Method of attaching fitments in a vertical form fill and seal machine

Abstract: A vertical form fill and seal (VFFS) machine is configured to place a fitment, such as a spout (102), on the longitudinal fin seal (104) of a container (200, Fig. 4). The fitment (102) dispatched from a vibratory bowl (22) via an adjustable track (24). The fitment is then secured to edges of the film (100) by longitudinal sealing bars (26) and the edges of the film are likewise secured to each other by the longitudinal sealing bars (26) thereby forming a longitudinal fin seal (104). Depressions are machined in the machine direction center of the sealing bars (26) in order to accommodate the shape of the fitment (102). The film is drawn over an oversized collar (18) and an undersized tube (12) and bars (40, 42, Fig. 3) so as to create excess film in order to form gussets providing a stand-alone capability.

Description: This invention pertains to a method for attaching a fitment to a package being assembled in a vertical form fill and seal machine by feeding the fitments, such as a spout for a pouch, from a vibratory bowl and using longitudinal sealing bars to secure the fitment to the edges of the film and further to secure the edges of the film to each other to form a longitudinal fin seal. Vertical form fill and seal (VFFS) machines are known in the prior art for forming a container, filling the container with foodstuffs or similar items, and sealing the container. These machines are advantageous in that all three steps are performed in rapid succession in substantially the same location. However, heretofore, while the advantages of bag-type or pouch containers with a fitment or spout, particularly when the containers are filled with a liquid or paste, have been recognized in references such as US-A-5,606,844, the vertical form fill and seal machines have not been adapted to place a fitment, such as a spout, on the longitudinal fin seal of the container being formed, filled and sealed. Similarly, while the use of a horizontal flow, vertical fill machine to put fitments on the bottom folded edge of the resulting pouch has been disclosed in US-A-4,512,136, this has not resulted in a pouch with the fitment fitted along the longitudinal fin seal of the pouch, particularly a free-standing pouch manufactured by a vertical form fill and seal apparatus. Other prior art appears to contemplate sealing fitments to a package on a form fill and seal machine. However, this art appears to be directed to a sealing of a flanged fitment to either the inside wall of the film or the outside wall of the film and puncturing the film to activate the fitment. This art does not disclose the use of a vertical form fill and seal machine to secure to the fitment to the longitudinal fin seal of the pouch. WO 97/15497 discloses a method in accordance with the preamble of claim 1 and a packaging machine for forming free standing flexible packages with a fitment included on one edge. Prior art in this general field further includes US-A-5,862,652 and US-A-3,376,687. Accordingly, the invention consists in a method of forming a sealed container enclosing a product to be dispensed through a fitment secured to the sealed container, comprising the steps of: wrapping a film into a generally cylindrical shape; dispatching a fitment to a portion between longitudinal edges of the film; securing the fitment to the longitudinal edges of the film; securing the longitudinal edges of the film to one another thereby forming a longitudinal fin seal containing the fitment; forming a first transverse seal; providing contents to the container; and forming a second transverse seal thereby sealing the container; characterised in that the steps of securing the fitment and securing the longitudinal edges of the film are performed by a common set of longitudinal sealing bars provided with depressions to receive the fitment, in that said step of wrapping the film in a cylindrical shape is performed by drawing the film over an oversized collar and around an undersized tube, the edges of the film extending through a gap in the oversized collar while being drawn around the undersized tube, which creates excess film in the cylindrical shape; and in step of forming a gusset with the excess film using gusset forming means between the collar and the tube thereby causing said container to have a free-standing capability. Preferably, the method of the invention is carried out on a vertical form fill and seal machine having cross-sealing jaws and longitudinal sealing bars. The longitudinal sealing bars have shaped sealing surfaces at the fin area, with depressions machined in the machine direction center of the longitudinal sealing bars to accommodate the shape of a fitment. Fitments typically have "boat" shaped bosses to facilitate the transition from film to fitment sealing to film to film sealing. The fitments are preferably dispensed from a vibratory bowl assembly onto a track, and down to the center of the sealing bars to match the machined depressions. The sealing bars seal the edges or fins of film around the fitment, and to each other above and below the fitment thereby forming the longitudinal fin seal. Preferably, the vertical position of the longitudinal sealing bars and the fitment delivery track is adjustable during a size changeover time. The film is preferably punched in registration to create an ability to seal the outer layers of the film gussets together at the gusset sealers and/or cross-sealing jaws. Alternatively, the film may be formed with a sealant layer on both sides to facilitate sealing the outside layers to each other. Additionally, the gussets may be sealed below the guiding ribs or transition point. A set of pinching spreaders are positioned below the cross-sealing jaws to pinch or spread the gussets immediately prior to filling, and to create additional space for the product and to move the product away from the cross-sealing jaws thereby improving the cross-seal conditions. Optionally, the longitudinal sealing bars may include more than one set of depressions resulting in multiple film to fitment sealing positions. A particular example in this invention will now be described with reference to the accompanying drawings; in which:- Figure 1 is a front elevation of the vertical form fill and seal machine; Figure 2 is a side elevation of the vertical form fill and seal machine; Figure 3 is a cross-sectional view of the tube and collar of the vertical form fill and seal machine, illustrating how the stand-up feature of the pouch is implemented on the film; Figure 4 is a perspective view of a typical resulting package with a fitment; and, Figure 5 is a perspective view of a typical fitment used with the present invention. Referring now to the drawings an oversized cylindrical collar 12 is formed concentrically about undersized tube 14. As is known with form fill and seal machines, the contents of the resulting pouch is fed through bottom opening 16 of tube 14 into the pouch which is formed by the film 100 which passes over collar 12 and tube 14 as guided by obliquely oriented shoulder 18 (also see Figures 2 and 3). Cross-sealing jaws 20 are formed horizontally below bottom opening 16 of tube 14 in order to cut the film 100 into separate bags or pouches and to form the transverse seal and hence the package which secures the contents during the initial filling. Cross-sealing jaws 20 furthermore seal the previously filled package during the same step. Vibratory bowl 22 is situated so tube 14 dispatches fitments 102 via telescoping track 24 to longitudinal sealing bars 26 which secure the edges of the film 100 to fitment 102 (see Figures 4 and 5 for the detail of a typical fitment 102, which typically includes "boat" shaped bosses 110, a threaded spout 112, and a threaded cap 114). The longitudinal sealing bars 26 further join the edges of the film 100 to each other above and below fitment 102 thereby forming longitudinal fin seal 104 of the film 100. The position of the longitudinal sealing bars 26 and the telescoping track 24 is adjustable so as to accommodate several different bag widths. These positions would typically be changed at size changeover time. As shown in Figure 2, hole punching gusset 28 punches the film 100 in registration to create an ability to seal the outer layers of film gussets together at the gusset sealing jaws 30 and/or cross-sealing jaws 20. Double gusset former 29 is positioned generally below hole punching gusset 28 and 180° from longitudinal sealing bars 26 in order to form the structure shown in Figure 3 wherein outwardly protruding ribs 40 are formed on undersized tube 14 and inwardly protruding ribs 42 are formed on oversized cylindrical collar 12 in order to form a double fold for the stand-up feature. The oversized collar 12 and undersized tube 14 create excess film, which is thereby folded by the double gusset former 29 and thereafter sealed by gusset sealing jaws 30. As shown in Figure 2, gusset or pinching spreaders 32 are positioned to pinch or spread the gussets prior to filling, particularly if a viscous or paste-like substance is being filled, to create additionally space for the product and to move the product away from the cross-sealing jaw 20. Moreover, this improves the cross-seal conditions. A typical resulting package 200 is shown in Figure 4 wherein fitment 102 is sealed within seal 104.

