Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02378350 2002-02-06
COATING DEVICE OF A PRINTING MACHINE
Field of the invention
The invention pertains to a coating device in a printing press according to
the preamble of the main claim.
Background of the invention
A coating device of this class is known from DE 197 57 094 AI. A printing
press described in this document preferably has at least one coating unit.
This
coating unit comprises an impression cylinder, a form cylinder, at least one
applicator roller with an associated adjustable and removable metering system,
e.g., a wiping system, and also a circulation system operated with purrips for
a
coating medium stored in a reservoir. Between the metering system and a feed
pump there is a supply line and a bypass line branches from this bypass line.
The
bypass line is coupled to a suction pump, wherein the bypass line ends in the
reservoir for the coating medium. From this reservoir, the coating medium can
be
fed to the metering system and excess coating medium can be drawn off by
means of a return line with suction pumps into this reservoir. In a
refinement, the
supply line and the return line are coupled to a purification container by
means of
switch valves, so that the lines can be purified before changing the coating
medium. In one configuration, the printing press has two coating units, each
with a
chamber wiping system and an indexed applicator roller, and each with a
metering
roller and an applicator roller (two-roller system).
The disadvantages here are the relatively high cost in terms of device
technology and also the risk that different coating media will intermix within
the
coating device.
Summary of the invention
The basic objective of the invention is to disclose a coating device of the
initially mentioned type, which prevents the stated disadvantages, which has a
simple construction, and which considerably reduces preparation times.
The objective is realized according to the invention by the constitutional
features of the main claim. Refinements follow from the subordinate claims.
The first advantage is based on the fact that the lines in the circulation
system can be essentially disconnected quickly within the coating device and
purified outside of the coating device and [sic].
Likewise, it is advantageous that expensive circulation systems with switch
valves, etc., be eliminated, so that merely a supply line and a return line
with
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CA 02378350 2005-02-17
corresponding pumps can be coupled to the metering system. In this way, the
supply lines and the return lines within the coating device, preferably
including the
metering system, can be completely exchanged. For the pumps, at least the
parts
that are in contact with the coating medium can be exchanged. Furthermore, it
is
advantageous that for the use of various ~~oating media, several corresponding
circulation systems can be used. Here, one circulation system can be used
exclusively for each coating medium. In the preferred configuration, the
circulation
systems (including pumps and, if necessary, the metering system) are marked
for
the corresponding coating medium.
A further advantage is that the circulation systems can have a shorter
length than the initially mentioned state of the art. Thus, a quick-response
metering system can be achieved.
In addition, it is advantageous that the circulation system is easily
accessible and a quick exchange can be. realized both for repair or for line
blockage, e.g., due to foreign particles (dried coating residue) or stoppage
build
up within the circulation system. Such line blockages can occur, e.g., due to
the
heat effects of adjacent systems (e.g., dryers).
Finally, it is an advantage that the circulation system can be adapted to the
processing medium. Thus, e.g., for an aquE:ous dispersion coating, a
transparent
circulation system can be used, and for a UV coating, a light-protected
circulation
system can be used.
In accordance with a first broad aspect of the present invention, there is
provided a coating device in a printing press, formed by an impression
cylinder, a
form cylinder, an applicator roller with an ;associated adjustable and
removable
metering system, wherein the metering systE:m connects to at least one
circulation
system operated with pumps for a fluid medium stored in a reservoir,
characterized in that there is a supply line and a return line that can be
disconnected within the coating device in the circulation system, the pumps
are a
hose pump system, for which the lines can be exchanged in the pump head, and
for the processing of different media in the coating device an individual
supply line
and an individual return line for one medium can be exchanged for that of
another
medium, wherein the medium remaining in the coating unit can be returned to
the
corresponding reservoir before the exchange process.
In accordance with a second broad aspect of the present invention, there is
provided a coating device in a printing press, formed by an impression
cylinder, a
form cylinder, an applicator roller with a corresponding adjustable and
removable
metering system, wherein the metering systE;m connects to at least one
circulation
system operated with pumps for a fluid medium stored in a reservoir,
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characterized in that there is a supply line and a return line that can be
disconnected within the coating device in the circulation system, the pumps
are a
pump cylinder system, for which the cylinder parts contacting the medium can
be
exchanged, and for using different media in the coating device, an individual
supply line, an individual return line, as wE:ll as at least the parts of the
pumps
contacting the medium for can be exchanged for that of another medium, wherein
medium still in the coating unit can be returned into the corresponding
reservoir
before the exchange process.
In accordance with a third broad aspect of the present invention, there is
provided a coating device in a printing press, formed by an impression
cylinder, a
form cylinder, an applicator roller with a corresponding adjustable and
removable
metering system, wherein the metering syst~:m connects to at least one
circulation
system operated with pumps for a fluid medium stored in a reservoir,
characterized in that there is a supply line and a return line that can be
disconnected within the coating device in the circulation system, the pumps
are a
rotary pump system, for which the pump head contacting the medium can be
exchanged, and for using different media in the coating device, an individual
supply line, an individual return line and also at least the parts of the
pumps
contacting the medium can be exchanged for that of another medium, wherein the
medium remaining in the coating unit can be returned to the corresponding
reservoir before the exchange process.
