Note: Descriptions are shown in the official language in which they were submitted.
128S91~
PACKING CONTAINERS AND BLANKS THEREFOR
The present invention relates to packing
containers, e.g. of the ridge roof type ~so-called
gable-top package). Packages of this kind are
05 typically manufactured from a plane, substantially
rectangular blank of a cardboard material or a
comparably rigid but foldable material which is
provided with a suitable crease line pattern and is
formed to a tube, one end of which is given a bottom
10 closure of any chosen kind and the other end of which
is closed by means of so-called bellows folding with a
sealing fin arranged on top of it formed of the edge
zone of the packing container, that is to say a top
closure which below the sealing fin consisting of the
15 edge zone comprises four rectangular end panels, of
which two are preferably placed obliquely to each
other whilst each of the other two is divided into
three triangular panels and folded in under the
sealing fin to form so-called bellows folds, the
:: 20 sealing fin consisting, at least to the greater part,
n of four material layers which are joined to one
another by means of a sealing operation.
In packing containers of the aforementioned type
it has been a problem to make them tight and at the
: : ~ 25 same time openable. It has been found impossible up
to now to fulfil both these requirements in a
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satisfactory manner and it has been more or less
unavoidable to sacrifice the tightness of the
container in favour of making it easily openable.
There is a need therefore, to eliminate the said
05 problem of the known packing containers and make
available a packing container which is both easily
openable and at the same time satisfactorily tight.
The present invention provides a packing
container having wall portions which are folded and
sealed together to form an end closure for the
container comprising a fin, wherein the fin is
provided with a line of weakening running
longitudinally therealong and the wall portions
forming the fin are sealed to one another
substantially more strongly above the line of
weakening than immediately below the line of
weakening.
The invention includes a blank for folding and
sealing to form a container, which blank has at one
end a transverse running strip for folding and sealing
to form a fin, within which strip is provided a line
of weakness running along the strip, wherein a seal
nhibiting composition is provided on said strip on
; the container interior side of the line of weakness.
25The invention further includes a web of such
blanks.
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Preferably, in the sealing fin above one of the said
bellows folds, a tearing indication weakening the materials lay-
ers is provided along a line between, and preferably parallel
with, the top line and the foot of the seallng fin, and the seal
between the material layers below this tearing indication is made
substantially weaker or almost negligible compared with the seal
between the material layers above the tearing indication.
In accordance with one aspect thereof the present
invention provides in a packing container of the type which is
manufactured from a plane, substantially rectangular blank of a
substantially rigid but foldable and tearable material, said
b~ank including a crease line pattern, an edge zone along one
side thereof, and four rectangular end panels ad~acent said edge
zone, said blank being formed into a tube having two ends, a
first of said two ends having a bottom closure and a second of
said two ends being closed by a bellow folding including a seal-
ing fin, said sealing fin being formed from said edge zone, two
of said four rectangular ends panels being placed obliquely to
each other and another two of said panels each bsing divided into
three triangular panels and folded inwardly of said tube to form
said bellow folding, four material layers of said blank being
~oined to one another in said sealing fin, the improvement com-
prising said sealing fin including a top line ad~acent said one
side thereof and a footline ad~acent said bellow folding and a
tearing indication is provided in said sealing fin along a line
between and parallel to said top line and said footline to weaken
the material layers along said tearing indication, a first seal
being formed between the material layers between said tearing
indication and said footline and a second seal being formed
between the material layers between said tearing indication and
said top line, said first seal lmmediately ad~acent the tearing
indication being substantially weaker than said second seal lmme-
diately ad~acent the tearing indication so that said tearing
indication defines a boundary line between strongly sealed mate-
rial layers and weakly sealed material layers. Desirably said
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firsl seal is made weaker than said second seal by coating said
first region with a seal-reducing agent.
