ES2288316T3 - EASY OPENING STRUCTURE BAG. - Google Patents

Abstract

A plastic bag (500) for transporting and storing bulk powder or granular material or bulk food ingredients, the bag (500) has an open end and a closed end (508) and comprises: a first and a second side wall ( 501, 502) which together form a bag part (500A) having front and rear faces; a mouth (521) to access the inside of the bag (500) during use; a closing flap (505) that covers and closes the mouth and that includes a region (515) that is detachably attached to the front face so that at least a part of the closing flap (505) can be detached from the front face through the region (515) detachably joined to expose the mouth (521), the frontal face remaining functionally intact; characterized in that: the closing flap (505) is formed separately from the first and the second side wall (501, 502) and the mouth (521) is different from the open end; the detachably bonded region comprises at least one area of adhesive that extends from one side edge of the closure flap to the other without interruption whereby the mouth is sealed, not allowing the contents of the bag to exit; and because the bag (500) further comprises: a region (550) that can be closed adjacent to the open end of the bag and other than the mouth (521) and the part of the closing flap that can be detached in said region (550) that the open end of the bag can be closed can be closed by the user by thermal sealing, after the contents have been inserted into the bag through the open end, the thermally sealable faces are exempt from any adhesive .

Description

Bag with easy opening structure.

The present invention relates to bags or bags and in particular bags or plastic bags that have a Improved construction and that can be easily opened. The invention further refers to said bags or sacks that are capable to stand stably and without help.

The bags of the present invention can be of any suitable size from relatively small bags (for example approximately one liter or less capacity) up to large bags and are very useful for, for example, uses of industrial processing within and between facilities industrial and for the transport of food products between Factory facilities and retail, more specifically in the food processing industry. The bags of the invention may be suitable as an outer container of certain solid and liquid consumer products, such as detergents The bags can also find application in home supply services, especially when sometimes It is necessary to return products by mail to the supplier.

Plastic bags of many types are known different, but a particular problem has been to provide bags that incorporate an easy opening closure and are easy and relatively cheap to manufacture, easy and reliable to use, and, for some uses, suitable for containing materials relatively heavy The present invention seeks to provide a bag that has a closure capable of satisfying these requirements. The The present invention also seeks to provide a bag that is additionally capable of standing upright vertically stable on a surface, especially while containing a product that, in particular uses, can be a product relatively heavy

The bags of the present invention are particularly suitable for containing bulk products in form of powder, granules or liquids. Examples of such products include bulk chemicals and bulk ingredients such as used in food for humans and animals and in products household such as washing powders and washing liquids; foods such as partially prepared foods prepared; household products and garden products such as peat or fertilizer. In the food industry, bags and sacks of plastics are especially used in the transport of food, ingredients or food products partially prepared around or between facilities. In the context of This technical report, bulk products may include retail products such as liquid detergents and solids, dry foods, food ingredients and foods preparations for which the bags of the invention can form The outer container. The quantity of bulk product for which the bag is adapted will vary with the particular use and, for example, For prepared foods, the amount may not be very large.

The present invention also relates to bags or sacks, and in particular plastic bags or sacks, which they are able to stand stably on a surface when they contain a solid or liquid product including in particular a relatively heavy product.

Document DE U 90 03 401.5 describes a package for hygienic items comprising opposite walls and a detachable closure flap covering a mouth to dispense articles.

Document DE U 297 19 685 describes a package to contain tea bags that includes a closing flap that It can be closed again.

WO 98/18674 describes bags for Contain a granular product that includes a flat base.

Consequently, the present invention supplies in a first aspect a plastic bag for transport and store bulk materials in powdery or granular or bulk food ingredients, the bag has a open end and a closed end and comprises:

a first and a second side wall that form a part of a bag that It has front and back faces;

a mouth for him access to the inside of the bag during use;

a flap of closure that covers and closes the mouth and that includes a region that is detachably attached to the front face so that at least a part of the closing flap can be separated from the face frontal through the detachably attached region to leave the view of the mouth, the front face remaining functionally intact;

       \ vskip1.000000 \ baselineskip
    

which is characterized because:

the flap of closure is formed separately from the first and second side wall and mouth is different from the open end;

the region detachably bonded comprises at least one area of adhesive that is extends from a side edge of the closing flap to the another without interruption to seal the mouth to avoid the exit of the contents

       \ vskip1.000000 \ baselineskip
    

and because the bag also includes:

a region that can be closed, arranged adjacent to the open end of the bag and other than the mouth and the part of the closing flap that can peel off and in that region that can be closed, the open end of the bag can be closed by the user by sealing thermal after the contents have been entered into of the bag through the open end, thermally faces Sealants are free of any type of adhesive.

A second alternative aspect of the invention supplies a plastic bag to transport and store powdery or granular bulk materials or ingredients bulk food, the bag has an open end and a closed end and comprises:

a first and a second side wall that form a part of a bag that It has front and back faces;

a mouth for him access to the inside of the bag during use;

a flap of closure that covers and closes the mouth;

       \ vskip1.000000 \ baselineskip
    

which is characterized because:

the mouth is other than the open end;

the flap of closure is formed separately from the first and second side wall and includes a region comprising at least one area of adhesive per middle of which the closing flap is attached to the front face and extending from a side edge of the closing flap to the other without interruption to seal the mouth thus avoiding the exit of the contents of the bag, the closure flap includes at least one weakened line that defines a part of the flap that does not include no part of the region that is attached to the front face and said part can be opened by tearing along the weakened line to leave the mouth of the bag in sight;

       \ vskip1.000000 \ baselineskip
    

and because the bag also includes:

a region that it can be closed arranged adjacent to the open end of the bag and other than the mouth and the part of the flap that can be opened by tearing, by means of said region that the open end of the bag can be closed by the user thermally sealing it after the contained inside the bag through the open end, the faces thermally sealable are free of any kind of adhesive.

In a preferred embodiment of these aspects of the invention, the first side wall forms the front of the bag, the second side wall forms the back of the bag, the side walls have substantially the same length, the mouth comprises a groove formed on the front face and the region that can be closed includes the parts of the end of the first and of The second side wall.

In a variant of this embodiment, the face front includes an additional weakened line that can be broken to form the mouth

In preferred arrangements, the region that can closing also includes an end portion of the flap of the closing.

