EP0423555B1 - Process and apparatus for the electrochemical graining of a metal surface - Google Patents

Process and apparatus for the electrochemical graining of a metal surface Download PDF

Info

Publication number
EP0423555B1
EP0423555B1 EP90119115A EP90119115A EP0423555B1 EP 0423555 B1 EP0423555 B1 EP 0423555B1 EP 90119115 A EP90119115 A EP 90119115A EP 90119115 A EP90119115 A EP 90119115A EP 0423555 B1 EP0423555 B1 EP 0423555B1
Authority
EP
European Patent Office
Prior art keywords
zone
electrolyte
equal
range
chamber
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 - Lifetime
Application number
EP90119115A
Other languages
German (de)
French (fr)
Other versions
EP0423555A1 (en
Inventor
Kurt Hausmann
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.)
Individual
Original Assignee
Individual
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of EP0423555A1 publication Critical patent/EP0423555A1/en
Application granted granted Critical
Publication of EP0423555B1 publication Critical patent/EP0423555B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25F—PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
    • C25F3/00—Electrolytic etching or polishing
    • C25F3/02—Etching
    • C25F3/04—Etching of light metals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
    • B41N3/00—Preparing for use and conserving printing surfaces
    • B41N3/03—Chemical or electrical pretreatment
    • B41N3/034—Chemical or electrical pretreatment characterised by the electrochemical treatment of the aluminum support, e.g. anodisation, electro-graining; Sealing of the anodised layer; Treatment of the anodic layer with inorganic compounds; Colouring of the anodic layer
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S204/00—Chemistry: electrical and wave energy
    • Y10S204/09—Wave forms

Definitions

  • the invention relates to a method for the electrochemical roughening of the surface of preferably band-shaped carrier metal, in particular for printing plates, preferably offset printing plates, in which the carrier metal is preferably introduced after degreasing into an electrolyte bath containing several zones and in the region of each zone of action exposed to alternating current introduced into the electrolyte bath, and according to a further inventive concept goes to a preferred device for carrying out this method.
  • a method and an apparatus of the type mentioned above are known from US Pat. No. 3,755,116.
  • two zones are provided, each of which is assigned a chamber of a trough divided into two chambers by an intermediate wall.
  • the intermediate wall is provided with a passage recess for the band-shaped carrier metal, so that the two chambers communicate with one another and act as a single space.
  • the selection of special roughening parameters such as the selection of a special temperature for each zone and / or the selection of a special electrolyte for each zone, is not possible here.
  • the current density and current frequency inevitably match in both zones.
  • An electrode is assigned to each chamber. However, the electrodes provided are connected to the same current source, so that the same current density and frequency result everywhere. In another case, disruptions would also be feared.
  • Another object of the present invention is to improve a method of the type mentioned at the beginning with simple and inexpensive means in such a way that not only can a uniformly roughened, streak-free and smudge-free surface be produced, but also high economic efficiency is achieved.
  • Another object of the present invention is to provide a device which is suitable and particularly expedient for carrying out the method.
  • the solution relating to the method is that the current frequency is higher in the first zone and the current density is at least not less than in the second zone, in which a longer dwell time is maintained than in the first zone, and that a third zone is provided in which the current frequency is greatest.
  • the comparatively high frequency in the area of the first stage leads to a comparatively large number of points of attack in the area of surface to be roughened, ie small depressions begin to form at comparatively many places on this surface.
  • the particularly high frequency that is subsequently used in the area of the third stage primarily eliminates the smut that has meanwhile settled in the area of the depressions.
  • the current density in the region of the first zone can also advantageously be greater than in the region of the second zone. Due to the correspondingly high current density in the area of the first zone, the attack on the surface to be roughened, which occurs here in many places, is particularly intense.
  • a further advantageous measure can consist in the fact that the current density in the region of the third zone lies in the region between the current densities of the first and the second zone. This ensures that there is no significant change in the roughness in the area of the third zone and that there is primarily removal of smut. Accordingly, a comparatively short dwell time is sufficient in the area of the third zone.
  • the residence time in the region of the third zone can expediently lie in the region between the residence times in the region of the first and the second zone. This is sufficient to remove smut.
  • a further expedient measure can consist in the fact that the highest electrolyte temperature is present at least in the area of the first zone. This can also intensify the attack on the surface to be roughened, which occurs in many places. Accordingly, the electrolyte temperature in the region of the first zone can advantageously be higher than in the other two zones, the electrolyte temperature in the region of the third zone expediently in the region between the electrolyte temperatures the first and second zones.
  • electrolytes can be used in the area of the three zones. This enables individual adaptation to the needs of the individual case. Nevertheless, at least one identical component can be contained in the electrolyte of each stage to achieve good economy, preferably in the form of HCl, preferably in the concentration of 5 g / l.
  • the device-related solution to the problem can be based on a device with at least one roughening station, which contains a plurality of chambers, each of which can be charged with heatable, electrolytic liquid, into which at least one electrode can be connected to a power source, and with transport devices, preferably formed by transport rollers, for Transport of the preferably strip-shaped carrier metal past the electrodes consists, according to the invention, in that the chambers of a roughening station do not communicate with one another and that each chamber is assigned its own electrolyte source and its own, preferably adjustable heating device, as well as a power supply device with individually predeterminable current density and current frequency.
  • the path of this band-shaped carrier metal through the chambers can advantageously be of different lengths in accordance with the difference in the desired throughput times.
  • the chambers can simply have a different, clear length. In this way, the desired throughput times can be achieved in a simple manner despite the constant belt speed.
  • a strip-shaped carrier metal for example made of Al 1050 or Al 3003, is assumed, the surface of which is first roughened, then coated with an oxide layer and then treated with a so-called interlayer before a photosensitive one Layer applied becomes.
  • the device on which the drawing is based contains a roughening station designated as a whole by 1. This has a trough-shaped container 2, which is divided into two chambers 4, 5, 6 by two partitions 3. In and outside the chambers 4, 5, 6 guide elements formed by deflection rollers 7 are provided, via which the band 9 unwound from a roller 8 is guided and which are arranged such that the band 9 in the form of U-shaped loops through each chamber 4 , 5, 6 is passed. Some of the deflection rollers 7 can be driven to accomplish a belt transport. In many cases, however, the tension exerted on the tape in the region of a winding station (not shown here) is sufficient.
  • the belt 9 Before the belt 9 enters the roughening station 1, it is degreased and then rinsed.
  • the unwinding station receiving the roll 8 is followed by a degreasing basin 10 to which sodium hydroxide solution or the like can be applied, through which the belt 9 is passed in the form of a U-shaped loop.
  • pre-etching takes place at the same time.
  • the belt 9 passes through a rinsing station 12 which is provided with spray nozzles 11 on both sides of the transport plane and can be acted upon by rinsing water.
  • the belt pretreated in this way runs into the roughening station 1, in which roughening is accomplished electrochemically.
  • the roughening station 1 and accordingly also the processing taking place here are in three zones I, corresponding to the number of successive chambers 4, 5, 6, II, III divided, each of which a chamber 4, 5, 6 is assigned.
  • the chambers 4, 5, 6 each contain a filling of an electrolytic liquid. This consists essentially of water, to which certain agents have been added.
  • the agents added can consist of one or more components.
  • HCl is to be found in all three zones and everywhere in the concentration of 5 g / l.
  • Zone I there are no other agents apart from HCl.
  • zone II there is also H3BO3 in addition to HCl in the concentration of 10g / l.
  • zone III there is also H3BO3 in addition to HCl, here in the concentration of 1g / l.
  • H3BO3 in addition to HCl, here in the concentration of 1g / l.
  • other reagents could also be used.
  • hydrochloric acid instead of hydrochloric acid, nitric acid could also be used and the like. The same applies to further electrolyte compositions which can be found in the prior art.
  • each chamber 4, 5, 6 should be acted upon by an electrolyte of a special composition, each chamber 4, 5, 6 is assigned its own electrolyte storage container 14, 15, 16, one of which leads to the assigned chamber 4, 5, 6, with a pump 17 provided supply line 18 goes out.
  • the chambers 4, 5, 6 are acted upon by the associated electrolyte during continuous operation. Accordingly, from each chamber 4, 5, 6 a return line 19 connected to an overflow leads back to the associated storage container 14, 15, 16.
  • each chamber has its own heating device 20 assigned, which can be controlled by means of an associated control device 21.
  • the heating device can be a flow heater arranged in the supply line 18.
  • the heating device 20 is designed in the form of a heating coil arranged in the respectively assigned chamber 4, 5, 6. In the exemplary embodiment shown, this should be electrically heatable and is accordingly connected to the electrical network 22.
  • the controller of the control device 21 is adjustable, as indicated by the scale 23.
  • control devices 21 are to be set so that the electrolyte temperature in the chamber 4 belonging to zone I is 36 ° C., in the chamber 5 belonging to zone II 28 ° C. and in the chamber 6 belonging to zone III 6 31 ° C. .
  • the electrolyte temperature of zone I can be between 30 ° C and 40 ° C, zone II between 20 ° C and 40 ° C and zone III between 25 ° C and 35 ° C. Within these ranges, the temperatures are in any case chosen so that the highest electrolyte temperature is present in zone I and the lowest electrolyte temperature in zone II and the electrolyte temperature of zone III is in between.
  • each chamber 4, 5, 6. can be blocks made of graphite and spaced next to one another, on the underside of which the strip 9 is guided. In such a case, only the upper side of the tape facing the electrodes 24 is roughened, which is desirable in the production of printing plates is. If both sides of the strip are to be roughened, opposing electrodes can be provided, between which the strip is passed, or electrodes provided with corresponding drive-through windows can be used.
  • the electrodes 24 are supplied with alternating current via the power network 22.
  • each electrode set 24 is assigned its own frequency setting device 25 constructed in the manner of a frequency amplifier and its own current or voltage setting device 26 constructed in the manner of a current or voltage amplifier, which are adjustable, as indicated by the scale 27 or 28 .
  • the frequency setting devices 25 should be set so that a current frequency of 210 Hz is present in zone I, 45 Hz in zone II and 315 Hz in zone III.
  • the frequency in Zone I can be between 120Hz to 240Hz, in Zone II between 20Hz to 80Hz and in Zone III between 250Hz to 360Hz. Within these ranges, the frequency is always chosen so that the frequency in zone I is much higher than in zone II, but remains lower than in zone III, in which the greatest frequency is used.
  • the current or voltage setting devices 26 are set here so that there is a current density of 50A / dm2 in the area of Zone I, 20A / dm2 in Zone II and 30A / dm2 in Zone III.
  • the current density in zone I can be between 40A / dm2 to 80A / dm2, in zone II between 10A / dm2 to 30A / dm2 and in zone III between 15A / dm2 to 50A / dm2. Within these areas the current density is always chosen so that the greatest current density is present in the region of the first zone I and the lowest current density is present in the region of the second zone II, and that the current density lies in the region of zone III in between.
  • the belt 9 should move at a constant speed here.
  • the passage paths of the belt 9 through the zones I, II, III are accordingly chosen so that the desired dwell times result. Different residence times are desirable in the present case.
  • the chambers 4, 5, 6 assigned to the zones I, II, III accordingly have different clear widths depending on the desired dwell time in the running direction of the belt.
  • the longest dwell time is desired in zone II. Accordingly, the chamber 5 assigned to zone II has the greatest length.
  • the shortest dwell time is desired in zone I. Accordingly, the chamber 4 assigned to zone I has the smallest length.
  • the length of the chamber 6 is between the lengths of the chambers 4 and 5.
  • the chamber lengths are dimensioned so that there is a dwell time of 3 seconds in the chamber 4 belonging to zone I and a dwell time of 10 seconds in zone 5 belonging to zone II . and in the chamber 6 belonging to zone III a dwell time of 4 seconds. results.
  • the dwell time can be varied by changing the belt speed.
  • the usable range for chamber 4 belonging to zone I is 2 seconds. to 5sec., for chamber 5 belonging to Zone II between 6sec. up to 15sec. and for the chamber 6 belonging to zone III between 2sec. up to 6s ..
  • the current density in zone I was 50A / dm2, the current frequency was 210Hz and the dwell time was 3 seconds. and the temperature 36 ° C.
  • the liquid contained the component HCl in a concentration of 5 g / l.
  • the current density was also 50A / dm2, the frequency 45Hz, the dwell time 10sec. and the electrolyte temperature is 28 ° C.
  • the liquid contained the component HCl in a concentration of 5 g / l and the component H 3 BO 3 in a concentration of 10 g / l.
  • the current density was again in zone III 50A / dm2, the current frequency 315Hz, the dwell time 4sec.
  • the electrolyte temperature is 31 ° C.
  • the liquid contained the components HCl in a concentration of 5g / l and H3BO3 in a concentration of 1g / l.
  • the tape processed in this way had a very uniform, practically white, streak- and smut-free surface.
  • the belt 9 After leaving the roughening station 1, the belt 9 passes through a rinsing station 29 which is arranged downstream of the roughening station 1 and which is provided with spray nozzles 30 which are arranged on both sides of the transport plane and can be acted upon by water.
  • the tape 9 prepared in this way can then be fed to an anodizing device, which is no longer shown here, in which the roughened surface is coated with an oxide layer.
  • the tape can then pass through an application station for applying a so-called interlayer.
  • the roughened tape which is provided with an oxide layer and an interlayer layer, forms the base material for the production of printing plates. For this purpose, the tape is cut into pieces and coated with a photosensitive layer before or after.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Printing Plates And Materials Therefor (AREA)

