[0001] The present invention concerns the field of powder coating, and in particular a powder
coating apparatus able to quickly carry out a color change.
[0002] As known, in a powder coating plant, painting powder is withdrawn from a source and
placed inside a container, where it is sieved and then directed, typically by mixing
it with compressed air, to a dedicated delivering device. This delivering device is
generally shaped as a gun and adapted to spray painting powder against the objects
to be painted. Due to electrostatic effect, the powder adheres to the objects. The
objects are then heated in order to melt the painting powder, which then forms a colored
layer adhering to the object itself.
[0003] The painting powder directed to the gun is of a single color. When different colors
have to be applied on the same object, or when in a plant the object to be colored
is changed, there is the need to change the source of the paint, i.e. to change the
color of the paint, and all the elements that came into contact with the paint of
the previous color have to be cleaned, so as to prevent residues of the previous color
from mixing with the painting powder of the new color, thereby causing obviously unwanted
effects.
[0004] These operations are known in the art as "color change" operations. During these
operations, the plant is not working, i.e. no objects are colored. If the color change
takes too much time, the plant productivity decreases.
[0005] Special care is required for the cleaning operations of the various elements, and
in particular of the container receiving the powder from the source and directing
it, typically after sieving, to the gun. It is therefore known to carry out these
operations manually. Although a certain degree of precision in cleaning operations
is guaranteed, the time required for a color change in such conditions is particularly
high.
[0006] Automated systems for cleaning the container are also known, which, although reducing
the time required for the color change, are not able to achieve completely satisfactory
color-change times.
[0007] US 2009/0232980 discloses a system for coating articles, the system comprising: an applying device
which releases the coating material in powder form; a supplying device which supplies
the coating material to the applying device. The supplying device is configured in
such a way that it is able to transport the pulverulent coating material in a plurality
of powder containers including an abrasion-proof material; at that end of the supplying
device, which faces towards the applying device, an opening device is provided which
is able to open each of the plurality of the powder containers and remove the pulverulent
coating material from within and pass it on to the applying device.
[0008] US 2013/0019970 discloses a powder supply system for supplying powder to a powder spray device comprising
a powder supply hopper, a powder fluidizing device for fluidizing powder positioned
in the powder supply hopper, and a powder pump for conveying powder from the powder
supply hopper to the spray device. The powder supply hopper is pivotally mounted to
a support structure.
[0009] US 2002/0032468 discloses a powder facility used for spray coating and comprising at least one injection
unit, at least two powder stations and at least one cleaning unit which are mutually
displaceable in program-controlled manner in order to alternatively convey powder
from one of the powder receptacles of the powder stations or to clean the powder-flow
itineraries using compressed cleaning air.
[0010] Purpose of this invention is therefore to provide an apparatus and a method for carrying
out a color change in short time.
[0011] The present invention solves this and other purposes by means of an apparatus and
a method according to the independent claims. Preferred aspects are set forth in the
dependent claims.
[0012] According to an aspect of the invention, an apparatus for the powder coating of an
object includes:
- at least a first and a second containers for painting powder;
- means for the movement of the first and second containers between an operative position
and a cleaning position, which are configured so that, when the first container is
in the operative position, the second container is in the cleaning position, and so
that when the first container is in the cleaning position, the second container is
in the operative position;
- means for cleaning a container, which are configured to empty and clean the first
or the second container, when the first or second container is in the cleaning position;
- means for withdrawing painting powder from the first or second container, when the
first or second container is in the operative position, and for feeding it to a device
for delivering painting powder onto an object to be painted;
[0013] The alternate movement of the containers between the two positions allows cleaning
operations to be carried out on a container, while the other container is operated
to feed powder against an object to be painted. Therefore, when carrying out a color
change, it is possible to reverse the positions of the two containers, so that the
previously used container can be cleaned, and the other previously cleaned container
can be used to start the painting operations again. The next time color is changed,
these operations are repeated. Therefore, thanks to this solution, a succession of
color changes can be carried out in shorter time.
[0014] According to an aspect of this invention, the apparatus comprises means to refill
the first or second container, which are preferably configured to refill the first
or second container when the first or second container is in operative position.
[0015] According to an aspect of the present invention, the apparatus comprises at least
two painting powder stocks, and the refilling means are selectively connectable to
the stocks. This further reduces the time required for a color change.
[0016] According to a further aspect, the apparatus comprises movement means to move the
painting powder stocks. In this way, the operations for refilling the containers,
as well as the operations for cleaning them, can be automated and therefore the operations
of a color change can be automated.
[0017] According to a further aspect, at least one of the containers includes:
- a sieving chamber to sieve painting powder to be sieved,
- a collecting chamber for the sieved painting powder,
- at least one sieve arranged next to at least one of the external surfaces of the sieving
chamber, wherein the sieving chamber (12) is arranged at least partially, and preferably
completely, within the collecting chamber, and comprises at least one opening for
the inlet and/or outlet of powder.
[0018] According to a further aspect, the aforementioned sieving chamber has at least one
cavity to allow at least part of the cleaning means to pass through the sieving chamber
into the collecting chamber. In addition, at least one portion of the cleaning means
is configured so as to pass through at least one cavity during the cleaning of the
container.
