Field of Application
[0001] The present invention relates, in its more general aspect, to the technical field
of food packaging.
[0002] In particular the invention relates to a packaging for containing a fluid or liquid
food product sensitive to light radiation, such as for example milk or fruit juice.
Prior Art
[0003] In the field of food packaging the need of guaranteeing a correct preservation of
the product is particularly felt.
[0004] The expression "correct preservation" here is used to indicate that the food product,
during the period of time that passes between packaging and consumption, preserves
its nutritional properties and organoleptic characteristics at best.
[0005] In the case of a fluid or liquid food product sensitive to light radiation, such
as for example milk, yoghurt or fruit juice, undesired phenomena of degradation can
be induced in the product due to exposure to the above radiation.
[0006] In particular, the light radiation can generate two types of effect:
Photochemical effect
[0007] In the sun light violet and ultra-violet radiations, i.e. those having low wavelength
and thus high energy, are the more efficient; they have enough energy to activate
some molecules of the food product which determine undesired chemical reactions.
[0008] Obviously, different products have different sensitivities to degradation through
light radiation due to the different absorbing power for the considered radiation
the molecules of the product itself do have.
Ionizing effects
[0009] Ionization is the formation of ions through subtraction of electrons from the atoms
of the molecules which are struck by the light radiation as target.
[0010] The ionizing radiations perform an action on the food product similar to that of
the ultra-violet rays; the extension of the action depends on the radiation energy.
[0011] The above degradation phenomena, i.e. the alterations of the product, can be thus
linked to the amount of light (light intensity and exposure duration) to which the
product is exposed, to the wavelength of the light radiation, to the exposure temperature
besides, as already said, the absorbing power for the considered radiation which the
molecules of the product itself do have.
[0012] In milk, in particular, greater alterations are found for exposures to radiations
having wavelength lower than 550 nm.
[0013] Additionally, products destined to a long shelf-life, such as for example UHT milk
or long-life milk, can be subjected to oxidation reactions which, although developing
more slowly than the degradation induced by light, bring about an undesired alteration
of the taste.
[0014] The packaging, thus, in order to ensure a correct preservation of the product contained
therein, also has to guarantee a good resistance to the passage of oxygen.
[0015] The known technique for packaging a food product of the type here considered provides
several solutions.
[0016] The more recurrent one is that of adopting polycoupled containers, i.e. made of more
layers of different material, of which at least one is opaque to light.
[0017] The more known example is that of Tetra Pak® containers wherein, between a polyethylene
film and a cardboard layer, an aluminium sheet is interposed having the function of
protecting from light radiation.
[0018] A packaging of this type is obtained by welding the polycoupled material, and it
can be realised without opening, also the access to the product contained therein
takes place, in this case, by cutting a corner of the container of the packaging or
by providing the packaging with a closing with a small cap or a tab.
[0019] Although advantageous under several aspects, a solution of this type has some drawbacks,
the main of which are given by, if the packaging lacks a closing system, the impossibility
of closing the packaging once it has been opened and the consumption of the product
has started, or by the compromised versatility of the packaging ensured by the same
closing system.
[0020] The process of separation, for a subsequent recycling, of the different materials
used for realising the packaging is also complex.
[0021] Among containers of the bottle type, the more used packages for protecting the food
product from light radiation are those made of more layers of plastic material having
different characteristics and colours, generally a light colour for the external layers
and black for the more internal layer, which constitutes the barrier-to-light system.
[0022] Those bottles realised by co-extruding and blowing high density polyethylene (HDPE)
or bottles of polyethylene terephthalate (PET) obtained starting from multilayer pre-moulds
wherein colourings and/or additives are added to the PET polymer belong to this type
of bottles.
[0023] Although meeting the aim, also packages of this type are not exempt from having drawbacks.
[0024] Besides the poor barrier to oxygen given by polyethylene, the main limit of these
packages stays in their layered structure which makes them particularly difficult
to be realised; in particular the method for obtaining layered pre-moulds is complex,
besides being expensive.
[0025] In this regard, it is to be observed that the public of consumers pay particular
attention to the cost of those food products, such as milk, considered as of first
need.