Description

Die Erfindung betrifft gemäß einem ersten Erfindungsgedanken ein Verfahren zur elektrochemischen Aufrauhung der Oberfläche von vorzugsweise bandförmigem Trägermetall, insbesondere für Druckplatten, vorzugsweise Offset-Druckplatten, bei dem das Trägermetall vorzugsweise nach einer Entfettung in ein mehrere Zonen enthaltendes Elektrolytbad eingebracht und im Bereich jeder Zone der Wirkung von in das Elektrolytbad eingeleitetem Wechselstrom ausgesetzt wird, und geht gemäß einem weiteren Erfindungsgedanken auf eine bevorzugte Vorrichtung zur Durchführung dieses Verfahrens.According to a first idea of the invention, the invention relates to a method for the electrochemical roughening of the surface of preferably band-shaped carrier metal, in particular for printing plates, preferably offset printing plates, in which the carrier metal is preferably introduced after degreasing into an electrolyte bath containing several zones and in the region of each zone of action exposed to alternating current introduced into the electrolyte bath, and according to a further inventive concept goes to a preferred device for carrying out this method.

Aus der US-A 3 755 116 sind ein Verfahren und eine Vorrichtung obenerwähnter Art bekannt. Bei dieser bekannten Lösung sind zwar zwei Zonen vorgesehen, denen jeweils eine Kammer einer durch eine Zwischenwand in zwei Kammern unterteilten Wanne zugeordnet ist. Die Zwischenwand ist jedoch mit einer Durchtrittsausnehmung für das bandförmige Trägermetall versehen, so daß die beiden Kammern miteinander kommunizieren und wie ein einheitlicher Raum fungieren. Die Wahl spezieller Aufrauhparameter, wie beispielsweise die Wahl einer speziellen Temperatur für jede Zone und/oder die Wahl eines speziellen Elektrolyts für jede Zone, ist hierbei nicht möglich. Auch die Stromdichte und Stromfrequenz stimmen zwangsläufig in beiden Zonen überein. Es ist zwar jeder Kammer eine Elektrode zugeordnet. Die vorgesehenen Elektroden liegen jedoch an derselben Stromquelle, so daß sich überall dieselbe Stromdichte und -frequenz ergeben. In einem anderen Fall wären auch Störungen zu befürchten.A method and an apparatus of the type mentioned above are known from US Pat. No. 3,755,116. In this known solution, two zones are provided, each of which is assigned a chamber of a trough divided into two chambers by an intermediate wall. However, the intermediate wall is provided with a passage recess for the band-shaped carrier metal, so that the two chambers communicate with one another and act as a single space. The selection of special roughening parameters, such as the selection of a special temperature for each zone and / or the selection of a special electrolyte for each zone, is not possible here. The current density and current frequency inevitably match in both zones. An electrode is assigned to each chamber. However, the electrodes provided are connected to the same current source, so that the same current density and frequency result everywhere. In another case, disruptions would also be feared.