[0019] An aspect of the present invention further concerns a process for carrying out a
color change by means of an apparatus according to one of the above described aspects,
the process comprising the steps of:
- (a) arranging a first container, comprising painting powder of a first color, in operative
position and a second container in cleaning position by the movement means;
- (b) withdrawing painting powder from the first container by the withdrawing means
and feeding it to a device for delivering painting powder against an object to be
painted;
- (c) emptying the second container, in case the second container contains painting
powder, and inserting, at least partially, the cleaning means into the second container
in order to clean the second container;
- (d) disengaging the withdrawing means from both the first container and the second
container;
- (e) operating the movement means in order to bring the first container to the cleaning
position and the second container to the operative position;
- (f) refilling the second container with painting powder of a second color;
- (g) withdrawing painting powder of the second color from the second container and
feeding it to a device for delivering painting powder;
- (h) emptying the first container, in case the first container contains painting powder,
and inserting, at least partially, the cleaning means into the first container in
order to clean the first container;
wherein:
- at least part of step (c) occurs simultaneously with step (b)
- step (e) may be carried out before, or simultaneously with, or after step (f), preferably
after step (f) so that the second container is refilled when it is in the operative
position;
- at least part of step (h) occurs simultaneously with step (g).
[0020] According to a particular aspect, during step (f) movement means are operated to
move a stock containing painting powder of the second color towards refilling means.
[0021] It should be noted that the operative position of the first container coincides with
the operative position of the second container. Similarly, the cleaning position of
the first container coincides with the cleaning position of the second container.
In other words, the two containers are alternated between the same two positions.
[0022] However, the cleaning positions and/or the operative positions can be different from
each other. In other words, the first container can be cleaned in a position different
from the position where the second container is cleaned, and/or powder can be withdrawn
from the first container at a position different from the position in which powder
can be withdrawn from the second container.
[0023] Hereinafter, referring to the appended figures, exemplary and non-limiting embodiments
of the present invention will be described, wherein:
- figure 1 is a schematic view of a coating apparatus according to a possible embodiment;
- figures 2 - 8 are subsequent views of the color-change steps of an apparatus according
to figure 1, and in which figures 5A and 5B are schematic plan views of the condition
of figure 5;
- figures 9A, 9B are schematic views of a coating apparatus according to a first embodiment
alternative to that of figures 1 - 8;
- figures 10A, 10B are schematic views of a coating apparatus according to a second
embodiment alternative to that of figures 1 - 8;
- figure 11 is a schematic view of a coating apparatus according to a third embodiment
alternative to that of figures 1 - 8;
- figures 12 - 14 are views of a possible container that can be used in a coating apparatus
according to a possible embodiment;
- figure 15 is a view of the container of figures 12 - 14, inside which there are possible
cleaning means that can be used in a coating apparatus according to a possible embodiment;
- figure 16 is a perspective view of the cleaning means of figure 15.
[0024] A powder coating apparatus 1 comprises at least a first container 10 and a second
container 20 for the painting powder.
[0025] The containers 10, 20 can be connected in a known way to paint sources or stocks
2, so as to allow them to be filled with painting powder. As mentioned above, the
containers 10, 20 are adapted to receive painting powder from sources or stocks 2
and to be connected to dedicated means 3 (better described below) for withdrawing
the painting powder and sending it to a device 3c for delivering painting powder on
an object to be painted.
[0026] Various types of containers 10, 20, known in the art, can be used according to the
present invention. Preferably, the containers 10, 20 have the same shape (i.e. they
are substantially identical), and in particular the shape described below. For the
sake of simplicity, an embodiment of the containers, with particular reference to
the first container 10, is now described in detail. However, the following description
applies to the second container 20 too.
[0027] A container 10 for sieving painting powder comprises a sieving chamber 12 and a collecting
chamber 13.
[0028] The container 10 is typically shaped like a bowl, which usually has cylindrical shape.
Generally, the container 10 is open at a base.
[0029] Typically, the collecting chamber 13 is at least partially defined by the side walls
of the container 11. In the embodiment shown, the collecting chamber 13 has a bottom
13a inserted inside the container 10, which defines the lower surface of the collecting
chamber 13, while the side surfaces (or the side surface in this case) of the collecting
chamber are defined, as mentioned, by the side walls (or the side wall in this case)
of the container 10. Preferably the bottom 13a is obtained by means of a porous septum,
which allows the passage of air, but prevents the passage of the powder. An air inlet
13b can be arranged below the bottom of the collecting chamber, so that air passes
through the porous septum in order to fluidize the sieved powder contained inside
the collecting chamber 13.
[0030] However, the possibility of having a collecting chamber 13 entirely contained within
the container 10 is not excluded. As mentioned above, the collecting chamber 13 is
typically open on top, so that the means 3 can withdraw the sieved powder from the
container 10.
[0031] The sieving chamber 12 may have different shapes. The sieving chamber preferably
defines a substantially enclosed room (with the exception of the inlet/outlet or the
inlets/outlets for the painting powder) separated from the collecting chamber 13.
[0032] Typically, the sieving chamber 12 further has at least one external surface 12b,
12c, 12d adapted to define a space or room in which the powder to be sieved can be
inserted and in which impurities or anyway elements that did not pass through the
sieve 14 (better described below) can be retained. As discussed above, this space
or room defined by the sieving chamber 12 is preferably substantially closed (with
the exception of the inlet/outlet means of the painting powder), i.e. separated from
the room defined by the collecting chamber, so as to prevent the powder to be sieved
and contained in the sieving chamber 12 from entering the collecting chamber 13 without
passing through the sieve 14.
[0033] In this regard, a less preferable solution is possible in which the sieving chamber
is partially open, provided that contact between the powder to be sieved and the powder
already sieved can be prevented. For example, the shape of the sieving chamber 12
may be similar to that of the collecting chamber, i.e. cylindrical with the upper
base open.
[0034] The sieving chamber preferably has at least one base surface 12b, 12c and at least
one side surface 12d. In the embodiment shown, in particular, the sieving chamber
12 has cylindrical shape, whereby it is provided with two base surfaces 12b, 12c and
one side surface 2d.
