DE29521183U1 - Rectangular base container - Google Patents

Description

U. Z: A 2039 GM-DE/D
ATIFON Corporation

RECTANGULAR BASE CONTAINER

The present invention relates to a container with a rectangular base,

By using the

The term "container" refers to a container made from sheets or foils of flexible material.

which is formed into a suitable shape useful for containing individual pieces, powdered or granulated material or liquids.

Containers with which the present invention is concerned are a practical, inexpensive means for packaging goods and are thus widely used in the food industry, but are not limited to this field. The main advantages of such containers are that they are easy to manufacture, inexpensive and usually suitable for storing a variety of products.

Such containers take up minimal space during storage and can be easily disposed of.

The most commonly used form of container is the so-called "bag", which is a sheet of material such as paper, cardboard, plastic or a laminate shaped like a bag or sack.

In some cases, bags are formed in one piece with a base. However, such bags cannot stand on their own and require the internal pressure of their contents for stability. Furthermore, such bags are usually oval and thus are less stable and also require more storage space. Yet another disadvantage is that the structure of such products is not solid and thus they can collapse if not completely filled.

In the present description and claims, the terms "heat-weldable material" or "heat-weldable surface" are used to refer to layers of plastic material, e.g. polyethylene, polypropylene, etc., which can melt when heated and then adhere to further such layers by a process hereinafter referred to in the description as "welding". The term "heat welding" is also referred to in the art as "heat sealing".

Typical containers are made from a single sheet that is folded into a container shape with overlapping sections that are then glued or welded together. Such containers are usually not suitable for holding liquids and do not have a rigid structure so that they collapse when their contents are partially removed. Furthermore, containers made by the methods known to date are usually limited to bag-shaped or prismatic box-shaped containers.

It is an object of the present invention to provide a new and improved container

which substantially reduces or overcomes the aforementioned disadvantages.

According to the invention there is provided a container which consists essentially of one or more sheets of film; the container having a lower base and walls extending upwardly therefrom; the base being essentially rectangular and forming front, rear and two side sections of the walls; the base consisting of a film, both of which
sides are heat-sealable, and the walls consist of a film with at least one inner heat-sealable side; the container is constructed from a bag with a front, back and bottom sheet; the bottom sheet of the bag is folded along its centerline with flaps extending downwards from the fold line and each of the two lower

edges of the flaps are welded to or integrally formed with a lower edge of either the front or rear sheets, lateral edges of the front and rear sheets are welded together, the two lower portions of the welded edges enclosing both lateral edges of the folded bottom sheet therebetween; for constructing the container, a central portion of the bottom sheet is unfolded so that the unfolded portion has a substantially rectangular shape and thus forms the base, central portions of the lower edges of the bottom sheet forming the front and rear edges of the base and peripheral portions of the bottom sheet forming two overlapping triangular portions, the lower edges of which form the two side edges of the rectangular base, and thereby ^forming the front and rear wall portions of the container extending from the front and rear edges and ^the side walls extending from the side edges, the welded edges of the two sheets lying approximately above the centerline of the side walls; the structure is secured by welding the two overlapping triangular sections together or by welding a peripheral triangular section of the two overlapping sections to an adjacent inner surface of the side arches.

According to one embodiment of the present invention, the lower base and walls are made from a one-piece foil sheet, both sides of which are heat-weldable.

In order to give rigidity to the container according to the invention, one or more reinforcing elements made of a heat-weldable material or coated with it are welded onto the lower side of the rectangular base and welded thereto. The reinforcing element can be made up of several segments or can be a one-piece

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frame welded to the inside of the walls near their top or bottom edges.

A reinforcing element welded to the upper part can have a shape and size corresponding to the rectangular base, thus obtaining a rectangular box-shaped container. Alternatively, the reinforcing element can have any other shape and size. If the reinforcing element is a larger rectangle than the base, a truncated square pyramid is obtained, which is suitable for stacking such containers one inside the other.

According to yet another embodiment of the present invention, rigid elongated webs made of or coated with a heat-weldable material are welded along the inner walls of the container to provide rigidity thereto. Alternatively, the webs are formed in one piece with one or more reinforcing elements. These stiffening webs can have various shapes so that the container, when welded to the walls, takes on a shape corresponding to that of the webs.

