EP4043107A1

EP4043107A1 - Spray system with rotating cover

Info

Publication number: EP4043107A1
Application number: EP21156636.9A
Authority: EP
Inventors: Joacim WELLANDER
Original assignee: Imogo AB
Current assignee: Imogo AB
Priority date: 2021-02-11
Filing date: 2021-02-11
Publication date: 2022-08-17
Anticipated expiration: 2041-02-11
Also published as: EP4043107B1; WO2022171455A1

Abstract

A spray system (200) for applying a liquid to an object, comprising:a spray head (210) for ejecting the liquid;a cover (220), suspended in front of the spray head, wherein the cover has a curved surface (221) and an opening (222) for allowing the ejected liquid to pass through the cover in a spray application position of the cover,wherein the cover is rotatable to a cleaning position, wherein the spray head is arranged to eject a cleaning fluid onto the curved surface.

Description

Technical field

The solutions proposed in this disclosure relate to spray systems configured to eject a liquid. Specifically, solutions are provided for a spray system comprising a rotatable cover which can be set to different positions for use during spray application and during cleaning or priming of the spray system. The proposed solution is suitable for use in a spray application apparatus configured for spraying a liquid onto an object, such as for dyeing a textile material.

Background

Spray systems are frequently employed in different fields of application, for instance for the purpose of application of a liquid material onto an object. One example of such a field is the application of a liquid material onto a textile material. The purpose of the liquid application may be dyeing or finishing the textile material to provide the textile material with one or several preferred features. Some examples of preferred features are color, glaze, water-repellence, flame resistance, and softness.
One aspect of operation of spray systems is that various parts of the system may occasionally need to be cleaned or primed before use. This may for instance be suitable between spray application of a first liquid and spray application of a second liquid, such as liquids of different type or color. Such operation is time-consuming and may require particular operation of the spray system.

Summary

An object of the invention on which the solutions provided herein are based, is to increase efficiency of a spray systems configured for applying a liquid to an object. One aspect of this general object it to increase time efficiency for spray systems usable for application for different types of liquid. Another aspect of the general object is to minimize substance consumption in a spray system.
These objectives are targeted by the solution as set out in the independent claims. Various suitable embodiments are further outlined in the dependent claims.
According to a first aspect a spray system for applying a liquid to an object is provided, comprising:

a spray head for ejecting the liquid;
a cover, suspended in front of the spray head, wherein the cover has a curved surface and an opening for allowing the ejected liquid to pass through the cover in a spray application position of the cover,
wherein the cover is rotatable to a cleaning position, wherein the spray head is arranged to eject a cleaning fluid onto the curved surface.

In one embodiment, said opening is positioned at a low point of the curved surface, in said cleaning position, to allow the cleaning fluid to drain from the cover.
In one embodiment, the cover comprises a hollow cylinder body having a partial envelope wall which forms said curved surface.
In one embodiment, the partial envelope wall covers a range of 180-300 degrees about an axis of the cylinder body.
In one embodiment, the cover is suspended to rotate about an axis which extends horizontally in front of the spray head.
In one embodiment, the spray application position, the curved surface forms a gutter portion for redundant liquid.
In one embodiment, a recycling outlet is formed in connection with the gutter portion of the cover.
In one embodiment, a bottom wall of the gutter portion forms a chute, leading sideways to the recycling outlet arranged at an end portion of the cover.
In one embodiment, the recycling outlet is arranged to supply the redundant liquid to a liquid container.
In one embodiment, the spray head is connected to be supplied with liquid from said liquid container.
In one embodiment, the spray head comprises a plurality of nozzles, and wherein the opening comprises one or more slots aligned with said nozzles in the spray application position.
According to a second aspect, a spray application apparatus is provided, comprising:

at least one spray system according to the first aspect or any of the foregoing embodiments;
an object suspension mechanism, configured to suspend an object in the apparatus such that the cover is arranged between the spray head and the object.

