Film coating apparatus and method

Claim 1

A PROCESS FOR APPLYING A COATING COMPOSITION CONSISTING OF AN AQUEOUS DISPERSION OF A POLYMER OR COPOLYMER RESIN TO BOTH SIDES OF A CONTINUOUS WEB OF FILM, WHICH COMPRISES CAUSING THE WEB TO PASS THROUGH THE NIP OF A PAIR OF HORIZONTALLY DISPOSED APPLICATOR ROLLS, GUIDING THE WEB SO THAT IT RETURNS TO PASS AGAIN THROUGH THE SAID NIP IN THE SAME DIRECTION, BUT WITH THAT FACE OF THE FILM WHICH WAS REMOTE FROM ONE ROLL DURING SAID FIRST PASS BEING IN CONTACT WITH THE OTHER ROLL DURING SAID SECOND PASS, APPLYING A COATING COMPOSITION SIMULTANEOUSLY TO THE JUXTAPOSED FACES OF THE WEB AS IT PASSES THROUGH THE SAID NIP, AND SUBJECTING THE WEB TO A CONTINUOUS DRYING OPERATION BETWEEN ITS FIRST AND SECOND PASS THROUGH THE SAID NIP AND AFTER IT HAS PASSED THROUGH THE SAID NIP A SECOND TIME, THE JUXTAPOSED AREAS OF THE WEB PASSING THROUGH THE NIP BEING MAINTAINED IN CONTACT FOR A SUBSTANTIAL DISTANCE BEYOND THE EXIT SIDE OF THE NIP PRIOR TO THE SEPARATION OF THE WEBS, SAID DISTANCE BEING NOT GREATER THAN THAT AT WHICH THE MENISCUS OF LIQUID WHICH OTHERWISE FORMS BETWEEN THE JUXTAPOSED AREAS OF THE WEB AT THE EXIT SIDE OF THE NIP COMPLETELY DISAPPEARS WHEREBY THE COATING MATERIAL IS SPLIT AT THE POINT OF SEPARATION AND FORMS A CONTINUOUS COATING ON BOTH OF SAID WEBS.