CN1316964A - Bags with an easy-open structure - Google Patents

Abstract

A plastic bag has a mouth portion covered by a closure flap. To open the bag, the closure flap can be peeled open without damaging the walls of the bag in which the mouth is formed. The closure panel is preferably attached to the bag by a peelable adhesive and preferably has a line of weakness along which the closure panel can be torn. The bag variant has a base with a flat area that allows the bag to stand stably.

Description

Bags with an easy-open structure

The present invention relates to bags or paper bags, and more particularly to plastic or paper bags having an improved easy-open construction. The invention also relates to bags or paper bags which can stand stably without support.

The bags of the present invention can be of any suitable size from relatively small (e.g. 1 liter capacity or less) to larger bags and are well suited for industrial processing within or between factories, or between factories and retail outlets. It is used for transporting food and is most suitable for the food processing industry. The bags of the present invention can also be used as outer packaging for certain solid or liquid consumer products such as cleaning agents. The bag can also be used in home delivery services, especially where products need to be returned to the supplier by post.

Many different types of plastic bags are known, but a particular problem is how to provide a bag which incorporates an easy-open closure, which can be manufactured easily and cheaply, is convenient and reliable to use, and is suitable for certain uses. , suitable for loading heavy objects. The present invention seeks to provide a bag with a closure that meets these requirements. The present invention further seeks to provide a bag capable of standing upright on a surface in a stable manner, especially for special applications, containing relatively heavy products.

The bags of the invention are particularly suitable for containing loose products in powder, granular or liquid form. Such as loose chemicals and loose ingredients for human and animal food and household products such as washing powders and detergents; food products such as finished or semi-finished products; household products; and garden products such as peat or compost. In the food industry, plastic and paper bags are used in particular to transport food, ingredients or semi-finished products within production sites or between plants. In this context, bulk products may include retail consumer products such as liquid and solid detergents, dry foods, food ingredients and finished foods for which the bag of the present invention may form an outer packaging. The amount of loose product suitable for bagging will vary depending on the specific application, for example, for finished food products, the amount may not be large.

The invention also relates to bags or paper bags, in particular plastic or paper bags capable of standing stably on a surface when containing solid or liquid products, especially relatively heavy products.

Therefore, the present invention provides a kind of plastic bag in the first aspect, it comprises:

first and second side walls that together form a bag portion having front and rear surfaces;

a mouth formed on the front surface of the bag for accessing the interior of the bag; and

A closure flap covering and closing the mouth, the closure flap having a region releasably attached to the front surface:

At least a portion of the closure flap is peelable from the front surface across the peelable attachment region to expose the mouth, while the front surface remains functionally intact.

In a variation of this aspect of the invention, the portion of the closure flap that is peelable from the front surface is bounded by at least one line of weakness extending through the region of the peelable connection along which the closure flap can be torn to reveal mouth of the bag.

In addition, the present invention provides a kind of plastic bag in the second aspect, it comprises:

first and second side walls that together form a bag portion having front and rear surfaces;

a mouth formed on the front surface of the bag for accessing the interior of the bag;

and a closure flap covering and closing the mouth, the closure flap having a region attached to the front surface;

wherein the closure flap has at least one line of weakness delimiting a portion thereof that does not include any portion of the region connected to the front surface that can be opened to reveal the mouth of the bag by tearing along the line of weakness .

In one embodiment of these aspects of the invention, the closure flap has an arcuate line of weakness extending from points on the closure flap adjacent the mouth to an end edge of the closure flap.

To facilitate opening the bag, the bag preferably has at least one finger hole formed in the closure flap above the line of weakness through which the closure flap can be gripped for tearing.

In another embodiment of these aspects of the portion of the invention (i.e. the peelable portion of the first aspect or the portion bounded by the at least one line of weakness of the second aspect) at least two lines of weakness in the enclosed sheet As defined, the closure panel can be torn along the line of weakness to expose the mouth of the bag.

Preferably in this embodiment the line of weakness terminates in one or more finger holes formed in the closure flap through which the closure flap can be gripped for tearing. This structure facilitates opening the bag.

In the above embodiments, in another preferred structure according to the first aspect of the present invention, the line of weakness extends from the end edge of the closure flap to points adjacent to the mouth.

Other possible configurations for frangible lines and closures include the following:

The line of weakness is substantially straight and approximately parallel to the edge of the bag; or

the ends of the line of weakness at the end edge of the closure flap are farther apart than the ends of the line of weakness adjacent the mouth; or

the ends of the line of weakness at the end edges of the closure flap are spaced apart to define a finger by which the closure flap can be gripped for tearing; and/or

The closure flap is sealed to the front surface along its end edge portions extending from the respective lines of weakness to the sides of the bag.

In a particularly preferred construction, the line of weakness enables the portion of the closure flap bounded by the line of weakness to assume the shape of the dispensing opening when torn along the line of weakness.

In a particularly preferred embodiment of the first aspect of the invention, the portion of the peelable closure flap is attached to the front surface by a peelable adhesive. Hot melt adhesives are especially preferred. Alternatively, the portion of the peelable closure flap may be joined to the front surface by a peelable heat weld or a peelable heat-sealed region.

In a particularly preferred embodiment of the invention, the line of weakness is a perforation formed in the closure flap. Alternatively, the lines of weakness may include lines where the closure flap is made thinner, or score lines in the material of the closure flap.

In a particularly useful embodiment of the invention, the plastic bag further includes a closable region formed at the front end of the bag for closing the bag after filling. This structure allows the bag to be filled from the same end as the easy open portion, which end can be sealed after filling. Also, other advantageous structures can be formed at the other end of the bag, in particular structures that do not allow filling of the bag from the other end. The closable area may be closed by any suitable means. Examples of suitable means to close the closable area include heat sealing, adhesives (such as an adhesive layer initially covered by a removable protective tape), and snap fastening devices, such as extending along the width of the closable area And those devices that include a convex portion on one side and a concave portion on the other side that snap together to form the seal.

In another preferred embodiment of the invention, the first side wall forms the front of the bag and the second side wall forms the rear of the bag, said side walls having substantially the same length.

In preferred constructions according to this embodiment, the mouth comprises a slit formed in the front surface.

Additionally, the bag includes another line of weakness formed in the front surface that can be broken to form the mouth.

