A water outlet device comprising an outlet element

Abstract

The present disclosure provides a water outlet device comprising an inlet for receiving water, a flow path extending from the inlet and defining a downstream direction towards an outlet, and an outlet element forming an opening for dispensing water in an axial direction. The opening forms at least one sidewall arranged such that water is in contact with at least one contact surface portion of the at least one sidewall during dispensing of water. The at least one contact surface portion is formed by black oxidized copper.

Description

[0001] A WATER OUTLET DEVICE COMPRISING AN OUTLET ELEMENT

[0002] Field of the disclosure

[0003] The present disclosure relates to a water outlet device comprising an outlet element forming an opening for dispensing water, to an outlet element, to a method of manufacturing an outlet element, and to the use of the water outlet device and the outlet element for reduction of retrograde contamination.

[0004] Background of the disclosure

[0005] Although water pipes may be cleaned, for example by flushing, such cleaning is often inefficient as bacteria in the water typically grow to form a biofilm adhering strongly to, and covering large areas of, the pipe interior. Harmful pathogens within the biofilm include bacteria of the Legionella genus which cause Legionellosis in the form of pneumonia (Legionnaires' disease) and other respiratory illnesses (Pontiac fever). The bacteria Legionella pneumophila is responsible for over 90% of the Legionellosis cases, and 90% of the Legionella bacteria in the pipe is found within the biofilm. Other contaminants in the water include as an example the parasites Giardia duodenalis and Cryptosporidum and the bacteria Mycobacterium avium. Filters may be arranged in water installations to decrease the risk of such contamination.

[0006] However, contamination may also occur from outside the water pipes, such as when the water outlet devices (water taps, shower heads, etc.) come in contact with pathogens, such as Pseudomonas aeruginosa, from a person touching the water outlet device or by backsplashing of water, e.g. when a person is washing hands. Ag ions are used to inhibit bacteria growth in water installation. However, Ag ions may be unwanted in relation to drinking water.

[0007] Description of the disclosure

[0008] It is an object of embodiments of the disclosure to provide an improved water outlet device.

[0009] It is a further object of embodiment of the disclosure to provide an improved outlet element.

[0010] It is an even further object of embodiment of the disclosure to provide a method of manufacturing an outlet element. According to a first aspect, the disclosure provides a water outlet device comprising an inlet for receiving water, a flow path extending from the inlet and defining a downstream direction towards an outlet, and an outlet element forming an opening for dispensing water in an axial direction, wherein the opening forms at least one sidewall arranged such that water is in contact with at least one contact surface portion of the at least one sidewall during dispensing of water, and wherein the at least one contact surface portion is formed by black oxidized copper. The black oxidized copper surface portion may have an average roughness Ra below 500 nm.

[0011] By providing the outlet element with a contact surface portion formed by black oxidized copper, the average roughness Ra may be low, such as below 500 nm and the antibacterial properties of the outlet element are improved. The black oxidized copper material may prevent, or at least considerably reduce the risk of bacterial growth at the water outlet device, particularly at the outlet element. Additionally, the low roughness may limit the risk of bacteria and / or other contaminants being fixed to the outlet element. The low roughness may further facilitate efficient cleaning of the outlet element.

[0012] The at least one contact surface portion may be formed by black oxidized copper with an average roughness Ra below 500 nm, or even lower, such as below 350 nm, such as below 200 nm, such as below 100 nm. The average roughness Ra is defined as the integer mean of all absolute roughness profile deviations from the centre line within the measurement length.

[0013] The water outlet device may be a water tap, a hand shower, or another water installation for dispensing water. The water outlet device comprises a water inlet for receiving water, and an inner flow path extending from the inlet and defining a downstream direction towards the outlet, the flow path being configured for providing a flow of water from the water inlet to the outlet element forming an opening for dispensing water.

[0014] The outlet element may be a separate element which may be attached to the water outlet device or to a part hereof. Alternatively, the outlet element may be formed integrally with the water outlet device or with a part hereof.

