Thermoformable packaging container

Abstract: The invention relates to a packaging container (1) manufactured from thermoformable plastic and wholly recyclable. The packaging container (1) consists partly of a thermoformed hollow body (2) and partly of a thermoformed part (3) which covers the opening of the hollow body. The hollow body (2) is provided in its upper plane (4) with an opening arrangement (10). The upper plane (4) makes an angle which is larger than 90° with the front plane (5) and the bottom plane makes an angle which is less than 90° with the front plane (5). The front plane (5) makes an angle with both of the side planes (7,8) each larger than 90°.

Description: The invention relates to thermally formed packaging containers comprising a container part, a closure part and an opening arrangement according to the opening part of claim 1 and a unit of such packaging containers. Packaging containers of this type are described by US-A-5 014 500. The packaging of this type comprises a container part comprising a bottom wall and four side walls and a closure part which covers the open surface of the container part and reaches by sufficiently wide rims over the side walls of the container part. The closure part needs a sufficient stiffness in order to enable said rim to be used as a supporting means because it has to keep the up-standing container part of the final container in the upright position. The closure part also serves as an opening arrangement. In order to open the final (filled and closed) container it is necessary to release said closure part from the container part. Furthermore, GB-A-1 405 019 describes a packaging container wherein the bottom wall of the container part is used as the bottom plane of the final container. The closure part also comprises the opening arrangement. In order to stiffen the thin side walls of the container part at least some of the walls are corrugated. In the packaging industry which produces single-use disposable packages for foods such as milk or juice, the aim is to produce a package which is simple to manufacture and which is made from economical material. The package should further be recyclable at least for the greater part. Thermally formed liquid packages are previously known in the art by making a deep drawn hollow body which is often conical according to e.g. GB-A-1 405 019. These conical hollow bodies are mostly prefabricated and thereafter stacked in one another prior to being filled. The thermoformed packages may be manufactured from different thermoformable plastics such as polypropylene. Polypropylene with a filler is an excellent material since it imparts greater rigidity to the package. The filler may consist of, for instance, lime, mica, kaolin or chalk. An object of the present invention is to facilitate forming, filling, closing and emptying of a packaging container of the type mentioned above. Its opening before closing should also form the major defining surface of the hollow container part. The invention is defined in claim 1. The packaging container can be filled rapidly, and it is possible to work with a smaller deep drawing relationship between processed surface and drawing depth, since the deep drawn part need not be made so deep in order to achieve the desired hollow body volume. Furthermore, the large opening of the hollow body (that means the container part) entails that there will be obtained a long, continuous seal with double material thickness around the largest circumference of the package, which rigidifies the package and moreover makes it easier to handle for the consumer, since the rigidifying frame which forms the seal at the same time constitutes a gripping edge when the package is to be used. Preferred features of the invention are defined in the appended subclaims. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS One preferred embodiment of the present invention will now be described in greater detail hereinbelow, with particular reference to the accompanying Drawings. In the accompanying Drawings: Fig. 1 shows one preferred embodiment of the packaging container; Fig. 2 shows a part of a package; Fig. 3 shows another part of the package; Figs. 4 A-C show details from different embodiments of the joint between the two parts of the package; and Fig. 5 shows another preferred embodiment of the container. DESCRIPTION OF PREFERRED EMBODIMENT A packaging container 1 according to Fig. 1 is manufactured from a material which must be thermoformable, since at least one part of the packaging container is deep drawn to form a hollow body 2. Furthermore, it is desirable that the material is economical to use and it should, moreover, be recyclable to one hundred percent. In this instance, it has been found that polypropylene with an extender or filler which rigidifies the packaging container 1 is an excellent packaging material. The filler may, for instance, consist of lime or chalk which may be added to the plastic material in a quantity of up to between 60 and 70 weight percent of the finished packaging material. A second packaging container part 3 is thermoformed in the same material. The two parts of the packaging container 2 and 3 according to Figs. 2 and 3 may be prefabricated before filling and delivered to a dairy or juice factory stacked in one another. The hollow body 2 according to Fig. 2 is deep drawn from a thermoformable material, but it may also be injection moulded. It is also conceivable to supply the intended packaging material in rolls to the dairy