The closable region may include ends of the first and second side walls. These ends, for example, may be heat sealed after filling to close the bag. In some constructions, the sealable region also includes an end of the closure flap which may also form part of the heat seal (or other means of closure).

In further preferred embodiments, the first side wall forms the front of the bag, the second side wall forms the rear of the bag, and the second side wall has an extension beyond the bag portion. The extension cooperates with the closure flap and the first side wall to define a mouth and form an easy-open closure. Therefore, preferably, the closure flap covers a part of the first side wall and an extension of said second side wall.

In this way, the mouth is delimited by the end edge of the first side wall, said end edge being revealed when the closure flap is lifted, thereby allowing access to the interior of the bag.

In this preferred construction, the closable region also includes the extension of the second side wall and the end of the closure flap.

A handle for carrying the bag is formed in or adjacent to (e.g., just above) the closable region, such as by cutting, perforating, or otherwise extending the first and second side walls, the second side wall, or the closure flap Appropriate holes are formed in the part (as appropriate for a particular configuration). Alternatively, a separate handle may be attached to or near the closable region.

In one or more particularly preferred embodiments of the above aspects of the invention, the bag further comprises a second panel overhanging the edge of the mouth by means of the border fold and extending into the interior of the bag.

Most preferably, the second panel is passed over the inner surface of the adhesively affixed second side wall. Peelable adhesives are desirable.

In another preferred embodiment of the first aspect of the present invention, on the portion of the peelable closure sheet, the portion extending from the border of the portion closest to the mouth to the border of the portion farther from the mouth Any paths must pass through the strippable connection area.

Moreover, in another preferred embodiment of the first aspect of the present invention, a path along the first side wall parallel to the mouth is entirely within the peelable attachment region, at least in the peelable portion of the closure flap. within. These embodiments ensure that there is an uninterrupted seal (by means of the peelable adhesive) across the entire width of the peelable area, so there is no path for powder or liquid product to leak through the easy open seal.

In using the bag of the present invention, it is convenient that the bag can stand stably without a support, both during filling and after filling. Accordingly, in a preferred embodiment of the invention, the bag further comprises a base formed at the end of the bag remote from the closable region to provide a generally flat region enabling the bag to stand stably.

In a preferred structure according to this embodiment, the base includes:

a base plate connected along opposite sides thereof to the first and second side walls respectively by first folds, said base plate also having a second fold extending generally parallel to the width of said side walls at said first crease, said second crease divides the base plate into first and second leaves, the second fold and the leaf being between said side walls, the outer surfaces of the leaves facing each other; and

A miter seal including a seal line extending from each end of the second crease to each first crease along which the first and second sidewalls respectively abut the substrate.

The miter seal forms mitered corners which can be removed if desired to improve bag handling, but are not critical. That is, the bag of the present invention needs to be suitable for transport on a plywood, on which multiple bags including a plywood load are often shrink-wrapped (or otherwise packaged) in order to hold the bag on the plywood. In prior art bags (without a stable flat base), in the absence of a mitered seal, the product contained in the bag is able to fill into the corners of the bag. This causes the corners to be hard and sharp so the corners will tend to cut or tear the shrink wrap and/or adjacent bags. Therefore some prior art bags (without the flat base structure of the present invention) have mitered seals at the corners to prevent product from getting into the corners. In this way, the corners, while still sharp, are softer and less prone to damage. In the present invention, the miter seal is formed in one piece on a flat stable base, but can also serve to add flexibility to improve shipping. Shipping can be further improved by removing the mitered corners, but this is not critical. Similarly, where the bags of the present invention form the outer packaging for consumer goods, the mitered corners are removed to avoid sharp corners that would be inconvenient to consumers and allow the bags to be more easily stacked on store and supermarket shelves.

In the case of a bag with a flat, stable base, the preferred configuration according to the invention also delimits the bag in the filled expanded state. Thus, in this construction, the base comprises a generally rectangular base plate having opposed side edges and opposed end edges, and triangular shaped end wall portions each depending along its base side from the On each end edge of the base plate, the base plate is respectively connected to the first and second side walls by a first fold coincident with the respective side edges, and the triangular end wall portion has a shape which is positioned above the base plate in use. and having a side edge comprising a seal line extending between the tip and each corner of the base, the first and second side walls being respectively connected to the end wall portion along the seal line .

In both the former and the latter structures, the substrate is preferably but not critically integrated with the first side wall.

In the former and latter constructions according to this embodiment, the sealing line (of the mitered seal) preferably comprises heat welding.

The seal line of the miter seal (as defined in the preceding structure) desirably forms an angle between 30° and 60° relative to the second crease, more specifically, the miter seal forms an angle of 45° relative to the second crease. angle.

In embodiments of the invention where there is no closable region and the first and second side walls have substantially the same length, the mouth may preferably be delimited by an end edge of the first side wall. This is preferably achieved by having the closure flap overhanging the second side wall. Most preferably, the closure flap is integral with the second side wall and depends from the second side wall along a crease. The crease is therefore preferably parallel to and adjacent to the end edge of the first side wall delimiting the mouth.

In constructions where the bag does not require a stable base, the bag can be constructed so that the end of the bag that is separate from the easy-open closure is also openable. In this construction, the bag is also provided with a third panel covering and releasably connected to the first or second side wall, the third panel depending from the second or first side wall at the end of the bag remote from the closure panel superior.

In other definitions of certain bags of the first aspect of the present invention, the plastic bag includes first and second opposing side walls having substantially congruent end edges, and a closure covering one end edge of the first side wall. The closure panel is suspended from the end edge of the second side wall and has a first crease parallel to and adjacent to the end edge, the closure panel also has a region releasably connected to the first side wall, the first and the second side wall are connected along their side edges, wherein at least a portion of the closure panel can be peeled from the first side wall across the peelable connection area to expose the interior of the bag, while the first side wall remains functionally complete.

In other definitions of certain bags of the second aspect of the present invention, the plastic bag includes first and second facing sidewalls having substantially coincident end edges, and an end edge covering one end edge of the first sidewall. closure flap, the closure flap is suspended on the end edge of the second side wall and has a first crease parallel to and adjacent to the end edge, the closure flap also has a region connected to the first side wall, the first and second The two side walls are connected along their side edges, wherein the closure flap has at least one line of weakness delimiting a portion thereof which does not include any part of the area connected to the front surface, by A thread tear can open the section to reveal the mouth of the bag.