In one embodiment, the object is a textile material, and wherein the object suspension mechanism comprises a set of rollers configured to convey the textile material past the spray system during liquid application.
According to a third aspect, a method for spraying a liquid onto an object is provided, comprising:

arranging the object facing a spray head for ejecting the liquid;
arranging a cover, suspended between the spray head and the object, in a spray application position, such that a curved surface of the cover faces the object;
ejecting liquid from the spray head through an opening in the cover towards the object;
rotating the cover to a cleaning position, wherein the object is covered from the spray head; and
ejecting a cleaning fluid from the spray head onto the curved surface.

In one embodiment, wherein said opening is positioned at a low point of the curved surface in said cleaning position, the method comprises:
draining the cleaning fluid from the cover through said opening.

Brief description of the drawings

The proposed solution and various embodiments thereof will be described in more detail below, with reference to the appended drawings showing example embodiments, wherein:

Fig. 1 schematically illustrates a spray application apparatus for spray application of a liquid onto a textile material;
Fig. 2 schematically illustrates a spray system comprising a rotatable cover arranged in a spray application position, wherein a spray head of the spray system is allowed to eject a liquid through the cover onto an object;
Fig. 3 schematically illustrates fluid communication to and from the spray system during spray application;
Fig. 4 schematically illustrates the spray system of Fig. 2 with the cover rotated to a cleaning or priming position, wherein a spray head of the spray system is arranged to eject a fluid onto the cover;
Fig. 5 schematically illustrates fluid communication to and from the spray system during cleaning or priming of the spray system;
Fig. 6 schematically shows a perspective view of the rotatable cover, for use in a spray system according to various embodiments;
Figs 7A and 7B schematically shows the relative arrangement of a spray head and the cover in the spray application position, in a spray system according to various embodiments;
Figs 8A and 8B schematically shows the relative arrangement of the spray head and the cover in the cleaning position, in a spray system according to various embodiments; and
Fig. 9 is a flow chart of a method for operating a spray application apparatus according to various embodiments.

