Note: Descriptions are shown in the official language in which they were submitted.
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METHOD FOR APPLYING AN OPENING DEVICE TO A PACKAGING MATERIAL AND PACKAGE
OBTAINED THEREBY
TECHNICAL FIELD
The present invention relates to a method for
applying an opening device to a packaging material for
packaging pourable food products, and to a package
obtained thereby.
BACKGROUND ART
Many pourable food products, such as fruit juice,
UHT milk, wine, tomato sauce, etc., are sold in packages
made of sterilised packaging material.
A typical example of such a package is the
parallelepiped-shaped package for liquid or pourable food
products known as Tetra Brik or Tetra Brik Aseptic
(registered trademarks), which is formed by folding and
sealing laminated web packaging material. The packaging
material has a multilayer structure comprising a layer of
fibrous material, e.g. paper, covered on both sides with
layers of heat-seal plastic material, a.g, polyethylene.
In the case of aseptic packages for long-storage
CONFIRMATION COPY
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products, such as UHT milk, the packaging material also
comprises a layer of oxygen-barrier material defined, for
example, by an aluminium film, which is superimposed on a
layer of heat-seal plastic material and is in turn
covered with another layer of heat-seal plastic material
eventually defining the inner face of the package
contacting the food product.
As is known, such packages are made on fully
automatic packaging units, on which a continuous tube is
formed from the web-fed packaging material; the web of
packaging material is sterilized on the packaging unit
itself, e.g. by applying a chemical sterilizing agent,
such as a hydrogen peroxide solution, which, after
sterilization, is removed, e.g. vaporized by heating,
1S from the surfaces of the packaging material; and the web
of packaging material so sterilized is maintained in a
closed lsterile environment, and is folded and sealed
longitudinally to form a vertical tube.
The tube is filled continuously from the top with
the sterilized or sterile-processed food product, and is
sealed and cut at equally spaced cross sections to form
pillow packs, which are then folded mechanically to form
the finished, e.g. substantially parallelepiped-shaped,
packages.
Alternatively, the packaging material may be cut
into blanks, which are formed into packages on forming
spindles, and the resulting packages are filled with the
food product and sealed. One example of such a package is
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the so-called "gable-top" package commonly known by the
trade name Tetra Rex (registered trademark).
The above packages are normally provided with
reclosable opening devices to permit consumption of, and
prevent external agents from coming into contact with,
the food product in the package.
The opening devices most commonly used at present
comprise a frame defining a pouring opening and adapted
to be fitted to a hole or a punch-through or pull-off
portion in a wall of the package, and a lid hinged or
screwed to the frame and which is removable to open the
package. Alternatively, other, e.g. slide-type, opening
devices are also known to be used.
By e.g., WO 98/18608 and WO 98/18609, an apparatus
and a method is previously known relating to injection
moulding of a plastic material opening device to a hole
provided on a sheet of packaging material.
The above described opening devices are frequently
arranged on the top wall of the package. As is known, the
top wall of the package formed from the tube of packaging
material has a number of sealing bands which limit the
amount of space available in which to provide the opening
device. In particular, the top wall is crossed along the
centerline by a flat transverse sealing band folded down
onto and coplanar with the top wall, and by an end
portion of a flat longitudinal sealing band extending
perpendicularly from the transverse sealing band. More
specifically, the longitudinal sealing band extends along
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a portion of the top wall of the package, and downwards
from the top wall along a lateral wall and a bottom wall
of the package.
Likewise, spindle-formed packages also comprise a
S top wall crossed along the centerline by a flat
transverse sealing band folded down onto and coplanar
with the top wall.
In neither case can the opening device be fitted to
the sealing bands of the package, which would not only
pose problems in sealing the device onto an uneven
surface, but would also impair°the integrity of the seals
themselves.
The opening device can therefore only be fitted to
the limited flat portions adjacent to the sealing bands
extending across the top wall of the package, which
obviously limits the maximum size of the opening device.
The bigger the pouring hole the better the pouring
characteristics. Thus, there is a demand for bigger
opening devices giving better pouring, particularly in
view of the increasing number of physically different
products marketed in packages made of paperlike packaging
material, some of which, particularly semiliquid products
or products containing fibers or particles,, require a
larger opening device for the product to be poured
smoothly.
