P/00/009A Section 29 AUSTRALIA Patents Act 1990 INNOVATION PATENT SPECIFICATION Invention Title: IMPROVED SEAL ARRANGEMENT FOR A STORAGE BAG Applicant: Andrew Kohn Pty Ltd The invention is described in the following statement: 7019 2 IMPROVED SEAL ARRANGEMENT FOR A STORAGE BAG Field of the Invention 5 The present invention relates generally to resealable storage bags and, in particular, to a storage bag well suited for packaging foodstuffs or the like. Background to the Invention Storage bags constructed of polyester, polypropylene, polyethylene or the like 10 are well suited for storage of various items including foodstuffs and other consumables. Bags constructed from such materials are inexpensive, hygienic and liquid-tight. Typically, a consumer purchasing the foodstuff or other item will wish to continue to store the foodstuff or other item in the storage bag once the bag has been 15 opened for the first time, for example to consume only a portion of the foodstuff. Storage bags that can be resealed after use are known in the art and quite popular among consumers for their convenience. One particular style of bag includes a moulded plastic zipper-style seal arrangement. Such zipper-style seals have a mating male rib or bead and a complementary female channel extending along the 20 opening of the bag. The zipper-style seal forms an airtight closure when the male rib and female channel are properly aligned and pressed together along the length of the bag opening. A problem with providing resealable closures or seals in storage bags is that the integrity of the bag is compromised by provision of the seal since the zipper-style 25 seal is not liquid-tight. To address this problem as well as making the strogae bag tamper-proof, it is known to provide a heat seal outside of the zipper-style seal to hermetically seal the storage bag after it has been filled and air has been evacuated from the bag. This heat seal is typically torn from the storage bag by the consumer at the time of first 30 opening the storage bag to allow access to the primary zipper-style seal. Since the zipper-style seal itself is not liquid-tight, when liquids or foodstuffs having a liquid component are stored in the storage bag, the liquid has a tendency to escape past the zipper-style seal to the header space provided between the zipper style seal and the secondary seal. When this occurs, opening the secondary seal 904425 3 and/or the zipper-style seal becomes an unpleasant and messy experience for the consumer when liquid leakage occurs. It is therefore an object of the present invention to provide an improved seal arrangement for a storage bag to ameliorate the problems associated with the prior 5 art. Summary of the Invention According to an aspect of the present invention, there is provided a storage bag including: a first sheet having a top edge, a bottom edge, a first side and a 10 second side; a second sheet having a top edge, a bottom edge, a first side and a second side; the first sheet being joined to the second sheet at corresponding bottom edges, first sides and second sides to form a pouch having an opening provided by the corresponding top edges of the first and second sheets; the pouch being sealable by means of a zipper-style seal including a male rib and a female channel extending 15 along the opening of the pouch to form a resealable closure when the male rib and female channel are aligned and pressed together; and an auxiliary seal positioned within the pouch sealed by the zipper-style seal and in proximity to the zipper-style seal. The storage bag may be of the type used for distribution and storage of 20 foodstuffs or other consumable items. Such bags are typically formed of plastics such as polyester, polypropylene, or the like. The auxiliary closure preferably provides a liquid tight seal that is broken upon a first opening of the pouch to access content stored therein. The auxiliary seal may be a heat seal and may extend substantially parallel to 25 the zipper-style seal. In a preferred embodiment, the auxiliary seal is approximately 5 mm wide. In another preferred embodiment, the strength of the auxiliary seal is 3 to 4 N/25mm. 30 Brief Description of the Drawings It will be convenient to hereinafter describe the invention in greater detail by reference to the accompanying figures which facilitate understanding of the method according to this invention. The particularity of the figures and the related description 904425 4 is not to be understood as superseding the generality of the broad identification of the invention as given in the attached claims. Figure 1 is a schematic view of the storage bag of the present invention. Figure 2 is a schematic view of the storage bag according to another 5 embodiment. Figure 3 is a cross sectional view of a heat seal bar showing the profile of the heat seal bar according to an embodiment. Figure 4 is a cross sectional view of a cool seal bar corresponding to the heat seal bar of Figure 3 according to an embodiment. 