Die Erfahrung hat gezeigt, daß hierbei mit vertretbarem Aufwand nur eine sehr ungleichmäßige Rauhigkeit mit vergleichsweise wenig Vertiefungen erreicht wird, die ungleichmäßig über die Oberfläche verteilt sind und die nicht smutfrei sind. Die Folge der ungleichmäßigen Rauhigkeit sind sichtbare Streifen. Bei dem in den Vertiefungen sich niederschlagenden Smut handelt es sich um eine Art Sumpf von aus der Oberfläche herausgelösten, kleinen Teilchen. Es ergibt sich dementsprechend eine schwarze Färbung der Oberfläche, was bei Druckplatten unerwünscht ist, da hierbei beim Druckbetrieb die farbführenden und die nichtfarbführenden Flächen nur sehr schlecht unterscheidbar sind. Bisher ist daher eine Nachbehandlung in Form einer Nachätzung mit anschließender Neutralisation zur Smutbeseitigung erforderlich. Abgesehen davon ist bisher nur im Falle sehr langer Verweilzeiten überhaupt eine Oberflächenrauhigkeit erreichbar, die bei der Herstellung von Druckplatten akzeptabel ist. Es ergeben sich dementsprechend schon aus diesem Grunde ein hoher Energie- und Zeitbedarf, was sich ungünstig auf die Wirtschaftlichkeit auswirkt, von dem zusätzlichen Aufwand zur Smutbeseitigung ganz abgesehen.Experience has shown that with reasonable effort only a very uneven roughness with comparatively few depressions is achieved, which are distributed unevenly over the surface and which are not smut-free. The result of the uneven roughness is visible streaks. The smut that is deposited in the depressions is a kind of swamp of small particles that have been removed from the surface. Accordingly, there is a black coloring of the surface, which is undesirable in the case of printing plates, since it is very difficult to distinguish between the ink-guiding and the non-ink-guiding surfaces during printing. So far, therefore Post-treatment in the form of an etching with subsequent neutralization is necessary to remove smut. Apart from that, a surface roughness that is acceptable in the manufacture of printing plates has only been achievable in the case of very long dwell times. Accordingly, there is a high energy and time requirement for this reason alone, which has an unfavorable effect on the economy, not to mention the additional effort for eliminating smut.

Hiervon ausgehend ist es die Aufgabe der vorliegenden Erfindung, ein Verfahren eingangs erwähnter Art mit einfachen und kostengünstigen Mitteln so zu verbessern, daß nicht nur eine gleichmäßig aufgerauhte, streifen- und smutfreie Oberfläche erzeugt werden kann, sondern auch eine hohe Wirtschaftlichkeit erreicht wird. Eine weitere Aufgabe der vorliegenden Erfindung besteht darin, eine zur Durchführung des Verfahrens geeignete und besonders zweckmäßige Vorrichtung bereitzustellen.Proceeding from this, it is the object of the present invention to improve a method of the type mentioned at the beginning with simple and inexpensive means in such a way that not only can a uniformly roughened, streak-free and smudge-free surface be produced, but also high economic efficiency is achieved. Another object of the present invention is to provide a device which is suitable and particularly expedient for carrying out the method.

Die auf das Verfahren sich beziehende Lösung besteht erfindungsgemäß darin, daß die Stromfrequenz in der ersten Zone größer und die Stromdichte zumindest nicht kleiner als in der zweiten Zone sind, in welcher eine längere Verweilzeit eingehalten wird als in der ersten Zone, und daß eine dritte Zone vorgesehen ist, in welcher die Stromfrequenz am größten ist.According to the invention, the solution relating to the method is that the current frequency is higher in the first zone and the current density is at least not less than in the second zone, in which a longer dwell time is maintained than in the first zone, and that a third zone is provided in which the current frequency is greatest.

Mit diesen Maßnahmen wird die gestellte Aufgabe in einfacher und kostengünstiger Weise gelöst. Die vergleichsweise hohe Frequenz im Bereich der ersten Stufe führt zu vergleichsweise vielen Angriffspunkten im Bereich der aufzurauhenden Oberfläche, d. h. an vergleichsweise vielen Stellen dieser Oberfläche beginnen sich kleine Vertiefungen zu bilden. Diese bleiben infolge der vergleichsweise kleinen Verweilzeit in der ersten Stufe jedoch vergleichsweise klein und werden erst im Bereich der zweiten Stufe infolge der dort vorgesehenen langen Verweilzeit stark vergrößert. Infolge der dort vorgesehenen, niedereren Frequenz ergibt sich jedoch keine nennenswerte Änderung der Verteilung mehr. Die anschließend im Bereich der dritten Stufe noch zur Anwendung kommende, besonders hohe Frequenz bewirkt in erster Linie die Beseitigung des zwischenzeitlich im Bereich der Vertiefungen sich abgesetzten Smuts. Insgesamt ergibt sich dementsprechend eine streifen- und smutfreie Oberfläche mit vielen, gleichmäßig verteilten, vergleichsweise tiefen Vertiefungen und dementsprechend mit einer auch für hohe Ansprüche ausreichenden Rauhtiefe mit gleichmäßiger Rauhigkeitsverteilung. Versuche haben gezeigt, daß auch bei Verwendung von schwierigen Materialien, wie beispielsweise Al 3003, die bisher nur auf mechanischem Wege aufgerauht werden konnten, innerhalb einer vergleichsweise geringen Gesamtbearbeitungszeit eine praktisch weiße, streifen- und smutfreie Oberfläche mit guter Rauhigkeit erreicht wird, was gegenüber dem Stand der Technik nicht nur eine Qualitätsverbesserung, sondern auch eine Zeit- und Energieersparnis bringt. Ein weiterer Vorteil der erfindungsgemäßen Maßnahmen ist darin zu sehen, daß infolge der erzielbaren Smutfreiheit jede Art von Nachbearbeitung in Form von Nachätzung und anschließender Neutralisierung und Spülung entfällt. Die Erfindung ergibt daher auch eine ausgezeichnete Gesamtwirtschaftlichkeit.With these measures, the task is solved in a simple and inexpensive manner. The comparatively high frequency in the area of the first stage leads to a comparatively large number of points of attack in the area of surface to be roughened, ie small depressions begin to form at comparatively many places on this surface. However, due to the comparatively short dwell time in the first stage, these remain comparatively small and are only greatly increased in the area of the second stage as a result of the long dwell time provided there. As a result of the lower frequency provided there, there is no longer any significant change in the distribution. The particularly high frequency that is subsequently used in the area of the third stage primarily eliminates the smut that has meanwhile settled in the area of the depressions. Overall, this results in a streak-free and smut-free surface with many, evenly distributed, comparatively deep depressions and accordingly with a roughness depth that is also sufficient for high demands and has a uniform roughness distribution. Experiments have shown that even when using difficult materials, such as Al 3003, which could previously only be roughened mechanically, a practically white, streak-free and smudge-free surface with good roughness is achieved within a comparatively short total processing time, which is compared to the State of the art not only brings quality improvement, but also saves time and energy. Another advantage of the measures according to the invention can be seen in the fact that, owing to the achievable smut freedom, any type of post-processing in the form of post-etching and subsequent neutralization and rinsing is eliminated. The invention therefore also results in excellent overall economy.

Mit Vorteil kann die Stromdichte im Bereich der ersten Zone ebenfalls größer als im Bereich der zweiten Zone sein. Aufgrund der dementsprechend zur Anwendung kommenden, vergleichsweise hohen Stromdichte im Bereich der ersten Zone ist der hier an vielen Stellen stattfindende Angriff auf die aufzurauhende Oberfläche besonders intensiv.The current density in the region of the first zone can also advantageously be greater than in the region of the second zone. Due to the correspondingly high current density in the area of the first zone, the attack on the surface to be roughened, which occurs here in many places, is particularly intense.

Eine weitere vorteilhafte Maßnahme kann darin bestehen, daß die Stromdichte im Bereich der dritten Zone im Bereich zwischen den Stromdichten der ersten und der zweiten Zone liegt. Hierdurch wird sichergestellt, daß im Bereich der dritten Zone keine nennenswerte Veränderung der Rauhigkeit mehr stattfindet und es in erster Linie zur Beseitigung von Smut kommt. Dementsprechend reicht im Bereich der dritten Zone auch eine vergleichsweise kurze Verweilzeit aus.A further advantageous measure can consist in the fact that the current density in the region of the third zone lies in the region between the current densities of the first and the second zone. This ensures that there is no significant change in the roughness in the area of the third zone and that there is primarily removal of smut. Accordingly, a comparatively short dwell time is sufficient in the area of the third zone.

