Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to an opening means for
packaging containers which are made of flexible material, and the
opening means has at least one pouring opening which is provided
in the upper wall of the container and which is disposed adjacent
an edge line of the container and is covered with a layer of
material which can be broken open.
Liquid foods, i.e. dairy products such as milk, cream,
fruit juices and the like are nowadays usually packaged in con-
tainers which are intended to be used once. The containers are
made from laminated web or shee~ material, which usuall~ comprises
a main layer of paper or foam and, on both sides thereof, a
homogenous layer of thermoplastic material The containers are
formed by folding the sheet or web material, and heating and
pressing together the marginal regions of the folded packaging
web or sheet material results in liquid-tight and relatively
stable containers.
In order to enable the contents of the container to be
discharged therefrom, the containers are provided with a form of
opening means. In its simplest Eorm, the opening means can
comprise a cut-off corner of the container, but usually the
opening means used is in the form of complicated opening means
which may be opened without the use of tools and which can in
addition often be re-closed.
~ known packaging container of primarily parallelepiped
shape, which is made from a packaging material comprising layers
of paper and thermoplastic material, has an opening means of -the
klnd mentioned above, which is disposed on the upper surface of
the contalner. The opening means comprises a pouring opening
which is provided in the upper surEace of the container and which,
to facilitate discharginy the contents from the container, is
disposed at one of the edge lines which delimit the upper wall
from the side surfaces of the container. In order further to
facilitate pouring the contents out of the container, the pouring
opening is of an elongate or oval configuration and is so oriented
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~- that the long axis of the pouring opening extends predominantly
`normal to the above-mentioned edye line of the container.
This arrangement makes it possible for air to be sucked
into the container ~hile the contents thereof are being poured
from the container at the same time, the air ~hich is drawin into
the container replacing the part of the conten~s which has already
been poured out of the container and ensuring that the contents
are poured out of the container in a regular smooth flow. In
addition, the opening means has a cover strip of plastics material,
which is so disposed at the top of the container that it covers
both the pouring opening and also a region surrounding the
pouring opening. The cover s~rip is fluid-tightly sealed to the
top of the container in a region around the pouring opening. The
cover strip also has an end portion which is not sealed to the
containex and which is folded and extends upwardly substantially
from the top surface of the container, in order to make it easier
to break open the cover strip. As already mentioned, the pouring
opening is of such a shape that the contents of the container
can normalIy be poured out of the container in a regular and
fairly concentrated flow.
If the container is completely full however, and some
of the contents is to be poured out through the pouring opening,
it has been found that the angle of inclination of the container
is so small that the flow of liquid from the containPr has a
tendency to follow the outside of the container, sa that the flow
of liquid divides and part runs down the side wall of the
container. This occurs primaxily because the liquid being poured
from the container runs over the edge line which is formed when
producing the container by folding along a bending line, so tha~
-the edge line is slightly rounded and is not sufficiently well
defined that the flow of liquid from the container will
"come away" from the outside surface of the container. To
overcome this problem, it has been proposed that a more marked
pouring edge may
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~ provided by means of a separate strip of material which is joined
to the top of the container in such a position that it extends
substantially over the oriyinal edge line of the container. This
arrangement provides a well-defined flow of liquid when it is poured
from the container, even when the li~uid is being poured out of a
container which is almost completely full. However, difficulties
arise in connection with processing the separate pouring edge member
in the automatic packaging machines in which the packaging container
is produced and filled, and in addition the pouring edge member can
easily suffer damage when the container is being transported.
It is the problem of the present invention, overcoming the
advantages of the above-described opening means, to provide an opening
means which can be easily and reliably produced and which operates
correctly.
In addition, the invention aims to provide an opening means
which can be easily produced in the packaging machines which are used
at present, without requiring increased technical or economic measures.
According to the invention, this problem is solved by an
opening means for a packaging container made of flexible material,
said opening means having at least one pouring opening disposed in
the top wall of said container adjacent an edge line of said container
and covered by a layer of material, said opening means having a
container side wall adjoining said edge line, which side wall has a
slot extending through the wall somewhat below said edge line and
sealed off from the interior of said container by a fluid tight
layer, wherein the portion of material between said edge line and
said slot is forwardly pivotal for the purposes of forming a pouring
edge member disposed in the same plane as said top wall of said
container and which projects from said edge line. By virtue of this
construction, the above-mentioned portion of material . . . . . .