Detailed description

In the following description, for purposes of explanation and not limitation, details are set forth related to various examples. However, it will be apparent to those skilled in the art that the present invention may be practiced in other examples that depart from these specific details. In some instances, detailed descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail. The drawings are to be regarded as being schematic representations, wherein elements illustrated in the drawings are not necessarily shown to scale. Rather, the various elements are represented such that their function and general purpose become apparent to a person skilled in the art. Any connection or coupling between functional blocks, devices, components, or other physical or functional units shown in the drawings or described herein may also be implemented by an indirect connection or coupling.
Fig. 1 schematically illustrates a spray application apparatus 100. It shall be noted that further elements and functions may be comprised in the apparatus 100 than those shown in the drawing, such as control systems and further liquid and cleaning fluid supply arrangements, as will at least in part be mentioned in the following. Fig. 1 is to be seen as a schematic representation of the spray application apparatus 100 in operation.
The spray application apparatus 100 comprises an object suspension mechanism 110, configured to suspend an object 105 in the apparatus. The spray application apparatus 100 may be configured to apply a liquid onto a surface of any type of object. The object suspension mechanism may thus comprise an arrangement for holding an object in the spray application apparatus, and optionally also for transporting the object in and out of the spray application apparatus. For the example provided in Fig. 1, and as primarily discussed herein, the spray application apparatus is configured to spray a liquid onto a textile material 105. Specifically, Fig. 1 illustrates a spray application apparatus 100 in which the textile material 105 is continuously or step-wise conveyed through the spray application apparatus, for the purpose of applying a liquid onto successive portions of the textile material 105. The suspension mechanism 110 may thus comprise a set of one or more rollers 112, 113, configured to convey the textile material 105 through the spray application apparatus 100. The textile material 105 may be supplied from a textile material source 120, such as a roll or a folded arrangement of the textile material 105. A motor mechanism 111 may be connected to drive the suspension mechanism to convey the textile material 105, such as by rotating one or more rollers 112.
The spray application apparatus further comprises one or more spray systems 200, which may be arranged to apply a liquid onto the object 105 held in the object suspension mechanism 110. In the shown example, the spray application apparatus 100 comprises four spray systems 200, with two spray systems 200 being arranged to face either of two opposing surfaces of the textile material 105. Other types of arrangements, with more or fewer spray systems 200, may be contemplated for the spray application apparatus 100. Liquid is taken from a liquid container 140 or other supply system and may be supplied to the spray system 200 by a spray pump 150. Textile material 105 onto which the liquid has been applied is transported away from the spray system 200 to a station 130 for further processing, such as drying.
The spray system 200 will now be described in further detail, and how it may be employed and operated in a spray application apparatus such as the spray application apparatus 100 of Fig. 1.
Fig. 2 schematically illustrates the spray system 200, arranged in a spray application mode. Supply of the liquid, such as by the spray pump 150, is left out for the sake of simplicity. However, a supply connection is typically arranged in the spray system 200, such as a hose or pipe connection for fluid communication with a liquid supply system.
The spray system 200 comprises a spray head 210 for ejecting the liquid. The spray head may comprise one or more nozzles 211, which may be selectively changed or configured to operate for ejecting a certain type of liquid in a desired spray pattern at a certain liquid pressure. The particular control and configuration of the spray head 210 is not as such relevant for the proposed solution and will not be discussed in any further detail. However, the spray head 210 is preferably configured to eject the liquid in a spray pattern which is at least partly diverging in at least one direction, as illustrated, so as to apply the ejected liquid over a surface portion, of the object 105, which is substantially larger than the nozzle 211 output.
The spray system 200 further comprises a cover 220, suspended in front of the spray head 210. Fig. 2 illustrates the cover in a spray application position, at which the cover 220 has a curved surface 221 on a side of the cover facing away from the spray head 210. The curved surface thus at least partly faces the object 105. An opening 222 is provided in the cover 220 for allowing the ejected liquid to pass through the cover 220 towards the object 105. The cover 220 serves inter alia the purpose of preventing spray liquid from landing on the spray head 210 and other parts of the spray system 200, from e.g. aerosol formation or splashing from the object 105. This is particularly relevant in a spray application apparatus 100 as illustrated in Fig. 1, wherein oppositely directed spray systems 200 are mounted. In such an arrangement, liquid ejected from one spray system 200 which passes beside or even through the object 105 is prone to contaminate the opposing spray system 200. The cover 220 thus minimizes the need for exterior cleaning of the spray system 200.
In the spray application position, the curved surface 221 of the cover 220 further serves the purpose of collecting liquid droplets that may spread in the air from the ejected liquid or which may splash from the object 105. This way, residual liquid is taken care of, and is at the same time prevented from landing on other unintended parts of the object 105 and on other parts of a spray application apparatus 100. The residual liquid collected by the cover 220 may be taken care of and be reused, so as to minimize liquid consumption.
