EP0050269B1 - Process and device for varnishing hollow cylindrical bodies all-around, such as can-bodies - Google Patents

Process and device for varnishing hollow cylindrical bodies all-around, such as can-bodies Download PDF

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Publication number
EP0050269B1
EP0050269B1 EP81108013A EP81108013A EP0050269B1 EP 0050269 B1 EP0050269 B1 EP 0050269B1 EP 81108013 A EP81108013 A EP 81108013A EP 81108013 A EP81108013 A EP 81108013A EP 0050269 B1 EP0050269 B1 EP 0050269B1
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EP
European Patent Office
Prior art keywords
driven
mandrels
coating roller
roller
hollow body
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP81108013A
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German (de)
French (fr)
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EP0050269A1 (en
Inventor
Hans-Juergen Schlinsog
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ardagh Metal Packaging Germany GmbH
Original Assignee
Schmalback Lubeca AG
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Publication date
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Publication of EP0050269A1 publication Critical patent/EP0050269A1/en
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Publication of EP0050269B1 publication Critical patent/EP0050269B1/en
Expired legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00—Processes for applying liquids or other fluent materials
    • B05D1/28—Processes for applying liquids or other fluent materials performed by transfer from the surfaces of elements carrying the liquid or other fluent material, e.g. brushes, pads, rollers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C1/00—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating
    • B05C1/02—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating for applying liquid or other fluent material to separate articles
    • B05C1/022—Apparatus in which liquid or other fluent material is applied to the surface of the work by contact with a member carrying the liquid or other fluent material, e.g. a porous member loaded with a liquid to be applied as a coating for applying liquid or other fluent material to separate articles to the outer surface of hollow articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C13/00—Means for manipulating or holding work, e.g. for separate articles
    • B05C13/02—Means for manipulating or holding work, e.g. for separate articles for particular articles
    • B05C13/025—Means for manipulating or holding work, e.g. for separate articles for particular articles relatively small cylindrical objects, e.g. cans, bottles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C9/00—Apparatus or plant for applying liquid or other fluent material to surfaces by means not covered by any preceding group, or in which the means of applying the liquid or other fluent material is not important
    • B05C9/08—Apparatus or plant for applying liquid or other fluent material to surfaces by means not covered by any preceding group, or in which the means of applying the liquid or other fluent material is not important for applying liquid or other fluent material and performing an auxiliary operation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00—Processes for applying liquids or other fluent materials
    • B05D1/002—Processes for applying liquids or other fluent materials the substrate being rotated
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D2254/00—Tubes
    • B05D2254/02—Applying the material on the exterior of the tube