Zweckmäßig kann die Verweilzeit im Bereich der dritten Zone im Bereich zwischen den Verweilzeiten im Bereich der ersten und der zweiten Zone liegen. Dies reicht zur Smutbeseitigung vollständig aus.The residence time in the region of the third zone can expediently lie in the region between the residence times in the region of the first and the second zone. This is sufficient to remove smut.

Eine weitere zweckmäßige Maßnahme kann darin bestehen, daß zumindest im Bereich der ersten Zone die höchste Elektrolyttemperatur vorliegt. Auch hierdurch kann der an vielen Stellen erfolgende Angriff auf die aufzurauhende Oberfläche intensiviert werden. Dementsprechend kann die Elektrolyttemperatur im Bereich der ersten Zone mit Vorteil größer als in den beiden anderen Zonen sein, wobei die Elektrolyttemperatur im Bereich der dritten Zone zweckmäßig im Bereich zwischen den Elektrolyttemperaturen der ersten und zweiten Zone liegen kann.A further expedient measure can consist in the fact that the highest electrolyte temperature is present at least in the area of the first zone. This can also intensify the attack on the surface to be roughened, which occurs in many places. Accordingly, the electrolyte temperature in the region of the first zone can advantageously be higher than in the other two zones, the electrolyte temperature in the region of the third zone expediently in the region between the electrolyte temperatures the first and second zones.

In weiterer Fortbildung der übergeordneten Maßnahmen können im Bereich der drei Zonen jeweils unterschiedliche Elektrolyte Verwendung finden. Dies ermöglicht eine individuelle Anpassung an die Bedürfnisse des Einzelfalls. Dennoch kann im Elektrolyt jeder Stufe zur Erzielung einer guten Wirtschaftlichkeit mindestens eine gleiche Komponente enthalten sein, vorzugsweise in Form von HCl, vorzugsweise in der Konzentration von 5g/l.In a further development of the higher-level measures, different electrolytes can be used in the area of the three zones. This enables individual adaptation to the needs of the individual case. Nevertheless, at least one identical component can be contained in the electrolyte of each stage to achieve good economy, preferably in the form of HCl, preferably in the concentration of 5 g / l.

Weitere vorteilhafte Ausgestaltungen und zweckmäßige Fortbildungen des übergeordneten Verfahrens ergeben sich aus den restlichen Verfahrens-Unteransprüchen.Further advantageous refinements and expedient further developments of the superordinate method result from the remaining method subclaims.

Die vorrichtungsmäßige Lösung der Aufgabe kann ausgehend von einer Vorrichtung mit wenigstens einer Aufrauhstation, die mehrere Kammern enthält, die jeweils mit beheizbarer, elektrolytischer Flüssigkeit beaufschlagbar sind, in die jeweils wenigstens eine an eine Stromquelle anschließbare Elektrode eintaucht, und mit vorzugsweise durch Transportrollen gebildeten Transporteinrichtungen zum an den Elektroden vorbeilaufenden Transport des vorzugsweise bandförmigen Trägermetalls, erfindungsgemäß darin bestehen, daß die Kammern einer Aufrauhstation nicht miteinander kommunizieren und daß jeder Kammer eine eigene Elektrolytquelle und eine eigene, vorzugsweise einstellbare Heizeinrichtung sowie eine Stromversorgungseinrichtung mit individuell vorgebbarer Stromdichte und Stromfrequenz zugeordnet sind.The device-related solution to the problem can be based on a device with at least one roughening station, which contains a plurality of chambers, each of which can be charged with heatable, electrolytic liquid, into which at least one electrode can be connected to a power source, and with transport devices, preferably formed by transport rollers, for Transport of the preferably strip-shaped carrier metal past the electrodes consists, according to the invention, in that the chambers of a roughening station do not communicate with one another and that each chamber is assigned its own electrolyte source and its own, preferably adjustable heating device, as well as a power supply device with individually predeterminable current density and current frequency.

Diese Maßnahmen stellen sicher, daß im Bereich jeder Zone die Stromdichte, die Stromfrequenz, die Elektrolyttemperatur und die Art des zur Anwendung kommenden Elektrolyten individuell vorgegeben werden können, ohne daß gegenseitige Störungen zu befürchten wären.These measures ensure that the current density, the current frequency, the electrolyte temperature and the type of electrolyte used can be specified individually in the area of each zone, without fear of mutual interference.

Vorteilhaft kann dabei im Falle eines bandförmigen Trägermetalls der Weg dieses bandförmigen Trägermetalls durch die Kammern entsprechend dem Unterschied der gewünschten Durchlaufzeiten unterschiedlich lang sein. Hierzu können die Kammern einfach eine unterschiedliche, lichte Länge aufweisen. Hierdurch lassen sich auf einfache Weise trotz konstanter Bandgeschwindigkeit die gewünschten Durchlaufzeiten erreichen.In the case of a band-shaped carrier metal, the path of this band-shaped carrier metal through the chambers can advantageously be of different lengths in accordance with the difference in the desired throughput times. For this purpose, the chambers can simply have a different, clear length. In this way, the desired throughput times can be achieved in a simple manner despite the constant belt speed.

Weitere vorteilhafte Ausgestaltungen und zweckmäßige Fortbildungen der übergeordneten Vorrichtung ergeben sich aus den restlichen Vorrichtungs-Unteransprüchen.Further advantageous refinements and expedient further developments of the higher-level device result from the remaining device subclaims.

Nachstehend wird die Erfindung rein beispielsweise anhand der Zeichnung näher erläutert.The invention is explained in more detail below, for example, with reference to the drawing.

Die einzige Figur der Zeichnung zeigt eine schematische Darstellung einer Vorrichtung zur Durchführung des erfindungsgemäßen Aufrauhverfahrens.The only figure in the drawing shows a schematic representation of a device for carrying out the roughening method according to the invention.

Bei der Herstellung von Offset-Druckplatten oder dergleichen geht man von einem bandförmigen Trägermetall, etwa aus Al 1050 oder Al 3003, aus, dessen Oberfläche zunächst aufgerauht, dann mit einer Oxyd-Schicht überzogen und anschließend mit einem sogenannten Interlayer behandelt wird, bevor eine fotoempfindliche Schicht aufgebracht wird. Die der Zeichnung zugrundeliegende Vorrichtung enthält eine als Ganzes mit 1 bezeichnete Aufrauhstation. Diese besitzt einen wannenförmigen Behälter 2, der durch zwei Zwischenwände 3 in drei Kammern 4, 5, 6 unterteilt ist. In und außerhalb der Kammern 4, 5, 6 sind durch Umlenkrollen 7 gebildete Führungselemente vorgesehen, über welche das von einer Rolle 8 abgewickelte Band 9 geführt wird und die so angeordnet sind, daß das Band 9 in Form U-förmiger Schleifen durch jede Kammer 4, 5, 6 hindurchgeführt wird. Einige der Umlenkrollen 7 können zur Bewerkstelligung eines Bandtransports angetrieben sein. Vielfach genügt hierzu aber auch der im Bereich einer hier nicht näher dargestellten Aufwickelstation auf das Band ausgeübte Zug.In the production of offset printing plates or the like, a strip-shaped carrier metal, for example made of Al 1050 or Al 3003, is assumed, the surface of which is first roughened, then coated with an oxide layer and then treated with a so-called interlayer before a photosensitive one Layer applied becomes. The device on which the drawing is based contains a roughening station designated as a whole by 1. This has a trough-shaped container 2, which is divided into two chambers 4, 5, 6 by two partitions 3. In and outside the chambers 4, 5, 6 guide elements formed by deflection rollers 7 are provided, via which the band 9 unwound from a roller 8 is guided and which are arranged such that the band 9 in the form of U-shaped loops through each chamber 4 , 5, 6 is passed. Some of the deflection rollers 7 can be driven to accomplish a belt transport. In many cases, however, the tension exerted on the tape in the region of a winding station (not shown here) is sufficient.

