VERTICAL-FLOW WRAPPER AND METHOD TO PRODUCE A BAG

Abstract

A vertical flow-wrapper that includes a form-fill-tube along which a film is transported in a transport direction and formed into a film tube; a longitudinal-sealing means, which seals two opposing longitudinal ends of the film tube together to form a longitudinal seal, the longitudinal-sealing means includes a seal jaw and a pair of guiding rollers provided upstream from the seal jaw to guide the two opposing longitudinal ends of the film tube through the seal jaw and pressing means to press the two opposing longitudinal ends of the film tube together; and a cross-sealing means and a cutting means which provide cross seals to each package and separate the packages from each other; an axis of rotation of the pair of guiding rollers are provided parallel to a transportation plane of the two opposing longitudinal ends of the formed film and not perpendicular to the transport direction.

Claims

1. A vertical flow-wrapper comprising: a form-fill-tube along which a film is transported in a transport direction and formed into a film tube, a longitudinal-sealing means, which seals two opposing longitudinal ends of the film tube together to form a longitudinal seal, the longitudinal-sealing means comprising a seal jaw and a pair of guiding rollers provided upstream from the seal jaw to guide the two opposing longitudinal ends of the film tube through the seal jaw and pressing means to press the two opposing longitudinal ends of the film tube together to form the longitudinal seal, a cross-sealing means and a cutting means which provide cross seals to each package and separate the packages from each other, and wherein an axis of rotation of the pair of guiding rollers are provided parallel to a transportation plane of the two opposing longitudinal ends of the formed film and not perpendicular to the transport direction.

2. The vertical flow-wrapper according to claim 1, wherein the pair of guiding rollers stretch the film in a transversal direction.

3. The vertical flow-wrapper according to claim 1, wherein the vertical flow-wrapper comprises a reclosing means sealing means to fix a reclosing means at the film parallel to the longitudinal seal.

4. The vertical flow-wrapper according to claim 3, wherein the reclosing means sealing means comprises a pressing means and/or a seal jaw.

5. The vertical flow-wrapper according to claim 4, wherein the pressing means is two pairs of rollers, each pair provided on one axis.

6. The vertical flow-wrapper according to claim 1, wherein the longitudinal-sealing means comprises a pressing means and/or a pair of rollers.

7. The vertical flow-wrapper according to claim 4, wherein the pressing means are independently adjustable from each other.

8. The vertical flow-wrapper according to claim 1, wherein the vertical flow-wrapper comprises a pair of rollers, downstream from the sealing means, whose axis of rotation are provided parallel to the transportation plane of the two opposing ends of the formed film and not perpendicular to the transport direction.

9. The vertical flow-wrapper according to claim 8, wherein at least one roller of the pair of rollers is driven, or is driven by a motor.

10. The vertical flow-wrapper according to claim 8, wherein at least one of the pair or rollers comprises a cylindrical roller and a convex surface.

11. The vertical flow-wrapper according to claim 3, wherein the seal jaw for the longitudinal seal and/or the seal jaw for the reclosing means sealing means comprises a ceramic strip.

12. The vertical flow-wrapper according to claim 3, wherein the seal jaw for the longitudinal seal and/or the seal jaw for the reclosing means sealing means comprises air ejection means.

13. The vertical flow-wrapper according to claim 1, wherein the vertical flow-wrapper comprises a device for applying a hole into the film.

14. A method to produce a closable bag, the method comprising: forming a plane film into a tube, applying a longitudinal seal, with sealing means comprising upstream guiding means to the tube, applying a lower cross seal to the tube to form a bag, filling the bag with a packaging item, applying an upper cross seal to the bag, wherein the film is guided by two rollers whose axis of rotation are provided parallel to a transportation plane of two opposing ends of the tube and not perpendicular to the tube.

15. The method according to claim 14, wherein prior and/or after the applying the longitudinal seal step, the opposing ends of the tube are stretched in a direction perpendicular to the transport direction of the tube by two rollers whose axis of rotation are provided parallel to the transportation plane of the two opposing ends of the tube and not perpendicular to the transport direction.

16. The method according to claim 14, wherein an angle of the axis of rotation is adjustable.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] FIG. 1 shows schematically the vertical flow-wrapper according to the invention.

[0048] FIG. 2 shows details of a bag that can be produced with the inventive vertical flow-wrapper or the inventive method.

[0049] FIGS. 3-5 show details of the sealing means.

[0050] FIGS. 6A and 6B show details of the guiding rollers 19 and/or the stretch rollers 28.

[0051] FIG. 7 shows the Eurohole unit wherein the left excentre is in the 9 o'clock position.

[0052] FIG. 8 shows the Eurohole unit wherein the left excentre is in the 12 o'clock position.

[0053] FIG. 9 shows the Eurohole unit wherein the left excentre is in the 3 o'clock position.

[0054] FIG. 10 shows the Eurohole unit wherein the left excentre is in the 6 o'clock position.

[0055] FIG. 11 shows the Eurohole unit in the middle of the cutting position with uncut and cut bags.

[0056] FIG. 12 shows the Eurohole cutting knife with pneumatic cylinder.

