Web cleaner

• US 20060086272A1
• Filed: 10/21/2005
• Published: 04/27/2006
• Est. Priority Date: 10/22/2004
• Status: Abandoned Application

• Current Assignee: PDM Ltd. (Compagnie de Saint-Gobain SA)
• Original Assignee: PDM Ltd. (Compagnie de Saint-Gobain SA)
• Inventors: Bennet, Leslie
• Application Number:
  US11/256,434
• Publication Number:
  US 20060086272A1
• Time in Patent Office: Days
• US Class Current: 101/425
• CPC Class Codes: B08B 1/20 Cleaning of moving articles, e.g. of moving webs or of objects on a conveyor
• CPC Class Codes: B08B 15/04 from a small area, e.g. a tool removing chips B23Q11/0042
• CPC Class Codes: B08B 5/026 Cleaning moving webs
• CPC Class Codes: B08B 5/046 Cleaning moving webs
• CPC Class Codes: B41F 23/002 cleaning devices for sheets or webs

Abstract

The invention is relates a web cleaning apparatus including: a pair of operatively rotating cleaning rollers operatively disposed on opposite sides of the web; a housing surrounding a major part of the surface of each roller; a vacuum chamber substantially co-extensive with each roller; a longitudinal slot extending parallel to each roller and substantially co-extensive therewith, the slot having an inlet proximate the roller surface and an outlet in communication with the vacuum chamber and operatively providing an air flow path from adjacent the roller into the vacuum chamber, wherein the air flow speed at each inlet is not less than the surface speed of the rollers, and a method of using such apparatus. Another apparatus of the invention includes a housing surrounding the roller and spaced therefrom with a gap of about 0.5 mm to about 5 mm. Further embodiments of the invention provide a shutter for controlling the air flow around the rollers in a cleaning step. Further embodiments of the invention provide a valve controlled bypass line whereby a given portion of a web cleaning apparatus can communicate with the atmosphere such that it is not under vacuum.

Claims

1. A web cleaning apparatus comprising:

a pair of operatively rotating cleaning rollers operatively disposed on opposite sides of the web;

a housing surrounding a major part of the surface of each roller;

a vacuum chamber substantially co-extensive with each roller; and

a longitudinal slot extending parallel to each roller and substantially co-extensive therewith, the slot having an inlet proximate the roller surface and an outlet in communication with the vacuum chamber and operatively providing an air flow path from adjacent the roller into the vacuum chamber,

wherein the air flow speed at each inlet is not less than the surface speed of the rollers.

2. The web cleaning apparatus as claimed in claim 1, wherein the air flow speed at each inlet is at least 1% greater than the surface speed of the rollers.

3. The web cleaning apparatus as claimed in claim 1, wherein the air flow speed at each inlet is at least 10% greater than the surface speed of the rollers.

4. The web cleaning apparatus as claimed in claim 1, wherein the air flow speed at each inlet is at least 50% greater than the surface speed of the rollers.

5. The web cleaning apparatus as claimed in claim 1, wherein the rollers are so spaced apart in use as to provide a clearance gap between each roller and the respective side of the web.

6. The web cleaning apparatus as claimed in claim 1, wherein the rollers are so spaced apart in use as to provide a gap of not more than 6 mm between each roller and the respective side of the web.

7. The web cleaning apparatus as claimed in claim 1, wherein the rollers are so spaced apart in use as to provide a gap of not more than 3 mm between each roller and the respective side of the web.

8. The web cleaning apparatus as claimed in claim 1, wherein the rollers are so spaced apart in use as to provide a gap of not more than 1 mm between each roller and the respective side of the web.

9. The web cleaning apparatus as claimed in claim 1, wherein the rollers rotate in a direction opposite to the direction of movement of the web.

10. The web cleaning apparatus as claimed in claim 9, wherein the inlet of the slot is arranged on the upstream side of the roller with respect to the direction of movement of the web.

11. The web cleaning apparatus as claimed in claim 9, wherein the differential between the surface speed of each roller and the speed of the web is from about 5 ms⁻

1 to about 30 ms<sup>−

1</sup>.

12. The web cleaning apparatus as claimed in claim 9, wherein the differential between the surface speed of each roller and the speed of the web is from about 6 ms⁻

1 to about 12 ms<sup>−

1</sup>.

13. The web cleaning apparatus as claimed in claim 9, wherein the differential between the surface speed of each roller and the speed of the web is about 10 ms⁻

1.

14. A method of cleaning a moving web comprising:

providing an apparatus comprising

a pair of rotating cleaning rollers disposed on opposite sides of the web;

a housing surrounding a major part of the surface of each roller;

a vacuum chamber substantially co-extensive with each roller and connected to a vacuum source;

a longitudinal slot extending parallel to each roller and substantially co-extensive therewith, the slot having an inlet proximate the roller surface and an outlet in communication with the vacuum chamber and operatively providing an air flow path from adjacent the roller into the vacuum chamber, and

operating the rollers and the vacuum source such that the air flow speed at each inlet is not less than the surface speed of the rollers.

15. The method of claim 14, wherein the air flow speed at each inlet is at least 1% greater than the surface speed of the rollers.

16. The method of claim 14, wherein the air flow speed at each inlet is at least 10% greater than the surface speed of the rollers.

17. The method of claim 14, wherein the air flow speed at each inlet is at least 50% greater than the surface speed of the rollers.

18. The method of claim 14, wherein the rollers rotate in a direction opposite to the direction of movement of the web.

19. The method of claim 18, wherein the inlet of the slot is arranged on the upstream side of the roller with respect to the direction of movement of the web.

20. A web cleaning apparatus comprising:

a pair of operatively rotating cleaning rollers operatively disposed on opposite sides of the web;

a vacuum chamber substantially co-extensive with each roller;

a longitudinal slot extending parallel to each roller and substantially co-extensive therewith, the slot having an inlet proximate the roller surface and an outlet in communication with the vacuum chamber and operatively providing an air flow path from adjacent the roller into the vacuum chamber,

a housing surrounding a major part of the surface of each roller, and

wherein the housing has a part-cylindrical internal surface opposed to the external surface of the roller and spaced therefrom with a gap of about 0.5 mm to about 5 mm.