Definitions

  • the invention relates to a method and a device for the all-round painting of cylindrical hollow bodies, such as can hulls, in which the hollow bodies are held on thorns of a driven thorn wheel that can be driven about their longitudinal axis, pressed against a driven painting roller of a coating unit running axially parallel to the thorn wheel, and in the area of contact with the painting roller with the thorns are guided along the contour of the roller.
  • the all-round painting of cylindrical hollow bodies takes place according to the aforementioned known method in such a way that the hollow bodies held on the drivable mandrels of a rotatingly driven thorn wheel are set in a rotational movement with the thorns, so that the peripheral speed of the hollow bodies in the region of Contact with the coating roller is the same as the peripheral speed of the coating roller, so that the hollow body and the coating roller roll on one another and under the action of the pressure between the hollow body and the coating roller, a coating transfer from the roller to the hollow body takes place.
  • contact is maintained over the duration of two revolutions of the hollow body with the painting roller plus a short overlap area.
  • the paint supplied by the painting roller is squeezed, so that a paint jam or build-up of paint forms in the feed gap between the respectively approaching areas of the hollow body and the painting roller, which builds up over the entire contact time between the hollow body and the painting roller is preserved.
  • a coating split i.e. a longitudinal separation of the paint film located between the hollow body and the surface of the painting roller, with no uniform tearing off.
  • the degree of the lacquer structure on the hollow body depends to a large extent on the viscosity of the lacquer and also on the peripheral speed of the hollow body and the coating roller.
  • the drivable mandrels of the thorn wheel with the hollow bodies held thereon are driven only over a short section of their movement path in the direction of the painting roller.
  • the mandrels are no longer driven, but the synchronous peripheral speed of the painting roller and the hollow bodies is approximately maintained by the pressure of the roller against the hollow bodies.
  • the circumferential speed of the hollow body and the coating roller is about 2 m / sec in the previously known all-round coating. and can be up to 6 m / sec. be increased.
  • the paint is atomized during the separation of the described individual bridges formed from the paint, so that a paint mist is formed which must be avoided under all circumstances to avoid malfunctions in the devices for carrying out the all-round painting and also to avoid environmental pollution.
  • the object of the invention is to achieve an improvement in the paint application by uniformizing the paint coating on the hollow body, so that a reduction in the paint requirement while maintaining the optically perceptible covering quality or with the same amount of paint as before, an improvement in the covering quality can be achieved.
  • the use of highly viscous paints with little solvent content should also be made possible at economically justifiable peripheral speeds.
  • the method mentioned at the outset is characterized in that the hollow body and the coating roller are separated with different peripheral speeds between at least 2 and a maximum of 6 m / sec. and the hollow bodies are driven at a peripheral speed which is 10 to 80% higher in relation to the peripheral speed of the coating roller during pressure contact with the coating roller, the hollow bodies being driven at a higher peripheral differential speed at the beginning and at the end of pressure contact with the coating roller in the middle of the touch.
  • the noticeably higher peripheral speed of the hollow body compared to the coating roller is not comparable in its size and also in its effect with the possible differential speed between a printing medium and the hollow body to compensate for the desired and actual circumference of the hollow body according to the known method. It effects a hydrodynamic application of the paint film on the hollow body.
  • the lacquer layer acts like a lubricant and, due to the higher peripheral speed of the hollow body compared to the lacquer roller, is drawn into the feed gap to such an extent that there is no lacquer build-up in this gap.
  • the paint is no longer separated as in the case of synchronized roller painting in such a way that the interacting surfaces of the hollow body and the painting roller are lifted off exclusively with the formation of bridges and threads during the paint splitting, but rather due to the higher peripheral speed of the hollow body, the paint film is more or less sheared off in the area of the hollow body radius.
  • the overlap area of the order the accumulation of the paint that would otherwise remain there when the hollow body is lifted from the painting roller is avoided, and at the same time the structure created by the paint splitting and the paint tear-off with the thread formation is not formed, so that a calmed and even paint film is applied to the hollow body.
  • the lacquer tear is oriented towards the surface of the hollow body without any notable thread formation, so that the lacquer gap angle, i.e. the angle between the separating lacquer bridges in the pull-out gap is reduced with increasing speed of difference of the hollow body compared to the painting roller.
  • the all-round painting of the hollow body can take place over a smaller peripheral area of the painting roller compared to the synchronous painting, so that the peripheral area of the painting roller interacting with the mandrel wheel can be shortened compared to the known design and thus a shorter deflection distance of the mandrels from the circular path is required.
  • the new process will it is also possible to process water-based paints, which are known to have poor flow properties and are not suitable for synchronous printing painting.
  • the hollow body having a provisions for a wide range of properties of a coating application.
  • the coating roller with a peripheral speed of about 4 to 4.3 m / sec. to drive.
  • the coating roller has shown that at these peripheral speeds it was possible to achieve particularly favorable results with regard to a uniform coating application.
  • the described type of lacquer separation in the new method makes it possible and expedient to design the method in such a way that the lacquer transfer is carried out by roto-gravure offset.
  • This type of paint transfer is possible for the first time through the invention.
  • the rotary gravure offset printing process cannot be used practically in the case of synchronous printing coating, since this results in increased structure formation on the one hand due to the engraving itself and on the other hand during coating splitting, which according to the invention is compensated for by the higher peripheral speed of the hollow body compared to the coating roller.
  • the invention is based on a device with a rotatingly driven coating roller and a rotatingly driven mandrel wheel, the mandrels of which are arranged perpendicular to the wheel plane and can be freely rotated about their longitudinal axis and to adapt their movement path to the peripheral surface of the mandrel projecting into the circular path of the mandrels Paint roller over a part of the wheel circumference by means of control curves in the direction transverse to its longitudinal axis are held on the thorn wheel.
  • this known device is designed such that a controllable on the mandrels in the area before their deflection from the circular path to adapt to the peripheral surface of the coating roller until the beginning of the deflection and again towards the end of the deflection and the rotation of the mandrel about its longitudinal axis Drive device is provided.
  • the drive device consists of an endless belt drive, the drive section of which is stretched between two deflection rollers arranged in the direction of movement of the mandrel wheel in front of and behind the deflection area of the mandrels and on the mandrels in the area before and at the beginning and towards the end of the deflection supports the circular path.
  • This drive device can be designed in a particularly simple manner and can be designed by the arrangement of the deflecting rollers in such a way that the mandrels are released from the drivable strand as a result of their deflection from the circular path after the start of the painting process, but again enter the path of movement of the strand towards the end of the painting process and therefore from the run can be taken again.
  • the mandrels with the hollow bodies located thereon are driven at the beginning and towards the end of pressure contact with the coating roller with a higher circumferential differential speed than in the middle region of the contact.
  • a part of the mandrel wheel 1 is shown purely schematically, which cooperates with a painting roller 2.
  • the spike wheel 1 can be driven about its central axis 1a in the direction of the arrow 1b and is equipped on its circumference with spikes 3, which are arranged at a uniform spacing on the circumference of the spike wheel 1.
  • the mandrels 3 are rotatably mounted in the mandrel wheel 1 and held rotatably about their longitudinal axes.
  • the hollow body 4 to be painted is held against rotation. They are fed to the mandrels 3 in a known manner and pushed onto them and, after the all-round lacquering, removed again and passed on for further processing.
  • the mandrels 3 are held on the mandrel wheel 1 by means of a control device, not shown in the drawing, for adapting to the movement path of the coating roller 2, which is driven to rotate about its central axis 5, in the direction transverse to its longitudinal axis, so that the mandrels 3 are moved out of the circular path of their central axes, designated overall by 6, in the region of the coating roller 2 along the path 6a and remain in contact with the coating roller 2, which is driven to rotate in the direction of the arrow 7.
  • An endless belt drive 9 which rotates in the direction of arrow 8 and is guided around the deflection rollers 10, 11 and 12, of which at least one is simultaneously designed as a drive roller, is used to drive the mandrels 3. It can be seen that the run 9a of the belt drive 9 rests on the mandrels 3 in order to drive them before their deflection and pressure contact with the painting roller 2 about their central axes and to set them in rotation.
  • the mandrels 3 move away from the strand 9a by their guidance along the movement path 6a, so that the driven in this area is interrupted, but before lifting the hollow body from the painting roller 2 come back into contact with the strand 9a, so that they are driven towards the end of the pressure contact with the painting roller.
  • the mandrels 3a and 3b are still or again driven via the run 9a of the belt drive 9, while the mandrel 3c is out of contact with the run 9a, but lies on the peripheral surface of the coating roller 2.
  • the belt drive 9 brings the mandrels 3 to a peripheral speed which is higher than the peripheral speed of the coating roller 2.
  • the peripheral speeds of the coating roller and the mandrels are between 2 and a maximum of 6 m / sec.,
  • the peripheral speed of the mandrels 3 and / or thereon held hollow body 4 during the pressure contact with the painting roller 2 is 10 to 80% higher than the peripheral speed of the painting roller 2. This results in completely different conditions for the paint application from the painting roller 2 to the hollow body 4 than they do in a synchronous operation, that is same peripheral speed of the hollow body and the coating roller occur.
  • FIG. Schematically shows the conditions in a synchronous printing coating.
  • the peripheral surface 2a of the coating roller 2 moves at a speed V 2 in the direction of the arrow 13.
  • the hollow body 4 is also driven or carried along by the coating roller 2 at a speed V, in the direction of the arrow 14.
  • V I V 2
  • the paint application takes place during the pressing position of the hollow body 4 against the painting roller 2 shown in FIG.
  • the lacquer is separated, that is to say the lacquer splitting, approximately along the bisector 21, the entire angle being referred to as the lacquer gap angle.
  • the hollow bodies 4 are brought by the belt drive 9 to a relatively high differential speed with respect to the painting roller 2 until their pressure contact with the painting roller 2, so that only a relatively thin coating film is applied to the surfaces of the hollow bodies 4 at the beginning of the coating application. Because the hollow bodies 4 are lifted from the drive strand 9a after the pressure contact with the painting roller 2 begins, the difference in their peripheral speed compared to the peripheral speed of the painting roller is reduced by the sliding friction, so that the paint application gradually increases until the end of the painting process renewed drive of the associated mandrel 3 by the renewed attack of the belt drive 9 or 9a.
  • the lacquer application 23 shown on an enlarged scale takes place, which serves as a base 231 of the second lacquer application during the second circulation D 2 .
  • This paint application is designated by 24 in FIG.
  • the paint application 24 increases in thickness until the corresponding hollow body is driven again towards the end of the all-round painting. This point in time or this area of the peripheral surface of the hollow body 4 is indicated at 25 in the development of FIG. 4.
  • the thickness of the paint application is reduced again corresponding to the area 26 until the hollow body 4 lifts off. This results in a paint application, as shown in Fig. 4 by the hatched areas.
  • this varnish application has a relatively constant thickness, which also extends over the overlap area denoted by Ü, this equalization being achieved by the type of drive of the hollow body 4 described in connection with FIG. 1 and by the type of varnish described according to FIG 3 results.
  • the mode of operation described in connection with FIG. 3 also shows that this type of coating application readily decreases
  • the roto-engraving system can be used because the lacquer splitting along the tangent 22 in FIG. 3 and the higher peripheral speed of the hollow body 4 compared to the coating roller 2 means that the lacquer remaining on the surface of the hollow body when the lacquer bridges are separated from this surface adheres to this surface nestles and in this way covers the area between adjacent bridges of the paint. In this way, the gaps between the bridges deliberately placed next to one another for the transfer of lacquer in the roto-engraving method are uniformly covered, so that the roto-engraving structure is no longer recognizable after the hollow body 4 has circulated twice.

Description

Die Erfindung betrifft ein Verfahren und eine Vorrichtung zum Rundumlackieren von zylindrischen Hohlkörpern, wie Dosenrümpfen, bei dem die Hohlkörper auf um ihre Längsachse antreibbaren Dornen eines angetriebenen Dornenrades gehalten, gegen eine angetriebene, achsparallel zum Dornenrad verlaufende Lackierwalze eines Lackwerkes gedrückt und im Bereich der Berührung mit der Lackierwalze mit den Dornen entlang der Kontur der Walze geführt werden.The invention relates to a method and a device for the all-round painting of cylindrical hollow bodies, such as can hulls, in which the hollow bodies are held on thorns of a driven thorn wheel that can be driven about their longitudinal axis, pressed against a driven painting roller of a coating unit running axially parallel to the thorn wheel, and in the area of contact with the painting roller with the thorns are guided along the contour of the roller.

Das Rundumlackieren von zylindrischen Hohlkörpern, beispielsweise von Dosenrümpfen, erfolgt nach dem vorgenannten bekannten Verfahren in der Weise, dass die auf den antreibbaren Dornen eines umlaufend angetriebenen Dornenrades gehaltenen Hohlkörper mit den Dornen in eine Rotationsbewegung versetzt werden, so dass die Umfangsgeschwindigkeit der Hohlkörper im Bereich der Berührung mit der Lackierwalze die gleiche ist wie die Umfangsgeschwindigkeit der Lackierwalze, so dass Hohlkörper und Lackierwalze aufeinander abrollen und unter der Einwirkung des Druckes zwischen dem Hohlkörper und der Lackierwalze eine Lackübertragung von der Walze auf den Hohlkörper erfolgt. Zur Erzielung eines geschlossenen und möglichst gleichmässigen Lackauftrages auf den Hohlkörper wird die Berührung über die Dauer von zwei Umdrehungen des Hohlkörpers mit der Lackierwalze zuzüglich eines kurzen Überlappungsbereiches aufrechterhalten.The all-round painting of cylindrical hollow bodies, for example can bodies, takes place according to the aforementioned known method in such a way that the hollow bodies held on the drivable mandrels of a rotatingly driven thorn wheel are set in a rotational movement with the thorns, so that the peripheral speed of the hollow bodies in the region of Contact with the coating roller is the same as the peripheral speed of the coating roller, so that the hollow body and the coating roller roll on one another and under the action of the pressure between the hollow body and the coating roller, a coating transfer from the roller to the hollow body takes place. In order to achieve a closed and as uniform as possible coating application on the hollow body, contact is maintained over the duration of two revolutions of the hollow body with the painting roller plus a short overlap area.