Brief Description of the Drawings
The invention will be described in more detail below with reference to an
embodiment. Shown are:
Figure 1, an offset printing press with two coating devices,
Figure 2, a coating device with a wiping system.
Examples
A sheet-fed rotary printing machine is illustrated in a series production
construction according to Figure 1. Here, se~reral offset printing presses for
multi-
color printing with printing cylinders are arranged in series and are
connected to
each other with transfer cylinders or turn-over systems. The partial view of
such a
printing press shown in Figure 1 is used, among other things, for inline
surface
treatment. Thus, only a final printing press 14 with a plate cylinder 13, a
rubber-
blanket cylinder 12, and a printing cylinder 1 as a sheet-guidance cylinder is
shown. An inking system and, if necessary, ~~ damping system, is associated
with
the plate cylinder 13, which will not be discussed in more detail here.
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A first coating system 15, which is formed by a form cylinder 2, an indexed
applicator roller 3, and also a metering system, particularly a wiping system
4,
e.g., a doctor blade, is arranged after the printing press 14 in the
conveyance
direction 5. Here, the indexed applicator roller 3 and the wiping system 4
form the
metering system and the printing cylinder 1 is associated with the form
cylinder 2.
A dryer device 20, e.g., an infrared dryer, is arranged after the first
coating
system 15, and this dryer device is associated with an adjacent printing
cylinder
1 or an adjacent transfer cylinder 17. A second coating system 16 with the
form
cylinder 2, preferably an indexed applicator roller 3 and the wiping system 4,
follows the drying device 20 in the conveyance direction 5. The printing
cylinders
1 of the printing press 14, the coating systems 15, 16, and also the drying
device
are connected together by means of transfer cylinder 17 for the sheet
transport. An arm 18, which feeds the sheet-like printed material to an output
stack by means of continuous conveyor system 19 in a known way and deposits
15 it there, follows the second coating system 16 in the conveyance direction
5. The
rubber-blanket cylinder 12 in the printing press 14 carries, e.g., a rubber
blanket,
and the form cylinders 2 of the coating systems 15, 16 carry, e.g., a flexible
high-
pressure plate. The sheet-guidance cylinders (printing cylinder 1 and transfer
cylinder 17), the form cylinder 2 with associated applicator roller 3, and the
20 wiping system 4 are supported in side stands 11. The sheet-guidance
cylinders
1, 17 are twice as large as the plate cylinder 13 or form cylinder 2. In the
printing
presses 14 or coating systems 15, 16, a sheet-guidance device 6 arranged
upstream and a sheet-guidance device 7 arranged downstream are each
associated with a printing/coating gap.
The wiping system 4 is preferably a chamber wiper with a wiping sheet
that can be adjusted in the positive and negative directions of rotation of
the
applicator roller 3. The wiping system 4 connects to at least one supply line
21
and at least one return line 22 for the supply of a fluid medium by means of a
sealed circulation system. The preferred fluid medium is a coating, e.g., an
aqueous dispersion coating, a printing ink, e.g., flexo-printing ink, andlor a
cleaning fluid that can be processed in such circulation systems. Thus, the
circulation system is formed from the supply line 21 and also the return line
22
connected to a pump system with pumps 24, 25 for the coating, ink, or cleaning
fluid supply or their return. The return line 22 can be directly connected to
the
wiping system .4 or indirectly to a storage tank that connects to the wiping
system
4. Supply line 21 and return line 22 are not limited to one line. For example,
several supply lines 21 or return lines 22 can be associated with
corresponding
metering systems 3, 4 in a circulation system.
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The circulation system (supply line 21, return line 22) ends in a
corresponding reservoir 8-10. Each reservoir 8-10 stores a fluid medium,
preferably of different types. For example, the reservoir 8 has an aqueous
dispersion coating, the reservoir 9 has a UV coating, and the reservoir 10
stores a
cleaning fluid. The number of reservoirs 8-10 is not limited to the present
example.
The supply lines 21, return lines 22, the metering system, particularly the
wiping
system 4, and also at least the parts of the pumps 24, 25 in contact with each
fluid
medium are arranged so that they can be quickly disconnected within the
coating
device.
For processing different fluid media in the coating device, e.g., for a
change in coating, the entire circulation system (supply line 21, return line
22),
wiping system 4, and at least the parts of the pumps 24, 25 in contact with
the
medium are exchanged.
This means that these elements can be quickly removed from the coating
device 15, 16 and exchanged for another circulation system (supply line 21,
return
line 22), another metering system, preferably wiping system 4, and at least
the
relevant parts of the pumps 24, 25. In this way, supply line 21 and return
line 22
can be connected to the corresponding reservoir 8 or 9 or 10. If there is
still fluid
medium in the coating device 15, 16, this medium can be returned to the
corresponding reservoir 8 or 9 or 10 before the exchange of the previously
mentioned elements.
