Packaging container and material for manufacture of the same

In a packaging container of parallelepiped type, with material for manufacture of the same, there is, limited by means of fold lines, a fold-out corner flap (4) which contains a pouring opening (7) and serves as a pouring lip when pouring out contents in liquid form from the packaging container. In order to ensure that air can flow into the packaging container in conjunction with the pouring out of the contents the upper end wall (1) of the packaging container is provided with weakening lines (8), which diverge from the pouring opening and weaken the material to such an extent that the area at the rear end of the pouring opening stands out in a raised position obtained on the opening of the packaging container and facilitates the inflow of air.

FIELD OF THE INVENTION 
The present invention concerns a packaging container and more particularly, 
a packaging container of the type which is manufactured from a pliable 
material provided with a fold line and an upper end wall with two front 
corners, between which a fold-out corner flap is situated, with an 
openable part extending over both the corner flap and an adjacent part of 
the end wall. The invention also concerns a material for the manufacture 
of a packaging container of this type, comprising a bearing layer and a 
watertight thermoplastic layer attached to the bearing layer. 
BACKGROUND OF THE INVENTION 
Consumer packagings for liquid contents such as milk, juice or the like 
occur in a number of different versions. One of the better known, 
generally occurring packaging container types is manufactured from a 
flexible, pliable packaging material which contains layers of paper and 
thermoplastic and is fed to a packaging machine in linear form. After 
shaping the line packaging material into a a tubular form, the material is 
cross-sealed at regular intervals, whereby mainly pillow-shaped packaging 
containers provided with projecting sealing tabs are formed. The 
pillow-shaped packaging containers are converted to a mainly 
parallelepiped shape by the projecting sealing tabs being folded down and 
the mainly triangular, double-wall corner flaps occurring in the shaping 
being folded inwards and sealed to the outside of the packaging container. 
A packaging container of this type is thereby given an upper end wall 
which is mainly rectangular and has a fold-out corner flap at each short 
end. One corner flap is, like the adjacent part of the upper end wall, 
provided with a weakening and tear indicator line which makes it possible 
to tear off a part of the corner of the packaging container and thereby 
obtain a suitable pouring opening whose form and extent can vary as a 
result of the adaptation to the type of product for which the packaging 
container is intended. 
When the packaging container is to be opened, the corner flap provided with 
the opening device is freed from its seal against the side wall of the 
packaging container and is folded upwards and flattened from the sides, so 
that the consumer can tear off the part intended for this purpose and, 
provide a pouring opening. In order to ensure at the pouring thereby out 
of the contents through the pouring opening that a corresponding volume of 
air can simultaneously flow into the packaging container, the tear 
indication is usually shaped with a longish rear end, which mainly runs 
onward to the central part of the upper end wall. If the consumer does not 
open the packaging container completely, i.e. stops the tearing of the 
openable part before the material has broken as far as the aforesaid 
central part of the end wall, a surge problem arises in the pouring out of 
the contents, since the air is completely or partly prevented from 
penetrating into the packaging container. The same problem can also arise 
with certain product types of more viscous consistency. 
In order to eliminate the above problem it has been proposed that the 
packaging container should be provided at the rear end of the upper end 
wall with a separate air hole, which is opened in connection with the 
opening of the packaging's pouring opening. It is, however, difficult to 
provide any form of automatic opening of this air hole, which makes two 
separate opening maneuver necessary before the pouring out of the 
contents. This has in practice proved difficult to put into effect, and 
the problem of poor air intake and therewith the ensuing surge problem 
therefore remains to a certain extent. 
OBJECTS AND SUMMARY OF THE PRESENT INVENTION 
There is thus a general desire to provide a packaging container of the 
above type in which the opening procedure automatically leads to a pouring 
opening of such a shape that the contents can without any problem flow out 
at the same time as the lost volume of contents in the packaging is 
replaced with air flowing in from outside. 