Durch den in dem Berührungsbereich zwischen dem Hohlkörper und der Lackierwalze notwendigen Andruck wird der von der Lackierwalze zugeführte Lack gequetscht, so dass sich in dem Einzugsspalt zwischen den jeweils einander näherkommenden Bereichen des Hohlkörpers und der Lackierwalze ein Lackstau oder Lackaufbau bildet, welcher über die gesamte Berührungsdauer zwischen dem Hohlkörper und der Lackierwalze erhalten bleibt. In dem Auszugsspalt, welcher zwischen den voneinander weg bewegten Bereichen des Hohlkörpers und der Lackierwalze entsteht, erfolgt eine Lackspaltung, d.h. eine Längstrennung des zwischen dem Hohlkörper und der Oberfläche der Lackierwalze befindlichen Lackfilmes, wobei kein gleichmässiger Abriss erfolgt. Vielmehr entsteht an der engsten Stelle des Spaltes zunächst infolge der Dehnbarkeit des Lackes eine sich über den gesamten Spalt erstreckende durchgehende Brücke, welche mit zunehmender Spaltweite in eine Vielzahl von getrennten Einzelbrücken übergeht, die mit zunehmender Öffnungsweite des Spaltes kontinuierlich unter Verjüngung ihres mittleren Querschnittbereiches zerrissen und getrennt werden. Dabei entstehen unerwünschte Lacknebel. Ausserdem verbleiben auf den Oberflächen des Hohlkörpers und der Lackierwalze von dem Lack gebildete Strukturen, welche zwar mit dem blossen Auge nicht wahrnehmbar sind und z.T. auch wieder infolge der Viskosität des Lackes vermindert werden, jedoch nicht vollständig verschwinden, so dass ein, wenn auch nur geringfügig, strukturierter Lackauftrag auf die Oberfläche des Hohlkörpers erfolgt.Due to the pressure required in the contact area between the hollow body and the painting roller, the paint supplied by the painting roller is squeezed, so that a paint jam or build-up of paint forms in the feed gap between the respectively approaching areas of the hollow body and the painting roller, which builds up over the entire contact time between the hollow body and the painting roller is preserved. In the pull-out gap which is formed between the areas of the hollow body which are moved away from one another and the coating roller, there is a coating split, i.e. a longitudinal separation of the paint film located between the hollow body and the surface of the painting roller, with no uniform tearing off. Rather, at the narrowest point of the gap, due to the elasticity of the varnish, a continuous bridge is created which, with increasing gap width, merges into a large number of separate individual bridges, which with increasing opening width of the gap continuously tore and taper their central cross-sectional area be separated. This creates undesirable paint mist. In addition, structures formed by the lacquer remain on the surfaces of the hollow body and the coating roller, which are not perceptible to the naked eye and in some cases. can also be reduced again due to the viscosity of the lacquer, but not completely disappear, so that a structured, if only slight, lacquer application takes place on the surface of the hollow body.

Der Grad der Lackstruktur auf dem Hohlkörper hängt in starkem Masse von der Viskosität des Lackes sowie auch von der Umfangsgeschwindigkeit des Hohlkörpers und der Lackierwalze ab.The degree of the lacquer structure on the hollow body depends to a large extent on the viscosity of the lacquer and also on the peripheral speed of the hollow body and the coating roller.

Zur Erzielung der notwendigen Umfangsgeschwindigkeit der Hohlkörper werden die antreibbaren Dorne des Dornenrades mit den darauf gehaltenen Hohlkörpern lediglich auf einem kurzen Abschnitt ihrer Bewegungsbahn in Richtung zur Lackierwalze angetrieben. Während der Berührung der Hohlkörper mit der Lackierwalze erfolgt kein Antrieb der Dorne mehr, jedoch wird durch den Andruck der Walze gegen die Hohlkörper die synchrone Umfangsgeschwindigkeit der Lackierwalze und der Hohlkörper in etwa beibehalten. Die Umfangsgeschwindigkeit der Hohlkörper und der Lackierwalze beträgt bei dem bisher bekannten Rundumlackieren etwa 2 m/Sek. und kann maximal bis auf 6 m/Sek. gesteigert werden. Bei höheren Umfangsgeschwindigkeiten erfolgt eine Zerstäubung des Lackes während der Trennung der beschriebenen von dem Lack gebildeten Einzelbrücken, so dass ein Lacknebel entsteht, welcher unter allen Umständen zur Vermeidung von Funktionsstörungen an den Vorrichtungen zur Durchführung der Rundumlackierung und auch zur Vermeidung von Umweltbelastungen vermieden werden muss.In order to achieve the necessary peripheral speed of the hollow body, the drivable mandrels of the thorn wheel with the hollow bodies held thereon are driven only over a short section of their movement path in the direction of the painting roller. When the hollow bodies come into contact with the painting roller, the mandrels are no longer driven, but the synchronous peripheral speed of the painting roller and the hollow bodies is approximately maintained by the pressure of the roller against the hollow bodies. The circumferential speed of the hollow body and the coating roller is about 2 m / sec in the previously known all-round coating. and can be up to 6 m / sec. be increased. At higher peripheral speeds, the paint is atomized during the separation of the described individual bridges formed from the paint, so that a paint mist is formed which must be avoided under all circumstances to avoid malfunctions in the devices for carrying out the all-round painting and also to avoid environmental pollution.

Das Problem der Zerstäubung des Lackes bzw. die Verminderung der Neigung desselben zum Abschleudern wird in der DE-A 2504647 behandelt. Hier wird vorgeschlagen, das Auftragselement einer Lackiereinheit innerhalb eines von der Bahn mit den Halteelementen für die zu lackierenden Dosen umschlossenen Bereiches vorzusehen und so anzuordnen, dass es in Berührung mit den sich entlang der Bahn bewegenden Dosen treten kann. Ziel dieser Anordnung ist es, die lineare Geschwindigkeit der die Dosen tragenden Dorne in dem Bereich, in dem die Dosen in Berührung mit dem Umfang des Auftragselementes stehen, zu vermindern.The problem of atomizing the paint or reducing its tendency to spin off is dealt with in DE-A 2504647. It is proposed here to provide the application element of a painting unit within an area enclosed by the web with the holding elements for the cans to be painted and to arrange it so that it can come into contact with the cans moving along the web. The aim of this arrangement is to reduce the linear speed of the mandrels carrying the cans in the area in which the cans are in contact with the circumference of the application element.

Es ist weiterhin bekanntgeworden (DE-PS 1536978), zum Bedrucken oder Lackieren von Hohlkörpern, wie beispielsweise Tuben, die Halterungsspindeln für die Aufnahme der Hohlkörper und das Druck- bzw. Lackierwerk zum beliebigen Aufeinanderabstimmen der Umfangsgeschwindigkeiten jeweils getrennt stufenlos anzutreiben, um Hohlkörper mit verschieden grossen Durchmessern oder verschieden grossen Dicken mit ein und demselben Druckwerk bedrucken zu können und dabei einen annehmbaren Druck zu erzielen. Dabei sollte zwar ein gleichmässiges und einwandfreies Zerreiben der Druckfarbe ermöglicht, jedoch andererseits ein Vertwisten, d.h. Verdrehen bzw. Verzerren des Hohlkörpers, insbesondere der Tuben, vermieden werden. Dies ist jedoch nur erreichbar, wenn in der eingangs beschriebenen Weise die Umfangsgeschwindigkeiten des Hohlkörpers und des Druckwerkes im Bereich ihrer Berührung etwa gleich gross sind. Dabei kann (DE-PS 2121725) auch vorgesehen sein, die Umfangsgeschwindigkeit des an der Halterungsspindel sitzenden Hohlkörpers gegenüber derjenigen des mit ihm zusammenwirkenden für einen bestimmten Sollumfang des Hohlkörpers ausgelegten rotierenden Druckträgers um einen bestimmten, der Differenz zwischen Soll- und Ist-Umfang des Hohlkörpers entsprechenden Betrag veränderlich einzustellen, um ein für einen bestimmten Hohlkörperumfang festgelegtes Klischee auch noch zum einwandfreien Bedrucken von anderen noch im Toleranzbereich liegenden Umfangsgrössen benutzen zu können. Auf diese Weise soll erreicht werden, dass ein einwandfreier Druck durch bessere Verreibung der Farbe und eine verzerrungsfreie Abbildung auf dem Hohlkörper auch dann erfolgt, wenn die Aussendurchmesser der Hohlkörper unterschiedlich sind.It has also become known (DE-PS 1536978) for the printing or painting of hollow bodies, such as tubes, the mounting spindles for receiving the hollow bodies and the printing or painting unit, for the purpose of coordinating the circumferential speeds, in each case separately and continuously to drive hollow bodies with different to be able to print large diameters or different thicknesses with one and the same printing unit and thereby achieve an acceptable print. Although the ink should be rubbed evenly and properly, twisting, ie twisting or distorting of the hollow body, in particular the tubes, should be avoided. However, this can only be achieved if, in the manner described at the beginning, the peripheral speeds of the hollow body and of the printing unit are approximately the same in the area of their contact are big. It can also be provided (DE-PS 2121725) that the circumferential speed of the hollow body seated on the mounting spindle compared to that of the cooperating rotating pressure carrier designed for a specific desired circumference of the hollow body by a certain difference between the desired and actual circumference of the hollow body adjust the corresponding amount variably in order to be able to use a cliché defined for a specific hollow body circumference for the perfect printing of other circumferential sizes that are still within the tolerance range. In this way, it should be achieved that perfect printing through better rubbing of the color and distortion-free imaging on the hollow body also takes place when the outer diameters of the hollow bodies are different.