Bevor das Band 9 in die Aufrauhstation 1 einläuft, wird es entfettet und anschließend gespült. Hierzu ist der die Rolle 8 aufnehmenden Abwickelstation ein mit Natronlauge oder dergleichen beaufschlagbares Entfettungsbassin 10 nachgeordnet, durch welches das Band 9 in Form einer U-förmigen Schleife hindurchgeführt wird. Neben der Entfettung findet hierbei gleichzeitig eine Vorätzung statt. Anschließend durchläuft das Band 9 eine mit beidseitig der Transportebene angeordneten, mit Spülwasser beaufschlagbaren Sprühdüsen 11 versehene Spülstation 12. Das so vorbehandelte Band läuft in die Aufrauhstation 1 ein, in welcher eine Aufrauhung auf elektrochemischem Wege bewerkstelligt wird.Before the belt 9 enters the roughening station 1, it is degreased and then rinsed. For this purpose, the unwinding station receiving the roll 8 is followed by a degreasing basin 10 to which sodium hydroxide solution or the like can be applied, through which the belt 9 is passed in the form of a U-shaped loop. In addition to degreasing, pre-etching takes place at the same time. Subsequently, the belt 9 passes through a rinsing station 12 which is provided with spray nozzles 11 on both sides of the transport plane and can be acted upon by rinsing water. The belt pretreated in this way runs into the roughening station 1, in which roughening is accomplished electrochemically.

Die Aufrauhstation 1 und dementsprechend auch die hier ablaufende Bearbeitung sind entsprechend der Anzahl der aufeinanderfolgenden Kammern 4, 5, 6 in drei Zonen I, II, III unterteilt, denen jeweils eine Kammer 4, 5, 6 zugeordnet ist. Die Kammern 4, 5, 6 enthalten jeweils eine Füllung einer elektrolytischen Flüssigkeit. Diese besteht im wesentlichen aus Wasser, dem gewisse Agenzien beigegeben sind. Die beigegebenen Agenzien können aus einer oder mehreren Komponenten bestehen. Im vorliegenden Fall soll HCl in sämtlichen drei Zonen vorkommen und zwar überall in der Kontentration von 5g/l. In der Zone I sind außer HCl keine weiteren Agenzien vorhanden. In der Zone II ist neben HCl auch noch H₃BO₃ in der Konzentration von 10g/l vorhanden. In der Zone III ist neben HCl ebenfalls H₃BO₃, hier in der Konzentration von 1g/l, vorhanden. Selbstverständlich könnten auch andere Reagenzien Verwendung finden. So könnte anstelle von Salzsäure auch Salpetersäure Verwendung finden und dergleichen. Dasselbe gilt für weitere, aus dem Stand der Technik entnehmbare Elektrolytzusammensetzungen.The roughening station 1 and accordingly also the processing taking place here are in three zones I, corresponding to the number of successive chambers 4, 5, 6, II, III divided, each of which a chamber 4, 5, 6 is assigned. The chambers 4, 5, 6 each contain a filling of an electrolytic liquid. This consists essentially of water, to which certain agents have been added. The agents added can consist of one or more components. In the present case, HCl is to be found in all three zones and everywhere in the concentration of 5 g / l. In Zone I there are no other agents apart from HCl. In zone II there is also H₃BO₃ in addition to HCl in the concentration of 10g / l. In zone III there is also H₃BO₃ in addition to HCl, here in the concentration of 1g / l. Of course, other reagents could also be used. Thus, instead of hydrochloric acid, nitric acid could also be used and the like. The same applies to further electrolyte compositions which can be found in the prior art.

Da jede Kammer 4, 5, 6 mit einem Elektrolyten spezieller Zusammensetzung beaufschlagbar sein soll , ist jeder Kammer 4, 5, 6 ein eigener Elektrolyt-Vorratsbehälter 14, 15, 16 zugeordnet, von dem eine zur zugeordneten Kammer 4, 5, 6 führende, mit einer Pumpe 17 versehene Versorgungsleitung 18 abgeht. Im dargestellten Ausführungsbeispiel werden die Kammern 4, 5, 6 im Durchlaufbetrieb mit dem zugeordneten Elektrolyten beaufschlagt. Dementsprechend führt von jeder Kammer 4, 5, 6 eine an einen überlauf angeschlossene Rücklaufleitung 19 zum zugeordneten Vorratsbehälter 14, 15, 16 zurück.Since each chamber 4, 5, 6 should be acted upon by an electrolyte of a special composition, each chamber 4, 5, 6 is assigned its own electrolyte storage container 14, 15, 16, one of which leads to the assigned chamber 4, 5, 6, with a pump 17 provided supply line 18 goes out. In the exemplary embodiment shown, the chambers 4, 5, 6 are acted upon by the associated electrolyte during continuous operation. Accordingly, from each chamber 4, 5, 6 a return line 19 connected to an overflow leads back to the associated storage container 14, 15, 16.

Um in jeder Kammer 4, 5, 6 die gewünschte Temperatur einhalten zu können, ist jeder Kammer eine eigene Heizeinrichtung 20 zugeordnet, die mittels einer zugehörigen Steuereinrichtung 21 steuerbar ist. Bei der Heizeinrichtung kann es sich um einen in der Versorgungsleitung 18 angeordneten Durchlauferhitzer handeln. Im dargestellten Ausführungsbeispiel ist die Heizeinrichtung 20 in Form einer in der jeweils zugeordneten Kammer 4, 5, 6 angeordneten Heizschlange ausgebildet. Diese soll im dargestellten Ausführungsbeispiel elektrisch beheizbar sein und ist dementsprechend an das elektrische Netz 22 angeschlossen. Der Regler der Steuereinrichtung 21 ist einstellbar, wie durch die Skala 23 angedeutet ist.In order to be able to maintain the desired temperature in each chamber 4, 5, 6, each chamber has its own heating device 20 assigned, which can be controlled by means of an associated control device 21. The heating device can be a flow heater arranged in the supply line 18. In the exemplary embodiment shown, the heating device 20 is designed in the form of a heating coil arranged in the respectively assigned chamber 4, 5, 6. In the exemplary embodiment shown, this should be electrically heatable and is accordingly connected to the electrical network 22. The controller of the control device 21 is adjustable, as indicated by the scale 23.

Die Steuereinrichtungen 21 sollen im vorliegenden Fall so eingestellt werden, daß die Elektrolyttemperatur in der zur Zone I gehörenden Kammer 4 36°C, in der zur Zone II gehörenden Kammer 5 28°C und in der zur Zone III gehörenden Kammer 6 31°C beträgt. Die Elektrolyttemperatur der Zone I kann zwischen 30°C und 40°C, der Zone II zwischen 20°C und 40°C und der Zone III zwischen 25°C und 35°C liegen. Innerhalb dieser Bereiche werden die Temperaturen in jedem Falle so gewählt, daß in der Zone I die höchste Elektrolyttemperatur und in der Zone II die niedrigste Elektrolyttemperatur vorliegen und die Elektrolyttemperatur der Zone III sich dazwischen befindet.In the present case, the control devices 21 are to be set so that the electrolyte temperature in the chamber 4 belonging to zone I is 36 ° C., in the chamber 5 belonging to zone II 28 ° C. and in the chamber 6 belonging to zone III 6 31 ° C. . The electrolyte temperature of zone I can be between 30 ° C and 40 ° C, zone II between 20 ° C and 40 ° C and zone III between 25 ° C and 35 ° C. Within these ranges, the temperatures are in any case chosen so that the highest electrolyte temperature is present in zone I and the lowest electrolyte temperature in zone II and the electrolyte temperature of zone III is in between.

Zur Einleitung von Strom ist in jeder Kammer 4, 5, 6 ein Satz von zwei in derselben Stromschleife angeordneten Elektroden 24 vorgesehen. Hierbei kann es sich um aus Graphit bestehende, mit Abstand nebeneinander angeordnete Blöcke handeln, an deren Unterseite das Band 9 vorbeigeführt wird. In einem derartigen Fall wird nur die den Elektroden 24 zugewandte Bandoberseite aufgerauht, was bei der Herstellung von Druckplatten erwünscht ist. Sofern beide Bandseiten aufgerauht werden sollen, können einander gegenüberliegende Elektroden vorgesehen sein, zwischen denen das Band hindurchgeführt wird, oder es können mit entsprechenden Durchfahrfenstern versehene Elektroden Verwendung finden. Die Elektroden 24 werden über das Stromnetz 22 mit Wechselstrom versorgt. Jedem Elektrodensatz 24 sind jedoch eine eigene, nach Art eines Frequenzverstärkers aufgebaute Frequenzeinstelleinrichtung 25 und eine eigene, nach Art eines Strom- bzw. Spannungsverstärkers aufgebaute Strom- bzw. Spannungseinstelleinrichtung 26 zugeordnet, die einstellbar sind, wie durch die Skala 27 bzw. 28 angedeutet ist.In order to introduce current, a set of two electrodes 24 arranged in the same current loop is provided in each chamber 4, 5, 6. These can be blocks made of graphite and spaced next to one another, on the underside of which the strip 9 is guided. In such a case, only the upper side of the tape facing the electrodes 24 is roughened, which is desirable in the production of printing plates is. If both sides of the strip are to be roughened, opposing electrodes can be provided, between which the strip is passed, or electrodes provided with corresponding drive-through windows can be used. The electrodes 24 are supplied with alternating current via the power network 22. However, each electrode set 24 is assigned its own frequency setting device 25 constructed in the manner of a frequency amplifier and its own current or voltage setting device 26 constructed in the manner of a current or voltage amplifier, which are adjustable, as indicated by the scale 27 or 28 .