Thus, the region that can be closed can include end portions of the first and second side wall. These end portions can, for example, be heat sealed to Close the bag after filling. In some constructions the region that can be closed can also include a part of the end of the closing flap, which can then also be part of thermal sealing (or other closing means).

In another preferred embodiment of these aspects of the invention, the first side wall forms the front of the bag, the second side wall forms the back of the bag, the second side wall has an extension beyond the part of bag, the closing flap covers a part of the first wall lateral and the extension of the second lateral wall, and the region that can be closed includes the extension of the second side wall and a part of the end of the closing flap.

       \ newpage
    

Preferably, in this embodiment, the mouth is defined by the edge of the end of the first side wall and the mentioned edge of the end is visible when the flap closing takes off, allowing access to the inside the bag.

In another variant, the bag according to the invention, further comprises a second flap that hangs by means of a crease of the edge of the mouth and extending towards the inside the bag. The second flap can optionally be attached by means of adhesive to the inner face of the second wall side. Desirably, said adhesive is an adhesive detachable

It is also preferred, according to the first aspect of the invention, that a tour along the first lateral wall, and substantially parallel and adjacent to the mouth rest entirely in a detachably linked area, at less within the separable part of the closing flap. This construction ensures that there is an uninterrupted seal (through of the detachable adhesive) across the full width of the detachable region so that, for example, there is no path through which the powder or liquid product can escape through of easy opening closure.

During the use of the bags of the invention is advantageous for the bags to be able to stand stably and no support during and after filling. Consequently, a most preferred embodiment of the invention provides the characteristic that the bag also comprises a base part on which the bag can be held stably When it contains a product.

Preferably the base part understands:

a base panel connected along its opposite sides with the respective first and second side walls by means of first folds, said panel also has a second fold, coextensive with the width of said walls and substantially parallel to said first folds, said second fold divides the panel of base on a first and a second sheet, so that the second fold and panel sheets rest between said walls sides with the outer faces of the panel sheets looking at each other each; Y

together chamfered seals comprising a sealing line that extends from each end from said second fold to each first fold, along said sealing lines the first and the second side wall are joined respectively with the panel of base.

Chamfer seals form corners in chamfer that can be removed if necessary to improve the palletizing the bags, but this is not essential. That is to say, it may be necessary that the bags of the present embodiment be suitable for transport on a pallet and to hold the bags on the pallet, a number of bags that form a pallet load to they are often packed by contraction of a plastic film (or packed in another way) on the pallet. In the technique bags anterior (without a stable flat base), in the absence of joints airtight in chamfer, the product contained in the bag is capable of fill the bag exactly to the corners. This makes the corners are hard and pointed so that the corners tend to cut or tear the packaging by contraction and / or the adjacent bags. These prior art bags (without the flat base construction according to the present embodiment) they include chamfered seals in the corners, to avoid that the product passes exactly inside the corners. From this way, the corners, although still pointed, are flexible and are less likely to cause damage. At the moment realization the chamfer seals are an integral part of stable flat base formation, but they can also serve to contribute to the flexibility of the corners for a Better palletizing Eliminating the corners in chamfer you can provide additional improvement in palletizing, but it is not essential. Similarly, when the bags of this embodiment form external packaging of consumer products, corners in chamfer can be removed to avoid sharp corners that do not are suitable for the consumer and to allow the bags can be stacked more easily on store shelves and supermarkets

In an alternative definition, the base part comprises a generally rectangular base panel having opposite side edges and opposite end edges and generally parts of triangular end walls each of which hangs along one of its sides of the base of a respective end edge of the base panel, said base panel is connected to the respective first and second side walls by means of first folds coinciding with said respective side edges, said triangular parts of the end wall have a vertex located during use above said base panel and have side edges comprising sealing lines extending from said vertex and from the respective corners of said base part along which the first and second respectively join side wall with said parts of the wall of the
extreme.

Both in the initial construction and in the Last, the base panel is preferably, but not essentially, formed integrally with the first walls lateral.

Both in the initial construction and in the last according to this embodiment, preferably the lines sealing (of the seals in chamfer) comprise a heat seal

Desirably, the seal line of the joints chamfer seals (as defined in the initial construction) it forms an angle between 30º and 60º with respect to the second fold and more specifically the sealing line of the seals in chamfer forms an angle of 45º with respect to the second fold.

In constructions of the bag in which it is not requires a stable base, the bag can be built so that can also be opened at one end of the bag, so separated from the easy opening closure and the region that can be close. In this construction the closed end of the bag is supplied by a third flap that overlaps and is attached detachably to the first or second side wall, said third flap hangs on the second or first wall side at the end of the bag away from the open end.

According to the second aspect of the invention, it is preferred that the closure flap includes at least two weakened line along which said part can be opened by tearing.

According to the first aspect of the invention, preferably the part of the closing flap that can  being detached is defined by at least one line delimited to along which the closing flap is torn to leave the discovered the mouth of the bag.

Preferably the part of the closing flap that can take off is defined by two weakened lines. Preferably the weakened lines extend from an edge from the end of the closing flap separated from the region that can close to points near the mouth.

Preferably, the weakened line or lines they are perforations formed in the closing flap. Alternatively,  weakened lines may comprise lines in which the closure flap material is thinner, or dotted lines in The material of the closing flap.

In another variant, the weakened lines end in one or more finger holes formed in the flap closure, by means of which the flap can be grasped to tear. This construction facilitates the opening of the bag.

In an additional variant of the first or second aspect of the invention, the closure flap includes a weakened arc-shaped line that extends from points on the closing flap near the mouth towards an edge of the end of the closing flap.

In this case, to facilitate the opening of the bag, the bag preferably includes at least one hole for the finger formed in the closing flap on the previous line weakened by means of which the closing flap can be grasped for its torn. Alternatively, a tongue can be attached in a similar point, said tongue can be grasped with the fingers to Start tearing. An adhesive line can be arranged permanent between the edge of the end of the closing flap and in the weakened line or lines to help hold the flap of Close before opening the bag.

Other possible line constructions Weakened and flap closure include the following:

the lines weakened can be substantially straight and substantially parallel to the edges of the bag; or

the ends of weakened lines at the edge of the flap end of closure are more separated than the ends of the lines weakened near the mouth; or

the ends of weakened lines at the edge of the flap end of closure are so separate that they define a finger tab by means of which the closing flap can be grasped for torn I

the flap of closure is sealed on the front face along parts of the edge of the end extending from the respective lines weakened to the sides of the bag.