For a better understanding of the invention, and to show how it works, reference is made to the following drawings, by way of example only, in which:

Figure 1 is a schematic perspective view of a bag according to a variant of the present invention;

Fig. 2 is a sectional view along line A-A among Fig. 1;

Figure 3 is a schematic plan view of a bag according to another variant of the present invention, showing a line of weakness in the closure flap;

Figure 4 is a schematic plan view of a bag according to another variant of the invention, showing two lines of weakness in the closure flap;

Fig. 5 is a schematic plan view according to yet another modification of the present invention;

Figure 6 is a schematic plan view of another variant according to the present invention;

Fig. 7 is a sectional view along line D-D in Fig. 6;

Fig. 8 is a sectional view along line B-B in Fig. 6;

Fig. 9 is a plan view of the bag shown in Fig. 5 when it is in an open state;

Figure 10 is a plan view of the bag shown in Figure 6 when it is in an open state;

Figure 11 is a schematic plan view of a bag sealable at both ends according to another variant of the present invention;

Fig. 12 is a sectional view along line E-E in Fig. 11;

Figure 13 is a schematic plan view of a portion of a bag according to another embodiment of the present invention;

Fig. 14 is a sectional view along line A-A in Fig. 13;

Figure 15 is a partial view of the bag shown in Figure 13 when it is in an open state;

Figure 16 is a schematic plan view of a bag incorporating the base structure shown in Figures 13 to 15 according to the present invention;

Figure 17a is a cross-sectional view along line F-F in Figure 16;

Figures 17b and 17c show a variation of the bag shown in Figures 16 and 17a;

Figure 18 is a schematic plan view of a bag of similar construction to the bag shown in Figure 16 according to the present invention;

Figures 19 to 22 illustrate a method of manufacturing a bag according to the invention.

Figure 23 is a schematic plan view of a bag according to the present invention, wherein the mouth is not adjacent to one end of the bag; and

FIG. 24 shows a method of making the bag shown in FIG. 23 .

In this application, unless otherwise indicated, or unless the text requires otherwise, the bag of the present invention is described and defined in its flat state prior to filling. That is, the bag is described and defined in terms of a configuration in which the side walls are affixed flat together with substantially no gaps therebetween. Obviously, when the bag is filled with product, the side walls of the bag become separated, changing the shape of the bag.

Figures 1 to 12 illustrate a construction of the bag in which no base for stable standing is required. In these figures, bag 200 includes bag portion 200A and closure flap 205 . The bag portion 200A is formed by a first side wall 201 and a second side wall 202 . The side walls 201 and 202 face each other and lie flat together, and in these embodiments, the side walls 201, 202 have the same length. The walls 201 , 202 are joined together along their sides 203 , 204 by eg heat sealing (heat sealing along sides 203 and 204 is not specifically shown for clarity). In another configuration, the walls of the bag portions may be formed into tubes so that there is no significant joint or seal along their sides.

The closure flap 205 is located over one end region of the first side wall 201 and in these embodiments the closure flap 205 overhangs the second side wall 202 at an end boundary edge 206 of the second side wall 202 . The closure flap 205 may be attached to the second side wall by a connector, but in these embodiments the closure flap 205 is preferably integrally formed with the second side wall 202 and is suspended from the second side wall 202 by the fold 207 . It can be seen that the crease 207 is adjacent to and substantially parallel to the end edge 209 of the first side wall 201 (for clarity, in FIGS. and the space between the closure pieces 205 is enlarged.). End edge 209 defines the mouth of bag 200 when the bag is opened. An optional second panel 208 extending into the interior 211 of the bag 200 is attached by border crease 210 to the end border edge 209 of the first side wall (ie the border edge of the mouth). The end edge 222 of the second sheet 208 is shown in dotted lines in FIGS. 5 and 6 .

The closure flap 205 is adhered to the first side wall 201 by a peelable attachment area or areas 215 . The peelable attachment area 215 can take a variety of forms, but preferably includes a peelable adhesive and is a hot melt adhesive. A peelable adhesive may be applied to either surface of the first side wall 201 or to the surface of the closure flap 205, or both. Another example of a peelable adhesive may be a pressure sensitive adhesive comprising two non-adhesive components, a first part of which is applied to the closure flap and a second part of which is applied to the first side wall. When the two parts are brought together and pressure is applied, a tacky bond is formed. Alternatively, the peelable adhesive may be a permanent or non-permanent adhesive or a melt adhesive applied to either the surface of the first side wall 201 or the surface of the closure flap 205 or both. .

The region or regions of peelable adhesive 215 may be of any number of different suitable shapes. For example, the area 215 may occupy the entire area of the first side wall 201 below the closure flap 205, or only a part of this area. The areas of peelable adhesive may be strips or stripes extending sideways beyond the first side wall or extending to a diagonal or curved (wavy) path. The region of peelable adhesive may also be intermittent across the first sidewall.

Preferably, for the area or areas of peelable adhesive, along the surface of the first side wall 201 from its end boundary edge 209 (i.e. from the mouth) to the edge of the closure flap 213 (i.e. away from the mouth) edge) path forward is not possible without passing over the area of the peelable adhesive. Where, as further described below, only a portion of the closure sheet is peeled off, the above described approach may only be applied to that portion.

Particularly preferably, a continuous region of peelable adhesive is substantially parallel and adjacent to the end boundary region 209 of the first side wall 201 (ie adjacent to the mouth), see FIG. 5 for details. This construction helps ensure the integrity of the seal.

The area or areas 215 of peelable adhesive may also be resealable so that the bag can be reclosed after being opened by the area or areas 215 of peelable adhesive.

For example, permanent or non-permanent adhesive, hot melt or solvent-based adhesive applied to either surface of the first side wall 201 or the surface of the closure flap 205, or both, also occurs upon opening the bag. migration, thereby allowing the bag to be resealed.

Other configurations for the peelable attachment area 215 include the use of specific adhesives whose adhesive properties vary with ambient temperature, thereby allowing the bag to be used at extreme temperatures. In some cases, these adhesives are non-peelable at room temperature.

