Note: Descriptions are shown in the official language in which they were submitted.
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A PACKAGE CONTAINER, PACKAGING LAMINATE AND THE USE OF
A COLOUR PRINT
TECHNICAL FIELD
The present invention relates to a flexible packaging container of a
transparent packaging laminate, containing a coloured, liquid food product,
the
packaging container displaying, on a front and/or rear display surface, a
colour print
applied directly thereon. The present invention also relates to a packaging
laminate
for the packaging container, as well as to the use of a colour print on such a
packaging laminate.
BACKGROUND ART
There is a growing demand on the market today for packages for beverages
and liquid foods of the single-use bag type in plastic, these bags preferably
being at
least partly, on some region of the package, transparent so that they show to
the
consumer the contents of the package when they are exposed on the shelf, for
example in a food hall. Usually, such packages are provided with a drinking
straw so
that the consumer may consume the contents direct, or a pull tab for opening
and
pouring out the contents.
One example of a transparent packaging laminate for such a packaging
container is described in PCT/SE2003/001750.
One problem inherent in packaging containers of a transparent and flexible
packaging laminate is to be able to provide it with a distinct and clear
colour print.
According to the prior art technology, attempts have been made to create, by
using a
subjacent white colour layer, an opaque background for the colour print so
that the
colour print, in the form of text and/or artwork will be able to show clearly
beside
portions of the packaging/packaging laminate which lack print and where the
product
is thus displayed. If however the food product is coloured, its colour has a
tendency
to show through the subjacent, white, opaque colour layer and the upper colour
layer
so that the visible impression will be that the text /the artwork is
miscoloured and
diffuse. As a result, the package with its contents has difficulty in
competing on the
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shop shelf with, for example, metal foil-based flexible packages showing
highly
distinct and clear print.
It is, therefore, one object of the present invention to offer a packaging
container and a packaging laminate which obviate the above-discussed drawbacks
and problems.
It is a further object of the present invention to offer a flexible packaging
container of a transparent packaging laminate containing a coloured, liquid
food
product, the packaging container displaying, on a front and/or rear display
surface, a
colour print directly applied thereon, the colour print giving a distinct and
clear
visible impression despite the impact of the coloured food product.
It is yet a further object of the present invention to offer a transparent
packaging laminate possessing gas barrier properties which are suitable for
aseptically packed and long shelf-life storage, as well as displaying
sufficient
flexural rigidity to be suitable for the continuous high speed packing of
liquid foods
by means of a continuous tube forming process and which moreover has a colour
print which gives a distinct and clear visible impression even in the packing
of a
coloured, liquid food product in a packaging container which is produced from
the
packaging laminate.
BRIEF SUMMARY OF THE INVENTION
The above-outlined objects are attained by offering a flexible packaging
container of a transparent packaging laminate containing a coloured, liquid
food
product, the packaging container displaying, on a front and/or rear display
surface, a
colour print directly applied thereon, at least selected portions of said
colour print
being a transparent colour print which permits transparency for the food
product and
one or more colour shades in the transparent colour print being selected so
that the
visible impression thereof is enhanced or modified in cooperation with the
colour of
the food product proper.
The solution to the above-mentioned problems and needs is thus, instead of
attempting to counteract the transparency effects of the colour print, for
example by
applying a white colour layer affording opacity beneath the text/artwork, to
utilise
the transparency of the colour print in order, in cooperation with the colour
of the
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food product proper, to give a distinct, clear and attractive visible
impression. The
visible impression of the colour print can be enhanced or modified by the
cooperation with the colour of the food product. Moreover, there will be
obtained a
three-dimensional effect by the cooperation of the colour of the food product,
the
transparent packaging laminate and the transparent colour print.
According to one aspect of the present invention, the transparent colour print
has an opacity of greater than 3, preferably greater than 4 and more
preferably
greater than 5. An upper limit is in principle set by the value of a totally
transparent
film without colour print and, therefore, the opacity level is in practice at
most 13,
preferably at most 12 and most preferably at most 11. Thus, the value 1
signifies total
opacity and the higher the value, the greater will be the transparency. The
measurements are carried out using a reflectometer which measures in
accordance
with ISO 6504/AST E97/DIN 55984 and the opacity is calculated as the
relationship
between reflectance of a measurement object on a white background to
reflectance of
the measurement object on a black background with an angle of impingement of
45
and a reflection angle of 0 .
It is thanks to the low opacity and the absence of colour layer affording
opacity that the possibility of cooperation with the coloured food product is
attained
in the selected portions carrying transparent colour print.