[0035] The sieving chamber 12 is further provided with at least one sieve 14 placed next
to at least part of an external surface 12b, 12c, 12d.
[0036] Preferably, the sieve 14 is arranged on at least 50%, more preferably at least 75%,
of the external surfaces of the sieving chamber. Preferably, the sieve 14 should cover
a percentage as large as possible of the external surfaces of the sieving chamber
2. In the embodiment shown, according to a preferred solution, the sieve 14 covers
substantially entirely the external surfaces (or the external surface) 2b, 2c, 2d.
In particular, it should be noted that the sieve 14 is explicitly shown only in figure
13, and only on half the sieving chamber 12, in order to allow the other half of the
chamber itself to be more simply shown. However it is understood that, in the embodiment
shown, the sieve 14 is substantially arranged outside the whole sieving chamber 12.
[0037] Preferably, the sieving chamber is formed by a frame 12f on which the sieve 14 is
mounted; therefore at least part of the external surfaces 12b, 12c, 12d can consist
exclusively of the sieve 14.
[0038] The sieve 14 typically comprises a wire mesh whose "aperture", i.e. an average distance
between successive mesh wires, is preferably less than or equal to 400 microns.
[0039] The sieve is typically constrained to the sieving chamber by an anti-vibration support.
[0040] The sieving chamber 12 has at least one opening 12a to allow powder inlet/outlet.
In particular, in the embodiment shown, the sieving chamber has an opening 12a which,
in normal conditions of use, is used to allow the inlet of powder to be sieved into
the chamber. During the cleaning operations of the container, on the other hand, the
opening 12a is used to suction the residues held inside the sieving chamber 12 at
the end of the sieving operations (e.g. too large powder particles, impurities, etc.).
[0041] However, different openings can be used, for example openings exclusively dedicated
to the inlet of powder, and openings exclusively dedicated to outlet of powder and/or
impurities.
[0042] According to a particular aspect, the sieving chamber 12 has one or more cavities
11 (two cavities 11 in the particular embodiment shown) to allow cleaning means 4
(better described below) to pass in the container 10, and in particular in the collecting
chamber 13.
[0043] The sieving chamber 12 is at least partially, and preferably entirely, arranged inside
the collecting chamber 13. Therefore, preferably the sieving chamber 12 is inside
the collecting chamber 13 and separate therefrom. As mentioned above, the sieving
chamber 12 and the collecting chamber preferably have similar shape. Therefore, according
to an aspect the side surface 12d (or the side surfaces in case of polyhedral shape)
of the sieving chamber 12 faces the side (inner) surface of the collecting chamber
13.
[0044] In this way, the container remains compact, and the powder sieved by the sieve 14
can be more easily retained inside the collecting chamber 13.
[0045] The container 10 typically has a support 15 on which the sieving chamber 12 is mounted.
The support 15 may have different shapes adapted to bear the collecting chamber 12.
In the shown embodiment the support 15 has truncated-cylinder shape. Screws 16, or
similar threaded elements, can be used to constrain the sieving chamber 12 to the
respective support 15.
[0046] According to a possible embodiment, as shown in the figures, the container 10 has
means 17 to vibrate the sieving chamber 12, or at least the sieve 14. These means
17 may be general means known in the art and suitable for this purpose.
[0047] In particular, in the embodiment shown, there are vibrating elements 17a, 17b. These
vibrating elements 17a, 17b are preferably arranged in combination with anti-vibration
supports 17c, which allow the vibration to be transferred to the sieve 14, thus dampening
the vibration transmitted to the container 10. Different number, arrangement and types
of vibrating elements can be used with respect to what has been shown (for example
a single vibrating element placed in direct or indirect communication with the sieve
14).
[0048] Referring to the figures, the element 17a is an ultrasound vibrating element, whereas
the element 17b is a pneumatic vibrating element. An air inlet 18 is preferably placed
on the container 10 in order to supply air to the pneumatic vibrating element 17b
for the optimal operation thereof.
[0049] As specified above, although the solution described above is preferred for the containers
10, 20, there is the possibility of using different types of containers that are able
to receive (and preferably sieve) the painting powder from a stock 2, and to deliver
it to the withdrawing means 3 that withdraw the paint itself.
[0050] The apparatus 1 is further provided with means 5 to move the containers 10, 20 between
an operative position P1 and a cleaning position P2. Various movement means 5 to move
the containers 10, 20 can be used. Typically, the containers 10, 20 are placed on
a movable support 5a, which is moved by a motor M (schematically shown only in figure
1). The movable support 5a can be for example a rotating platform (as shown for example
in the embodiment of figures 1 - 8), or an element movable along a path (as shown
for example in the embodiments of figures 9A - 11).
[0051] In general, the movement means 5 allow the containers 10, 20 to be moved so that,
when the first container 10 is in the operative position P1, the second container
is in the cleaning position P2, and so that when the first container 10 is in the
cleaning position P2, the second container is in the operative position P1.
[0052] The "operative position P1" is the position in which the container 10, 20 can be
used to withdraw painting powder therefrom and send it to a dedicated delivering device
3c to allow the painting of an object 100.
[0053] The "cleaning position P2" is the position in which cleaning operations can be carried
out on the container 10, 20.
[0054] Preferably, as shown in figures 1 - 8, there is a single operative position P1 and
a single cleaning position P2. In other words, the two containers 10, 20 are preferably
alternated between the two positions P1, P2. A single operative position P1 is then
configured so as to allow painting powder to be alternately withdrawn from the first
container 10 and the second container 20. Similarly, a single cleaning position P2
can be configured so as to alternately clean the first container 10 and the second
container 20.
