Method and apparatus for coating a multiple number of layers onto a substrate

Claim 1

A METHOD OF SIMULTANEOUSLY COATING A PLURALITY OF DISTRICT SUPERPOSED LAYERS OF LIQUID COATING COMPOSITIONS ONTO A SUBSTRATE FROM AN EXTRUSION-SLIDE COATING HOPPER HAVING BOTH AN EXTRUDER SLOT AND A DOWNWARDLY INCLINED SLIDE SURFACE, WHICH METHOD COMPRISES THE STEPS OF: EXTRUDING A FIRST LIQUID COATING COMPOSITION FROM AN EXTRUDER SLOT ACROSS A GENERALLY HORIZONTAL GAP TO THE SUBSTRATE; SIMULTANEOUSLY FEEDING A SECOND LIQUID COATING COMPOSITION IN THE FORM OF A LAYER ONTO THE UPPER PORTION OF THE INCLINED SLIDE SURFACE SO THAT THE SECOND LIQUID LAYER FLOWS AS A LAYER BY GRAVITY DOWNWARDLY ON THE INCLINED SLIDE SURFACE TOWARD THE SUBSTRATE; ALTERING THE DIRECTION OF FLOW OF THE SECOND LAYER AT A LOWER LIP PORTION OF THE SLIDE SURFACE TO A DIRECTION CLOSER TO HORIZONTAL THAN THE DIRECTION OF THE UPPER PORTION OF THE SLIDE SURFACE SO THAT THE SECOND LIQUID LAYER FLOWS IN A MORE HORIZONTAL DIRECTION AS IT APPROACHES THE SUBSTRATE; FLOWING THE SECOND LIQUID LAYER FROM THE LOWER PORTION OF THE SLIDE SURFACE ON TO THE EXTRUDED FIRST LAYER BRIDGING THE GAP; AND MOVING THE SUBSTRATE IN A GENERALLY UPWARD DIRECTION ACROSS AND IN CONTACT WITH THE BRIDGE OF COATING COMPOSITIONS SO THAT THE SURFACE OF THE SUBSTRATE PICKS UP AND IS COATED BY THE PLURALITY OF LIQUID COMPOSITION LAYERS.

Claim 2

A METHOD OF SIMULTANEOUSLY COATING A PLURALITY OF DISTRICT SUPERPOSED LAYERS OF LIQUID COATING COMPOSITIONS ONTO A SUBSTRATE FROM AN EXTRUSION-SLIDE COATING HOPPER HAVING BOTH AN EXTRUDER SLOT AND A DOWNWARDLY INCLINED SLIDE SURFACE, WHICH METHOD COMPRISES THE STEPS OF: EXTRUDING A FIRST LIQUID COATING COMPOSITION FROM AN EXTRUDER SLOT ACROSS A GENERALLY HORIZONTAL GAP TO THE SUBSTRATE; SIMULTANEOUSLY FEEDING A SECOND LIQUID COATING COMPOSITION IN THE FORM OF A LAYER ONTO THE UPPER PORTION OF THE INCLINED SLIDE SURFACE SO THAT THE SECOND LIQUID LAYER FLOWS AS A LAYER BY GRAVITY DOWNWARDLY ON THE INCLINED SLIDE SURFACE TOWARD THE SUBSTRATE; ALTERING THE DIRECTION OF FLOW OF THE SECOND LAYER AT A LOWER LIP PORTION OF THE SLIDE SURFACE TO A DIRECTION CLOSER TO HORIZONTAL THAN THE DIRECTION OF THE UPPER PORTION OF THE SLIDE SURFACE SO THAT THE SECOND LIQUID LAYER FLOWS IN A MORE HORIZONTAL DIRECTION AS IT APPROACHES THE SUBSTRATE; FLOWING THE SECOND LIQUID LAYER FROM THE LOWER PORTION OF THE SLIDE SURFACE ON TO THE EXTRUDED FIRST LAYER BRIDGING THE GAP; AND MOVING THE SUBSTRATE IN A GENERALLY UPWARD DIRECTION ACROSS AND IN CONTACT WITH THE BRIDGE OF COATING COMPOSITIONS SO THAT THE SURFACE OF THE SUBSTRATE PICKS UP AND IS COATED BY THE PLURALITY OF LIQUID COMPOSITION LAYERS.

Claim 7

A method of simultaneously coating a plurality of distinct superposed layers of liquid coating compositions onto a web substrate from an extrusion-slide coating hopper having both an extruder slot and a downwardly inclined slide surface, which method comprises the steps of: extruding a first liquid coating composition from an extruder slot across a generally horizontal gap to the substrate; simultaneously feeding a plurality of the other liquid coating compositions, each in the form of a layer and in superposed relation to the others of said other composition layers, onto the upper portion of the slide surface which is inclined downwardly at a first predetermined angle with respect to horizontal such that said other liquid composition layers flow down the surface by gravity; altering the direction of flow of said other layers at a lower portion of the slide surface to a second predetermined angle of inclination less than said first angle of inclination so that said other liquid composition layers flow more horizontally; flowing said other liquid layers from the lower portion of the slide surface onto the extruded layer bridging the generally horizontal gap to the substrate to be coated; and moving the substrate in a generally upward direction across and in contact with the liquid composition layers so that the surface of the substrate engages the extruded layer and simultaneously picks up all of said compositions in distinct superposed layers.

Claim 8

A method of simultaneously coating a plurality of distinct superposed layers of liquid coating compositions onto a web substrate from an extrusion-slide coating hopper having both an extruder slot and a downwardly inclined slide surface, which method comprises the steps of: extruding a first liquid coating composition from an extruder slot across a generally horizontal gap to the substrate; simultaneously feeding a plurality of the other liquid coating compositions, each in the form of a layer and in superposed relation to the others of said other composition layers, onto the upper portion of the slide surface which is inclined downwardly at a first predetermined angle with respect to horizontal such that said other liquid composition layers flow down the surface by gravity; altering the direction of flow of said other layers at a lower portion of the slide surface to a second predetermined angle of inclination less than said first angle of inclination so that said other liquid composition layers flow more horizontally; flowing said other liquid layers from the lower portion of the slide surface onto the extruded layer bridging the generally horizontal gap to the substrate to be coated; and moving the substrate in a generally upward direction across and in contact with the liquid composition layers so that the surface of the substrate engages the extruded layer and simultaneously picks up all of said compositions in distinct superposed layers.