In a particularly preferred construction the line or weakened lines has a form such that the part of the closing flap defined by them takes the form of a dispensing nozzle when torn along the line or of the weakened lines.

According to the first aspect of the invention, preferably apart from the closing flap that can peel off is attached to the front face by means of an adhesive detachable A hot melt adhesive is particularly suitable. Alternatively, the part of the closing flap that can take off can be attached to the front face by means of a detachable region thermally sealed or sealed by hot.

The plastic bag according to the invention it comprises a region that can be closed formed next to the end opening the bag to close the bag after filling. This construction allows the bag to be filled from it end of the easy opening part and that end be sealed after filling. Also, in this way others can be formed advantageous constructions at the other end of the bag, especially constructions that will not allow the filling of the bag from that other end. The closing region can be closed by any suitable means. Examples of suitable means for close the region that can be closed include thermal sealing, adhesive (for example an initially coated adhesive layer by a detachable protective tape) and closing means by pressure such as those that extend along the width of the region that can be closed and comprising a male component on one side and a female component on the other side, said components fit together to form a closure.

Handles can be formed to carry the bag in or near (for example, just above) the region that can close, in ways such as cutting, punching or forming suitable holes in any other way in the first and second side walls, in extension to the second wall side or on the closure flap (as appropriate for the particular construction). Alternatively, handles can be attached separated to the region that can be closed or near it.

To better understand the invention, and to show how it can be done, reference will be made (only by way of example) to the following drawings, in which:

Figure 1 is a schematic view in perspective of a bag according to a variant of the invention.

Figure 2 is a sectional view along of line A-A in figure 1.

Figure 3 is a schematic plan view of a bag according to another variant of the invention that illustrates a weakened line on the closing flap.

Figure 4 is a schematic plan view of a bag according to another variant of the invention that Illustrates two weakened lines on the closing flap.

Figure 5 is a schematic plan view of a bag according to another variant of the invention.

Figure 6 is a schematic plan view of a bag according to another variant of the invention.

Figure 7 is a section along the D-D line of figure 6.

Figure 8 is a section along the line B-B in figure 6.

Figure 9 is a plan view of the bag of Figure 5 in an open condition.

Figure 10 is a plan view of the bag of Figure 10 in an open condition.

Figure 11 is a schematic plan view of a bag according to another variant of the invention that can seal at both ends.

Figure 12 is a sectional view along of the E-E line in figure 11.

Figure 13 is a schematic plan view from a bag according to another additional variant of the invention.

Figure 14 is a section along the line A-A in figure 13.

Figure 15 is a part of a bag of according to figure 13 in an open condition.

Figure 16 is a schematic plan view of a bag according to the invention incorporating the construction of the base of figures 13 to 15.

Figure 17a is a section along the F-F line of figure 16.

Figures 17b and 17c illustrate variations of the bag of figures 16 and 17a.

Figure 18 is a schematic plan view of a bag according to the construction invention similar to the bag in figure 16.

Figures 19 to 22 illustrate procedures for manufacture the bags according to the invention.

Figure 23 is a schematic plan view of a bag according to the invention in which the mouth is not adjacent to one end of the bag.

Figure 24 illustrates a procedure of manufacture of the bag in figure 23.

       \ newpage
    

In this application, unless indicated otherwise, or unless the context requires otherwise, the bags of the invention are described and defined in relation to its flat position before filling, that is, the bags are describe and are defined in a configuration in which the walls lateral ones rest flat against each other without forming substantially empty spaces between them. Clearly, as that the bag is filled with product, the side walls of the bag are separated and the configuration of the bag changes.

Figures 1 to 12 illustrate bags of one construction in which the base part is not required for its stable hold In these figures, the bag 200 comprises a part 200th bag and a flap 205 closure. The 200th part of stock market it is formed with a first side wall 201 and a second wall side 202. Walls 201 and 202 face each other in what respect that they rest on each other and in these embodiments the side walls 201, 202 have the same length. The walls 201, 202 are joined together along their side edges 203, 204, for example, by thermal sealing (thermal sealing a the sides of the side edges 203, and 204 are not illustrated specifically for clarity). In a configuration alternatively, the walls of the part of the bag can be formed as tubes so that there is no joint or seal different along from its sides

The closing flap 205 overlaps a end region of the first side wall 201 and in these embodiments hangs on the second side wall 202 at the edge 206 of the limit of the second side wall 202. The closing flap 205 can be attached to the second side wall by means of a joint airtight but in these embodiments preferably the flap 205 closure is formed integrally with the second side wall 202 and hangs on the second side wall 202 by means of a fold 207. It can be seen that the fold 207 is adjacent and substantially parallel to the edge 209 of the end of the first side wall 201. (In Figures 2, 7, 8 and 12, the separation between the first wall side 201 and the second side wall 202 and the flap 205 of closure is exaggerated for clarity). The edge 209 of the end defines the mouth of the bag 200 when the bag is open. A optional second flap 208 extending inside the interior 211 of the bag 200 joins the edge 209 of the limit of the end of the first side wall (i.e. at the edge of the mouth limit) by means of a fold 210 of the limit. The edge 202 of the end of the second flap 208 is illustrated by a dotted line in the Figures 5 and 6.

The closing flap 205 adheres to the first side wall 201 by means of one or more connecting regions 205 detachable The detachable junction region 215 may take a variety of shapes but preferably comprises an adhesive detachable and more preferably a hot melt adhesive. The detachable adhesive can be applied to any surface of the first side wall 201 or to the surface of the flap 205 of close, or both. Other examples of removable adhesives may include a pressure sensitive adhesive comprising two non-sticky components, the first of which is applied on the closing flap and the second one is applied to the first wall side. When the two components come together and pressure is applied, an adhesive bond is formed. Alternatively, the adhesive detachable can be a permanent or non-permanent adhesive or solvent adhesive applied to any surface of the first side wall 201 or to the surface of the closing flap 205 or to both.

The region or regions of detachable adhesive 215 They can have a number of different suitable forms. For example, region 215 can occupy the entire area of the first wall side 201 resting below the closure flap 205 or only part of that region. Adhesive regions detachable can be in the form of bands or stripes that extend laterally through the first side wall or that extend diagonally or in curved paths (similar to waves). The regions of detachable adhesives can be flashing along the first side wall.