[0026] It results that, preferably, a packaging destined to contain such a product must
have a realisation cost which does not account, for a considerable percentage, on
the cost of the product.
[0027] Thus, preferably, the packaging must be structurally simple so as to ensure a low-cost
manufacture thereof.
[0028] It is further to be observed that for containing milk and similar widely consumed
food products, packages having a low environmental impact are considerably preferred
by the public of consumers and meet the European directions in the field, i.e. packages
realised through an eco-efficient method and being partially or wholly recyclable
at the end of their use.
Summary of the invention
[0029] The technical problem underlying the present invention is that of devising a packaging
for containing a fluid or liquid food product with such characteristics as to overcome
the cited drawbacks, i.e. such as to provide a high protection from ultra-violet radiation
and a high resistance to the passage of oxygen, thus guaranteeing a prolonged shelf
life and which is in the meantime particularly simple from the structural point of
view, as well as cheap and eco-efficient.
[0030] The above problem is solved, according to the present invention, by a packaging for
food products of the type here considered, comprising a container of plastic material
including a bottom, a side wall, a mouth, a cap closing said mouth and a film of plastic
material externally tied to said side wall, characterised in that said film is metallized
on at least one side thereof.
[0031] Preferably, the above film of plastic material is of the so-called thermoshrinking
type.
[0032] Further, preferably, the above film of plastic material is metallized on the sole
side facing the above wall of this container.
[0033] Advantageously, the above container and the above film are made of the same plastic
material, preferably polyethylene terephthalate.
[0034] Further, advantageously, the above metallized film covers the side wall of the container
and it can possibly extend to cover at least one portion of the above closing cap
and at least one portion of the above bottom.
[0035] Preferably, the above metallized film comprises an aluminium layer on the above side
facing the side wall of the container, this aluminium layer having a thickness comprised
between 10 nm and 20 nm, preferably 15 nm.
[0036] In a varying embodiment, the packaging according to the present invention further
comprises a lid of plastic material opaque to light radiation associated with the
above bottom of the container and peripherally equipped with an edge projecting on
top for covering a lower end portion of the above side wall of the container.
[0037] The present invention also relates to a method for obtaining a packaging for fluid
or liquid food product sensitive to light radiation, comprising the application of
a film of plastic material metallized on at least one side thereof on the side wall
of a container substantially bottle-like shaped and filled in with such a product.
[0038] Advantageously, this film is thermoshrinking, it is made in the form of a sleeve
and it is applied by putting the sleeve on the container and by subsequently inducing
the sleeve shrinking through exposure to heat.
[0039] The advantages and characteristics of a packaging for fluid or liquid food products
according to the present invention will be more apparent from the following description
of an embodiment thereof given by way of indicative, non limiting example with reference
to the annexed drawings.
Brief description of the drawings
[0040] In these drawings:
Figure 1 schematically shows a perspective view of a packaging for food products according
to the invention.
Detailed description
[0041] With reference to figure 1, a packaging for containing a fluid or liquid food product
sensitive to light radiation according to the present invention is globally indicated
with 1.
[0042] Packaging 1 essentially comprises a container 2 of plastic material, substantially
bottle-like shaped having a vertical X-X axis, a side wall 3 extending between a mouth
4 closed by a respective cap 5 and a bottom 6, and a film 7 of plastic material externally
tied to this side wall 3.
[0043] According to a first characteristic of the present invention, this film 7 of plastic
material is a metallized film.
[0044] The expression metallized film is here used to indicate a film of plastic material
whereon, on the side facing the side wall 3 of the container 2, a reduced amount of
a powder of a metal is deposited to form a metal layer with a thickness of a few hundredths
of micron, not excluding however the possibility of providing such a layer on the
other side or on both sides of the film.
[0045] This metal layer is a layer sufficient to make the film opaque to light radiation
and it is preferably an aluminium layer having a thickness comprised between 10 nm
and 20 nm, more preferably 15 nm.
[0046] Further, advantageously, the above metallized film 7 is of the so-called thermoshrinking
type.
[0047] The expression thermoshrinking film means a film which shrinks when it is subjected
to heating.
