GB2611062A

GB2611062A - A UV-C room disinfection device

Info

Publication number: GB2611062A
Application number: GB2113659.3A
Authority: GB
Inventors: Williams Tristan
Original assignee: Finsen Tech Ltd
Current assignee: Finsen Tech Ltd
Priority date: 2021-09-24
Filing date: 2021-09-24
Publication date: 2023-03-29
Also published as: GB202113659D0

Abstract

A UV-C room disinfection device 1 for disinfecting room surfaces, the device comprising a set of UV-C light sources 9 and a set of polytetrafluoroethylene (PTFE) comprising reflectors (19, Fig. 4) adjacent the UV-C light sources 9, configured to reflect light emitted from the UV-C light sources 9. The reflectors (19) may comprise a reflector body and a PTFE layer, which may be sintered PTFE (S-PTFE), disposed on an outer surface (23, Fig. 7a), with an adhesive layer between the PTFE layer and the reflector body. The device 1 may be transportable, comprising one or more wheels 12. A reflector configured to be the reflector of the disinfection device 1 is defined, and a method of manufacturing a reflector for use in the disinfection device 1, comprising forming a reflector body and applying a PTFE layer to the outer surface (23) of the body. The PTFE layer may be applied via an adhesive tape (30, Fig. 10) comprising the PTFE layer. Also described is a UV-C room disinfection tower comprising an upstanding set of PTFE coated reflectors coated arranged inside an upstanding set of UV-C light sources, the reflectors arranged to reflect light emitted by the UV-C light sources.

Description

A UV-C ROOM DISINFECTION DEVICE

Field of the Invention

The present invention concerns UV-C room disinfection devices The present invention also concerns UV-C room disinfection devices comprising reflectors. The invention also concerns reflectors for such devices, and methods of manufacturing such reflectors

Background of the Invention

UV-C room disinfection devices emit UV-C radiation into a treatment area, for example a room. It will be appreciated that treatment areas encompass different types of space which may require disinfection, and that in addition to conventional "rooms-, a room disinfection device can also be used to disinfect hallways, lobbies, landings, and any other enclosed or partially enclosed spaces comprising surfaces to be disinfected. All such spaces are taken to be rooms for the purposes of the present disclosure. UV-C room disinfection devices are used in a variety of settings, including gyms, dental surgeries and hospitals.

UV-C room disinfection devices operate by irradiating the boundary surfaces of the treatment area over a defined period of time. The devices tend to be transportable for intermittent use, as and when required. The devices can be extendible, so that they can be transported in a compact configuration, and extended to a greater height to enable floor to ceiling disinfection of the room to be treated.

UV-C room disinfection devices typically utilise a variety of mechanisms to ensure an adequate disinfection of the treatment area is carried out. For example, EP3468623B1 discloses a method of calculating an exposure time for disinfecting a room using an ultraviolet disinfecting apparatus. The method comprises the steps of measuring distances by: using a spatial sensor on the ultraviolet disinfecting apparatus, to perform a first scan of a boundary surface of the room, to measure a first set of distances from the sensor to the boundary surface; adjusting the height or orientation of the spatial sensor; using the spatial sensor to perform a second scan of the boundary surface of the room, to measure a second set of distances from the -2 -adjusted sensor to the boundary surface; and subsequently, calculating the exposure time in dependence on the sets of distances UV-C radiation will be understood to be ultraviolet radiation having a wavelength between 200-280nm, for example between 250-280nm.

