Process and Mould for Thermoforming Containers

Abstract

A method of manufacturing water-soluble containers using a horizontal intermittent motion thermoforming machine comprises: a) locating a first water-soluble film over a mould, said mould containing a plurality of pocket forming cavities, defined by side walls and a base, in a 2-dimensional array, each cavity being surrounded by a planar surface of the mould on all sides; b) thermoforming the first film to produce a plurality of pockets; c) at least partially filling the pockets with a composition; and d) sealing the plurality of the at least partially filled pockets. The cavities are positioned in the array such that there are a plurality of continuous strips of uninterrupted planar surface of the mould from a leading to a trailing edge of the mould, for receiving support means fitted to the machine for supporting the film.

1 - 20 . (canceled) 
     
     
         21 . A mould for use in a thermoforming process for manufacturing water-soluble containers from water-soluble films, in which said mould contains a plurality of pocket forming cavities, defined by side walls and a base, in a 2-dimensional array, each cavity being surrounded by a planar surface of the mould on all sides in which the shortest dimension of the planar surface between two adjacent cavities is at least 3 mm and between an edge of the mould and the closest cavity is at least 1.5 mm, and in which the cavities are positioned in the array such that there are a plurality of continuous strips of uninterrupted planar surface of the mould from a leading to a trailing edge of the mould. 
     
     
         22 . A mould as claimed in  claim 21  in which the depth of the cavities lies in the range of 10 to 80% of the shortest dimension of the cavity mouth. 
     
     
         23 . A mould as claimed in  claim 21  in which the depth of the cavities lies in the range of 40 to 60% of 10 the shortest dimension of the cavity mouth. 
     
     
         24 . A mould as claimed in  claim 21  in which the cavity bases are planar. 
     
     
         25 . A mould as claimed in  claim 21  in which the cavity bases are rounded. 
     
     
         26 . A mould as claimed in  claim 25  in which the rounded bases have a radius of 20 mm. 
     
     
         27 . A mould as claimed in  claim 21  in which corners formed where the cavity side walls meet each other are rounded. 
     
     
         28 . A mould as claimed in  claim 27  in which the side wall corners have a radius of 10 mm. 
     
     
         29 . A mould as claimed in  claim 21  in which edges formed where the cavity side walls meet an 30 upper surface of the mould are rounded. 
     
     
         30 . A mould as claimed in  claim 29  in which the side wall-mould upper surface edges have a radius of 1 mm. 
     
     
         31 . A mould as claimed in  claim 21  in which bottom corners, formed where the cavity side walls meet the cavity base, are rounded. 
     
     
         32 . A mould as claimed in  claim 31  in which the side wall-base bottom corners have a radius of 10 mm. 
     
     
         33 . A mould as claimed in  claim 31  in which air bores are located in the side walls base bottom corners. 
     
     
         34 . A mould as claimed in  claim 33  in which the air bores have a diameter of 0.1 mm to 1 mm. 
     
     
         35 . A mould as claimed in  claim 34  in which the air bores have a diameter of 0.4 mm to 0.5 mm. 
     
     
         36 . A mould as claimed in  claim 21  in which the shortest dimension of the planar surface between two adjacent cavities lies in the range of 4 mm to 10 mm and between an edge of the mould and the closest cavity lies in the range of 2 mm to 5 mm. 
     
     
         37 . A mould as claimed in  claim 21  in which a continuous strip of uninterrupted planar surface is provided between adjacent rows of cavities. 
     
     
         38 . A mould as claimed in  claim 21  in which a continuous strip of uninterrupted planar surface is provided between every other pair of adjacent rows of cavities. 
     
     
         39 . A mould as claimed in  claim 21  in which air bores are located. 
     
     
         40 . A container formed by the process of any one of the preceding claims.