Tinting machine

Abstract

Tinting machine and method of operating a tinting machine (1). The tinting machine comprises a plurality of dispensers (3) mounted on a support, e.g. turntable, each dispenser comprising a nozzle (12, 13). The tinting machine further comprises a cleaning tool (15) for cleaning the nozzles, and a replaceable or disposable cleaning liquid reservoir (16) holding a cleaning liquid and recollecting spent cleaning liquid. Recycling of the cleaning liquid (17) can be maintained after saturation of the cleaning liquid.

Description

[0001] TINTING MACHINE

[0002] The invention relates to a tinting machine for selectively dispensing a plurality of colorants or pigment pastes, e . g. , for paints, comprising a support, such as a turntable or a linear table, a plurality of dispensers mounted on the support, each dispenser being provided with a container, a pump and a valve for dispensing the liquid from the container via a nozzle in the valve, a cleaning tool for cleaning the nozzles, and a reservoir for a cleaning liquid.

[0003] For accurate reproduction of a selected paint colour, particularly of small paint samples, small colorant volumes must be dispensed, e . g. , 0, 05 ml . To minimize margins of error, the nozzle should be clean, but also dry.

[0004] EP 3 711 868 Al discloses a tinting machine with a rotatable brush for cleaning the nozzles of the respective dispensers . The brush is cleaned with a cleaning liquid. The brush is then allowed to dry, and subsequently used for dry brushing the nozzle . After a number of cleaning cycles, the cleaning liquid is drained and the cleaning liquid reservoir is refilled with fresh and clean cleaning liquid. The used cleaning fluid is chemical waste and is difficult to dispose of properly.

[0005] It is an obj ect of the invention to provide a tinting machine with a more efficient nozzle cleaning system for providing clean and dry nozzles, with a more economic and sustainable use of cleaning liquid.

[0006] The obj ect of the invention is achieved with a tinting machine comprising a cleaning tool for cleaning the nozzles of the dispensers and a reservoir for holding a cleaning liquid with a supply line for transferring cleaning liquid from the cleaning liquid reservoir to the cleaningtool and a return line for collecting and recycling spent cleaning liquid from the cleaning tool .

[0007] This configuration makes it possible to remove the cleaning liquid reservoir without the need to displace other parts, e . g. , allowing easier removal of spent cleaning liquid and allowing replacement of a cleaning liquid reservoir with another one, or the same one, containing fresh cleaning liquid. The cleaning liquid reservoir can for example be re-leasably placeable in the nozzle cleaning unit, e . g. , without fasteners or mounting elements requiring the use of a tool, in particular if the cleaning liquid reservoir is at a distance from the cleaning tool, e . g. , at a distance below and / or next to the cleaning tool .

[0008] The cleaning liquid reservoir can for example be a disposable container, such as a bottle, e . g. , a plastic bottle . In that case, the containers can be collected and discharged to a waste collecting station for proper waste processing, destruction or recycling.

[0009] In a specific embodiment, the supply line has an inlet opening above a sediment level, i . e . , the maximum level sediment can reach before regular replacement of the cleaning liquid. For instance, the supply line has an inlet opening in the upper 80% of the cleaning liquid reservoir, e . g. , in the upper half of the cleaning liquid reservoir . During use, the cleaning liquid will be contaminated. Surprisingly, it was found that cleaning liquid saturated with removed colorant, is still just as effective with cleaning as fresh cleaning liquid. Oversaturation of the cleaning liquid with residual colorant results in settling of thedispersed contaminants . By positioning the inlet of the supply line in the upper half of the cleaning liquid reservoir, saturated cleaning liquid can still be used, while the sediment builds up until a certain level below the supply line inlet . This way, the same amount of cleaning liquid can be used for significantly more cleaning cycles .

[0010] To prevent direct recirculation from the outlet of the return line to the inlet of the supply line, the outlet opening of the return line can be arranged at a vertical distance from the inlet of the supply line . In this way, the returned cleaning liquid is given sufficient time with less turbulence to allow the colorant residues to settle .

[0011] The cleaning liquid reservoir can for example have a height H which is larger than its width W to allow for more distance between the bottom and the inlet of the supply line .

[0012] In a specific embodiment, the cleaning liquid reservoir has a top rim that is provided with a lid retention means, such as a threaded or snap-on rim, for a removable cap or lid. This allows the cleaning liquid reservoir to be safely closed after use and taken to a waste collection point .

[0013] The cleaning tool can for example comprise one or more rotatable brushes . Alternatively, or additionally, other cleaning tools can be used, such as a cloth or sponge . Optionally, the cleaning tool can be replaceable, e . g. , disposable .

[0014] In a specific embodiment, the supply line has a top end with a spray head or nozzle head directed to the cleaning tool, e . g. , over the full length of the rotatablebrush in a direction parallel to the rotating axis of the rotatable brush. Optionally, the cleaning unit may further comprise a pressure roller engaging the rotatable brush at a point downstream of the spray head, viewed in rotating direction of the rotatable brush. This way, the brush is dried directly after being wetted by the cleaning liquid upon rotation of the brush.