where forming by means of deep drawing or vacuum forming takes place before filling of the packaging containers 1. The hollow body 2 which constitutes the one part of the packaging container 1 as shown in Fig. 2, consists of five planes 4, 5, 6, 7 and 8 and, as a result of the positional relationship between these planes 4, 5, 6, 7 and 8, they will obtain a favourable release angle so that the parts 2 may be stacked and easily drawn out from the stack on filling. Alternatively, the parts 2 may be turned the same direction in the stack or be turned through 180° between each part 2. The hollow body 2 is drawn obliquely out of the stack at an obtuse angle between the top plane 4 of the packaging container 1 and its front plane 5. The opening surface of the hollow body 2 is not parallel with the front plane 5 of the package and makes an angle of less than 90° with all other planes 4, 6, 7 and 8 of the packaging part 2. The front plane 5 makes an angle which is larger than 90° with the top plane 4 and an angle which is less than 90° with the bottom plane 6 of the packaging container 1. The front plane 5 makes an angle of more than 90° in relation to both of the side planes 7 and 8 of the packaging container 1. This gives the hollow body 2 a bathtub like appearance and this hereby achieves the above-described advantages on stacking of the part 2. The front plane 5 can be level as in Fig. 1 or curved as in Fig. 5. The hollow body according to Fig. 2 is provided with an opening hole 9 in the top plane 4. This opening hole 9 is provided with an opening arrangement 10 which may be designed in different manners, but it is desirable that the opening arrangement 10 can be reclosable after being opened for the first time. Furthermore, it is conceivable that an opening arrangement is thermoformed on, or in connection with the deep drawing of the hollow body 2. This thermoformed opening arrangement may, for example, be provided with a conventional screw cap. On filling of the packaging container 1, the opening arrangement 10 is disposed sealed in place in the hole 9, and the packaging container 1 is suitably filled in that the hollow body 2 is oriented with its open portion facing upwards, whereafter the hollow body is filled with the intended contents. The open portion of the hollow body 2 is covered in the finished, filled package 1 by the second package container part 3. On filling of the packaging containers, a plurality of packaging container parts 2 may be connected together so that they are filled simultaneously and thereafter covered by a common covering panel which forms the rear plane 11 for each of the packaging containers 1. Only at a later operational stage are the united packaging containers 1 separated to form individual packages 1. The ready-filled hollow body 2 is covered with the packaging container part 3 according to Fig. 3, which will constitute the rear plane 11 of the packaging container 1. The container part 3 is provided with a flange 12 around the outer defining line of the plane 11 and, inside this flange 12, there is disposed a depression or channel 13. The flange 12 and the channel 13, whose outer edge fits in the opening of the hollow body 2, makes it possible for the container part 3 to remain in the intended position after insertion in the hollow body 2, which facilitates the welding operation of the flange 12 of the container part 3 against a corresponding flange 15 around the opening of the hollow body 2. The depression or channel 13 may serve as a back-up surface in the same process, or make possible the application of a back-up tool for forming a joint where the one joint portion consists of the outer wall section of the depression 13. Figs. 4 A-C show different embodiments of the flange 12 and the depression 13. In Fig. 4C, the flange 12 is angled towards the rear plane 11, with the result that any sealing fin directly projecting from the support surface of the package 1, the bottom plane 6, will be avoided. In Fig. 4A there is no flange 12 on the package part 3, but instead the rear plane 11 is fitted exactly into the opening of the thermoformed hollow body 2. However, this version requires considerable precision in securing the different package parts 2 and 3. The two package container parts 2 and 3 are provided with rigidifying beads 14 which are placed approximately centrally on the finished package 1 as shown in Fig. 1, with a level front plane 5. In addition to rigidification, these beads 14 also provide an improved gripping surface when the consumer handles the package 1 and pours out its contents. The other embodiment of the invention as shown in Fig. 5 has concave depressions 15 on each of the side planes 7 and 8, the depression serving as gripping surfaces. Of course, the level or the curved front plane 5 can be combined either with beads 14 or depressions 15. As will have been apparent from the foregoing description, the present invention realises a single-use disposable package which is recyclable to one hundred percent, since it is manufactured from one and the same material. Because of the long rigidifying sealing fin which extends along the largest wall side of the package, the package is very firm to grip, even though the packaging material is thin and the package itself is simple and economical to manufacture. Because of the design of the deep drawn part, the prefabricated parts can quite simply be stacked together and quite simply drawn out of the stack on filling and finishing of the packaging container.