It is preferred that the adhesive region or regions detachable are such that it is not possible to trace a path to along the surface of the first side 201 from its edge limit 209 from the end (i.e. from the mouth) to the edge of the closing flap 213 (ie the most separated edge of the mouth), said path does not cross a region of detachable adhesive. Where, as described further below, only take off a part of the closing flap, the trajectory before This can only be applied to that part.

It is particularly preferred that a region Continuous peel off adhesive is disposed substantially parallel and adjacent to edge 209 of the limit of the end of the first wall 201 (i.e. adjacent to the mouth), as it can particularly seen in figure 5. This construction helps ensure the integrity of the closure.

The region or regions of detachable adhesive 215 they can also be selected to be resealable, so that the bag can be closed again after opening middle of the region or regions of removable adhesive 215.

For example, adhesive transfer permanent or non-permanent, hot melt adhesive or solvent applied to any surface of the first wall side 201 or to the surface of the closure flap 205 or both, it can also occur when the bag is opened allowing so The bag can be resealed.

Alternative constructions of the region detachable 215 also include specific adhesives whose Adhesive properties vary according to temperature surrounding, thus allowing the bags to be used in extreme temperatures. In some cases, these adhesives can be Not detachable at room temperature.

Alternative constructions for region 215 Detachable bond also include the use of adhesives that are frangibles

Alternative constructions of region 215 of detachable junction include heat-welded detachable regions and thermally sealed. To supply a thermal weld or a detachable thermal seal, it may be necessary to weaken in some measure the resistance of welding or sealing. This can achieved by interposing some kind of contaminant between materials to be welded or sealed. The contaminant can be selected among a wide variety of materials, but suitable examples they include inks and lacquers or a third layer of film that weld to layers of material with less force than materials soldiers with each other.

Now with specific reference to figures 1 and 2, the illustrated bag can be opened simply by taking off the closure flap 205 through the joining regions 215 detachable to expose the mouth 221. In this and in others embodiments of the invention, in which adhesive is used detachable, the adhesive is selected so that its strength Cohesive is less than the strength of the adhesive. So, in the embodiment of figures 1 and 2, as the flap is grasped closing at its leading edge 213 and pulling it off, it detaches from the first side wall 201 in the detachable region 215 without being cause substantial damage to the closure flap 205 or to the first side wall 201. Thus, neither the closing flap 205 nor the first side wall 201 is torn and although each of them may be somewhat twisted, no distortion of the first side wall 201 is significant in terms functional.

In this and other embodiments, the second flap optional 208 helps maintain closure integrity when the 200 bag is filled with its contents. The second flap 208 is effective to prevent the contents of the bag from penetrating up to an excessive extension between the first side wall 201 and the closure flap 205 around the region of the first fold 207, that could otherwise cause distortion of the wall side 201 and / or the closure flap 205 so that they could peel off in the detachable region 215. The closure of the bag it could then crack allowing content to leak or It spills.

In particularly preferred variations of the invention, the closing flap 205 is provided with one or more weakened lines along which the closing flap 205 can be torn to open the bag and expose its inside. The weakened lines preferably have the form of perforations in flap 205 closure.

With reference to figures 3 and 4, it is illustrated a bag that incorporates only a weakened line. The line weakened 216 has the shape of an arc that extends from the W-W points near the mouth and the first fold 207 through region 215 of detachable clamping towards the edge 213 of the closure flap 205. The weakened line 216 defines a part 219 of the closing flap that can be grasped and detached by tearing along weakened line 216 to open the bag. Preferably, the ends of the weakened line 216 do not extend beyond detachable region 215 towards the mouth to preserve the integrity of the closure and prevent the escape of product.

To facilitate the opening of the bag, the embodiment illustrated in figure 4 includes a hole 250 for the finger by means of which the flap 205 of close to start tearing along the weakened line 216. Alternatively, a tongue can be attached at a point similarly, said tongue can be grasped with the fingers to start the torn. As indicated in Figure 4, a permanent adhesive line 240 between the edge 213 of the end of the closing flap and the weakened line or lines 216 to help to the fastener of the closing flap 205 before the opening of the 200 bag.

In an alternative embodiment of the invention a the one illustrated in figure 4 may be desirable to refrain from use of adhesive in the region of the closing flap defined by the weakened line 216. In this case, the closing flap 205 must sealed with the first side wall 201 (such as by non-detachable adhesive or thermal seal) in the area outside the part 219, to supply the necessary closure. For example this can be achieved by means of permanent adhesive line 240 and hermetic seals on side edges 205A, 205B.

Now with reference to figures 5 to 10, illustrate variations of the bags of the invention in which the bags include two weakened lines 216A, 216B that define a part 219 of the closing flap that can be detached at along the weakened lines to open the bag. I also know illustrate additional features that can be incorporated into other embodiments of the invention. In this regard, flap 205 closure can be sealed with the first side wall 201 in its edge 213 of the end by means of seals 212A, 212B (figure 6) and on its side edges 205A, 205B (figure 5), but All this is not essential. The 212A and 212B seals are preferably thermal seals, however, can also use adhesive seals, using permanent adhesive or not permanent. Airtight joints 217 can be formed in chamfer through the corners of the bag, preferably by sealing thermal. 217 chamfer seals can create corners softer on the bag is full of product, which is preferred  for palletizing the bags. The corners of the bag more beyond the seals 217 in chamfer can be removed if want.

Indicated in figures 5 and 6 by the lines dotted 216A, 216B, the weakened lines extend from the edge 213 of the end of the closing flap across the region adhesive 215. Preferably, weakened lines 216A, 216B do not extend beyond detachable region 215 towards the mouth and fold 207 to preserve the integrity of the closure and to prevent product leakage.

When you want to empty the contents of the bag, the bag is opened by grasping the closure flap 205 in place suitable and taking off the flap 205 of closure or its part 219. Specifically, in Figures 5 and 6, when the edge 213 of the end of the closure flap 205 is seized on part 219 and is strip, the closing flap 205 is torn along the lines weakened 216A, 216B and part 219 detaches from the parts remaining 220 of the closure flap 205. Especially, as is see in figure 6, where the end edge 213 of the flap 205 closure is sealed with the first side wall 201 by means of Seals 212A and 212B, the unsealed part 214 acts as grip tab by means of which the flap can be grasped 205 closing. The part 219 that can then be detached by tear along the weakened lines 216A, 216B along of the detachable region, so that the bag reaches its open configuration as shown in figures 9 and 10 in the which mouth 221 is visible.