Other configurations for the peelable connection area 215 include the use of frangible adhesives.

Other configurations for the peelable connection region 215 have peelable heat welds and peelable heat seal regions. In order to provide a peelable heat weld or heat seal, the strength of the weld or seal should be weak to some extent. This is achieved by trapping some kind of impurity between the materials to be welded or sealed. The impurity can be chosen from a wide range of materials, but examples thereof include inks and varnishes or a third film layer which is more fragile welded to the material layer than the material is welded to itself.

Referring now in particular to Figures 1 and 2, the closure flap 205 is peeled via the peelable attachment region 215 to uncover the opening 221, thereby simply opening the bag as shown. In this and other embodiments of the invention, a peelable adhesive is used, the adhesive being selected to have a cohesive strength that is less than an adhesive strength. Therefore, in the embodiment shown in Figures 1 and 2, when the closure flap is gripped and pulled at its front edge 213, it separates from the first side wall 201 at the peelable region 215 without Substantial damage is done to the closure flap 205 or to the first side wall 201 . Neither the closure flap 205 nor the first side wall 201 has been torn, although they may have been somewhat deformed, but any deformation of the first side wall 201 is insignificant in terms of its function.

In this and other embodiments, the optional second panel 208 helps maintain the integrity of the closure when the bag 200 is filled with contents. The second sheet 208 can effectively prevent the contents of the bag from seeping into the area around the first fold 207 between the first side wall 201 and the closure sheet 205 in an excessive amount, which might otherwise cause the side wall 201 and/or the closure sheet to 205 so that they become separated at the peelable region 215. The closure of the bag is broken, allowing the contents to leak or flow out.

In a particularly preferred variant of the invention, the closure flap 205 is provided with one or more lines of weakness along which the closure flap 205 can be torn to open the bag and expose its interior. The lines of weakness preferably take the form of perforations in the closure flap 205 .

Referring now to Figures 3 and 4, the bag is shown with only one line of weakness. The line of weakness 216 is in the form of an arc extending through the peelable connection region 215 from a point W-W adjacent the mouth and the first fold 207 towards the edge 213 of the closure flap 205 . The line of weakness 216 defines a portion 219 of the closure flap which can be clipped and torn along the line of weakness 216 to open the bag. Preferably, the ends of the line of weakness 216 do not extend over the peelable region 215 towards the mouth to maintain an integrity of the closure and prevent product leakage.

To facilitate opening the bag, the embodiment shown in FIG. 4 includes a finger hole 250 through which the closure flap 205 can be gripped to initiate a tear along the line of weakness 216 . Alternatively, a small piece can be attached at a similar point, and the small piece can be gripped between fingers to initiate the tear. As shown in FIG. 4, a permanent adhesive line 240 is provided between the end edge 213 of the closure flap and the line of weakness 216 to help retain the closure flap 205 until the bag 200 is opened.

In other embodiments of the invention than shown in FIG. 4, it may be desirable not to use adhesive in the area of the closure flap bounded by the line of weakness 216. As shown in FIG. In this case, the closure flap 205 must be sealed to the first side wall 201 (for example by a non-peelable adhesive or heat seal) in the outer region of the portion 219 to provide the necessary seal. For example, this may be achieved by a permanent bond line 240 and sealed at the side edges 205A, 205B.

Referring now to Fig. 5 to Fig. 10, they show the various variations of bag of the present invention, and these bags have two lines of weakness 216A, 216B, and these two lines of weakness define a portion 219 of closure flap, can be along the line of weakness Tear off that part to open the bag. Additional features incorporated into other embodiments of the invention are also shown. In this regard, the closure flap 205 may be sealed to the first side wall 201 at its end edge 213 and at its side edges 205A, 205B ( FIG. 5 ) by seals 212A, 212B ( FIG. 6 ), but these Not always the key. Seals 212A and 212B are preferably heat-sealed, however, cohesive seals may also be made with practical permanent or non-permanent adhesives. Mitered seals 217 may be formed across the corners of the bag, preferably by heat sealing. The miter seal 217 creates soft corners on the bag when the bag is filled with product, which is preferred for bag loading. The corners of the bag beyond the mitered seal 217 can be removed if desired.

The line of weakness extends from the end edge 213 of the closure flap through the adhesive area 215 as indicated by the dotted lines 216A, 216B in FIGS. 5 and 6 . Preferably, the lines of weakness 216A, 216B do not extend beyond the mouth-facing peelable region 215 and crease 207 to maintain closure integrity and prevent product leakage.

When it is desired to empty the contents of the bag, the bag is opened by clamping closure flap 205 in place and peeling closure flap 205 or portion 219 thereof. Specifically, in FIGS. 5 and 6, when the end edge 213 of the closure sheet 205 is pinched and pulled at the portion 219, the closure sheet 205 is torn along the lines of weakness 216A, 216B, and the portion 219 is separated from the closure. The remainder 220 of sheet 205 is phase separated. As shown in Figure 6, especially the end edge 213 of the closure piece 205 is sealed to the first side wall 201 by seals 212A, 212B, and the unsealed portion 214 acts as a finger, by which the closure piece 205 can be clamped. . By tearing along the lines of weakness 216A, 216B in the peelable area, the portion 219 can be separated so that the bag obtains the open configuration shown in FIGS. 9 and 10 and exposes the mouth 221 .

In the embodiments described above, the peelable adhesive is chosen such that its cohesive strength is less than its cohesive strength, so (see the embodiments of FIGS. Separation from first sidewall 201 in peelable region 215 without substantial damage to portion 219 or first sidewall 201 . That is, first sidewall 201 and portion 219 are not torn (except along lines of weakness 216, 216A, 216B) or deformed significantly, and first sidewall 201 remains functionally intact. When the lines of weakness have been torn along their entire length, the portion 219 can be opened (for example at the crease 207) to become a dispensing spout for the contents of the bag through the opening formed in the first side wall 201. The mouth 221 between the second side wall 202 and the second side wall 202 is allocated, which can be seen most clearly in FIGS. 9 and 10 . In FIGS. 9 and 10 , various features such as miter seal 217 and adhesive area 215 are omitted for clarity.