Fig. 3 schematically illustrates a pair of spray systems 200 in connection with a liquid supply system 300. In the spray application mode, as also shown in Fig. 2, the spray head 210 of the spray system 200 is supplied with a first liquid 310 by operation of one or more spray pumps 150 to pump the first liquid 210 through a conduit 151, comprising one or more hoses or pipes, from a liquid tank 140, such as a buffer tank. A benefit of using a buffer tank 140 for the spray system is that a recycling arrangement can be obtained, whereas at the same time a comparatively small volume may need cleaning or priming before use with a different liquid. The buffer tank 140 may, in a spray apparatus set up for textile application, have a volume which is substantially less than the total volume to be supplied in a textile application process. The buffer tank 140 may thus continuously, or repetitively, be supplied with a liquid during a spraying process. In some embodiments, the buffer tank may have a volume of a few liters, such as 3-10 liters. The buffer tank 140 may be supplied with the liquid 310 from a first liquid source 141, by gravity or other supply mechanism, such as a pump 170. The first liquid source 141 may e.g. be a dye supply source.
In various embodiments, the curved surface 221 of the cover forms a gutter portion 223 for redundant liquid, as best seen in Fig. 2. This way, droplets emanating from the ejected spray, or splashing off of the object 105, may be collected in the gutter portion 223. It may be noted that the cover 220 may be arranged at a desired distance from the object 105, which may entail positioning the cover 220 as close as possible to the object 105 without risking connection, so as to increase the capability of collecting redundant or residual liquid. The gutter portion 223 may be formed by an upward bend of the cover 220 at its lower edge, as illustrated in Fig. 2.
In various embodiments, a recycling outlet 224 is formed in connection with the gutter portion 223 of the cover 200, as indicated in Fig. 3. This will be further described below. As indicated in Fig. 3, the recycling outlet 224 may be arranged to supply the collected redundant or residual liquid back to the buffer tank 140, e.g. by means of gravity and a connection 225 of hoses or pipes. This way, a liquid recycling system is obtained, which minimizes liquid consumption or waste.
Once a process of liquid application is performed, the spray system may require cleaning. This may typically be the case after a spray application process is completed, and the spray system 200 is subsequently to be used with a different liquid. This may be the case when changing to a completely different type of liquid, such as changing from a dye to an impregnation fluid or a flammability resistance liquid, or for instance when changing dye from one color to another color. In this scenario, the spray head 210 and its fluid connection, such as various hoses or pipes, typically need to be cleaned or changed. Cleaning or changing of the spray system 200 is a time-consuming process that may have a negative effect on overall process time.
In view of this problem, a solution is proposed herewith that the cover 220 is arranged to be rotatable to a cleaning position, wherein the spray head 210 is arranged to eject a cleaning fluid onto the curved surface 221. This is illustrated in Figs 4 and 5.
In Fig. 4, the cover 220 has been rotated to the cleaning position, wherein the spray system 200 is arranged in a cleaning mode. Preferably, rotation is carried out clockwise from the perspective of Figs 2 to Fig. 4, such that a trailing edge of the cover 200 is moved down to below the nozzle 211 of the spray head 210. Herein, the surface 221 of the cover that was directed towards the object 105 in the spray application position, now at least partly faces the spray head 210. At the same time, the cover shields the object 105 from being exposed to liquid, e.g. a cleaning fluid, ejected by the spray head 210. By means of this rotatable arrangement, the spray system may be conveniently cleaned by supplying the spray head 210 with a cleaning fluid to rinse the supply system and the nozzle 211 from any residue of the first used liquid. Specifically, cleaning of the spray system 200 may be carried out without removing the object 105. This way, unwanted extension of overall processing time may be avoided. The cleaning fluid is typically selected based on the character of the liquid used to spray the object, such as water or another solvent.
Advantageously, the cover 220 may be rotated such that the spray head 210 faces the gutter portion 223. This way, the cleaning fluid ejected from the spray head 210 may, at the same time as cleaning the nozzle 211 and the fluid supply system, operate to clean the cover from residue of the first liquid.
In various embodiments, assuming the cleaning position of the cover 220 entails positioning the opening 222, which is used to allow liquid to pass through the cover in the spray application position, at a low point of the curved surface 221. This way, the cleaning fluid which is ejected from the spray head 210 onto the wall 221 of the cover 220 is allowed to drain from the cover 220. Using the same opening 222 for two different purposes allows for a low complexity design of the cover 220.
Fig. 5 illustrates the overall layout corresponding to Fig. 3, but in the cleaning mode. This scenario involves arranging the cover 220 in the cleaning position. Cleaning may comprise draining the buffer tank 140, such as by connecting an outlet 142 to a drain. The buffer tank 140 is then connected to be filled with a cleaning fluid 510. In some embodiments, a separate pump may be used for this purpose. In various embodiments, though, the cleaning fluid 510 may be provided into the buffer tank 140 from a cleaning fluid supply source 160, by using the feed pump 170. The process of draining and filling up the buffer tank 140 with the cleaning fluid may be repeated, to successively dilute and discharge any liquid, used in a preceding spray application process, remaining in the buffer tank 140.
