11; 30A-30C; 41); and/or

   b) reflector means are provided to reflect the radiation (S) onto the coating agent (B) and/or back onto the coating agent (B).
4. Application device according to any of the preceding claims, characterized in that a radiation input surface (13; 43) for introducing radiation (S) into the radiation emission portion (10; 40) and/or the radiation-permeable portion (11; 41) is smaller by a multiple than a surface for the emission of radiation (S) onto the coating agent (B).
5. Application device according to claim 3 or 4, characterized in that the radiation-permeable portion (11) surrounds a portion (A) through which coating agent (B) will flow, in order to emit radiation (S) over its inner periphery towards the inside, and/or that the radiation-permeable portion (11) is a substantially tubular and/or annular and/or otherwise closed-wall portion which is provided to emit radiation (S) over its inner periphery towards the inside.
6. Application device according to any of claims 3-5, characterized in that the radiation-permeable portion (11) has a radiation-impermeable outer region (11A) and a radiation-permeable inner region (11A), wherein preferably

   a) a radiation conductor (12) is coupled to the radiation-permeable portion (11) in order to supply this with radiation (S); and/or

   b) the radiation-permeable portion (11) is configured such that radiation (S) can propagate in its longitudinal direction (P1) and peripheral direction (P2); and/or

   c) the radiation-permeable inner region (11B) allows part of the radiation (S) to be transmitted towards the inside; and/or

   d) the radiation-impermeable outer region (11A) allows part of the radiation (S) to be reflected towards the inside to the radiation-permeable inner region (11B).
7. Application device according to any of claims 3-6, characterized in that the radiation-permeable portion is provided

   a) on or in a colour tube in a rotary atomizer or in another application unit; and/or

   b) on or in a coating agent line for the supply of coating agent to the application unit.
8. Application device according to any of the preceding claims, characterized in that at least two radiation conductors (20A-20E) are provided which protrude to different extents into the portion (A) through which coating agent will flow.
9. Application device according to any of the preceding claims, characterized in that

   a) the mixer (41) is radiation-permeable; and/or

   b) at least one radiation conductor (42) is provided which is coupled to the mixer (41) to supply it with radiation (S).
10. Application device according to any of the preceding claims, characterized in that the mixer is a static mixer.
11. Application device according to any of the preceding claims, characterized in that

    a) a metering device is provided for metering the coating agent; and/or

    b) the application unit (35) comprises an atomizer, preferably a rotary atomizer, with

    c) a bell cup (30A); and/or

    d) a distributor disk (30B); and/or

    e) a colour tube (30C); and/or

    f) an end face (31) which preferably has a shaping gas ring (32); and/or

    g) external charging means for externally charging the coating agent (B); and/or
    a radiation emission portion and/or a radiation-permeable portion is arranged

    h) in the metering device; and/or

    i) on the bell cup (30A); and/or

    j) on the distributor disk (30B); and/or

    k) in or on the colour tube (30C); and/or ,

    l) on the end face (31); and/or

    m) on the external charging means; and/or
    a radiation emission can take place onto the coating agent (B)

    n) in the metering device; and/or

    o) through the bell cup (30A), preferably the surface of bell cup (30A) over which coating agent flows; and/or

    p) through the distributor disk (30B); and/or

    q) through the colour tube (30C); and/or

    r) in or on the end face (31); and/or

    s) through the external charging means.
12. Application device according to any of claims 2-11, characterized in that

    a) the bell cup (30A); and/or

    b) the distributor disk (30B); and/or

    c) the colour tube (30C); and/or

    d) the end face (31), preferably the shaping gas ring (32); and/or

    e) the external charging means

    are made of radiation-permeable material.
13. Application device according to claim 11 or 12, characterized in that the radiation emission portion (30) comprises a plurality of radiation means (30D) which

    a) are provided on or in the end face (31) such that radiation (S) is directed substantially onto the bell cup (30A); and/or

    b) are provided on or in the end face (31) such that radiation (S) is directed substantially directly onto a spray jet of coating agent; and/or

    c) are provided on or in the end face (31) such that the radiation (S) is directed substantially onto a coating agent (B) already applied to the surface to be coated; and/or

    d) which are arranged immovably on the end face (31) or arranged movably relative to the rotary atomizer.
14. Application device according to any of claims 2-13, characterized in that the colour tube (30C) is provided to emit radiation (S) onto the distributor disk (30B) and/or radially towards the inside.
15. Application device according to any of the preceding claims, characterized in that means for cooling inert gas are provided in order to guarantee that the inert gas meets the surface to be coated with a lower temperature than the surface to be coated.
16. Application device according to any of the preceding claims, characterized in that

    a) the application unit (35); and/or

    b) the metering device

    are arranged on or in a movable robot arm, preferably on the free end of the movable robot arm.
17. Application device according to any of the preceding claims, characterized in that

