Method and apparatus for form-fill-seal packaging of articles

Vertical form-fill-seal packaging apparatus comprising

• means for forming flexible packaging material into a downwardly extending tubing;
• means for feeding the tubing downwardly at a first continuously downward feeding speed;
• means for longitudinally sealing the tubing;
• means for cross-sealing the tubing at package length intervals;
• means for filling the tubing with material between successive cross seals;
• said cross sealing means comprising
• a pair of sealing members (40;
• 43);
• seal moving means for moving said cross-sealing members relative to one another between an open position clear of the tubing and a fully closed position in sealing engagement with the tubing;
• stripper members (87) movable relative to one another from an open position to a closed position in engagement with and squeezing the tubing;
• and means for moving said stripping means up and down relative to the tubing,
• wherein said stripper members comprise housing means and stripper plates movable radially with respect to said tubing, said housing means being fixed positioned adjacent and below said cross sealing means;
• said means for moving said stripper members up and down being coupled to said cross-sealing means for conjoint movement said stripper member moving means moving the stripper members and the cross-sealing means conjointly in a continuously downward direction, first at a second speed in excess of said continuous feeding speed of said tubing to squeeze the tubing between said stripper members and to compact said material within said tubing in advance of sealing engagement of said cross sealing means with said tubing, and then, at the end of a stripping path, said means for moving said stripper members and cross-sealing means move with said first speed,
• said seal moving means then moving said cross-sealing members in the fully closed sealing position and the stripper plates simultaneously into a tubing squeeze position;
• means for controlling the cross sealing members to effect a cross seal during continuous movement of the tubing and the cross-sealing members at said first speed;
• said means for conjoint movement of said stripper members and cross-sealing members and said seal moving means then moving said members in open position and in a path out-of-engagement with said tubing and in a direction counter the feeding direction of said tubing.

Method for form-filling and sealing packaging of articles including

• providing a flat flexible film (2) having longitudinal spaced markers (53);
• continuously positively feeding the flat film (2) to a former by a continuously moving feeding means (7, 10), and passing the flat flexible film around the former (12) to deform and shape the flat film into tubular shape, in which lateral edge portions (20a, 20b, 20c) of the film will be located adjacent each other;
• connecting the longitudinal edge portions of the film while in tubular shape to form a closed tube with a vertical longitudinal seal (16);
• forming two spaced transverse cross seams (17, 21) across the closed tube by sealing or welding means (40, 43) at package length;
• filling the tube after having been cross-sealed by one of said seams;
• severing the tube between the cross seams,
• and comprising the steps of
• sequentially engaging a longitudinal sealing or welding jaw (15) against the longitudinal edge portions of the moving film to thereby connect the longitudinal edge portions, and
• repetitively moving said longitudinal sealing jaw in a straight path portion in engagement with said edge portions of the moving film to seal the edge portions by continued engagement with the film during its downward movement, and further moving said sealing jaw in a return path portion out-of-engagement with said edge portions and counter the feeding direction of said tube (20);
• continuously positively exerting a drawing force on the closed tube (20) by continuously drawing the closed tube downwardly over the former at a constant speed during formation of said longitudinal seal;
• filling the tube with a quantity of said articles, downwardly by gravity, and with which the packages are to be filled during the downward movement of said tube;
• moving a pair of sealing or welding means (40, 43) relative to one another between an open and a closed position to form said transverse seams (17, 21) and, when in closed position, additionally moving said sealing or welding means in vertical direction along a straight path at the same speed as the speed of the moving tubing;
• repetitively moving the sealing or welding means, when in open position, in a return path out-of-engagement with said tubing and counter the feeding direction of said tubing;
• scanning the spaced markers (53) on the film, as it is being continuously fed, by a scanning means (19);
• comparing the time of passage of sequential markers past a scanning point with a predetermined command reference value;
• and controlling, in synchronized relation:
• the feeding speed of the film during the feeding steps;
• the movement speed of the sealing means;
• the formation of the cross seals, to conform to said predetermined command reference value,
• to thereby control, in synchronized relation:
• the movement of the feeding means (7, 10);
• the movement of the welding jaw (15);
• and
• the sealing or welding operation of the sealing or welding means (40, 43),
• to compensate for deviation between feed of the film by said feeding means and movement and sealing operation of said sealing means.

A method for form-fill-seal and package articles including

• forming a flexible packaging material into a downwardly extending tubing,
• continuously, positively feeding said tubing in continuous movement with a constant first speed in a downward direction,
• forming a longitudinal seal on said tubing during said continuous movement of said tubing;
• filling the tubing downwardly with a quantity of the articles with which the packages are to be filled;
• transversely sealing the tubing at package length,
• the transverse seals being formed by a pair of sealing members (40, 43) movable relative to one another between an open and a closed position, and, when the sealing members are in closed position, moving said sealing members in a straight path in vertical direction with the same first speed of the tubing to thereby form a vertical seal, and
• when the sealing members are in open position and after delivery of the articles into the tubing and before a next seal is made, squeezing the tubing below the sealing members by positively moving a pair of stripper members (87) and operatively connected with said sealed members (40, 43) and closely adjacent relative to one another on opposite sides of the tubing into a closed position;
• moving simultaneously said pair of sealing members into a position adjacent one another but slightly spaced in a non-sealing relation to the tubing,
• holding the stripper members in their closed position while moving them generally straight downwardly along the tubing together with the slightly spaced sealing members with a second speed which is higher than said first speed
• and upon downward movement of said tubing, to thereby compress the product in the tubing below the level of the next seal to be made;
• reducing the vertical speed of said operatively connected sealing members and said stripper members to said first speed and fully closing the sealing members on the tubing above the stripper members for forming said transverse seals during movement of the tubing with said first speed;
• cutting said sealed package;
• and
• then opening the stripper members and the sealing members and moving the stripper members together with the sealing members to their open position, and further counter the direction of movement of the tubing for return to a starting position.