Improvements to existing UV-C room disinfection device designs are sought, for example, to improve the efficiency and/or effectiveness of the disinfection process

Summary of the Invention

In a first aspect of the invention, there is provided a UV-C room disinfection device according to claim I. That inventors have realised that the use of polytetrafluoroethylene (PTFE) in UV-C room disinfection devices is highly advantageous. In room sterilisation applications, irradiation follows an inverse-square law. Consequently, for rooms of moderate to large size, a longer treatment time is required to ensure that an adequate dose is delivered to the room boundary surfaces. PTFE-based substances are generally non-reactive and have a variety of applications for example in non-stick coatings for cookware, in linings for corrosive chemical containers, in electronics and in surgical grafts. The inventors have recognised that reflectors comprising PTFE provide considerably improved reflectivity of incident UV-C light. PTFE exhibits both high reflectivity and diffuse reflectance, giving a uniform Lambertian distribution of light. As such, the device of the present invention enables more efficient disinfection of a treatment area, utilising less energy and/or requiring less time to deliver a required dose of UV-C radiation. There is reduced wasteful absorption of UV-C light into the materials of the device itself (i.e. the reflectors). In addition, PTFE is particularly resistant to UV-C degradation.

The UV-C emitters may be configured to emit ultraviolet light at a wavelength in the range 240-280nm. The UV-C emitters may be configured to emit ultraviolet light at a wavelength in the range 250-255nm. The UV-C emitters may be configured to emit ultraviolet light at a wavelength of 253.7nm. PTFE exhibits particularly good reflectivity properties in the wavelength range above 240nm. -3 -

For present purposes, a set will be understood to mean one or more". The sets of UV-C light sources and reflectors may be of the same, or different, sizes. There may be two light sources for every one reflector. The light sources may be identical to one another. The reflectors may have different shapes depending on their location on the device. The reflectors may be diffuser-reflectors i.e. being designed to both reflect and diffuse UV-C light. The reflectors may be formed from aluminium. The reflectors may comprise a reflector body and a PTFE layer disposed on an outer surface of the reflector body. "Outer surface" will be understood to mean a surface facing towards the treatment area when the reflector is installed on the device.

The outer surface may be anodised. The PTFE layer may cover substantially all of the outer surface. The PTFE layer may cover a portion of the outer surface.

The outer surface of the reflector body may comprise contours, wherein the PTFE layer conforms to the contours. Such contours may maximise the diffusion of UV-C light into the treatment area. Contours will be understood to be distortions of the surface. In other words, the outer surface may be non-planar.

The PTFE layer may have a thickness in the range 0.4-0.6mm, for example 0.5mm. Advantageously, this can provide an optimal balance between flexibility to ensure adhesion to the contoured outer surface of the reflector body whilst also providing enhanced reflectivity.

The reflector body may be elongate. The contours may comprise curved portions, for example extending along a length of the reflector body. Curved portions may provide a convex surface from which incident UV-C radiation is reflected in a diffuse pattern.

The set of reflectors may comprise a first group of reflectors having a first shape, and a second group of reflectors having a second shape. The first group of reflectors may be associated with a lower unit of the device. The second group of reflectors may be associated with an upper unit of the device.

The outer surface of the reflector body may comprise a flat portion between the curved portions The reflectors may comprise an adhesive layer between the PTFE layer and the outer surface of the reflector body.

The adhesive layer may have a thickness between 0.7-1.3mm, for example 1.0mm. The ratio of the thicknesses of the PTFE layer to adhesive layer may be -4 -approximately 1:2, for example the PTFE layer may have a thickness of 0.5mm and the adhesive layer may have a thickness of 1.0mm. In other words, the PTFE layer may be twice as thick as the adhesive layer. Such a ratio has been found to optimise adhesion of the PTFE to the reflector panel whilst preserving the contoured "waveform" profiles of the reflector panels and providing enhanced reflectivity.

The PTFE layer may have a substantially uniform thickness. The adhesive layer may have a substantially uniform thickness. As such, a consistent improved reflectivity may be enabled across the entire treatment area.

The PTFE may be solid PTFE. The PTFE may advantageously for improved reflectivity, be porous PTFE. The PTFE may be sintered polytetrafluoroethylene (S-PTFE). Sintering will be understood to be a method of fusing particles together by heat/pressure to form a porous solid. Sintering is particularly advantageous because it enables control of the resulting pore size and volume. Alternatively, the PTFE may be processed in another way, for example pressed or stretched.

The device may be transportable, for example comprising a base including one or more wheels. The device may be extendible.