DETAILED DESCRIPTION

[0057] In FIG. 1, the vertical flow-wrapper 1 according to the invention is schematically shown and according to FIG. 1, the inventive method is described. A vertical flow wrapper is a packaging machine, which forms a plane film/film (in the following film) web into a film tube, which is transported continuously or intermittently along a form-fill tube 2. Two ends of this film tube are sealed together by a longitudinal sealing means 5. Subsequently, the packaging item is filled into the film tube and a cross-seal 10 is applied to the film tube to close the package. Simultaneously or after applying the cross-seal, the finalized packages are cut off the film tube. The vertical flow wrapper comprises a frame/housing 8, at which a form shoulder 3, a form-fill tube 4, and longitudinal sealing means 5 and cross-sealing means 6 are provided. Furthermore, the inventive vertical flow wrapper can comprise means to attach re-closure means for every bag, for example a zipper, to the film, the re-closure means for each bag are provided parallel to the transport direction of the film and/or parallel to the longitudinal seal 11. The attachment, for example sealing, of the re-closure means to the film is preferably provided at least partially simultaneously to the provision of the longitudinal sealing. The vertical flow-wrapper may comprise gusset-forming means to form the bottom and/or the top of each bag.

[0058] A web of a film 4, especially a weldable plastic film 4, is supplied from a reel, which supplies the plane film continuously or intermittently to a form shoulder 3, which shapes the film web into a rather tubular form around a form-fill tube 2. In the context of the present invention, a “tubular form” of the bags or of the film means any cross-sectional form including a circular form or another form, and especially a rectangular or generally a polygonal form.

[0059] Longitudinal sealing means 5, which are provided downstream from the form shoulder, seal the edges to the film tube together. After sealing, the bottom of the bag 7 can be formed by a special bottom forming means, for example gusset-forming means. Finally, cross seals, extending preferably perpendicularly to the direction of flow of the film, are applied, especially by means of cross-sealing means 6. These cross sealing means 6 apply to the bag 7 not only a cross-seal closing the top of the bag 2, but these cross-sealing means 6 advantageously also provide, preferably simultaneously a cross-seal defining the bottom of the subsequent, upstream bag 2. The bags 2 produced are separated from one another by a cutting means, which are preferably incorporated into the cross-sealing means 6. Between the application of the bottom- and top-cross-seal of each bag, the bag is filled with the product, preferably an edible product. Parallel, at least partially regarding time and in terms of direction to the longitudinal seal, re-closure means for every bag, for example a zipper, is attached to the film. The vertical flow-wrapper may comprise gusset-forming means to form the bottom and/or the top of each bag.

[0060] FIG. 2 shows an example of a bag 7, which can be produced by the inventive flow-wrapper and/or according to the inventive method. Arrow 13 depicts the transport direction of the film. The inventive bag 7 comprises two cross seals 10, which are provided transversely to the transport direction 13 of the film. Parallel to the transport direction of the film and at the opposite end of the bottom 18 of the bag 7, a longitudinal seal 11 is provided. Adjacent to the longitudinal seal, a re-closure means 12, here a zipper, is provided, which allows to re-close the bag after the longitudinal seal has been removed and/or opened. The bag 7 may comprise a gusset at its bottom 18.

[0061] FIGS. 3-5 show details of the sealing means 5 which provide the longitudinal seal and sealing means 24 which seal the re-closing means to the film 4. The means 5, 24 are provided in parallel and each comprise a seal jaw 14, 15, which heat the film and/or the re-closing means. Each sealing comprises two segments through which the film and/or the reclosing means pass. Downstream from the sealing jaws 14, 15, pressing means 16, 17 are provided to press the film ends and/or the film ends and the reclosing means together so that they form a material bond. As can be particularly seen from FIG. 4, the pressing means 17 for the longitudinal seal is provided as a pair of rollers, wherein one roller is provided on one side of the two film ends, respectively. The axis of rotation of the rollers is perpendicular to the transportation direction 13 of the film, which passes through the pair of rollers. The pressing force is preferably adjustable. The pressing means 16 for the reclosing means is preferably provided as a pair of two rollers 16, which are spaced apart, so that the male part of the reclosing means 12 fits in between the two rollers on one axis. The axis of rotation of the rollers 17 is perpendicular to the transportation direction 13 of the film, which passes together with the re-closing means through the pair of rollers 16. The pressing force is preferably adjustable. As can be particularly seen from FIG. 3, upstream from the sealing means for the longitudinal seal, guiding means 19 for the two ends of the film which are sealed together, is provided. The guiding means 19 are here a pair of rollers, one roller being provided on one side of the two ends of the film, whose transport direction is indicated by arrow 21. Each surface of each of the rollers is in touch with the surface of one end of the film. The axis of rotation of each roller is not perpendicular to the transport direction 21 of the film. This stretches the film perpendicular to the transportation direction 21, as indicated by arrow 27 in FIG. 2. As can be seen from FIG. 5, the angle and which the rollers 19 are provided can be adjusted, for example by rotating them around axis 22. This influences the stretching of the film and/or the slip of the film relative to rollers 19. The slip can also, separately or additionally, be influenced by the normal force that the rollers 19 apply to the film. Upstream from the re-closing means sealing means 24 preferably no guiding means is provided.

