COATING LINE CLEANING APPARATUS

Abstract

The invention relates to a coating line (1) cleaning apparatus (20) and a method for cleaning at least a selected part of a coating line. The coating line cleaning apparatus comprising a conveyed entity having first and second mutually opposed major faces and at least one flexible cleaning element (12) having first and second mutually opposed major faces, said cleaning element being characterised in that each one of said first (15) and second (11) major faces is tacky, the first of said tacky faces of said cleaning element being releasably adhered to one of the major faces (8) of the conveyed entity (4), and the second tacky major face of said cleaning element being temporarily contactable with the selected part (14) of the coating line to bring said second tacky major face (11) of the cleaning element into temporary contact with said selected part of a coating line to cause any contaminants present on said selected part (14) of a coating line (1) to adhere to said second tacky major face (11) of said cleaning element thereby causing any contaminants to be removed from said selected part of a coating line (1).

Claims

1. A coating line cleaning apparatus for cleaning at least a selected part of a coating line, comprising a conveyed entity having first and second mutually opposed major faces and at least one flexible cleaning element having first and second mutually opposed major faces, said cleaning element being characterised in that each one of said first and second major faces is tacky, the first of said tacky faces of said cleaning element being releasably adhered to one of the major faces of the conveyed entity, and the second tacky major face of said cleaning element being temporarily contactable with the selected part of the coating line to bring said second tacky major face of the cleaning element into temporary contact with said selected part of a coating line to cause any contaminants present on said selected part of a coating line to adhere to said second tacky major face of said cleaning element thereby causing any contaminants to be removed from said selected part of a coating line.

2. A coating line cleaning apparatus according to claim 1, wherein the cleaning element is releasably adhered to the first or the second major face of the conveyed entity.

3. A coating line cleaning apparatus according to claim 2, wherein the cleaning element is releasably adhered to the conveyed entity by adhesion forces.

4. A coating line cleaning apparatus according to claim 3, wherein the surface adhesion forces between the first tacky surface of the cleaning element and the major face of the conveyed entity are greater than the surface adhesion forces between the second tacky surface of the cleaning element and the selected part of the coating line.

5. A coating line cleaning apparatus according to claim 3, wherein the surface adhesion forces between the first tacky surface of the cleaning element and the major face of the conveyed entity are greater than the surface adhesion forces between the second tacky surface of the cleaning element and the selected part of the coating line to be cleaned by the cleaning apparatus.

6. A coating line cleaning apparatus according to claim 1, wherein the surface adhesion properties of the first and second tacky surfaces of the cleaning element are provided by one or more of mechanical adhesion forces, chemical adhesion forces, shore hardness and/or electrical adhesion forces.

7. A coating line cleaning apparatus according to claim 1, wherein the cleaning element is made from or comprises elastomer material.

8. A coating line cleaning apparatus according to claim 1, wherein the cleaning element is made from or comprises any one of: polyurethane, silicon-free polymer, hydrogel polymer, isoprene, polyvinylchloride or a silicon-based polymer.

9. A coating line cleaning apparatus according to claim 1, wherein the conveyed entity comprises a flexible substrate material.

10. A coating line cleaning apparatus according to claim 9, wherein the substrate material is a web of flexible material.

11. A coating line cleaning apparatus according to claim 1, wherein the cleaning element is releasably adhered to a portion of the conveyed entity.

12. A coating line cleaning apparatus according to claim 11, wherein the cleaning element is releasably adhered to a major face of the conveyed entity proximate a leading edge of the conveyed entity.

13. A coating line cleaning apparatus according to claim 12, wherein a cleaning element is releasably adhered to a major face of the conveyed entity remote from the leading edge of the conveyed entity.

14. A coating line cleaning apparatus according to claim 1, wherein the cleaning element is releasably adhered to a portion of the first major face of the conveyed entity.

15. A coating line cleaning apparatus according to claim 1, wherein the cleaning element is releasably adhered to a portion of the second major face of the conveyed entity.

