Process of producing a deep-drawn container

Processes are disclosed for forming containers having the complete outer surfaces decorated and the bottom surface reinforced as well. In one embodiment a banderole is placed in a deep-drawing mold and length of drawable foil having a bottom blank secured thereto is fed to the mold. In a second embodiment the bottom blank is placed in the mold, together with the banderole prior to the feeding of the drawable foil. Pleating of the peripheral edge of the bottom blank prevents covering of the suction openings in the deep-drawing mold.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates generally to a process for producing 
deep-drawn containers and, more particularly, to a process for producing 
deep-drawn containers in the form of cups, pans or the like, which are 
formed of two material components. 
2. Description of the Prior Art 
Deep-drawn containers made from deep-drawable plastic foils, especially in 
the form of cups for packaging food, such as yogurt, cottage cheese, and 
other milk products and also ready-to-serve dishes or the like, are 
generally known. It is also known, depending on the desired make-up of the 
packaging, for example according to DAS No. 2,065,713, to introduce prior 
to deep-drawing in the deep-drawing mold a banderole with legends and/or 
illustrative pictures and to seal them at the same time. After filling, 
such deep-drawn packagings are covered with a metal foil. 
The bottom area of the cups or containers is excluded from this operation 
in the prior art process so that this area which, as a rule, because of 
the special character of the deep-drawing operation, is formed especially 
thin, remains unreinforced and is not very stable. Since the bottom 
remains uncovered, an overhead display arrangement of the goods cannot be 
considered as there is no "all-around-decoration." 
Basic to the present invention is the problem of providing a process by way 
of which the outer surface of the container can be completely covered, 
i.e. especially the bottom area, it being an object of this invention to 
permit, by way of such a process, the production of deep-drawn containers 
having a circumferentially applied thin aluminum foil which otherwise is 
no longer deep-drawable. The process of the present invention, as well as 
the product made thereby, has been desired for some time because the prior 
art deep-drawn plastic packages do not comply with the requirements for an 
absolute tightness relative to flavor, water vapor, oxygen and light, 
thereby limiting the storage stability of food packed therein. Packages in 
line with these requirements, it is true, are known. However, they have 
been drawn from a relatively thick aluminum foil, thus involving a 
substantial mechanical expenditure and with the depth of such container 
being relatively shallow. 
The problem is solved according to the present invention by means of a 
process of the aforementioned type in that connected to the deep-drawable 
component, prior to the introduction thereof into the deep-drawing mold 
and at intervals corresponding to the feeding cycle, there is provided a 
bottom blank corresponding to the bottom shape of the container to be 
produced but of slightly larger dimensions. The bottom blanks may be made, 
for example, of a thin, non-deep-drawable aluminum foil and are secured to 
the deep-drawable component from the bottom by heat sealing. During 
introduction of the deep-drawable component into the deep-drawing mold the 
bottom blanks, with the adhesive still hot, are placed precisely in the 
center of the mold and the bottom blank during deep-drawing in the 
deep-drawing mold is held from the bottom, for example by means of a die. 
In this manner, first a "roundabout decoration" and also a reinforcement of 
the bottom area can be achieved, with the problem of covering the suction 
opening in the deep-drawing mold, which would arise if the bottom blank 
were simply placed into the mold being avoided and solved in a most simple 
manner. 
Conversely, this process permits, when using for the components to be 
cemented, i.e. a side wall banderole and a bottom blank, a thin aluminum 
foil, to produce deep-drawn containers complying with all tightness 
requirements, especially cups of a substantial depth, which hitherto, has 
not been possible. 
The problem of covering the suction opening can also be solved differently. 
In addition to the banderole a bottom blank, the edge of which prior to 
insertion is radially folded and bent upwardly, is inserted into the 
deep-drawing mold so that the bottom edge of the banderole is positioned 
between the upwardly bent edge and the mold wall. 
Through the radial folding venting openings are provided between the 
banderole and the inserted bottom blank through which the drawn off air 
can escape. This process variant provides the additional advantage that 
the upwardly bent and pre-folded edge better abuts to the bottom banderole 
rim and establishes a connection therewith. 
Concerning the covering of the upper gusset or flange of the container, the 
two modes of operation may be so carried out that the blank web and the 
bottom blanks are heat sealed to the deep-drawable component and are 
introduced along therewith into the deep-drawing mold. 
With respect to the product produced according to the process of this 
invention it should be noted that for protection the side wall banderole 
of the deep-drawn container covers the rim bent upwardly during 
deep-drawing of the bottom blank and which was heat sealed prior to 
deep-drawing and is heat sealed therewith. Furthermore, the side wall 
banderole of the deep-drawn container covers the rim bent dowardly during 
deep-drawing of the concentrial edge blank or ring-like member and is heat 
sealed therewith. 