    a) the radiation emission portion is a radiation source for generating radiation (S); and/or

    b) the radiation emission portion is provided to be supplied with radiation (S); and/or

    c) the radiation emission portion is provided to be supplied with radiation (S) by being coupled to a radiation source via a radiation conductor; and/or

    d) the radiation emission portion is provided to be supplied with radiation (S) by being irradiated from a remote position, wherein

    e) the radiation source is positioned such that its heat emission does not have a negative effect on the coating agent; and/or

    f) insulators are provided to isolate the radiation source thermally from the coating agent; and/or

    g) means are provided for cooling the radiation source; and/or

    h) the radiation source is positioned such that its heat emission can act on the coating agent in order to lower its viscosity or accelerate its curing reaction; and/or

    i) means are provided for warming the coating agent, for tempering the coating agent so that its curing reaction can be influenced.
18. Application device according to any of the preceding claims, characterized in that a paint booth is provided which can be operated

    a) in circulating air mode with inert gas; or

    b) under vacuum,
    wherein preferably

    c) inner walls of the paint booth are configured as radiators to irradiate the pre-radiated coating agent further; and/or

    d) furthermore, a movable robot is provided in the paint booth which emits radiation to irradiate the pre-radiated coating agent further.
19. Application device according to any of the preceding claims, characterized in that

    a) surfaces touched by the coating agent and exposed to radiation are provided with a non-stick or easy-to-clean coating; and/or

    b) means are provided for flushing surfaces touched by coating agent and exposed to radiation with flushing agent and/or components which inhibit cross-linking effects.
20. Method for applying a coating agent (B) which can be cured by radiation onto a surface to be coated, in particular with an application device according to any of the preceding claims, wherein

    a) an application unit (35) applies the coating agent (B) to the surface to be coated; and

    b) at least one radiation emission portion (10; 20, 20A-20E; 30, 30A-30D; 40) brings the coating agent (B) into contact with the radiation (S) before it hits the surface to be coated;
    characterized in that

    c) at least one radiation emission portion (20, 20A-20E) protrudes into a portion (A) through which coating agent (B) will flow and irradiates the coating agent (B); and/or

    d) a radiation-permeable mixer (41) is supplied with radiation (S) and emits radiation (S) onto the coating agent (B).
21. Method according to claim 20, characterized in that the coating agent (B) flows through a substantially tubular and/or annular and/or otherwise closed-wall radiation-permeable portion (11), and the radiation-permeable portion (11) emits radiation (S) over substantially its entire inner periphery towards the inside onto the coating agent (B), and/or that the radiation (S) is emitted onto the coating agent (B)

    a) in an application device; and/or

    b) in a metering device for metering the coating agent; and/or

    c) in the application unit (35), preferably in and/or by a colour tube (30C) of a rotary atomizer; and/or

    d) on and/or by a bell cup (30A) for a rotary atomizer, preferably on the surface of the bell cup (30A) over which coating agent flows; and/or

    e) on and/or by a distributor disk (30B) for a rotary atomizer; and/or

    f) on or in an end face (31) of the application unit (35); and/or

    g) on and/or by external charging means; and/or

    h) on or in a coating agent line for supplying the coating agent (B) to the application unit (35).
22. Coating agent application component in an application device according to any of claims 1-20, comprising

    a) a bell cup (30A); and/or

    b) a distributor disk (30B); and/or

    c) a colour tube (30C); and/or

    d) external charging means for externally charging the coating agent (B); and/or

    e) a module (40) for surface area enlargement and/or mixing of a coating agent (B); and/or

    f) a metering device;

    characterized in that
    the coating agent application component is made of radiation-permeable material or at least comprises radiation-permeable material, wherein in the case of a colour tube (30C), this has a portion (A) through which coating agent (B) will flow and into which a radiation conductor (20A-20E) protrudes in order to irradiate the coating agent, and/or this contains a mixer (41) for surface area enlargement and/or mixing of the coating agent (B), which is arranged in a portion (A) through which coating agent (B) will flow, in order to emit radiation to the coating agent (B).
23. Application device and/or method and/or coating agent application component according to any of the preceding claims, characterized in that

    a) the radiation emission portion (10; 20, 20A-20E; 30, 30A- 30D; 40); and/or

    b) the at least one radiation-permeable portion (11); and/or

    c) the coating agent application component; and/or

    d) the bell cup (30A); and/or

    e) the distributor disk (30B); and/or

    f) the colour tube (30C); and/or

    g) portions of the end face (31); and/or

    h) the external charging means; and/or

    i) the module (40); and/or

    j) portions of the metering device;
    is/are radiation-permeable for

    k) actinic radiation; and/or

    l) ultraviolet radiation; and/or

    m) corpuscular radiation; and/or

    n) radioactive radiation.

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