16. A coating line cleaning apparatus according to claim 1, wherein a cleaning element is releasably adhered to a portion of the first major face of the conveyed entity and a further cleaning element is releasably adhered to a portion of the second major face of the conveyed entity.

17. A coating line cleaning apparatus according to claim 1, wherein the cleaning element is a sheeted material.

18. A coating line cleaning apparatus according to claim 1, wherein the, or each, cleaning element is releasably adhered to and is supported by the conveyed entity.

19. A coating line cleaning apparatus according to claim 1, wherein the selected part of the coating line comprises a supporting surface of at least one supporting element.

20. A coating line cleaning apparatus according to claim 19, wherein the at least one supporting element is a rotatable roller.

21. A coating line cleaning apparatus for cleaning at least a selected part of a coating line, said coating line comprising at least one rotatable supporting element, said at least one rotatable supporting element comprising at least one supporting surface contactable with a conveyed entity in use of said coating line to support said conveyed entity as it is conveyed in a conveying direction through said coating line, said at least one supporting surface constituting said selected part of said coating line, said cleaning apparatus comprising a conveyed entity having first and second mutually opposed major faces and at least one flexible cleaning element having first and second mutually opposed major faces, said cleaning element being characterised in that at each one of said first and second major faces is tacky, the first of said tacky faces of the cleaning element being releasably adhered to one of the major faces of the conveyed entity, and the second of said tacky major faces of the cleaning element being temporarily contactable with said at least one supporting element to bring said second tacky major face of said at least one flexible cleaning element into temporary contact with said at least one supporting surface of said at least one rotatable supporting element during use of said cleaning apparatus to cause any contaminants present on said at least one supporting surface to adhere to said second tacky major face of said at least one flexible cleaning element and to cause any so-adhered contaminants to be removed with said at least one flexible cleaning element at the cessation of said temporary contact of said at least one cleaning element with said at least one supporting element whereby to clean at least said selected part of said coating line.

22. (canceled)

23. A coating line cleaning apparatus according to claim 21, wherein the conveyed entity and the cleaning element are retained in intimate contact with one another as the cleaning apparatus is conveyed through the coating line.

24. A cleaning method for cleaning at least a selected part of a coating line, said coating line comprising at least one supporting element, said at least one supporting element comprising at least one supporting surface contactable with a conveyed entity in use of said coating line to support said conveyed entity as it is conveyed in a conveying direction of said coating line, said at least one supporting surface constituting said selected part of said coating line, said method being characterised by the steps of providing a cleaning apparatus, releasably adhering a first major surface of the at least one cleaning element to a major face of the conveyed entity, temporarily contacting the second tacky major face of the at least one cleaning element of said cleaning apparatus with said at least one supporting surface of said coating line in a manner to cause said second major face of the cleaning element and said conveyed entity to progress in said conveying direction along substantially the full length of said at least one supporting surface and to cause any contaminants present on said at least one supporting surface to adhere to said second major face of the at least one cleaning element, and finally withdrawing said at least one cleaning element from said temporary contact with said at least one supporting element to cause any so-adhered contaminants to be removed with said at least one cleaning element whereby to clean at least said selected part of said coating system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Embodiments of the present invention will now be described by way of example, with reference to the accompanying drawings wherein:

[0050] FIG. 1 is a side view of a first embodiment of a coating line cleaning apparatus in accordance with the present invention, the first embodiment of the cleaning apparatus being shown located within a multi-roller coating line;

[0051] FIG. 2 is a perspective view of a cleaning apparatus in accordance with an embodiment of the present invention, a single cleaning element being shown located on the upper major face of a web substrate conveyed entity and having a corner of the cleaning element lifted away from the major face of the web substrate;

[0052] FIG. 3 is a perspective view of a cleaning apparatus in accordance with an alternative embodiment of the present invention, with two cleaning elements being shown located on mutually opposing major faces of a web substrate conveyed entity; and