Furthermore, the opening device is normally arranged
at a distance from the crease lines defining the edges of
the top wall in order to avoid that the peripheral edge
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of the plastic frame disturbs the forming of the package.
The bigger the distance between the opening device and
the lateral edge of the top wall at the package pouring
side, the higher the risk that, during the pouring, the
5 liquid product spills along the adjacent side walls of
the package.
DISCLOSURE OF INVENTION
Tt is an obj ect of the present invention to provide
a method for applying an opening device to a sheet
packaging material for packaging pourable food products,
designed to provide a straightforward solution to the
aforementioned drawbacks typically associated with known
methods.
According to the present invention, there is
provided a method for applying an opening device to a
sheet packaging material for packaging pourable food
products, said packaging material comprising a plurality
of crease lines along which the packaging material itself
is folded to obtain a package filled with a pourable food
product, said opening device comprising a frame defining
a pouring opening and a movable lid for closing said
pouring opening, said method being characterized by
comprising the step of fitting said frame to said
packaging material in a position, in which it extends
across one of said crease lines defining an edge of said
package.
The present invention is also relative to a sealed
package for pourable food products made from a sheet
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packaging material having a plurality of crease lines,
said package being provided with an opening device
comprising a frame fitted to said packaging material and
defining a pouring opening, and a movable lid for closing
said pouring opening, characterized in that said frame
extends across one of said crease lines defining an edge
of said package.
BRIEF DESCRIPTION OF THE DRAWTNGS
A number of preferred non-limiting embodiments of
the present invention will be described by way of example
with reference to the accompanying drawings, in which:
figure 1 is a perspective view of an upper portion
of a sealed package for pourable food products in
accordance with the present invention;
figures 2, 3 and 4 are bottom plan views of
respective alternative embodiments of a frame of an
opening device of figure 1 package;
figure 5 is a top plan view of a packaging material
web portion to which one of the frames of the opening
devices of figures 2, 3 and 4 is to be applied to form
the figure 1 package;
figure 6 is a top plan view of the packaging
material web portion of figure 5 provided with the frame
of the figure 3 opening device;
figure 7 is a section view of the packaging material
web taken along line VII-VII of figure 6;
figure 8 is the section view of figure 7, after
folding of the packaging material web to form the figure
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1 package;
figure 9 is a perspective view of the upper portion
of a sealed package for pourable food products according
to another embodiment of the present invention;
figure 10 is a perspective view of the upper portion
of a sealed package for pourable food products according
to a further embodiment of the present invention; and
figure 11 is a larger-scale cross section of the
upper portion of the figure 10 package.
BEST MODE FOR CARRYING OUT THE INVENTION
Numeral 1 in figure 1 indicates as a whole a sealed
package for pourable food products, e.g. a
parallelepiped-shaped package known as Tetra Brik Aseptic
(~eglstered trademark), which is produced from a web 2 of
packaging material (shown only partly in figures 5, 6) as
described in more detail previously, and is provided with
a reclosable opening device 3 made of plastic material
and applied preferably to an upper portion of package 1.
Package 1 comprises a top wall 4, a base wall (not
shown) opposite top wall 4, a front wall 5, a back wall
(not shown), and a pair of side walls 6 (only one of them
is shown in figure 1).
The packaging material defining web 2 and package 1
has a multilayer structure (not shown), and comprises a
layer of fibrous material, normally paper, covered on
both sides with respective layers of thermoplastic
material, e.g. polyethylene. The side of the packaging
material eventually contacting the food product in
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package 1 may also have a layer of oxygen-barrier
material, e.g. aluminium, in turn covered with one or
more layers of thermoplastic material.
Web 2 includes a crease pattern 7, i.e. a plurality
of weakened lines. obtained by creasing rolls and forming
folding lines along which the material is folded during
the forming and final folding steps.
Preferably, package 1 is made from a continuous tube
(not shown) of packaging material, which is obtained by
bending and longitudinally sealing web 2 along lateral
edges thereof. More precisely, an edge portion of web 2
is superimposed and sealed onto the opposite edge portion
so as to obtain a longitudinal seal 8 which has an
intermediate portion extending ~ along a vertical
centreline of the back wall (non shown) of the finished
package 1 and opposite end portions extending along the
base wall and top wall 4 of the package itself.
