Reclosable bag

IS 2 227 263 T3

DESCRIPTION

Lockable bag.

The invention relates to improved bag making, bag products and a preformed material useful in bag making.

It has been known to provide packaging machines with a packaging film to which a snap-on rib and slit closure is pre-applied at a strategically located position. See, for example, US Patent 6,079,878 to Yeager. A film of this type with previously applied rib and slit closures has been introduced into a vertical forming and filling machine to form a bag and fill it with the contents simultaneously, the bag being capable of being opened in the previously applied closure.

Such a product has its limitations. For example, in zipper products (snap rib and slit), to maintain the alignment and integrity of the closure once closed, it is necessary that the ends of such a closure be closed and permanently sealed to provide a starting point for closing. Other limitations related to manufacture and use are also known.

In WO 00/27721 A1, a composite contact closure consisting of a strap of ties and an attachable strap with ties is also described, which can be applied to, for example, a closable bag, in which the substrate of The bag has to be folded along a line between the tie and zipper strip to close the bag.

Summary

According to the invention, a bag has a body with opposite faces having lateral edges and defining an interior, the bag comprising a closable closure strip attached to one of the faces of the bag and extending around one of the edges of the bag to form a closable bag closure to access the interior of the bag, whereby the closure extends from a front face of the bag, around a side edge of the bag, to a rear face of the bag to form a spout for pouring the contents of the bag from a bag opening at the edge of the bag.

In some embodiments, the closure strip is attached to an internal surface of the bag, and the body of the bag may have a frangible tear line to access the closure strip. In some cases, the closure strip includes a loop component with a hook-engageable loop strip, and a corresponding hook component having a hook strip, which may be integrally molded along one edge of the hook component. .

In some configurations, the closure strip comprises two components in contact, both attached to an inner surface of one face of the bag.

In some cases, the body of the bag comprises a film, the closure strip being welded to the film.

In some embodiments, the closure strip extends across the entire front face of the bag and around opposite edges of the bag to form a hinge.

In some embodiments, the ends of the closure are loose from each other. According to the invention, a method of making a closable bag is provided. The bag has a body with opposite faces having side edges and defining an interior. The method includes shaping the bag in a bag making machine from a web of film having pre-applied closure strips arranged to extend around one of the bag edges to form a closable bag closure for access the interior of the bag, whereby the closure extends from a front face of the bag, around a side edge of the bag, to a rear face of the bag to form a spout for pouring the contents of the bag from a bag opening at the edge of the bag.

In some embodiments, the closure strip is attached to an internal surface of the bag, and the body of the bag may have a frangible tear line to access the closure strip. In some cases, the hooks are integrally molded along one edge of the hook component. In some configurations, the closure strip comprises two components in contact, both of which are attached to an internal surface of one face of the bag.

In some cases, the body of the bag comprises a film, the closure strip being welded to the film.

In some embodiments, the closure strip extends across the entire front face of the bag and around opposite edges of the bag to form a hinge.

In some embodiments, the ends of the closure are loose from each other.

In accordance with certain aspects of the invention, a hook and loop closure is pre-applied to a packaging film. The closure involves a hook strap and a loop component, which are coupled by hook and loop closure. In some cases, each component has an associated rim or edge portion that is surface welded to the bag film. In other cases, the components can be attached directly behind the closure elements, such as hooks or loops.

In some cases, the hook component and the loop component are separate pieces, but in contact in their pre-application condition. In other cases, the two are formed as a unit, in which case a connecting part between the two pieces of the closure can provide the "factory closure" that is broken to open the bag initially.

A number of advantages are obtained with preforms of this type.

The closure does not need to be spaced from the edges of the bag being formed.

The tolerances for the machine and for the location of the closure preform and film in the machine are relatively relaxed. Hook and loop alignment is also less critical than with rib and slit closures. For example, variations in positioning of up to 1/8 inch (3.2 millimeters) or more are generally tolerable with the hook and loop closure, while maintaining acceptable closure performance.

Another aspect of the invention relates to bags in which the bag closure and opening extend across the entire width of the bag.

The closure does not need to be laminated on only one side of a bag, spaced from the edges, eg

ES 2 227 263 T3 ro can extend completely up to one edge or even around an edge to the opposite face, for example to form a pouring spout or a hinged lid. In addition, hook and loop fasteners can perform their role in a corner or cross fold, whereas zipper structures that are severely bent or folded tend to cause zipper elements to distort or separate, and can cause leakage or separation at the crease or fold.