[0062] The gap between the two parts of each sealing means 5, 24 can be adjusted, preferably automatically by means 20. They can move the sealing means 5, 24 together from a remote position to an operation position. Furthermore, the gap between the two jaws of the sealing means 5 and the sealing means 24 can be adjusted individually. This is preferably done manually.

[0063] Referring to FIG. 3, downstream from the sealing means 5, 24, preferably stretching means 28 are provided. The stretching means 28 are here a pair of rollers, one roller being provided on one side of the two ends of the film, whose transport direction is indicated by arrow 21. Each surface of each of the rollers is in touch with the surface of one end of the film. The axis of rotation of each roller is not perpendicular to the transport direction 21 of the film. This stretches the film perpendicular to the transportation direction 21, as indicated by arrow 27 in FIG. 2. Preferably, one or both of the rollers are driven, preferably by motor. The rollers 28 are not perpendicular to the transportation direction, but provided at an angle, which can preferably be adjusted, for example by rotating them around an axis. This influences the stretching of the film and/or the slip of the film relative to rollers 28. The slip can also be influenced by the normal force that the rollers 28 apply to the film.

[0064] FIGS. 6A and 6B show details of the guiding rollers 19. The same applies to the stretching rollers 28. The rollers 19 are provided on each side of one end 26 of the film 4 whose transport direction is indicated by arrow 13. The surface of each roller touches the surface of one end 26 of the film. The axis of rotation 25 of the rollers 19 are not perpendicular to the transport direction 13 of the film. They are provided at an angle α which is ≠90°.

[0065] FIGS. 7-12 depict a device 29 for applying a eurohole or the like (in the following “eurohole”) to a package, preferably a bag, more preferably a bag produced by a vertical flow-wrapper. The device 29 is provided at the vertical flow wrapper, preferably downstream from the longitudinal sealing means 5. The device applies the eurohole while the film is moving.

[0066] The device comprises a motor, which rotates one of the two sprockets 31, which counterrotate as depicted by the arrows with the reference signs X, Y. Connected to each sprocket is an eccentric 32. The skilled person understands that different means than sprockets can be used as counterrotating means. The eccentrics can be connected via connection means 33, here a rod. The rod 33 can be fixedly connected to one eccentric and guided in a recess of the other eccentric, as a floating bearing. At least one eccentric comprises a punch or a knife 34 to provide the eurohole in the film of a bag. The opposite eccentric may comprise an anvil and/or a counter-knife for the punch/knife 34.

[0067] The punch/knife, the anvil/counter-knife are preferably kept in the same orientation, preferably parallel to each other, at least while the cutting process takes place. The punch/knife and/or the counter-knive/anvil can move in a direction with a perpendicular component to the direction of movement 13 of the film tube 4 or bag 7.

[0068] The following describes an example of the possible movement of the two eccentrics 32:

[0069] When the left eccentrics is in a position between 12 o'clock and 3 o'clock the right eccentrics will be in a position between 12 o'clock and 9 o'clock and the punch/knife 34 and the counter-knife/anvil will cut the film to create a eurohole. The force for the cutting can be provided with a pneumatic cylinder as shown in FIG. 12. The force can also be provided with a spring or an actuator.

[0070] The motor 30 is preferable a servomotor but also other motors or a mechanical connection to the main machine can be used.

[0071] The eurohole is preferably provided into the longitudinal seal 11 of the bag. The film 4 is moving while the eurohole is punched.

[0072] The bag may comprise reclosing means 5.

LIST OF REFERENCE SIGNS

[0073] 1 vertical flow-wrapper [0074] 2 form-fill tube [0075] 3 form shoulder [0076] 4 film [0077] 5 longitudinal-sealing means [0078] 6 cross-sealing- and/or cutting means [0079] 7 package [0080] 8 frame/housing [0081] 9 reel [0082] 10 cross seal [0083] 11 longitudinal seal [0084] 12 reclosing means, zipper [0085] 13 transport direction of the film and/or package [0086] 14 seal jaw longitudinal seal [0087] 15 seal jaw reclosing means, seal jaw zipper [0088] 16 pressing means for sealing the reclosing means [0089] 17 pressing means for providing the longitudinal seal [0090] 18 bottom [0091] 19 upstream guiding means, guiding rollers [0092] 20 displacement drive, linear drive [0093] 21 transport direction of the film [0094] 22 angle adjustment axis [0095] 23 base, base plate [0096] 24 reclosing means sealing means [0097] 25 axis of rotation of the roller 19 [0098] 26 transportation plane of the opposite ends of film 4 [0099] 27 transversal direction [0100] 28 stretch rollers, adjustable stretch rollers [0101] 29 Device for applying a eurohole [0102] 30 motor [0103] 31 sprocket [0104] 32 eccentric [0105] 33 connection means between the eccentrics [0106] 34 knife [0107] 35 eurohole [0108] X, Y rotation direction