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between the e~ge line and the slot, by virtue of the flexibility
of the material thereof, sprinys outwarclly towards a position in
which it is in the same plane as the top of the container, when
the removable layer of material (i.e. a so-called pull tab) is
removed. The abovementioned portion of material thereafter acts
as a pouring edge member.
A preferred embodiment of the opening means according
to the inventior~ also has the characterising features that the
fluid-tight layer comprises a cover layer in the form of a separate
strip which is sealed to the inside surface of the container
material, in a region extending around the slot.
A further preferred embodiment of the openlng means
according to the invention is further characterised in that the
cover layer which is provided on the inside of the container
material covers both the slot and the region around the slot, and
also the pouring opening, while the portion which lies in the
pouring opening is sealed to the inside of the tear-off layer of
material. By virtue of this arrangement, the cover layer which
is provided on the inside of the container material is also
broken through, when the tear-off strip or pull-tab is removed
from the top of the container.
The slot preferably extends parallel to the edge line,
and it has been found that a distance of from 1 to 5 mm between
the slot and the edge line results in a pouring edge member of
suitable size. In order to facititate the outward pivotal
movement of the pouring~edge member to the active position in
which it is disposed substantially in the same plane as the top
of the container, the slot may have end portions which connect
the ends of the slot to the edge line.
In order to facilitate the outward pivotal movement of
the pouring edge member when the tear-off strip is removed, the
tear-off strip may be joined to the outside of the pouring edge
member for example by a connection which can be broken relatively
easily. It is also possible for the outward pivotal movement
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of the pouring edge member to be facilitated by both the
pouring edye member and the top wall of the container being
connected to a layer of material which after outward pivotal
movement endeavours to return to the planar position, for e~ample
a portion of suitable resilient plastics material.
The tear-off layer of material advan~ageously covers
both the pouring edge member and the pouring opening, and the
pouring edge member is advantageously held in a downwardly bent
position when the container is unopened, by securing the layer
of material to the outside of the container; holding the pouring
edge member in the downwardly bent position ensures that the
pouring edge member does not suffer damage when the container
is being transported.
The opening means according to the invention is described
in greater detail hereinafter with reference to the accompanying
diagrammatic drawings in which:
Figure 1 shows a packaging container of known kind,
with an opening means according to the invention, and
Figure 2 shows a view on an enlarged scale and in
partial cross-section of a packaging container with an opening
means according to the invention.
The packaging container shown in Figure 1 is of known
parallelepiped shape and is made of laminate material which has
a central main layer of paper which is coated on both sides with
homogenous thermoplastic material. The material forming the
packaging container can also comprise layers of other material,
for example a material with good gas barrier properties~ such
as aluminium foil and the like.
The illustrated container is produced by a process in
which a we~ of the material for forming the container is bent by a
packaging machine to form a tube configuration, with a primarily
vertically downward movement, whereupon the longitudinal edges
are joined together. The tube is filled with the desired contents
and then is divided into individual packaging members by
successively pres~lng the tube flat and then sealing it by
transverse seals along narrow sealiny regions. Finally, the
container is subjected to a shaping operation which imparts to
the container the desired para]lelepiped shape comprising a top
face 1, and opposite bottom face (not shown) and four side faces
of which only side faces 2 and 3 are shown in Figure 1. The
drawing also shows on the side face 2, one of the sealing seams
~ which is produced when manufacturing the container, and one
of the four corner portions 5 which for reasons of geometry are
produced when the container is being shaped. The corner portion
5 shown in the drawing is bent downwardly and is connected to the
actual side wall 2.
The opening means according to the invention is shown
in Figure 1 in an open condition, from which it will be clearly
seen that the opening means comprises a substantially oval
discharge means 6, a layer of material which can be torn off, or
a cover strip, indicated at 7, and a pouring edge member 8 which
can be pivoted outwardly from a position in which it is in the
same plane as the side wall 2 (or more precisely the corner
portion S). In the following more detailed description of the
opening means according to the invention, reference is made
primarily to Figure 2 which shows the opening means on a larger
scale and partially in cross-section, in the closed condition.