The cleaning fluid 510 is thereafter pumped from the buffer tank 140 by the same spray pump 150 as used for the liquid in the spray application mode. This way, the buffer tank 140, the conduit 151 and the pump 150 connecting the buffer tank 140 to the spray head 210, and the spray head 210 itself, are all rinsed during cleaning. In this process, the pumped cleaning fluid may first be drained from the spray head 210 through a separate drain outlet 212. This process may be carried out for a predetermined time, such as 3-10s, determined such that the supply system, from the spray pump 150 through the 151 conduit to the spray head 210, is deemed to be properly rinsed dependent on the pump pressure provided by the spray pump 150.
The cleaning steps outlined above may be carried out prior to arranging the cover 220 into the cleaning position. For the next cleaning step, though, the cover 220 is arranged in the cleaning position of Figs 4 and 5. This cleaning step comprises pumping cleaning fluid through the nozzle 211 to clean the latter. This may be carried out for a preset time, such as less than 10s. In a variant of the embodiment shown in Fig. 5, at least this cleaning step, involving ejecting the cleaning fluid through the nozzle 211, may be carried out by connecting to a general water supply system, such as a faucet outlet.
In the step of cleaning the nozzle 211, the ejected cleaning fluid 510 is moreover used to clean the cover 220, and specifically the wall portion 221 which otherwise faces the object 105 in the spray application mode. This is accomplished since, in the cleaning position, the nozzle 211 is directed to eject the cleaning fluid onto the wall 211 of the cover 220. The cleaning fluid is then allowed to drain from the cover 220, through the opening 222, into a drain 180, possibly with a connecting drain conduit 181.
Once the cleaning process is completed, the buffer tank 140 may subsequently be supplied with a new liquid, such as a second liquid 320 (not shown) which is different from the first liquid and provided from a different liquid source (not shown) than the first liquid 310. The second liquid 320 may e.g. be a dye of a different color than the first liquid 310. By rotating the cover 220 back to the spray application position, the spray system 200 is again ready for spray application. Such rotation back is preferably carried out counter-clockwise as seen in the views from Fig. 4 back to the spray application position of Fig. 2.
In some embodiments, a priming step may be carried out after cleaning, prior to spray application using a liquid, such as the second liquid 320. Again, this priming step may be carried out while the object 105, e.g. a textile fabric, remains suspended in the spray apparatus 100. The priming step may comprise supplying the liquid to use after cleaning, such as the second liquid 320, to the buffer tank 140, e.g. after draining the cleaning fluid from the buffer tank 140. The liquid 320, possibly partly mixed with remaining cleaning fluid from the buffer tank 140, is thereafter pumped by the spray pump 150 through the conduit 151 to the spray head 210, and the through the spray head 210 itself, for draining through the outlet 212. This process may be carried out for a predetermined time, such as 3-10s, determined such that the supply system, from the spray pump 150 through the 151 conduit to the spray head 210, is deemed to be properly primed with the second liquid 320. The priming steps outlined above may be carried out with the cover in the active position. However, the cover 220 is at least arranged in the cleaning position of Figs 4 and 5 in the subsequent priming step, which involves pumping second liquid 320 through the nozzle 211 to for a certain preset time, such as a few seconds. In this step, a small amount of the second liquid 320 is discharged from the nozzle 210 towards the wall 221 of the cover 220, which prevents the liquid to reach the object 105. The liquid 320 is then allowed to drain through the opening 222.
Fig. 6 schematically shows a perspective view of an embodiment of the cover 220. The cover 220 comprises a hollow cylinder body having a partial envelope wall 226 which forms said curved surface 221 on its inner side. The cover 220 may further comprise end walls 227. In the drawing examples shown herein, the cross-section of the cover 220 is substantially circular. It should be noted, though that the wall forming the curved surface 221 can have other shapes, such as an elliptic or a polygon cross section. A suspension member 228, such as a protruding tap, may be used for rotatably attaching the cover 220 in the spray system 200, in relation to the spray head 210. Thereby, the cover 220 is arranged to be rotatable about a rotation axis 60.
The partial envelope wall 226 may cover a range of 160-300 degrees about the rotation axis 60 of the cylinder body, such as in the range of 180-250 degrees. This way, the cover may provide the function of the gutter portion 223 in the spray application position, while at the same time suitably cover an upper portion of the spray system 200 from contamination. In addition, after rotating about 90 degrees, such as between 80 and 100 degrees, to the cleaning position, the trailing edge of the cover 200 closest to the spray head 210 may be arranged to just below the nozzle 211. Exact dimensions of the cover may be suitably configured dependent on various parameters, such as distance to the object 105 position and vertical spray angle.
The example of the cover 220 shown in Fig. 6 is usable in a spray system 200 in conjunction with a spray head 210 which comprises a nozzle manifold, i.e. a plurality of nozzles 211. For this purpose, the opening 222 may comprise one or more slots 222-1 to 222-4, configured to be aligned with a plurality of nozzles 211 of the nozzle manifold in the spray application position.
Figs 7A and 7B show various details of an embodiment of the spray system 200, comprising a cover 220 in accordance with Fig. 6.