[0048] According to a further characteristic of the invention, the above container 2 and
the above film 7, in packaging 1, are made of the same plastic material.
[0049] Among the plastic materials which can be used the polyethylene terephthalate or PET
is the preferred one.
[0050] In packaging 1, film 7, externally tied to the side wall 3, extends, along the vertical
direction of the container 2, for a section of prefixed length.
[0051] In particular, the length of said section is only slightly lower than the height
of the container 2.
[0052] As a consequence, the side wall 3 of the container 2 is substantially entirely covered
by the metallized film 7, except from a limited upper end portion 3a, whereon the
film does not extend.
[0053] Cap 5 of packaging 1 covers however this limited upper end portion 3a and it is in
turn covered on bottom by film 7, which thus advantageously constitutes a warranty
seal.
[0054] A packaging 1 for containing long life milk according to a preferred embodiment of
the invention is now described.
[0055] Such a packaging 1 is obtained starting from a pre-mould and from a film made of
the same plastic material, in particular polyethylene terephthalate.
[0056] From the pre-mould, of 29 grams in weight comprising an additive absorbing ultra-violet
radiation, subsequently to blowing, a substantially bottle-like shaped container 2
is obtained comprising a side wall 3 and having a vertical X-X axis.
[0057] From the film of the so-called thermoshrinking type, through a conventional metallization
process, a metallized film 7 is obtained by depositing some aluminium powder on one
side thereof.
[0058] The aluminium layer thus formed on this side has a thickness in the order of the
hundredths of micron and it is selectively deposited on this side of the film, so
that this latter in correspondence of an end portion thereof along the vertical direction
lacks this aluminium or metallization layer.
[0059] The film is thus made in the form of a sleeve through welding along this portion
lacking metallization.
[0060] The above portion, however, in the welding overlaps a metallized portion of the film,
so that a totally metallized sleeve results.
[0061] The sleeve of metallized film is thus put on the container 2, upon filling of this
latter with long life milk and closing thereof with a respective cap 5 of plastic
material.
[0062] In particular, the sleeve of metallized film 7 is put on the container 2 by making
the metallized side face the side wall 3 of the container 2.
[0063] At this point, the metallized film 7 and the container 2 are subjected to thermal
treatment through heating in a steam oven.
[0064] During the above thermal treatment film 7 is tightly merged in the container 2.
[0065] In particular, further to heating, the thermoshrinking film 7 undergoes a shrinking
or contraction in size; at the end of the thermal treatment it tightly adheres to
the side wall 3 of the container 2.
[0066] In order to evaluate if the packaging according to the present invention guarantees
a correct preservation of the food product contained therein, several comparative
tests have been carried out.
[0067] These tests have been carried out on the same food product: UHT milk, packaged and
contained in packages according to the present invention and respectively in packages
of Tetra Pak® of equal capacity equal to 1 litre.
[0068] The tests have been carried out on the examined samples for periods of time of preservation
of 15, 30, 45, 60, 75, 90 and 105 days on packages conditioned at the temperature
of 23°C.
[0069] In the analyses carried out through the tests the content of the following vitamins
has been determined:
Vitamin A
Vitamin E
Vitamin B1
Vitamin B2
Vitamin B3
Vitamin B5
and of the following proteins:
Alpha Casein
Beta Casein
Kappa Casein
Beta Lactoglobulin
Alpha Lactoglobulin + AY53
Peptide A
[0070] The comparative results of the values found in the preservation test are reported
in the herebelow tables, wherein the reference acronyms PETm and Brik indicate a packaging
according to the present invention and respectively a Tetra Pak® packaging.
[0071] From the tables it is evinced that, for all the examined aspects, no meaningful differences
have been found.