[0055] In this embodiment the same cleaning means 4 are alternately inserted into the first
container 10 and the second container 20. Similarly, the same withdrawing means 3
are alternately inserted into the first container 10 and the second container 20.
[0056] In possible variations, the operative position P1' of the first container 10 differs
from the operative position P1" of the second container and/or the cleaning position
P2' of the first container 10 differs from the cleaning position P2" of the second
container 20. In this case, different cleaning means 4 and/or different withdrawing
means 3 must be provided. This increases the costs of the apparatus 1 but also saves
further time in color change operations, as better discussed below.
[0057] Possible embodiments according to this configuration are schematically shown in figures
9A - 11.
[0058] In figures 9A, 9B, the containers 10, 20 share the same operative position P1, i.e.
they are alternately arranged in the same operative position, while the cleaning positions
P2', P2" are different from each other, i.e. the cleaning position P2' of the first
container is different from the cleaning position P2" of the second container 20.
In this embodiment, the same withdrawing means 3 are alternately coupled to the first
container 10 and the second container 20. First cleaning means 4' can be coupled only
to the first container 10, whereas second cleaning means 4" can be coupled only to
the second container.
[0059] In the alternative solution of figures 10A, 10B, both operative positions P1 and
cleaning positions P2 are different for the two containers 10, 20. In this embodiment,
first cleaning means 4' can be coupled only to the first container 10, whereas second
cleaning means 4" can be coupled only to the second container. Similarly, first withdrawing
means 3' can be coupled only to the first container 10, whereas second withdrawing
means 3" can be coupled only to the second container. In other words, the operative
position P1' of the first container differs from the operative position P1" of the
second container 20, and the cleaning position P2' of the second container differs
from the cleaning position P2" of the second container 20.
[0060] By properly arranging the various elements of the apparatus 1, first withdrawing
means 3' couplable only to the first container 10, and second withdrawing means 3"
couplable only to the second container can be provided, but single cleaning means
4 are (alternately) couplable to either the first container 10 and the second container
20. In other words, the operative position P1' of the first container differs from
the operative position P1" of the second container, whereas the cleaning position
P2 of the first container 10 coincides with the cleaning position P2 of the second
container 20. A possible embodiment providing this solution is schematically shown
in figure 11.
[0061] In general, according to the present invention, when the first container 10 is in
the operative position P1, P1', the second container is in the cleaning position P2,
P2", and vice versa, so that while a container is used to paint an object 100, the
other container is cleaned.
[0062] The withdrawing means 3 can be of various types known in the art. Typically, the
withdrawing means comprise a suctioning element 3a that can be inserted into the container
10, 20. A hose 3b, or similar element, is connected to a delivering device 3c (typically
in the form of a user-operated gun) to deliver painting powder on an object to be
painted 100. Proper devices known in the art and not shown in detail (typically comprising
an air compressor) are used to allow the suction of the painting powder through the
withdrawing means 3.
[0063] Various types of cleaning means 4, known in the art, can be used with the present
invention. Typically, these cleaning means comprise both suctioning elements, to allow
the suction of the painting powder that may remain in the container 10, 20, and elements
adapted to deliver a cleaning fluid at least against the walls of the container 10,
20 (and preferably also of the sieve 14 that may be held in the container 10, 20).
According to a possible aspect the cleaning fluid is air, so the same device can be
used alternatively either to suction the residual powder and to feed air to the container
10, 20 in order to clean it.
[0064] According to a possible embodiment the cleaning means 4 preferably comprise at least
one movable arm 4a. According to a possible embodiment, the movable arm 4a comprises
a typically elongated body 41a and a head 42a laterally protruding with respect to
the body 41a. Furthermore, the movable arm has a plurality of nozzles 4b adapted to
eject a fluid to clean the container. Typically such fluid is air. In this case, the
cleaning device 4 comprises or is connectable to an air source (known in the art and
not shown in the figures), e.g. a compressor.
[0065] Preferably, the nozzles 4b are arranged so that the fluid is ejected in several directions.
More specifically, each nozzle typically has a main direction of fluid ejection. This
direction may be different for different nozzles. In this way, for example, different
elements of the container or even different surfaces of the same container can be
effectively cleaned.
[0066] Generally, the movable arm 4a is hollow inside in order to facilitate the passage
of the air or fluid used for cleaning the container 10.
[0067] The arm 4a can be moved in various directions according to the needs. In an embodiment
shown in the figures, the movable arm 4a is rotatable. In particular, the cleaning
means 4 have a longitudinal A axis typically coinciding, in use, with the longitudinal
axis of the container 10, and the movable arm 4a can be rotated around this axis A.
According to a possible solution, the movable arm 4a has a L-shaped body 41a having
a first portion substantially orthogonal to the axis A and a second portion substantially
parallel to the axis A.
[0068] Appropriate motorized means can be provided to move the movable arm 4a. Preferably,
however, as in the embodiment shown, the arrangement of the nozzles 4b is such that,
when the cleaning fluid is ejected therefrom, the movable arm is naturally rotated.
[0069] In other words, due to fluid ejection from the nozzles 4b, a torque is applied on
the movable arm 4a, which is then rotated.
[0070] An actuator 43, e.g. an electric or pneumatic one, may also be provided in order
to arrange the arm 4a (or arms 4a) in a position such as to allow the device 4 to
be removed from the container 10, e.g. a position in which the arm 4a is placed at
the cavities 2e.
[0071] More than one movable arm 4a can be provided on the cleaning means 4. In the shown
embodiment there are two moving arms 4a that are both rotatable, preferably in synchronous
way.