In another aspect thereof the present invention pro-
vides a packing container having a substantlally rectangular
transverse cross-section and including wall portions which are
folded and sealed together to form an end closure for the CO4-
tainer lncluding a fin having an edge, a llne of weakening being
provided in said fin and extending longitudinally therealong,
said wall portlons lncluding flrst and second pairs of opposed
top sides, sald flrst palr of opposed top sldes belng brought
together and said second pair of opposed top sides belng folded
inwardly and caught between said first palr of opposed top sides
to form said fln, seallng means belng provlded for seallng sald
first and second pairs of opposed top sides together, and sealing
inhibiting means being provided for inhibiting sealing between
said first and second palrs of opposed top sides in a first
region thereof, said line of weakening defining a boundary line
between sald first region where sealing is inhibited and a second
region between the line of weakening and the edge of the fln
where sealing is provided. Desirably said wall portions include
first and second pairs of opposed rectangular panels, said first
pair of opposed panels being leaned obliquely against one another
and each panel of said second pair of opposed panels being
divided into three triangular panel sections and folded inwardly
between said first pair of opposing panels, said first and second
pairs of top sides being provided ad~acent said first and second
pairs of panels. Preferably the seal between all contactlng sur-
faces of the top sides is reduced below said line of weakening in
the fin. Suitably the sealing inhibiting means lncludes a coat-
ing on said wall portions which includes a seal reducing agent.
Preferably said line of weakness is a line of perforation extend-
ing through a part only of the container wall thickness, the
remaining thickness being liquid tight. Alternatively said line
of weakening consists of a perforation provided ln the fin in the
form of through-holes or slots covered by a liquid-tight plastics
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layer.
The present invention aga~n provides a container blank
comprising a transverse running strip extending along an edge of
sald blank, said running strlp including a crease llne permltting
the running strip to be foldable to form a fln; a line of weaken-
ing within said running strip whicA extends along said strip and
which defines a boundary line between first and second regions of
said running strip, said first region being defined at a side of
said boundary line opposite the edge of the blank; and a seal
inhibiting composition provided on said strip only in said first
region. Suitably said blank is divided by fold lines into panels
and further comprises four substantially rectangular side wall
forming panels, four substantially rectangular end closure form-
ing panels, two non-ad~acent ones of which are each sub-divided
into three triangular panel sections, and four substantially
rectangular strip forming panels. Desirably said line of weak-
ness runs through one whole strip forming panel and extends
appro~imately half way along two strip forming panels ad~acent
said one strip forming panel. Preferably the seal inhibiting
composltion occupies an area bounded by the line of weakness and
a border between the strip forming panels and the end closure
forming panels on a face of the blank adapted to be an interior
face of the formed container. Suitably the seal inhibiting com-
position is also present on a face of the blank adapted to be anexterior face of the formed container in a region contained
within said one whole strip forming panel bounded by the line of
weakness and the border between the strip formlng panel and the
ad~acent end closure forming panel. Suitably a surface of two of
said strip forming panels ad~acent said sub-divided end closure
forming panels is folded back on itself and sealed, and wherein
said seal inhibiting composition is provided on said surface to a
side of said line of weakening opposite the edge of said blank.
The invention will be described in more detail in the
following with reference to the attached drawings which, by way
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of example, show an embodiment of a packing container in accor-
dance with the same.
Flgure la shows the part of a plane rectangular blank
whlch is intended to form the top of a packing container:
Figure lb shows a raised but not yet closed packing
container manufactured from the blank shown in Figure la;
Figure lc shows the closed top of the packing con-
tainer;
Figure ld represents the packing container during an
opening stage; and
Figure le shows the container fully opened.
The packing container shown ln Figure lb is made from a
substantially rectangular blank of a cardboard.
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material or a comparable rigid, but foldable material
coated with plastics on both sides. The crease line
and tearing indication pattern is evident from Figure
la which thus shows the part of the blank which is
S intended to form the top part of the packing
container. After the blank has been provided with the
crease line pattern, as shown in Figure la, it is
formed into a tube (Figure lb) by sealing together its
two longitudinal edges in, for example, a so-called
overlap join. In Figure la the overlap lug required
for the formulation of the overlap join is designated
la. One end of the tube formed is given an optional
kind of bottom closure which, however, is of no vital
importance for the invention and is not-shown,
therefore, in greater detail.