The apparatus for carrying into effect the process and for the preparatory 
production of the deep-drawing foil, respectively, is most simple and can 
either be associated in a suitable manner to the deep-drawing machine or 
can be operated independently thereof. However, in the latter case, the 
component blanks must precisely correspond to the working and intake cycle 
of the deep-drawing machine to which the latter are applied. 
In principle, such an apparatus is a punch combined with means to 
cyclically sealing the blanks with heat sealing adhesive on or to the 
deep-drawing foil. 
The process of the invention, the container produced according thereto and 
an apparatus for carrying into effect the process will now be described 
with reference to the graphic illustration of examples of several 
embodiments.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to the drawings, numeral 1 refers to the deep-drawable 
component to be withdrawn from a stock roll, reference character 2 refers 
to a very simplified and schematic illustration of the deep-drawing mold 
for molding the containers, numeral 3 refers to the spaces at which the 
bottom blanks (for example of aluminum foil) corresponding to the bottom 
shape of the container are cemented to the component 1 to the bottom of 
the blank web 1', and reference character 5 refers to the mold center-line 
of the deep-drawing mold 2. 
The apparatus need not necessarily be arranged in the precise manner as 
illustrated. It can also be provided at the right-hand side beside the 
bottom transport element then shifted toward the left-hand side, quite 
apart from the fact that, as set forth above, the punching apparatus 14 
can also be operated independently of the deep-drawing apparatus, which is 
generally designated by the reference character 13, in which case the 
fully prepared foil web will be applied to the deep-drawing apparatus. 
As has been found, the foil during deep-drawing of the deep-drawable 
component 1 readily expands from the regions to which bottom blanks are 
cemented as the still hot adhesive permits such an expansion of the foil. 
During deep-drawing, also in a known manner, a banderole 8 for the side 
wall that is inserted into the deep-drawing mold 2 is sealed, with the 
upwardly bent rim 10 of the bottom blank 4 being covered by the lower rim 
of the banderole 8, as shown in FIGS. 5 and 6. According to FIG. 6 also 
the area below the less critical container edge 6 may be covered by a 
corresponding ring-shaped blank 7 which is cemented onto the blank web 1' 
in the form of a corresponding blank concentrically to the blank 4. The 
rim 11 of the ring-shaped blank 7, which is bent downwardly during 
deep-drawing, is then covered by the banderole 8. After filling of the 
containers 9 according to FIGS. 5 and 6, the containers 9 may then be 
covered in a known manner with an aluminum foil (not shown). 
The components to be applied to the container surfaces, i.e. the banderole 
8, are preferably provided with a slight surface stamping or irregularity 
in a well-known manner so that air that may be entrapped during 
deep-drawing may be better removed. If the blanks 4 and 7 and the 
banderole 8 are made of an aluminum foil, the resultant containers 9 are 
tight in all respects so that for the first time deep-drawn containers of 
an extremely thin aluminum foil (approximately 0.03 mm thick), supported 
by a plastic base container, are available. 
To meet the eventuality that the bottom blanks 4 are slightly displaced 
during deep-drawing, which might occur, the deep-drawing mold, which may 
be of the type shown in U.S. Pat. No. 3,533,135, may be so formed that in 
the bottom part, such as is shown in FIG. 7, a ram 18 that is movable up 
and down is provided in an upper plate 19 for fixing the blanks 4 with the 
ram 18 being pushed downwardly by a pre-drawing die 20 during 
deep-drawing. 
As previously mentioned, the process of this invention may also be so 
carried into effect that the bottom blank is not inserted together with 
the deep-drawable component 1 into the deep-drawing mold 2 but is rather 
inserted beforehand with suitable elements. In order not to block the 
suction openings 21 of the deep-drawing mold 2, a bottom blank 4', such as 
shown in FIGS. 8 and 9, is provided with radial small pleatings at 16 at 
the edge 15 thereof. The pleatings 16 may be formed by bending the 
circumferential edge 15 upwardly. These pleatings 16 provide adequate air 
passage means so that the reduced pressure caused by the suction openings 
21 can also be effective within the banderole 8 and the bottom blank 4'. 
An apparatus applicable to both processes, by way of which a punched foil 
web 17' is introduced as a whole along with the deep-drawable component 1 
into the deep-drawing mold 2, is illustrated in FIG. 10. In the FIG. 10 
embodiment bottom blanks 4 are introduced along with the deep-drawable 
component 1. The punching means 14' punches the bottom blanks 4 and 
presses them, from the bottom, against the component 1. The remaining 
punched foil 17' is then fed, by means of foil tape supplying elements 19, 
to the component 1 in such a manner that the punched openings are disposed 
concentrically to the blanks 4. 
In case the bottom blanks 4' pleated at 16 are directly placed into the 
deep-drawing mold 2, which would then not require foil tape supplying 
elements 19, the punching means 14' would be eliminated at the indicated 
point. The punched remaining foil 17' will, of course, have to be 
introduced in the working cycle of the deep-drawing mold relative to the 
punching holes thereof.