According to another aspect of the present invention, the transparent colour
print constitutes a background for an artwork- or text print which is disposed
on the
same display surface. The background, which may be printed with different
colour
densities, permits the display of the coloured food product in a different and
more
attractive manner than prior art packages of transparent, flexible packaging
laminate
where a background is totally absent in order that the food product be visible
in the
regions between text/artwork.
According to yet a further aspect of the present invention, the transparent
colour print is a photographic print. It is to be preferred that this be
applied by means
of a so-called process or screen printing technique, preferably with varying
density
between the half tone dots in order to obtain different colour intensities in
one and
the same artwork or one and the same background to artwork and/or text.
Employing
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the process/screen technique, the entire colour spectrum can be obtained from
four
primary subtractive colours, viz. cyan, magenta, yellow and black. However, it
is
also conceivable to utilise other printing techniques where printing inks are
mixed in
different shades and are applied. Examples of useable printing techniques are
flexo,
flexo process, off-set or rotogravure. One advantage is that the application
of a
transparent colour print is eminently suitable for solvent-free printing
inks/techniques, since less ink quantities are consumed for a transparent
colour print
than for an opaque colour print. The reason for this is that, for creating an
opaque
colour print with larger ink quantities, solvents are often needed to attain
satisfactory
results.
According to still a further aspect of the present invention, the transparent
colour print forms a complete piece of artwork or part thereof. For example, a
fruit,
berry or vegetable representative artwork can be formed as a transparent
colour print
according to the present invention, in which event the visual impression of
this
printing ink is enhanced or modified in cooperation with the colour of the
food
product proper.
According to yet a further aspect of the present invention, the front and/or
rear display surface may also display colour print which is directly applied
thereon in
-selected areas and which affords opacity, arid preferably constitutes a text
and/or a
piece of artwork and preferably includes a subjacent white colour layer and an
upper
colour layer. This print will then constitute a substantially opaque piece of
artwork
and/or text on a background of the transparent colour print according to the
present
invention.
According to still a further variation, the transparent colour print is
applied at
least on the front display surface of the package, while a transparent colour
print or a
transparent or opaque artwork or opaque text print is disposed on its rear
display
surface, so that the transparent colour print or artwork or text print on the
rear display
surface clearly appears through both the coloured food product proper, the
front
display surface and its transparent colour print. As a result, an "aquarium
effect" can
for example be obtained, or information such as slogans, so-called "fortune
cookies"
etc. can be read through both the coloured food product, the front display
surface and
its transparent colour print.
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According to still a further aspect of the present invention, said transparent
colour print is of the same colour as the food product, but of a different
shade,
whereby the visual impression of the transparent colour print is enhanced in
cooperation with the colour of the food product proper. For example, a visual
5 impression with more life can be obtained from a blue coloured food product
in a
transparent packaging container with a blue, transparent colour print. If the
colour
print is moreover photographic and displays different degrees of colour
density
and/or different shades of blue, water-like effects can, for example, be
achieved
including bubbles, foam, water swell or the like.
According to yet a further aspect of the present invention, said transparent
colour print is of a different colour than the food product, whereby the
visual
impression of the transparent colour print, in cooperation with the colour of
the food
product proper, is modified to a third colour. One example is that a yellow
food
product, such as orange juice, together with a red, transparent colour print
of varying
colour density, gives an orange visual impression which, for example, may
represent
the citrus fruit. Another example is that a yellow product in a packaging
container
with a blue, transparent colour print makes a green visual impression.
The packaging laminate for the package according to the invention preferably
includes a gas barrier layer. More precisely, it preferably includes an
outside layer of
thermosealable olefin polymer, a first gas barrier layer of SiOx, coated on a
first
polymer carrier layer, and a second gas barrier layer of SiOx, coated on a
second
polymer carrier layer, as well as an interjacent polymer layer of greater
thickness in
relation to each one of the surrounding layers which is laminated between the
two
gas barrier-coated carrier layers. A well functioning packaging laminate of
this type
is described in PCT/SE2003/001750, whose contents are hereby incorporated
herein
by reference.
However, the present invention is not restricted to being utilised in
connection with such a laminate. For example, it is conceivable to employ a
transparent packaging laminate with low gas barrier properties, in which event
use is
instead made of a preserving agent in the product. Other variations of
transparent
packaging laminates are also conceivable.