[0072] The cleaning means 4 preferably also have a suctioning element 4c that can be inserted
into the sieving chamber 12, typically through the opening 2a. Generally, as in the
embodiment shown, this suctioning element 4c is in the form of a tubing connected
in a known way to a suctioning element known in the art, which can alternatively be
part of the means 4, or an external element specifically connected thereto.
[0073] The configuration of the cleaning device 4 and container 10 preferably allows the
former to be inserted into the latter. As already mentioned, for example, the sieving
chamber 12 preferably has cavities 11 to allow the cleaning device 4 to be inserted
into the container 10. Referring to the embodiment shown, the cavities 11 are complementarily
shaped with respect to the heads 42a of the movable arms 4a, so as to allow the heads
to pass through the sieving chamber 12, i.e. to go past the sieving chamber when the
cleaning device 4 is moved to be inserted into the container 10.
[0074] Additional devices, not shown in detail, can be used to suction the contents of the
collecting chamber 12 or, before ejecting a cleaning fluid, air can be suctioned by
the nozzles 4b, so as to remove the painting powder left in the container 10, 20.
[0075] Preferably, the apparatus 1 comprises at least two stocks 2a, 2b that can be used
to refill the containers 10, 20 after they have been cleaned. Appropriate refilling
means are provided in the apparatus 1 for this purpose. These means, known in the
art, are adapted to transfer painting powder from a stock to a container 10, 20. Typically,
these withdrawing means 3 comprise a source of compressed air (not shown in detail)
adapted to allow the powder to be suctioned from the stock 2a, 2b and delivered to
the container 10, 20.
[0076] According to a possible aspect, the stock 2a, 2b with the appropriate color, i.e.
the painting powder with the color chosen for filling the container 10, 20, can be
manually arranged in the apparatus 1 at the withdrawing means 3, so as to allow them
to transfer the powder from the stock 2a, 2b to the container 10, 20. According to
a preferred embodiment, the apparatus 1 is provided with movement means 7 adapted
to automatically arrange the stock 2a, 2b containing the powder of the desired color
near the withdrawing means 3. These additional movement means 7 are also known in
the art and may include, for example, a rotating and/or translating platform.
[0077] The apparatus 1 is further provided with a control unit known in the art and not
shown in detail, the latter being adapted to control the operations at least of the
cleaning means 4, the withdrawing means 3 and the movement means 5. The coupling between
the containers 10, 20 and the various devices of the apparatus (cleaning means 4,
withdrawing means 3, etc.) typically occurs by relative movement between the two elements.
This movement can be provided by the movement means 5 (typically by means of a vertical
movement thereof) and/or by means of a movement of the devices themselves, i.e. the
cleaning means and/or the withdrawing means 3, etc. In this case, one or more motors
(not shown in the figures) to move the cleaning means 4 and/or the withdrawing means
3 and/or the refilling means 6, etc., are provided. These motors are in turn connected
to the control unit, so that the latter can control their activation.
[0078] The steps of a color change are now discussed in detail, with particular reference
to figures 1 - 8. As evident to the field technician, the following description also
applies to the embodiments of figures 9A - 11.
[0079] Initially, the movement means 5 are operated so that the first container 10 comprising
painting powder of a first color is arranged in the operative position P1 and the
second container 20 is arranged in the cleaning position P2. This condition is depicted,
in particular, in Figure 1.
[0080] Then, the cleaning means 4 are coupled to the second container 20 and the withdrawing
means 3 are coupled to the first container 10. The second container 20 is cleaned
by the means 4, which direct a fluid, typically compressed air, against the walls
of the container itself. At the same time, painting powder is withdrawn from the first
container by the withdrawing means 3 and fed through the gun or similar device against
object 100 to be painted. This condition is depicted in figures 2 and 3. In particular,
figure 2 shows the step of emptying the second container 20, while figure 3 shows
the step of directing a cleaning fluid against the walls of the second container 20.
[0081] At the end of the cleaning and painting operations, the withdrawing means 3 are disengaged
from the first container 10 and the cleaning means are disengaged from the second
container 20. This condition is depicted in figure 4.
[0082] The movement means 5 are then operated in order to bring the first container to the
cleaning position P2 and the second container 20 to the operative position P1. Figure
5 shows the movement of the two containers 10, 20 by the means 5. In figures 5A and
5B, the movement is further schematically shown in plan view. The arrangement of figure
6 is obtained at the end of the movement.
[0083] As shown in Figure 7, the refilling means 6 are preferably operated so that the second
container 20 is refilled with the painting powder of a second color. This operation
can be carried out when the second container is in the cleaning position (typically
after the cleaning operations) or when the container is in the operative position,
typically before coupling the withdrawing means to the second container 20. In addition,
movable refilling means 6 may be further provided, i.e. able to follow the second
container during its movement between the cleaning position 3 and the operative position,
so as to at least partially refill the second container 20 during this movement.
[0084] As mentioned above, the apparatus may also have additional movement means 7 adapted
to bring the proper stock 2a, 2b (i.e. the one containing the painting powder of the
desired color, i.e. in this case the second color) at the refilling means 6.
[0085] Typically, during these last two steps, cleaning operations also carried out also
on the withdrawing means 3 and/or cleaning means 4, and in general on the various
elements that came into contact with the painting powder of the first color. These
steps are carried out by devices and methods known in the art and are not describe
in detail herein. In order to minimize such cleaning times, different cleaning means
4 and/or withdrawing means 3 may be provided, so that non-operative means can be cleaned
while coupling the other ones to the containers 10, 20. Similar embodiments are briefly
depicted in figures 9A - 11.
