Process of sealing polyvinylalcohol films

A process for sealing a first water-soluble polyvinylalcohol film to a second water-soluble polyvinylalcohol film, wherein the first water-soluble polyvinylalcohol film has a first side and a second side, and wherein the second water-soluble polyvinylalcohol film has a first side and a second side, wherein the process comprises the steps of:

• a. applying a liquid solvent sealing composition onto at least a part of the first side of the first water-soluble polyvinylalcohol film;
• b. contacting at least a part of the first side of the second water-soluble polyvinylalcohol film with at least a part of the first side of the first water-soluble polyvinylalcohol film which was sprayed with the liquid solvent sealing composition;
• c. applying the liquid sealing solvent composition onto at least a part of the second side of the first water-soluble polyvinylalcohol film or at least a part of the second side of the second water-soluble polyvinylalcohol film, wherein, the liquid sealing solvent composition is applied as a spray from a nozzle;
• d. contacting at least a part of a first side of a third water-soluble polyvinylalcohol film with the part of the second side of the first water-soluble polyvinylalcohol film or second side of the second water-soluble polyvinylalcohol film, which was sprayed with the liquid sealing solvent composition;
• wherein the liquid solvent sealing composition is applied as a spray from a nozzle,
• wherein the nozzle comprises an outlet orifice and wherein the liquid solvent sealing composition is ejected from the outlet orifice;
• wherein the shortest distance from the outlet orifice to the first side of the first water-soluble polyvinylalcohol film is between about 40 mm and about 160 mm;
• wherein the spray has an average droplet size d50 of between about 50 microns and about 200 microns before it contacts the first side of the first water-soluble polyvinylalcohol film,
• wherein the average droplet size d50 is measured via optical imaging of spray droplets after being sprayed from the nozzle, wherein the spray droplets being measured are at a distance of about 100 mm perpendicular to the outlet orifice, and wherein the nozzle is orientated such that the spray exits the outlet orifice vertically and the image is captured perpendicular to the direction of movement of the droplets once they exit the outlet orifice using the Droplet Size Test Method described herein.