The tube is then transversally sealed at regular
intervals to form transversal seals 9 which extend along
the base wall and top wall 4 of the finished package 1.
Afterwards, the tube is cut along transversal seals 9 to
form so-called pillow packs, which are intermediate
products adapted to be transformed into finished packages
1 by means of a plurality of final folding step.
With reference to figures 1, 6, 7, and 8, opening
device 3 comprises an externally threaded annular frame
10 defining a circular pouring opening 11 through which
to pour out the food product contained in package 1, and
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fitted to the upper portion of package 1 at a hole 12
thereof ( f figures 5 , 7 , 8 ) ; and a 1 id or cap 13 , which i s
formed separately from frame 10 and is screwed to frame
in a closed position closing pouring opening 11. Once
5 opened, cap 13 is movable between said closed position
and an open position detached from frame 10.
In particular, hole 7 is punched through web 2 and
opening device 3 is fitted to the packaging material
before web 2 enters forming, filling and sealing sections
10 of a filling machine (not shown), wherein web 2 is bent
and longitudinally sealed to obtain the above mentioned
vertical tube to be filled with the pourable food
product.
According to the present invention, hole 12 and
frame 10 of opening device 3 extend across a crease line
14 defining an edge of package 1; in the embodiment shown
in figure 1, crease line 14 defines an horizontal edge 15
of package 1 dividing top wall 4 from front wall 5.
Frame 10 of opening device 3 is preferably formed by
injecting plastic material through hole 12 and between
two mould elements (not shown) cooperating with each
other on opposite sides of web 2, so that frame 10 embeds
an edge of hole 12 thereby preventing opening device 3 to
be removed from hole 12.
In particular, during the injection moulding
process, the thermoplastic coating of web 2 melt and
coalesce with the plastic material of frame 10 at hole
12.
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Alternatively, frame 10 of opening device 3 may be
attached to the packaging material of web 2 by means of
gluing or welding through heating elements or ultrasonic
sealing elements.
5 With reference to figures 1-4, 7 and 8, frame 10
comprises a flat annular flange 16 fitted to top and
front walls 4, 5, and a cylindrical, externally threaded,
annular portion 20 projecting from an internal edge of
flange 16 and defining pouring opening 11.
10 Flange 16 comprises a circular main portion 21 and a
rectangular lateral flap 22 protruding in a coplanar
manner from a side of main portion 21. Pouring opening 11
of annular portion 20 is preferably covered by a tear-off
seal 23.
During forming operations of package d, flange 16 is
bent over crease line 14 so as main portion 21 extends
along top wall 4 between crease line 14 and relative
transversal seal 9, whilst flap 22 extends along front
wall 5.
To facilitate the bending of flap 14, flange 16 is
provided with a notch, three different embodiment s
thereof are shown in figures 2, 3 and 4 and are
referenced respectively with numerals 24a, 24b, 24c. Each
notch 24a, 24b, 24c extends between flap 22 and main
portion 21 and is designed to be placed over crease line
14.
Notch 24a has a straight shape parallel to crease
line 14, notch 24b has a hourglass shape and notch 24c
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has a shape resembling an hourglass but where the narrow
middle part follows the circumferential external profile
of annular portion 20 of frame 10.
Straight notch 24a of figure 2 gives the possibility
to increase the diameter of pouring opening 11 compared
to notches 24b, 24c; however, frame 10 must be placed
exactly so that notch 24a comes over crease line 14.
The positioning of hourglass-shaped notch 24b in
relation to crease line 14 is less critical. In fact, as
long as crease line 14 is placed inside the outer limits
of notch 24b, frame 10 will bend at said notch. Depending
on the position of crease line 14 in relation to notch
24b, package l may bulge slightly inwards or outwards at
frame 10. This bulging is hardly noticeable at a casual
observation.
Notch 24c has an hourglass like form. The intention
is that crease line 14 should be in line with the broader
end parts of notch 24c, which means that frame 10 will
slightly protrude with respect to~edge 15 of package 1,
as shown in figure 8. In this case, pouring opening 11
may have a larger diameter as it may be placed more
closely to or even projecting from crease line 14;
therefore, there is less risk of the food product to
spill on front wall 5 of package 1 during the pouring.
