Method of encapsulation

Abstract

A method of encapsulation is characterized by supplying to an encapsulation unit ( 22 ) two films ( 14, 16 ) of like material capable of deforming elastically at least when partially solvated, and applying solvent to at least one of the films prior to encapsulation to cause partial solvation of the material surface, such that the partially solvated surface can adhere to and seal with the film material. In the encapsulation unit, the substance to be encapsulated e.g. a cosmetic oil or vitamin preparation is supplied between the films, the films are formed, typically by a molding process, into suitably shaped capsule portions which can adhere to each other as a result of the adhesive action of the partially solvated surface(s), and which seal together encapsulating the supplied substance, forming a capsule. The invention enables encapsulation using materials other than gelatin, such as polyvinyl alcohol. Also disclosed is encapsulation apparatus and the resulting capsules.

1 . A method of encapsulation, characterised by supplying to an encapsulation unit two films of like material capable of deforming elastically at least when partially solvated, and applying solvent to at least on of the films prior to encapsulation to cause partial salvation of the material surface, such that the partially solvated surface can adhere to and seal with the film material.  
     
     
         2 . A method of encapsulation, comprising supplying two films of like material capable of deforming elastically at least when partially solvated; applying solvent to at least one of the films to cause partial solvation of the material surface; supplying substance to be encapsulated between the films; forming the films into suitably shaped capsule portions which can adhere to each other as a result of the adhesive action of the partially solvated surface(s); and sealing the capsule portions together, encapsulating the supplied substance, to form a capsule.  
     
     
         3 . A method according to  claim 2 , wherein a vacuum is applied during capsule portion formation to assist deformation of the film material.  
     
     
         4 . A method according to  claim 1 ,  2  or  3 , wherein the film material is selected from polyvinyl alcohol, alginate, hydroxypropyl methyl cellulose, polyethylene oxide, polycaprolactone and gelatinized starch based materials.  
     
     
         5 . A method according to  claim 4 , wherein the film material is polyvinyl alcohol and the solvent is water.  
     
     
         6 . A method according to any one of the preceding claims, wherein the film material becomes more flexible on partial solvation.  
     
     
         7 . A method according to any one of the preceding claims, wherein the solvent is applied just prior to encapsulation.  
     
     
         8 . A method according to any one of the preceding claims, wherein the solvent applied by means of a gravure or flexo printing process.  
     
     
         9 . Encapsulation apparatus comprising means for supplying two films of material to an encapsulation unit; an encapsulation unit; and means for supplying a solvent for the film material to at least one of the films upstream of the encapsulation unit.  
     
     
         10 . Apparatus according to  claim 9 , wherein the encapsulation unit comprises a pair of counter-rotating moulding drums, and an associated arrangement for coordinated supply of substance to be encapsulated.  
     
     
         11 . Apparatus according to  claim 10 , including means for applying a vacuum inside the moulding drums.