An aim of the present invention is to provide a packaging container with a 
pouring opening which has such a shape and size that air can flow in 
unhindered into the packaging container as soon as one has begun the 
pouring out of the contents. 
A further aim of the present invention is to provide a packaging container 
with a shape that ensures, upon opening, that the pouring opening formed 
enables outflow of the contents without any surge problem, even if the 
packaging container is fully filled, i.e. completely filled with contents 
and lacking what is called head space. 
A further aim of the present invention is to provide a packaging container 
of the above type, which has a shape and design which largely accords with 
already known parallelepipedic types of packaging container and which can 
hence without difficulty be manufactured in the same type of packaging 
machine. 
These and other aims have according to the invention been achieved through 
the fact that a packaging container of the initially mentioned type has 
been given the characteristic that the upper end wall has two weakening 
lines, diverging in relation to each other, extending from the rear end of 
the openable part. 
An aim of the present invention is also to provide a material for the 
manufacture of a packaging container of the type initially mentioned, with 
this material being of such a design that it can be shaped without 
hindrance into packaging containers in conventional packaging machines 
without these needing to be modified or altered in any decisive manner. 
A further aim of the present invention is to provide a material for the 
manufacture of the above packaging container, with this material 
resulting, through only a simple modification in relation to the known 
materials for parallepipedic packaging containers, in a packaging 
container with considerably improved pouring properties. 
The above and other aims have been achieved according to the invention 
through the fact that a material of the type mentioned in the introduction 
is designed such that the surface of the material corresponding to the 
upper end wall comprises a number of lines weakening the material, which 
are arranged at an angle to each other so as together to delimit an area 
which, when the material is shaped into a packaging container, is arranged 
so as to stand out in a raised position obtained on the opening of the 
container. 
Through providing the material in the upper end wall of the packaging 
container with two suitably placed fold lines an automatic folding of the 
upper end wall is obtained in conjunction with the corner flap being 
raised and flattened from the side, which happens in the normal opening 
maneuver. The folding along the aforementioned weakening lines results in 
the area of the end wall that is situated at the rear end of the pouring 
opening being raised to a higher level than the original level of the end 
wall and standing out in this position, which, when the packaging 
container is tipped up to pour out the contents through the pouring 
opening, results in the rear end of the pouring opening getting into a 
somewhat higher position than with conventional packaging containers, so 
that the inflow of air to replace the volume of contents poured out is 
considerably facilitated. 
BRIEF DESCRIPTION OF THE DRAWING FIGURES 
A preferred embodiment of the packaging container and the material for 
manufacture of the same according to the invention will now be described 
with particular reference to the enclosed schematic drawings, which only 
show those details indispensable for the understanding of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Generally speaking, the packaging container according to the invention 
shown in FIG. 1 is of the well known type which is manufactured from a 
flexible packaging laminate containing a central bearing layer of fibrous 
material, for example paper, which is lined on both sides with watertight 
layers of thermoplastic material, for example polythene. The packaging 
laminate includes a pattern of fold lines, which facilitates the shaping 
of the originally linearformed packaging laminate to the finished, mainly 
parallepipedic packaging container. 
The shaping of the linear packaging laminate into individual, 
parallelepipedic packaging containers is done through the linear laminate 
being successively shaped into a tubular form so that both its 
longitudinal edges overlap each other and can be given a watertight seal 
with the aid of heat and the thermoplastic layer present on the outside of 
the laminate. As soon as a watertight longitudinal joint has been formed 
the tube is filled with contents of the desired type, e.g. milk, juice or 
the like, after which the tube is cross-sealed at regular intervals so 
that a connected strip of mainly pillow-shaped, filled packaging 
containers results. With the aid of transverse cuts in the sealing 
surfaces the individual packaging containers are separated and subjected 
to a final shape processing. In the processing to the desired 
parallelepiped shape four triangular double-wall corner flaps result, 
which are pressed flat and folded to lie against the respective parts of 
the outside of the packaging container and are maintained in this position 
through heat sealing. At the same time the sealing tabs occurring in the 
cross sealing of the upper and lower ends of the packaging container are 
folded to lie against the outside of the packaging container and through 
this a mainly parallelepipedic shape occurs, which is maintained until the 
packaging container is opened. 