A procedure

for the manufacture of a container, the container having a substantially rectangular base with walls consisting of front, rear and two side portions extending upwardly therefrom, the base consisting of a film having both sides heat-sealable and the walls consisting of a film having at least one inner heat-sealable side; comprising the steps of:

(a) Making a bag having a front, back and bottom sheet, the bottom sheet being folded along its centerline, with the flaps extending downwards from the fold line and the two lower edges of the flaps each being joined to a lower edge

either the front or rear arch are welded or are formed as one piece therewith, side edges of the front and rear arches are welded together with their lower sections enclosing both side edges of the bottom arch between them;

(b) unfolding a central portion of the floor sheet such that the unfolded portion assumes a rectangular shape and the two peripheral portions form two overlapping triangular portions;

(c) welding the two overlapping triangular sections together or welding a peripheral triangular section of the two sections to the adjacent inner surface of an adjacent arch.

For a better understanding, the invention will now be described by way of example with reference to the accompanying drawings, in which:

Fig. 1 is an isometric exploded view of the components of a basic container according to the invention, arranged according to a first step of its manufacture;

Fig. 2 is an isometric view of an inventive
bag;

Fig. 3 a representation of how the rectangular shape of the base is obtained;

Fig. 4 is a schematic representation of the welding process of the rectangular base;

Fig. 5 is an isometric view of a basic form of a container according to the invention;

Fig. 6 is an exploded isometric view of only a lower portion of a container according to the invention and a reinforcing element;

Fig. 7 is a schematic representation of how the reinforcing frame of Fig. 6 is welded to the rectangular base of the container;

Fig. 8 is an isometric view of a container according to the invention, in which the upper edges of the front and rear walls are welded so as to seal the container;

Fig. 9 is an isometric view of a container according to the invention, in which the upper edges of the side walls are welded so as to seal the container;

Fig. 10 is a side elevation of the container of Fig. 9;

Fig. 11 is an exploded isometric view of only an upper portion of a container according to the invention and a reinforcing frame;

Fig. 12 is an isometric view of a container according to the invention having a shape of an inverted truncated rectangular pyramid;

Fig. 13 is an isometric exploded view of only an upper portion of a container according to the invention, wherein a rectangular reinforcing frame is provided with longitudinal struts extending downwards in one piece ;

Fig. 14 is an isometric exploded view of only an upper portion of a container according to the invention with a rectangular reinforcing frame provided with a box-shaped reinforcing structure;

Fig. 15 is an isometric view of a container according to the invention, in which the upper base is smaller than the rectangular base;

Fig. 16 is an isometric view of a container according to the invention, which is formed with a narrowed central section;

Fig. 17A to 17D are isometric exploded views of various devices for sealing or closing the upper portion of the container;

Fig. 18 is an isometric view of another embodiment of a container according to the invention;

Fig. 19 is an isometric view showing a modification of a container according to the invention;

Fig. 20 is a partial isometric view of a step for obtaining a base according to a modification of the invention;

Fig. 21 is a partial isometric view of the modification as in Fig. 20;

Fig. 22 is a perspective view showing a continuous manufacturing process of a container

shows;

Fig. 23A is a perspective view showing a process for preparing a bag for manufacturing a container according to the present invention;

Fig. 23B to 23G are schematic cross-sections through various stages of the process of Fig. 23A;

Fig. 24A shows a second process for making a bag for producing a container according to the invention;

Fig. 24B to 24D are schematic cross-sections through various stages of the process of Fig. 24A;

Fig. 25A is a perspective view showing the preparation of a bag according to a third process for the manufacture of a container according to the invention;

Fig. 25B to 25D are schematic cross-sections through various stages of the process of Fig. 25A;

Fig. 26A is a perspective view showing the preparation of a bag according to yet another process for manufacturing a container according to the invention; and

Fig. 2 6B to 23E are schematic cross-sections through various stages of the process of Fig. 2 6A.

Reference is now first made to Figures 1 and 2 of the drawings, in which two sheets 1 and 2 of substantially equal size are positioned opposite each other, the opposing surfaces of the sheets being made of or coated with a heat-weldable material such as polyethylene.

A third sheet 3 has the same width as sheets 1 and 2 and is made of a heat-weldable material or is coated with it on both sides. The third sheet 3 is folded and then placed between the two sheets with its lower edges 4 aligned with the lower edges 0 5 of sheets 1 and 2 and the fold line 7 between sheets 1 and 2.