As in the previous embodiments, the detachable adhesive is selected so that its cohesive strength is less than its adhesive strength, so that (with reference to the embodiment of figures 3 to 12) as you continue pulling of part 219, part 219 is separated from the first side wall 201 in the detachable region 215 without damage substantial in part 219 or in the first side wall 201. That is, the first side wall 201 and part 219 are not torn (except along the weakened lines 216A, 216B) or not twist significantly and the first side wall 201 It remains functionally intact. When the weakened lines have been torn along its full length, part 219 can be opened (for example in fold 207) so that it can act as a dispensing nozzle for the contents of the bag dispensing through the mouth 221 formed between the first side wall 201 and the second side wall 202, as best seen in figures 9 and 10. in figures 9 and 10, different features such as the seals 217 in chamfer and adhesive regions 215 for Greater clarity

As can be seen specifically in the Figures 9 and 10, the mouth 221 through which it can be dispensed the product from bag 200 after opening flap 205 of closure is defined by the edge of the end or part of the edge 209 of the end of the first side wall 201, in combination with the inner face of the second side wall 202.

Other constructions for the mouth are possible 221. Thus, the mouth 221 can be formed as a groove in the first side wall 201, said groove is preferably (but not necessarily) attached to edge 209 of the end. The flap 205 of closure will then overlap the groove and will be peeled through of a detachable region to expose the groove. In this construction, the closure flap 205 does not necessarily have to hang on the second side wall 202 but may, for example, include a part beyond the groove (in the direction of tearing of the closing flap) that is permanently attached to the First side wall In this last construction, they are required alternative means to close the end of the bag beyond slot. Such means may include the region that can be closed. described with respect to subsequent embodiments of the invention.

In Figures 3 to 10, the flap part 205 of closure outside the detachable part 219, may be attached to the first side wall 201 by non-detachable means such as, for example, a non-detachable thermal seal or a non-adhesive detachable

The second flap 208 can also be used to provide means to re-close the bag after its opening. In particular, the second closing flap 208 may be provided with a layer of adhesive (not illustrated) that can be used to adhere the second flap 208 with the inner face of the first side wall 202. Depending on the use for which the bag, the adhesive applied to the second flap 208 can be detachable or permanent (not detachable). An adhesive can be used detachable to provide an even safer closure for the bag, after opening. More preferably the adhesive (detachable or non-detachable) applied to the second flap 208 can be initially covered by a protective tape such as a plastic material or coated paper. The protective tape prevents that the adhesive adheres the second flap 208 to the second wall side 202. When you want to close the bag again, simply the protective tape is peeled off to expose the adhesive, which can then stick on the second side wall 202. The latter construction is particularly advantageous when the bags of the invention are used to contain articles of mail order sales, as will be described later complete.

Now with reference to figures 11 and 12, it illustrates a further variant of the invention in which the bag 200 is provided with a third flap 280 at one end of the bag detached from the first fold 207. The third flap can hang on the first or second side wall 201, 202 and is attached to the respective second or first side wall 202, 201, by means of an adhesive region 300. The adhesive is preferably  detachable adhesive. The third flap 280 includes a fold 290.

During the use of this flap, the items they can be inserted first into the bag through the end 218 initially open, said end 218 is then closed by middle of the third flap 280. Then the items are transported and stored as required in the bag and, when if needed they are accessible by peeling off the closure flap 205 or the detachable part 219, as previously described, to leave exposed the mouth 221. If you need to repackage the items in the bag, such as unwanted items which have to be returned to the mail vendor, can be placed in the bag again through mouth 221. The mouth 221 is then resealed by means of the adhesive arranged on second flap 208. Additionally or alternatively, the adhesive on the detachable part 219 can be used to reseal the bag. In this case, the detachable adhesive can be resealable and / or an additional area of adhesive may be provided in part 210 or on the first side wall 201, which is protected by means of said protective tape, said tape is detached before of sealing again. When the access to items, such as for items returned to the mail order company, the bag can be opened by taking off or tearing the third flap 280.

Now particular reference will be made to the Figures 13 and 14 showing the base part of a bag of according to an embodiment of the invention. The bag, the flap of closure and associated construction details are omitted from these figures for reasons of clarity. In these figures, the bag 901 is shown in a flat condition before filling. The bag 901 comprises an end 902 of closure (which in the bag of the invention will incorporate the easy opening closure), a panel 903 of base, first and second side walls 904a, 904b and edges lateral 905a, 905b. The side walls 904a, 904b are joined in the marginal edges 905a, 905b along its full length by suitable means such as thermal and / or adhesive welding and preferably by thermal welding. However, in alternative constructions, the unions can be placed in a different place to the side edges or, when the body of the Bags are manufactured in tube form, they may be absent.

The base panel 903 comprises a fold defined by the first folds 909 'and 909' 'and a second fold  990. The fold has panel sheets or 906a and 906b fold sheets each of which has two edges 907 in chamfer. The edges Chamfer 907 are chamfer joints that comprise a line of sealed extending from each end of the second fold 990 (that is, at point X) until the first folds 909 ', 909' 'in the points Y. The edges 907 in chamfer thus form the edges of the boundary of the internal corners of the bag. Side walls 904a, 904b are attached to the base panel 9033 along these sealing lines that preferably comprise welds thermal. As best seen in Figure 14, the second fold 990 and sheets 906a, 906b of the panel rest between the side walls 904a, 904b with the outer faces of the sheets 9806a, 906b one in the direction of the other.

In the illustrated embodiments the first and second side walls 904a, 904b and base panel 903 are unitarians in that no union intervenes in a path that passes from the illustrated wall boundary side 904a at the closing end to the fold 909 ', the fold 990 and fold 909 '' and then to the limit illustrated of the side wall 904b at the closing end of the bag.

In less preferred constructions, the walls laterals 904a, 904b, for example, may not be unitary at which refers to the previously defined trajectories may be interrupted by a union formed, for example, along the fold line 990 or along or near the folds 909 ', 909``.

When the bag is in its flat condition illustrated in figures 13 and 14, edge 907 in chamfer forms preferably an angle between 30 ° and 60 °, more preferably 45º, with respect to the second fold 990.

Figure 15 illustrates a part of the bag similar to that of figures 1 and 2, but in a condition substantially open completely containing, or ready To receive a product. The side walls 904a, 904b no longer they rest substantially flat against each other as in the Figures 13 and 14, but are separated from each other. In the illustrated embodiment the side edges 905a 905b are joined each other along the side edges 905a, 905b. The unions preferably comprise thermal welds along the full length of side edges 905a, 905b though alternatively or additionally other joining means can be used such as the adhesive.