[0015] The outlet element forms an opening for dispensing water in an axial direction. By the term dispensing water in an axial direction should be understood that the predominant direction of water dispensed via the opening is the axial direction. It should, however, also be understood that the flow of water when dispensed need not be shaped as a cylinder, as the flow of water may be wider at a distance from the opening than at the opening. The opening forms at least one sidewall arranged such that water is in contact with at least one contact surface portion of the at least one sidewall during dispensing of water. The at least one sidewall may extend substantially along the flow direction of water being dispensed from the opening. As an example, the sidewall may extend circumferentially around the opening. In one embodiment, the contact surface portion may substantially be the entire sidewall, whereby substantially the entire sidewall may have a surface formed by black oxidized copper which may have an average roughness Ra below 500 nm or even lower, such as below 350 nm, such as below 200 nm, such as below 100 nm.

[0016] The at least one contact surface portion may additionally have a peak to valley average roughness Rz below 2500 nm, such as below 2000 nm, such as below 1500 nm, such as below 800 nm, where the average roughness Rz is the absolute peak to valley average of five sequential sampling lengths within the measuring length.

[0017] The outlet element may in one embodiment be formed by a plastic material, e.g. formed by moulding, where at least a part of the outlet element may be copper plated, which copper is black oxidized to provide the at least one contact surface portion formed by black oxidized copper which may have an average roughness Ra below 500 nm or even lower, such as below 350 nm, such as below 200 nm, such as below 100 nm. In one embodiment, the entire surface of the outlet element may be copper plated, where the copper may be black oxidized.

[0018] As an alternative to an outlet element formed by plastic, where at least a part of the surface is copper plated, and where the contact surface portion is formed by black oxidized copper, the outlet element may be a solid copper element, where at least the contact surface portion is formed by black oxidized copper.

[0019] The at least one contact surface portion may be formed by black oxidized copper which may be obtained by a chemical oxidation process. The chemical oxidizing process may use an aqueous mixture comprising selenious acid (FhSeOs) and hydrogen chloride (HCI) as active ingredients as well as further additive, such as another acid and / or tensides to oxidize the copper surface to CuO which may provide a uniform, black surface with maintained antimicrobial properties; i.e., the antimicrobial properties of the copper material may be maintained substantially unamended after chemically oxidizing the copper. As a further alternative, the black oxidized may be obtained by thermal passivation.

[0020] By black oxidizing the copper surface by a chemical oxidization process using selenious acid (FhSeOs) and hydrogen chloride (HCI), the contact surface portion may be chemically stable. It may further have the advantage that the contact surface portion does not turn green in time, while at the same time keeping the roughness low to thereby limit the risk of bacteria and / or other contaminants being fixed to the outlet element and to facilitate efficient cleaning of the contact surface portion.

[0021] The chemical oxidation process using an aqueous mixture comprising selenious acid and hydrogen chloride may be carried out by dipping the outlet element in the mixture. Consequently, substantially the entire surface of the outlet element may be black oxidized. The outlet element may as an example be manufactured by moulding the outlet element of plastic (e.g. ABS (Acrylonitrile Butadiene Styrene), MBS (Methyl methacrylate Butadiene Styrene), POM (Polyoximethylene), or another plastic material). The outlet element may subsequently be copper coated. The copper coated outlet element may be dipped into an aqueous mixture comprising selenious acid and hydrogen chloride to thereby provide an outlet element with a surface of black oxidized copper. The copper coated outlet element having a surface of black oxidized copper may be rinsed with water and dried with hot air.

[0022] The chemical black oxidizing process has a further advantage, that a binding agent is not needed. A binding agent is typically necessary if using a paint comprising copper.

[0023] If an outlet element formed by a plastic material alternatively is painted with paint comprising copper to add antimicrobial properties to the outlet element, tests show that the roughness of the copper surface would be significantly higher thereby increasing the risk of fixing bacteria and / or other contaminants to the outlet element, while also increasing the need for cleaning. The use of a paint with copper particles further has the disadvantage that the copper particles are detached over time and released to the water. Additionally, a paint with copper particles typically needs a post painting processing, such as grinding or milling, to ensure there are copper particles in the outer surface layer of the painting and not only copper particles covered by the binding agent of the paint.