Ausgehend von dem einleitend näher beschriebenen Verfahren zum Rundumlackieren von zylindrischen Hohlkörpern, wie Dosenrümpfen, liegt der Erfindung die Aufgabe zugrunde, eine Verbesserung des Lackauftrages durch Vergleichmässigung des Lacküberzuges auf dem Hohlkörper zu erzielen, so dass eine Verminderung des Lackbedarfes bei Aufrechterhaltung der optisch wahrnehmbaren Abdeckqualität oder bei gleicher Lackmenge wie bisher eine Verbesserung der Abdeckqualität erreicht werden. Ausserdem soll die Verwendung hochviskoser Lacke mit wenig Lösungsmittelanteilen auch bei wirtschaftlich vertretbaren Umfangsgeschwindigkeiten ermöglicht werden.On the basis of the process described in the introduction for the all-round painting of cylindrical hollow bodies, such as can bodies, the object of the invention is to achieve an improvement in the paint application by uniformizing the paint coating on the hollow body, so that a reduction in the paint requirement while maintaining the optically perceptible covering quality or with the same amount of paint as before, an improvement in the covering quality can be achieved. In addition, the use of highly viscous paints with little solvent content should also be made possible at economically justifiable peripheral speeds.

Zur Lösung vorstehender Aufgabe kennzeichnet sich das eingangs genannte Verfahren erfindungsgemäss dadurch, dass die Hohlkörper und die Lackierwalze getrennt mit unterschiedlichen Umfangsgeschwindigkeiten zwischen mindestens 2 und maximal 6 m/Sek. und die Hohlkörper während der Druckberührung mit der Lackierwalze, bezogen auf die Umfangsgeschwindigkeit der Lackierwalze, mit einer um 10 bis 80% höheren Umfangsgeschwindigkeit angetrieben werden, wobei die Hohlkörper zu Beginn und zum Ende der Druckberührung mit der Lackierwalze mit einer höheren umfänglichen Differenzgeschwindigkeit angetrieben werden als im Mittelbereich der Berührung.To achieve the above object, the method mentioned at the outset is characterized in that the hollow body and the coating roller are separated with different peripheral speeds between at least 2 and a maximum of 6 m / sec. and the hollow bodies are driven at a peripheral speed which is 10 to 80% higher in relation to the peripheral speed of the coating roller during pressure contact with the coating roller, the hollow bodies being driven at a higher peripheral differential speed at the beginning and at the end of pressure contact with the coating roller in the middle of the touch.

Die merkbar höhere Umfangsgeschwindigkeit des Hohlkörpers gegenüber der Lackierwalze ist in ihrer Grössenordnung und auch in ihrer Auswirkung mit der möglichen Differenzgeschwindigkeit zwischen einem Druckträger und dem Hohlkörper zum Ausgleich zwischen Soll- und Ist-Umfang des Hohlkörpers nach dem bekannten Verfahren nicht vergleichbar. Sie bewirkt ein hydrodynamisches Auftragen des Lackfilmes auf den Hohlkörper. Die Lackschicht wirkt dabei gleichzeitig wie ein Schmiermittel und wird durch die höhere Umfangsgeschwindigkeit des Hohlkörpers im Vergleich zur Lackierwalze im Einzugsspalt in solchem Masse eingezogen, dass ein Lackstau in diesem Spalt nicht entsteht. Im Bereich der Trennung wird der Lack nicht mehr wie bei der Gleichlauf-Walzenlackierung in der Form getrennt, dass ein ausschliessliches Abheben der zusammenwirkenden Flächen des Hohlkörpers und der Lackierwalze unter Bildung von Brücken und Fäden während der Lackspaltung erfolgt, sondern es wird infolge der höheren Umfangsgeschwindigkeit des Hohlkörpers der Lackfilm im Bereich des Hohlkörperradius mehr oder weniger abgeschert. Auf diese Weise wird im Überlappbereich des Auftrages die sonst beim Abheben des Hohlkörpers von der Lackierwalze dort verbleibende aus dem Einzugsspalt stammende Anhäufung des Lackes vermieden und gleichzeitig erreicht, dass die durch die Lackspaltung und den Lackabriss mit der Fadenbildung entstehende Struktur nicht entsteht, so dass ein beruhigter und vergleichmässigter Lackfilm auf die Hohlkörper aufgebracht wird. Diese führt dazu, dass mit einer gleichen Lackmenge wie bei dem bekannten Verfahren eine bessere Opazität des Lackfilmes über den Umfang des Hohlkörpers oder bei gleicher Opazität eine Lackersparnis erreicht werden, wobei auch die Überlappungsbereiche optisch noch weniger in Erscheinung treten, als dies bei bekannten Lackierverfahren der Fall ist.The noticeably higher peripheral speed of the hollow body compared to the coating roller is not comparable in its size and also in its effect with the possible differential speed between a printing medium and the hollow body to compensate for the desired and actual circumference of the hollow body according to the known method. It effects a hydrodynamic application of the paint film on the hollow body. At the same time, the lacquer layer acts like a lubricant and, due to the higher peripheral speed of the hollow body compared to the lacquer roller, is drawn into the feed gap to such an extent that there is no lacquer build-up in this gap. In the separation area, the paint is no longer separated as in the case of synchronized roller painting in such a way that the interacting surfaces of the hollow body and the painting roller are lifted off exclusively with the formation of bridges and threads during the paint splitting, but rather due to the higher peripheral speed of the hollow body, the paint film is more or less sheared off in the area of the hollow body radius. In this way, in the overlap area of the order, the accumulation of the paint that would otherwise remain there when the hollow body is lifted from the painting roller is avoided, and at the same time the structure created by the paint splitting and the paint tear-off with the thread formation is not formed, so that a calmed and even paint film is applied to the hollow body. This means that with the same amount of lacquer as in the known method, better opacity of the lacquer film over the circumference of the hollow body or with the same opacity, lacquer savings are achieved, the overlapping areas also appearing less visually than is the case with known lacquer methods Case is.

Infolge der geänderten Verhältnisse bei der Lackspaltung durch die überwiegende Schertrennung des Lackfilmes im Bereich des Auszugsspaltes zwischen dem Hohlkörper und der Lackierwalze wird auch bei höheren Umfangsgeschwindigkeiten die Gefahr des Erzeugens von Lacknebel vermieden. Der Lackabriss orientiert sich vielmehr ohne nennenswerte Fadenbildung zur Oberfläche des Hohlkörpers hin, so dass der Lackspaltwinkel, d.h. der Winkel zwischen den sich trennenden Lackbrücken im Auszugsspalt, mit zunehmender Differenzgeschwindigkeit des Hohlkörpers gegenüber der Lackierwalze verkleinert wird.As a result of the changed conditions during the lacquer splitting due to the predominant shear separation of the lacquer film in the area of the pull-out gap between the hollow body and the lacquer roller, the risk of lacquer mist being generated is avoided even at higher peripheral speeds. Rather, the lacquer tear is oriented towards the surface of the hollow body without any notable thread formation, so that the lacquer gap angle, i.e. the angle between the separating lacquer bridges in the pull-out gap is reduced with increasing speed of difference of the hollow body compared to the painting roller.