Figure 2 shows a part of the container of Figure 1,
more precisely a part of the top face 1 of the container, a part
of one side face 2 of the container, and an edge line 9 which is
disposed between the two faces 1 and 2. Disposed in the top face
1 of the container, as already mentioned, is a pouring opening
6 whose forward end is ad-Jacent the edge line 9 (usually at a
distance of from 5 to lOmm). The pouring opening 6 is of an
oval or teardrop-like configuration and is so arranged that its
longer axis of symmetry is normal to the edge line 9. This
arrangement substantially facilitates pouring the contents of
the container through the pouring opening, as, when the
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container is held a-t an angle to pour out its contents, the
contents can flow out through the part of the pouring opening
6 which is closest to the edge line 9, while at the same time
air can flow into the container through the opposite part of the
pouring opening, whereby the quantity of liquid poured out of the
container is being continuously replaced with the corresponding
amount of air, thus ensuring that a vacuum is not formed in the
container and thus avoiding the pouring problems which result
therefrom, in the form of so-called gurgling, as the liquid
contents is poured out.
When the opening means is in the Figure 2 unopened
position, the pouring opening 6 is covered with a layer 7 which
can be bro~en open. This layer 7 is in the form of a cover strip
which is made from fle~ible plastics material, and which is
usually also referred to as a pull-tab. The pull-tab is so
disposed on the top face 1 of the container, that it covers the
pouring opening 6, and extends over the edge line ~ and down
along the side face 2 of the container, where it terminates at
a small distance below the edge line 9 in a free end portion 11.
The end portion 11 is bent outwardly somewhat from the side
face 2 of the container and serves as a pulling tab when the
container is to be opened. The cover strip 7 is joined to ~he
outside of the container, partly at the top face 1 of the
container, in region 12 which is in front of the pouring opening
(i.e. to the right in the drawing), and partly in one or more
regions 13 at the side face 2 of the container; the one or more
regions 13 are disposed directly at a fold line 1~ which delimits
the above~mentioned pulling tab 11 from the remainder of the cover
strip 7. The above-mentioned sealing regions 12 and 13 are
formed b~v heating and pressing together the thermoplastic cover
strip and the thermoplastic outer layer of the material forming
the container. The sealing region 13 is of very restricted area
and only serves to hold the part of the cover strip 7, which
lies against the side face 2, in the position shown in
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Figure 2, before the container is to be opened. The sealing
region 12 at the opposite end of the cover strip is of consi~erably
larger area and is provided not only to hold the cover strip 7
against the top face 1 of the container when the container is
still unopened, ~ut also serves to connect the cover strip 7
to the container after the container has been opened, that is to
say, when the two sealing regions 13 have been broken by pulling
on the pulling tab 7 and the cover strip 7 has been bent over to
the open position, as shown in Figure 1. By virtue of this
arrangement the cover strip 7 remains on the container even
after the container has been opened, and can be used for re-
closing the pouring opening 6.
As will ~e seen from the foregoing description, neither
the sealing region 12 nor the sealing region 13 have a fluid-
tight sealing function. Instead, the air-tight and fluid-tight
closure of the pouring opening 6 is provided by a further layer
15 of material, which is disposed in the container and which is
largely identical to the cover strip 7 in respect of shape a~d
length. The layer 15 is made of thermoplastic material and is
2Q sealed to the inward face of the container inter alia in a region
16 ~hich is disposed around the pouring opening 6. In order
to provide a satisfactory pouring opening when the cover strip
7 is removed from the top face of the container, the cover
strip 7 and the layer I5 are joined together in a sealing region
17 which is in the pouring opening 6. By virtue of this
arrangement, when the cover strip 7 is removed, the portion of
the layer 15 which is in the pouring opening 6 tears primarily
along the periphery of the pouring opening 6, and the cover
strip 7 is torn away therewith in such a way that -the pouring
opening 6 is opened and the contents of the container can be
discharged therefrom.
In order to ensure that, when the container is being
emptied, the contents of the container do not flow along the
side face 2 after they have passed along the flow path between
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the pouring opening 6 and the edge line 9 on the upper face
1 of the container, the openiny means according to the invention
has an extensible pouring edge member 8. The pouring edge member
8 is formed by a slot 18 which extends through -the material of
the container and which is formed in the side face 2. The slot
18 extends substantially parallel to and at a spacing of from
1 to 5 mm relative to the edge line 9, at an inclined angle in
an upward direction. soth the slot 18 and the end portions 19
thereof extend entirely through the material forming the container.