The device may be a tower having a substantially cylindrical shape defining a central longitudinal axis, wherein the set of reflectors is arranged concentrically inside of the set of UV-C light sources with respect to the central longitudinal axis.

In a second aspect of the invention, there is provided a reflector according to claim 12.

In a third aspect of the invention, there is provided a method of manufacturing the reflector of the second aspect according to claim 13. The step of forming a reflector body may include extruding the reflector body.

The step of forming a reflector body may include the step of anodising the outer surface of the reflector body.

The step of applying a polytetrafluoroethylene (PTFE) layer to an outer surface of the reflector body may comprise: providing an adhesive tape comprising a PTFE layer; and applying the adhesive tape onto the outer surface of the reflector 30 body.

In a fourth aspect of the invention, there is provided a UV-C room disinfection tower according to claim 16 -5 -It will of course be appreciated that features described in relation to one aspect of the present invention may be incorporated into other aspects of the present invention. For example, the method of the invention may incorporate any of the features described with reference to the apparatus of the invention and vice versa.

Description of the Drawings

An embodiment of the present invention will now be described by way of example only with reference to the accompanying schematic drawings of which: Figure t is a side view of a UV-C disinfection device according to the example embodiment of the invention; Figure 2 is a perspective view of the device of Figure 1; Figure 3a is a schematic representation of the device of Figure 1 in an un-extended position; Figure 3b is a schematic representation of the device of Figure 1 in an extended position; Figure 4 is a schematic representation of the layout of the reflector panels of the device of Figure]; Figure 5 is a bottom view of the device of Figure 1; Figure 6 is a top view of the device of Figure 1; Figure 7a is a perspective view of a static reflector of the device of Figure 1; Figure 7b is an end view of the static reflector of Figure 7a; Figure 7c is a top view of the static reflector of Figure 7a (i.e. the outwards-facing side of the reflector, when in place in the device); Figure 7d is a close-up cross-section across B-B of the static reflector of Figure 7c; Figure 7e is a rear view of the static reflector of Figure 7a (i.e. the inwards-facing side of the reflector, when in place in the device); Figure 8a is a perspective view of a static back reflector of the device of Figure 1; Figure 8b is an end view of the static back reflector of Figure 8a; Figure Sc is a top view of the moving reflector of Figure 8a (i.e. the outwards-facing side of the reflector, when in place in the device); Figure 9a is a perspective view of a moving reflector of the device of Figure 1; -6 -Figure 9b is an end view of the moving reflector of Figure 9a, Figure 9c is a top view of the moving reflector of Figure 9a (i.e. the outwards-facing side of the reflector, when in place in the device); and Figure 10 shows a roll of tape according, to the example embodiment of the invention.

Detailed Description

A UV-C disinfection device 1 according to the example embodiment of the invention (Figures 1 and 2) is generally upright when positioned ready for use. The device comprises a body 3, extending in a longitudinal direction (with respect to a central longitudinal axis x of the device 1). The device 1 further comprises a bottom plate 5 and a sensor head 7 arranged on opposing lower and upper ends respectively of the body 3.

The body 3 comprises a lower unit 2 and an upper unit 4 (Figures 3a, 3b), the upper unit 4 being slidably movable in a direction parallel to the central longitudinal axis x of the device 1 with respect to the lower unit 2 from an un-extended configuration 14 (Figures 1, 2, 3a) to an extended configuration 16 (Figure 3b).

Details of the actuation mechanism for extending and retracting the device are known in the art, for example as described in EP2496271B 1. The units (2, 4) are in concentric arrangement with respect to the central longitudinal axis x of the device 1, the upper unit 4 disposed radially inside the lower unit 2. The default position is the un-extended configuration 14, since in this configuration, the device 1 is compact for storage and transportation. The device 1 is transportable, so that it can be moved into, and out of an area to be disinfected. h) the present example embodiment, the device is supported on a plurality of castor wheel assemblies 12 so that it can be moved along the ground. In the un-extended configuration device is approximately 1.1m in height, such that the device can be moved through a doorway of standard size. In the extended configuration device is approximately 2.25m in height, to reach all surfaces (at all heights) in the treatment area. Since the device 1 is intended for use in environments in which humans are present (such as hospitals and cinemas), it is configured to run discrete disinfection cycles. In the example embodiment, the device -7 - 1 is configured to be remotely controlled by a user operating a tablet in communication with the sensor head 7.