The upper edges of the side walls 904a, 904b will form the closing end of the bag and will not show additional details of the construction in this figure to more clarity A substantially rectangular base part 908 (which is part of the base panel 903) on which you can rest the bag in vertical position is defined by lines 909 ', 909 '' and 910 ', 910' 'fold and is formed by opening the sheets 906a, 906b of the panel of Figures 13 and 14. The chamfered edges 907 now rest above a horizontal plane, preferably tending towards a vertical plane, although filling the bag can cause chamfered edges 907 to move up to the vertical Chamfered edges 907 and lines 910 ', 910' ' fold define vertical parts 911a, 911b of the wall of the end that are generally triangular. The lines 910 ', 910' ' folding form the base side of parts 911a, 911b and the chamfered edges 907 form the remaining sides with the vertex of the triangles at points X. Thus, in the illustrated embodiment the vertex of the triangular parts 911a, 911b of the walls of the ends rest above the base part 908 during its use. The parts 911a, 911b are formed by an opening outside of sheets 906a, 906b of the panel and comprise end regions of panel 903 of the base. Preferably, chamfered edges 907 form an angle between 30º and 60º with respect to the lines 910 ', 910' 'fold. Additional reinforcements can be supplied (such as reinforcement welds or bonded reinforcement patches) where desired, such as at the X points where the welds of chamfered edges 907 meet the welds of the marginal edges 905a, 905b.

The chamfered parts 912 of the corners formed by chamfered edges 907 and illustrated with lines dotted in figure 13 can be removed if desired to improve palletizing, but this is not essential. If they are not removed, in the bag of figure 15 parts 912 simply form a layer Extra triangular (not illustrated) that overlaps the points Y-X-Y.

Thus, through this realization of the invention it is possible to supply a bag that can be held in stably standing in an upright position, which is suitable for transport heavy and bulky materials, which is simple and whose manufacturing presents a good cost ratio in a process automatic and that provides excellent properties of palletizing

This variant of the invention provides a bag that has an easy opening closure part and a part flat and stable base. This type of bag is particularly suitable for transporting food products partially prepared within a factory and food products prepared between the factory and the retail outlet. A example of said bag when complete is illustrated in the Figures 16, 17 and 18. Other suitable uses will be easily evident to those skilled in the art. The characteristics which are identical to those similar to figures 13, 14 and 15 not have been specifically identified and will not describe again with detail.

Essentially, the bags of this embodiment of the invention combine the flat and stable base with a closure of easy opening that is the same, or similar, as described previously and which also provides an area by means of which the bag can be sealed after being filled without disturbing the easy opening closure.

Now with reference to figures 16 and 17a, the 500 bag incorporates a flat and stable 508 base, whose construction it is preferably described with reference to figures 13, 14 and 15. The bag has part of bag 500A comprising the first side wall 501 and the second side wall 502. A flap of closure is fastened to the first side wall 501 to form the closure over mouth 521. The second side wall 502 includes a extension 553 beyond part 500A of bag and so the mouth is defined by the edge 509 of the end of the first side wall 501, in combination with the inner face 502A of the second wall side 502. The closing flap 505 joins the first wall side 501 in any of the ways described above that they allow it, or a part of it, to take off to leave the discovered the mouth 521 while allowing the first wall side 501 remain functionally intact. Thus, the 505 flap of closure can be fastened on the first side wall 501 by means of a detachable adhesive, as in the first aspect of the invention, or the detachable adhesive may be absent, as in the second aspect of the invention. More preferably, the flap 505 of closure is secured by means of detachable adhesive 515. Flap 505 closure can preferably be torn along lines weakened 516, said lines 516 preferably have the form of perforations. The bags of this embodiment may include a flap 528 at the boundary of the mouth 521, said flap 528 is functionally equivalent to flap 208 of embodiments previously described.

In the embodiment illustrated in the figures 17a-c, the bag is closed by means of a region 550 that can be closed. The true closure can be made by any suitable means 551, such as an adhesive or a heat seal In the embodiment of Figure 17a, the region that it can be closed formed from a part 552 of the end of the closing flap 505 and the extension 553 of the second wall side 502. Extension 553 extends beyond part 500a of the bag and is preferably formed integrally with the second side wall 502.

During the use of the bag, region 550 that can close opens initially to allow filling of the bag. When the desired contents have been placed in the bag, the 550 region that can be closed is closed by the measured appropriate 551. When you need to access the contents of the bag, the closing flap 505, or its part 519 (in the embodiment illustrated) takes off to expose the mouth, so that the contents can be dispensed.

Other constructions of the region are possible That can be closed. For example, the first and second wall lateral 501, 502 may have the same length so that no there is extension 553. In this case, mouth 521 is formed as a groove or a cut in the first side wall 501 and the flap 505 of closure overlaps the groove or cut. So, region 505 that can be closed can be formed by parts of the end of the first side wall 501, the second side wall 502 and the flap 505 closing. This construction is illustrated in Figure 17b. In another variant illustrated in figure 17c, the groove or cut that mouth shape 521 may be further separated from the ends of the side walls 501, 502 (that is, closer to the part 508). In this case the closing flap 505 can also be separated further from the aforementioned ends 509, 510 from the side walls 501, 502 and need not overlap mentioned ends. The 550 region that can be closed can understand then only the regions of the ends of the walls  lateral 501, 502, in this variant, the closing flap 505 must be attached to the first side wall 501 on both sides of the slot, with a part on at least one detachable side to leave the discovered the groove, while leaving the first side wall 501 functionally intact. In this variant, as illustrated in figure 17c, the closing flap 505 is joined in a way detachable by means of detachable adhesive 505 and joined together permanent by appropriate means in 554.

An additional variant of this bag embodiment is illustrated in figure 18. This bag differs from that of Figure 17 only by the arrangement of handles 560. These handles can be pierced, cut or formed from any other way to the top of the bag, preferably just above region 550 that can be closed. As an alternative, separate handles can be attached to the bag in or near the region that Can be closed.

