AU746228B2

AU746228B2 - Liquid plastic film pouch with inner straw and machine and method of making

Info

Publication number: AU746228B2
Application number: AU54707/98A
Authority: AU
Inventors: Harland Beach Jr.; John Edwards; Raymond L. Larson; Rick Savoury
Original assignee: Glopak Inc
Current assignee: Glopak Inc
Priority date: 1997-02-28
Filing date: 1997-12-11
Publication date: 2002-04-18
Anticipated expiration: 2017-12-11
Also published as: JP2001516313A; DE69714471D1; CN1253534A; AU5470798A; ATE221498T1; DE69714471T2; WO1998038110A1; EP0963327A1; EP0963327B1; BR9714564A; HK1028007A1; CN1081159C; ES2181045T3; CA2266669A1

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

2. LIQUJID PLASTIC FILM POUCH WITH INNZ"R STRAW TRCM.NICAL FIELD The present invention relates :0 a sealed plastic film pouch containing a liqu'.d and a freefloating straw therein and wherein air is evacuated from a space within the pouch to faci'itate the manipulation of the pouch by collapsing its side walls to grasip the straw and puncture the pouch, and further wherein the bag iS formed from a multilayer film having an inner sealant layer exhibiting a selfsealing behavior about the straw in the punctured area to provide a seal about the straw.

P;ACKGROUNZ)

ART

it is known to form package liquid containers with sealed plastic bags and wherein a straw-like object or extractor is held inside the bag anid freely floating within the liquid contained zo therein. Such a liquid pouch container is, for example, described and illustrated in U.S. Patent 3,730,336 issued on May 1, 1973. Such package containers, however, have disadvanztages in that it becomes difficult to manipulate the bag to grasp the straw and puncture the bag due to th-e amount of liquid and air held capt~.ve within the sealed hoag. This manipulation often causes the bag to burst. It is also important to have an added extra volume within the bag in the event that it -is desirable to freeze AENDED SHEET

RAQ

-7 WO 98/38110 PCT/CA97/00964 2 the package with its liquid content as the extra volume will permit for expansion of the freezing liquid content.

It is desirable with such bags to provide straws with sufficient rigidity, such as polypropylene to puncture the bag without having an end of the straw cut on the bias and without having any means attached to the straw to permit its grasping to facilitate its movement within the bag as such means pose other disadvantages in the automatic assembly of the pouch with its liquid contents. It is also desirable with such package liquid containers to provide a container which is highly hygienic and which is formed of plastic material which will not impart off-taste (acidic taste) to a liquid contained therein and particularly if the liquid is present for a long period of time. It is further desirable with such packages to extend the shelf life thereof so that such packages with their liquid content can be maintained a long period of time before being used. It is also desirable to provide a plastic film pouch which can provide a seal about the straw when the bag is punctured and which can resist impact during handling and shipping.

It is also known to manufacture plastic film liquid pouches with a free-floating straw positioned therein. Certain methods of manufacture utilize forming the pouches by folding a film sheet horizontally and placing a straw in the lower folded section of the film strip well before the seals are made to produce an open-ended pouch with a straw therein ready to receive liquid. However, when producing such pouches from vertical forming machines where the film tube is formed in a vertical manner and particularly in a continuously liquid dispensing application, this task becomes much more difficult as 3 the straw must be positioned within the bag being formed as liquid is admitted in the bag due to the continuous liquid dispensing process. This poses several problems, one being the manner in which the straws can be dispensed into the liquid pouch being filled and also in synchronism with the pouch sealing cycle. Another problem is to ensure that the straw does not extend into the seal jaws after the openended pouch formed in the plastic tube is disposed for sealing the open top end to form the pouch. Another problem is to adapt straw dispensing mechanism to such bag forming and filling machines. It is also desirable, during the manufacture of these sealed liquid pouches, to evacuate 'some air from the space which is formed in the bag and which is necessary to provide for the expansion of the liquid, when it is frozen.