As can be seen in particular from FIGS. 1, 2 and 3 the packaging container 
according to the invention formed in the above manner is given a 
parallelepiped shape with an upper end wall 1, four side walls 2 and a 
lower end wall, not shown. In the embodiment shown the upper end wall 1 is 
mainly rectangular, and a sealing tab 3 which is laid flat and lies 
against the end wall extends mainly in the centre over the end wall 
between the two short sides of the end wall. On the aforementioned short 
sides two corner flaps 4 are situated linking with the two front and rear 
corners of the upper end wall 1, and the sealing tab 3 runs along over the 
corner flaps to terminate at the free corners of the respective corner 
flaps 4 facing away from the end wall. At one or the front end of the 
upper end wall 1 the sealing tab 3 is provided with an opening indication 
5 in the form of a line weakening the packaging material, e.g. a 
perforation, which extends along the underside of the sealing tab between 
the end of the tab and an area near the central part of the upper end wall 
1, where the perforation runs up against the free edge 6 of the sealing 
tab. The opening indication thus delimits an openable part 3' of the 
sealing tab 3, with this part extending both over the corner flap 4 and 
the adjacent part of the end wall 1. When the packaging container is to be 
opened to enable the pouring out of the contents the corner flap 4 
provided with the opening indication is first freed from the outside of 
the packaging container, after which it is folded upwards and pressed 
together from the sides at the same time as the tear-off part 3' of the 
sealing tab 3 is torn along the opening indication 5. By this means a 
pouring opening 7 is formed, and the pouring out of the contents is 
facilitated by the fact that the present corner flap 4 in its folded-up 
state forms a pouring lip. 
When the packaging container is tipped forward after opening for the 
purpose of pouring out a part of the contents through the pouring opening 
7 it is desirable that the contents should leave the pouring opening in 
the form of an even, collected stream of liquid. In order to ensure this 
it is required that the volume of contents in the packaging container 
flowing out at the pouring out of the contents should be replaced by in 
flowing air, which is effected through the fact that air can flow in via 
the rear end of the pouring opening, i.e. the part facing the corner flap 
4 of the upper end wall 1 which is not folded upwards. In order to ensure 
this it is important that the consumer on opening the packaging container 
really uses the whole length of the opening indication 5, i.e. tears off 
the tear-off part so that the pouring opening 7 is given its maximum 
length. If this is not the case or if the contents present in the 
packaging have a high viscosity it can happen that a sufficient quantity 
of air does not flow into the packaging container during the first part of 
the opening process, particularly if the packaging container is completely 
filled. According to the invention, however, this disadvantage can be 
eliminated if one sees to it that the rear end of the pouring opening 7 is 
given a raised position in relation to other parts of the upper end wall 
of the packaging container, which gives a greater margin and ensures that 
the necessary amount of air flows into the packaging even in difficult 
pouring conditions. In order to achieve the desired raising of the rear 
end of the pouring opening 7 the upper end wall of the packaging container 
according to the invention is provided with two weakening lines 9, which 
extend from the rear end of the openable part and diverge in relation to 
each other. The lines 9 diverge more specifically in a direction towards 
the rear part of the upper end wall 1, which is preferably provided with 
two other weakening lines 8, which together with the two first weakening 
lines 9 enclose a central, mainly rhomboid area of the end wall. Through 
providing the end wall 1 with both the front and rear weakening lines 8, 9 
the end wall acquires a tendency to fold at these lines in conjunction 
with the folding up and pressing together of the front corner tab 4 when 
the packaging container is to be opened. The rhomboid area situated 
between the fold lines 8,9 by this means forms a sloping plane, which 
connects at its rear end with the original level of the upper end wall 1 
and at its front end is 3 to 6 mm above the said level, which makes it 
possible for the rear end of the pouring opening 7 to be raised a 
corresponding distance in relation to the surface of the liquid at the 
pouring out of the contents from the packaging. This gain in level ensures 
that air can flow into the packaging container even when the consumer has 
not opened it completely or the current product, owing to its viscosity, 
has an increased tendency to surge. 