Production procedures will now be outlined of the bags according to the invention, although it should be observed that the bags of the invention are not limited to these procedures

Initially, a procedure of production of the bags of figures 1 to 12, with reference particular to figure 19. A band 600 of plastic film is extrudes and folds in 601 to the configuration shown in the figure 19a. Then an optional second fold 602 is made which will finally supply the second optional flap 508 (figures 2, 7, 8) (Figure 19B). Then, one or more areas of adhesive are applied detachable 693 (such as a hot melt adhesive) to the surface of the bag (figure 19C) and perforations are formed 604 (figure 19D) that supply the weakened lines 216 (figures 3, 4, 5, 6). Then part 605 of the band 600 is folded and glue using the detachable adhesive 603 (figure 19E). 600 band it is cut near the first fold 601 to supply the end open 606 of the bag, by means of which the bag can finally fill up (figure 19F). To finish the band is sectioned in bags of the appropriate width and tight seals are formed heat sealable (or other joints) on the sides to result in The final bag.

Now two procedures of production of the bags according to figures 16, 17 and 18. In The first procedure, illustrated in Figure 20, is first fold a band 700 into the fold 701 (Figure 20A). Then forms a fold 702 from the fold 701 (Figure 20B) and is they form the seals 703 in chamfer in the corners of the folded parts (figure 20C). Then a part 704 of the band 700  (indicated by the dotted line) is removed (figure 20D) and apply a detachable 705 adhesive to the surface of the 700 band (figure 20E). Then a strip is applied to the detachable adhesive additional 706 which incorporates the weakened lines (716) and it It covers the area 707 of the band (Figure 20F). Finally sectioned the band and the resulting side edges are closed (by example, by thermal sealing) to form the final bags. Parts 706 and 707 supply the region that can be closed 708 (figure 20G).

In an alternative procedure, less preferred, illustrated in Figure 21, the steps illustrated in the Figures 21A to 21E are the same or similar to those in Figures 20A at 20E. In the step illustrated in Figure 21F, they are made perforations 709 (which form the weakened lines 216) in the part 707, said part 707 is then folded over a fold 710 (Figure 21G) and adheres to detachable adhesive 705. Then it cut the band 700 in the region of the fold 710 to supply the opening of the bag (figure 21H). The fold 710 is so separated of the end of the band 700 in 711 that allows the cutting of a region 712 that can be closed after crease 710. Then it section the band and seal the side edges as described previously in relation to figure 20G.

A procedure of manufacture of a bag similar to the bag of figures 1 to 12. For this bag, the mouth is separated from the ends of the bag, although the procedure can be adapted to place the mouth more near the ends of the bag.

Now with reference to figure 22, it is extruded a 750 band of plastic film and folds in the folds 751 and 752 to the configuration shown in Figure 22A. In the Figure 22A, the separation of the edges 753, 754 from the ends of The 750 band is exaggerated for clarity. also can include an optional third fold forming a second flap optional hanging from edge 753 or 754. This second flap is similar in its construction and operation to the second flap that hangs from the fold 602 of figure 19.

Then, one or more areas of adhesive are applied detachable 755 (such as a hot melt adhesive) to the surface of the bag. Adhesive 756 is also applied on the side opposite of the recess 757, said adhesive 757 can be detachable or permanent (figure 22B). Then an additional band 758 is applied to regions 755, 756 of adhesive to cover (and close) the gap 757. The additional band includes weakened lines 759 (figure 22C). Finally, band 750 is sectioned to form bags individual and one side 760 is sealed, for example, by sealing thermal or by adhesive (figure 22D). The other end 761 is open to fill the bag and can be closed in region 762 after filling the bag (figure 22E). In a variant alternative, after the step illustrated in Figure 22C, the band 750 can be sectioned, as in Figure 22D, to form individual bags, and thus both side edges can be sealed 761 and 763, for example, by adhesive or thermal sealing. In this variant, to provide an access to fill bag, the 752 fold can be cut (both before and after it section band 750). This part of the end can be closed then after filling the bag, such as by sealing thermal or adhesive.

Figure 23 illustrates another variant of the bags of the invention in which the mouth is separated from the ends of the bag. With reference to Figure 23, bag 560 includes a part 508 flat and stable base, whose construction is preferably as described with reference to figures 13 a 15 and with reference to figures 16 and 17. Bag 560 includes also a region 550 that can be closed from any of the previously described forms, after filling the bag. Mouth 521 of the bag 560 is in the form of a groove or a recess 562. The mouth 521 is closed by means of a closing flap 565 that covers the gap 562. The closing flap is attached to the front face 561 of the bag by means of a region of detachable adhesive 563 and, on the other side of the gap 562, by means of a region of 564 adhesive detachable or permanent. The closing flap includes weakened lines 566 along which the flap 565 closure so that a part 569 can be peeled off through the region of detachable adhesive 563 to leave the discovered mouth 521.

Figure 24 illustrates a procedure for doing the bag of figure 23. In this procedure, a band 770 of plastic film and folds over a fold 771 and 772 to the configuration shown in Figure 24A. In the figure 24A the separation of the edges 773, 774 from the ends of the band 770 is exaggerated for clarity. You can also include a optional third fold forming an optional second flap that hangs from the edge 753 or 754. This second flap is similar in its construction and operation to the second flap that hangs from the fold 602 in figure 19.

Then a 775 fold is formed from the fold 771 (figure 24B) and chamfered seals are formed 776 in the corresponding corners of the fold part (figure 24C). Subsequently, fold 772 is cut to provide a end 776 of the resulting bag opened for filling (figure 24D). One or a few regions of detachable adhesive 777 is applied in the bag next to the hole 778 and also one or some regions of detachable adhesive 777 in the bag next to the hole 778 and regions 779 of adhesive are also applied on the side opposite of gap 778. Adhesive regions 779 may be detachable or non-detachable. The positions of regions 777 and 779 of adhesive can be inverted if desired (Figure 24E). Then an additional 780 band is applied, which includes lines weakened 781, to regions 777, 779 of adhesive to cover and close hole 778 (figure 24F). Finally, the band 770 is section to form individual bags and the side edges are seal, such as by thermal or adhesive sealing. After the filling the bag, the open end 776 can be closed by suitable means in region 782 that can be closed.