Preferably, corresponding to the typical number of different fluid media,
also the corresponding number of individual circulation systems 21, 22,
individual
metering systems, e.g., wiping systems 4, as well as at least parts of the
pumps
24, 25, e.g., the feed hose within a hose pump, can also be exchanged. There
are
at least two exchangeable sets of the elements previously mentioned as
examples.
The starter pump 24 and also the return pump 25 are formed preferably as
hose pumps with easily accessible pump heads for changing the feed hose, or
they are completely or partially exchangeable according to the type of pump
24,
25. Thus, for each fluid medium to be processed, there is preferably an
individual
pumping system, so that the intermixing, e.g., of different coatings,
flocculants, or
contaminants within the medium can be prevented and a stable coating quality
guaranteed.
For the conveyance of fluid media, there are different pumps 24, 25. For
example, the following variants can be listed:
- a hose-pump system, for which only the line (hose) in the pump head can
be exchanged,
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- a rotary pump system, for which the pump head in contact with the
corresponding medium can be exchanged,
- an impeller pump system; for which the impeller can be exchanged,
- a pump cylinder system, for which only the cylinder part in contact with
the medium can be exchanged and the control part remains in the coating
device.
The circulation system 21, 22, the metering system, particularly the wiping
system 4, and also the relevant parts of the pumps 24, 25 can be easily
connected or disconnected within the coating device and thus can be exchanged
quickly. Preferably, the pumps 24, 25 are integrated with the machine
protection,
so that for an at least partial exchange, e.g., of the feed hose, just one
opening of
a flap or one seal for easy access to the pumps 24, 25 is required. An
otherwise
typically expensive fixed installation of the circulation system, e.g., to a
side stand
11, is eliminated. By using an arbitrary number of circulation systems 21, 22,
modular expansion of the lines can also be realized. If necessary, the use of
a
cleaning fluid is required only for a general cleaning before the exchange of
the
circulation system 21, 22, the wiping system 4, and also the relevant parts of
the
pumps 24, 25.
The final cleaning itself occurs outside of the coating device, e.g., also
through a circulation cleaning process. Here, e.g., a mobile cleaning unit can
be
used, in which the circulation system 21, 22, as well as, if necessary, at
least parts
of the metering system, e.g., the wiping system 4, and also the relevant parts
of
the pumps 24, 25 can be used and cleaned.
The pumps 24,25 and also the circulation systems 21, 22 can be adapted
to the specific characteristics of the fluid media to be processed.
Furthermore,
circulation systems 21, 22 and pumps 24, 25, as well as metering systems,
e.g.,
the wiping system 4, can be coded, such that the special circulation system
21,
22, the pumps 24, 25, and also the special metering system, e.g., the wiping
system 4 can always be used for the same media for repeated use.
The invention is not limited to the present example. In addition to the
described metering system with indexed applicator roller 3 and wiping system
4,
other metering systems can be used in the coating devices (coating systems 15,
16). The circulation system with supply line 21 and return line 22, as well as
at
least the parts of the pumps 24, 25 (relevant parts) contacting the fluid
medium
can be quickly disconnected within a coating device (15, 16) as already
mentioned. Thus, in one configuration, the metering system is formed by an
applicator roller 3 with an adjacent metering roller (crushing roller system
or two-
roller press). One such metering system is known, a g., from DE 34 27 898 CI.
The applicator roller 3 and metering roller form a common roller gap, and a
supply
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line 21 supplies the fluid medium into this gap from above. There are outlets
with
side wipers at both front sides of the applicator roller 3 and the metering
roller,
preferably with seals, wherein the outlet or side wiper are each connected to
a
return line 22. Alternatively, the return line 22 is connected to a collection
tank for
discharge (by means of at least one outlet) underneath the common roller gap
of
the applicator roller 3 and the metering roller. The outlets, as well as the
feed and
return line 21, 22, can be quickly disconnected within the coating device 15,
16. In
this way, for processing different media in addition to the exchangeable
feedlreturn line 21, 22, there is a corresponding exchangeable outlet (with or
without side wiper), preferably for each medium.
In another configuration, the metering system is formed by an
applicator roller 3 and a scoop roller that travels into a storage container,
wherein, when necessary, other rollers can be inserted, e.g., in series or as
rider rollers. Such a metering system is known, e.g., from DE 41 33 914 AI. A
supply line 21 supplies the fluid medium into this metering system at the
storage container, so that the scoop roller is wetted and the medium can be
supplied to the applicator roller 3. The storage container contacts at least
one
of the return lines 22 that discharges from the storage container. Thus, for
processing various media, in addition to the exchangeable feed/return line 21,
22, there is a corresponding exchangeable storage container, preferably for
each medium. The circulation system 21, 22 of the metering system (chamber
wiping system, two-roller press with common roller gap and supply line 21
supplying from above, scoop-roller press), as well as relevant parts of the
pumps 24, 25 can likewise be cleaned individually or together outside of the
coating device 15, 16.
Likewise, the circulation system 21, 22, the metering system, as well as the
relevant parts of the pumps 24, 25 can be cleaned before an exchange process.
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