In particular in FIGS. 9 and 10 it can be seen that the mouth 221 for dispensing the product in the bag 200 after opening the closure flap 205 is separated by the end edge, or part of the end edge 209 of the first side wall 201 The inner surface of the second side wall 202 is defined.

Other configurations of the mouth 221 are also possible. Accordingly, the mouth 221 may be formed as a slit in the first side wall 201 , which is preferably, but not necessarily, adjacent to the end edge 209 . The closure flap 205 will cover the slit and can be torn through a peelable area to expose the slit. In this structure, the closure flap 205 does not have to overhang the second side wall 202, but, for example, it has a portion beyond the slit (in the direction of tearing the closure flap), which is permanently adhered to the on the first side wall. In the latter construction, other methods are required to close the ends of the bag beyond the slit. Such methods include closable regions as described in later embodiments of the present invention.

In FIGS. 3-10, the portion of closure flap 205 other than peelable portion 219 is attached to first side wall 201 by non-peelable means, such as a non-peelable heat seal or a non-peelable adhesive.

The second sheet 208 may also be used to provide a means of reclosing the bag after opening. Specifically, the second sealing piece 208 may be provided with a layer of adhesive (not shown in the figure) for adhering the second piece 208 to the inner surface of the first side wall 201 . Depending on the intended use of the bag, the adhesive applied to the second sheet 208 may be peelable or permanent (non-peelable). A peelable adhesive may be used to provide a secure closure to the bag prior to opening. More preferably, the adhesive (peelable or non-peelable) applied to the second sheet 208 is initially covered with a protective tape such as a plastic material or coated paper. The protective tape prevents the adhesive from adhering the second sheet 208 to the second side wall 202 . When the bag needs to be reclosed, the protective tape can simply be peeled off to expose the adhesive, which is then adhered to the second side wall 202 . The latter construction is particularly advantageous when the bag of the present invention is used to hold mail order goods, as will be described in more detail below.

Referring now to FIGS. 11 and 12 , a further variation of the invention is shown in which the bag 200 is provided with a third panel 280 at the end of the bag remote from the first crease 207 . The third sheet overhangs the first or second side wall 201 , 202 and is attached to the second or first side wall 202 , 201 by the adhesive area 300 . The adhesive is preferably a peelable adhesive. The third piece 280 has a crease 290 .

In use of the flap, goods are first inserted into the bag through the initial open end 218 which is then closed by the third flap 280 . Then the goods are transported or stored in the bag as required, and when it needs to be opened, the closure sheet 205 or the peelable part 219 can be peeled off, exposing the mouth 221 as previously mentioned, if the goods need to be repackaged in the bag, for example, Returning unwanted items to the mail order supplier, the items can be relocated in the bag through the mouth 221, which is then resealed by the adhesive provided on the second sheet 208. In addition, the adhesive on the peelable portion 219 can be used to reseal the bag. In this case, the peelable adhesive is resealable, and/or an additional area of adhesive is provided on the portion 219 or the first side wall 201, which is protected by the protective tape, upon resealing. Remove the protective tape before. When the goods need to be removed again, such as to return the goods at a mail order company, the bag can be opened by peeling or tearing off the third panel 280 .

Referring now in particular to Figures 13 and 14, there is shown the base of a bag according to one embodiment of the present invention. Details of the mouth, closure flaps and related structures have been omitted for clarity. In these figures, the bag 901 is shown in a flat state prior to filling. The bag 901 includes a closed end 902 (the end in the bag of the present invention incorporating an easy-open closure), a base plate 903, first and second side walls 904a, 904b and side edges 905a, 905b. The side walls 904a, 904b are connected along their entire length at the edges 905a, 905b by suitable means, such as heat welding and/or adhesive, preferably heat welding. However, in another configuration, the joins could be located other than at the side edges, or there would be no joins when the bag as a whole is made tubular.

Base plate 903 includes a transverse pleat bounded by first folds 909' and 909" and second fold 990. The transverse pleat has leaves or flaps 906a and 906b each having two mitered edges 907. Mitered edges 907 are mitered seals that include a seal line extending from each end of the second crease 990 (ie point X) to point Y on the first crease 909', 909". The mitered edge 907 thus forms the border edge of the interior corner of the bag. The sidewalls 904a, 904b are attached to the base plate 903 along these seal lines, which preferably comprise heat welds. As best seen in Figure 14, the second fold 990 and the leaves 906a, 906b are between the side walls 904a, 904b, with the outer surfaces of the leaves 906a, 906b facing each other.

In the illustrated embodiment, the first and second sidewalls 904a, 904b and the base plate 903 are integral, from the shown limit of the sidewall 904a at the closed end to the folds 909', 990 and 909", And there are no intermediate connections in the path to the shown limit of the side wall 904b at the closed end of the bag.

In a less preferred configuration, sidewalls 904a and 904b may not be integral, and the above-defined path may be interrupted by a connection formed along fold line 990 or along or adjacent fold lines 909', 909".

When the bag is in the flat condition shown at 13 and 14, the mitered edge 907 preferably forms an angle between 30° and 60° relative to the second crease 990, most preferably at 45°.

Figure 15 shows a bag partially similar to that shown in Figures 1 and 2, but actually fully open to contain or prepare to receive a product. The side walls 904a, 904b no longer lie substantially flat together as in FIGS. 13 and 14 , but are separated from each other. In the illustrated embodiment, side edges 904a and 904b are joined together along side edges 905a and 905b. The connection is preferably a heat weld along the entire length of the side edges 905a, 905b, although other connection means may alternatively or additionally be used, such as the use of adhesives.

The upper edges of the side walls 904a, 904b will form the closed ends of the bag, details of construction not shown for clarity. The substantially rectangular base 908 (which is part of the base plate 903) that allows the bag to be placed in an upright position is bounded by fold lines 909', 909" and 910', 910", and is formed by opening the panels in Figures 13 and 14. leaves 906a, 906b. The beveled edge 907 now lies above a horizontal plane, although filling of the bag may cause the beveled edge 907 to deviate further from the vertical plane. But preferably oriented towards a vertical plane, the beveled edge 907 and the fold lines 910', 910" define upstanding substantially rectangular end wall portions 911a, 911b. The fold lines 910', 910" form the base sides of the portions 911a, 911b , while the mitered edge 907 at point X forms the remaining sides with the vertices of the triangle. Thus, in the illustrated embodiment, the apexes of the triangular-shaped end wall portions 911a, 911b lie above the base 908 in use. Portions 911 a , 911 b are formed by opening the leaves 906 a , 906 b and include end regions of the base plate 903 . Preferably, the mitered edge 907 forms an angle between 30° and 60° relative to the fold lines 910', 910". Additional reinforcement (such as reinforcement welding or bonded reinforcement tabs) can be provided where desired, such as point X , at which point the weld of the beveled edge 907 merges with the weld of the margin edges 905a, 905b.