Claims (19)

1. A plastic bag (500) to transport and store powder or granular material in bulk or ingredients bulk food, the bag (500) has an open end and a closed end (508) and comprises:

a first and a second side wall (501, 502) that together form a part (500A) bag that has front and back faces;

One mouth (521) to access the inside of the bag (500) during use;

a flap of closure (505) that covers and closes the mouth and that includes a region (515) that is detachably attached to the front face so that at least part of the closing flap (505) can be detached from the front face through the region (515) detachably attached to expose the mouth (521), the front face remaining functionally intact;

which is characterized because:

the flap (505) closure is formed separately from the first and the second wall lateral (501, 502) and the mouth (521) is different from the extreme open;

the region detachably bonded comprises at least one area of adhesive that is extends from one side edge of the closing flap to the other without interruption whereby it seals the mouth not allowing the output of the contents of the bag;

and because the bag (500) also includes:

A region (550) that can be closed arranged adjacent to the open end of the bag and other than the mouth (521) and the flap part of closure that can be detached in said region (550) that can be Close the open end of the bag can be closed by the user by thermal sealing, after they have been inserted the contents inside the bag through the open end, the thermally sealable faces are exempt from any adhesive.

2. A plastic bag (500) to transport and store powder or granular material in bulk or ingredients bulk food, the bag (500) has an open end and a closed end and comprises:

a first and a second side wall (501, 502) that together form a part (500A) bag that has front and back faces;

One mouth (521) to access the inside of the bag (500) during use;

a flap of closure (505) that covers and closes the mouth;

which is characterized because:

the mouth (521) is other than the open end;

the flap (505) closure is formed separately from the first and the second wall lateral (501, 502) and includes a region comprising at least one adhesive area, by means of which the closing flap is attached to the front face and extending from a side edge of the closing flap to the other without interruption, whereby seals the mouth not allowing the contents of the bag, the closure flap includes at least one weakened line that defines a part of it alone that does not include any part of the region that is attached to the front face and said part can be opened ripping along the weakened line to expose the mouth (521) of the bag;

and because the bag (500) also includes:

A region (550) that can be closed arranged adjacent to the open end of the bag (500) and other than the mouth (521) and the flap part which can be opened by tearing, by means of said region (550) that the bag can be closed (500) can be closed by the user by heat sealing, after the contained inside the bag through the open end, the thermally sealable faces are exempt from any adhesive.

3. A plastic bag (500) like the claimed in claim 1 or 2, wherein the first wall side (501) forms the front of the bag (500), the second wall side (502) forms the back of the bag (500), the walls laterals (501, 502) have substantially the same length, the mouth (521) comprises a groove formed in the front face (501) and the region (550) that can be closed includes parts of the ends of the first and second side walls (501, 502). 4. A plastic bag (500) like the claimed in any preceding claim, wherein the front face includes a weakened line that can break to form the mouth (521). 5. A plastic bag (500) such as claimed in claim 3 or 4, wherein the region (550) that can be closed also includes a part of the end of the flap (505) closure. 6. A plastic bag (500) like the claimed in claim 1 or 2, wherein the first wall side (501) forms the front of the bag (500), the second wall side (502) forms the back of the bag (500), the second side wall (502) has an extension (553) beyond the part (500A) of the bag, the closing flap (505) covers a part of the first side wall (501) and extension (553) of the second wall side (502), and the region that can be closed includes the extension (553) of the second side wall (502) and a part of the end of the flap (505) closure. 7. A plastic bag (500) like the claimed in claim 6, wherein the mouth (521) is defined by the edge of the end of the first side wall (501). 8. A plastic bag (500) like the claimed in any preceding claim, comprising also a second flap (528) that hangs by means of a fold of an edge of the mouth (521) and extending into the interior of the bag. 9. A plastic bag (500) according to the claim 8, wherein the second flap (528) can be joined by adhesive means to the inner face of the second side wall (502). 10. A plastic bag (500) like the claimed in any preceding claim, comprising also a base part (508) on which the bag (500) can stand stably when it contains a product. 11. A plastic bag (500) such as claimed in claim 10, wherein the part (508) of base comprises:

One panel (903) base connected along its opposite sides to the respective first and second side wall (904a, b) by means of first folds (909 '909' '), said panel (903) also has a second fold (990), coextensive with the width of said walls lateral (904a, b) and substantially parallel with said first folds (909 ', 909' '), said second fold (990) divides the panel (903) of base one a first and a second sheet (906a, b) of panel, so that the second fold (990) and the sheets (906a, b) of panel rest between said side walls (904a, b) with the external faces of the panel sheets (906a, b) looking at each other; Y

the boards chamfered (907) comprise a sealing line that extends from each end of said second fold (990) to each first fold (909 ', 909' '), along said sealing lines (907) the first and second side walls (904a, b) are joined respectively with the base panel (903).

12. A plastic bag (500) such as claimed in claim 10, wherein the part (508) of base comprises a generally rectangular base panel (908) that it has opposite side edges and opposite end edges and parts (911a. B) of generally triangular end wall each of which hangs along one of its sides (910 ', 910' ') of the base of a respective edge of the end of the base panel (908), said base panel (908) is connected to the respective first and second side wall by means of first folds (909 ', 909' ') coinciding with said respective lateral edges, said parts (911a, b) triangular end wall have a vertex (X) located during use above said base panel (908), and they have side edges comprising sealing lines (907) that they extend between said vertex (X) and the respective corners of said base part (908) along which the first and second side wall join the mentioned ones respectively parts of the end wall. 13. A plastic bag (500) such as claimed in any one of claims 1 to 9, wherein The closed end of the bag is supplied by a third flap that covers and is detachably attached to the first or to the second side wall (501, 502), said third flap hangs on the second or the first side wall (502, 501) at the end of the bag (500) away from the open end. 14. A plastic bag (500) such as claimed in claim 2 or in any claim precedent when it depends on it, which includes at least two lines weakened (516) along which said part can be opened by tearing. 15. A plastic bag (500) such as claimed in claim 1 or in any claim precedent when it depends on it, in which the flap part (505) that can be detached is defined by at least one weakened line (516) along which the flap is torn (550) closure to expose the mouth (521) of the bag.

         \ newpage
      

16. A plastic bag (500) such as claimed in claim 15, wherein the part (519) of the flap (505) that can be detached is always defined by two weakened lines (516). 17. A plastic bag (500) such as claimed in claim 16, wherein the lines weakened (516) extend from an edge of the end of the closing flap (505) far from the region (550) that can be close to points near the mouth (521). 18. A plastic bag (500) such as claimed in claim 1 or in any claim precedent when it depends on it, in which the part (519) of the Closing flap that can be detached is attached to the front face by means of a detachable adhesive. 19. A plastic bag (500) according to any one of claims 14 to 18 wherein the line or weakened lines (516) are perforations formed in the flap of closing.