As shown in f figure 5 , hole 12 has the same prof file
as flange 16 of frame 10; the outer dimension of hole 12
is somewhat smaller than the outer dimension of flange 16
of frame 10. Thus, when flange 16 of frame 10 is placed
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over hole 12, the peripheral edge of flange 16 will
overlap hole 12. Hole 12 is placed mainly in the part of
the web 2 designed to form top wall 4 of package 1, and
has an end portion formed in the part of web 2 designed
to form front panel 5. As above mentioned,' hole 12
crosses crease line l4 positioned between top wall 4 and
front wall 5.
With reference to figures 1 and 6-8, cap 13
comprises, integrally, a circular portion 25 closing
pouring opening 11, and a cylindrical, internally
threaded, annular portion 26 projecting from a circular
outer peripheral edge of circular portion 25 and which
screws onto annular portion 20 of frame 10.
Figures 9, 10 and 11 show the basic principle of the
present invention applied to packages 1~, 1 " which will
be described only insofar as they differ from package 1
and using the same reference numerals for any parts
similar or corresponding to those already described.
With reference to figure 9, package 1' differs from
package 1 for having a curved front wall 5' and therefore
a curved crease line 14', and consequently a curved edge
15' , dividing the front wall itself from a top wall 4' .
Package 1' is provided with an opening device 3' which is
completely similar to opening device 3 and whose parts
are referenced with the same numerals of corresponding
parts of opening device 3. Frame 10 of opening device 3'
has a notch (not shown), which may be shaped as notch
24a, 24b, 24c, is located at said curved crease line 14'
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and is imparted with a corresponding curved
configuration. Both curved crease line 14' and said
curved configuration of the notch of frame 10 of opening
device 3' are convex. In all other respects package 1'
and opening device 3' of the embodiment of figure 9
correspond to package 1 and opening device 3 discussed
above. Thus, frame 10 of opening device 3' comprises a
flat annular flange 16' extending across crease line 14'
and having preferably a main portion 21' arranged on top
wall 4' and a flap 22' arranged on front wall 5'.
With reference to figures 10 and 11, package 1 "
differs from package 1 only for being provided with an
opening device 3 " of the "hinged-type".
Package 1 " has a parallelepiped shape and is
delimited by a plurality of walls referenced with the
same numerals of the corresponding walls of package 1.
Opening device 3 " comprises a frame 30 defining a
pouring opening 31 and fitted to an upper portion of
package 1 " at a hole 32 thereof, and a lid 33 connected
to frame 30 by a hinge 34 defining an axis A parallel to
top wall 4.
Hole 32 and frame 30 of opening device 3 " extend
across a crease line 35 defining an edge of package 1"
parallel to axis A; in the embodiment shown in figures 10
and 11, crease line 35 defines an horizontal edge 36 of
package 1 " dividing top wall 4 from an adjacent side
wall 6.
Lid 33 is moulded integrally with frame 30.
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Also in this case, opening device 3' ' is preferably
applied to a packaging material web at a hole 32 thereof
before the web enters forming, filling and sealing
sections of a filling machine (not shown), wherein the
finished package 1 is formed.
In particular, opening device 3" is preferably
formed by injecting plastic material through hole 32 and
between two mould elements (not shown) cooperating with
each other on opposi-to sides of the packaging material
web,.so that frame 30 embeds a peripheral edge of hole 32
thereby preventing opening device 3 " to be removed from
hole 32. More specifically, frame 30 forms a
substantially flat, annular base flange 37, which rests
on a first face 39 of the packaging material adapted to
define an internal surface of package 1" , and a
plurality of coplanar fins 38 extending on a plan
parallel to base flange 37 and resting on a second face
40 of the packaging material opposite first face 39.
Alternatively, frame 30 of opening device 3" may be
attached to the packaging material by means of gluing or
welding through heating elements or ultrasonic sealing
elements.
Frame 30, pouring opening 31 and lid 33 have
respective shapes elongated in the direction of
transversal seal 9 of top wall 4.
Frame 30 further includes a raised annular neck 41
extending from base flange 37 and delimiting pouring
opening 31.
