Patent Application
20240359900
This invention relates to the manufacture, structure and use of resealable bags that can be filled with material and equipped with outlets for dispensing the contents of the bag.
Resealable bags are commonly used for food storage, transportation of material, and display of material to consumers, although the present invention relates to any type of granular or liquid material. The manufacturing process for prefilled resealable bags is a multi-step process, commonly referred to as form-fill-seal. Machines such as vertical form-fill-seal (VFFS) machines are commonly used, though inclined or horizontal machines may also be appropriate. In other instances, bags can be partially formed and provided empty to material suppliers that can perform the filling and final sealing steps.
Polymer resin or polyethylene (such as low density polyethylene or LDPE) is a common film material used in creating resealable bags, but other materials can be chosen depending on the intended use of the bag. Thin, light, strong and flexible films (or webs) are preferred. The specific type of film used for a resealable bag depends on the intended end use of the bag and the properties required of the film. For example, a resealable bag intended for food packaging may require a film that is food-safe and has good barrier properties to prevent oxygen and moisture from entering or leaving the bag, while a resealable bag for other purposes such as driveway salt may require a film that is more durable and resistant to tearing.
The film to make resealable bags can be printed if desired, for instance with advertising, ingredients, instructions for use etc., and wound onto rolls for web processing. A continuous roll of the film is unwound from a film roll holder and fed into a forming section of the bag forming machine. In the forming section, a folded web of film (in the use of a single web system) or flat webs of film (in the use of a dual web system) are brought together and bonded to create the form of the nascent bag. Side seals, or fin seals, are created on two sides of the bag, and top and bottom seals can be created as well depending on the design and use of the bags. Different bag structures may be created, such as pillow bags, gusseted bags, and quad seal bags, as is well known in the art.
Stand up pouches (SUPs) are increasingly popular, and they are designed to stand upright on surfaces such as a cupboard or in a refrigerator, making it easier for consumers to handle and store. The stand-up feature is achieved by adding a gusset to the bottom of the pouch, which allows the pouch to expand and stand upright when it is filled, being self-supporting on its bottom surface.
If a resealable bag is desired, resealable zippers are coupled to one or more of the interior surfaces of the nascent bag. This is typically done using a machine that introduces the zipper between layers the film and seals the zipper in place using heat and pressure or ultrasonics.
The bag then can be prefilled with material in a variety of ways depending on the type of product and the desired level of automation. For instance, gravity filling may be used, in which the material is loaded into a hopper above the bag and allowed to flow by gravity into the bag below. The bag may held open by a filling spout or by vacuum suction cups as disclosed in U.S. Pat. No. 3,688,471 during this process. In an auger filling method, a rotating screw (auger) moves the material from a hopper and into the bag. The speed of the auger can be controlled to adjust the amount of material being dispensed. In a vibratory filling, method, the material is loaded into a vibrating tray that causes it to settle evenly into the bag. This method is often used for small or lightweight materials. Vacuum filling and pump filling techniques can also be used. In most instances, the prefilled material is metered, and material ingress to a bag is discontinued once a predetermined amount of material is contained in the bag.
After the zipper has been applied and the bag has been filled with product, the film may be cut into the desired size and shape using a cutting and/or sealing machine, and the bag may be further sealed along a selected edge used for filling. The film may sealed on two, three or four sides. If the zipper is within the seals of the bag structure, a user can remove one side of the bag (e.g., a top side), and then the consumer can access the contents of the bag through the resealable zipper exposed by removal of the chosen side of the bag. A removable sealed header can also be provided to create a temporary seal on the fourth side of the bag—near where the zipper exists—for the consumer to remove prior to use.
There are generally two types of closure mechanisms, a press-to-close system and a zip slider. In both, mating protrusions are coupled together on opposing sides of the closure mechanism on opposing internal sides of the bag to keep the bag sealed, and then the mating protrusions are decoupled to open the bag when desired. Examples of mating protrusions include a hook (generally referred to as male) and a hook track (generally referred to as female).
Filled bags are then transported to a point of sale, where they are displayed for purchase and use by consumers.
A resealable bag is produced with a series of apertures spanning first and second sidewalls of the bag, allowing egress of material from the bag. The apertures are integrated with a closure mechanism, preferably on the same web introduced into the resealable bag manufacturing process.
The material contained in and dispensed from the bag may be any material that is desired to be controllably dispensed from the bag, such as fluids or granular material including spices, seasonings, food products, fertilizer, seed, powders, salt, etc. Different sizes of pouches and different aperture sizes and configurations can be provided to accommodate preferred storage and dispensing of the selected material.