The tubular part of the packing container
consists of four side walls 3 which are delimited by
side edge lines 4, the bottom edge lines 4 and upper
boundary lines 6. The upper end of the blank, and
hence of the tube, has been provided beside the crease
lines 6 with crease lines 7 running parallel with
these and further crease lines 8a, b and c which form
two letter Y turned upside down. As a result the
upper end of the packing container can be closed by
means of a so-called bellows folding with a sealing
fin 10 arranged above it, formed of the upper edge
~28S916
zone 9 of the packing container ~Figure lc), that is
to say a closure which below the sealing fin
consisting of the edge zone comprises four rectangular
end panels 11,11,12 and 12 of which two panels 11 are
S placed obliquely and the panels 12 are divided into
three triangular, smaller panels 13a, b and c folded
in under the sealing fin 10 to form so-called bellows
folds (one of which is shown at B in Figure lc). The
sealing fin consequently will comprise, at least in
its greater part, four material layers which are
joined to one another by means of a sealing operation
to form the configuration shown in figure lc. In case
both sides of the blank are coated with a plastics
: layer, e.g. polyethylene, this seal can be brought
about, for example, by heat sealing which means that
: the material layers in the sealing fin 10 of the
finished folded packing container are pressed against
each other with the help of heating sealing jaws in a
packing machine of the conventional type, as a result
~ 20 of which the plastic coatings on the heated sealing
: surfaces facing each other are fused together to form
a liquid-tight seal.
In accordance with the present invention a
~; : tearing indication 15 weakening the material layers is
arranged above the bellows fold ~ formed along a line
: between, and preferably parallel with, the top line
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~28591.6
10a and the foot line 10b of the sealing fin 10. The
tearing indication 15 i8 formed in accordance with
Figure la by a perforation 15p whose length on the
example chosen substantially corresponds to the length
05 of two whole package widths. On closing the packing
container by means of bellows folding, symmetrical in
relation to a crease line 8c, the different portions
of the perforation 15p are made to adjoin each other,
so that the tearing indication lS will extend from the
front edge 10c of the fin 10 substantially to the
centre of the fin ~Figure lc).
~ he perforation lS preferably can be arranged in
the central cardboard layer before the same is coated
with plastics layers and possibly with other layers
such as e.g. aluminium foil. The advantage gained
from such a procedure is that the packing material
will be liquid-tight, since the perforation holes or
perforation slots included will be covered by a
plastics layer.
The packing container shown in Figure lc is
opened~by means of folding out again the bellows fold
B so as to form an emptying opening 16 in the shape of
a pouring spout which is shown in Figure le. The
procedure here is that one pushes one's finger into
the openable bellows fold B and breaks the package
outwards towards the sides, as a result of whichthe
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1285916
perforation 15 is broken up and the sealing fin 10 in
the region below the tearing perforation 15 is
delaminated, whereas the corresponding region above
this perforation remains non-delaminated to attain the
05 condition shown in Figure ld. Subsequently the parts
of the sealing fin 10 so delaminated are pressed
together, as a result of which seals between these
parts are broken and the bellows fold B bulges
outwards so as to form the emptying opening 16 in the
shape of a pouring spout shown in Figure le.
With a view to facilitating the breaking up of
the seal between the inside surfaces 17-20 adjoining
one another of the bellows fold B folded flat (Figure
ld) and thereby facilitating the subsequent bulging
out of this bellows fold, these adjoining surfaces are
reduced in their sealing capacity in accordance with
the invention by a pretreatment of the corresponding
portions on the packing blank shown in Figure la.
These pretreated parts correspond to the hatched
region C in Figure la and comprise the part of the
edge zone 9 which is located between the tearing
perforation 15p or 15 and the upper crease line 7 and
are marked 17 to 20 in the figures shown. This
seal-reducing pretreatment may involve, for example,
the covering of the plastics layer with a coating
;~ inhibiting or weakening a seal (a so-called abhesive)
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~28S91.6
consisting of some siliceous compound, e.g.
polysiloxane rubber or a wax mateial of a type known
in itself.
In accordance with the invention it is preferred
S to reduce the seal of all adjoining surfaces below
the tearing perforation 15 in the sealing fin 10, that
is to say, not only the inside surfaces (17-20) on the
part of the sealing fin 10 forming the emptying
opening 16 but also the two outside surfaces 21,22 of
the rectangular end panel 12 above the fold-out
bellows fold B~ As a result of this, on opening the
packing container, the folding out of the bellows
fold to the plane condition shown in Figure lb, is
facilitated.
Through the combination of the tearing
perforation 15 arranged in the sealing fin 10 and the
said weakening of the seal of the inside surfaces
17-20 sealed in a detachable manner in the region C
below the tearing perforation a packing container is
obtained in accordance with the present invention
which eliminates the conflicting requirements
;; mentioned earlier with regard to easy openability and
at the same time reliable liquid-tightness and which
instead makes both these requirements well compatible
with each other.
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