Infolge der höheren Umfangsgeschwindigkeit des Hohlkörpers in bezug auf die Lackierwalze kann die Rundumlackierung des Hohlkörpers gegenüber der Gleichlauflackierung über einen geringeren Umfangsbereich der Lackierwalze erfolgen, so dass der mit dem Dornenrad zusammenwirkende Umfangsbereich der Lackierwalze gegenüber der bekannten Ausführung verkürztwerden kann und somit eine kürzere Auslenkstrecke der Dorne aus der Kreisbahn erforderlich ist.As a result of the higher peripheral speed of the hollow body in relation to the painting roller, the all-round painting of the hollow body can take place over a smaller peripheral area of the painting roller compared to the synchronous painting, so that the peripheral area of the painting roller interacting with the mandrel wheel can be shortened compared to the known design and thus a shorter deflection distance of the mandrels from the circular path is required.

Durch das Merkmal der erhöhten umfänglichen Differenzgeschwindigkeit zu Beginn und zum Ende der Druckberührung mit der Lackierwalze im Vergleich zum Mittelbereich der Berührung wird zu Beginn und gegen Ende des Lackiervorganges ein im Verhältnis zu dem Zwischenbereich in seiner Dicke dünnerer Lackfilm aufgebracht. Da der Anfangs- und Endbereich der Rundumlackierung die Überlappungszone bilden, erfolgt somit eine weitgehende Vergleichmässigung des Lackfilmes in seiner Dicke auch über den Bereich der genannten Überlappzone, so dass die Dicke des Lackfilmes in dieser Zone etwa der Dicke des Lackfilmes auf dem übrigen Umfangsbereich des Hohlkörpers entspricht.Due to the feature of the increased circumferential differential speed at the beginning and at the end of the pressure contact with the coating roller in comparison with the central region of the contact, a coating film which is thinner in thickness than the intermediate region is applied at the beginning and towards the end of the coating process. Since the start and end area of the all-round paint form the overlap zone, the paint film is largely evened out over the area of the mentioned overlap zone, so that the thickness of the paint film in this zone is approximately the same as the thickness of the paint film on the remaining peripheral area of the hollow body corresponds.

Schliesslich wird es durch das neue Verfahren auch möglich, Wasserlacke zu verarbeiten, welche bekanntlich ein schlechtes Fliessverhalten aufweisen und für die Gleichlauf-Drucklackierung nicht geeignet sind.Ultimately, the new process will it is also possible to process water-based paints, which are known to have poor flow properties and are not suitable for synchronous printing painting.

Als besonders zweckmässig hat es sich herausgestellt, die Hohlkörper mit einer Umfangsge- schwindigkeit von nahe 6 m/Sek. und die Lackierwalze mit einer Umfangsgeschwindigkeit von etwa 4 bis 4,3 m/Sek. anzutreiben. Bei diesen Umfangsgeschwindigkeiten konnten erfahrungsgemäss besonders günstige Ergebnisse bezüglich eines gleichmässigen Lackauftrages erzielt werden.As a particularly expedient, it has been found, the hollow body having a Umfangsge- schwindi g speed of near 6 m / sec. and the coating roller with a peripheral speed of about 4 to 4.3 m / sec. to drive. Experience has shown that at these peripheral speeds it was possible to achieve particularly favorable results with regard to a uniform coating application.

Durch die beschriebene Art der Lacktrennung bei dem neuen Verfahren ist es möglich und zweckmässig, das Verfahren so zu gestalten, dass die Lackübertragung durch Roto-Gravur-Offset erfolgt. Diese Art der Lackübertragung ist erstmalig durch die Erfindung möglich. Bei einer Gleichlaufdrucklackierung lässt sich das Roto-Gravur-Offset-Druckverfahren praktisch nicht anwenden, da hierdurch eine verstärkte Strukturbildung einerseits durch die Gravur selbst, andererseits bei der Lackspaltung auftritt, die erfindungsgemäss durch die höhere Umfangsgeschwindigkeit des Hohlkörpers gegenüber der Lackierwalze ausgeglichen wird.The described type of lacquer separation in the new method makes it possible and expedient to design the method in such a way that the lacquer transfer is carried out by roto-gravure offset. This type of paint transfer is possible for the first time through the invention. The rotary gravure offset printing process cannot be used practically in the case of synchronous printing coating, since this results in increased structure formation on the one hand due to the engraving itself and on the other hand during coating splitting, which according to the invention is compensated for by the higher peripheral speed of the hollow body compared to the coating roller.

Zur Durchführung des beschriebenen neuen Verfahrens geht die Erfindung von einer Vorrichtung aus mit einer rotierend angetriebenen Lackwalze und einem rotierend angetriebenen Dornenrad, dessen senkrecht zur Radebene angeordneten Dorne um ihre Längsachse frei drehbar und zur Anpassung ihrer Bewegungsbahn an die in die Kreisbahn der Dorne ragende Umfangsfläche der Lackierwalze über einen Teil des Radumfanges mittels Steuerkurven in Richtung quer zu ihrer Längsachse verschiebbar an dem Dornenrad gehalten sind. Erfindungsgemäss ist diese bekannte Vorrichtung so ausgebildet, dass eine an den Dornen im Bereich vor ihrer Auslenkung aus der Kreisbahn zur Anpassung an die Umfangsfläche der Lackierwalze bis zum Beginn der Auslenkung und wiederum gegen Ende der Auslenkung angreifende und die Dorne um ihre Längsachse in Rotation versetzende regelbare Antriebseinrichtung vorgesehen ist. Dabei ist es zweckmässig, wenn die Antriebseinrichtung aus einem endlosen Riementrieb besteht, dessen Antriebstrum zwischen zwei in Bewegungsrichtung des Dornenrades vor und hinter dem Auslenkbereich der Dorne angeordneten Umlenkwalzen gespannt ist und sich auf den Dornen im Bereich vor und zu Beginn sowie gegen Ende der Auslenkung aus der Kreisbahn abstützt.To carry out the described new method, the invention is based on a device with a rotatingly driven coating roller and a rotatingly driven mandrel wheel, the mandrels of which are arranged perpendicular to the wheel plane and can be freely rotated about their longitudinal axis and to adapt their movement path to the peripheral surface of the mandrel projecting into the circular path of the mandrels Paint roller over a part of the wheel circumference by means of control curves in the direction transverse to its longitudinal axis are held on the thorn wheel. According to the invention, this known device is designed such that a controllable on the mandrels in the area before their deflection from the circular path to adapt to the peripheral surface of the coating roller until the beginning of the deflection and again towards the end of the deflection and the rotation of the mandrel about its longitudinal axis Drive device is provided. It is expedient if the drive device consists of an endless belt drive, the drive section of which is stretched between two deflection rollers arranged in the direction of movement of the mandrel wheel in front of and behind the deflection area of the mandrels and on the mandrels in the area before and at the beginning and towards the end of the deflection supports the circular path.

Diese Antriebsvorrichtung lässt sich besonders einfach gestalten und durch die Anordnung der Umlenkwalzen so ausbilden, dass die Dorne nach Beginn des Lackiervorganges von dem antreibbaren Trum infolge ihrer Auslenkung aus der Kreisbahn freikommen, jedoch gegen Ende des Lackiervorganges wiederum in die Bewegungsbahn des Trums gelangen und daher von dem Trum wieder mitgenommen werden. Auf diese Weise werden die Dorne mit den darauf befindlichen Hohlkörpern zu Beginn und gegen Ende der Druckberührung mit der Lackierwalze mit einer höheren umfänglichen Differenzgeschwindigkeit angetrieben als im Mittelbereich der Berührung.This drive device can be designed in a particularly simple manner and can be designed by the arrangement of the deflecting rollers in such a way that the mandrels are released from the drivable strand as a result of their deflection from the circular path after the start of the painting process, but again enter the path of movement of the strand towards the end of the painting process and therefore from the run can be taken again. In this way, the mandrels with the hollow bodies located thereon are driven at the beginning and towards the end of pressure contact with the coating roller with a higher circumferential differential speed than in the middle region of the contact.

Weitere Einzelheiten der Erfindung werden anhand der beigefügten Zeichnungen erläutert.Further details of the invention will be explained with reference to the accompanying drawings.