In one aspect of the invention, a closure mechanism for a bag structure for carrying at least one granule is disclosed, the closure mechanism comprising preferably a male and a female mating structure carried on a top side of a strip, and a plurality of discontinuous apertures formed in a middle section of the strip that occupies the mouth of a reclosable bag in use. The apertures are sized to controllably dispense the contents of the bag.
A larger aperture can be formed at one side of the bag mouth structure, with finer apertures formed at the other side of the mouth bag, to provide the user a choice between rapid and slower dispensing rates.
Advantages of the present invention over the prior art are reduced cost and storage space requirements. If spice jars are used to contain and dispense spices, it is estimated that it would take an entire truck to transport 30,000 spice jars, whereas 50,000 bags of the present invention could fit on a single pallet. Because spice jars are also considerably more expensive than bags of the present invention, the result is significant cost and space savings.
Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
Referring now to
The resealable bag 10 is designed to hold material 36 in the bag interior 44. The present invention is particularly suited to dispense granular material, but other types of flowable materials may be held in the bag interior 44 and dispensed therefrom.
In a preferred embodiment, either two plies of material such as low density polyethylene (LDPE) film or a compostable web, or a single ply of those folded about itself, create a first bag wall 46 and a second bag wall 48. Side edges of the bag 10 can be sealed or bonded at side seams 32, joining first bag wall 46 with second bag wall 48. In a preferred embodiment, a gusseted bag 10 is created by providing corner seams 40 and gusset flaps 38. During formation of the bag 10, a gusset fold 42 is formed (see
Referring now to the top of the bag 10, optionally a top seam 34 and/or a sealed header zone 28 can be created by bonding first bag wall 46 with second bag wall 48. A hang hole 30 (or a handle) can be formed through a top portion of bag 10, such as through sealed header zone 28. Tear notches 24 can be provided through or into side seams 32 on one or both sides of bag 10 beneath the sealed header zone 28. A tear score 26 can be provided between tear notches 24 to facilitate partial opening of the bag 10 to expose closure structure 12 of closure strip 14, by which bag 10 may be fully opened.
Closure strip 14 may contain several preferred features. A series of ridges 20 may be provided to act as a closure strip finger grip structure 20. Closure structure 12 provides the resealing function of bag 10, preferably using mating elements as described below in reference to
Referring now to
A male structure 50 extends inwardly from closure strip 14 adjacent to first bag wall 46, and to seal bag 10, the male structure 50 can be placed within female structure 52 extending from closure strip 14 adjacent second bag wall 48. Optionally, a zipper shield 54 can be provided beneath the male and female zipper structures 50 and 52 to minimize the contents of bag 10 from being exposed to, and possibly interfering with closure of the male and female zipper structures 50 and 52 if granular material becomes lodged in or to mating portions 50 and 52.
An unbonded region 64 of closure strip 14 extends between the bag first wall 46 and the second bag wall 48 between opposing bonded regions 58 on first bag wall 46 and second bag wall 48. Within this unbonded region 64 of closure strip 14, a closure aperture 16 or preferably a series of apertures 16 are provided.
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In other embodiments, closure structure 14 and its constituent elements can be placed at a bottom or a side of bag 10 (not shown).
To form bag 10 (not shown) a first film or material web is provided (or two webs are provided in parallel) to form first and second walls 46 and 48. A bottom gusset is formed by folding gusset fold 42, and bonding a plurality of corner seams 40. Separately, a continuous closure strip 14 and the elements of
In in one embodiment, only one of bag walls 46 and 48 are bonded to closure strip 14 on an interior surface of the selected bag wall 46 of 48. At this point, bags 10 can be shipped out to a customer for filling and final sealing. Material 36 can be introduced into bag interior 44 through bag walls 46 and 48, through and between closure strip 14 and the unbonded wall 46 or 48. Next, tear notch 24 and tear score 26 can be formed on bag 10. Header zone 28 and top seam 34 can also be created by bonding walls 46 and 48, and hang hole or handle 30 can be formed in header zone 28.
In another embodiment, material 36 can be introduced into bag interior 44 prior to introducing closure strip 14 into the process, or prior to bonding closure strip 14 to one or both bag walls 46 and 48. Next, closure strip 14 can be bonded to bag walls 46 and 48, and tear notch 24 and tear score 26 can be formed on bag 10. Header zone 28 and top seam 34 can also be created by bonding walls 46 and 48, and hang hole or handle 30 can be formed in header zone 28.
Following these steps, sealed and closed resealable bags 10 containing material 36 are prepared for shipping, display, purchase, and use.
The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