The mitered corner 912 formed by the mitered edge 907 and shown in dotted lines in Figure 13 can be eliminated if improved loading is desired, but is not critical. If not removed, in the bag shown in Figure 15, portion 912 simply forms an additional triangular layer (not shown) above point Y-X-Y.

Thus, by means of this embodiment of the invention, it is possible to provide a bag which can stand stably in an upright position, which is suitable for loading heavy and loose materials, and which can be manufactured easily and at low cost in an automated process, and which provides excellent loading performance.

This variation of the invention provides a bag with an easy-open closure and a stable, flat base. This type of bag is especially suitable for the transportation of semi-finished food in the factory or finished food between the factory and the retail point. An example of a completed bag of this type is shown in FIGS. 16 , 17 and 18 . Other suitable uses will be apparent to those skilled in the art. Features identical or similar to those shown in Figs. 13, 14 and 15 will not be specifically pointed out and described in detail.

Crucially, the bag of this embodiment of the invention combines a stable flat base with the same or similar easy-open closure described above, and also provides an area by which the bag can be sealed after filling without affecting the Easy-open closure.

Referring now to Figures 16 and 17a, bag 500 incorporates a flat, stable base 508, preferably constructed as described in connection with Figures 13, 14 and 15. The bag has a bag portion 500A comprising a first side wall 501 and a second side wall 502 . A closure piece is attached to the first side wall 501 to form a closure over the mouth 521 . The second side wall 502 has an extension 553 above the bag portion 500A so the mouth is bounded by the end edge 509 of the first side wall 501 in combination with the inner surface 502A of the second side wall 502 . The closure flap 505 is attached to the first side wall 501 in any of the ways described above, allowing it, or a portion thereof, to be removed to reveal the opening 521 and to keep the first side wall 501 functionally intact. Thus, the closure flap 505 may be attached to the first side wall 501 by a peelable adhesive, as in the first aspect of the invention, or without a peelable adhesive, as in the second aspect of the invention. Optimally, the closure flap 505 is attached by a peelable adhesive 515 . The closure flap 505 is preferably tearable along a line of weakness 516, which is most preferably in the form of a perforation. The bag of this embodiment also has a flap 528 located at the border of the mouth 521, the flap 528 being functionally equivalent to the flap 208 of the previous embodiment.

In the embodiment shown in FIGS. 17A-C , the bag is closed by a closable region 550 . Actual closure by any suitable means 551 is effective, such as adhesive or heat sealing. In the embodiment shown in FIG. 17A , the closable region is formed by the end 552 of the closure flap 505 and the extension 553 of the second side wall 502 . Extension 553 extends over bag portion 500A and is optimally integral with second side wall 502 .

When using the bag, the closable area 550 is opened first to allow the bag to be filled. When the desired contents have been placed in the bag, the closable area 550 is closed by suitable means 551 . When it is desired to access the contents of the bag, the closure flap 505 or the portion 519 (in the embodiment shown) is lifted to expose the mouth, thereby dispensing the contents.

Other configurations of the closable region are also possible. For example, the first and second side walls 501 , 502 may be the same length, so the extension 553 will not be present. In this case, the mouth 521 forms a slit or cutout in the first side wall 501 and the closure flap 505 overlies the slit or cutout. The closable region is thus formed by the first side wall 501 , the second side wall 502 and the end of the closure flap 505 . This structure is shown in Figure 17B. In another variation shown in Figure 17C, the slit or cutout forming the mouth 521 is further from the ends of the side walls 501, 502 (ie closer to the portion 508). In this case the closure flap 505 is also farther from said ends 509 , 510 of the side walls 501 , 502 and does not need to overlie said ends. The sealable region 550 only includes the end regions of the side walls 501 , 502 . In this variant, the closure sheet 505 must be attached to the first side wall 501 on both sides of the slit, a portion on at least one side being peelable or removable to expose the slit while making the first side wall 501 Keep it functionally intact. In this variation shown in FIG. 17C , the closure flap 505 is releasably attached by a peelable adhesive 515 and permanently attached by suitable means at 554 .

Another variation of the bag of this embodiment is shown in FIG. 18 . The bag differs from that shown in FIG. 17 only in that a handle 560 is provided. These handles are perforated, cut or otherwise formed towards the top of the bag, preferably just above the closable area 550 . Alternatively, separate handles may be attached to the bag or adjacent to the closable area.

The method of manufacturing the bag according to the present invention will now be briefly described, but it should be noted that the bag of the present invention is not limited to these methods.

First, referring to FIG. 19 in detail, the manufacturing method of the bag shown in FIG. 1 to FIG. 12 will be briefly described. A sheet of plastic film 600 is extruded and folded at 601 into the structure shown in Figure 19A. An optional second crease 602 is then made, which will ultimately provide the optional second sheet 208 (FIGS. 2, 7, 8) (FIG. 19B). One or more areas 603 of peelable adhesive (eg, hot melt adhesive) are then applied to the surface of the bag (FIG. 19C) and form perforations 604 that provide lines of weakness 216 (FIGS. 3, 4, 5, 6). (FIG. 19D). Portion 605 of sheet 600 is then folded and bonded by peelable adhesive 603 (FIG. 19E). The sheet 600 is cut near the first crease 601 to provide an open end 606 of the bag through which the bag can eventually be filled (FIG. 19F). Finally the sheet is divided into bags of appropriate width and heat seals (or other seals) are formed on the sides to obtain the final bags.