Es zeigen:

  • Fig. 1 in schematischer Darstellung die Arbeitsweise der Vorrichtung zur Durchführung des Verfahrens,
  • Fig. schematisch und in vergrösserter Darstellung die Verhältnisse beim Lackauftrag nach dem Stande derTechnik,
  • Fig.3 ähnlich wie Fig.2 den Lackauftrag, jedoch nach dem erfindungsgemäss ausgebildeten Verfahren,
  • Fig. 4 wiederum schematisch eine Abwicklung des Lackauftrages, wie er bei zweimaliger Rundumlackierung mit Überlappbereich durch die Erfindung erreicht wird.
Show it:
  • 1 is a schematic representation of the operation of the device for performing the method,
  • 1 shows schematically and in an enlarged view the conditions when applying paint according to the prior art,
  • 3 similar to FIG. 2 the paint application, but according to the method designed according to the invention,
  • Fig. 4 in turn schematically a processing of the paint application, as is achieved by the invention in two round painting with overlap area.

In der Fig. 1 ist rein schematisch ein Teil des Dornenrades 1 wiedergegeben, welches mit einer Lackierwalze 2 zusammenwirkt. Das Dornenrad 1 ist um seine Mittelachse 1a in Richtung des Pfeiles 1 b antreibbar und auf seinem Umfang mit Dornen 3 ausgerüstet, welche in gleichmässigem Abstand verteilt auf dem Umfang des Dornenrades 1 angeordnet sind. Die Dorne 3 sind dabei in dem Dornenrad 1 drehbar gelagert und um ihre Längsachsen rotierbar gehalten. Auf den Dornen 3 sind die zu lackierenden Hohlkörper 4 drehsicher gehalten. Sie werden in bekannter Weise den Dornen 3 zugeführt und auf diese aufgeschoben sowie nach der erfolgten Rundumlakkierung wieder abgenommen und der weiteren Verarbeitung zugeleitet.In Fig. 1, a part of the mandrel wheel 1 is shown purely schematically, which cooperates with a painting roller 2. The spike wheel 1 can be driven about its central axis 1a in the direction of the arrow 1b and is equipped on its circumference with spikes 3, which are arranged at a uniform spacing on the circumference of the spike wheel 1. The mandrels 3 are rotatably mounted in the mandrel wheel 1 and held rotatably about their longitudinal axes. On the mandrels 3, the hollow body 4 to be painted is held against rotation. They are fed to the mandrels 3 in a known manner and pushed onto them and, after the all-round lacquering, removed again and passed on for further processing.

Die Dorne 3 sind mittels einer, in der Zeichnung nicht wiedergegebenen, Steuerungseinrichtung zur Anpassung an die Bewegungsbahn der Lakkierwalze 2, welche um ihre Mittelachse 5 rotierend angetrieben wird, in Richtung quer zu ihrer Längsachse verschiebbar an dem Dornenrad 1 gehalten, so dass die Dorne 3 aus der insgesamt mit 6 bezeichneten Kreisbahn ihrer Mittelachsen im Bereich der Lackierwalze 2 entlang der Bahn 6a bewegt werden und dabei im Andruck mit der Lackierwalze 2 bleiben, welche in Richtung des Pfeiles 7 rotierend angetrieben wird.The mandrels 3 are held on the mandrel wheel 1 by means of a control device, not shown in the drawing, for adapting to the movement path of the coating roller 2, which is driven to rotate about its central axis 5, in the direction transverse to its longitudinal axis, so that the mandrels 3 are moved out of the circular path of their central axes, designated overall by 6, in the region of the coating roller 2 along the path 6a and remain in contact with the coating roller 2, which is driven to rotate in the direction of the arrow 7.

Zum Antrieb der Dorne 3 dient ein endloser Riementrieb 9, welcher in Richtung des Pfeiles 8 umläuft und um die Umlenkwalzen 10, 11 und 12 geführt ist, von denen wenigstens eine gleichzeitig als Antriebswalze ausgebildet ist. Man erkennt, dass das Trum 9a des Riementriebes 9 auf den Dornen 3 aufliegt, um diese vor ihrer Auslenkung und Druckberührung mit der Lackierwalze 2 um ihre Mittelachsen anzutreiben und in Rotation zu versetzen. Im Bereich der Druckberührung der Dorne 3 bzw. der auf diesen gehaltenen Hohlkörper 4 mit der Lackierwalze 2 entfernen sich die Dorne 3 durch ihre Führung entlang der Bewegungsbahn 6a von dem Trum 9a, so dass der Antrieb in diesem Bereich unterbrochen ist, jedoch noch vor dem Abheben der Hohlkörper von der Lackierwalze 2 wieder mit dem Trum 9a in Berührung kommen, so dass sie gegen Ende der Druckberührung mit der Lackierwalze wieder angetrieben werden. In dem dargestellten Beispiel werden die Dorne 3a und 3b noch bzw. wieder über das Trum 9a des Riementriebes 9 angetrieben, während der Dorn 3c mit dem Trum 9a ausser Berührung ist, jedoch auf der Umfangsfläche der Lackierwalze 2 anliegt.An endless belt drive 9, which rotates in the direction of arrow 8 and is guided around the deflection rollers 10, 11 and 12, of which at least one is simultaneously designed as a drive roller, is used to drive the mandrels 3. It can be seen that the run 9a of the belt drive 9 rests on the mandrels 3 in order to drive them before their deflection and pressure contact with the painting roller 2 about their central axes and to set them in rotation. In the area of pressure contact between the mandrels 3 or the hollow bodies 4 held thereon with the painting roller 2, the mandrels 3 move away from the strand 9a by their guidance along the movement path 6a, so that the driven in this area is interrupted, but before lifting the hollow body from the painting roller 2 come back into contact with the strand 9a, so that they are driven towards the end of the pressure contact with the painting roller. In the example shown, the mandrels 3a and 3b are still or again driven via the run 9a of the belt drive 9, while the mandrel 3c is out of contact with the run 9a, but lies on the peripheral surface of the coating roller 2.

Der Riementrieb 9 bringt die Dorne 3 auf eine Umfangsgeschwindigkeit, welche höher ist als die Umfangsgeschwindigkeit der Lackierwalze 2. Die Umfangsgeschwindigkeiten der Lackierwalze und der Dorne betragen dabei zwischen 2 und maximal 6 m/Sek., wobei die Umfangsgeschwindigkeit der Dorne 3 bzw. der darauf gehaltenen Hohlkörper 4 während der Druckberührung mit der Lackierwalze 2 um 10 bis 80% höher liegt als die Umfangsgeschwindigkeit der Lackierwalze 2. Hierdurch ergeben sich für den Lackauftrag von der Lackierwalze 2 auf die Hohlkörper 4 völlig andere Verhältnisse, als sie bei einem Gleichlauf, also bei gleicher Umfangsgeschwindigkeit der Hohlkörper und der Lackierwalze, auftreten.The belt drive 9 brings the mandrels 3 to a peripheral speed which is higher than the peripheral speed of the coating roller 2. The peripheral speeds of the coating roller and the mandrels are between 2 and a maximum of 6 m / sec., The peripheral speed of the mandrels 3 and / or thereon held hollow body 4 during the pressure contact with the painting roller 2 is 10 to 80% higher than the peripheral speed of the painting roller 2. This results in completely different conditions for the paint application from the painting roller 2 to the hollow body 4 than they do in a synchronous operation, that is same peripheral speed of the hollow body and the coating roller occur.

Die vorgenannten Unterschiede werden anhand der Fig. 2 und 3 näher erläutert.The aforementioned differences are explained in more detail with reference to FIGS. 2 and 3.

