GB2415684A

GB2415684A - Bags of easy closure and tear open construction

Info

Publication number: GB2415684A
Application number: GB0414658A
Authority: GB
Inventors: Paul Stuart Brassington; Patrick Thomas Connelly; John Joseph Dermot Griffiths; I J Smith
Original assignee: Flexipol Packaging Ltd
Current assignee: Flexipol Packaging Ltd
Priority date: 2004-06-30
Filing date: 2004-06-30
Publication date: 2006-01-04
Anticipated expiration: 2024-06-30
Also published as: GB0414658D0; GB2415684B

Abstract

A plastic bag comprises a flat stable base 908 and first and second wall portions. The base and wall portions form a bag or approximately rectangular section when containing product. The bag further comprises a closure flap. One or both of the closure flap and the front face of the bag have a line of adhesive 913. In use, the front face is folded down onto the product contained in the bag, and the closure flap is folded over on top of the front face and so that side portions of the closure flap contact side walls of the bag. The line of adhesive secures the closure flap in this closed position. The closure flap is provided with a line of weakness 914 which is breached to gain access to the contents of the bag. The base is gusseted.

Description

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BAGS OF EASY OPEN AND CLOSURE CONSTRUCTION

The present invention relates to bags or sacks, and in particular to plastic bags or sacks having an improved easily openable construction. The invention relates additionally to such bags or sacks which are able to stand stably and unsupported.

The bags of the present invention may be of any suitable size from relatively small (e.g. about litre capacity or less) to large sacks. A primary use of the bags of the invention is in industrial processing of products within and between factory premises, such as for transporting part finished products within and between factory premises and to retail premises. In particular, the bags of the invention are useful for carrying products, such as frozen meat portions, within the food processing industry. The bags of the invention may also be suitable for use as external packaging for certain solid (e.g powder or granular) consumer products (such as detergents).

Plastic bags of many different types are known, but one particular problem has been in providing bags which incorporate an easily openable closure and which are easily and relatively cheaply manufactured, easy and reliable to use and, for some uses, suitable for containing relatively heavy materials. A particular problem in relation to the food industry is to provide bags which can be opened and closed without the risk of contaminating the food with, for example, shards of plastic or pieces of paper or string used in the bag.

The present invention relates to a bag or sack which has a closure capable of meeting the aforementioned requirements. The present invention further relates to a bag which is additionally capable of standing upright and in a stable manner on a surface, when both containing and not containing a product, preferably when containing product which may, in particular uses, be a relatively heavy solid product.

4 8, , 4 4 According to a first aspect of the present invention there is provided a plastic bag having an opening end and a closed base portion on which the bag may stably stand when containing product, the bag comprising: front and rear wall panels, attached to one another at their respective side edges; a mouth through which the bag may be filled with product defined between an upper edge of said front wall panel and said rear wall panel; a closure flap, coextensive with the width of, and depending from, said rear wall panel; said base portion comprising, in a first configuration, a base panel connected along opposing sides thereof to the respective front and rear wall panels by means of first folds, said panel further having a second fold co-extensive with the width of said wall panels and substantially parallel to said first folds, said second fold dividing the base panel into first and second panel leaves such that the second fold and the panel leaves lie between the wall panels with the external faces of the panel leaves towards each other; and a joining line extending from each end of said second fold to each first fold, along which joining lines the front and rear side walls are respectively joined to the base panel one or both of said closure flap and said front face of said front wall comprising an adhesive region by means of which the closure flap may be attached to the front face of the front wall panel, said closure flap further comprising a line of weakness along which the closure flap may be torn after attachment of the closure flap to the front wall panel to expose the interior of the bag.