Im vorliegenden Fall sollen die Frequenzeinstelleinrichtungen 25 so eingestellt sein, daß in der Zone I eine Stromfrequenz von 210Hz, in der Zone II von 45Hz und in der Zone III von 315Hz vorliegt. Die Frequenz in der Zone I kann zwischen 120Hz bis 240Hz, in der Zone II zwischen 20Hz bis 80Hz und in der Zone III zwischen 250Hz bis 360Hz betragen. Innerhalb dieser Bereiche wird die Frequenz immer so gewählt, daß die Frequenz in der Zone I viel größer als in der Zone II ist, aber kleiner als in der Zone III bleibt, in welcher die größte Frequenz zur Anwendung kommt. Die Strom- bzw. Spannungseinstelleinrichtungen 26 sind hier so eingestellt, daß sich im Bereich der Zone I eine Stromdichte von 50A/dm², in der Zone II von 20A/dm² und in der Zone III von 30A/dm² ergibt. Die Stromdichte im Bereich der Zone I kann zwischen 40A/dm² bis 80A/dm², im Bereich der Zone II zwischen 10A/dm² bis 30A/dm² und in der Zone III zwischen 15A/dm² bis 50A/dm² betragen. Innerhalb dieser Bereiche wird die Stromdichte immer gewählt, daß im Bereich der ersten Zone I die größe Stromdichte und im Bereich der zweiten Zone II die geringste Stromdichte vorliegt, und daß die Stromdichte im Bereich der Zone III dazwischen liegt.In the present case, the frequency setting devices 25 should be set so that a current frequency of 210 Hz is present in zone I, 45 Hz in zone II and 315 Hz in zone III. The frequency in Zone I can be between 120Hz to 240Hz, in Zone II between 20Hz to 80Hz and in Zone III between 250Hz to 360Hz. Within these ranges, the frequency is always chosen so that the frequency in zone I is much higher than in zone II, but remains lower than in zone III, in which the greatest frequency is used. The current or voltage setting devices 26 are set here so that there is a current density of 50A / dm² in the area of Zone I, 20A / dm² in Zone II and 30A / dm² in Zone III. The current density in zone I can be between 40A / dm² to 80A / dm², in zone II between 10A / dm² to 30A / dm² and in zone III between 15A / dm² to 50A / dm². Within these areas the current density is always chosen so that the greatest current density is present in the region of the first zone I and the lowest current density is present in the region of the second zone II, and that the current density lies in the region of zone III in between.

Das Band 9 soll sich hier mit konstanter Geschwindigkeit bewegen. Die Durchlaufwege des Bands 9 durch die Zonen I, II, III sind dementsprechend so gewählt, daß sich die gewünschten Verweilzeiten ergeben. Im vorliegenden Fall sind unterschiedliche Verweilzeiten erwünscht. Die den Zonen I, II, III zugeordneten Kammern 4, 5, 6 besitzen dementsprechend in Laufrichtung des Bands eine von der gewünschten Verweilzeit abhängige, unterschiedliche lichte Weite. Im Bereich der Zone II ist die längste Verweilzeit erwünscht. Dementsprechend besitzt die der Zone II zugeordnete Kammer 5 die größte Länge. In der Zone I ist die kürzeste Verweilzeit erwünscht. Dementsprechend besitzt die der Zone I zugeordnete Kammer 4 die geringste Länge. Die Länge der Kammer 6 liegt zwischen den Längen der Kammern 4 und 5. Die Kammerlängen sind hier so bemessen, daß sich in der zur Zone I gehörenden Kammer 4 eine Verweilzeit von 3sec., in der zur Zone II gehörenden Zone 5 eine Verweilzeit von 10sec. und in der zur Zone III gehörenden Kammer 6 eine Verweilzeit von 4sec. ergibt. Im Falle unveränderbarer Kammerlängen, wie hier, läßt sich die Verweilzeit durch Änderung der Bandgeschwindigkeit variieren. Der brauchbare Bereich liegt dabei für die zur Zone I gehörende Kammer 4 bei 2sec. bis 5sec., für die zur Zone II gehörende Kammer 5 zwischen 6sec. bis 15sec. und für die zur Zone III gehörende Kammer 6 zwischen 2sec. bis 6sec..The belt 9 should move at a constant speed here. The passage paths of the belt 9 through the zones I, II, III are accordingly chosen so that the desired dwell times result. Different residence times are desirable in the present case. The chambers 4, 5, 6 assigned to the zones I, II, III accordingly have different clear widths depending on the desired dwell time in the running direction of the belt. The longest dwell time is desired in zone II. Accordingly, the chamber 5 assigned to zone II has the greatest length. The shortest dwell time is desired in zone I. Accordingly, the chamber 4 assigned to zone I has the smallest length. The length of the chamber 6 is between the lengths of the chambers 4 and 5. The chamber lengths are dimensioned so that there is a dwell time of 3 seconds in the chamber 4 belonging to zone I and a dwell time of 10 seconds in zone 5 belonging to zone II . and in the chamber 6 belonging to zone III a dwell time of 4 seconds. results. In the case of unchangeable chamber lengths, as here, the dwell time can be varied by changing the belt speed. The usable range for chamber 4 belonging to zone I is 2 seconds. to 5sec., for chamber 5 belonging to Zone II between 6sec. up to 15sec. and for the chamber 6 belonging to zone III between 2sec. up to 6s ..

Bei Beaufschlagung der Elektroden 24 mit Strom kommt ein elektrochemischer Vorgang in Gang, durch den die den Elektroden 24 zugewandte Oberfläche des Bands 9 aufgerauht wird. Die hohe Frequenz und Stromdichte und die kurze Verweilzeit im Bereich der Zone I führt dabei zum Entstehen sehr vieler, und dementsprechend gleichmäßig über die aufzurauhende Oberfläche verteilter, aber noch sehr kleiner Vertiefungen. Diese werden im Bereich der Zone II, in der eine lange Verweilzeit bei vergleichsweise niedrigem Strom- und Frequenzniveau gegeben ist, stark vergrößert. Infolge des niedrigen Strom- und Frequenzniveaus entstehen in der Zone II praktisch keine neuen Vertiefungen mehr, sondern es werden lediglich die in der Zone I erzielten Angriffspunkte erweitert. Ein großer Teil des aus dem Band 9 herausgelösten Materials setzt sich in Form eines Sumpfes, sogenanntem Smut, in den hergestellten Vertiefungen ab. Dieser Smut wird im Bereich der Zone III infolge der hier zur Anwendung kommenden, sehr hohen Stromfrequenz und mittleren Stromdichte, in Bewegung gebracht und praktisch weggewirbelt.When current is applied to the electrodes 24, an electrochemical process starts, by which the surface of the strip 9 facing the electrodes 24 is roughened. The high frequency and current density and the short dwell time in the area of zone I lead to the formation of very many, and accordingly, evenly distributed over the surface to be roughened, but still very small depressions. These are greatly increased in the area of Zone II, in which there is a long dwell time at a comparatively low current and frequency level. As a result of the low current and frequency level, practically no new depressions are created in Zone II, but only the points of attack achieved in Zone I are expanded. A large part of the material released from the band 9 settles in the form of a sump, so-called smut, in the depressions produced. This smut is set in motion in Zone III due to the very high current frequency and medium current density used here and practically whirled away.