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Base flange 37 of frame 30 is bent over crease line
35 so as a substantially rectangular.-shaped main portion
42 of base flange 37 extends along top wall 4, and a
tapered end portion 43, opposite hinge 34, of the base
5 flange itself extends along side wall 6; tapered end
portion 43 is substantially V-shaped and presents a
rounded vertex.
To facilitate the bending of frame 30 over crease
line 35, base flange 37 has a notch (not visible) which
10 may be shaped as notch 24a, 24b, 24c of opening device 3
and extends along a bottom surface of the base flange
itself.
Neck 41 forms a flat top flange 45 having a
substantially rectangular shape and protruding with
15 respect to the neck itself.
Lid 33 comprises a flat main portion 46, which is
connected to frame 30 by hinge 34, and a raised
substantially U-shaped sealing lip 47 extending from the
ends of hinge 34 and projecting from main portion 46 for
engagement with neck 41. Lid 33 is originally sealed to
an internal edge 44 of top flange 45 of frame 30
surrounding pouring opening 31 by a thin breakable rib 48
extending along a peripheral line around lip 47, and
which is broken when lid 33 is unsealed.
Internal edge 44 of top flange 45 of frame 30 and
lip 47 of lid 33 are conveniently so shaped as to define
a cusp shaped pouring beak 50.
At pouring beak 50, top flange 45 defines a pouring
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spout 51 projecting from the neck 41 over crease line 35.
Once unsealed, lid 33 is movable between an open
position (figure 10) and a closed position (figure 11) ,
in which lip 47 of lid 33 is retained in fluid-tight
manner inside neck 41 of frame 30 by rib 48 snapping
beyond edge 44.
At its opposite end to hinge 34, lid 33 forms a pull
tab 52 which protrudes outwards with respect to pouring
opening 31 at crease line 35 side and faces with base
flange 37 of frame 30. Tab 52 defines a handle portion of
lid 33 adapted to be pulled upwards by the consumer so as
to raise lid 33 and reach open position. Tab 52 is bent
towards side wall 6 and is integrally connected at its
free end to end portion 43 of base flange 37 by a
breakable strip 53 defining a tamper evidence. When tab
52 of lid 33 is pulled upwards, the strip 53 is broken so
as to permit the opening of package 1 " .
The advantages of the method according to the
present invention and of package 1, 1', 1 " will be clear
from the foregoing description.
In particular, thanks to the fact that frame 10, 30
of opening device 3, 3', 3 " extends across crease line
14, 14', 35 or edge 15, 15', 36 of package 1, 1', 1 " ,
pouring opening 11, 31 of opening device 3, 3', 3 " is
positioned immediately adjacent to the above mentioned
edge 15, 15', 36, so as to improve the pouring of the
food product and to minimize the risk that such product
will spill on the walls (5, 5', 6) beneath the pouring
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opening itself .
Since opening device 3, 3', 3 " can cross edge 15,
~15', 36 of package 1, 1', 1 " , more space is available on
top wall 4, 4' for accommodating the opening device
itself. This means bigger opening devices, with bigger
pouring openings, leading to improved pouring.
The positioning of opening device 3, 3', 3" over
edge 15, 15', 36 of package 1, 1', 1 " reinforces the
edge itself, where it is most vulnerable to damage during
transportation and handling.
The positioning of opening device 3, 3', 3" over
edge 15, 15', 36 of package l, 1', 1 " also provides a
package which is more pleasant to drink from directly,
because it provides a better "lip feel", i.e., the Zips
of a consumer do not contact the packaging material, but
only the plastic. Consumers in some countries are known
to appreciate this improvement.
Packages 1, 1', 1 " are less susceptible to errors
of positioning of opening device 3, 3', 3 " with respect
to adjacent edge 15, 15', 36, since the folding of the
packaging material along crease line 14, 14', 35 defining
the edge itself is driven by the bending of plastic frame
10, 30 of opening device 3, 3', 3 " .
Finally, in the case of package 1" , the peripheral
edge of end portion 43 of base flange 37 rests on
vertical side wall 6, so increasing the resistance of
pouring beak 50 to external loads, such as loads deriving
from transportation and handling, on protruding pull tab
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52.
Clearly, changes may be made to the method and
package l, 1', 1 " as described and illustrated herein
without, however, departing from the scope of the
accompanying claims.
