NZ200957A - Making multilayer flexible container pouches - Google Patents

Description

NEW ZEALAND PATENTS ACT, 1953 No.: Date: COMPLETE SPECIFICATION Improvements in and relating to a multilayered flexible container pouch and a method of making it. l!/We, AHI OPERATIONS LIMITED, a company duly incorporated under the laws of New Zealand of 640 Great South Road, Manukau City, Auckland, New Zealand hereby declare the invention for which % / we pray that a patent may be granted to jsxc/us, and the method by which it is to be performed, to be particularly described in and by the following statement:- 2009 5 7 This invention relates to a multilayered flexible container pouch and to a method of making.it. Multilayered flexible container pouches are known for packaging liquids such as wine and milk- Such pouches are often provided with a valve or tap member through which the liquid contained may be dispensed in a controlled fashion.

Whilst the multilayered flexible container pouches known are generally suitable for the packaging of wines and . other materials which do not need to be packaged under stringent sterile conditions, sterility problems can arise where materials are packaged that will be adversely affected by bacteria and other contaminants.

The object of the present , invention is to provide a multilayered flexible container pouch amenable to packaging under relatively sterile or aseptic conditions.

The present invention provides in one aspect a method of making a multilayered flexible container pouch including the steps of: forming as a longitudinally extending strip, two layers of heat weldable material to provide an inner bag; encasing said inner bag layers between a pair of outer bag layers of hfeat weldable material; and heat welding said layers laterally and longitudinally of said strip to provide a series of container pouches each comprised by a sealed inner bag encased within^ an outer bag and to provide a spout zone at an edge of each pouch where said outer bag is not heat welded to said inner bag.

In another aspect of the present invention there is provided a multilayered flexible container pouch including a sealed outer bag and a sealed inner bag where the outer bag is heat sealed to the inner bag adjacent the perimeter thereof except at a spout.zone where the bags are not joined together. This means that the inner bag may be kept in a sealed and aseptic condition. Access is available through the spout zone. The inner bag may be pierced for filling.

In one aspect of the present invention the inner bag layers are provided by a strip of heat weldable material that is folded over to provide a tube. The longitudinal edges of the tube may be heat welded together to form a continuous tube prior to the heat welding of the layers in the bag making process. However if preferred the longitudinal edges of the tube may be heat welded during the.heat welding process during the bag manufacture. In either event the weld seal of the inner tube is preferably at the edge remote from the spout. This is a preference so that when the inner bag is pierced for filling piercing is affected at a portion of the inner bag that does not include a joint. That is to say it is a plain face and this is -easier to penetrate.

In a further alternative the inner bag layers are provided by an extruded tube of heat weldable material so that it is not necessary to have a longitudinally extending joint at all.

The inner bag layers may be made of any suitable plastics material that is heat weldable. Such materials are well known in the art and suitable examples are polyethylene, polyvinylidene chloride, eval and laminates of these and other materials.

The outer bag layers are also preferably provided by a strip of heat weldable material that in one example may be folded over to encase the inner layers. The longitudinal edges-are preferably heat welded -together -during the bag — making process. In one. embodiment the outer layers are provided by a tube of heat weldable material extruded around the extruded tube that comprises the preferred inner bag. In this example it is preferred that the outer and inner tubes be extruded at the one time to provide a pair of tubes one within the other.

The heat welding preferably provides a pair of spaced apart lateral welded seals formed at the junction of adjacent pouches to define a severable web therebetween. If desired the web may be severed at the time of the welding so that the product will be in the form of separate pouches. Alternatively the severable web may be provided with some perforations to assist in the subsequent separation of the pouches such as after filling with product. Thus the pouches may be provided in a continuous web for use with automatic filling machinery and the like. This allows for packaging in a roll or in a stack as desired.

Preferably the heat sealing along the pouch edge . provided with the spout zone extends longitudinally over a substantial portion where the.inner and outer layers overlap so that the bags will be joined in the zones. However at the spout zone it is preferred that the heat sealing extend laterally to define that zone. In one example heat sealing extends across the mouth of the spout but only over the area of the outer bag so that in use the outer portion of the spout zone may be cut away to allow access to the inner bag. In one example a handle may be cut into the portion of the pouch outside the sealing bag and adjacent the pouch zone. This portion may be cut away if desired and preferably this is done at the time of the. heat welding.

Any number of intermediate layers may be included in the construction as is desired. Generally- these will be heat sealed as is the outer bag components but if desired one or more intermediate layers may be heat sealed as the inner layers are sealed thus to require penetration for filling. Those skilled in the art will appreciate that these intermediate layers may be included for special requirements such as a reduction in oxygen permeation or the like.

^ The invention will now»be further described with reference to the accompanying CuawinijjD which ^onow in plan a series of pouches joined end to end. In the drawings there is an outer bag tube enveloping an inner bag tube shown generally at .14. The outer bag tube provides longitudinal edges 1 and 2 and the inner bag tube provides longitudinal edges 3 and 4. A number of regularly spaced heat seals 5 are applied laterally of the composite web to form a series of flexible pouch packages joined end to end. As shown it is preferred that the heat seals 5 are applied in spaced apart pairs to provide a severable web therebetween.

Perforations 6 may be provided if desired. The severing of the web may be performed during the heat sealing process or if it is desired to produce individual packages rather than a continuous web of bags the perforation line 6 may be replaced by a complete cutting off operation during heat . sealing process.