Bei Versuchen mit einem aus Al 1050 bestehenden Band betrugen in der Zone I die Stromdichte 50A/dm², die Stromfrequenz 210Hz, die Verweilzeit 3sec. und die Temperatur 36°C. Die Flüssigkeit enthielt neben Wasser die Komponente HCl in einer Konzentration von 5g/l. In der Zone II betrugen die Stromdichte ebenfalls 50A/dm², die Frequenz 45Hz, die Verweilzeit 10sec. und die Elektrolyttemperatur 28°C. Die Flüssigkeit enthielt neben Wasser die Komponente HCl in einer Konzentration von 5g/l und die Komponente H₃BO₃ in einer Konzentration von 10g/l. In der Zone III betrugen die Stromdichte wiederum 50A/dm², die Stromfrequenz 315Hz, die Verweilzeit 4sec. und die Elektrolyttemperatur 31°C. Die Flüssigkeit enthielt neben Wasser die Komponenten HCl in einer Konzentration von 5g/l und H₃BO₃ in einer Konzentration von 1g/l. Das so bearbeitete Band besaß eine sehr gleichmässige, praktisch weiße, streifen- und smutfreie Oberfläche.In experiments with a band consisting of Al 1050, the current density in zone I was 50A / dm², the current frequency was 210Hz and the dwell time was 3 seconds. and the temperature 36 ° C. In addition to water, the liquid contained the component HCl in a concentration of 5 g / l. In Zone II the current density was also 50A / dm², the frequency 45Hz, the dwell time 10sec. and the electrolyte temperature is 28 ° C. In addition to water, the liquid contained the component HCl in a concentration of 5 g / l and the component H 3 BO 3 in a concentration of 10 g / l. The current density was again in zone III 50A / dm², the current frequency 315Hz, the dwell time 4sec. and the electrolyte temperature is 31 ° C. In addition to water, the liquid contained the components HCl in a concentration of 5g / l and H₃BO₃ in a concentration of 1g / l. The tape processed in this way had a very uniform, practically white, streak- and smut-free surface.

Bei einem weiteren Versuch mit einem aus Al 3003 bestehenden Band betrugen die Stromdichten in der Zone 50A/dm² , in der Zone II 20A/dm² und in der Zone III 50A/dm². Ansonsten wurden die beim ersten Versuch vorliegenden Parameter eingehalten. Die aufgerauhte Oberfläche des so bearbeiteten Bands besaß trotz der an sich bekannten, schlechten Aufrauhbarkeit von Al 3003 praktisch dieselbe Beschaffenheit wie das Band im ersten Beispiel, jedoch war die optische Dichte etwas höher.In a further test with a band consisting of Al 3003, the current densities in the zone were 50A / dm², in zone II 20A / dm² and in zone III 50A / dm². Otherwise, the parameters present in the first attempt were observed. The roughened surface of the tape processed in this way had practically the same properties as the tape in the first example, despite the known poor roughening properties of Al 3003, but the optical density was somewhat higher.

Nach dem Verlassen der Aufrauhstation 1 durchläuft das Band 9 eine der Aufrauhstation 1 nachgeordnete Spülstation 29, die mit zu beiden Seiten der Transportebene angeordneten, mit Wasser beaufschlagbaren Sprühdüsen 30 versehen ist. Das so vorbereitete Band 9 kann anschliessend einer hier nicht mehr dargestellten Anodisierungseinrichtung zugeführt werden, in welcher die aufgerauhte Oberfläche mit einer Oxydschicht überzogen wird. Anschließend kann das Band eine Auftragstation zum Auftragen eines sogenannten Interlayers durchlaufen. Das aufgerauhte, mit einer Oxydschicht und einer Interlayerschicht versehene Band bildet das Basismaterial zur Herstellung von Druckplatten. Hierzu wird das Band in Stükke geschnitten und vorher oder nachher mit einer fotoempfindlichen Schicht beschichtet.After leaving the roughening station 1, the belt 9 passes through a rinsing station 29 which is arranged downstream of the roughening station 1 and which is provided with spray nozzles 30 which are arranged on both sides of the transport plane and can be acted upon by water. The tape 9 prepared in this way can then be fed to an anodizing device, which is no longer shown here, in which the roughened surface is coated with an oxide layer. The tape can then pass through an application station for applying a so-called interlayer. The roughened tape, which is provided with an oxide layer and an interlayer layer, forms the base material for the production of printing plates. For this purpose, the tape is cut into pieces and coated with a photosensitive layer before or after.

Claims (15)

  1. A method for the electrochemical roughening of the surface of preferably strip-like substrate material, more particularly for printing plates, and in particular offset printing plate, in the case of which the substrate material preferably after degreasing is placed in an electrolyte bath having a plurality of zones and within each zone is subjected to the action of AC fed to the electrolyte bath, characterized in that the current frequency in the first zone is higher and the current density is at least not lower than in the second zone, in which the residence time is longer than in the first zone and in that a third zone is provided, in which the current frequency is highest.
  2. The method as claimed in claim 1, characterized in that the current density in the first zone is greater than in the second zone and in that preferably the current density in the third zone is in a range between the current densities in the first zone and in the second zone.
  3. The method as claimed in any one of the preceding claims, characterized in that the residence time in the third zone is at least equal to the residence time in the first zone and at the most is equal to the residence time in the second zone and more particularly is between the residence times in the first and in the second zone.
  4. The method as claimed in any one of the preceding claims, characterized in that at least in the first zone the highest electrolyte temperature is maximum and in that preferably the electrolyte temperature in the first zone is higher than in the two other zones and the electrolyte temperature in the third zone is between the electrolyte temperatures in the first zone and in the second zone.
  5. The method as claimed in any one of the preceding claims, characterized in that different electrolytes are utilized in the three zone, the electrolyte in each zone preferably having at least one common component, preferably in the form of HCl and again preferably at a concentration of 5 g/l.
  6. The method as claimed in claim 5, characterized in that apart from the component common to all zones, the electrolyte of the first zone does not comprise any further component, in that apart from the component common to all zones, the electrolyte of the second zone comprises a further component, preferably in the form of H₃BO₃, again preferably at a concentration of 10 g/l and the electrolyte in the third zone apart from the component common to all zones, comprises a further component, preferably in the form of H₃BO₃, at a lower concentration than the second and again preferably at a concentration of 1 g/1.
  7. The method as claimed in any one of the preceding claims, characterized in that the current frequency in the first zone is in a range of between 120 Hz and 240 Hz and preferably is equal to 210 Hz, in that the current frequency in the second zone is in a range between 20 Hz and 80 Hz and preferably is equal to 45 Hz and in that the current frequency in the third zone is in a range between 250 Hz and 360 Hz and preferably is equal to 315 Hz.
  8. The method as claimed in any one of the preceding claims, characterized in that the current density in the first zone is in a range between 40 A/dm² and 80 A/dm² and is preferably equal to 50 A/dm², in that the current density in the second zone is in a range between 10 A/dm² and 30 A/dm², and is preferably equal to 20 A/dm² and in that the current density in the third zone is in a range of between 15 A/dm² and 50 A/dm², and is preferably equal to 30 A/dm².
  9. The method as claimed in any one of the preceding claims, characterized in that the electrolyte temperature in the first zone is in a range between 30° C and 40° C, and preferably is equal to 36° C, in that the electrolyte temperature in the second zone is in a range between 20° C and 40° C, and is preferably equal to 28° C and in that the electrolyte temperature in the third zone is in a range between 20° C and 35° C and is preferably equal to 31° C.
  10. The method as claimed in any one of the preceding claims, characterized in that the residence time in the first zone is in a range between 2 sec. and 5 sec. and is preferably equal to 3 sec., in that the residence time in the second zone is in a range between 6 sec. and 15 sec. and is preferably equal to 10 sec. and in that the residence time in the third zone is in a range between 2 sec. and 6 sec and is preferably equal to 4 sec.
  11. The method as claimed in any one of the preceding claims, characterized in that in the case of the treatment of Al 1050 as a substrate material the current density in all three zones is equal to 50 A/dm² and in that the frequencies, residence times, electrolyte temperatures and types of electrolyte are as preferred.
  12. The method as claimed in any one of the preceding claims, characterized in that in the case of the treatment of Al 3003 as the substrate material the current density in the first and in the third zones is equal to 50 A/dm² and in the second zone is equal to 20 A/dm² and in that the frequencies, residence times, electrolyte temperatures and types of electrolyte are as preferred.
  13. An apparatus for the performance of the method comprising at least one roughening station (1), which comprises a plurality of chambers (4, 5 and 6), which are respectively able to be fed with a heatable electrolyte liquid, into which there respectively dips at least one electrode (24) able to be connected with a source of current, and more particularly a set of two electrodes (24), and conveying means preferably constituted by conveying rolls (7), for conveying the preferably strip-like substrate material (9) past the electrodes (24), characterized in that the chambers (4, 5 and 6) of one roughening station (1) do not communicate with one another and in that each chamber (4, 5 and 6) has its own source of electrolyte (14, 15 and 16) and has preferably adjustable heating means (20) and furthermore a current supply means (25 and 26) with individually preset current density and current frequency.
  14. The apparatus as claimed in claim 13, characterized in that the path of the strip-like substrate material (9) through the chambers (4, 5 and 6) is of different length in accordance with the difference in the desired residence time, the middle chamber (5) for the zone II being preferably longer than the first chamber (4) for the zone I and the length of the third chamber (6) for the zone III being at least equal to the length of the first chamber (4) and at the most the length of the second chamber (5), and is preferably in a range between the length of the first chamber and of the second chamber (4 and 5).
  15. The apparatus as claimed in any either of the claims 13 and 14, characterized in that each chamber (4, 5 and 6) is provided with a preferably adjustable frequency amplifier (25) and furthermore current, and respectively, voltage amplifiers (26).
EP90119115A 1989-10-18 1990-10-05 Process and apparatus for the electrochemical graining of a metal surface Expired - Lifetime EP0423555B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3934683A DE3934683A1 (en) 1989-10-18 1989-10-18 METHOD AND DEVICE FOR ELECTROCHEMICALLY Roughening A METAL SURFACE
DE3934683 1989-10-18