[0024] The below table, Table 1, illustrates measured roughness, Ra and Rn, of a contact surface portion of an outlet element formed by a plastic material, where the outlet element is 1) standard white plastic material without copper, 2) plastic material, copper plated and black oxidized, and 3) plastic material, painted with a copper containing paint. The measurements are carried out in accordance with ISO 4287.

[0025] Table 1 : Comparison of measured roughness of a contact surface portion of different outlet elements.

[0026] The outlet element may form a plurality of passages extending along the axial direction, whereby water may be dispensed through the plurality of passages together forming the opening. By dividing the opening into a plurality of passages, the area of the contact surface portion may be increased. This may additionally provide a laminar flow of the water being dispended through the opening.

[0027] As an example, at least a plurality of the passages may be formed as substantially circular holes. In one embodiment, each of the passages may be substantially circular holes. In an alternative embodiment, at least some of the passages may be formed as substantially rectangular holes, such as an array of substantially rectangular holes. In other embodiments, the passages may form other shapes. It should be understood that different shapes may be combined in alternative embodiments.

[0028] As a further example, the at least one sidewall may form a millwheel shape to thereby provide a plurality of passages. A plurality of sidewalls may extend from a centre point of the opening toward the circumference of the opening to provide the plurality of passages which may be of the same size. In one embodiment the millwheel shape may form a plurality of sidewalls extending from an inner ring-shaped sidewall forming a central passage towards the circumference of the opening. Both the inner ring-shaped sidewall and the circumference of the opening may be sidewalls forming contact surface portions.

[0029] An opening area transverse to the axial direction of each of the passages may be below 25 mm2, such as below 20 mm2, such as below 15 mm2. These small passages in combination with the height of the sidewalls may increase contact between bacteria and / or other contaminants to thereby increase the antimicrobial properties of the contact surface portion. The height of the sidewall(s) may be defined as the dimension of the sidewall(s) in the axial direction. The height of the sidewall(s) may be in the range of 5-25 mm, such as in the range of 5-15 mm. The outlet element may comprise a centre portion defined by the at least one sidewall and the opening, and peripheral portion encircling the centre portion. The peripheral portion may extend in the axial direction and terminate in a free end. As the peripheral portion may encircle the centre portion and thus the at least one sidewall and the opening, the peripheral portion may protect the opening by reducing the risk of backsplashing into the opening. The peripheral portion may further reduce the risk of a person touching the opening during use of the water outlet device, e.g. when washing his / her hands.

[0030] A first distance of the peripheral portion along the axial direction from the free end to the opening may be at least 1 mm, such as 1.5 mm, such as 2 mm or even more. The first distance may depend on the size of the opening.

[0031] The first distance relative to an inner diameter of the peripheral portion may be in the range of 5-15%, where the inner diameter of the peripheral portion is the size of the opening perpendicular to the axial direction. It should be understood that the opening may be circular, oval, or of another shape. In an embodiment, where the opening is not circular, the diameter should be understood as the largest dimension of the opening.

[0032] An outer diameter of the peripheral portion may decrease towards the free end to narrow down the peripheral opening formed by the peripheral portion, as this may increase the protection of the opening by the peripheral portion. This may further facilitate that water drops slashing towards the outer surface of the peripheral portion may run of along the outer surface of the peripheral portion.

[0033] The peripheral portion may be formed integrally with the remaining parts of the outlet element. Thus, in one embodiment the outlet element with the peripheral portion may be formed by a plastic element, where at least a part hereof may be copper plated, which copper plated part may be black oxidized. In one embodiment, substantially the entire outlet element with the peripheral portion may be copper plated and subsequently black oxidized.

[0034] The outlet element may be removably attached to the water outlet device. This may allow for replacement of an outlet element or detachment of the outlet element for cleaning hereof.

[0035] The water outlet device may further comprise a filter configured for filtration of water before water is dispensed via the opening. The filter may be arranged inside the water outlet device, such as in the inner flow path upstream the outlet element, e.g. inside a hand shower or inside a water tap. The filter may comprise a membrane which as an example may comprise polyethersulfone, polysulfone, polyvinylidene difluoride, cellulose acetate, or polyethylene hollow fibre membranes. Other types of membranes may also be used. To provide a membrane of sterilizing grade type, the pore sizes of the membrane may be up to 0.2 pm. The hollow fibres may be fixated by a potting material which may be capable of separating the contaminated water from the filtered water.