According to a second aspect of the invention there is provided a plastic bag having an opening end and a closed base portion on which the bag may stably stand when containing product, the bag comprising: front and rear wall panels, attached to one another at their respective side edges, and together defining, at least in a lower portion of said bag, front and rear side walls and first and second end walls of the bag; a mouth through which the bag may be filled with product defined between an upper edge of said front wall panel and said rear wall panel; a closure flap coextensive with the width of, and depending from, said rear wall panel; said base portion comprising, in a second configuration, a generally rectangular base panel portion having opposed side edges and opposed end edges and generally triangular end wall portions each depending along a base side thereof from respective end edges of the base panel portion said base panel portion being connected to the respective front and rear side walls by means of first folds coincident with said respective side edges, said triangular end wall portions having an apex positioned above said base panel and having side edges defined by said joining lines extending between said apex and respective corners of said base panel portion whereby the first and second end walls are joined to said triangular end wall portions; one or both of said closure flap and said front face of the front wall panel comprising an adhesive region by means of which the closure flap may be attached to the front face of the front wall panel and said closure flap further comprising a line of weakness along which the closure flap may be torn after attachment of the closure flap to the front wall panel to expose the interior of the bag.

Preferbly said adhesive region is formed proximate an upper end portion of said closure flap.

According to a third aspect of the invention there is provided a plastic bag having an opening end and a closed base portion on which the bag may stably stand when containing product, the bag comprising: front and rear wall panels, attached to one another at their respective side edges, and together defining front and rear side walls and first and second end walls of the bag; a closure flap, coextensive with and depending from said rear wall panel; said base portion comprising, in a said second configuration, a generally rectangular base panel portion having opposed side edges and opposed end edges and generally triangular end wall portions each depending along a base side thereof from respective end edges of the base panel portion said base panel portion being connected to the respective front and rear side walls by means of first folds s: .e s' coincident with said respective side edges, said triangular end wall portions having an apex positioned above said base panel and having side edges defined by said joining lines extending between said apex and respective corners of said base panel portion whereby the first and second end walls are joined to said triangular end wall portions; a product within the bag for transport or storage; an upper part of said front wall being folded inwardly to lie over an upper surface of the product within the bag; one of said front face of the front wall panel and said closure flap comprising an adhesive region by means of which a middle portion of the closure flap is attached to the front face of the front wall panel and side end portions of the closure flap are attached to respective end walls, and said closure flap further comprising a line of weakness along which the closure flap may be torn to expose the interior of the bag.

Preferably said line of weakness is a substantially straight line extending substantially across the whole width of the closure flap.

Preferably the line of weakness is a perforation in the closure flap.

Preferably the joining lines are heat welds.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will be made (by way of example only) to the following drawings, in which: Figure 1 is a schematic plan of a bag according to the present invention in a flat condition, as manufactured and prior to filling.

Figure 2 is a section along the line A-A of Figure 1.

Figure 3 is a view of a part of a bag according to Figure 1 in an open or expanded condition ready for filling with product.

Referring now in particular to Figures 1 and 2, the bag 901 comprises a mouth 902, a base portion 903, front and rear wall panels 904A, 904B, and first and second side edges 905a, 905b. Front and rear panels 904A,B are joined at first and second edges 905a, 905b along their entire length, by suitable means such as heat welding and/or adhesive and preferably by heat welding. However, in alternative constructions, the joins may be located elsewhere than the side edges, or, where the body of the bags is produced in the form of a tube, may be absent.

A closure flap 912 extends from rear wall panel 904B and is preferably formed integrally therewith. The closure flap has nominally (or exactly) the same width as the rear wall panel 904B and includes, towards its upper (as illustrated) edge a line of adhesive 913. In the open condition of the bag prior to filling with contents, the line of adhesive 913 may be covered with a removable release paper or the like.

The line of adhesive may alternatively be provided on the front wall panel. The closure flap 912 is also provided with a line of weakness 914 extending substantially across its whole width. Line of weakness 914 is preferably a perforation.