The method of manufacturing the bag according to Figures 16, 17 and 18 will now be described. In the first method, as shown in FIG. 20, sheet 700 is first folded at crease 701 (FIG. 20A). A cross fold 702 is then formed at the crease 701 (FIG. 20B) and a miter seal 703 is formed at the corner of the cross fold portion (FIG. 20C). A portion 704 (shown in dashed lines) of the sheet 700 is then removed (FIG. 20D), and a peelable adhesive 705 is applied to the surface of the sheet 700 (FIG. 20E). An additional sheet 706 with lines of weakness 716 is then applied over the peelable adhesive and overlays the sheet area 707 (FIG. 20F). Finally the sheet is divided and the resulting side edges closed (eg by heat sealing) to form the final bag. Portions 706 and 707 provide a closable region 708 (FIG. 20G).

In addition, a suboptimal method is shown in FIG. 21, and the steps shown in FIGS. 21A to 21E are the same or similar to those shown in FIGS. 20A to 20E. In the step shown in FIG. 21F , perforation 709 (which forms line of weakness 216 ) is formed in portion 707 and then portion 707 is folded at crease 710 ( FIG. 21G ) and adhered to peelable adhesive 705 . Sheet 700 is then cut in the area of crease 710 to provide the opening of the bag (FIG. 21H). Crease 710 is spaced from the end of sheet 700 at 711 to create a closable region 712 after crease 710 has been cut. The sheet is then split and the side edges are sealed as previously described in connection with Figure 20G.

In Fig. 22, a method of making a bag similar to that shown in Figs. 1 to 12 is shown. For this bag, the mouth is at a distance from the end of the bag, but the method is also applicable where the mouth is closer to the end of the bag.

Referring now to Figure 22, a sheet of plastic film 750 is extruded and folded at creases 751 and 752 into the structure shown in Figure 22A. In Figure 22A, the spacing of the end edges 753, 754 of the sheet 750 is exaggerated for clarity. An optional third crease to form an optional second flap overhanging edge 753 or 754 is also included. This second sheet is similar in construction and operation to the second sheet overhanging fold 602 in FIG. 19 .

Next, one or more areas of peelable adhesive 755 (eg, hot melt adhesive) are applied to the surface of the bag. Adhesive 756, which may be peelable or permanent, will also be applied on the other side of gap 757 (FIG. 22B). An additional sheet 758 is then applied over the adhesive areas 755 , 756 to cover (and close) the gap 757 . The additional sheet has a line of weakness 759 (FIG. 22C). Finally, the sheet 750 is split to form individual bags and one side 760 is sealed by heat sealing or adhesive (FIG. 22D). The other end 761 is open for filling the bag, after which the bag can be closed at area 762 (FIG. 22E). In another variation, after the step shown in FIG. 22C, the sheet 750 may be divided as shown in FIG. 22D to form individual bags, with both rear side edges 761 and 763 sealed, such as by adhesive or heat sealing. In this variation, crease 752 may be cut away (either before or after sheet 750 is severed) in order to provide access to the bag for filling. The ends may be closed after filling the bag, for example by heat sealing or adhesive.

Figure 23 shows another variant of the bag of the invention, in which the mouth is at a distance from the end of the bag. Referring to Figure 23, the bag 560 has a flat, stable base 508, preferably constructed as described with reference to Figures 13-15, and with reference to Figures 16 and 17. The bag 560 also has a closable region 550 which, after filling the bag, can be closed in any of the ways described above. The mouth 521 of the bag 560 is in the same form as the slit or gap 562 . The mouth 521 is closed by a closure flap 565 covering the gap 562 . The closure flap is attached to the front surface 561 of the bag by one area of releasable adhesive 563 and on the other side of the gap 562 by an area of releasable or permanent adhesive 564 . The closure flap has a line of weakness 566 along which the closure flap 565 can be torn open so that a portion 569 can be uncovered to expose the mouth 521 through the area of the peelable adhesive 563 .

FIG. 24 shows one method for making the bag shown in FIG. 23 . In this method, a sheet of plastic film 770 is extruded and folded at creases 771 and 772 into the structure shown in Figure 24A. In FIG. 24A, the spacing of the end edges 773, 774 of the tab 770 is exaggerated for clarity. An optional third crease to form an optional second flap overhanging edge 753 or 754 is also included. This second sheet is similar in structure and operation to the second sheet suspended over crease 602 in FIG. 19 .

Thereafter, a cross fold 775 is formed at the crease 771 (FIG. 24B) and a miter seal 776 is formed at the corner of the cross fold portion (FIG. 24C). Next, the crease 772 is cut away to provide an end 776 for opening the bag for filling (FIG. 24D). One or more areas of peelable adhesive 777 are applied to the bag adjacent to the gap 778 and an adhesive area 779 is also applied on the other side of the gap 778 . Adhesive area 779 may be peelable or non-peelable. The positions of the adhesive regions 777 and 779 can be reversed if desired (FIG. 24E). An additional sheet 780 with lines of weakness 781 is then applied over the bonded areas 777, 779 to cover (and close) the gap 778 (Fig. 24F). Finally, the sheet 770 is split to form individual bags and the side edges are sealed by heat sealing or adhesive. After the bag is filled, the open end 776 is closed by suitable means in the closable region 782 .

Claims (36)

1. plastic bag, it comprises:

Form first and second sidewalls of bag section together with front and rear surfaces;

The front surface that is formed on sack is in order to enter oral area of sack in-to-in; And

Cover the also closure plate of closed oral area, this closure plate has a zone that strippingly is connected on the front surface;

At least a portion of crossing strippable join domain peelable closure plate from the front surface to be exposing oral area, and front surface keeps complete on the function.

2. plastic bag as claimed in claim 1, it is characterized in that: at least one line of weakness that this part of the closure plate that can peel off from front surface is extended by peelable join domain defines, along the peelable closure plate of this line of weakness to expose the oral area of sack.

3. plastic bag, it comprises:

Form first and second sidewalls of bag section together with front and rear surfaces;

The front surface that is formed on sack is in order to enter oral area of sack in-to-in;

And covering the also closure plate of closed oral area, this closure plate has a zone that is connected on the front surface;

Wherein this closure plate has at least one line of weakness that has defined its part, and this part of closure plate does not comprise any part that is connected to the zone on the front surface, can open this part to expose the oral area of sack by tearing along line of weakness.