The device 1 further comprises a handrail assembly 11 comprising a handrail 13, two brackets 17 and a plurality of arms 15 between the handrail 13 and the body 3 of the device 1. The handrail 13 is positioned at a height to be accessible to a person standing adjacent the device 1. In the example embodiment, the handrail 13 is fixed to the static reflector-diffuser panels I 9a by brackets 17, and supported by arms IS which adjoin the static reflector-diffuser panels 19a and static back panels 19b and maintain the handrail 13 in a generally horizontal position. The handrail 13 provides a handhold to enable an operator to push the device 1 on the castor wheels 12.

The device 1 further comprises a plurality of UV-C tube bulbs 9. Twelve bulbs are located on the lower unit 2, and twelve bulbs are located on the upper unit 4. On each unit, the bulbs are arranged in pairs, with one bulb of each pair stacked vertically above the other bulb of each pair (i.e. extending in a direction parallel to the central longitudinal axis, x, between the bottom plate 5 and the sensor head 7). On each unit, there are six vertically stacked pairs of bulbs, arranged around the circumference of each unit.

Behind each pair of bulbs 9 is mounted a corresponding reflector-diffuser panel (19a, 19c) in longitudinal and circumferential alignment. The reflector-diffuser panels are situated behind the UV-C bulbs 9 (i.e. closer to the central longitudinal axis x of the device 1) in order to reflect and diffuse UV-C radiation which is directed towards them back out into the treatment area, away from the device 1 thereby maximising the level and coverage of UV-C exposure in the treatment area.

The lower unit 2 comprises six static reflector-diffuser panels 19a arranged around the circumference of the device 1, interspaced with six static back panels 19b (Figure 4). The upper unit 4 comprises six moving reflector-diffuser panels 19c. The six static back panels 19b act as guide tubes for the six moving reflector-diffuser panels 19c, which slot into the static back panels 19b. In the un-extended configuration 14, the moving reflector-diffuser panels 19c rest within the static back panels 19b. As the device 1 moves towards the extended configuration 16, the moving reflector-diffuser panels 19c slide with respect to the static back panels 19b in a direction parallel to the central longitudinal axis x of the device 1, taking with them -8 -the associated six pairs of bulbs 9. Thus in the extended position, there are two tiers of reflector-diffuser panels and associated bulbs.

The static reflector-diffuser panels 19a are joined to adjacent static back panels 19b along the long edges of the respective reflector-diffuser panels (as will be described in more detail herein), to form a continuous structure around the perimeter of the device 1 (i.e. making up the lower unit 2).

Viewed from below, the castor wheel assemblies are disposed around the circumference of the device 1 (Figure 5). The body 3 is centrally positioned on the bottom plate 5.

Viewed from above (Figure 6) it can be seen that the arms 15 of the handrail assembly are arranged in pairs, two pairs located on either side of the brackets 17. The UV-C bulbs 9 and associated reflector-diffuser panels (19a, 19c) are disposed in a circular arrangement, positioned side-by-side around the body 3 of the device 1. Adjacent the UV-C tube bulbs 9 are a plurality of associated ballasts (not shown), for example, one per bulb. As will be appreciated, the device 1 further comprises a system electronics module and a linear actuator (neither shown) for raising the upper unit of the device 1. The device 1 may also include an inner support frame (not shown) on which the various components are mounted.

The static reflector-diffuser panels 19a (Figures 7a-7e) are elongate, and are approximately the same length as the UV-C tubes 9. In the example embodiment, the static retlector-diffuser panels 19a have outer dimensions comprising a length of -1100mm, a width of -60mm, and a maximum depth of -14mm. The static reflector-diffuser panels 19a have a substantially flat, rectangular, inner surface 21 (i.e. facing inwards towards the central longitudinal axis of the device in use) and an opposing profiled (i.e. contoured) outer surface 23 (i.e. facing out towards the treatment area).

