Single-lobe filter bag for infusion products

Abstract

A single-lobe filter bag for infusion products comprises a length ( 2 ) of filter material forming a chamber ( 3 ) containing a charge ( 4 ) of the infusion product. The length ( 2 ) comprises: a first closed top end ( 5 ) formed by a first join (S 1 ) between two first end edges of the length ( 2 ); a second closed bottom end ( 7 ) and two sides ( 8, 9 ) connecting the two ends ( 5, 7 ) of the length ( 2 ); the two sides ( 8, 9 ) connecting the first and second edges ( 5, 7 ) are at least partly folded onto each other to form a fold towards the inside of the chamber ( 3 ) and the second bottom end ( 7 ) of the filter bag ( 1 ) is closed by second join (S 2 ) designed to form a rigid flat bottom surface ( 11 ) of the filter bag ( 1 ) such as to define a stable base, with a substantially triangular cross section, for supporting the filter bag ( 1 ).

1 . A single-lobe filter bag for infusion products, the filter bag ( 1 ) comprising a length ( 2 ) of filter material forming a chamber ( 3 ) containing a charge ( 4 ) of the infusion product; the length ( 2 ) comprising at least:
 a first closed top end ( 5 ) formed by a first join (S 1 ) between two first end edges of the length ( 2 );   a second closed bottom end ( 7 );   two sides ( 8 ,  9 ) connecting the first end ( 5 ) and the second end ( 7 ) of the length ( 2 ), the filter bag ( 1 ) being characterised in that:   the two sides ( 8 ,  9 ) connecting the first and second edges ( 5 ,  7 ) are at least partly folded onto each other to form a fold towards the inside of the chamber ( 3 ); and   the second bottom end ( 7 ) of the filter bag ( 1 ) is closed by a second join (S 2 ) designed to form a stiff flat bottom surface ( 11 ) of the filter bag ( 1 ) such as to define a stable base, with a substantially triangular cross section, for supporting the filter bag ( 1 ).   
   
   
       2 . The filter bag according to  claim 1 , characterised in that the second end ( 7 ) has two second edges ( 7   a ,  7   b ) folded one over the other and joined along the bottom end ( 7 ) in such a way as to directly define the bottom supporting base ( 11 ). 
   
   
       3 . The filter bag according to  claim 1 , characterised in that the second end ( 7 ) comprises two second edges ( 7   a ,  7   b ) folded one over the other and joined at the bottom ends ( 8   a ,  8   b ;  9   a ,  9   b ) of the connecting sides ( 8 ,  9 ) in such a way as to obtain a continuous bottom surface ( 11 ) defining the bottom supporting base. 
   
   
       4 . The filter bag according to  claim 2 , characterised in that the second edges ( 7   a ,  7   b ) define a central extension of the second bottom end ( 7 ); said second edges ( 7   a ,  7   b ) positioned face to face with each other and joined in such a way as to form a tab ( 12 ) that protrudes from the bottom supporting base ( 11 ) and is elastically compliant in such a way as to be folded onto the bottom base ( 11 ) to increase its stiffness. 
   
   
       5 . The filter bag according to  claim 4 , characterised in that the tab ( 12 ) is folded and joined stably by a seal (S 4 ) to the bottom supporting base ( 11 ), thus forming a larger, stiff longitudinal area. 
   
   
       6 . The filter bag according to  claim 2 , characterised in that the ends of each of the two second edges ( 7   a ,  7   b ) closer to the sides ( 8 ,  9 ) are folded towards the inside of the chamber ( 3 ) to form a bevelled shape and are flattened on the corresponding area of the other edge ( 7   a ,  7   b ) in such a way as to create the stiff supporting base ( 11 ) at the second end ( 7 ). 
   
   
       7 . The filter bag according to  claim 3 , characterised in that the ends of each of the two second edges ( 7   a ,  7   b ) are folded towards the first end ( 5 ), which is placed over the respective end of the other edge ( 7   a ,  7   b ) and at the respective bottom ends ( 8   a ,  8   b ;  9   a ,  9   b ) of the connecting sides ( 8 ,  9 ) of the length ( 2 ) in such a way as to form a bevelled shape; each pair of ends of the second edges ( 7   a ,  7   b ) being joined to each other by a seal (S 2 ) together with the respective bottom ends ( 8   a ,  8   b ;  9   a ,  9   b ) of the connecting sides ( 8 ,  9 ), thus creating a stiff lateral area of the length ( 2 ) in order to form wide supporting shoulders for the closed bottom supporting base ( 11 ) of the filter bag ( 1 ). 
   
   
       8 . The filter bag according to  claim 1 , characterised in that it comprises, on the length ( 2 ), a string ( 13 ) joined by sealing one end of it to the length ( 2 ) itself and the other end to a tag ( 14 ) which is in turn removably associated with the length ( 2 ) of filter material. 
   
   
       9 . The filter bag according to  claim 1 , characterised in that the length ( 2 ) of filter material is made from filter paper. 
   
   
       10 . The filter bag according to  claim 1 , characterised in that the length ( 2 ) of filter material is made from biodegradable material. 
   
   
       11 . The filter bag according to  claim 1 , characterised in that the length ( 2 ) of filter material is made from non-biodegradable plastic material. 
   
   
       12 . The filter bag according to  claim 1 , characterised in that the joins on the length ( 2 ) of filter material are defined by a first seal (S 1 ) and a second seal (S 2 ) made by heat sealing. 
   
   
       13 . The filter bag according to  claim 1 , characterised in that the joins on the length ( 2 ) of filter material are defined by a first seal (S 1 ) and a second seal (S 2 ) made using glue. 
   
   
       14 . The filter bag according to  claim 1 , characterised in that the joins on the length ( 2 ) of filter material are defined by a first seal (S 1 ) and a second seal (S 2 ) made by ultrasound sealing. 
   
   
       15 . The filter bag according to  claim 1 , characterised in that the corners ( 5   a ,  5   b ) of the first, top end ( 5 ) of the length of filter paper are bevelled symmetrically according to an angle (α). 
   
   
       16 . The filter bag according to  claim 1 , characterised in that the tubular length ( 2 ) has an initially open tubular shape, with a central join for closing the tube and defined by a third seal (S 3 ). 
   
   
       17 . The filter bag according to  claim 1 , characterised in that it comprises, on the length ( 2 ), a string ( 13 ) joined, at one end, by a knot (A 1 ) to the length ( 2 ) itself and, at the other end, by a knot (A 2 ) to a tag ( 14 ), the string ( 13 ) being looped around the length ( 2 ). 
   
   
       18 . The filter bag according to  claim 1 , characterised in that it comprises, on the length ( 2 ), a string ( 13 ) joined, at one end, by a knot (A 1 ) to the length ( 2 ) itself and, at the other end, by a knot (A 2 ) to a tag ( 14 ), which is in turn removably attached to the length ( 2 ), the string ( 13 ) being looped around the length ( 2 ). 
   
   
       19 . The filter bag according to  claim 16 , characterised in that the tag ( 14 ) has a slit ( 14   f ) at the top of it for engaging an end portion (P) of the string ( 13 ) knotted to the length ( 2 ) of filter material in such a way as to hold it against the length ( 2 ).