[0053] FIG. 4 is a perspective view of a cleaning apparatus in accordance with a further alternative embodiment of the present invention, with two cleaning elements being shown located on mutually opposing major faces of a web substrate conveyed entity between the leading and trailing edges of the conveyed entity.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

[0054] Referring first to FIG. 1, there is shown a coating line 1 having multiple processing stations 1a, 1b, 1c, 1d, 1e. A web substrate 3 is pulled through the coating line 1 from an unwind roll 5 to a rewind roll 7 over a series of offset supporting rollers 14 of varying diameters and surface materials. The supporting surfaces of the rollers 14 support the web substrate 3 as it passes through the coating line 1. The roller surfaces of each roller 14 in the coating line will contact either the front side of the web substrate 3 or the back side of the web substrate 3. The web substrate 3 travels through multiple planes as it is conveyed through the coating line 1 from the unwind roll 5 to the rewind roll 7. The web substrate 3 is pulled through the coating line 1 by a pull roller (not shown) located proximate the rewind roller 7. By pulling the web substrate through the coating line 1, the web 3 is placed under tension as it passes over the surface of each of the rollers 14.

[0055] Each station within the coating line 1 has a function within the coating line. In the depicted embodiment, station 1a is a surface cleaning station comprising contact cleaning apparatus having cleaning rollers 14a. Station 1b is a web alignment station comprising alignment rollers 14c and station 1c comprises rollers 14d, typically having a ceramic surface. Station 1d is a substrate web 3 coating station comprising rollers 14e and 1e is an oven in which transport rollers 14f. Various of the rollers 14 may have a dimpled PTFE surface and act as tension rollers within the coating line. Such tension rollers apply friction forces to the substrate web 3 and, due to the slip of web material over the rollers, contaminants build up on the surface of the rollers 14. During operation of the coating line 1, contaminants build up on the surfaces of the rollers 14, 14a, 14c, 14d, 14e, 14f. Such contamination will be transferred to the surfaces of the substrate web 3 unless removed by cleaning.

[0056] In-line cleaning of the coating line is made possible by the cleaning apparatus of the present invention.

[0057] As depicted in FIG. 1, a cleaning apparatus 20 for use in cleaning the rollers 14 of a coating line 1. The cleaning apparatus 20 comprises a conveyed entity 4 in the form of the flexible web 3 of filmic substrate material in the proximity of a cleaning element 6 in the form of a rectangular sheet of polyurethane 12 (see FIG. 2) is releasably adhered by surface adhesion forces to the front side 8 of the conveyed entity 4 and is arranged to be in contact with the rollers 14 of the coating line 1. The rectangular sheet 12 is flexible and is of greater length than the circumference of at least one roller 14 such that as the rectangular sheet 12 passes over the surface of each roller 14, the entire surface of each roller 14 comes into contact with the tacky polyurethane surface of the rectangular sheet 12.

[0058] The cleaning apparatus 1 of FIG. 1 is shown in FIG. 2 without the coating line. In this embodiment, the cleaning apparatus 20 comprises a single flexible rectangular sheet of polymer 12, the first tacky major face 15 of which is releasably adhered by surface adhesion forces, such as van der Waals forces, to the first major surface 8 of a flexible web 4 of material to be coated so forming the cleaning apparatus 20. The flexible nature of the rectangular sheet 12 ensures a greater area of contact of the tacky second surface 11 of sheet 12 over the surface of the rollers in a coating line. The surface adhesion forces between major face 15 of sheet 12 and surface 4 of the web and retaining the sheet 12 in contact with the surface 4 of the web material are greater than the surface adhesion forces between the second major face 11 of sheet of polymer 12 and the surface of each roller 14 of the coating line (see FIG. 1). This ensures the cleaning apparatus remains intact through the entire coating line. The surface adhesion forces between the sheet 10 and the contaminants on the surface of each roller 14 of the coating line is greater than the adhesion forces between the contaminants and the surface of the roller 14. In this way, contaminants are removed from the surface of each roller 14 as the sheet 12 passes in temporary contact with the surface of each roller 14. In FIG. 2, a corner of sheet 12 is shown lifted away from the conveyed entity surface of the web 4 so show that the sheet 12 is releasably adhered to the conveyed entity 4.

