Sealing apparatus and method for sealing packaging

Abstract

A packaging includes a base foil and a cover foil, the base foil and/or the cover foil being formed from a water-soluble foil web. The apparatus includes a liquid supply for a water-containing liquid, at least one moistening unit, and a pressing device. The moistening unit is formed as a spraying device for contactlessly spraying the liquid onto the foil web and is positioned at a distance (a) from the foil web. The spraying device includes an electromechanical spraying system with a row of outlet nozzles for spraying the liquid onto the foil web. The water-soluble foil web is supplied to the sealing apparatus. A water-containing liquid is sprayed onto the foil web via the spraying device. The cover foil is led onto the base foil and is pressed and sealed together therewith, in the state in which they are wetted with the liquid, via a pressing device.

What is claimed is: 
     
         1 . A sealing apparatus for sealing packaging, wherein the packaging includes a base foil and a cover foil, at least one of said base foil and said cover foil being made of a water-soluble foil web, the sealing apparatus comprising:
 a liquid supply for a water-containing liquid;   a moistening unit configured to moisten the water-soluble foil web with the water-containing liquid;   a pressing device configured to press together and seal the cover foil and the base foil with the foil web being moistened;   said moistening unit being formed as a spraying device configured to spray the water-containing liquid onto the water-soluble foil web in a contact-free manner;   said spraying device being configured to be positioned at a distance a to the water-soluble foil web; and,   said spraying device being an electromechanical spray system having a row of outlet nozzles configured to spray the water-containing liquid onto the water-soluble foil web.   
     
     
         2 . The sealing apparatus of  claim 1 , wherein said electromechanical spray system includes a row of solenoid valves associated with said outlet nozzles. 
     
     
         3 . The sealing apparatus of  claim 1 , wherein said electromechanical spray system is movably mounted and controllable such that during operation said electromechanical spray system is configured to be directed toward said cover foil or a seam line between said cover foil and said base foil. 
     
     
         4 . The sealing apparatus of  claim 1  further comprising a doctor blade having a doctor blade edge configured to remove excess liquid from the water-soluble foil web. 
     
     
         5 . The sealing apparatus of  claim 4 , wherein said doctor blade edge and the water-soluble foil web are configured to define a mutual gap having a defined gap width B. 
     
     
         6 . The sealing apparatus of  claim 4 , wherein said doctor blade includes a suctioning device configured to suction off excess liquid removed by said doctor blade edge. 
     
     
         7 . The sealing apparatus of  claim 1  further comprising:
 a housing; 
 said spraying device being enclosed by said housing; and, 
 said housing defining a spray window for directed application of the liquid onto the water-soluble foil web. 
 
     
     
         8 . A method for sealing packaging via a sealing apparatus wherein the packaging includes a base foil and a cover foil, at least one of the base foil and the cover foil being made of a water-soluble foil web, the sealing apparatus including a liquid supply for a water-containing liquid, a moistening unit configured to moisten the water-soluble foil web with the water-containing liquid, a pressing device configured to press together and seal the cover foil and the base foil with the foil web being moistened, the moistening unit being formed as a spraying device configured to spray the water-containing liquid onto the water-soluble foil web in a contact-free manner, and, the spraying device being an electromechanical spray system having a row of outlet nozzles configured to spray the water-containing liquid onto the water-soluble foil web, the method comprising the steps of:
 feeding the water-soluble foil web to the sealing apparatus;   positioning the spraying device at a distance a to the water-soluble foil web;   spraying the water-containing liquid onto the water-soluble foil web via the spraying device;   guiding the cover foil onto the base foil; and,   pressing and sealing the cover foil to the base foil via the pressing device with the foil web in a wetted state.