HK1028007A1 - Liquid plastic film pouch with inner straw - Google Patents

Abstract

A liquid product carrying plastic film pouch (10) having a straw (12) free-floating in the liquid product (11) is described. The liquid product (11) contained within the inner chamber (13) of the pouch occupies from about 60 % to about 90 % of the volume of the inner chamber (13) of the pouch and a portion of air from the remaining volume is evacuated in sufficient quantity to permit the side walls (14, 15) of the pouch to be collapsed against one another when the pouch is grasped by the hand of a user person. By collapsing the side walls (14, 15) together the straw (12) located within the liquid can be grasped and manipulated to puncture the plastic film pouch (1) to extend a portion (12') of the straw (12) exteriorly of the pouch whereby to extract liquid therefrom. The pouch (10) is made of a multilayer resin film having an inner sealant layer (26) formed of a linear low density ethylene-octene copolymer or very low density ethylene copolymer (octene or other copolymers) such that when the straw punctures the film, the inner sealant layer (26) forms a membrane about the straw which exhibits a self-sealing behavior so as to prevent leakage in the punctured region as liquid is extracted from the pouch (10) through the straw (12). The machine and method of fabrication is also disclosed.

Description

Liquid-filled plastic film bag with internal straw

Technical Field

The present invention relates to a sealed plastic film pouch containing a liquid and a free floating straw, wherein air is evacuated from a space within the pouch to facilitate manipulation of the pouch, i.e. squeezing the side walls of the pouch to grasp the straw and penetrate it through the pouch, and further wherein the pouch is formed from a multilayer film having an inner sealing layer which has a self-sealing capability around the straw in the penetration region to provide a seal around the straw.

Technical Field

It is known to form liquid packaging containers from sealed plastic bags, in which a straw-like article or a liquid discharge is held in the bag and floats freely in the liquid contained in the bag. As an example, one such liquid filled bag container is described in U.S. patent 3,730,336 issued on 5/1 of 1973. However, such packaging containers have the disadvantage that it is difficult to manipulate the bag to grasp the straw and to cause the straw to penetrate the bag due to the amount of liquid and trapped air contained in the bag. This manipulation often results in the rupture of the bag. Furthermore, it is also important that if it is desired to freeze the liquid in the package, the bag should be provided with additional added volume, as the additional volume may allow the liquid to expand when frozen.

It is desirable to have a straw with sufficient rigidity, such as a polypropylene straw, so that the straw does not need to be cut with a bevel at one end to puncture the bag, nor does it need to have any means for gripping on the straw to facilitate its movement in the bag, which would also cause other drawbacks to the automatic filling of the bag. It would also be desirable to be able to provide a liquid packaging container that is highly clean and made of a plastic that does not impart a bad taste (sour taste) to the contained liquid, particularly when the liquid needs to be preserved for a long period of time. It is also desirable that the shelf life of such packages be long, so that the package and the liquid it contains can be stored for a long time before use. It would also be desirable to provide a plastic film pouch that forms a seal around a straw when the pouch is penetrated by the straw and that is resistant to impact during handling and shipping.

It is also known to manufacture plastic film liquid-filled bags in which a free-floating straw is contained. Some manufacturing methods form the pouch by folding a sheet of film horizontally and placing a straw in the lower folded portion of the film strip prior to seal formation to produce an open-ended pouch containing a straw and ready for filling with liquid. However, this task becomes particularly difficult when the pouch is manufactured in a vertical manner by means of a vertical forming machine, in particular for the continuous dispensing of liquids, since the straw must be placed in the pouch when the pouch is filled with liquid during the continuous dispensing of the liquid. This presents several problems, one of which is the manner in which the straw is dispensed into the bag being filled in synchronization with the sealing cycle of the bag. Another problem is to ensure that the straw is prevented from protruding into the sealing jaw when an open-ended bag formed from a plastic cylinder is placed into the sealed bag where the open top end is to be sealed to form a sealed bag. Another problem is to enable the straw dispensing mechanism to accommodate bag forming and filling equipment. It is also desirable that during the manufacture of these sealed, liquid-filled bags, a portion of the air is vented from the space formed in the bag that is necessary when the liquid is frozen and expanded.

GB-a-789368 describes a plastic film bag for containing a liquid product. The blister pack has opposed sidewalls that are sealed at the periphery to form a sealed cavity. At least a portion of at least one of the side walls is made of a transparent plastic to allow vision into the interior cavity. A suction tube having a predetermined rigidity is freely accommodated in the inner cavity. A liquid is contained within and occupies a volume of said interior chamber, wherein said straw is capable of being grasped within said liquid and passed through said plastic film pouch such that a portion of the straw extends outside of said pouch to draw liquid from said pouch. This patent does not teach the venting of air to facilitate grasping of the straw.