The base panel 903 comprises a tuck defined by first folds 909' and 909" and second fold 990. The tuck has panel leaves or tuck leaves 906a and 906b each having two mitred joins 907. Mitred joins 907 are seal lines (preferably comprise heat welds) extending from each end of the second fold 990 (that is, at point X) to the first folds 909', 909" at points Y by which the panel leaves 906a,b are joined to the adjacent wall panel 904A,B. For the avoidance of doubt, the mitred joins 907 do not join the respective panel leaves 906a,b to one another. The mitred joins 907 thus form internal corner boundary edges of the bag. As can best be seen in Figure 2, second fold 990 and panel leaves 906a, 906b lie between the wall panels 904A,B with the external faces of the panel leaves 906a, 906b towards each other.

Figure 3 illustrates the bag in a substantially fully open condition containing, or ready to receive, a product. Front and rear wall panels 904A and 904B no longer lie substantially flat against each other as in Figures 1 and 2, but are spaced apart from one another. The front and rear wall panels 904A, 904B are joined to each e' e': ler:: . other along side edges 905a and 905b by means of seal lines which preferably comprise heat welds along the whole length of side edges 905a, 905b. Other joining means such as adhesive may additionally or alternatively be used.

A substantially rectangular base part 908 (which is formed from the base portion 903), on which the bag may rest in an upright position, is defined by fold lines 909', 909" and 910', 910" and is formed by opening out panel leaves 906a, 906b. Mitred joins 907 now lie above a horizontal plane, preferably tending towards a vertical plane, although filling of the bag may cause the mitred joins 907 to be displaced somewhat from the vertical. Mitred joins 907 and fold lines 910', 910" define upstanding generally triangular end wall portions 911a, 911b. Fold lines 910', 910" form the base side of portions 911a, 911b and mitred joins 907 form the remaining sides with the apex of the triangles at points X. Thus, in the embodiment illustrated the apex of the triangular end wall portions 911a, 911b lies above the base portion 908 in use. Portions 911a, 911b are formed by an opening out of the panel leaves 906a, 906b and comprise end regions of the base panel 903. Preferably, the mitred joins 907 form an angle of between 30 and 60 with respect to the fold lines 910', 910". Additional reinforcements (such as reinforcement welds or adhered reinforcement patches) may be provided where desired such as at points X where the welds of mitred joins 907 meet the seal lines 905a, 905b.

The rectangular base part 908 determines the shape of at least a lower part of the bag 901 in the expanded condition in that the wall panels 904A,B define front and rear side walls 904A', 904B' and first and second end walls 904A'' and 904B''.

The distinction between the front and rear walls 904A', 904B' and end walls 904A' ', 904B' ' becomes less apparent towards the upper part of the bag 901.

The width of the closure flap 912 measured between points F-F (Figure 3) is greater than the width of the front side wall 904A' measured between points Y-Y. Thus in use of the bag 901 it is filled with product to a level below the top edge of the front side wall 904A'. The front side wall 904A' is then folded inwardly so that part of its inner face lies on the upper surface of the product, as indicated by arrow C. The closure flap can then be folded forwards, as indicated by arrow D so that the inner , , , ' 1 |e::: c.. .' ..

face of the closure flap 912 is juxtaposed with the outer face of the front side wall 904A'. The adhesive line 913 thus adheres the closure flap 912 to the outer face of the front side wall 904A'. Because the width of the closure flap F-F is greater than the width of the front face 904A', side edge parts of the closure flap 912 are able to adhere, by means of adhesive 913, to parts of the end walls 904A'' and 904B'' respectively. To open the bag 901 in order to gain access to the produ* within, it is necessary only to tear the closure flap 912 along the line of weakness 914.