Alternatively, only a single sheet made of a heat-weldable material or coated with it on both sides may be used instead of the three individual sheets 1, 2 and 3, as is readily understood and shown by dashed lines in Fig. 1.

Then the side edges 6 of the sheets 1 and 2 are welded as known per se, whereby the side edges 8 on the folded sheet 3 are enclosed therebetween.

In a second step, the lower edges 5 of the sheets 1 and 2 are welded to the corresponding lower edges 4 of the sheet 3. The welding of the two lower edges 4 to each other is prevented by first

a plate 9 coated with a non-stick material such as Teflon™ or silicone is inserted before the welding process. At the end of this process, a bag, generally designated 11, is formed.

Reference is now made to Figures 3 to 5 which illustrate how the rectangular base is formed. A rectangular core element 15 is provided with elements 16 and 17 which are laterally expandable in two perpendicular axes and coated with a non-stick material. The core 15 is then inserted into the bag 11 until a central portion of the third sheet 3 becomes substantially flat at the bottom of the bag 11, thereby forming a flat rectangular base 20.

As can be seen in Fig. 5, after completion of this step, side walls 18 are formed as well as two overlapping triangular sections 19 formed by the third sheet 3 on each side of the container and which overlap the side walls 18. The elements 16 and 17 of the core element 15 are then spread as can be seen in Fig. 4 so that they fit snugly against the bottom of the bag, pressing the triangular sections 19 against the side walls 18.

In order to fix the rectangular shape of the base, the triangular sections 19 must be welded to the side walls 18. As is known per se, heat is applied to the triangular sections via electric heating pads 21, and if necessary also from heating elements (not shown) within the core 15. After retraction of the expandable elements 16 and 17, the core 15 can be withdrawn from the bag and a self-standing container with a rectangular base according to the present invention is thus obtained.

According to a further embodiment shown in Fig. 6, a heat-weldable material

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or coated therewith, which also has, in the specific embodiment, a rectangular frame shape adapted for welding to the bottom surface of the rectangular base 20 in a manner explained in detail below. As can be seen, the reinforcing element has an inverted L-shaped cross-section for supporting a peripheral portion of the base. Alternatively, it may be provided with reinforcing webs or may be a flat surface.
or even consist of four individual elements arranged at right angles.

Fig. 7 illustrates in schematic form how the reinforcement member 22 is secured to the container base. A first expandable rectangular core 15, as explained with reference to Fig. 4, is inserted into the container and a second similar expandable rectangular core member 15' is positioned beneath the reinforcement member 22. The cores 15 and 15' are then spread and pressed against each other, thereby positioning the reinforcement member relative to the container, where heat is applied via electrical heating pads 21, thereby welding the reinforcement member to the container as previously explained. Heat may also be provided by heating pads integral with the core members 15 and 15'.

Fig. 8 shows an embodiment of sealing the container by welding the upper edges of the front and rear walls 1 and 2. In this way, the container retains its basic rectangular shape.

Fig. 9 and 10 show how the container is sealed by welding the upper edges of the side walls 18, which gives the special shape as can be seen. The dashed line represents a tear line for pouring out liquid.

Referring now to Fig. 11, there is shown an upper rectangular section of a container 11 and a rectangular reinforcing member 25. The reinforcing member 25 is made of or coated with a heat-weldable material and, during assembly, fits snugly into the container flush with the upper edges and is then welded thereto, whereby the upper edge of the container takes the shape of the reinforcing member, becomes solid and does not deform.

It will be apparent, however, that any size and shape of reinforcing member 25 may be used as long as it can be securely welded to the upper edges of the container. It will also be apparent that the reinforcing member may be made of a heat-weldable or coated material as discussed above, or it may be made of metal or other suitable material which may be secured to the container by folding and clamping it over the upper edges of the container, or by other means known per se.

In Fig. 12, a container 11 is formed as already explained, with the sheets 1 and 2 made of a material which can be expanded under the influence of heat, such as polyamide, and coated or laminated with a heat-weldable material. Then an expandable core (not shown) having a cross-section of a rectangular pyramid is fully inserted into the container and expanded until its side plates are pressed against the inner walls of the container. The expanded core is then heated by means of internal heating elements (not shown) to a temperature suitable for plastic deformation of the laminate forming the walls of the container. It is then slowly withdrawn from the container, the cross-section of the core gradually being expanded further, which results in the container taking on the shape of an inverted pyramid.