Summary of The Invention

It is therefore a feature of the present invention to provide a plastic film bag which overcomes the above-mentioned disadvantages of the prior art and meets the above-mentioned needs.

Another feature of the present invention is to provide a sealed plastic film pouch containing a liquid and a straw that floats freely in the liquid, and wherein a predetermined amount of air is evacuated from a space contained within the interior cavity of the pouch.

It is a further feature of the present invention to provide a sealed plastic film pouch containing a liquid and a straw which is free floating in the liquid, and wherein the plastic film is a multilayer film with an inner sealing layer which, in use, has a firm self-sealing capability around the straw in the region of the pouch penetration, thereby providing a seal for the straw.

It is a further feature of the present invention to provide a method for forming a plastic film pouch containing a liquid and a straw which substantially overcomes the above-identified deficiencies of the prior art and meets the above-identified needs.

In accordance with the above features, the present invention provides, in one broad aspect, a plastic film bag for containing a liquid product. The blister pack has opposed sidewalls that are sealed at a periphery to form a sealed cavity. At least a portion of at least one of the side walls is made of a transparent plastic to enable vision into the interior cavity. A straw having a predetermined rigidity is freely placed in the inner cavity. The length of the straw is shorter than the length of the side wall. A liquid is contained in the interior chamber. The straw is free-floating in the liquid and is movable in the liquid across the side wall. The liquid contained in the lumen occupies about 60% to about 90% of the volume of the lumen. The plastic film pouch is characterized in that a sufficient amount of air is displaced from the remaining volume of the interior cavity such that when the side walls are collapsed toward each other, liquid can move within the interior cavity to grasp the straw therein and penetrate the straw through the plastic film pouch such that a portion of the straw extends outside the pouch to draw liquid from the pouch.

Brief description of the drawings

A preferred embodiment of the invention will be explained below by means of the attached drawings, in which:

FIG. 1 is a perspective view showing a plastic film pouch constructed in accordance with the present invention, wherein a liquid and a straw are contained within the interior cavity defined by the sealed pouch;

FIG. 2A is a plan view of the plastic film bag of FIG. 1, wherein the bag is constructed entirely of transparent plastic;

FIG. 2B is a plan view showing a plastic film bag formed by an opaque rear wall and a partially opaque, partially transparent front wall;

FIG. 3 is a perspective view showing how a straw within the plastic film bag punctures a corner of one of the side walls, thereby exposing a portion of the straw for drawing liquid from the bag;

FIG. 4 is a perspective view, in partial section, showing how the side walls of the pouch are collapsed to grasp the straw;

FIG. 5 is an exploded view showing a sealing diaphragm formed by a self-sealing layer inside a film surrounding a straw;

fig. 6 is a cross-sectional view showing the composition of the multilayer resin film.

Detailed description of the preferred embodiments

Referring to the drawings and in particular to fig. 1, there is shown therein a sealed plastic film pouch, generally designated 10, in accordance with the present invention. A liquid product 11 and a free floating straw 12 are contained within the interior cavity 13 of the pouch 10. The plastic film bag has opposed side walls 14 and 15 which are sealed at a peripheral edge 16. The pouch 10 is shown here as being made of a transparent material so that the free floating straw 12 and the liquid product can be seen. Of course, the film material may also be printed with a pattern and at the same time be provided with visibility into its interior. The front side wall 14 is shown here with a printed target area 17 for alerting the user, preferably to puncture the bag there. Of course, the straw may also puncture the bag in other areas, but preferably at each corner.

The liquid product 11 contained in the bag occupies about 60% to about 90% of the volume of the cavity 13. A sufficient amount of air is displaced from the volume remaining in the cavity so that the liquid can be displaced by collapsing the side walls against each other to facilitate grasping of the straw. Preferably, but not exclusively, the liquid product occupies about 84% of the volume of the cavity. Further, the bag is preferably, but not limited to, sized to hold a volume of liquid product ranging from 3 ounces to 24 ounces (85 milliliters to 675 milliliters).

As shown in fig. 2A and 2B, the plastic film pouch 10 is rectangular and has a bottom seal 18, opposed side seals 19 and 19', and a top seal 20 which surround the opposed side walls 14 and 15 to form a rectangular transparent film pouch. It should be noted that the blister pack need not be completely transparent, as in fig. 2B, the rear side wall 15 is painted with a paint to provide an opaque purely colored wall. Alternatively, an opaque color may be printed on the portion 14' of the front wall 14, leaving the next large transverse transparent segment 14 "for viewing of the straw 12 in the bag. Of course, printing may also be added across the transparent segment 14 "with the assurance that the straw position is visible through the transparent segment.