GB-A-789 368 teaches a plastic film pouch for containing a liquid product. The film pouch has opposed side walls sealed about a peripheral edge thereof to define a sealed inner chamber. At least a portion of at least one of the side walls is formed of transparent film for visual access to the Inner chamber. A straw is located freely within the inner chamber. A liquid is contained within the inner chamber and occupies a certain volume of the inner chamber, wherein the straw can be grasped in said liquid and can be manipulated to puncture the plastic film pouch whereby to extend a portion of the straw exteriorly of said pouch to extract liquid from said pouch. The patent does not teach the expulsion air tc facilitate grasping the straw.

AMENDED SHEET Z B 3a SUMIMARY OF INVI NTICN it is therefore a feature of the present invention to provide a plastic film pouch which overcomes the above -ment ioned disadvantages of the prior art and which provides for the needs as abovementioned.

Another feature of the present invention i-s to provide a sealed plastic film pouch having a liquid and a free-floating straw therein and wherein a predeterrined quantity of air has been evacuated from a space contained wiJthin the inner chamber of the pouch.

Another feature of the present invention is provide a sealed plastic film pouch containing a liquid and a free-floating straw therein and wherein the plastic film is a Twultilayer film having an inner sealanrt layer possessing a substantially self-seal-Lng behavior about the straw in a punctured area of the t-t P:\OPERJcc\'54707-98 spc dOc-2810/01 -4bag when in use whereby to provide a seal about the straw.

Another feature of the present invention is to provide a method of forming a plastic film pouch with a liquid and straw disposed in the pouch and which substantially overcome the above disadvantages of the prior art and which meets the required needs.

According to the above features, from a broad aspect, the present invention provides a plastic film pouch for containing a liquid product. The film pouch has opposed side walls sealed about a peripheral edge thereof to define a sealed inner chamber. At least a portion of at least one of the side walls is formed of transparent film for visual access to the inner chamber. A straw of predetermined rigidity is located within the inner chamber. The straw has 15 a length shorter than the side wall. A liquid is provided within the inner chamber. The straw is free floating in the liquid and displaceable in the liquid across the side walls of the chamber. The liquid contained within the inner chamber occupies from about 60% to about 90% of the volume of the inner chamber. The pouch is characterized in that the remaining volume of the inner chamber has a portion of air evacuated therefrom in sufficient quantity to permit the liquid to be displaced within the inner chamber when the side walls are collapsed towards one another to grasp the free floating straw in the liquid and manipulate it to puncture the plastic film pouch whereby to extend a portion of the straw exteriorly of the pouch to extract liquid from the pouch.

The pouch may include indicator means provided on an exterior surface of said pouch in a top corner area thereof to indicate to a user person where to orient a free end of said straw intended to puncture said bag.

P:\OPERJcc\54707-98 spec.do-28/08/01 Typically, the plastic film is a multilayer film having an inner sealant layer and at least a different outer polymer or additive, said inner sealant layer being a low density copolymer or polyethylene which does not impart acidic taste.

BRIEF DESCRIPTION OF DRAWINGS A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which: FIG. 1 is a perspective view showing a plastic film pouch constructed in accordance with the present invention and wherein a liquid and a straw is contained within an inner chamber formed by the sealed 15 pouch; FIG. 2A is a plan view of the plastic film pouch of FIG. 1 and wherein the pouch is formed entirely of transparent plastic materials; FIG. 2B is a plan view showing the plastic 20 film pouch formed with an opaque rear wall and a partly opaque and partly transparent front wall; FIG. 3 is a perspective view showing how the straw inside the plastic film pouch is manipulated to puncture a corner portion of one of the side walls whereby a portion of the straw can be exposed to extract liquid from the pouch; FIG. 4 is a perspective view showing the pouch partly in section to show how the side walls of the pouch are collapsed to grasp the straw; FIG. 5 is an exploded view showing a sealing membrane formed about the straw by the inner sealant layer of the film which exhibits a selfsealing behavior; and FIG. 6 is a section view showing the composition of the multilayer resin film.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to the drawings and more particularly to Figure i, there is shown generally at the sealed plastic film pouch of the present invention. A liquid product 11, as well as a free floating straw 12, are contained within an inner chamber 13 of the pouch 10. The plastic film pouch has opposed side walls 14 and 15 which are sealed about a peripheral edge 16 thereof. As hereinshown the pouch 10 is formed of transparent film material whereby to provide visual access to the free-floating S: *straw 12 and the liquid product. Of course, the film material may be printed while still providing visual access to the inner chamber thereof. As hereinshown 15 the front side wall 14 is provided with a printed target area 17 to indicate to the user where it is preferable to puncture the bag, although the straw can be oriented to puncture other areas, but the corners oe are preferred.