Thus, the invention provides a bag which has an easily closeable flap for sealing the contents of the bag, the flap being attachable to the front panel and/or the side walls of the bag, in use. Additionally, the invention provides a bag can that stand stably in an upright position, which is suitable for carrying heavy and bulky materials, which is simple and cost effective to manufacture in an automated process and which provides excellent palletisation properties. l

Claims

i:. .. :: . . CLAIMS

1. A plastic bag having an opening end and a closed base portion on which the bag may stably stand when containing product, the bag comprising: front and rear wall panels, attached to one another at their respective side edges; a mouth through which the bag may be filled with product defined between an upper edge of said front wall panel and said rear wall panel; a closure flap, coextensive with the width of, and depending from, said rear wall panel; said base portion comprising, in a first configuration, a base panel connected along opposing sides thereof to the respective front and rear wall panels by means of first folds, said panel further having a second fold co-extensive with the width of said wall panels and substantially parallel to said first folds, said second fold dividing the base panel into first and second panel leaves such that the second fold and the panel leaves lie between the wall panels with the external faces of the panel leaves towards each other; and a joining line extending from each end of said second fold to each first fold, along which joining lines the front and rear side walls are respectively joined to the base panel one or both of said closure flap and said front face of the front wall panel comprising an adhesive region proximate an upper end portion thereof by means of which the closure flap may be attached to the front face of the front wall panel and said closure flap further comprising a line of weakness along which the closure flap may be torn after attachment of the closure flap to the front wall panel to expose the interior of the bag.

2. A plastic bag having an opening end and a closed base portion on which the bag may stably stand when containing product, the bag comprising: front and rear wall panels, attached to one another at their respective side edges, and together defining, at least in a lower portion of said bag, front and rear side walls and first and second end walls of the bag; l l : I' leec.' a mouth through which the bag may be filled with product defined between an upper edge of said front wall panel and said rear wall panel; a closure flap coextensive with the width of, and depending from, said rear wall panel; said base portion comprising, a generally rectangular base panel portion having opposed side edges and opposed end edges and generally triangular end wall portions each depending along a base side thereof from respective end edges of the base panel portion said base panel portion being connected to the respective front and rear side walls by means of first folds coincident with said respective side edges, said triangular end wall portions having an apex positioned above said base panel and having side edges defined by said joining lines extending between said apex and respective corners of said base panel portion whereby the first and second end walls are joined to said triangular end wall portions; one or both of said closure flap and said front face of the front wall panel comprising an adhesive region proximate an upper end portion thereof by means of which the closure flap may be attached to the front face of the front wall panel and said closure flap further comprising a line of weakness along which the closure flap may be torn after attachment of the closure flap to the front wall panel to expose the interior of the bag.

3. A plastic bag having an opening end and a closed base portion on which the bag may stably stand when containing product, the bag comprising: front and rear wall panels, attached to one another at their respective side edges, and together defining front and rear side walls and first and second end walls of the bag; a closure flap, coextensive with and depending from said rear wall panel; said base portion comprising, a generally rectangular base panel portion having opposed side edges and opposed end edges and generally triangular end wall portions each depending along a base side thereof from respective end edges of the base panel portion said base panel portion being connected to the respective front and rear side walls by means of first folds coincident with said respective side edges, said triangular end wall portions having an apex l l t t t' t' positioned above said base panel and having side edges defined by said joining lines extending between said apex and respective corners of said base panel portion whereby the first and second end walls are joined to said triangular end wall portions; a product within the bag for transport or storage; an upper part of said front wall being folded inwardly to lie over an upper surface of the product within the bag; one or both of said closure flap and said front face of the front wall panel comprising an adhesive region proximate an upper end portion thereof by means of which a middle portion of the closure flap is attached to the front face of the front wall panel and side end portions of the closure flap are attached to respective end walls, and said closure flap further comprising a line of weakness along which the closure flap may be torn to expose the interior of the bag.

4. A bag as claimed in any preceding claim wherein said line of weakness is a substantially straight line extending substantially across the whole width of the closure flap.

5. A bag as claimed in any preceding claim wherein the line of weakness is a perforation in the closure flap.

6. A bag as claimed in any preceding claim wherein the joining lines are heat welds.