To prevent the contents of the container from leaking through
the slot, the above-mentioned layer 15 is sealed to the inside
surface of the material of the container, not only at the region
16 which surrounds the pouring opening 6 but also at a further
sealing region 20 which in part coincides with the region 16
and extends around the slot 18 and seals off from the interior
of the container both the slot 18 and its end portions 19. With
this arrangement, the layer 15 forms a pocket which lies behind
the pouring edge member and in which the layer 15 and the
pouring edge member 8 are not joined together. As this pocket is
fluid-tight separated from the interior of the container by the
region 20 around the slot 18, the contents of the conatiner do
not leak out through the slot 18 when the pouring edge member
is in the inoperative position shown in Figure 2, or when the
pourlng edge member 8 is in the open position shown in Figure 1.
As the originally flat material for forming the container enjoys
a certain degree of inherent elasticity, when the cover strip 7
is removed the pouring edge member 8 automatically folds out-
wardly and forms a projecting edge. Depending on the type of
material, when the pouring edge member 8 is liberated by removal
of the cover strip 7, the pouring edge member 8 will move into an
operative or active position in which it is more or less disposed
in the same plane as the top face 1 of the container. If ~he
container and thus also the pouring edge member are made of a
material which is a pure plasticsmaterial, comprising a central
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layer of polystyrene foam covered on both sides with layers of
homogenous thermoplastic material, then the elasticity of this
material is sufficient to move -the pouring edge member 8 fully
into its operative position so that it is virtually completely
in the same plane as the top face 1 of the container.
With some kinds of container material, which have a
poor degree of elasticity, it may be necessary to provide for
means which facilitate the outward pivotal movement of the pouring
edge member, in conjunction with the operation of opening the
opening means. This can be achieved for example by the cover
strip 7 also being joined to the outside surface of the pouring
edge member 8 by means of a releasable sealing connection, or
alternatively by providing a layer of material of the type
(for example resilient plastics material) which after having been
bent attempts to return to a planar position, such layer of
material being so arrange as to extend over the edye line 9 and
being joined both to the pouring edge member 8 and to the top
wall 1 of ~he container.
In a known kind of opening means, the cover strip 7 is
sealingly joined to the top face of the container, in a region
which extends around the pouring opening. In this way the outer
cover strip 7 also performs a sealing function, and a layer of
material within the container, to give a sealing action at this
position, is not required.` If a pouring edge member according
to the invention is to be combined with such a form of closure
for closing the pouring opening, it will be understood that it
is desirable for the layer 15 to be only of sufficient siæe to
cover the slot 18 and its two end portions 19 and to be sealed
to the inside surface of the container in a region around the
pouring edge member 8. The part of the layer 15 which seals the
pouring opening 6 from the interior of the container can thus be
omitted.
Another alternative embodiment of the opening means is
also conceivable, and is particularly advantageous in the above-
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described kind of opening means in which the cover strip 7 isfluid-tightly sealed to the top face of the container. This
further embodiment of the packaging means according to -the inven-
tion also presupposes that the container which is provided with
the opening means comprises a laminate material which has a
fluid-tight layer towards the interior of the container, the
fluid-tight layer being sufficiently strong and tough to be
able to withstand the loadings applied thereto during the
operations of manufacturing, filling and handling the container,
withoutstraining the other layer forming the material forming
the container. In this embodiment, the inner plastics layer of
the container ls used as a sealing layer in front of the pouring
edge memberand the slots which form the pouring edge member,
whereby it is possible to omit the above-described fluid-tight
layer which is in the form a separate strip of material. With
this alternative embodiment, the other layers forming the material
of the container must be removed from the inner plastics layer
in the region of the pouring edge member 8, so that the pouring
edge member 8 can be bent outwardly witho~ hinderance, when the
cover strip is removed from the container. This adhesion-free
region which is required under the pouring edge member 8, and
similarly for example the pouring opening and the slots forming
the pouring edge member, must be formed when manufacturing the
laminate material for forming the con-tainer; this may easily
be effected by using one of a number of methods of preventing
the component materials from being laminated together in certain
regions thereof, eor example by applying an adhesion-preventing
agent in the above-mentioned regions, by providing a recess
corresponding to that region in one of the rolls with which the
layers for forming the container material are pressed together,
whereby the layers are not pressed together, or by cooling the
plastics layer to such a low temperature that there is no
adhesive action.
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In order further -to facilitate producing the above-
mentioned adhesion-free region, this may be in the form of a
continuous region which extends continuously along the web of
material, thus avoiding the necessity for ensuring that the
positions of the adhesion-free regions are adapted to the positions
of the pouring edge members which have already been stamped out.