Publications (2)

Publication Number Publication Date
EP0423555A1 EP0423555A1 (en) 1991-04-24
EP0423555B1 true EP0423555B1 (en) 1993-09-29

Family

ID=6391673

Family Applications (1)

Application Number Title Priority Date Filing Date
EP90119115A Expired - Lifetime EP0423555B1 (en) 1989-10-18 1990-10-05 Process and apparatus for the electrochemical graining of a metal surface

Country Status (4)

Country Link
US (1) US5041198A (en)
EP (1) EP0423555B1 (en)
JP (1) JPH03134200A (en)
DE (2) DE3934683A1 (en)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5171416A (en) * 1990-10-10 1992-12-15 Space Systems/Loral, Inc. Method for making a battery cell electrode
US5122243A (en) * 1991-07-22 1992-06-16 Eastman Kodak Company Lithographic printing plates comprising an aluminum support grained in a two stage-electrolytic process
US5186795A (en) * 1991-07-22 1993-02-16 Eastman Kodak Company Two-stage process for electrolytic graining of aluminum
WO1993001942A1 (en) * 1991-07-22 1993-02-04 Eastman Kodak Company Two-stage electrolytic graining process, aluminum sheet material produced thereby and lithographic printing plate comprising such aluminum sheet material
DE4129909A1 (en) * 1991-09-09 1993-03-11 Hoechst Ag METHOD FOR Roughening ALUMINUM OR. FROM ALUMINUM ALLOYS AS CARRIER MATERIAL FOR PRINTING PLATES AND A PRINTING PLATE
JP3567402B2 (en) * 1996-06-12 2004-09-22 コニカミノルタホールディングス株式会社 Method for producing lithographic printing plate support, lithographic printing plate support obtained by the method, and photosensitive lithographic printing plate using the support
US20030032879A1 (en) * 1997-07-07 2003-02-13 Steven Quay Microbubble formation using ultrasound
EP1046514B1 (en) * 1999-04-22 2005-07-06 Fuji Photo Film Co., Ltd. Method for producing aluminium support for lithographic printing plate
US20030047464A1 (en) * 2001-07-27 2003-03-13 Applied Materials, Inc. Electrochemically roughened aluminum semiconductor processing apparatus surfaces
JP4038041B2 (en) * 2001-12-05 2008-01-23 富士フイルム株式会社 Electrolytic treatment equipment

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AR204283A1 (en) * 1975-01-21 1975-12-10 Uss Eng & Consult APPARATUS FOR THE ELECTROLYTIC TREATMENT OF METAL STRIPS
US4214961A (en) * 1979-03-01 1980-07-29 Swiss Aluminium Ltd. Method and apparatus for continuous electrochemical treatment of a metal web
JPS57126126A (en) * 1981-01-29 1982-08-05 Yoshiyuki Okamoto Method of etching aluminum foil for electrolytic condenser
US4332651A (en) * 1981-05-20 1982-06-01 Sprague Electric Company AC Etching of aluminum capacitor foil
DE3217552A1 (en) * 1982-05-10 1983-11-10 Hoechst Ag, 6230 Frankfurt METHOD FOR ELECTROCHEMICALLY Roughening ALUMINUM FOR PRINTING PLATE CARRIERS
US4432846A (en) * 1982-12-10 1984-02-21 National Steel Corporation Cleaning and treatment of etched cathode aluminum capacitor foil
US4721552A (en) * 1987-04-27 1988-01-26 Polychrome Corporation Two-step method for electrolytically graining lithographic metal plates

Also Published As

Publication number Publication date
DE59002917D1 (en) 1993-11-04
EP0423555A1 (en) 1991-04-24
DE3934683A1 (en) 1991-04-25
US5041198A (en) 1991-08-20
JPH03134200A (en) 1991-06-07

Similar Documents

Publication Publication Date Title
DE60203047T2 (en) Segmented counterelectrode for an electrolytic treatment system
DE3828291C2 (en) Electrolytic treatment process
WO1998049374A2 (en) Device for electrolytic treatment of printed circuit boards and conductive films
EP0423555B1 (en) Process and apparatus for the electrochemical graining of a metal surface
DE102007026633A1 (en) Apparatus and method for the electrolytic treatment of plate-shaped goods
DE2533319A1 (en) DEVICE FOR THE ELECTROLYTIC TREATMENT OF TAPE MATERIAL OF METAL WITHIN AN ELECTROLYSIS BATH
DE3104699A1 (en) "METHOD AND DEVICE FOR PRODUCING ELECTROLYTICALLY COATED WIRE"
DE4229403C2 (en) Device for electroplating thin plastic films provided with a conductive coating on one or both sides
EP1230441B1 (en) Method and device for the electrolytic treatment of electrically conducting structures which are insulated from each other and positioned on the surface of electrically insulating film materials and use of the method
EP0032530A1 (en) Use of an apparatus for treating a board shaped object by a liquid
DE3135747C2 (en)
DE3108615A1 (en) DEVICE FOR ELECTROLYTICALLY TREATING A METAL STRIP
DE69521754T2 (en) Aluminum support for a planographic printing plate, process for its production and roughening
DE19951324C2 (en) Method and device for the electrolytic treatment of electrically conductive surfaces of pieces of plate and foil material separated from one another and application of the method
DE2619821A1 (en) METHOD AND DEVICE FOR CONTINUOUS ELECTROLYTIC TREATMENT OF A METAL STRIP
AT392090B (en) DEVICE FOR ELECTROPLATING
DE2228424C3 (en) Process for producing a lithographic surface on an aluminum strip by electrolysis
DE2064354C3 (en) Method and device for the continuous pretreatment of a metal foil strip used in particular for the production of lithographic planographic printing plates
DE19633797B4 (en) Device for electroplating electronic circuit boards or the like
EP0728579B1 (en) Doctor blade for intaglio printing machine, method and apparatus for manufacturing same
EP0568728B1 (en) Process and apparatus for electroplating perforated articles
DE69107350T2 (en) Electrolytic treatment apparatus and method for the continuous electrolysis of aluminum products.
EP1033420A1 (en) Process and apparatus for electrochemically graining a support for light-sensitive layers
WO1992011401A1 (en) Arrangement for an installation used for the electrolytic treatment of workpieces
DE3000597C2 (en)

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE ES FR GB IT NL

17P Request for examination filed

Effective date: 19910723

17Q First examination report despatched

Effective date: 19921111

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE ES FR GB IT NL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRE;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.SCRIBED TIME-LIMIT

Effective date: 19930929

Ref country code: FR

Effective date: 19930929

Ref country code: ES

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19930929

Ref country code: GB

Effective date: 19930929

Ref country code: NL

Effective date: 19930929

REF Corresponds to:

Ref document number: 59002917

Country of ref document: DE

Date of ref document: 19931104

EN Fr: translation not filed
NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
GBV Gb: ep patent (uk) treated as always having been void in accordance with gb section 77(7)/1977 [no translation filed]

Effective date: 19930929

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19940701

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed