Method and apparatus for coating webs with a plurality of liquid layers

Claim 3

The method of claim 1 wherein said liquids are directed to said pool along generally mutually convergent paths.

Claim 4

The method of claim 1 wherein said liquids are directed to said pool along generally mutually parallel paths.

Claim 5

The method of claim 1 including the step of establishing a pressure differential across the liquid composition in said gap wherein the lowermost layer is exposed to a lower pressure.

Claim 6

The method of claim 2 including the step of establishing a pressure differential across the liquid composition in said gap wherein the lowermost layer is exposed to a lower pressure.

Claim 7

The method of claim 3 including the step of establishing a pressure differential across the liquid composition in said gap wherein the lowermost layer is exposed to a lower pressure.

Claim 8

Apparatus for coating a moving web with a liquid composition comprising a plurality of liquid layers wherein layers within said composition are separate and distinct comprising in combination a. means forming a cavity adjacent a path along which the web is to be moved; b. means forming a plurality of spaced liquid flow paths having discharge slots exiting into said cavity to admit a plurality of liquids into said cavity and thereby form a pool comprising a plurality of separate and distinct continguous superposed liquid layers with reduced velocities and increased thicknesses relative to the velocities of the liquids in the slots and the thicknesses of the slots, said slots being formed in locations spaced progressively farther from said path of web movement and said liquid flow paths being aligned in directions that do not intersect the web so that each flow path is accessible by a cleaning probe inserted through the path slot with the moving web in place; and c. means for flowing the liquids in said pool directly across a gap between said pool and said moving web to form a bead thinning said layers and contacting and coating said web.

Claim 9

Apparatus for coating a moving web with a liquid composition comprising a plurality of liquid layers wherein layers within said composition are separate and distinct comprising in combination a. means forming a cavity adjacent a path along which the web is to be moved; b. means forming a plurality of spaced liquid flow paths having discharge slots exiting into said cavity to admit a plurality of liquids into said cavity and thereby form a pool comprising a plurality of separate and distinct continguous superposed liquid layers with reduced velocities and increased thicknesses relative to the velocities of the liquids in the slots and the thicknesses of the slots, said slots being formed in locations spaced progressively farther from said path of web movement and said liquid flow paths being aligned in directions that do not intersect the web so that each flow path is accessible by a cleaning probe inserted through the path slot with the moving web in place; and c. means for flowing the liquids in said pool directly across a gap between said pool and said moving web to form a bead thinning said layers and contacting and coating said web.

Claim 10

The apparatus of claim 7 in which said slots exit into said cavity along generally mutually convergent paths.

Claim 11

The apparatus of claim 7 in which said slots exit into said cavity along generally mutually parallel paths.

Claim 12

The apparatus of claim 7 including means for establishing a pressure differential across the liquid composition in said gap wherein the lowermost layer is exposed to a lower pressure.

Claim 13

The apparatus of claim 8 including means for establishing a pressure differential across the liquid composition in said gap wherein the lowermost layer is exposed to a lower pressure.

Claim 14

The apparatus of claim 9 including means for establishing a pressure differential across the liquid composition in said gap wherein the lowermost layer is exposed to a lower pressure.