10 Detailed Description Referring firstly to Figure 1 there is shown a storage bag 100 in accordance with an embodiment. The storage bag 100 is formed generally from two sheets, the first sheet 110 (shown) has a top edge 120, a bottom edge 130, a first side 140 and a 15 second side 150. A second sheet which lies behind the first sheet (not shown) also has a top edge, a bottom edge, a first side and a second side. The first sheet 110 overlays and is joined to the second sheet at corresponding bottom edges, first sides and second sides to form a pouch. The corresponding top edges of the first and second sheets provide an opening 160 to the pouch through which items are placed 20 into or removed from the storage bag 100. The opening 160 is releasably sealable by means of a zipper-style seal 170. The zipper-style seal is of the type including a male rib 180 and female channel 190 both extending along the length of the pouch opening 160. This type of seal provides a resealable closure wherein the male rib 180 and female channel 190 are properly 25 aligned and pressed together to close the opening and the male rib is removed from the female channel to open the pouch. An auxiliary seal 200 is positioned within the pouch sealed by the zipper-style seal and in proximity to the zipper-style seal. That is, when considering the orientation of the storage bag 100 shown in Figure 1, the auxiliary seal 200 is positioned beneath 30 the zipper-style seal. The auxiliary seal extends substantially parallel to the zipper style seal. The function of the auxiliary seal is substantially to protect the zipper-style seal from liquids in particular, such as when storing foodstuffs or other products that have a liquid component within the storage bag 100. 904425 5 Referring now to Figure 2, there is shown an alternative version of the storage bag which includes the secondary seal 220 to hermetically seal the bag after filling and evacuation of air from the bag. This secondary seal 220 is torn off the storage bag 100 by the consumer, using the "tear here" tabs 230 at the time of first opening 5 the bag. The storage bag of the present invention has particular utility for storage of meat which has a tendency to leak meat juices. The auxiliary seal 200 prevents the meat juices from leaking into or through the zipper-style seal to prevent the meat juices from escaping through the zipper-style seal and into the header space formed 10 between the zipper-style seal and any secondary seal 220 that has been provided. Without the auxiliary seal 200, the consumer is likely to have an unpleasant experience when upon tearing off the secondary seal to provide access to the resealable zipper-style seal and the contents of the storage bag the liquids, such as meat juices, spill out of the header space 240. Provision of the auxiliary seal 200 15 addresses this problem by preventing any liquids from penetrating the zipper-style seal 170. In accessing the contents of the storage bag 100 for the first time, the consumer opens the zipper-style seal 170 by removing the male rib 180 from the female channel 190, usually be exerting a sideways pressure on the zipper-style seal. 20 Once the resealable zipper-style seal is open, the consumer opens the auxiliary seal which is in effect a temporary seal by a similar action, i.e. pulling the first sheet 110 apart from the second sheet (not shown). Once the auxiliary seal 200 is broken, it can not be resealed. That is, the main function of the auxiliary seal 200 is to prevent the leakage of liquids through the zipper-style seal during freight, distribution and 25 handling before the storage bag and its content reach the consumer. This ensures not only that the consumer does not have a messy experience upon first opening the bag, but also maintains the appearance of the storage bag and its contents to maintain its visual appeal for marketing purposes. The auxiliary seal 200 is formed in a manner such that when the seal is 30 broken, it does not result in destruction of the bag itself. This "peel seal" effect is achieved using a blend of polyethylene (LDPE) and polybutene. This combination produces a heat seal with a reduced bond strength that will allow separation of the first and second sheets under pressure. 904425 6 The corresponding bottom edge 130, first side 140 and second side 150 of the first and second sheets are also bonded together by a heat seal. However, these bottom and side seals (which are not intended to be opened to gain access to the contents of the storage bag), are engineered to provide bond strength greater than 5 6N/25mm. Sealing is achieved by applying a heat bar (see Figure 3) having a temperature of say 2000C to those edges to be sealed. In contrast, the auxiliary seal is also formed by application of a heat bar, but having a lower temperature of say 180"C to provide reduced bond strength of around 3 to 4 NM/25mm. Referring now to Figures 3 and 4, the seal bar system is designed to apply 10 heat to particular areas and prevent heat from being applied to others. Referring to Figure 3, a heat seal bar is heated to the necessary temperature to form the secondary or top header seal shown in Figure 2 at the same time as the auxiliary seal shown in Figures 1 and 2. The auxiliary seal has reduced bond strength when compared to the bond strength of the bottom and side seals. The secondary seal 15 may also have reduced bond strength when compared to the bond strength of the bottom and side seals. Now referring to Figure 4, a cool seal bar shown is applied to cool the formed seals whilst protecting the zipper-style seal. While the invention has been described in conjunction with a limited number of embodiments, it will be appreciated by those skilled in the art that many alternative, 20 modifications and variations in light of the foregoing description are possible. Accordingly, the present invention is intended to embrace all such alternative, modifications and variations as may fall within the spirit and scope of the invention as disclosed. 0425