4. as claim 1,2 or 3 described plastic bags, it is characterized in that: this closure plate has the line of weakness of an arc, and this line of weakness is extended from all end edge towards closure plate of proximate mouth on the closure plate.

5. as the described plastic bag of arbitrary claim in the claim 2 to 4, it is characterized in that: have and be formed on the finger-hole of at least one on the line of weakness in the closure plate, can clamp closure plate by this finger-hole and tear.

6. as claim 1,2 or 3 described plastic bags, it is characterized in that: at least two line of weakness that described part is closed in the sheet define, and can tear closure plate to expose the oral area of sack along line of weakness.

7. plastic bag as claimed in claim 6 is characterized in that: line of weakness terminates in the one or more finger-holes that are formed in the closure plate, can clamp closure plate by finger-hole and tear.

8. plastic bag as claimed in claim 6 is characterized in that: line of weakness extends to all points of proximate mouth from the end edge of closure plate.

9. as claim 1, the 2 described plastic bag of arbitrary claim in the claim 4 to 8 when being attached to claim 1 or 2 maybe, it is characterized in that: this part of strippable closure plate is connected in front surface by releasable adhesive.

10. as claim 1, the 2 described plastic bag of arbitrary claim in the claim 4 to 8 when being attached to claim 1 or 2 maybe, it is characterized in that: this part of strippable closure plate is connected in front surface by strippable thermal welding or strippable heat-seal areas.

11. as the described plastic bag of arbitrary claim in the claim 2 to 10, it is characterized in that: line of weakness is formed in the eyelet in the closure plate.

12. as the described plastic bag of above arbitrary claim, it is characterized in that: comprise a closeable zone at the first end place that is formed on sack, this zone is in order to seal sack after filling.

13. as the described plastic bag of above arbitrary claim, it is characterized in that: the first side wall forms the front portion of sack, and second sidewall forms the rear portion of sack; Described sidewall has identical length.

14. plastic bag as claimed in claim 13 is characterized in that: this oral area comprises a slit that is formed in the front surface.

15. plastic bag as claimed in claim 13 is characterized in that: also comprise a line of weakness that is formed in the front surface, this line of weakness is disconnected to form oral area.

16. as the described plastic bag of arbitrary claim in the claim 13 to 15, it is characterized in that: this closeable zone comprises the end of first and second sidewalls.

17. plastic bag as claimed in claim 16 is characterized in that: this closeable zone also comprises an end of closure plate.

18. as the described plastic bag of arbitrary claim in the claim 1 to 12, it is characterized in that: the first side wall forms the front portion of sack, and second sidewall forms the rear portion of sack, and wherein second sidewall has an extendible portion that is positioned on the bag section.

19. plastic bag as claimed in claim 18 is characterized in that: this closure plate covers the part of the first side wall and the described extendible portion of second sidewall.

20. plastic bag as claimed in claim 19 is characterized in that: this oral area is defined by the end edge of the first side wall.

21. as claim 19 or 20 described plastic bags, it is characterized in that: this closeable zone comprises an end of the extendible portion and the closure plate of second sidewall.

22., it is characterized in that: also comprise by means of the border folding line being suspended on the edge of oral area and extending in the sack inside one second as the described plastic bag of arbitrary claim in the claim 1 to 21.

23. plastic bag as claimed in claim 22 is characterized in that: this second can be connected on second inside surface of side wall by adhesives.

24. plastic bag as claimed in claim 23 is characterized in that: described adhesives is a releasable adhesive.

25. as the described plastic bag of arbitrary claim in the claim 1,2 or 4 to 24, it is characterized in that: on the part of strippable closure plate, any paths that extends to away from the described portion boundary of described oral area from the most described portion boundary of close oral area must pass strippable join domain.

26. as the described plastic bag of arbitrary claim in the claim 4 to 25, it is characterized in that: and path proximate mouth parallel along the first side wall is in the strippable join domain fully, is at least within the peelable part of closure plate.

27., it is characterized in that as the described plastic bag of arbitrary claim in the claim 12 to 26: but also comprise a base portion that is formed on away from the place, end of the sack of enclosed region, can make the stable flat site of standing of sack to be provided with.

28. sack as claimed in claim 27 is characterized in that: this base portion comprises:

Be connected to a substrate of first and second sidewalls by first folding line along its opposite side, this substrate also has one second folding line, second folding line extends with the width of described sidewall and is parallel to first folding line, second folding line is divided into the first and second plate leaves with substrate, second folding line and plate leaf are between the described sidewall, and the outside face of plate leaf faces with each other; And

Comprise the mitered sealing of a sealing lines, the sealing line extends to each first folding line from each end of second folding line, and first and second sidewalls are connected to substrate along the sealing line.

29. plastic bag as claimed in claim 27 is characterized in that: this base portion comprises the substrate of a rectangle, and this substrate has relative lateral edges and relative end edge; And leg-of-mutton all end wall portion, each end wall portion is suspended on each end edge of substrate along its basic side, this substrate is connected to first and second sidewalls by first folding line consistent with described each lateral edges, described leg-of-mutton end wall portion has the tip that is positioned at when using on the described substrate, and has a lateral edges that comprises potted line, potted line extends between each bight of described tip and described base portion, and first and second sidewalls are connected to described end wall portion along potted line.

30. plastic bag as claimed in claim 28 is characterized in that: mitered leak free potted line comprises thermal welding.

31., it is characterized in that: an angle between relative second folding line of mitered leak free potted line forms 30 ° and 60 ° as claim 28 or 30 described plastic bags.

32. plastic bag as claimed in claim 31 is characterized in that: the relative second folding line shape of mitered leak free potted line angle at 45.

33. plastic bag as claimed in claim 13 is characterized in that: this oral area is defined by the end edge of the first side wall.

34. as the described plastic bag of arbitrary claim in claim 1 to 15 or 33, it is characterized in that: this closure plate is suspended on second sidewall.

35. plastic bag as claimed in claim 34 is characterized in that: this closure plate and second sidewall form one, and are suspended on second sidewall along a folding line.

36. as the described plastic bag of arbitrary claim in the claim 1 to 26, it is characterized in that: this sack also is provided with the 3rd that covers and strippingly be connected in first or second sidewall, the 3rd the end away from the sack of closure plate be suspended in second or the first side wall on.

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