Patent ID: 8642129
Filing Date: 2014-02-04
Classification: B32B,C08J,Y10T

Abstract:
1. A method of making a water-soluble film comprising polyvinyl alcohol that is resistant to solubility prior to being immersed in water and is substantially water-soluble when immersed in water, said method comprising the steps of: (a) forming a water-soluble film comprising polyvinyl alcohol, the water-soluble film having a first surface and a second surface; (b) wetting at least a portion of either the first surface or the second surface of the water-soluble film with only water; (c) spraying a salt solution comprising a salt and water, the salt concentration from about 0.01 M to about 10 M to at least one of said surfaces of said water-soluble film; the salt is selected from the group consisting of: sodium sulfate, sodium citrate, sodium tripolyphosphate, potassium citrate, potassium tripolyphosphate and mixtures thereof; (d) allowing the at least one of said surfaces of said water-soluble film to dry; and (e) forming said water-soluble film into a water-soluble pouch.