The cover 220 is rotatably suspended by its suspension member 228 to a frame portion 71 of the spray system 200. The spray head 210 is in turn connected to the frame portion 71. The spray head 210 has an elongated shape and comprises a plurality of nozzles distributed along the length of the spray head 210. The cover 220 is suspended to rotate about an axis 60 (see Fig. 6) which extends horizontally in front of the spray head 210. The axis need not be strictly horizontal but has at least a horizontal component.
In the spray application mode of Figs 7A and 7B, the gutter portion 223 of the cover is located at a bottom position of the cover 220. The recycling outlet 224 is formed in connection with the gutter portion 223 of the cover 220. In the shown embodiment, the recycling outlet 224 is formed in at least one end wall 227 of the cylinder body of the cover 220. In an alternative embodiment, the recycling outlet 224 is formed in the curved wall 226 of the cover 220.
In some embodiments, as indicated in Figs 7A and 7B, a bottom wall part of the gutter portion 223 forms a chute 229, inclined to lead redundant and collected fluid sideways to the recycling outlet 224 arranged at an end portion of the cover 220. This way, collection and removal of redundant fluid for recycling to the spray system 200 is improved, by minimizing the risk of curing and clogging of the fluid in the gutter portion 223 of the cover 220. The recycling outlet 224 is in turn arranged to supply the redundant liquid to a liquid container, such as the buffer tank 140, from which the spray head 210 is fed. The chute 229 may be in some embodiments formed by a strip-shaped sheet, of e.g. metal or plastic with an increasing width, attached along the inner surface 221 of the cover 220, as is shown in the drawings. In an alternative embodiment, the entire spray system 200 may be inclined to a certain degree, down towards the recycling outlet.
Figs 8A and 8B show the same embodiment as Figs 7A and 7B, but in the cleaning mode, wherein the cover 220 has been rotated to the cleaning position, which may also be employed for priming. The spray head 210 is thereby arranged to eject a cleaning fluid towards the curved surface 221 of the cover 220, and specifically the gutter portion. In the perspective view of Fig. 8B, the plurality of nozzles 211 are visible on the spray head 210. The cleaning fluid is drained from the cover 220 through the openings 221-1 to 221-4.
Fig. 9 shows a flow chart of a method for operating a spray application apparatus, such as the apparatus 100 of Fig. 1, for spraying a liquid onto an object 105. In one embodiment, the object 105 is a textile material, which is conveyed through the spray application apparatus, past one or more spray systems 200 as outlined herein.
The method starts at step 900.
In step 910, the object is arranged to face a spray head 210 of a spray system 200, for ejecting the liquid. In an apparatus comprising multiple spray systems, the object may be suspended to be conveyed between opposite spray systems, configured to eject fluid onto opposing surfaces of the object 105. In some embodiments, such opposing spray systems may be controlled to concurrently eject the same liquid onto the respective surfaces of the object 105. Alternatively, the opposing spray systems may be controlled to eject or different liquids, such as different types of liquid or dyes of different color.
In step 920, the cover, which is suspended between the spray head 210 and the object 105, is arranged in a spray application position, such that the curved surface 221 of the cover 220 faces the object 105.
In step 930, liquid is ejected, i.e. sprayed, from the spray head 210 through an opening 222 in the cover 220 towards the object 105, such that the liquid is applied to the object 105 in a distributed manner. The object 105 may be successively conveyed past the spray system 200 so as to apply the liquid to an extended portion of the object 105.
In step 940, once application of the liquid is terminated, the cover 220 is rotated to a cleaning position, wherein the object 105 is covered from the spray head 210 by means of the cover 200.
In step 950, a cleaning fluid is ejected from the spray head 210 onto the curved 221 of the cover, so as to simultaneously clean the spray head 221 and the cover 220. In some embodiments, this step 950 is carried out without removing the object 105.
In step 960, which is comprised in some embodiments, the cleaning fluid is drained from the cover 220 through said opening 222 during cleaning, by means of said opening 222 being positioned at a low point of the curved surface 221 in said cleaning position.
The method as described may in various embodiments be conveniently used when shifting between application of a first liquid, succeeded by application of a second liquid, such as different types of liquids or different colors of a dye liquid. The first and second liquids may be applied to the same object, and even to the same surface portion of the object 105, or to different objects 105 or to different surface portions of the object 105. In such embodiments, the method may comprise one or more of steps 925, 970 and 980.
In step 925, a first liquid is supplied to the spray head 210. This step may optionally be carried out prior to or between steps 910 and 920. This first liquid is subsequently ejected in step 930.
In step 970, carried out after cleaning of the spray system 200 in step 950, a second liquid may be supplied to the spray system 220, to prime the system before spray application with the second liquid. head 210. This may include discharging an amount of the second liquid from the spray head towards the cover, which is arranged in the cleaning position to shield the object 105.
In step 980, the cover 200 is rotated back to the spray application position, and the second liquid is supplied to the spray head. The method then proceeds to step 930, wherein the second fluid is ejected from the spray system 200.
The process ends at 990, preferably after cleaning step 950 or 960.
pIn the foregoing, various embodiments and advantageous effects of the proposed solution have been outlined. Except where clearly contradictory, the features and functions of the described embodiments may be combined in any way. The invention underlying the proposed solution is only limited by the appended claims.