[0036] According to a second aspect, the disclosure provides an outlet element forming an opening for dispensing water in an axial direction, wherein the opening forms at least one sidewall arranged such that water is in contact with at least one contact surface portion of the at least one sidewall during dispensing of water, and wherein the at least one contact surface portion comprising black oxidized copper. The black oxidized copper surface may have an average roughness Ra below 500 nm or even lower, such as below 350 nm, such as below 200 nm, such as below 100 nm.

[0037] The outlet element may as an example be manufactured by moulding the outlet element of plastic. The outlet element may subsequently be copper coated. The copper coating may be obtained by a copper plating process, which as an example may comprise the following steps: Cleaning the moulded plastic surface using a cleaning agent solution, etching the surface using phosphoric acid, reduction using hydrogen peroxide, pre-dipping using hydrochloric acid, activation using stannous chloride, nickel plating using nickel sulphate, and copper plating using copper sulphate.

[0038] The copper coated outlet element may be dipped into an aqueous mixture comprising selenious acid and hydrogen chloride to thereby provide an outlet element with a surface of black oxidized copper. Thus, in one embodiment, the entire surface of the outlet element may be copper plated, where the copper may be black oxidized. The black oxidized copper surface may be obtained by a chemical oxidation process, e.g. by using an aqueous mixture comprising selenious acid (l-hSeOs) and hydrogen chloride (HCI).

[0039] It should be understood that a skilled person would readily recognise that any feature described in combination with the first aspect of the disclosure could also be combined with the second aspect of the disclosure, and vice versa.

[0040] According to a third aspect, the disclosure provides a method of manufacturing an outlet element according to the second aspect for a water outlet device comprising an inlet for receiving water, where a flow path extends from the inlet and defines a downstream direction towards an outlet, the method comprising the steps of:

[0041] - moulding the outlet element of a plastic material;

[0042] - copper plating at least a part of the outlet element; and - oxidizing the copper to form a black oxidized copper contact surface portion.

[0043] The oxidizing step forms a black oxidized surface which may have an average roughness Ra below 500 nm, such as below 350 nm, such as below 200 nm, such as below 100 nm.

[0044] The step of black oxidizing the copper may e.g. be formed by use an aqueous mixture comprising selenious acid and hydrogen chloride to oxidize the copper surface to CuO. This may provide a uniform, black surface with maintained antimicrobial properties.

[0045] It should be understood that a skilled person would readily recognise that any feature described in combination with the first and second aspects of the disclosure could also be combined with the third aspect of the disclosure, and vice versa.

[0046] The method steps according to the third aspect of the disclosure are very suitable for manufacturing an outlet element according to the second aspect of the disclosure and for the water outlet device according to the first aspect of the disclosure. The remarks set forth above in relation to the water outlet device and the outlet element are therefore equally applicable in relation to the method.

[0047] According to a fourth aspect, the disclosure provides the use of an outlet element according to the second aspect in a water outlet device comprising an inlet for receiving water, where a flow path extends from the inlet and defines a downstream direction towards an outlet for reduction of retrograde contamination of water flowing through the opening.

[0048] It should be understood that a skilled person would readily recognise that any feature described in combination with the first, second, and third aspects of the disclosure could also be combined with the fourth aspect of the disclosure, and vice versa.

[0049] According to a fifth aspect, the disclosure provides a method of reducing retrograde contamination, the method comprising the steps of:

[0050] - providing a water outlet device comprising an inlet for receiving water, a flow path extending from the inlet and defining a downstream direction towards an outlet, and an outlet element forming an opening for dispensing water in an axial direction, wherein the opening forms at least one sidewall arranged such that water is in contact with at least one contact surface portion of the at least one sidewall during dispensing of water, and wherein the at least one contact surface portion is formed by black oxidized copper; - disposing water on the contact surface portion;

[0051] - reducing bacterial growth by the black oxidized copper to reduce retrograde contamination.

[0052] The black oxidized contact surface portion may have an average roughness Ra below 500 nm, such as below 350 nm, such as below 200 nm, such as below 100 nm.