[0086] Once the second container 20, refilled with the painting powder of the second color,
is in operative position P1 and the first container 10 is in the cleaning position
P2, the painting operations of an object 100 may be resumed, while the first container
10 is cleaned, as shown in figure 8.
[0087] Thanks to the present apparatus and method, color changes can be sequentially operated,
with substantially identical and reduced waiting time for each color change.
1. An apparatus (1) for the powder coating of an object (100), wherein said apparatus
(1) comprises:
- at least a first and a second container (10, 20) for painting powder;
- means (5) for the movement of said first and second container (10, 20) between an
operative position (P1, P1', P1") and a cleaning position (P2, P2', P2"),
- means (4, 4', 4") for cleaning a container (10, 20), configured to empty and clean
said first or said second container (10, 20), when said first or second container
(10, 20) is in the cleaning position (P2, P2', P2");
- means (3, 3', 3") for withdrawing painting powder from said first or second container
(10, 20), when said first or second container (10, 20) is in the operative position
(P1, P1', P1"), and for feeding it to a device (3c) for delivering painting powder
onto an object (100) to be painted;
characterized in that said means (5) for the movement of said first and second container (10, 20) are configured
so that, when said first container (10) is in the operative position (P1, P1'), said
second container (20) is in said cleaning position (P2, P2"), and so that when said
first container (10) is in the cleaning position (P2, P2'), said second container
(20) is in the operative position (P1, P1").
2. The apparatus (1) according to claim 1, comprising means (6) to refill said first
or second container (10, 20), preferably configured to refill said first or second
container (10, 20) when said first or second container (10, 20) is in the operative
position (P1, P1', P1").
3. The apparatus (1) according to claim 2, comprising at least two painting powder stocks
(2a, 2b), said refilling means (6) being selectively connectable to said painting
powder stocks (2a, 2b).
4. The apparatus (1) according to claim 3, comprising means (7) for the movement of said
painting powder stocks (2a, 2b).
5. The apparatus (1) according to one of the preceding claims, wherein at least one of
said first and second containers (10, 20) comprises:
- a sieving chamber (12) to sieve painting powder to be sieved,
- a collecting chamber (13) for the sieved painting powder,
- at least one sieve (14) arranged at least one of the external surfaces (12b, 12c,
12d) of said sieving chamber (12), wherein said sieving chamber (12) is arranged at
least partially, preferably completely, within said collecting chamber (13), and comprises
at least one opening (12a) for the inlet and/or outlet of powder.
6. The apparatus (1) according to claim 5, wherein said sieving chamber (12) is provided
with at least one cavity (11) allowing at least a portion of said cleaning means (4,
4', 4") to pass through said sieving chamber (12), into said collecting chamber (13),
and wherein at least a portion of said cleaning means (4, 4', 4") is configured to
pass through said at least one cavity (11) during the cleaning of said container (10).
7. A process for a color change by means of an apparatus according to any one of the
preceding claims, comprising the steps of:
(a) arranging a first container (10), comprising painting powder of a first color,
in said operative position (P1, P1') and a second container (20) in said cleaning
position (P2, P2") by means of said movement means;
(b) withdrawing painting powder from said first container (10) by means of said withdrawing
means (3) and feeding it to a device (3c) for delivering painting powder;
(c) emptying said second container (20), in case said second container (20) contains
painting powder, and inserting, at least partially, said cleaning means (4) into said
second container (20) in order to clean said second container (20);
(d) disengaging said withdrawing means (3, 3', 3") from said first container (10)
and disengaging said cleaning means (4, 4', 4") from said second container (20);
(e) operating said movement means (5) in order to bring said first container (10)
to said cleaning position (P2, P2') and said second container (20) to said operative
position (P1, P1");
(f) refilling said second container (20) with painting powder of a second color;
(g) withdrawing painting powder of said second color from said second container (20)
and feeding it to a device (3c) for delivering painting powder;
(h) emptying said first container, in case said first container contains painting
powder, and inserting, at least partially, said cleaning means (4) into said first
container (10) in order to clean said first container (10);
wherein:
- at least part of said step (c) occurs simultaneously with said step (b);
- said step (e) may be carried out before, or simultaneously with, or after said step
(f), preferably after said step (f) so that said second container (20) is refilled
when it is in said operative position;
- at least part of said step (h) occurs simultaneously with said step (g).
8. The process according to claim 7, wherein during said step (f), movement means (7)
are operated to move a stock (2a, 2b), containing said painting powder of said second
color, towards refilling means (6).
1. Vorrichtung (1) zum Pulverbeschichten eines Gegenstandes (100), wobei die Vorrichtung
(1) umfasst:
- mindestens einen ersten und einen zweiten Behälter (10, 20) für Farbpulver;
- Mittel (5) zum Bewegen des ersten und zweiten Behälters (10, 20) zwischen einer
Betriebsposition (P1, P1', P1") und einer Reinigungsposition (P2, P2', P2");
- Mittel (4, 4', 4") zum Reinigen eines Behälters (10, 20), die konfiguriert sind,
um den ersten oder den zweiten Behälter (10, 20) zu leeren und zu reinigen, wenn sich
der erste oder der zweite Behälter (10, 20) in der Reinigungsposition (P2, P2', P2")
befindet;
- Mittel (3, 3', 3") zum Abziehen von Farbpulver aus dem ersten oder zweiten Behälter
(10, 20), wenn sich der erste oder zweite Behälter (10, 20) in der Betriebsposition
(P1, P1', P1") befindet und zu dessen Zuführen zu einer Vorrichtung (3c) zum Zuführen
von Farbpulver auf einen anzustreichenden Gegenstand (100);
dadurch gekennzeichnet, dass die Mittel (5) zum Bewegen des ersten und zweiten Behälters (10, 20) so konfiguriert
sind, dass, wenn sich der erste Behälter (10) in der Betriebsposition(P1, P1') befindet,
sich der zweite Behälter (20) in der Reinigungsposition (P2, P2") befindet und, wenn
sich der erste Behälter (10) in der Reinigungsposition (P2, P2') befindet, sich der
zweite Behälter (20) in der Betriebsposition (P1, P1") befindet.