It has been found that the presence of a single continuous
adhesion-free region is of no disadvantage as regards th~
finished container, as the resulting tubular space between the
coating layer and the main layer of the container material is
sealed off from the interior of the container, in the repeated
operation of transverse sealing of the tubular web of container-
forming material. The continuous adhesion-free region is advan-
tageously formed by an operation in which the plastics material,
during the coating step, is continuously subjected to a blast
of compressed air and cooled.
The opening méans according to the invention is produced
by forming the pouring opening 6 and slots 18 and 19 in the cont-
ainer material while it is still in the form of a web, at equal
intervals whose length corresponds to the length of material for
forming each container. The web of material is already provided
with a preliminary trace for the bend line, to facilitate the last
operation of making the container into its parallelepiped
shape, and the operation o~ punching out the pouring opening 6 ~ -
and the slots 18 and 19 can therefore be performed with a high
degree of precision, for example in relation to the bending line
which marks the furture edge line 9 to be formed. After the
punching operation, the web of container material receives
. the layer 15 at the appropriate points thereon; after the
application operation, the layer 15 is heated to a suitable
temperature and sealed to the web of container material in the
regions 16 and 20 disposed around the slots 18 and 19 and the
pouring opening 6. In the subsquent operating stations, cover
strips 10 are fitted to the container material, the cover strips
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being applied from the oppsite side, heated, and sealed -to the
container material in ~lle regions 12 and 13. The m~terial which
is provided in this way with the opening means of the invention
is thereupon passed into a packaging machine of known type, in
which it is converted into individual filled containers.
In order further to promote the automatic outward
pivotal movement of the pouring edge member when the cover strip
7 is removed, it is advantageous for the fold line which defines
the edge line 9 to be interrupted in the region in which it joins
the pouring edge member, whereby the pouring edge member is
subjected to a higher force for returning it to a position in
which it is in the same plane as the ~op wall of the container.
It is also advantageous according to the invention for
connecting positions 22, which are for e~ample welded or adhesi~e
positions, to be provided between the tear-off layer 7 and the
pouring edge member 8, in the lower region of the pouring edge
member, that is to say, in the area defined by the slots 1~ and
19 and the fold~ ne 9. These connecting positions will provide
an additional ~orce for assisting the pouring edge member to move
into its upward extended position when the layer 7 or the cover
strip 7 is torn off, in addition to the resilient force already
inherent in the material forming the pouring edge member~ At
any event howe~er it is advantageous for bo-th the -top surface
1 of the container and also the pouring edge member 8 to be of a
materiaI which has a sufficient degree of inherent resiliency
for the pouring edge member to pivot upwardly into the plane of
the top wall 1.
The opening means is rendered partlcularly easy to
~: operate, and can be used for re~closing the container, by a
further preferred feature according to the invention, namely that
the layer 7 which is in the form of a tear-oEf cover strip is
coated with thermoplastic material and is non-releasably secured
to the top wall 1 of the container, at the end of the cover strip
7 which is remote from the powring edge member 8. In this case,
the user of the container pulls the cover strip 7 up, although
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the end of the cover strip 7 remote from the pouring edge
member 8 is secured to the body of the container at a sealed
seam (not shown in the drawings) which extends transversely
across the top wall 1 of the container. This seam may be
necessary for example in manufacturing -the container, that is
to say, in the operation of closing the tube for forming the
container, as is the case with the seam 4 in the Figure 1
embodiment. It will be understood that a sealed seam as mentioned
; above, which extends across the top wall 1 parallel to the edge
9, is made very firm so as to ensure that the cover strip 7
cannot be torn off beyond this limit. Consequently, after the
container has been opened in use thereof, the cover strip 7
reliably remains approximately in the position shown in Figure 1,
and is therefore available for re-closing the opening 6. If in
a preferred embodiment the cover strip 7 comprises a thin metal
foil, the gripping end portion thereof may be pressed under the
somewhat projecting pouring edge member 8 (see Figure 1), so
that the pouring opening 6 can be re-closed in a dust-proof
manner.
The opening means according to the invention provides
for the simple and uncomplicated formation of a satisfactory
pouring edge member which projects from the edge line of the
container after the container has been opened. In the in-
operative or inactive position, -the pouring edge member is well
protected and is highly unlikely to suffer damage in handling,
so that it operates well when the container is opened.
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