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sectioned rectangular pyramid as shown in Fig. 12.

Alternatively, the rectangular pyramid shape can be used in a

hot environment rather than applying heat directly to the container, for example in an oven or in a hot air tunnel or a combination of both.

Subsequently, a rectangular reinforcing frame member 25' having a larger projection than the rectangular base 20 is welded to the upper edge of the container as shown in Fig. 12, which provides rigidity to the container.

The container shown in Fig. 12 is suitable for stacking within similar containers of this type, thus reducing the storage space required for such empty containers.

Fig. 13 shows how a reinforcing element 27 made of a heat-weldable or coated material is formed in one piece with four reinforcing struts 28 extending downwards from the corners of the frame. The struts 28 are also made of a heat-weldable or coated material and are essentially as long as the inside length of the container. The frame with the integral struts 28 is inserted into the container 11 and welded to the container by applying heat and pressure thereto by means of a core (not shown) as already explained.

According to a further embodiment of the present invention, which can also be seen in Fig. 13, a second reinforcing frame 30 is arranged in one piece at an opposite end of the struts 28 parallel to the upper reinforcing frame 27, thereby achieving improved rigidity.

Once the struts 28 are welded to the container, the latter is also reinforced in its axial direction,

which means that it retains its rectangular box-shaped form even when it is subjected to impact when empty

Fig. 14 differs from Fig. 13 in that instead of the four struts 28, the reinforcing element 27 is formed in one piece with a box-shaped reinforcing structure made of a material that can be hot-welded or coated therewith and is suitable for insertion into the container 11, resting against the walls of the container. Preferably, the box-shaped reinforcing structure 29 is welded to the walls of the container, but this is not mandatory.

Fig. 15 of the drawings shows a container with tapered walls. After forming the container 11 as previously explained, the straight edges (shown in dashed lines) are reshaped along a concave line 31, which may just as well be straight or another line. The edges are welded along the lines 31 by means of hot pressure plates (not shown) which achieve the tapered shape of the container. The reinforcing frame 32 is then welded to the top of the container as previously explained and the protruding welded flaps 33 may be cut off adjacent to the weld line 31 for better appearance.

Fig. 16 illustrates a container with a narrowing section 36 along the container, wherein a new corner edge 37 is created by pressing and welding corresponding sections of the side walls to the adjacent front and rear walls similar to the embodiment of Fig. 15 and, if necessary, removing protruding sections 36.

Fig. 17 shows some means for sealing or closing the upper portion of the container. In Fig. 17A, a

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or coated therewith, is provided with an outlet 42, the frame 41 being welded or secured to the frame 25 as previously explained. The contents of the container are removed through the outlet 42, which can be closed by means of a suitable closure. In Fig. 17B, an aluminum foil 43 is embedded within a frame 44 made of or coated with a heat-weldable material, which fits snugly within a frame 45. The frame 44 is welded to the frame 45, thereby sealing the container. When the contents of the container are to be used, the aluminum foil 43 is then cut open adjacent the frame 44.
and removed, allowing a suitable plastic lid to be inserted for repeated sealing and closing of the container.

In Fig. 17C, the container is sealed with a lid 46 provided with an outlet 47, whereby the lid 45 is under

Without the use of a reinforcing frame 4 5 welded directly to the container 11 or otherwise attached thereto.

In Fig. 17D, a foil 48 made of aluminum or any other material suitable for sealing, and having a frame 45 formed integrally therewith, without the use of a reinforcing frame 45, is welded directly to the upper edges of the container 11 as in Fig. 17C. It will be apparent that the lid can be secured to the container by any other means known per se.

In Fig. 18, a further embodiment of a container can be seen in which the side walls 18' consist of a substantially flat section 51 and a side-fold section 52 consisting of two overlapping flaps 53 and an intermediate section 54.

Fig. 19 illustrates how the container is made in the form of a jug with a handle portion 56 and a pouring spout 57. The handle portion is made by forming a gusseted portion as in the embodiment of Fig. 18 and welding the overlapping flaps 53' together. An opening 58 is then cut out in each flap 53', the openings serving for gripping the container.

