Method And Machine For Forming A Sealed Wrapping About An Article, And Package So Formed

Abstract

A method of forming a sealed wrapping about an article, whereby a sheet of wrapping material is folded and sealed about the article to form a substantially tubular partial wrapping having two open ends, and a sealing flap projecting outwards crosswise to the partial wrapping; the sealing flap is folded onto a major lateral portion of the partial wrapping; and the open ends of the partial wrapping are then gripped and sealed.

1 . A method of forming a sealed wrapping ( 2 ) about an article ( 3 ), the method comprising the steps of:
 folding a sheet ( 7 ) of wrapping material about the article ( 3 ), so the folded sheet ( 7 ) has a pair of facing, substantially parallel, projecting flaps ( 19 ,  19 ′);   superimposing and sealing the pair of flaps ( 19 ,  19 ′) to form a substantially tubular partial wrapping ( 21 ) having two open ends ( 22 ), and a first sealing flap ( 23 ) projecting outwards crosswise to the partial wrapping ( 21 );   folding the first sealing flap ( 23 ) onto an outer surface of the partial wrapping ( 21 );   successively gripping and sealing the open ends ( 22 ) of the partial wrapping ( 21 );   deforming at least one of the open ends ( 22 ) of the partial wrapping ( 21 ) by means of a retractor ( 38 ), to form two facing flaps; and gripping and sealing the facing flaps to form a respective closed end portion ( 10 ) and a second sealing flap ( 35 ), which projects from the end portion ( 10 ) and defines a seal of the end portion ( 10 );   folding the second sealing flap ( 35 ) onto the end portion ( 10 ) so that two tabs ( 46 ) of the second sealing flap ( 35 ) project laterally from the end portion ( 10 ) and on opposite sides of the end portion ( 10 ); and   folding each tab ( 46 ) onto the end portion ( 10 ).   
     
     
         2 . A method as claimed in  claim 1 , wherein the sheet ( 7 ) of wrapping material is folded and sealed about the article ( 3 ) so that the partial wrapping ( 21 ) comprises two major lateral portions ( 8 ) on opposite sides of the article ( 3 ); and two minor lateral portions ( 9 ) which are located on opposite sides of the article ( 3 ), are crosswise to the major lateral portions ( 8 ), and are connected to the major lateral portions ( 8 ) by respective lateral edges ( 24 ); the first sealing flap ( 23 ) extending substantially along a respective lateral edge ( 24 ), and being folded onto one of the major lateral portions ( 8 ) of the partial wrapping ( 21 ); and the open ends ( 22 ) of the partial wrapping ( 21 ) being closed and sealed by gripping them to form two second sealing flaps ( 35 ) substantially crosswise to the first sealing flap ( 23 ) and to the minor lateral portions ( 9 ). 
     
     
         3 . A method as claimed in  claim 2 , wherein the first sealing flap ( 23 ) is first folded to project substantially perpendicularly to the relative said major lateral portion ( 8 ), is maintained in that position, and is subsequently folded onto the relative major lateral portion ( 8 ). 
     
     
         4 . A method as claimed in  claim 2 , wherein the article ( 3 ) comprises two substantially opposite end walls ( 4 ); two substantially opposite major lateral walls ( 5 ) crosswise to the end walls ( 4 ); and two minor lateral walls ( 6 ) crosswise to the end walls ( 4 ) and to the major lateral walls ( 5 );
 the sheet ( 7 ) being folded and sealed so each major lateral portion ( 8 ) of the partial wrapping ( 21 ) is located at a respective major lateral wall ( 5 ), and each minor lateral portion ( 9 ) of the partial wrapping is located at a respective minor lateral wall ( 6 ).   
     
     
         5 . (canceled) 
     
     
         6 . (canceled) 
     
     
         7 . A method as claimed in  claim 1 , wherein the tabs ( 46 ) are folded onto the end portion as the sheet ( 7 ), folded about the article ( 3 ), is fed in a direction substantially parallel to said end portion ( 10 ) and to said tabs ( 46 ), and in particular crosswise to the major lateral portions ( 8 ). 
     
     
         8 . A method as claimed in  claim 1 , wherein the tabs ( 46 ) are substantially folded roughly 180° onto the end portion ( 10 ), by each sliding along a respective rail ( 47 ) of a folding device ( 42 ). 
     
     
         9 . A package comprising an article ( 3 ), and a sealed wrapping ( 2 ) folded about the article ( 3 ); the wrapping ( 2 ) comprising two major lateral portions ( 8 ), two minor lateral portions ( 9 ) crosswise to the major lateral portions ( 8 ), and two end portions ( 10 ) crosswise to the major and minor lateral portions ( 8 ,  9 ); the wrapping ( 2 ) being characterized by comprising a first seal at one of the major  5  lateral portions ( 8 ), and second seals which are crosswise to the first seal and each located at a respective end portion ( 10 );
 the first seal comprising a first sealing flap ( 23 ) folded onto the respective major lateral portion ( 8 ); and each second seal comprises a second sealing flap ( 35 ) folded onto the respective end portion ( 10 ). 
 
     
     
         10 . (canceled) 
     
     
         11 . A package as claimed in  claim 9 , wherein each second sealing flap ( 35 ) comprises two tabs ( 46 ) folded onto the respective end portion ( 10 ). 
     