With the aid of especially the two front weakening lines 9 the upper end 
wall 1 of the packaging container is given a concentrated weakening, which 
sees to it that the part of the end wall stands out in the upper position 
it naturally assumes in conjunction with the folding upwards of the corner 
flap 4 and the opening process. This tendency is reinforced and made 
permanent when the lines 9 extend symmetrically on both sides of the 
sealing tab 3, and it has proved to be optimum if the first weakening 
lines 9 extend mainly in the direction of the middle of the upper end wall 
1 with side edges parallel to the sealing tab 3. According to a preferred 
embodiment the angle between the first weakening lines 9 is approximately 
120.degree., but the weakening lines 9 have proved to give a certain 
effect even with a different line, and an improvement has been observed 
when the fold lines have a mutual angle of between 60.degree. and 
160.degree.. 
The two rear weakening lines 8 are likewise arranged mainly symmetrically 
in relation to the sealing tab 3, and the angle between them is preferably 
in the main 60.degree.. In order to achieve the desired effect it has 
proved suitable if the angle between the rear weakening lines is at the 
maximum 90.degree.. 
The weakening lines 8, 9 can be made as conventional fold lines, where the 
packaging material is pressed together in linear form in order to obtain 
the desired weakening, but it is also possible to form the weakening lines 
in another manner, e.g. through linear perforation of the bearing layer. 
If the weakening lines 9 can in this way be made sufficiently strong, the 
two rear weakening lines can if desired be omitted since the front lines 9 
weaken the material to a sufficient degree to ensure a maintained raised 
position of the end wall 1 at the rear end of the pouring opening 7. 
A material for manufacture of a packaging container according to the 
invention is shown in FIG. 4. The material consists of a terminated 
material containing e.g. a bearing layer of paper, which is lined on both 
sides with homogeneous layers of thermoplastic material, e.g. polythene. 
The material shown can form part of a packaging material line and contains 
a pattern of fold lines 10, which divides the material into rows of a 
number of wall panels, e.g. side wall panels 11, bottom panels 12 and 
upper end wall panels 13. The pattern of fold lines also comprises fold 
lines for the formation of the corner flaps 4 but is mainly conventional 
and should therefore not need to be described in greater detail in this 
connection. By means of a dotted line the opening indication 5 is also 
indicated, which has the form of a perforation which extends in the narrow 
area at one side of the packaging container material which is to form the 
upper sealing tab 3 of the packaging container. With thick, solid lines 
the two front weakening lines 9 are also indicated as well as the two rear 
weakening lines 8 according to the invention, which are placed on the end 
wall panels 13 delimited by means of the fold lines 10 which will together 
form the upper end wall 1 in the finished packaging container. The 
weakening lines 9 extend mainly at an angle between on the one hand a fold 
line 14, which delimits the field which forms the sealing tab 3 in the 
finished packaging, and a fold line 15 parallel to fold line 14, which in 
the finished packaging delimits the upper end wall 1 from the adjacent 
side walls 2. The angle of the weakening lines 8, 9 to the two fold lines 
14, 15 varies depending on the size and shape of the current packaging 
container, but remains within those limits which are determined by the 
previously mentioned angle values. 
While this invention has been illustrated and described in accordance with 
a preferred embodiment, it is recognized that variations and changes may 
be made and equivalents employed herein without departing from the 
invention as set forth in the claims.