Figures 20 and 21 illustrate the steps of reinforcing the base portion of the container according to another embodiment of the invention. After the container is fully manufactured, as seen in Figure 5, instead of attaching a reinforcing member 22 (as in Figure 6), a slot 60 is cut at each corner of the base skirt 61. Then, the skirt sections are folded inward as shown by arrows 62 and welded to the bottom of the base member 20, making the base rigid and durable.

Attention is now directed to Figs. 22 to 26, which show in schematic form the steps of a process for producing a container according to the invention

which also has filling and sealing devices.

Various manufacturing steps and components of the container are the same as those of Figs. 1 to 5 and accordingly, like elements and components are designated by like reference numerals as the corresponding ones in Figs. 1 to 5 and an additional prime character, and the reader is referred to these above figures for a detailed explanation.

Fig. 22 shows a schematic plan for the manufacture, filling and sealing of a container according to the invention.

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A first step, generally designated 70, produces a bag 11'. Some detailed examples of this step are specified below.

The finished bag 11' then reaches a rotating work station, which is generally designated 72 and has gripping devices 74, which can be, for example, vacuum cushions as known per se. Then, at 76, the bag 11' is pulled apart by a suction device which separates the sheets 1' and 2' from one another.

The next step, indicated at 78, comprises the insertion of an expandable core 80 into the bag and at a station 82 a central portion of the bottom sheet of the bag is unfolded so that the unfolded portion assumes its rectangular shape and the two peripheral portions form two overlapping triangular portions as explained. Finally, two welding pads 84 approach the side of the container and weld the two overlapping triangles to fix the shape of the container as explained above.

Additional work stations may be added to the assembly 72, for example for the addition of reinforcement elements, for a special configuration of the container, etc., as already explained above. The work station 72 then delivers the container to a belt conveyor 86,

which brings the finished container to a filling station for a per se known automatic filling.

The filled containers then travel via the belt conveyor to a sealing device generally designated 90, in which the containers are gripped by suitable arms 92 and introduced into a sealing station 94, in which the containers are sealed, for example, by welding the upper edges as shown in Fig. 8 or by any other suitable sealing device as described with reference to

Fig. 9, 10 and 17 or otherwise sealed.

At the end of this step, the containers are ready for use and are conveyed by a belt conveyor 95 to a packaging station (not shown).

In Figs. 23A to 23G, the first step of the method, generally designated 70, can be seen in which a bag 11' is manufactured.

A first film 100 having a top surface 102 coated with a heat-weldable material is pulled off an unwinding roll 104. At the same time, a second film 106 having both sides coated with a heat-weldable material is pulled off an unwinding roll 108 which is arranged centrally (as shown in Fig. 23C) above the first film 100.

The central portion of the film is then sucked into a notch 109 on an edge of a triangular shaped mold element 110 (better seen in Figures 23B and 23E).

The films positioned by the rollers 112 and 114 pass a blade 116, whereby the films are cut along their bottom edge and the cross-section of the films assumes that shown in Fig. 1 of the drawings.

Two hot rollers 118 are arranged side by side with a non-stick plate (e.g. Teflon™ or silicone) 120 interposed therebetween. As the films pass between the rollers 118, the bottom edges 4' and 5' of the sheets are welded and as the laminate passes between the rollers 122, it is welded by the hot welding bars 124, thereby producing a plurality of connected bags 126, which are then obviously separated by a cutting station 128.

In Figs. 24A to 24D, two sheets 130 and 132, which are provided on their opposite sides with a hot

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weldable material are drawn off from unwinding rolls 134 and 136, respectively. A third sheet 138, both sides of which are heat-weldable, is drawn off from an unwinding roll 140.

Before the opposing sheets 130 and 132 reach each other, the third sheet 138 is folded by a grooved triangular member 142 as explained with reference to Fig. 23B. The folded sheet 138 (forming the bottom sheet) and the sheets 130 and 132 (forming the walls) then pass between positioning rollers 144 and 146 and their lower edges are welded by welding rollers 148 with a non-weldable plate 150 inserted therebetween as already explained.

The laminate is then welded by welding webs 152 of rollers 154, thereby forming the side edges of the bags. Finally, the bags 126' are separated from one another, as already explained above.