The liquid product 11 contained within the bag occupies from about 60% to about 90% of the volume of the inner chamber 13. The remaining volume of the S. inner chamber has a portion of air evacuated therefrom in sufficient quantity to permit the liquid to be displaced by collapsing the side walls against one another to facilitate grasping of the straw.

Preferably, although not exclusively, the liquid product contains approximately 84% of the volume of the inner chamber. Also, these pouches are preferably, although not exclusively, dimensioned to contain liquid products in volumes from 3 ounces to 24 ounces (85mi to 675m1) As shown in Figures 2A and 2B, the plastic film pouch 10 is of rectangular shape and is provided with a bottom seal 18, opposed side seals 19 and 19' and a top seal 20 about the opposed side walls 14 and whereby to form a rectangular transparent film pouch. It is pointed out that the film pouch need not be entirely transparent and as shown in Figure 2B, the rear side wall 15 is formed with a pigment to provide a solid colored wall which is not transparent. On the other hand, the front wall 14 may have opaque colors printed on portions 14' thereof while maintaining a large transverse transparent section 14' fort visual access of the straw 12 located within the pouch. Of course, printed matter may also be applied across the transparent section 14", provided one can still see through the transparent section to locate the straw.

With reference now to Figures 3 to 5, there will be described the manner in which the plastic film 15 pouch is used to puncture it with the inner straw and to extract the liquid. As shown in Figure 4, because air has been evacuated from the pouch, it is possible to collapse the opposed side walls 14 and 15 by pinching the pouch with the fingers 21 to grasp the 20 straw 12 with one hand. This permits the user to manipulate the straw to position an end thereof adjacent the target area 17 as shown in Figure 3.

With the fingers 22 of the other hand, the user grasps a corner area 23 of the pouch and folds it downwardly in the direction of arrow 24 against the straw free end 12' with the target area 17 or an area close thereto being pulled against the free end 12' whereby the free end 12' will puncture the film and exit the bag as shown in Figure In order to obtain a good seal between the straw side wall 12" and the punctured hole 25, a multilayer resin film material having an inner sealant layer 26 is utilized. Such a multilayered film material is illustrated in Figure 6 and it consists of a laminated or extrusion-coated plastic film comprising an inner sealant layer 26 which is selected w7from a linear low or very low density ethylene, e.g. very low density ethylene-octene, copolymer or a metallocene linear low density polyethylene. Preferably, the sealant layer has a density of 0.900 g/cm 3 and above. The coextruded resin film also has at least a different outer polymer 27 or an additive which is preferably a multilayer resin film blend of high pressure polyethylene or other linear low density ethylene-octene copolymer.

It may also have a pigmented resin core 28 if it is desirable to form the pouch with an opaque back wall 15 as previously described. The core could be a barrier material, such as Nylon, PET, PVDC, pp EVOH, f or example. Such a multilayer resin film provides for the fabrication of a pouch having excellent impact and flexural properties to prevent leaking and exhibits low heat seal initiation temperatures to permit high speed sealing of the pouch. It is preferable with these pouches that they be strong and 2. defect-free, that is to say that there are no pin 20 holes or folds which could lead to leaking pouches.

"As the pouches are typically made on a vertical formed fill seal packaging machine, the hot tack properties of the film are important. The multilayer film as shown in Figure 6 combines different resins or additives in one or more layers in order to achieve specific performance properties of the pouch 10. As above-described, the important aspect of this multilayer film is the inner sealant layer 26. Metallocene low density ethylene-octene copolymer is preferred as it does not impart offtaste, that is to say it does not impart an acidic taste. to the liquid product when contained within the bag over a long period of time. It also improves the shelf life of the liquid product within the pouch.