Claims

A spray system (200) for applying a liquid to an object, comprising:
a spray head (210) for ejecting the liquid;

a cover (220), suspended in front of the spray head, wherein the cover has a curved surface (221) and an opening (222) for allowing the ejected liquid to pass through the cover in a spray application position of the cover,

wherein the cover is rotatable to a cleaning position, wherein the spray head is arranged to eject a cleaning fluid onto the curved surface.
The spray system of claim 1, wherein, in said cleaning position, said opening (222) is positioned at a low point of the curved surface to allow the cleaning fluid to drain from the cover.
The spray system of claim 1 or 2, wherein the cover comprises a hollow cylinder body having a partial envelope wall (226) which forms said curved surface.
The spray system of claim 3, wherein the partial envelope wall covers a range of 180-300 degrees about an axis (60) of the cylinder body.
The spray system of any preceding claim, wherein the cover is suspended to rotate about an axis (60) which extends horizontally in front of the spray head.
The spray system of any preceding claim, wherein, in the spray application position, the curved surface forms a gutter portion (223) for redundant liquid.
The spray system of claim 6, wherein a recycling outlet (224) is formed in connection with the gutter portion of the cover.
The spray system of claim 7, wherein a bottom wall of the gutter portion forms a chute (229), leading sideways to the recycling outlet (224) arranged at an end portion of the cover.
The spray system of claim 7 or 8, wherein the recycling outlet (224) is arranged to supply (225) the redundant liquid to a liquid container (140).
The spray system of claim 9, wherein the spray head is connected (151) to be supplied with liquid from said liquid container (140).
The spray system of any preceding claim, wherein the spray head comprises a plurality of nozzles (211), and wherein the opening comprises one or more slots (222-1, 222-2) aligned with said nozzles in the spray application position.
A spray application apparatus (100) comprising:
at least one spray system (200) according to any of the preceding claims;

an object suspension mechanism (110), configured to suspend an object (105) in the apparatus such that the cover is arranged between the spray head and the object.
The spray application apparatus of claim 12, wherein the object is a textile material (105), and wherein the object suspension mechanism comprises a set of rollers (112, 113) configured to convey the textile material past the spray system (200) during liquid application.
A method for spraying a liquid onto an object, comprising:
arranging (910) the object facing a spray head for ejecting the liquid;

arranging (920) a cover, suspended between the spray head and the object, in a spray application position, such that a curved surface of the cover faces the object;

ejecting (930) liquid from the spray head through an opening in the cover towards the object;

rotating (940) the cover to a cleaning position, wherein the object is covered from the spray head; and

ejecting (950) a cleaning fluid from the spray head onto the curved surface.
The method of claim 14, wherein said opening is positioned at a low point of the curved surface in said cleaning position, wherein the method comprises:
draining (960) the cleaning fluid from the cover through said opening.