Fig. gibt schematisch die Verhältnisse bei einer Gleichlauf-Drucklackierung wieder. Bei diesem Verfahren bewegt sich die Umfangsfläche 2a der Lackierwalze 2 mit einer Geschwindigkeit V2 in Richtung des Pfeiles 13. Der Hohlkörper 4 wird ebenfalls angetrieben bzw. durch die Lakkierwalze 2 mitgenommen mit einer Geschwindigkeit V, in Richtung des Pfeiles 14. Bei gleicher Geschwindigkeit, also VI = V2, erfolgt während der in der Fig. wiedergegebenen Andruckstellung des Hohlkörpers 4 gegen die Lackierwalze 2 der Lackauftrag, wobei sich im Einzugsspalt 15 ein Lackaufbau 16 bildet, während im Bereich des Auszugsspaltes 17 zunächst Lackbrücken 18 grösserer Abmessungen entstehen, welche sich mit zunehmender Trennung der Oberflächen des Hohlkörpers 4 und der Lackierwalze 2 unterteilen und unter Verminderung des Querschnittes in ihrem Mittelbereich getrennt werden, wobei in dem Trennungsbereich noch Lackfäden bestehen bleiben, bis auch diese zerreissen, so dass auf der Oberfläche des Hohlkörpers 4 und auf der Oberfläche der Lackierwalze eine in der Fig. 2 vergrössert dargestellte Struktur 19 bzw. 20 des Lackauftrages entsteht, welche je nach Viskosität des Lackes mehr oder weniger ausgeprägte Spitzen zeigt, wie dies in der Figur angedeutet ist.Fig. Schematically shows the conditions in a synchronous printing coating. In this method, the peripheral surface 2a of the coating roller 2 moves at a speed V 2 in the direction of the arrow 13. The hollow body 4 is also driven or carried along by the coating roller 2 at a speed V, in the direction of the arrow 14. At the same speed, V I = V 2 , the paint application takes place during the pressing position of the hollow body 4 against the painting roller 2 shown in FIG. 1, a paint build-up 16 forming in the draw-in gap 15, while in the area of the draw-out gap 17 there are initially paint bridges 18 of larger dimensions, which subdivide with increasing separation of the surfaces of the hollow body 4 and the coating roller 2 and are separated with a reduction in the cross section in their central region, lacquer threads still remaining in the separation region until these also tear, so that on the surface of the hollow body 4 and on the Surface of the coating roller is an enlarged view in FIG. 2 llte structure 19 or 20 of the paint application arises which, depending on the viscosity of the paint, shows more or less pronounced peaks, as indicated in the figure.

Die Trennung des Lackes, also die Lackspaltung, erfolgt bei dieser Art der Rundumlackierung etwa entlang der Winkelhalbierenden 21, wobei der gesamte Winkel als Lackspaltwinkel bezeichnet wird.In this type of all-round painting, the lacquer is separated, that is to say the lacquer splitting, approximately along the bisector 21, the entire angle being referred to as the lacquer gap angle.

Bei der Rundumlackierung nach der Erfindung gemäss Fig. stellen sich völlig andere Verhältnisse ein. Durch die höhere Umfangsgeschwindigkeit V, des Hohlkörpers 4 im Vergleich zur Umfangsgeschwindigkeit V2 der Lackierwalze 2 wird im Einzugsspalt 15 der aus Fig.2 ersichtliche Lackaufbau 16 verhindert. Es wird weiterhin im Auszugsspalt 17 durch die höhere Umfangsgeschwindigkeit des Hohlkörpers 4 eine Lacktrennung bzw. -spaltung bewirkt, welche zum Hohlkörper 4 hin orientiert ist, d.h. es erfolgt etwa tangential zu dem Hohlkörper 4, also etwa in Richtung der strichpunktiert wiedergegebenen Ebene 22, die Lacktrennung, welche sich nach Art eines Scherganges vollzieht, so dass die in der Fig. 2 wiedergegebene Struktur 19 bzw. 20 auf dem Hohlkörper 4 sowie der Lackierwalze 2 vermieden wird.In the all-round painting according to the invention shown in FIG., Completely different conditions arise. Due to the higher peripheral speed V of the hollow body 4 compared to the peripheral speed V 2 of the coating roller 2, the coating structure 16 shown in FIG. 2 is prevented in the feed nip 15. It is further effected in the pull-out gap 17 by the higher peripheral speed of the hollow body 4, a lacquer separation or splitting, which is oriented towards the hollow body 4, that is, it takes place approximately tangentially to the hollow body 4, i.e. approximately in the direction of the dash-dotted plane 22, the Paint separation, which takes place in the manner of a shear gear, so that the structure 19 or 20 shown in FIG. 2 on the hollow body 4 and the painting roller 2 is avoided.

Der Lackauftrag einer Rundumlackierung der Hohlkörper 4 bei zweifachem Umlauf während des Lackiervorganges zuzüglich einer Überlappungszone führt bei der beschriebenen Arbeitsweise der Anordnung nach Fig. 3 zu einem Lackauftrag, wie er in der Fig. 4 wiedergegeben ist.The paint application of an all-round painting of the hollow bodies 4 in two cycles during the painting process plus an overlap zone leads to a paint application in the described mode of operation of the arrangement according to FIG. 3, as shown in FIG. 4.

Die Hohlkörper 4 werden bis zum Beginn ihrer Druckberührung mit der Lackierwalze 2 durch den Riementrieb 9 auf eine relativ hohe Differenzgeschwindigkeit gegenüber der Lackierwalze 2 gebracht, so dass zu Beginn des Lackauftrages nur ein verhältnismässig dünner Lackfilm auf die Oberflächen der Hohlkörper 4 aufgetragen wird. Dadurch, dass die Hohlkörper 4 nach Beginn der Druckberührung mit der Lackierwalze 2 von dem Antriebstrum 9a abgehoben werden, verringert sich die Differenz ihrer Umfangsgeschwindigkeit gegenüber der Umfangsgeschwindigkeit der Lackierwalze durch die Gleitreibung, so dass der Lackauftrag allmählich stärker wird, bis gegen Ende des Lackiervorganges ein erneuter Antrieb des zugehörigen Dornes 3 durch den erneuten Angriff des Riementriebes 9 bzw. 9a erfolgt.The hollow bodies 4 are brought by the belt drive 9 to a relatively high differential speed with respect to the painting roller 2 until their pressure contact with the painting roller 2, so that only a relatively thin coating film is applied to the surfaces of the hollow bodies 4 at the beginning of the coating application. Because the hollow bodies 4 are lifted from the drive strand 9a after the pressure contact with the painting roller 2 begins, the difference in their peripheral speed compared to the peripheral speed of the painting roller is reduced by the sliding friction, so that the paint application gradually increases until the end of the painting process renewed drive of the associated mandrel 3 by the renewed attack of the belt drive 9 or 9a.

Während des ersten Umlaufes der Hohlkörper 4, der in der Abwicklung in Fig. 4 mit D1 dargestellt ist, erfolgt der in vergrössertem Massstab dargestellte Lackauftrag 23, welcher als Unterlage 231 des zweiten Lackauftrages während des zweiten Umlaufes D2 dient. Dieser Lackauftrag ist in Figur 4 mit 24 bezeichnet. Der Lackauftrag 24 wächst in seiner Dicke bis zum Wiederantrieb des entsprechenden Hohlkörpers gegen Ende der Rundumlackierung. Dieser Zeitpunkt bzw. dieser Bereich der Umfangsfläche des Hohlkörpers 4 ist in der Abwicklung der Fig. 4 bei 25 angedeutet. Infolge der nunmehr eintretenden Erhöhung der Differenzgeschwindigkeit wird der Lackauftrag ensprechend der Fläche 26 in seiner Dicke wieder vermindert, bis der Hohlkörper 4 abhebt. Hierdurch ergibt sich ein Lackauftrag, wie er in Fig. 4 durch die schraffierten Flächen dargestellt ist. Man erkennt, dass dieser Lackauftrag eine verhältnismässig gleichbleibende Dicke zeigt, die sich auch über den mit Ü bezeichneten Überlappbereich erstreckt, wobei sich diese Vergleichmässigung durch die in Verbindung mit der Figur 1 beschriebene Art des Antriebes der Hohlkörper 4 sowie durch die beschriebene Art Lackspaltung gemäss der Darstellung nach Fig. 3 ergibt.During the first circulation of the hollow body 4, which is shown in the development in FIG. 4 with D 1 , the lacquer application 23 shown on an enlarged scale takes place, which serves as a base 231 of the second lacquer application during the second circulation D 2 . This paint application is designated by 24 in FIG. The paint application 24 increases in thickness until the corresponding hollow body is driven again towards the end of the all-round painting. This point in time or this area of the peripheral surface of the hollow body 4 is indicated at 25 in the development of FIG. 4. As a result of the increase in the differential speed that now occurs, the thickness of the paint application is reduced again corresponding to the area 26 until the hollow body 4 lifts off. This results in a paint application, as shown in Fig. 4 by the hatched areas. It can be seen that this varnish application has a relatively constant thickness, which also extends over the overlap area denoted by Ü, this equalization being achieved by the type of drive of the hollow body 4 described in connection with FIG. 1 and by the type of varnish described according to FIG 3 results.