The line of heat sealing 7 extends longitudinally over a portion where the inner and outer tubes overlap to define portion 10 and the spout zone generally designated 8 which is sealed off by the edge 4 of the inner tube. It _ 4 _ 2 0095 7 may also be sealed off by the edge of the sheath 2 depending upon whether it is desired to allow the edge to be opened or sealed as the occasion demands. During the heat sealing operation to perform the heat seal designated by the line 7 the layers forming the shaded area 10 may also be heat sealed together and a cut out portion 11 may be provided in this area to facilitate hand holding of the package after it has been filled and removed from the web if desired. In one embodiment the heat seal may extend across the spout zone 8 outside of the edge 4 to seal the outer bag.

As the interior of the pouches formed in accordance with the foregoing description is completely sealed the prospect of contamination is minimal. The package is ideally suited for aseptic packaging of product.

■ Most suitably a continuous line of packages in the m form of a wound or folded stack will be supplied to a ' packager who may then feed the web directly into filling machinery. To assist him in this purpose a series of sprocket holes may be provided along the shaded portion 10 if desired. 0 Such sprocket holes may also facilitate correct registration of the spout zone under the filling orifice of automatic filling machinery.

If the edge 2 of the sheet is sealed the filling machinery may cut off the marginal edge portion of the package at 2 to open the edges of the outer tube and allow the filling equipment to gain access to the spout region 8. The filling equipment may be provided with a pointed probe which pierces the edge of the inner bag 4 to allow for filling of the package. Subsequent to the filling of each pouch with product a heat seal may be applied across the area denoted by the bottom lines 13 to reseal the package at which time the filled packages may be separated from each other and supplied to the next person in the chain of marketing distribution.

It will be appreciated that during the filling operation in accordance with the preferred arrangement of the present invention the filling nozzle does not have to break across or penetrate any heat sealed portions of the bag. The bag construction may be sterilised as is known in the art and the filling proceedure may be performed under sterile conditions.

It will be appreciated that various modifications, additions and alterations may be made to the above described method and construction without departing from the ambit of the invention defined in the claims annexed hereto. 1^957

Claims (19)

WHAT WE CLAIM IS: '

1. A method Of making a multilayered flexible container pouch including the steps of: forming as a longitudinally extending strip, two . layers of heat weldable material to provide ah inner" bag;* encasing said inner bag layers between a pair of outer bag layers of heat weldable material; and heat welding said layers laterally and longitudinally of said strip to provide a series of container pouches each comprised by a sealed inner bag encased within an outer bag and to provide a spout zone at an edge of each pouch where ^aid outer bag is not heat welded to said inner bag.

2. A method as claimed in claim 1, wherein one or more intermediate pairs of bag layers are provided between respective inner bag layers and outer bag layers thereby to provide one or more intermediate bags in said pouch.

3- A method as claimed in claim 1 or claim 2, wherein said inner bag layers are provided by a strip of heat weldable material folded over to provide a tube.

4. A method as claimed in claim 3 wherein the longitudinal edges of said tube are heat welded to form a continuous tube prior to said heat welding of said layers.

5. A method as claimed in claim 3, wherein the longitudinal edges of said tube are heat welded by said heat welding of said layers longitudinally.

6. A method as claimed in claim 1 or claim 2 wherein said inner bag layers are provided by an extruded tube of heat weldable material .*

7. A method as claimed in any preceding claim, wherein said outer bag layers are provided by a strip of heat weldable material folded over and wherein the longitudinal edges thereof are joined by said heat welding.

8. A method as claimed in claim 6, wherein said outer layers are provided by a tube of heat weldable material extruded around the extruded tube comprising said inner bag.

9. A method as claimed in any preceding claim, wherein during said heat welding pairs of spaced apart lateral welded seals are formed at the junction of adjacent pouches - 7 - 57 to define a severable web therebetween.

10. A method as claimed in claim 9 wherein during said heat welding step, said severable web is provided with perforations to assist in subsequent separation of the pouches. •

11. A method as claimed in claim 9, wherein during said heat welding step adjacent pouches are separated at said web.

12. A method as claimed in any preceding claim, wherein said spout zone is provided by said heat welding extending along the pouch edge provided with said spout zone, /(? jL longitudinally over a portion where said inner and outer (M , , SaJtiL . . . & P layers overlap, thus to seal-siad inner and said outer bags together, and laterally adjacent said spout zone so that over said spout zone said inner and said outer bags are not joined together.

13. A method as claimed in claim 12, wherein said outer bag is heat sealed longitudinally across said spout to seal said outer bag and define said spout zone.

14. A method as claimed in claim 12 or claim 13, wherein during said heat welding a handle is cut into the portion of the pouch outside of said sealed bag and adjacent said pouch zone.

15. A method of making a multilayered flexible container ,0 / pouch substantially as hereinbefore described with reference lrl to the accompanying •drawing^T

16. A multilayered flexible container pouch when prepared by a method as claimed in any preceding claim.

17. A web of multilayered flexible container pouches when prepared by method as claimed in any preceding claim.

18. A multilayered flexible container pouch including a sealed outer bag and a sealed inner bag, said outer bag being sealed to said inner bag adjacent the perimeter thereof, except at a spout zone, where said bags are not joined together.

19. A multilayered flexible container pouch substantially as hereinbefore described with reference to the accompanying *tirbd£. 'W? DATED THISlV+k DAY OFTu^L^a. A. J. PARK 8c SON 9/ IW enP.C&o AGENTS FOn THE APPLICANT