Another aspect of the invention relates to bags that can initially be filled completely or with very little headroom, and that can be easily closed by the hook and loop closure while the bag remains filled so that it overhangs the closure.

In the hook and loop closure shown, the ends of the closure may be loose from each other. This provides the ability to have a larger bag opening than in the case of a rib and slit closure, but if desired, the ends of the closure can be sealed or welded to the bag film, for example, to avoid end leakage. The alignment required to close the hook and loop closure is substantially less critical than for the rib and slit snap closure, and is therefore an easier closure to activate or deactivate (open and close) with a full bag or with a very large opening.

Other features and advantages of the invention will be understood from the following description of preferred embodiments.

Brief description of the drawings

Figure 1 shows a vertical shaped and filled bag that is not protected by the invention, with its front face facing the observer.

Figure 2 is a cross-sectional view, taken along line 2-2 in Figure 1.

Figure 3 shows a similar bag according to the invention, with the closure located on the front face and around the side of the bag.

Figure 4 is a cross-sectional view, taken along line 4-4 in Figure 3.

Figure 5 is a cross-sectional view, taken along line 5-5 in Figure 4.

Figure 6 is a view similar to Figure 4, but of a "flip top" bag, in which the closure 12 extends over one face, and around the face of the bag on both sides of the bag. .

Figure 7 shows the bag of Figure 3, opened to pour its contents through the open closure.

Figure 8 shows a bag film strip with pre-applied closures to form bags.

Description of illustrated embodiments

Figure 1 shows a vertical shaped and filled bag 10 that is not protected by the invention, with its front face facing the observer. Welded to the inside of the front face 30 of the bag is a hook and loop closure 12, shown in dashed lines. Along the closure, the bag film that forms the front face 30 of the bag closure is provided with a frangible line 14, tear cord, perforation, or other feature to form an opening in the closure, through the film from the bag. For perishable products, the bag film preferably forms a primary seal to maintain the freshness of the bag's contents.

Figure 2 shows the closure 12 in side view. The upper half of the closure is the loop component 16 with a strip of hook-engageable loops 32 along its bottom edge, and is welded to the inner surface 34 of the front face 30 of the bag along its edge. higher. In a somewhat lower position of the bag, a corresponding hook component 18 has a strip of hooks 36 integrally molded along its upper edge, in contact with loops 32 of the upper half of the closure. This lower component is also welded to the inner surface of the front face of the bag. In this way, the front face 30 of the bag carries both halves of the closure 12, joined to the film of the bag in weld lines 19, and in contact by the hook and loop coupling. The closure halves may also be welded to the front face bag film at their ends, if desired.

As shown in Figures 1 and 2, the primary or factory closure is the bag film itself. To open, the end user makes a cut in the film to access the internal all-purpose closure 12, or an element such as a frangible line 14 is provided in the film so that a tab can be opened through the film. For example, a pressure-sensitive self-adhesive strip may be provided to form a releasable tab (not shown) that can be lifted to access the interior of the bag. The inside of the bag is opened in this way, advantageously without tools such as scissors or knives. The contents can be removed from the bag, and then pressure can be exerted on the closure to close the bag for storage in the pantry. The hook and loop closure 12 can be closed with a relatively low contact force, and it can conform to debris trapped in the closure. Also, for applications where the closure is on the face 30 of a bag rather than along the top edge 38, for example, the hook and loop closure can be loosely closed without using excess pressure for the closure that it could damage the underlying product inside the bag. Potato chip bags, for example, may be provided with such a face closure.

Figure 3 shows a bag 20 according to the invention, of the same construction as the bag 10 of Figure 1, except that instead of being extended on the center line of the front face 30 of the vertical shaped and filled bag, the closure 12 is seen to extend around the side 40 of the bag. Figure 4 shows a sectional view through the bag, the longitudinal film closure 22 being located towards the rear. The front face 30 is the clean face of the bag, or the face without the longitudinal closure 22.

Figure 5 is similar to Figure 2 in that the top of the closure 12 is the loop section 16 welded to the inner surface of the film 24, and the hook section 18 is directly below it, welded to the film surface. 24. While the closure is welded to the same topologically continuous film surface, the closure 12 extends from the front face of the bag, around one side edge of the bag, to the other face. In other words, the closure 12 is welded to the rear face 44 of the bag as well as the front face 30.