The static back panels 19b (Figures 8a-8c) are elongate, and are approximately the same length as the UV-C tubes 9. In the example embodiment, the static back panels 19b have outer dimensions comprising a length of -1100mm, a width of -105mm, and a maximum depth of -14mm. The static back panels 19b have an inner surface 21' (i.e. facing inwards towards the central longitudinal axis of the device in use) and an opposing profiled (i.e. contoured) outer surface 23' (i.e. facing out towards the treatment area). Each static back panel 19b comprises three sections along its width: a central section 31 and two contoured sections 33, on either side of -9 -the central section 31. The central section 31 comprises a flat elongate surface extending along the full length of the static back panels 19b. The contoured sections 33 comprise curved elongate ridges extending out of the flat surface 31 of the static back panels 19b in a direction away from the device and towards the treatment area, and along the full length of the static back panels 19b.

On the device 1, the static reflector-diffuser panels 19a are interspaced circumferentially between successive static back panels I 9b. Consecutive static reflector-diffuser panels and static back panels are positioned side-by-side with long edges inter-locking, such that all of the profiled outer surfaces (23, 23') face out into the treatment area, and all of the inner surfaces (21, 21') face towards the central longitudinal axis x of the device 1. The static back panels 19b comprise, along each longitudinal edge, a splayed end portion 30, which fits into a corresponding recessed end portion 27 of the static reflector-diffuser panels 19a.

The static reflector-diffuser panels 19a (referring back to Figures. 7c-7g) comprise a plurality of mounting holes 25 for receiving fasteners for attaching the static reflector-diffuser panels 19a to the UV-C bulbs. In the example embodiment, eight mounting holes are located together in a group midway along the length of the static reflector-diffuser panel 19a, whilst another four mounting holes 25 are spaced along a notional centre line running longitudinally along the static reflector-diffuser panel 19a.

The profiled surface 23 of the static reflector-diffuser panel 19a comprises, adjacent the recessed ends 27, a curved wing 25 on either side of the notional longitudinal centre line of the static reflector-diffuser panel 19a. The wings 25 curve inwards towards the notional longitudinal centre line of the static reflector-diffuser panel 19a. The wings 25 each provide a convex surface facing the treatment area from which incoming light rays from the UV-C bulbs 9 are reflected in a diffuse pattern, to maximise the distribution of UV-C light into the treatment area.

The static reflector-diffuser panel 19a is formed of extruded aluminium. The outer surface 23 comprises a matt anodised coating, for example a silver anodised coating. The anodisation of the outer surface 23 of the static relector panel 19a produces an adhesive-ready surface. As will be described in more detail herein, deposited on the anodised surface 23 is a layer of sintered polytetratluoroethylene, (SPTFE). The S-PTFE layer covers substantially all of the outer surface 23 of the static -10 -reflector-diffuser panel 19a. The S-PTFE layer is contiguous with the outer surface of the static reflector-diffuser panel 19a, preserving the shape of the wings 25 and remainder of the static reflector-diffuser panel 19a. In the example embodiment, the S-PTFE layer is 0.5mm thick, and is deposited on the outer surface 23 of the static reflector-diffuser panel 19a using an adhesive tape 30. In another embodiment, the S-PTFE layer may be applied in another way.

The moving reflector-diffuser panels 19c (Figs. 9a to 9d) are elongate, and are approximately the same length as the UV-C tubes 9. In the example embodiment, the moving reflector-diffuser panels 19c have outer dimensions comprising a length of -1100mm, a width of -100mm, and a maximum depth of -12mm. The moving reflector-diffuser panels 19c comprise a slightly curved outer surface 23" (i.e. facing inwards towards the central longitudinal axis of the device in use) and an opposing profiled (i.e. contoured) inner surface 21" (i.e. facing out towards the treatment area in use). The inner surface 21" is shaped to complement the shape of the outer surface 23' of the static back reflector 19b. The outer surface 23" of the moving reflector-diffuser panel 19c is curved at each longitudinal edge, providing two elongate concave surface regions 29 along opposing edges of the moving reflector-diffuser panel 19c facing out towards the treatment area to reflect UV-C light in a diffuse pattern.

