Web lifter/stabilizer and method
View Patent ↗Web lifter and/or stabilizer and method of lifting and/or stabilizing a travelling web and for coating a web. The device creates a web hold down force via a negative pressure slot at its exit side, which draws the web down against the surface on the entry side. The device can be actuated to move the web relative to a slot die coater off the die lips and stop the application of slurry to the web, thereby creating uncoated regions on the web surface. The device can then be actuated to move the web back into contact with the coater to start the application of slurry to the web, thereby creating coated regions on the web surface. Web lifting can be accomplished by rotating the device in first and second directions to lift the web off of the slot die coater and return the web back into contact with the coater.
1. A system for applying a coating to a material, travelling in a path, comprising:
a nozzle to apply said coating;
a supply valve in communication with said nozzle to allow the flow of coating to said nozzle;
a bypass valve to direct the flow of coating away from said nozzle;
a fluid displacement mechanism to draw coating away from said nozzle after said supply valve has been closed, wherein said fluid displacement mechanism comprises a chamber having a changeable volume; and
an actuator positioned such that movement of said actuator causes a change in said volume;
a web lifter moveable to deflect said material, said web lifter having a surface and a body moveable between a first position in which said material travels in an undeflected state and a second position in which said material is deflected by said body so as to travel in a deflected state, said web lifter body having a first portion defining a leading edge of said body, and a second portion defining a trailing edge of said body, said first portion being spaced from said second portion so as to define an air entry slot between them for the entry of air upon the application of negative pressure to said body, and a vacuum source in fluid communication with said body for receiving said air that enters said slot, said applied negative pressure positioning said web into contact with said surface; and
a controller in communication with said supply valve, said bypass valve, said actuator, said nozzle and said web lifter so as to control the application of said coating to said material.
2. The system of claim 1 , wherein said controller comprises memory storage to store reference position data for said travelling material.
3. The system of claim 2 , wherein said reference position data comprises positions of said travelling material where said supply valve is to open and close.
4. The system of claim 2 , wherein said reference position data comprises positions of said travelling material where said bypass valve is to open and close.
5. The system of claim 2 , wherein said reference position data comprises positions of said travelling material where said web lifter is to be actuated to deflect said material.
6. The system of claim 1 , further comprising a sensor in communication with said controller for tracking the position of said material.
7. The system of claim 1 , wherein said web lifter is positioned upstream of said nozzle in the direction of travel of said material travelling in said path.
8. The system of claim 1 , wherein said material is a conductive substrate.
9. The system of claim 1 , further comprising a source of negative pressure in fluid communication with said body of said web lifter.
10. The system of claim 1 , wherein said controller is configured to rotate said body of said web lifter.
11. The system of claim 1 , wherein said controller controls the opening and closing of said bypass valve and the speed at which said bypass valve is opened and closed.
12. The system of claim 1 , wherein said controller controls the opening and closing of said supply valve and the speed at which said supply valve is opened and closed.