Die im Zusammenhang mit Fig. 3 beschriebene Wirkungsweise lässt auch erkennen, dass bei dieser Art des Lackauftrages ohne weiteres nach dem Roto-Gravur-System gearbeitet werden kann, da durch die Lackspaltung entlang der Tangente 22 in Fig.3 und die höhere Umfangsgeschwindigkeit des Hohlkörpers 4 gegenüber der Lackierwalze 2 der bei der Trennung der Lackbrücken auf der Oberfläche der Hohlkörper verbleibende Lack sich an diese Oberfläche anschmiegt und auf diese Weise den Bereich zwischen benachbarten Brücken des Lackes überdeckt. Auf diese Weise werden die Zwischenräume zwischen den beim Roto-Gravur-Verfahren bewusst dicht nebeneinander zur Lackübertragung vorgesehenen Brücken gleichmässig überdeckt, so dass die Roto-Gravur-Struktur nach dem zweimaligen Umlauf der Hohlkörper 4 nicht mehr erkennbar ist.The mode of operation described in connection with FIG. 3 also shows that this type of coating application readily decreases The roto-engraving system can be used because the lacquer splitting along the tangent 22 in FIG. 3 and the higher peripheral speed of the hollow body 4 compared to the coating roller 2 means that the lacquer remaining on the surface of the hollow body when the lacquer bridges are separated from this surface adheres to this surface nestles and in this way covers the area between adjacent bridges of the paint. In this way, the gaps between the bridges deliberately placed next to one another for the transfer of lacquer in the roto-engraving method are uniformly covered, so that the roto-engraving structure is no longer recognizable after the hollow body 4 has circulated twice.

Da durch das neue Verfahren praktisch keine Lackfäden gezogen werden bzw. die Lackfäden sich schmiegend an die Umfangsfläche der Hohlkörper 4 anlegen, ist es möglich, ohne die Gefahr einer Vernebelung des Lackes mit hoher Umfangsgeschwindigkeit bis zu 6 m/Sek. zu arbeiten, wobei auch Lacke verarbeitet werden können, die ein ungünstiges Fliessverhalten zeigen, wie beispielsweise Lacke, die auf Wasserbasis hergestellt werden.Since practically no paint threads are drawn by the new method or the paint threads nestle against the circumferential surface of the hollow body 4, it is possible without the risk of atomizing the paint at high peripheral speeds of up to 6 m / sec. to work, it also being possible to process paints that show an unfavorable flow behavior, such as paints that are produced on a water basis.

Claims (5)

1. Procedure for overall coating of cylindrical hollow bodies (4) such as can bodies, in which the hollow bodies (4) are held on mandrels (3) which may be driven round their longitudinal axis and are positioned on a driven mandrel wheel (1), pressed against a driven coating roller (2) of a coating mechanism, which extends parallel to the mandrel wheel axis, and guided together with the mandrels (3) along the contour of the roller while in contact with the coating roller (2), characterized by the hollow bodies (4) and the coating roller (2) being driven at different circumferential speeds of between a minimum of 2 and a maximum of 6 m per second and the hollow bodies, while in contact with the coating roller, being driven at a circumferential speed that is 10 to 80% higher than the circumferential speed of the coating roller (2), and the hollow bodies (4) being driven at a higher circumferential differential speed at the start and at the end of the zone of contact with the coating roller (2) than in the middle of the zone of contact.
2. Procedure in accordance with claim 1, characterized by the hollow bodies (4) being driven at a circumferential speed of nearly 6 m per second and the coating roller being driven at a circumferential speed of about 4to 4.3 m/sec.
3. Procedure in accordance with one of the claims 1 and 2, characterized by the transfer of the coat being effected by the rotary gravure offset printing method.
4. Device for the application of the procedure in accordance with one of the claims 1 through 3, having a rotary driven coating roller (2) and a rotary driven mandrel wheel (1), the mandrels (3) of which are arranged vertically to the wheel plane and are freely rotatable round their longitudinal axis and which are held on the mandrel wheel (1) and are slidable over a portion of the wheel circumference by means of control cams in the direction transverse to their longitudinal axis for adaptation of their path of movement to the circumference of the coating roller which projects into the orbit of the mandrels (3), characterized by a controllable driving device (9) being provided which contacts the mandrels (3) in the zone in front of their deflection from the orbit for adaptation to the circumference of the coating roller to the start of the deflection and again towards the end of the deflection and which makes the mandrels (3) rotate round their longitudinal axis.
5. Device in accordance with claim 4, characterized by the driving device consisting of an endless belt drive (9), the driving strand (9a) of which is tensioned between two drape rolls (11, 12) arranged in front of and behind the deflection zone of the mandrels in the direction of movement of the mandrel wheel and which rests on the mandrels in the zone in front of and at the start as well as towards the end of the deflection from the orbit.
EP81108013A 1980-10-22 1981-10-07 Process and device for varnishing hollow cylindrical bodies all-around, such as can-bodies Expired EP0050269B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3039812A DE3039812C2 (en) 1980-10-22 1980-10-22 Process and device for all-round painting of cylindrical hollow bodies, such as can bodies
DE3039812 1980-10-22

Publications (2)

Publication Number Publication Date
EP0050269A1 EP0050269A1 (en) 1982-04-28
EP0050269B1 true EP0050269B1 (en) 1985-03-20

Family

ID=6114934

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81108013A Expired EP0050269B1 (en) 1980-10-22 1981-10-07 Process and device for varnishing hollow cylindrical bodies all-around, such as can-bodies

Country Status (3)

Country Link
EP (1) EP0050269B1 (en)
DE (2) DE3039812C2 (en)
DK (1) DK149710C (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0076134A2 (en) * 1981-09-28 1983-04-06 B. & H. Manufacturing Company, Inc. Machine for coating plastic containers
EP0134158A2 (en) * 1983-08-22 1985-03-13 Coors Brewing Company Base coat applicator
EP0555730A1 (en) * 1992-02-08 1993-08-18 Herberts Gesellschaft mit beschränkter Haftung Process and apparatus for coating hollow cylindrical bodies
WO2000033973A1 (en) 1998-12-07 2000-06-15 Schmalbach-Lubeca Ag Applying a coating layer onto a thin-walled container

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1536978A1 (en) * 1967-01-03 1970-09-17 Hinterkopf Kurt G Machine for printing, painting, equipping, labeling, etc., of tubular, tubular or tubular workpieces in a continuous flow
DE2121725C3 (en) * 1971-05-03 1979-04-26 Kurt G. 7332 Eislingen Hinterkopf Device for printing or painting hollow bodies, for example tubes
JPS50123741A (en) * 1974-02-04 1975-09-29
US4089294A (en) * 1976-04-08 1978-05-16 Fox Valley Corporation Tube coating apparatus
US4148948A (en) * 1977-05-13 1979-04-10 Textron, Inc. Water dispersible paints of improved leveling characteristics
US4138965A (en) * 1977-11-14 1979-02-13 American Can Company Apparatus for delivering metered amounts of varnish to the surface of a can, or the like

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0076134A2 (en) * 1981-09-28 1983-04-06 B. & H. Manufacturing Company, Inc. Machine for coating plastic containers
EP0076134A3 (en) * 1981-09-28 1984-03-28 B. & H. Manufacturing Company, Inc. Machine for coating plastic containers
EP0134158A2 (en) * 1983-08-22 1985-03-13 Coors Brewing Company Base coat applicator
EP0134158A3 (en) * 1983-08-22 1986-10-15 Adolph Coors Company Base coat applicator
EP0555730A1 (en) * 1992-02-08 1993-08-18 Herberts Gesellschaft mit beschränkter Haftung Process and apparatus for coating hollow cylindrical bodies
WO2000033973A1 (en) 1998-12-07 2000-06-15 Schmalbach-Lubeca Ag Applying a coating layer onto a thin-walled container

Also Published As

Publication number Publication date
DE3039812C2 (en) 1988-12-01
DK149710C (en) 1987-04-06
DK464781A (en) 1982-04-23
DE3039812A1 (en) 1982-05-27
DE3169419D1 (en) 1985-04-25
EP0050269A1 (en) 1982-04-28
DK149710B (en) 1986-09-15

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