[0053] It should be understood that a skilled person would readily recognise that any feature described in combination with the first, second, third, and fourth aspects of the disclosure could also be combined with the fifth aspect of the disclosure, and vice versa.

[0054] Brief description of the drawings

[0055] Embodiments of the disclosure will now be further described with reference to the drawings, in which:

[0056] Fig. 1 schematically illustrates an embodiment of a water outlet device;

[0057] Fig. 2 illustrates an embodiment of an outlet element; and

[0058] Figs. 3A-3C illustrate different views of the outlet element in Fig. 2.

[0059] Detailed ion of the

[0060] It should be understood that the detailed description and specific examples, while indicating embodiments of the disclosure, are given by way of illustration only, since various changes and modifications within the scope of the disclosure will become apparent to those skilled in the art from this detailed description.

[0061] Fig. 1 schematically illustrates a water outlet device 1 in the form of a water tap. The water outlet device 1 comprises an inlet for receiving water 2, and a flow path 4 extending from the inlet and defining a downstream direction towards an outlet 6. The flow path 4 is schematically illustrated by the dotted line. The water outlet device 1 further comprises an outlet element 8 forming an opening 10 for dispensing water in an axial direction X. The outlet element 8 is illustrated in more details in Figs. 2 and 3A-3C. In the illustrated embodiment, the water outlet device 1 comprises a handle 12 for opening and closing the water. It should be understood that the water outlet device 1 in an alternative embodiment may be without a handle. As an example, the water outlet device may instead comprise a sensor, where opening and closing of the water may be in response to a sensed signal, such as in response to moving hands.

[0062] In the illustrated embodiment, the water outlet device 1 further comprises a filter 14 configured for filtration of water before water is dispensed via the opening 10. The filter 14 is arranged inside the water outlet device 1 upstream the outlet element 8. The filter 14 is schematically illustrated and may comprise a membrane (not shown) which as an example may comprise poly-sulfone hollow fibres.

[0063] Fig. 2 and Figs. 3A-3C illustrate different views of an outlet element 8 forming an opening 10 for dispensing water. Fig. 3A illustrates the outlet element 8 from below, Fig. 3B is a cross- sectional view of the outlet element 8, and Fig. 3C is a side-view of the outlet element 8. In the illustrated embodiment, the opening forms a plurality of sidewalls 16, 16A, 16B arranged such that water is in contact with at least one contact surface portion 16' of the sidewalls during dispensing of water. The at least one contact surface portion 16' is formed by black oxidized copper which may have an average roughness Ra below 500 nm, such as below 350 nm, such as below 200 nm, such as below 100 nm.

[0064] In the illustrated embodiment, the outlet element 8 is formed by a plastic material where the entire surface is copper plated. Subsequently, the copper has been black oxidized. As the entire surface of the outlet element 8 is copped plated and black oxidized, the contact surface portion 16' of each of the sidewalls 16 is formed by the entire sidewall 16.

[0065] The plurality of sidewalls 16 forms a millwheel shape to thereby provide a plurality of passages 18, where the passages 18 together form the opening 10 for dispensing water. The plurality of sidewalls 16 extend from an inner ring-shaped sidewall 16A forming a central passage 18A towards the circumference 16B of the opening 10. Both the inner ring-shaped sidewall 16A and the circumference of the opening 16B are sidewalls 16 forming contact surface portions 16' of black oxidized copper.

[0066] The outlet element 8 comprise a centre portion 20 being defined by the sidewalls 16, 16A, 16B and the opening 10, and peripheral portion 22 encircling the centre portion 20. The peripheral portion 22 extends in the axial direction X and terminates in a free end 24. As the peripheral portion 22 encircles the centre portion 20 and thus the sidewalls and the opening 10, the peripheral portion 22 can protect the opening 10 by reducing the risk of backsplashing into the opening 10. The peripheral portion 22 further reduces the risk of a person touching the opening 10. In the illustrated embodiment, the centre portion 20 is formed integrally with the remaining parts of the outlet element 8, whereby the centre portion 20 is also covered by black oxidized copper.