Claims: Thermally formed packaging container (1) having a front plane (5), two side planes (7, 8), a top plane (4), a bottom plane (6) and an opening arrangement (10), said packaging container comprising a container part (2), one sidewall thereof forming said bottom plane (6) and another sidewall thereof forming said top plane (4), a bottom wall of said container part (2) forming an angle of less than 90° with one sidewall and an angle of more than 90° with another sidewall, said packaging container comprising furthermore a closure part (3) covering the open surface of said container part (2), characterized in that said bottom wall of said container part (2) forms said front plane (5) forming an angle of less than 90° with said bottom plane (6) and an angle of more than 90° with said top plane (4) and in that one wall of said container part (2) comprises said opening arrangement (10) for opening the packaging container (1), wherein said front plane (5) is not parallel with said open surface of said container part (2). Packaging container (1) as claimed in claim 1, characterized in that both of said side planes (7, 8) form angles of larger than 90° with said front plane (5) of the packaging container (1). Packaging container (1) as claimed in claims 1 or 2, characterized in that said container part (2) and/or the closure part (3) are provided with rigidifying beads (14) at least on one of the walls comprising the front plane (5) as well as the two side planes (7, 8) of said container part (2) and/or a rear plane (11) of said closure part (3). Packaging container (1) as claimed in one of the preceding claims, characterized in that the closure part (3) is provided with a flange (12) and a depression (13) which is localized inside the flange (12) and which surrounds the closure part (3). Packaging container (1) as claimed in claim 4, characterized in that the flange (12) is angled in such a manner that it makes an angle of < 180° with the plane of the closure part (3). Packaging container (1) as claimed in one of the preceding claims, characterized in that the container part (2) is stackable and readily withdrawable from a stack of such prefabricated container parts (2). Packaging container (1) as claimed in one of the preceding claims, characterized in that the bottom wall of said container part (2) forming the front plane (5) is curved. Packaging container as claimed in claim 7, characterized in that the two side planes (7, 8) besides said front plane (5) are provided with concave depressions (15). Packaging container (1) as claimed in one of the preceding claims, characterized in that the opening arrangement (10) displays a covering panel which is fixedly sealed over a hole (9) in the side wall of said container part (2) forming the top plane (4). Packaging container (1) as claimed in one of claims 1-8, characterized in that the opening arrangement (10) consists of a prefabricated pouring spout whose mouth displays a closure device of the screw cap type or a push-on lid; and that said pouring spout is, by means of a flange disposed around the pouring spout, sealed to the hole (9) of the top plane (4) along the inside or outside of the top plane (4). Packaging container (1) as claimed in one of the preceding claims, characterized in that said opening arrangement (10) is attached on the top plane (4). Unit of packaging container (1) as claimed in one of the preceding claims, characterized in that one closure part (3) is covering the open surfaces of a plurality of said container parts (2).

Inventors: ROSEN AKE, ROSEN, AKE, Rosén, Ake 
Applicants: TETRA LAVAL HOLDINGS & FINANCE, TETRA LAVAL HOLDINGS & FINANCE SA
Application year: 1993
Main classification: B65D6
IPC codes: B65D6, B65D90, B65D17