2. Vorrichtung (1) nach Anspruch 1, umfassend Mittel (6) zum Nachfüllen des ersten oder
zweiten Behälters (10, 20), die vorzugsweise zum Nachfüllen des ersten oder zweiten
Behälters (10, 20) konfiguriert sind, wenn der erste oder zweite Behälter (10, 20)
sich in der Betriebsstellung (P1, P1', P1") befindet.
3. Vorrichtung (1) nach Anspruch 2, umfassend mindestens zwei Farbpulver-Vorräte (2a,
2b), wobei die Nachfüllmittel (6) selektiv mit den Farbpulver-Vorräten (2a, 2b) verbindbar
ist.
4. Vorrichtung (1) nach Anspruch 3, umfassend Mitteln (7) zum Bewegen der Farbpulver-Vorräte
(2a, 2b).
5. Vorrichtung (1) nach einem der vorhergehenden Ansprüche, wobei mindestens einer der
ersten und zweiten Behälter (10, 20) umfasst:
- eine Siebkammer (12) zum Sieben von zu siebendem Pulver,
- eine Sammelkammer (13) für das gesiebte Farbpulver,
- mindestens ein Sieb (14), das an mindestens einer der Außenflächen (12b, 12c, 12d)
der Siebkammer (12) angeordnet ist, wobei die Siebkammer (12) mindestens teilweise,
vorzugsweise vollständig, innerhalb der Sammelkammer (13) angeordnet ist und mindestens
eine Öffnung (12a) für den Einlass und/oder den Auslass von Pulver aufweist.
6. Vorrichtung (1) nach Anspruch 5, wobei die Siebkammer (12) mit mindestens einem Hohlraum
(11) versehen ist, der es mindestens einem Teil der Reinigungsmittel (4, 4', 4") ermöglicht,
durch die Siebkammer (12) in die Sammelkammer (13) zu passieren, und wobei mindestens
ein Teil der Reinigungsmittel (4, 4', 4") derart konfiguriert ist, dass er während
der Reinigung des Behälters (10) durch den mindestens einen Hohlraum (11) zu passieren.
7. Verfahren für einen Farbwechsel mittels einer Vorrichtung nach einem der vorhergehenden
Ansprüche, umfassend die Schritte:
(a) Anordnen eines ersten Behälters (10), der Farbpulver einer ersten Farbe umfasst,
in der Betriebsposition (P1, P1') und eines zweiten Behälters (20) in der Reinigungsposition
(P2, P2 ") mittels der Bewegungseinrichtung;
(b) Abziehen von Farbpulver aus dem ersten Behälter (10) mittels der Abziehmittel
(3) und Zuführen zu einer Vorrichtung (3c) zum Abgeben von Farbpulver;
(c) Entleeren des zweiten Behälters (20), falls der zweite Behälter (20) Farbpulver
enthält, und mindestens teilweises Einführen der Reinigungsmittel (4) in den zweiten
Behälter (20), um den zweiten Behälter (20) zu reinigen;
(d) Lösen der Abziehmittel (3, 3', 3") von dem ersten Behälter (10) und Lösen der
Reinigungsmittel (4, 4', 4") von dem zweiten Behälter (20);
(e) Betätigen der Bewegungsmittel (5), um den ersten Behälter (10) zu der Reinigungsposition
(P2, P2') zu bringen und den zweite Behälter (20) in die Betriebsposition (P1, P1")
zu bringen;
(f) Wiederbefüllen des zweiten Behälters (20) mit Farbpulver einer zweiten Farbe;
(g) Abziehen von Farbpulver der zweiten Farbe aus dem zweiten Behälter (20) und Zuführen
desselben zu einer Vorrichtung (3c) zum Abgeben von Farbpulver;
(h) Entleeren des ersten Behälters, falls der erste Behälter Farbpulver enthält, und
zumindest teilweises Einführen des Reinigungsmittels (4) in den ersten Behälter (10),
um den ersten Behälter (10) zu reinigen;
wobei:
- mindestens ein Teil des Schritts (c) gleichzeitig mit dem Schritt (b) stattfindet;
- der Schritt (e) kann vor oder gleichzeitig mit oder nach dem Schritt (f), vorzugsweise
nach dem Schritt (f), ausgeführt werden, so dass der zweite Behälter (20) nachgefüllt
wird, wenn er sich in der Betriebsposition befindet;
- mindestens ein Teil des Schritts (h) findet gleichzeitig mit dem Schritt (g) statt.
8. Verfahren nach Anspruch 7, wobei während des Schritts (f) Bewegungsmittel (7) betätigt
werden, um einen Vorrat (2a, 2b), der das Farbpulver der zweiten Farbe enthält, in
Richtung der Nachfüllmittel (6) zu bewegen.