Figures 25A through 25D illustrate a process substantially similar to that of Figures 24A through 24D, except that a reclosable zipper-like strip 136 is welded to the upper edges of the bag by means of welding rollers 158 and a non-welding plate 160 inserted between the sheets. The bags and containers subsequently made by this process can thus be opened and closed many times as can be seen.

Figures 26A to 26E illustrate how a bag useful for manufacturing a container according to the invention can be made from a single sheet 162, both sides of which are heat-sealable and which is drawn off from a supply roll 164. The sheet of film 162 passes between a block element 166 with a substantially W-shaped cross section 168 and a sliding element 168 with a triangular cross section, which gradually bends the film into a

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shape as shown in Fig. 26B and 26C, so that when the film reaches the positioning rollers 170, it has already reached the configuration shown in Fig. 1 (with the dashed line). From here on, the process proceeds as already explained with reference to Fig. 23 to 25.

It should be obvious to a person skilled in the art that any combination of the above embodiments can be implemented with appropriate modifications.

Claims (16)

-20- u.Z: A 2039 GM-DE/D ATIFON Corporation Protection claims 1. A container consisting essentially of one or more sheets of film, the container having a lower base and walls extending upwardly therefrom; the base is essentially rectangular and forms front, back and two side sections of the walls; the base consists of a film, both sides of which are heat-sealable, and the walls consist of a film with at least one inner heat-sealable side; the container is constructed from a bag with a front, back and bottom sheet; the bottom sheet of the bag is folded along its center line, with flaps extending downward from the fold line and each of the two lower edges of the flaps being welded to a lower edge of either the front or back sheet or being formed integrally therewith, lateral edges of the front and back sheets being welded together, the two lower sections of the welded edges enclosing both lateral edges of the folded bottom sheet between them; for the construction of the container, a central portion of the bottom sheet is unfolded so that the unfolded portion has a substantially rectangular shape and thus forms the base, central parts of the lower edges of the bottom sheet forming the front and rear edges of the base and peripheral portions of the bottom sheet forming two overlapping triangular portions, the lower edges of which form the two side edges of the rectangular base, thereby forming the front and rear wall portions of the container extending from the front and rear edges and the side walls extending from the side edges, the welded edges -21- of the two arches lie approximately above the centre line of the side walls; the structure is fixed by welding the two overlapping triangular sections together or by welding a peripheral triangular section of the two overlapping sections to an adjacent inner surface of the side arches. 2. A container according to claim 1, wherein the lower base and the walls are made from a one-piece film sheet, both sides of which are heat-sealable. 3. A container according to claim 1, wherein one or more reinforcing elements made of or coated with a heat-weldable material are welded to a lower side of the base. 4. A container according to claim 1, wherein the upper portion of the container is sealed or closed either by welding the upper edge of the front wall to the upper edge of the rear wall or by welding the upper edge of the side walls together. 5. Container according to claim A ₁ , wherein the upper portion is provided with a closure for multiple closing and opening operations. 6. A container according to claim 1, which has a reinforcing element attached to the upper edges of the walls. 7. A container according to claim 6, wherein the reinforcing element is adapted to receive a sealing or closure arrangement. 8. A container according to claim 6, which comprises welding a reinforcing element made of or coated with a heat-weldable material to the walls of the container. 9. A container according to claim 6, wherein the reinforcing element has a projection different from the rectangular base. -22- ' 10. The container of claim 6, wherein the reinforcing frame is substantially larger than the rectangular base, whereby the container tapers inwardly toward the base. 11. A container according to claim 1, which comprises substantially rigid longitudinal struts made of or coated with a heat-weldable material which are welded to the walls of the container. 12. A container according to claim 11, wherein the longitudinal struts protrude from a reinforcing element welded to the lower or upper portion of the container, and the struts have substantially the entire length of the container. 13. A container according to claim 11, wherein the longitudinal struts are curved or corrugated, whereby the walls take the shape of the struts. 14. A container according to claim 1, which comprises a reinforcement with a box-shaped stiffening structure which is welded into the container. 15. A container according to claim 1, wherein one wall portion is shaped to form a handle and the opposite wall portion is formed with a pouring spout. 16. A container according to claim 1, wherein a skirt formed by the welding of the walls and lower edges is folded over the bottom side of the lower base and welded thereto.