Apparatus for continuously forming vacuum packaged body

Abstract

An apparatus for vacuum packaging a continuous packaged body of the invention is so constructed that a seal bar 35 and a seal table 36 are mounted in the respective skirt parts 39, 40 of seal blocks 22, 23 opposite to each other with a tube film 20 interposed between them, and in the case of nipping the tube film 20 by both seal blocks 22, 23 plural intermittent teeth 44. 45 spot close the tube film on the inner sides of both skirt parts as one points in the transfer direction of a material to be packaged. Simultaneously, in ports 47 of the face of a standing gap 46 formed thin along the outsides of the above intermittent teeth, the tube film is flared by vacuum suction force, and from the section of the tube film cut by forcing a cutting edge 51 in the seal bar into a receiving groove 52 cut in the seal table, the air in the tube film is sucked through the spot closing gap and the receiving groove 52. By spot closing the tube film by the above intermittent teeth 44, 45, distortion of the film in displacement and suction of the air is restrained, and then the cut end of the tube film is heat sealed by the seal bar 35 and the seal table 36.

What is claimed is:  
     
         1 . A packaging apparatus, comprising a seal bar and a seal table disposed in the midway of a track for transferring a tube film storing materials to be packaged at equal spaces in a column along the longitudinal direction for sealing said tube film in the direction right-angled to the track direction, wherein said packaging apparatus comprises: 
 (a) a pair of seal blocks surrounding said seal bar and seal table outside the opposite surfaces of said seal bar and seal table respectively by the skirt parts thereof and supporting the same;    (b) means for spot closing said tube film by plural intermittent teeth on the inner sides of said skirt parts as one points in the transfer direction of materials to be packaged while the respective skirt part edges of both of said seal blocks nip said tube film corresponding to the pitch transfer of said materials to be packaged;    (c) a sub-vacuum line for applying vacuum suction force to each port formed on a standing gap to flare said tube film at said standing gap formed thin along the outsides of said intermittent teeth;    (d) a main vacuum line for forcing a cutting edge stably disposed in the middle of the interior of said seal bar into a receiving groove cut in said seal table to cut said tube film in an area surrounded by said skirt parts, and sucking the air in a bag in front of said seal blocks through said spot closing gap from said seal bar and said seal table through said receiving groove in said seal table; and    (e) means for welding the cut sides of said tube film by the relative approach of said seal bar and said seal table after said removal of air.    
     
     
         2 . The apparatus according to  claim 1 , wherein corresponding to the operation of nipping said tube film between two front and rear materials to be packaged in said tube film by a pair of movable blocks, first a first opening and closing valve mounted between said sub-vacuum line and a vacuum pump is opened, and then a second opening and closing valve mounted between said main vacuum line and said vacuum pump is opened.  
     
     
         3 . The apparatus according to  claim 2 , wherein said sub-vacuum line and said main vacuum line are connected to said vacuum pump through a vacuum tank.  
     
     
         4 . The apparatus according to  claim 1 , wherein intermittent teeth formed by said skirt parts of said seal blocks are provided with cooling means for inhibiting transfer of heating heat of said seal bar mounted in the interior of said skirt part.  
     
     
         5 . The apparatus according to  claim 1 , wherein simultaneously with nipping said tube film by both of said seal blocks, a material to be packaged in front of said seal blocks is pushed and supported by blocks made of urethane foam.  
     
     
         6 . A packaging apparatus for sealing a tube film that surrounds a plurality of spaced packages moving in a transfer direction, said seal being perpendicular to said transfer direction, said packaging apparatus comprising: 
 (a) an upper seal block and a lower seal block positioned above and below the plurality of packages, at least one of the seal blocks being moveable between an open and a closed position, each of said seal blocks having a slot formed therein and a skirt portion surrounding the slot, wherein the skirt portion has an input side and an output side, each being formed such that when the upper and lower seal blocks are in the closed position, a substantially continuous seal line is formed across the tube film at the input side, and a gap is formed along the output side;    (b) a plurality of intermittently spaced nipping teeth formed along the output side of the skirt portion to nip the tube film at the output side, said nipping teeth being positioned so as to form one or more ports between the upper and lower sealing blocks along the gap when the upper and lower seal blocks are in the closed position;    (c) a sub-vacuum line through which a vacuum suction force to each port is produced to maintain the tube film open within each of the ports when the upper and lower seal blocks are in the closed position;    (d) a main vacuum line through which a substantial vacuum is produced within the package positioned adjacent to the output side when the upper and lower seal blocks are in the closed position;    (e) a seal bar positioned with the slot formed in one of either the upper or lower seal blocks, and a seal table positioned within the slot formed in the other seal block, wherein at least one of said seal bar or seal table is moveable to a sealing position to seal the tube film there between;    (f) a sealing element to form a first seal along a trailing edge of a package positioned at the output side and a second seal along a leading edge of a package positioned at the input side, said seals being made after the substantial vacuum is produced in the package positioned adjacent to the output side; and    (g) a cutting tool to transversely cut the tube film after the seals are formed.    
     
     
         7 . The apparatus according to  claim 6 , further comprising a sub-vacuum valve positioned between the sub-vacuum line and a vacuum pump, and a main vacuum valve positioned between the main vacuum line and the vacuum pump, wherein the sub-vacuum valve is opened to draw the vacuum suction force to each port before the main vacuum valve is opened to draw the substantial vacuum in the package.  
     
     
         8 . The apparatus according to  claim 7 , wherein said sub-vacuum line and said main vacuum line are connected to said vacuum pump through a vacuum tank.  
     
     
         9 . The apparatus according to  claim 6 , further comprising cooling means positioned near the intermittent teeth at the output side of the upper and lower sealing blocks for inhibiting heat transfer of said seal bar in the slot of the seal block.  
     
     
         10 . The apparatus according to  claim 6 , further comprising at least one push block positioned so that simultaneously with the tube film being nipped by the intermittent teeth on both of said seal blocks, a material to be packaged in front of said seal blocks is pushed and supported by the at least one push block.  
     
     
         11 . The apparatus according to  claim 10 , wherein the at least one push block comprises a urethane foam.  
     
     
         12 . The apparatus according to  claim 6 , wherein the intermittent teeth are formed on attachment blocks that are mounted on the output side of the skirt portion of each of the upper and lower seal blocks.  
     
     
         13 . The apparatus according to  claim 6 , wherein the sub-vacuum line comprises a plurality of passages that communicate between the sub-vacuum line and spaces formed between adjacent intermittent teeth.  
     
     
         14 . The apparatus according to  claim 12 , wherein the sub-vacuum line comprises a plurality of passages formed in the attachment blocks that communicate between the sub-vacuum line formed in the upper and lower seal blocks and spaces formed between adjacent intermittent teeth.  
     
     
         15 . A method of evacuating a section of a linear tube formed of two layers of film containing material which is stored in spaced apart sections extending along the length of the tube, comprising: 
 (a) clamping the layers of film between sets of intermittent teeth positioned transverse and at the end of a section of the tube;    (b) applying a first vacuum to the outer surface of those parts of both layers of film located between said teeth so as to cause such parts outer surfaces to form passages communicating with the interior of the section of said tube adjoining and extending outwardly from said teeth;    (c) applying a second vacuum to said passages so as to exhaust air from said adjoining section of said tube; and    (d) sealing said one end of said adjoining section following exhausting of said air.