Claims: A method of forming a sealed container (200) enclosing a product to be dispensed through a fitment (102) secured to the sealed container, comprising the steps of: wrapping a film (100) into a generally cylindrical shape; dispatching a fitment (102) to a portion between longitudinal edges of the film (100); securing the fitment (102) to the longitudinal edges of the film (100); securing the longitudinal edges of the film (100) to one another thereby forming a longitudinal fin seal (104) containing the fitment (102); forming a first transverse seal; providing contents to the container (200); and forming a second transverse seal thereby sealing the container (200); characterised in that the steps of securing the fitment (102) and securing the longitudinal edges of the film (100) are performed by a common set of longitudinal sealing bars (26) provided with depressions to receive the fitment (102), in that said step of wrapping the film (100) in a cylindrical shape is performed by drawing the film (100) over an oversized collar (12) and around an undersized tube (14), the edges of the film (100) extending through a gap in the oversized collar (12) while being drawn around the undersized tube (14), which creates excess film in the cylindrical shape; and in the step of forming a gusset with the excess film using gusset forming means between the collar (12) and the tube (14) thereby causing said container to have a free-standing capability. The method according to claim 1, wherein said step of forming said first transverse seal for one container (200) is performed simultaneously with said step of forming a second transverse seal for a previous container. The method according to claim 1 or 2, wherein said steps of forming a first transverse seal and forming a second transverse seal are performed by transverse sealing jaws (20). The method according to any one of the preceding claims, further including the step of using means (32) for spreading portions of the container (200) thereby providing additional room for the product prior to said step of forming a second transverse seal. The method according to any one of the preceding claims, including the step of providing means for varying a position of the longitudinal sealing bars (26). The method according to any one of the preceding claims, wherein said dispatching step is performed by a vibratory bowl (22) and adjustable track (24).

Inventors: MALIN ART, MALIN, ART
Applicants: ILLINOIS TOOL WORKS, ILLINOIS TOOL WORKS INC.
Application year: 2000
Main classification: B65B61
IPC codes: B65B9, B65B61