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One preferred variation of the package according to the invention consists of
a flexible bag which is fold-formed at the bottom, preferably of portion size
and with
a hole for a drinking straw or an opening arrangement. The packaging container
according to the invention is a bag or a "standing bag" or the like and is
durable on
handling and distribution and resistant to moisture and oxygen gas during long-
term
storage, because of the high quality packaging laminate, which in turn also
imparts a
high level of quality to seals and enjoys excellent gas barrier properties. A
further
crucial advantage in packaging containers produced from the packaging laminate
according to the invention is that they withstand boiling or thawing by means
of
microwaves, as well as retorting.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Further advantages and advantageous, characterising features of the present
invention will be obvious on the basis of the following detailed description
and with
reference to the accompanying Drawings. In the accompanying Drawings:
Fig. 1 is a cross sectional view of a preferred laminated packaging material
according to the present invention; and
Fig. 2 shows one preferred example of a packaging container which has been
produced from the packaging laminate according to the present invention.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS AND
PREFERRED EMBODIMENT
Fig. 1 thus shows a transparent packaging laminate 10 including a first and
second carrier layer 11; 12 which are films of a preferably prefabricated film
of
polyester or polyamide, such as a moulded film or preferably a mono- or
biaxially
oriented polyethylene terephthalate (PET), polyethylene naphthenate (PEN) or
polyamide (PA), on which coatings of a thin gas barrier layer of SiOx 13; 14
have
been applied. The SiOx layer is preferably applied by means of plasma enhanced
chemical vapour deposition, PECVD, where x = 1.7 - 2.0, of a thickness of from
about 50 to about 500 A, preferably from about 80 to about 300 A. The two SiOx
layers are preferably turned to face towards the interior of the laminate and
thus face
towards one another.
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Between the two carrier layers which are coated with gas barrier layer, an
interjacent layer 15 is laminated. The interjacent layer 15 may consist of a
relatively
rigid olefin polymer, such as, for example, high density polyethylene (HDPE)
or
polypropylene (PP), or alternatively of a polymer which is soft and/or has
elastomeric properties, such as, for example, polyethylene of very low density
(VLDPE) or polyethylene of ultra low density (ULDPE). Another alternative is
that
the interjacent layer 15 consists of a mixture of high density polyethylene
(HDPE)
and polyethylene of very low density (VLDPE) or polyethylene of ultra low
density
(ULDPE). Yet a further alternative is that the interjacent layer 15 is built
up from at
least two, preferably three sublayers of high density polyethylene (HDPE) and
polyethylene of very low density (VLDPE) or polyethylene of ultra low density
(ULDPE). The interjacent layer is thicker than any of the surrounding layers
in the
packaging laminate and thereby serves as a spacer element between the two
carrier
layer films of oriented polymer. However, the thickness of the interjacent
layer does
not constitute more than from about 30 to about 55 % of the total thickness of
the
packaging laminate, more preferably from about 35 to about 50 %. Preferably,
the
thickness of the carrier layers constitutes from about 5 to about 20 %, more
preferably from about 5 to about 15 % of the total packaging laminate.
On the outside of the carrier layer 11 that will constitute the outside wall
in a
packaging container which is produced from the packaging laminate, at least
one
layer 16 of a thermosealable olefin polymer, preferably a low density
polyethylene
(LDPE) or a linear low density polyethylene (LLDPE) is applied and also
includes
so-called metallocen catalysed LLDPE (m-LLDPE), i.e. LLDPE polymers catalysed
by means of a single seat catalyst. Other examples of alternative polymers for
the
outside layer in the packaging wall may be a polyethylene of medium high
density
(MDPE) or polypropylene (PP).
On the outside of that carrier layer 12 which will constitute the inside wall
in
a packaging container produced from the packaging laminate, there is applied
at least
one layer 17 of a thermosealable olefin polymer, preferably a layer of LDPE or
more
preferably a layer of LLDPE and most preferably a first sublayer 17a of LDPE
and a
second, outer sublayer 17b of LLDPE.
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The outside layers 16, 17 are each applied in a quantity of from about 10 to
about 25 m in order to obtain optimum thermosealing properties in relation to
cost
efficiency.
For optimal adhesion between the different layers in the packaging laminate,
use is preferably made of a tie layer of adhesive polymers, tie layers and
primers
which are known in the art. Such tie layers and primers are adapted to the
specific
choices of polymer in the different layers and may be selected from
polyolefins and
modified polyolefins, preferably polyethylene-based polymers, such as, for
example,
I.DPE and modified LDPE.
In the tie layers 18, 19 between the layers of SiOx 13; 14 and the interjacent
polyolefin layer 15, use is preferably made of a polyethylene base polymer
which is
inoculation modified by means of an unsaturated alkoxy silan compound as
described in USPS 5,731,092 which is hereby incorporated herein by reference.
See
in particular column 1 line 39 to column 3 line 21 and Examples 1 and 2.
Other examples of tie layers are homo- or copolymers of LDPE or inoculated
copolymers of polyethylene, inoculated with monomers which include functional
groups of carboxyl- or glycidyl type, such as acrylic monomers or maleic acid
anhydride monomers (MAH), for example ethylene (meta) acrylic acid copolymers
(E(M)AA), ethylene, glycidyl (meta) acrylate copolyrriers (EG(M)A) or MAH
inoculated polyethylene (MAH-g-PE).