On the device 1, the moving reflector-diffuser panels 19c are spaced around the circumference of the upper unit 4, and fixed to the actuator and/or an internal frame of the device 1 at either longitudinal end. Each moving reflector-diffuser panel is associated with a pair of vertically stacked (i.e. longitudinally stacked) bulbs 9. All of the curved outer surfaces 23-face out into the treatment area, and all of the inner surfaces 21" face towards the central longitudinal axis x of the device. The moving reflector-diffuser panels 19c are arranged concentrically inside the static reflector-diffuser panels 19a and static back panels 19b. Each moving reflector-diffuser panel 19c is positioned directly behind (i.e. radially inwards of) an associated pair of the UV-C tube bulbs 9.

The moving reflector-diffuser panels 19c comprise a plurality of mounting holes 25" for receiving fasteners for attaching the reflector-diffuser panels to the UV-C bulbs 9. In the example embodiment, eight mounting holes are located together in a group midway along the length of the reflector-diffuser panel 19b, whilst another four mounting holes are spaced along a notional centre line running longitudinally along the reflector-diffuser panel.

The moving reflector-diffuser panels 19c are formed of extruded aluminium. The outer surface 23" comprises a matt anodised coating, for example a silver anodised coating. The anodisation of the outer surface 23" of each moving reflector-diffuser panel 19c produces an adhesive-ready surface. Disposed on the anodised surface 23' is a layer of sintered polytetrafluoroethylene, (S-PTFE). The S-PTFE layer covers substantially all of the outer surface 23-of the moving reflector-diffuser panel 19c. The S-PTFE layer is contiguous with the outer surface of the moving reflector-diffuser panel 19c, preserving the curved shape. In the example embodiment, the S-PTFE layer is 0.5mm thick, and is fixed to the outer surface of the moving reflector-diffuser panel 19c using an adhesive tape 30.

The adhesive tape 30 (Figure 10) used to apply the S-PTFE to the reflector-diffuser panels has a width of 103mm, 66mm, 47mm and/or 20mm, and is applied in strips. The tape 30 is flexible, so that it can conform to surfaces having different waveform" profiles. The tape 30 comprises three layers: a bottom layer 35, a middle layer 37, and a top layer 39. The bottom layer 35 is formed of S-PTFE of thickness 0.5mm. The middle layer 37 of the tape is an adhesive, of thickness 1.0mm. The ratio of S-PTFE thickness to adhesive thickness of 1:2 has been found to be optimal for enabling the tape to successfully follow the profile of the complex contoured outer surfaces of the reflector-diffuser panels (19a, 19c) whilst still sticking securely to the panels and providing enhanced reflectivity. The top layer 39 of the tape 30 is a paper liner which covers the adhesive layer 37 and is discarded after the tape 30 is adhered to the reflector-diffuser panels (19a, 19c). To apply the S-PTFE to the reflector-diffuser panels (19a, 19c), the paper liner 39 is peeled off from the tape, leaving the adhesive layer 37 exposed. The adhesive layer 37 is pressed onto the anodised outer surface (23, 23") of the reflector-diffuser panels (19a, 19c), providing an S-PTFE coating on the anodised outer surfaces. The anodisation process has been found to improve the adhesion of the adhesive to the outer surface (23, 23") of the reflector-diffuser panels (19a, 19c). The S-PTFE layer 35 advantageously increases the reflectivity of UV-C light from the reflector-diffuser panels (19a, 19c).