1. Appareil (1) pour le revêtement de poudre d'un objet (100), dans lequel ledit appareil
(1) comprend :
- au moins des premier et second récipients (10, 20) pour de la poudre de peinture
;
- des moyens (5) pour le déplacement desdits premier et second récipients (10, 20)
entre une position opérationnelle (P1, P1', P1") et une position de nettoyage (P2,
P2', P2"),
- des moyens (4, 4', 4") pour nettoyer un récipient (10, 20), configurés pour vider
et nettoyer ledit premier ou ledit second récipient (10, 20) lorsque ledit premier
ou second récipient (10, 20) est dans la position de nettoyage (P2, P2', P2").
- des moyens (3, 3', 3") pour retirer de la poudre de peinture dudit premier ou second
récipient (10, 20) lorsque ledit premier ou second récipient (10, 20) est dans la
position opérationnelle (P1, P1', P1") et pour la fournir à un dispositif (3c) pour
délivrer de la poudre de peinture sur un objet (100) à peindre ;
caractérisé en ce que lesdits moyens (5) pour le déplacement desdits premier et second récipients (10,
20) sont configurés de sorte que, lorsque ledit premier récipient (10) est dans la
position opérationnelle (P1, P1'), ledit second récipient (20) soit dans ladite position
de nettoyage (P2, P2") et de sorte que lorsque ledit premier récipient (10) est dans
la position de nettoyage (P2, P2'), ledit second récipient (20) soit dans la position
opérationnelle (P1, P1").
2. Appareil (1) selon la revendication 1, comprenant des moyens (6) pour recharger ledit
premier ou second récipient (10, 20), de préférence configurés pour recharger ledit
premier ou second récipient (10, 20) lorsque ledit premier ou second récipient (10,
20) est dans la position opérationnelle (P1, P1', P1").
3. Appareil (1) selon la revendication 2, comprenant au moins deux stocks de poudre de
peinture (2a, 2b), lesdits moyens de recharge (6) pouvant être raccordés sélectivement
auxdits stocks de poudre de peinture (2a, 2b).
4. Appareil (1) selon la revendication 3, comprenant des moyens (7) pour le déplacement
desdits stocks de poudre de peinture (2a, 2b).
5. Appareil (1) selon l'une quelconque des revendications précédentes, dans lequel au
moins l'un desdits premier et second récipients (10, 20) comprend :
- une chambre de tamisage (12) pour tamiser de la poudre de peinture à tamiser,
- une chambre collectrice (13) pour la poudre de peinture tamisée,
- au moins un tamis (14) agencé au moins sur l'une des surfaces externes (12b, 12c,
12d) de ladite chambre de tamisage (12), dans lequel ladite chambre de tamisage (12)
est agencée au moins en partie, de préférence complètement, dans ladite chambre collectrice
(13) et comprend au moins une ouverture (12a) pour l'entrée et/ou la sortie de poudre.
6. Appareil (1) selon la revendication 5, dans lequel ladite chambre de tamisage (12)
est pourvue d'au moins une cavité (11) permettant au moins à une partie desdits moyens
de nettoyage (4, 4', 4") de passer à travers ladite chambre de tamisage (12) jusque
dans ladite chambre collectrice (13), et dans lequel au moins une partie desdits moyens
de nettoyage (4, 4', 4") est configurée pour passer à travers ladite au moins une
cavité (11) au cours du nettoyage dudit récipient (10).
7. Procédé de changement de couleur au moyen d'un appareil selon l'une quelconque des
revendications précédentes, comprenant les étapes consistant à :
(a) agencer un premier récipient (10) comprenant de la poudre de peinture d'une première
couleur dans ladite position opérationnelle (P1, P1') et un second récipient (20)
dans ladite position de nettoyage (P2, P2") au moyen desdits moyens de déplacement
;
(b) retirer de la poudre de peinture dudit premier récipient (10) au moyen desdits
moyens de retrait (3) et la fournir à un dispositif (3c) pour délivrer de la poudre
de peinture ;
(c) vider ledit second récipient (20), dans un cas où ledit second récipient (20)
contient de la poudre de peinture, et insérer, au moins en partie, lesdits moyens
de nettoyage (4) dans ledit second récipient (20) afin de nettoyer ledit second récipient
(20) ;
(d) dégager lesdits moyens de retrait (3, 3', 3") dudit premier récipient (10) et
dégager lesdits moyens de nettoyage (4, 4', 4") dudit second récipient (20) ;
(e) actionner lesdits moyens de déplacement (5) pour amener ledit premier récipient
(10) dans ladite position de nettoyage (P2, P2') et ledit second récipient (20) dans
ladite position opérationnelle (P1, P1") ;
(f) recharger ledit second récipient (20) en poudre de peinture d'une seconde couleur
;
(g) retirer de la poudre de peinture de ladite seconde couleur dudit second récipient
(20) et la fournir à un dispositif (3c) pour délivrer de la poudre de peinture ;
(h) vider ledit premier récipient, dans un cas où ledit premier récipient contient
de la poudre de peinture, et insérer, au moins en partie, lesdits moyens de nettoyage
(4) dans ledit premier récipient (10) afin de nettoyer ledit premier récipient (10)
;
dans lequel :
- au moins une partie de ladite étape (c) survient simultanément avec ladite étape
(b) ;
- ladite étape (e) peut être réalisée avant, simultanément ou après ladite étape (f),
de préférence après ladite étape (f) de sorte que ledit second récipient (20) soit
rechargé lorsqu'il se trouve dans ladite position opérationnelle ;
- au moins une partie de ladite étape (h) survient simultanément avec ladite étape
(g).
8. Procédé selon la revendication 7, dans lequel, au cours de ladite étape (f), les moyens
de déplacement (7) sont actionnés pour déplacer un stock (2a, 2b) contenant ladite
poudre de peinture de ladite seconde couleur vers les moyens de recharge (6).