Vertical form-fill-seal packaging apparatus having

• means (3) for providing a continuous, flat, flexible film (2) having spaced markers (53) thereon;
• a former (12) receiving said flat, flexible film and deforming said flat, flexible film into tubular shape, with lateral edge portions of the flat film located adjacent each other;
• means (15) sealing or welding the longitudinal edge portions (20a, 20b) of the film, while in tubular form, to form a longitudinal closed tube (20) with a longitudinal seal (16);
• cross-sealing means (40, 43) for forming two spaced cross seals (17, 21) across the closed tube (20);
• means (14, 13) for filling the tube after having been cross-sealed by one of said cross seals;
• means (72) for severing a filled tube portion from the closed tube by engagement of a severing knife (72) between said spaced seals;
• wherein the film (2) is formed with longitudinally spaced markers (53);
• and said apparatus further comprises
• continuously operating positive feeding means (7, 25) for feeding the film to the former (12) and pulling the then formed tube (20) from the former;
• a forming tube (13) positioned downstream--with respect to movement of said film--of said former (12) for shaping and wrapping the film into said tubular shape,
• said continuously positive feeding means comprising means (25) for engaging the film as it is wrapped about said forming tube (13) and maintaining said film in taut condition, said engaging means exerting a pulling force on said film,
• a sealing means drive means (58, 59) for continuously moving the sealing means (40, 43) as the film is being fed to the former;
• said means for connecting, sealing or welding the longitudinal edge portions (20a, 20b, 20c) of the film and forming said longitudinal seal (16) comprising a connecting, sealing or welding jaw (15), and jaw drive means (70) moving said jaw in a elliptical path (18) having a vertical component substantially parallel to and in the direction of movement of said film edge portions with the speed of feeding of said film (2) and another component, removed from said film edge portion;
• means (62, 76, 80, 82) for moving said cross sealing means (40, 43) between an open position and a closed position and diametrically across said film tubing (20),
• drive means (58, 59) moving said cross sealing means (40, 43) longitudinally with the film in a straight path at the vertical downward feeding speed of said film tube (20) upon closing of said cross sealing means with the film tube and repetitively moving said cross sealing means in a return path out-of-engagement with said tubing and counter the continuously feeding direction of said tubing (20);
• a scanning means (19) positioned at a predetermined location in said apparatus and in scanning alignment with said markers (53) on the film, for scanning the markers as the film is moved past the scanning means;
• and control means including comparator means (84, 90, 86, 88, 65) coupled to said scanning means and said continuous positive film feeding means, said sealing means drive means (58, 60) and said cross-sealing means (40, 43) and controlling movement of all said connected means, in synchronous relation, as a function of comparison of the spacing of sensed marker with respect to a predetermined command interval,
• wherein said comparator means compares the time interval between sensing of said spaced markers by said sensing means;
• and wherein the operating speed of said jaw drive means is controlled by said control means.

Vertical form-fill-seal packaging apparatus having

• a supply roll (3) of flat, flexible film, wherein the film (2) is formed with longitudinally spaced markers (53);
• means for forming said film into a downwardly extending tubing,
• first transport means (7) for continuously drawing said film from said supply roll (3);
• second transport means (25) for drawing said material continously over a former (12), and at sufficient tension to maintain it taut and at a predetermined downward speed;
• means (15) for forming a longitudinal vertical seal on the tubing during continuously moving said tubing, and said forming means comprising a jaw and drive means for said jaw to move it in a straight path parallel to the feeding movement of said tubing;
• a pair of cross-sealing means (40, 43) for forming cross seals across said tubing,
• first drive means (62, 76, 78, 82) for moving said cross-sealing means (40, 43) between an open position and a closed position,
• second drive means (58, 59) coupled to said cross-sealing means for continuously moving said cross-sealing means (40, 43) in vertical direction;
• stripping means (85, 87) operatively associated with and coupled to said cross-sealing means (40, 43) and including stripping members (87) movable radially inwardly with respect to said tubing (20), said second drive means first moving the cross-sealing means and the stripping means longitudinally with respect to said film at a speed in excess of the continuous feeding speed of said film to squeeze the tubing between said stripping members to and compact material within said tubing;
• said second drive means (58, 59), after said longitudinal movement at a speed in excess of the film speed, moving said stripping means (85, 87) in squeezed condition and said cross-sealing means in closed position at said same downward speed of said tubing for cross-sealing the tubing,
• means (14) for filling the tubing between successive cross seals;
• means (72) for severing a filled tubing;
• means (19) for sensing the markers (53) on the film;
• means for comparing the length of the film sheet between two successive markers (53) with a predetermined command length, and
• a correcting device connected to and controlling at least one of said transport means (7, 25) for adjusting deviations of the film transport speed in order to prevent accumulated inaccurate feeding of the tubing.