Any of the above discussed polymers whatever may also be employed in
possible tie layers 20; 21 between the outer, thermosealable polyolefin layers
16; 17
and the polymer carrier layers 11; 12.
The colour print according to the present invention is applied in conjunction
to layer 16 of a thermosealable olefin polymer on that side of the packaging
laminate
which will constitute the outside wall in a packaging container produced from
the
packaging laminate. Fig. 1 shows three variations of where this colour print
can be
applied. Furthest to the right is shown the preferred embodiment that the
colour print
26a is applied on the tie layer 20 (or direct on the carrier layer 11),
whereafter the
outside layer 16 is laid thereon. As a result, the colour print is protected
against wear
etc. by the layer 16. In the central illustration is shown a less preferred
variation
where the colour print 26b lies outside the outside layer 16. Furthest to the
left is
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shown yet a further preferred variation where the outside layer 16 consists of
two
sublayers 16a and 16b, the colour print 26c being applied on the inner 16a of
these
and the outer 16b of the sublayers is thereafter applied as protection for the
colour
print. A certain positive, visual gloss-look effect is also obtained by such
means.
Fig. 2a and 2b show a preferred example of a packaging container 25
containing a coloured, liquid food product, the packaging container having
been
produced from the packaging laminate 10 according to the present invention.
The
packaging container is particularly suitable for small drink packages for
direct use by
means of a drinking straw or the like. One such packaging container typically
has a
volume of about 330 ml or less, preferably from about 100 to about 250 ml, for
example about 125 ml, 200 ml or about 250 ml. It may be a bag of any
configuration
whatever, but is preferably cuneiform 21 so that it is simple to handle and
dimensionally stable when placed on a shelf in the food hall or on a table or
the like.
In order to realise such a "cuneiform" configuration, the bottom portion 22 of
the
package is formed so that the transverse thermoseal 24 in the bottom is
concealed
under the triangular corner flaps 23 which are folded and sealed against the
bottom
of the package.
The variation of the packaging container 25a in Fig. 2a has a colour print
directly applied "on the packaging container on a front display surface 27,
the colour
print including artwork, for example in the form of an orange 28 with leaves
29, a
background 30 and a text 31. In the example, the orange artwork 28 is a
transparent
colour print according to the invention, suitably in a red shade. When the
contents, an
orange juice, is yellow the visual impression of the artwork 28 will be
modified to
become orange, in cooperation with this yellow orange juice. The orange leaves
29
are formed from a transparent colour print according to the invention,
suitably in a
blue shade. When the contents are, as was mentioned above, yellow, the visual
impression of the artwork 29 will be modified in cooperation with this yellow
orange
juice, so that the orange leaves appear as green.
The background 30 is also formed from a transparent colour print according
to the invention, for example with a yellow shade which is
enhanced/intensified in
cooperation with the yellow contents of the packaging container.
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On the other hand, the text 31 on the packaging container 25a is made from a
colour print affording opacity, preferably including a subjacent white colour
layer as
well as an upper colour layer.
A hole 37 for a drinking straw is also shown on the packaging container 25a.
5 The variation of the packaging container 25a in Fig. 2a also has a colour
print
32 applied directly on the packaging container on a front display surface 27,
the
colour print being a transparent colour print according to the invention, in
this case
with a blue shade and representing waves and bubbles. When the contents of the
packaging container 25b are blue, the visual impression of the colour print
will be
10 enhanced/intensified in cooperation with these contents.
On the rear display surface 33 of the packaging container, there is disposed
artwork 34, in this case a starfish which may be of opaque character and which
clearly appears through both the coloured food product, the front display
surface 27
and its transparent colour print 32. The background 35 to the artwork 34 is
also
disposed on the rear display surface 33 and may consist of a transparent
colour print
according to the present invention, or may be a colour print of an opaque
character
which is also seen through both the coloured food product, the front display
surface
27 and its transparent colour print 32, which can give an "aquarium-like"
effect.
There may possibly be provided a text 36 on-the rear display surface 33 which
also
clearly appears through both the coloured food product, the front display
surface 27
and its transparent colour print 32.
An opening arrangement 38, in this case a pull tab, is also shown on the
packaging container 25b.
Finally, it should be observed that the present invention, which has been
described above with specific reference to the accompanying Drawings, is not
restricted to these embodiments which have merely been described and shown by
way of constituting examples, and that modifications and alterations which are
obvious to a person skilled in the art are possible without deviating from the
inventive concept as this is apparent from the appended Claims.