Claims

CLAIMS1. A water outlet device comprising an inlet for receiving water, a flow path extending from the inlet and defining a downstream direction towards an outlet, and an outlet element forming an opening for dispensing water in an axial direction, wherein the opening forms at least one sidewall arranged such that water is in contact with at least one contact surface portion of the at least one sidewall during dispensing of water, and wherein the at least one contact surface portion is formed by black oxidized copper.

2. The water outlet device according to claim 1, wherein the at least one contact surface has an average roughness Ra below 500 nm.

3. The water outlet device according to claim 1 or 2, wherein the at least one contact surface portion has a peak to valley average roughness Rz below 2500 nm.

4. The water outlet device according to any of the preceding claims, wherein the at least one contact surface portion formed by black oxidized copper is obtainable by chemical oxidization using selenious acid and hydrogen chloride.

5. The water outlet device according to any of the preceding claims, wherein the outlet element forms a plurality of passages extending along the axial direction.

6. The water outlet device according to claim 5, wherein at least a plurality of the passages is formed as substantially circular holes.

7. The water outlet device according to claim 6, wherein the sidewalls form a millwheel shape.

8. The water outlet device according to any of claims 5-7, wherein an opening area transverse to the axial direction of each of the passages is below 25 mm2.

9. The water outlet device according to any of the preceding claims, wherein the outlet element comprises a centre portion defined by the at least one sidewall and the opening and peripheral portion encircling the centre portion, the peripheral portion extending in the axial direction and terminating in a free end.

10. The water outlet device according to claim 9, wherein a first distance along the axial direction of the peripheral portion from the free end to the opening is at least 1 mm.

11. The water outlet device according to claim 10, wherein the first distance relative to an inner diameter of the peripheral portion is in the range of 5-15%.

12. The water outlet device according to any of claims 10-11, wherein an outer diameter of the peripheral portion decreases towards the free end.

13. The water outlet device according to any of the preceding claims, wherein the outlet element is formed by a plastic material, where at least a part of the outlet element is copper plated, the copper being black oxidized.

14. The water outlet device according to claims 9 and 13, wherein the peripheral portion is formed integrally with the remaining parts of the outlet element.

15. The water outlet device according to claim 13 or 14, wherein outlet element is fully copper plated, the copper being black oxidized.

16. The water outlet device according to any of the preceding claims, wherein the outlet element is removably attached to the water outlet device.

17. The water outlet device according to any of the preceding claims, further comprising a filter configured for filtration of water, the filter being arranged in the flow path upstream the outlet element.

18. An outlet element forming an opening for dispensing water in an axial direction, wherein the opening forms at least one sidewall arranged such that water is in contact with at least one contact surface portion of the at least one sidewall during dispensing of water, and wherein the at least one contact surface portion is formed by black oxidized copper.

19. The outlet element according to claim 18, wherein the at least one contact portion has an average roughness Ra below 500 nm.

20. A method of manufacturing an outlet element according to claim 18 for a water outlet device comprising an inlet for receiving water, a flow path extending from the inlet and defining a downstream direction towards an outlet, the method comprising the steps of:- moulding the outlet element of a plastic material;- copper plating at least a part of the outlet element; and14- oxidizing the copper to form a black oxidized copper contact surface portion.

21. The method according to claim 20, wherein the oxidizing step forms a black oxidized surface with an average roughness Ra below 500 nm.

22. The method according to claim 20 or 21, wherein the step of oxidizing the copper is formed as a chemical oxidizing step using selenious acid and hydrogen chloride.

23. Use of an outlet element according to claim 18 in a water outlet device comprising an inlet for receiving water, a flow path extending from the inlet and defining a downstream direction towards an outlet for reduction of retrograde contamination of water flowing through the opening.

24. A method of reducing retrograde contamination, the method comprising the steps of:- providing a water outlet device comprising an inlet for receiving water, a flow path extending from the inlet and defining a downstream direction towards an outlet, and an outlet element forming an opening for dispensing water in an axial direction, wherein the opening forms at least one sidewall arranged such that water is in contact with at least one contact surface portion of the at least one sidewall during dispensing of water, and wherein the at least one contact surface portion is formed by black oxidized copper;- disposing water on the contact surface portion;- reducing bacterial growth by the black oxidized copper to reduce retrograde contamination.

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