     
         12 . A package as claimed in  claim 9 , wherein the wrapping ( 2 ) is obtained using a method that includes:
 folding a sheet ( 7 ) of wrapping material about the article ( 3 ), so the folded sheet ( 7 ) has a pair of facing, substantially parallel, projecting flaps ( 19 ,  19 ′);   superimposing and sealing the pair of flaps ( 19 ,  19 ′) to form a substantially tubular partial wrapping ( 21 ) having two open ends ( 22 ), and a first sealing flap ( 23 ) projecting outwards crosswise to the partial wrapping ( 21 );   folding the first sealing flap ( 23 ) onto an outer surface of the partial wrapping ( 21 );   successively gripping and sealing the open ends ( 22 ) of the partial wrapping ( 21 );   deforming at least one of the open ends ( 22 ) of the partial wrapping ( 21 ) by means of a retractor ( 38 ), to form two facing flaps; and gripping and sealing the facing flaps to form a respective closed end portion ( 10 ) and a second sealing flap ( 35 ), which projects from the end portion ( 10 ) and defines a seal of the end portion ( 10 );   folding the second sealing flap ( 35 ) onto the end portion ( 10 ) so that two tabs ( 46 ) of the second sealing flap ( 35 ) project laterally from the end portion ( 10 ) and on opposite sides of the end portion ( 10 ); and   folding each tab ( 46 ) onto the end portion ( 10 ).   
     
     
         13 . A machine for forming a sealed wrapping ( 2 ) about an article ( 3 ), the machine ( 1 ) comprising:
 a first folding device ( 12 ) for folding a sheet ( 7 ) of wrapping material into a U about the article ( 3 ), so the folded sheet ( 7 ) has a pair of facing, substantially parallel, projecting flaps ( 18 ,  19 ,  19 ′) on each free side of the article ( 3 );   a first sealing device ( 20 ) for superimposing and sealing the flaps ( 19 ,  19 ′) in one pair to form a substantially tubular partial wrapping ( 21 ) having two open ends ( 22 ), and a first sealing flap ( 23 ) projecting outwards crosswise to the partial wrapping ( 21 ); a second folding device ( 28 ) for folding the first sealing flap ( 23 ) onto an outer surface of the sheet ( 7 );   a second sealing device ( 39 ) for sealing the open ends ( 22 ) of the partial wrapping ( 21 );   at least one retractor ( 38 ) for deforming at least one of the open ends ( 22 ) of the partial wrapping ( 21 ) to define two facing flaps; the second sealing device ( 39 ) gripping and sealing said facing flaps to form a respective closed end portion ( 10 ) and a second sealing flap ( 35 ), which projects from the end portion ( 10 ) and defines a seal of the end portion ( 10 ); and   a third folding device ( 42 ) for folding the second sealing flap ( 35 ) onto the relative end portion ( 10 ) so that two tabs ( 46 ) of the second sealing flap ( 35 ) project laterally on opposite sides of the end portion ( 10 ); the third folding device ( 42 ) also folding each tab ( 46 ) onto the end portion ( 10 ).   
     
     
         14 . A machine as claimed in  claim 13 , wherein the first folding device ( 12 ) and the first sealing device ( 20 ) fold and seal the sheet ( 7 ) about the article ( 3 ) so the partial wrapping ( 21 ) comprises two major lateral portions ( 8 ) on opposite sides of the article ( 3 ); and two minor lateral portions ( 9 ) which are located on opposite sides of the article ( 3 ), are crosswise to the major lateral portions ( 8 ), and are connected to the major lateral portions ( 8 ) by respective lateral edges ( 24 ); the first sealing flap ( 23 ) extending along a respective lateral edge ( 24 ); the second folding device ( 28 ) folding the first sealing flap onto one of the major lateral portions ( 8 ) of the partial wrapping ( 21 ); and the second sealing device ( 39 ) comprising at least 10 one gripping unit for closing and sealing the open ends ( 22 ) of the partial wrapping ( 21 ) to form two second sealing flaps ( 35 ) crosswise to the first sealing flap ( 23 ) and to the minor lateral portions ( 9 ). 
     
     
         15 . A machine as claimed in  claim 14 , wherein the gripping unit comprises two heat-seal jaws ( 41 ). 
     
     
         16 . A machine as claimed in  claim 13 , wherein the first folding device ( 12 ) comprises at least one pocket ( 16 ); and a push unit ( 13 ) for feeding the article ( 3 ), crosswise to the sheet ( 7 ), into the pocket ( 16 ), so the sheet ( 7 ) is pushed into the pocket ( 16 ) by the article ( 3 ) and folded into a U about the article ( 3 ). 
     
     
         17 . (canceled) 
     
     
         18 . (canceled) 
     
     
         19 . A machine as claimed in  claim 16 , further comprising a conveyor ( 43 ) for feeding the article ( 3 ), in a direction crosswise to the second sealing flap ( 35 ) projecting from the end portion ( 10 ), along a portion of a feed path (P), which portion is located downstream from the second sealing device ( 39 ) and at the third folding device ( 42 ); the third folding device ( 42 ) comprising at least one substantially fixed member ( 44 ) which intercepts the second sealing flap ( 35 ) to fold the second sealing flap ( 35 ) onto the end portion ( 10 ). 
     
     
         20 . A machine as claimed in  claim 13 , wherein the third folding device ( 42 ) comprises at least two rails ( 47 ) designed so that each tab ( 46 ), as it slides along the relative rail ( 47 ), is folded roughly 180° onto the relative end portion ( 10 ). 
     
     
         21 . A method as claimed in  claim 1 , wherein a rail ( 47 ) comprises a first portion ( 48 ) which folds a respective tab ( 46 ) approximately 90° into a position substantially perpendicular to respective end portion ( 10 ); and a second portion ( 49 ), after portion ( 48 ), for folding tab ( 46 ) onto end portion ( 10 ). 
     
     
         22 . A method as claimed in  claim 1 , wherein a folding device ( 42 ) is provided for folding the tabs and comprises four flip-over rails ( 47 ), each designed so that each tab, as it slides along respective rail ( 47 ), is folded roughly 180° onto respective end portion ( 10 ).