[0059] The alternative embodiment of the cleaning apparatus 200 shown in FIG. 3 comprises two cleaning elements 30a and 30b each in the form of a rectangular sheet of isoprene polymer. One cleaning element 30a is releasably adhered by surface adhesion forces to the front side 8 of a substrate web 3 in the region of conveyed entity substrate web 4 and the other cleaning element 30b is releasably adhered by surface adhesion forces to the back side 17 of a substrate web 3 in the region of conveyed entity substrate web 4 so forming cleaning apparatus 200. The cleaning apparatus 200 so formed is capable of cleaning the surface of any roller 14 in the coating line contacting the front 8 or the back side 17 of the substrate web 3.

[0060] FIG. 4 shows the cleaning apparatus 200 of FIG. 3 however the two cleaning elements 30a and 30b are located between the leading edge 31 and the trailing edge 33 of the substrate web 3. Such a cleaning apparatus 200 is operable to clean a coating line during operation of the coating line 1 and without having to shut down the coating line in order for the coating line to be cleaned.

[0061] In operation of the coating line of FIG. 1, the cleaning apparatus 20, 200 comprising a cleaning sheet 6, 30a, 30b of flexible polyurethane polymer releasably adhered by surface adhesion forces to the web substrate conveyed entity 4 is pulled through the coating line by a pull roller (not shown) located at the end of the coating line 1 proximate the rewind roll 7. The substrate web 3, including the cleaning apparatus 20, 200, is placed under tension in the coating line 1 and is conveyed into contact with the surfaces of each of the rollers 14. The surfaces of each of the rollers is cleaned by contact with the tacky surface of major face 11 of the cleaning sheet 20, 200. The rollers 14 of coating line 1 are then driven by the movement of the conveyed substrate web 3 over the surfaces of the rollers 14 in the normal conveying direction “C” in FIGS. 1 and 4. As the rectangular sheet 6 moves along the rollers 14 any dirt, dust or other contaminants on the rollers 14 is picked up by the tacky surface 11 of the rectangular sheet 6. This is due to the tackiness of the polymer 12 which picks up all loose materials on the surfaces of the rollers 14.

[0062] Once the rollers 14 have been cleaned the flexible rectangular sheet 6 may be discarded or alternatively removed and cleaned for subsequent re-use.

[0063] The present invention provides a coating line cleaning apparatus and a coating line cleaning method for removing contaminants from rollers or other supporting elements of a coating line in a simple and efficient manner. The cleaning apparatus and method greatly reduce the risk of contamination of the conveyed entity being conveyed through the coating line and obviate the need for manual cleaning of the rollers 14 (for example, by wiping the rollers with a cloth). The cleaning apparatus and cleaning method facilitate the cleaning of a coating line whilst the line is in operation as the cleaning element may simply be releasably adhered to the substrate material (conveyed entity) being pulled through the coating line. Once the cleaning apparatus comprising the cleaning element releasably adhered to the conveyed entity has passed through the coating line towards the rewind roll of the coating line, the cleaning element may be removed from the conveyed entity. The cleaning element may be cleaned for further use or otherwise discarded.

[0064] The cleaning element of the cleaning apparatus of the present invention may be constructed as a flexible sheet of polymer material. The tacky properties of the first and second mutually opposed major surfaces of the cleaning sheet being due to the surface adhesion forces of the polymer material. The sheets of cleaning element may be formed entirely from the polymer material and the surface adhesion forces providing the tacky surfaces may be predetermined to provide the required cleaning properties.

[0065] The invention is particularly applicable to the cleaning of rollers in a coating line supporting flexible substrate materials to be coated in the line and whose finished quality is paramount. While certain modifications and variations have been described above, the invention is not restricted thereto, and other modifications and variations can be adopted without departing from the scope of the invention as defined in the appended claims.