Figure 6 shows, schematically, the

ES 2 227 263 T3 closure 12 that extends over the entire front face 30 of the bag, and around both edges 40 and 42 to the rear face 44 of the bag. With the substance of the bag walls being sufficiently rigid, the portion of the bag between the ends 46 of the closure defines a hinge around which the entire upper portion of the bag or package can rotate, such as in a "lid box. collapsible ”, to provide full access to the interior 48 of the bag (or box). Obviously, this type of construction is useful for high-strength packaging, formed for example of thick paper or bag or box composite materials, as well as thick film.

Thus, the closure can extend over the entire front face 30 of the bag, and even around the edges 40, 42 of the bag. The closure could be positioned to provide a hinge line extending over the longitudinal seam line 22 produced by the forming and filling machine vertically, to allow full opening of the bag, as shown in Figure 6. Also, if the free height of the bag is very low (defining "free height" as the free volume above the product but inside the bag), the contact closure of the hook and loop closure type can still be opened, the product it can come out of the bag and then only a very gentle actuation force is needed to close the closure 12, pressing against the product from the outside. This is different from a zip closure (rib and rib closure), in which an unoccupied volume is required in the closure to allow the user to place their fingers both behind and in front of the closure to snap it closed, to coupling the male component or rib into the female component or slit of the closure.

It turns out that the hook and loop closure 12 can tolerate bent configurations, such as those illustrated in Figures 3-6, with the closure being subjected to a shear load throughout its extension when the product within the bag 20 presses against the closing. That is, the pressure of the contents does not tend to separate the upper part from the lower part of the bag by pressure. In this configuration, the hook and loop closure 12 is in its highest strength mode. In addition, forming the closure 12 in an arc or other shape that extends out of the plane of the closure, as shown, can add flexural strength or structural rigidity of the closure 12 to withstand concentrated spacing loads.

As in the embodiment of Figure 1, the primary or commercially available closure in this embodiment is the bag film between the two closure components. However, as is also the case with Figure 1, primary closure can also be achieved by an integral hook and loop closure unit such as that described in patent publication WO 00/27721, published May 18, 2000. In such a case, when the hook and loop closure unit 12 is previously applied to the film strip, prior to passing it through the vertically forming and filling machine, a cut-shaped opening is formed in the film itself ( for example, at 14, while the closure 12 is being welded to the film of the bag). In this case, the closure may be on the outer surface of the bag.

A complementary closure, such as a peel closure, a tear closure, a tear cord closure (not shown) may also be provided, either on the hook and loop closure unit or on the bag itself.

Figure 7 shows that the structure of Figure 3 allows closure 12 to be opened like a pour spout to allow the user to pour the contents from a bag opening 26 at the side edge of the bag. Unlike zipper products, if the hook and loop closure is folded or folded in any way on its face, or perpendicular to the longitudinal direction of the closure, the closure effect of the closure is maintained. In contrast, zipper guides (eg, slit-coupled ribs) tend to assume a permanent posture or deformation when bent from the front to the side, or the other way around, causing the zipper to open or close. . If it is opened, the guide is not clamped between the sides of the slit, and the closure is expired. Of course, with zipper closures, any opening along the zipper seriously reduces the zipper's ability to withstand separation from spreading.

Figure 8 shows a film strip 28 of the bag with closures 12 already welded in place, transversely to the longitudinal axis of the film, and ready to be unwound to enter a bag making machine, to either make the bag 10 of Figure 1 or the bag 20 of Figure 3, depending on the length of the closure 12 and where the film is transversely cut and joined to form the upper and lower closures.

Other bag and closure constructions and bag-forming methods to which the aforementioned features apply are described in our US Patent No. 6,202,260, and in our provisional US patent applications. .UU. Nos. 60 / 159,489, 60 / 228,819, and 60 / 231,377 (filed October 14, 1999, April 16, 1999, and September 6, 2000, respectively), the full descriptions of which are incorporated herein by reference as if were fully exposed.

Numerous embodiments of the invention have been described. However, it will be understood that various modifications can be made without departing from the spirit and scope of the invention. For example, it is to be noted that many features described herein can be applied to the closure bonding step during bag making, and also prior to closure application. Accordingly, other embodiments are within the scope of the following claims.