Referring now to fig. 3 to 5, the method of using the plastic film pouch, i.e., how to pierce the pouch with a straw to discharge the liquid, will be explained. As shown in figure 4, since air has been expelled from the plastic film pouch, the opposing side walls 14 and 15 can be squeezed between the fingers to collapse and grasp the straw 12 with one hand. In this way, the user can move one end of the straw adjacent to the target area 17 shown in FIG. 3. A user grasps one corner region 23 of the bag with the fingers 22 of the other hand and bends it downwardly along arrow 24 against the free end 12 ' of the straw so that the target region 17 or a region adjacent thereto is pulled toward the free end 12 ' so that the free end 12 ' pierces the film and emerges from the bag as shown in fig. 5.

In order to provide good sealing between the side wall 12 "of the straw and the puncture hole 25, a multi-layer resinous film material is used with an inner sealing layer 26. The multilayer film material is shown in fig. 6 and comprises a laminated or extrusion coated plastic film comprising an inner sealant layer 26 of a material selected from a linear low or very low density ethylene-octene copolymer or a metallocene linear low density polyethylene. Preferably, the sealing layer has 0.900g/cm³Or a density of the above. The coextruded resin film also carries at least one different outer polymer 27 or an additive, which is preferably a multilayer resin film, blended with high pressure polyethylene or other linear low density ethylene-octene copolymers. If desired, a colored resin core 28 may be provided to provide the bag with an opaque back wall 15 as previously described. The core may be a barrier material such as nylon, PET (polyethylene terephthalate), PVDC (polyvinylidene chloride), PP EVOH (polypropylene ethylene vinyl alcohol resin). Such a multilayer resin film allows the construction of a bag having excellent impact resistance and flexibility to prevent leakage, and having a low heat-seal initiation temperature to seal the film bag at high speed. The resulting bag is preferably made strong and free of defects, that is, holes or creases that could cause leakage of the bag.

Since the bag is typically manufactured on a vertical form, liquid-filled, sealed type packaging machine, the hot tack properties of the film are very important. In the multilayer film shown in fig. 6, different resins or additives are combined in one or more layers to achieve specific properties for bag 10. As noted above, an important aspect of such multilayer films is the inner seal layer 26. Metallocene low density ethylene-octene copolymers are preferred because they do not impart an off-note taste, i.e., the liquid product does not impart a sour taste to the liquid when held in the bag for an extended period of time. This also extends the shelf life of the liquid product in the bag. Other polymeric materials, such as EVOH (ethylene vinyl alcohol resin) or PET (ethylene terephthalate polyester), may also be used to provide barrier properties to the bag. In addition, low cost LLDPE (linear low density polyethylene) butene or LDPE (low density polyethylene) can be used in the core to reduce cost.

Referring to figure 5, it will be appreciated that, because the inner sealing layer 26 has a self-sealing property substantially around the straw, it forms a sealing membrane 29 around the side wall 12 "of the straw to prevent liquid from escaping through the puncture hole 25. The liquid in the straw can be expelled by squeezing the bag, thereby squeezing the liquid out through the straw 12, or alternatively, the liquid can be sucked out of the free end 12' of the straw.

Any obvious modifications to the preferred embodiments described herein, which are within the scope of the appended claims, are deemed to be covered by the scope of the invention.

Claims (4)

1. A plastic film pouch (10) for containing a liquid product (11), said film pouch having opposed side walls (14-15) sealed at a periphery (16) to form a sealed interior cavity (13), at least a portion of at least one of said side walls being formed of a transparent plastic material to allow visual access to said interior cavity (13), a straw (12) of a predetermined stiffness being freely disposed within said interior cavity, said straw (12) being shorter in length than said side walls, a liquid (11) being contained within said interior cavity, said straw being freely buoyant in said liquid and being movable in the liquid across said side walls of said interior cavity, said liquid contained within said interior cavity occupying from about 60% to about 90% of the volume of said interior cavity (13), characterized in that a sufficient amount of air is displaced from the remaining volume of said interior cavity, such that when said side walls (14-15) are collapsed towards each other, said liquid is able to move within said cavity to grasp said straw (12) free floating in said liquid (11) and to penetrate said straw through said plastic film pouch so that a portion of said straw projects outside said pouch to draw liquid from said pouch.

2. The bag according to claim 1, wherein said liquid product (11) occupies about 84% of said volume of said inner chamber (13).

3. Pouch according to claim 1, characterised in that in a vertex region of an outer surface of said pouch there is provided indication means (17) to indicate to the user to align a free end (12') of said straw (12) intended to penetrate said pouch (10) therewith.

4. The bag according to claim 1 wherein said bag is sized to contain a volume of said liquid (11) of from 85 ml to 675 ml.