[0015] The cleaning liquid can for example be or comprise water, e . g. , comprising a soap, or an organic solvent, such as methanol, ethanol or acetone . Optionally, the cleaning liquid may contain a settling agent promoting settling of removed colorant residue .

[0016] The invention also pertains to a method of operating a tinting machine, optionally as described above, having a nozzle cleaning unit comprising a cleaning liquid reservoir for cleaning liquid, the cleaning liquid reservoir being replaced and disposed of after a period of time or after a number of cleaning cycles .

[0017] During use of the cleaning liquid reservoir, recycling of the cleaning liquid can be maintained after saturation of the cleaning liquid, e . g. , until a sediment layer of a predefined thickness has formed.

[0018] The invention is further explained with reference to the accompanying drawings showing an exemplary embodiment .

[0019] Figure 1 : shows a tinting machine with one side broken away to show its internals;

[0020] Figure 2 : shows an exemplary nozzle;Figure 3 : schematically shows a nozzle cleaning unit ;

[0021] Figure 4 : shows the cleaning tool of the cleaning unit of Figure 3 in side view;

[0022] Figure 5 : shows a disposable reservoir for a nozzle cleaning unit .

[0023] Figure 1 shows an exemplary embodiment of a tinting machine 1 for dispensing a plurality of colorant or pigment pastes for paints . In the drawing, one side is broken away to show the internals . The tinting machine 1 comprises a support 2 - in this embodiment a turntable - and a plurality of dispensers 3 mounted on the turntable 2. Each dispenser 3 comprises a container or canister 4 for holding an amount of a tinting paste, and a piston pump 5.

[0024] The piston pump 5 has a lower end connected to a valve 6, as is shown in more detail in Figure 2. The valve 6 comprises a valve housing 7 and a valve element 8 rotatably received in the valve housing 7 for selectively connecting the piston pump 5 to the container 4 during a suction stroke, and to a dispense outlet 9 of the dispenser 3 during a pressure stroke of the piston pump 5.

[0025] In the shown embodiment, the rotatable valve element 8 has two dispense channels of different diameter : a sample channel 10 for small dispenses, e . g. , 0, 05 ml or less, and a larger one . The dispense channels 10, 11 form a nozzle 12, 13 at the surface of the rotatable valve element 8. During dispense, the selected nozzle 12, 13 is aligned with the dispense outlet 9 of the valve housing 7.The tinting machine 1 further comprises a nozzle cleaning unit 14 to remove residual tinting paste left on the nozzle 12, 13 after a dispense cycle . The nozzle cleaning unit 14 is shown schematically in Figure 3. The nozzle cleaning unit 14 comprises a cleaning tool 15 for cleaning the nozzles 12, 13 of the dispensers 3, and a reservoir 16 for holding a cleaning liquid 17. In the shown embodiment, the cleaning tool 15 is a brush rotatable in a rotating direction R about a substantially horizontal rotating axis X .

[0026] By rotating the turntable 2, a selected one of the dispensers 3 can be positioned above the cleaning unit 14. In this position, the dry brush 15 engages the nozzle 12 -or one of the nozzles 12, 13 - of the valve element 7 and is rotated to brush the nozzle 12 clean.

[0027] A spray head 18 is positioned next to the top side of the brush 15 and directed to the brush 15, as shown in side view in Figure 4. The spray head 18 extends along the entire length of the brush 15 and is substantially parallel to the rotating axis X of the brush 15. A supply line 19, provided with a pump 20, fluidly connects the spray head 18 with the cleaning liquid reservoir 16. When the pump 20 is activated, cleaning liquid 17 is moved from the cleaning liquid reservoir 16 to the spray head 18 and sprayed onto the brush 15. By rotating the brush 15, the complete brush 15 is sprayed and cleaned.

[0028] The lower half of the brush 15 is positioned in a collection bin or funnel 21 with a bottom opening connecting to a discharge line 22 above the cleaning liquid reservoir 16. Cleaning liquid dripping from the brush 15 is collectedin the collection bin 21 and recycled to the cleaning liquid reservoir 16 via the discharge line 22.

[0029] A pressure roller 23 engages the lower half of the brush 15 at a point in the collection bin 21 at a distance from the lowest side of the brush 15. Viewed in the rotating direction R of the brush 15, the spray head 15 is downstream of the nozzle engaging top end of the brush 15, the lower end of the brush 15 is downstream of the spray head 18, and the pressure roller 23 is downstream of the lower end of the brush 15, but upstream of the top end of the brush 15. The pressure roller 23 extends along the full length of the brush 15 and is substantially parallel to the rotating axis X of the brush 15. The pressure roller 23 presses against the brush 15 to squeeze the cleaning fluid out of the brush 15 and accelerate drying of the brush 15. Alternatively or additionally, other drying tools, such as an air blower or fan, can also be used.

[0030] The cleaning liquid reservoir 16 is releasably placed in the tinting machine 1 below the brush 15 and the collection bin 21, in the sense that it can be removed by hand without an auxiliary tool . This way, the cleaning liquid reservoir is replaceable, allowing for example to use disposable cleaning liquid reservoirs .