Each stacked UV-C tube pair is aligned longitudinally and circumferentially with a corresponding reflector-diffuser panel (19a, 19c). Each reflector-diffuser panel -12 - (19a, 19c) is positioned directly behind (i.e. radially inwards of) the associated pair of UV-C tube bulbs. In another embodiment there may be one, or several, UV-C bulbs per reflector-diffuser panel, or vice versa. The reflector-diffuser panels (19a, 19c) provide a reflective and diffusive surface behind (i.e. radially inwards of) the UV-C tubes 9, to reflect and diffuse UV-C light emitted onto them during use back into the treatment area. The reflector-diffuser panels (19a, 19c) also provide a barrier to protect the system electronics module located within the device I from UV-C damage. The reflector-diffuser panels (19a, 19c) have a dual function, providing both reflection and diffusion of the UV-C light emitted by the UV-C tubes 9. The reflection and diffusion is enhanced by the contouring of the outer surfaces (23, 23") of the reflector-diffuser panels (19a, 19c) and further by the incorporation of an S-PTFE layer which optimises the reflection of UV-C light. The inventors have found that the benefits are especially pronounced at a wavelength of -253.7nm. At this wavelength, the S-PTFE layer has been found to improve the UV-C reflectivity from the UV-C disinfection device 1 to -97%. In addition, S-PTFE has been found to be the optimum form of PFTE for providing a sufficient tensile strength along with durability for day to day operation of the device 1.

Whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein. By way of example only, certain possible variations will now be described.

In a further example embodiment, there may be only one unit i.e. the device is not extendible. In a further example embodiment, there may be three or more extending units.

In a further example embodiment, the reflectors may be all of the same type.

In a further example embodiment, there may be more than two differently profiled reflector-diffuser panels.

Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, -3 -convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments.

Claims

-14 -Claims 1. A UV-C room disinfection device for disinfecting surfaces of a room, the device comprising: a set of UV-C light sources, and a set of reflectors adjacent the set of UV-C light sources, configured to reflect light emitted from the set of UV-C light sources, wherein the reflectors comprise polytetrafluoroethylene (PTFE) 2. A device according to claim 1, wherein the reflectors comprise a reflector body and a PTFE layer disposed on an outer surface of the reflector body.3. A device according to claim 2, wherein the outer surface of the reflector body comprises contours and the PTFE layer conforms to the contours.4. A device according to claim 3, wherein the reflector body is elongate and the contours comprise curved portions extending along a length of the reflector body.5. A device according to claim 3 or 4, wherein the outer surface of the reflector body comprises a flat portion between the curved portions.6. A device according to any of claims 2-5, wherein the reflectors comprise an adhesive layer between the PTFE layer and the outer surface of the reflector body.7. A device according to any preceding claim, wherein the PTFE layer has a thickness between 0.4-0.6mm.8. A device according to any preceding claim, wherein the PTFE layer is twice as thick as the adhesive layer.9. A device according to any preceding claim, wherein the PTFE is sintered polytetrafluoroethylene (S-PTFE).-15 - 10. A device according to any preceding claim, wherein the device is transportable, the device comprising a base including one or more wheels 11. A device according to any preceding claim, wherein the device is a tower having a substantially cylindrical shape defining a central longitudinal axis, wherein the set of reflectors is arranged concentrically inside of the set of UV-C light sources with respect to the central longitudinal axis.12. A reflector configured to be the reflector of any of claims 1-11.13. A method of manufacturing a reflector for use as the reflector of any of claims 1-11, the method comprising the steps of: forming a reflector body; applying a polytetrafluoroethylene (PTFE) layer to an outer surface of the reflector body.14. A method according to claim 13, wherein the step of forming a reflector body includes the step of: anodising the outer surface of the reflector body.A method according to claim 13 or 14, wherein the step of applying a polytetrafluoroethylene (PTFE) layer to an outer surface of the reflector body comprises: providing an adhesive tape comprising a PTFE layer; applying the adhesive tape onto the outer surface of the reflector body.16. A UV-C room disinfection tower comprising: an upstanding set of reflectors arranged inside an upstanding set of UV-C light sources, the reflectors arranged to reflect light emitted by the UV-C light sources; wherein the reflectors are coated in polytetrafluoroethylene (PTFE).