Another polymer material such as EVOH or PET could be used to provide barrier characteristics to the pouch.

r PAOPER\Jcc\547O7.98 sp-.do-.S1/8/0 Furthermore, lower cost LLJDPE butene or LDPE could be used in the core to reduce costs.

With reference to Figure 5 it can therefore be appreciated that because the inner sealant layer 26 exhibits a substantially self-sealing behavior about the straw, it forms a sealing membrane 29 all about the straw side wall 12"1 to prevent liquid from seeping through the punctured hole 25. The liquid product from the straw can be extracted squeezing the bag to expulse the liquid through the straw 10 12 or else the liquid may be sipped out the pouch through the free end 12' of the straw.

It is within the ambit of the present invention to cover any obvious modifications of the preferred embodiment described herein, provided such modifications fall within the scope of the appended claims.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any :form of suggestion that that prior art forms part of the common general knowledge in Australia.

S

Claims

1. A plastic film pouch for containing a liquid product, said film pouch having opposed side walls sealed about a peripheral edge thereof to define a sealed inner chamber, at least a portion of at least one of said side walls being formed of transparent film for visual access to said inner chamber, a straw of predetermined rigidity located within said inner chamber, said straw having a length shorter than said side wall, a liquid within said inner chamber, said straw being free floating in said liquid and displaceable in too: t oo said liquid across said side walls of said chamber, said liquid contained within said inner chamber occupying from about 60% to about 90% of the volume of said inner chamber, 15 characterized in that the remaining volume of said inner go chamber having a portion of air evacuated therefrom in sufficient quantity to permit said liquid to be displaced gee• within said inner chamber when said side walls are collapsed to: towards one another to grasp said free floating straw in said liquid and manipulate it to puncture said plastic film pouch whereby to extend a portion of said straw exteriorly of said pouch to extract liquid from said pouch.

2. A pouch as claimed in claim 1 wherein said liquid product contains approximately 84% of said volume of said inner chamber.

3. A pouch as claimed in claim 1 or claim 2 wherein indicator means is provided on an exterior surface of said pouch in a top corner area thereof to indicate to a user person where to orient a free end of said straw intended to 30 puncture said bag. P:OPERUcc\54707-98 spc.doc-28/08/01 -12-

4. A pouch as claimed in any one of claims 1 to 3 wherein said pouch is dimensioned to contain said liquid product in volumes from 85ml to 675m1. A pouch as claimed in any one of the preceding claims wherein said plastic film is a multilayer film having an inner sealant layer and at least a different outer polymer or additive, said inner sealant layer being a low density copolymer or polyethylene which does not impart acidic taste. 10 6. A pouch as claimed in claim 5 wherein said inner sealant layer is selected from a linear low or very low density ethylene copolymer, or metallocene linear low density polyethylene. *000

7. A pouch as claimed in claim 6 wherein said inner 15 sealant layer has a density of 0.900 g/cm 3 and above.

8. A pouch as claimed in claim 5 wherein said multilayer film is composed of a blend of linear low, very low density or metallocene polyethylene with high pressure polyethylene or other linear low density ethylene-octene copolymer to provide a pouch with excellent impact and flexural properties and to prevent leaking, said multilayer resin film also exhibiting low heat seal initiation temperatures to permit high speed sealing of said pouch.

9. A pouch as claimed in claim 5 wherein said inner sealant layer of said multilayer resin film forms a membrane which exhibits a substantially self-sealing behavior about said straw in the area of said puncture due to the fact that the yield point of said inner sealant layer has not been R exceeded. _t 7. PAOPER*65'47O7-98 spa.doc.29/O8/01 13 A pouch as claimed in claim 6 wherein said ethylene copolymer is octene or other copolymner.

11. A pouch as claimed in claim 1 and substantially as hereinbe fore described. DATED this 29th of August, 2001 Glopak, Inc. by DAVIES COL 1 LISON CAVE Patent Attorneys for the Applicant(s) 0.0. *se S 0