[0031] A specific example of a cleaning liquid reservoir 16' is shown in Figure 5. In this embodiment, the cleaning liquid reservoir 16' is a transparent plastic bottle having height which is larger than its width or diameter . The cleaning liquid reservoir 16' has a threaded top rim 24 to make it closeable by a matching threaded cap (not shown) after use, so it can safely be removed for replacement .In Figure 5, the cleaning liquid contains a sediment 25 of settled tinting paste residues . The supply line 19 has an inlet opening 26 below liquid level, but well above the level of the sediment 25 of tinting paste residues . Since the sediment level may rise, the inlet opening 26 the supply line is preferably in the upper half of the cleaning liquid reservoir 16' .

[0032] Similarly, the discharge line 22 has a lower end 27 below liquid level, but above the sediment 25 in order not to disturb settlement of the tinting paste residues .

[0033] The cleaning liquid above the sediment can be recycled many times since it was found that saturated cleaning liquid cleans just as well as fresh cleaning liquid.

[0034] During cleaning, the brush is dry. After cleaning the nozzle, residual tinting paste needs to be removed from the brush and the pump of the supply line is activated to spray cleaning liquid from the spray head onto the brush, during rotation of the brush. When the brush is dry again, it can be used for a next cleaning cycle .

[0035] The brush can for example be cleaned by spraying for about 20 second while the brush makes one or more full rotations, and then be dried by rotating the brush for about 40 second without spraying. Other time intervals can also be used if so desired.

[0036] The brush can for example be cleaned at fixed times . For example, the brush can be cleaned every morning before opening time and / or every evening after closing time of the point of sale where the tinting machine is located. In a next step, the nozzles can be cleaned by the dry brush,one by one . Optionally, a nozzle can also be cleaned if a predefined maximum limit of dispenses is exceeded.

[0037] The disclosure is not restricted to the above described embodiment which can be varied in a number of ways within the scope of the claims .

Claims

CLAIMS1 . Tinting machine ( 1 ) for dispensing a plurality of colorant or pigment pastes for paints , comprising :- a support ( 2 ) ,- a plurality of dispensers ( 3 ) mounted on the support , each dispenser comprising a noz zle ( 12 , 13 ) ;- a cleaning tool ( 15 ) for cleaning the noz zles of the dispensers ,- a cleaning liquid reservoir ( 16 ) for holding a cleaning liquid with a supply line ( 19 ) for trans ferring cleaning liquid from the cleaning liquid reservoir ( 16 ) to the cleaning tool ;- a return line ( 22 ) for collecting and recycling spent cleaning liquid from the cleaning tool ( 15 ) .2 . Tinting machine according to claim 1 , wherein the cleaning liquid reservoir is at a distance from the cleaning tool ( 15 ) , e . g . , at a distance below the cleaning tool ( 15 ) .3 . Tinting machine according to claim 1 and 2 , wherein the supply line ( 19 ) has an inlet opening ( 26 ) in the upper 80% of the cleaning liquid reservoir ( 16 ) .4 . Tinting machine according to claim 1 , 2 or 3 , wherein the return line ( 22 ) has an outlet opening ( 27 ) at a vertical distance form the inlet opening ( 26 ) of the supply line ( 19 ) .

5. Tinting machine according to any one of the preceding claims, wherein the cleaning liquid reservoir ( 16) has a height which is larger than its width.

6. Tinting machine according to any one of the preceding claims, wherein the cleaning liquid reservoir ( 16) has a top rim (24 ) that is provided with a lid retention means, such as a threaded or snap-on rim, for a removable cap or lid.

7. Tinting machine according to any one of the preceding claims, wherein the cleaning tool ( 15) comprises a rotatable brush.

8. Tinting machine according to claim 7, wherein the supply line ( 19) has a top end with a spray head or nozzle head ( 18 ) directed to the rotatable brush ( 15) and wherein the tinting machine further comprises a pressure roller (23) engaging the rotatable brush at a point downstream of the spray head ( 18 ) , viewed in rotating direction R of the rotatable brush ( 15) .

9. Method of operating a tinting machine ( 1 ) comprising :- a support (2 ) , such as a turntable,- a plurality of dispensers (3) mounted on the support, each dispenser comprising a nozzle ( 12, 13) ;- a cleaning tool ( 15) for cleaning the nozzles of the dispensers ,- a cleaning liquid reservoir ( 16) for holding a cleaning liquid,wherein after some time or after a number of cleaning cycles, the cleaning fluid reservoir ( 16) is replaced with another, matching cleaning fluid reservoir ( 16) and disposed.

10. Method according to claim 9, wherein recycling of the cleaning liquid ( 17 ) is maintained after saturation of the cleaning liquid ( 17 ) , e . g. , until a sediment layer of a predefined thickness has formed.

11. Method according to claim 9 or 10, wherein the cleaning tool ( 15) is cleaned with the cleaning liquid, and subsequently dried before it is used to clean one or more nozzles ( 12 , 13 ) .

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