Vitamin A (µg/ 100g) |
15 gg |
30 gg |
45 gg |
60 gg |
75 gg |
90 gg |
105 gg |
PETm |
45 |
64 |
59 |
48 |
48 |
65 |
69 |
BRIK |
45 |
63 |
57 |
55 |
57 |
47 |
52 |
Vitamin E (mg/100g) |
15 gg |
30 gg |
45 gg |
60 gg |
75 gg |
90 gg |
105 gg |
PETm |
0.059 |
0.062 |
0.060 |
0.053 |
0.056 |
0.065 |
0.055 |
BRIK |
0.054 |
0.067 |
0.055 |
0.069 |
0.062 |
0.044 |
0.052 |
Vitamin B1 (mg/100g) |
15 gg |
30 gg |
45 gg |
60 gg |
75 gg |
90 gg |
105 gg |
PETm |
0.04 |
0.04 |
0.04 |
0.04 |
0.04 |
0.04 |
0.02 |
BRIK |
0.04 |
0.04 |
0.04 |
0.04 |
0.03 |
0.04 |
0.02 |
Vitamin B2 (mg/100g) |
15 gg |
30 gg |
45 gg |
60 gg |
75 gg |
90 gg |
105 gg |
PETm |
0.16 |
0.16 |
0.16 |
0.15 |
0.15 |
0.17 |
0.19 |
BRIK |
0.17 |
0.15 |
0.17 |
0.16 |
0.15 |
0.18 |
0.16 |
Vitamin B3 (mg/100g) |
15 gg |
30 gg |
45 gg |
60 gg |
75 gg |
90 gg |
105 gg |
PETm |
0.096 |
0.13 |
0.14 |
0.12 |
0.16 |
0.13 |
0.15 |
BRIK |
0.10 |
0.13 |
0.14 |
0.12 |
0.14 |
0.14 |
0.16 |
Vitamin B5 (mg/100g) |
15 gg |
30 gg |
45 gg |
60 gg |
75 gg |
90 gg |
105 gg |
PETm |
0.32 |
0.38 |
0.34 |
0.28 |
0.40 |
0.44 |
0.39 |
BRIK |
0.35 |
0.39 |
0.32 |
0.45 |
0.40 |
0.45 |
0.40 |
Alpha Casein % |
15 gg |
30 gg |
45 gg |
60 gg |
75 gg |
90 gg |
105 gg |
PETm |
35 |
35 |
37 |
35 |
36 |
36 |
36 |
BRIK |
35 |
35 |
35 |
34 |
34 |
34 |
34 |
Beta Casein % |
15 gg |
30 gg |
45 gg |
60 gg |
75 gg |
90 gg |
105 gg |
PETm |
22 |
22 |
21 |
23 |
22 |
21 |
22 |
BRIK |
23 |
21 |
22 |
20 |
21 |
18 |
20 |
Kappa Casein % |
15 gg |
30 gg |
45 gg |
60 gg |
75 gg |
90 gg |
105 gg |
PETm |
12 |
13 |
13 |
13 |
13 |
13 |
13 |
BRIK |
13 |
14 |
12 |
14 |
13 |
15 |
14 |
Beta Lactoglobulin % |
15 gg |
30 gg |
45 gg |
60 gg |
75 gg |
90 gg |
105 gg |
PETm |
21 |
20 |
21 |
20 |
20 |
21 |
20 |
BRIK |
18 |
19 |
18 |
20 |
20 |
19 |
20 |
Alpha Lactoglobulin + AY53 % |
15 gg |
30 gg |
45 gg |
60 gg |
75 gg |
90 gg |
105 gg |
PETm |
8 |
7 |
8 |
8 |
8 |
8 |
8 |
BRIK |
8 |
9 |
8 |
9 |
8 |
9 |
8 |
Peptide % |
15 gg |
30 gg |
45 gg |
60 gg |
75 gg |
90 gg |
105 gg |
PETm |
2 |
3 |
2 |
2 |
3 |
3 |
3 |
BRIK |
2 |
2 |
3 |
2 |
2 |
3 |
2 |
[0072] The main advantage of the packaging according to the present invention stays in the
combined achievement of a high protection from light radiation and a high resistance
to the passage of oxygen.
[0073] In this way, a correct preservation and a prolonged shelf life is guaranteed for
the food product contained in the packaging according to the invention.
[0074] Film 7 of plastic material, due to the metal layer on at least one side thereof,
protects the container 2 of packaging 1 and thus the product contained therein from
light radiation capable of causing undesired degradation reactions, especially degradation
of the vitamins and proteins in the food product.
[0075] The container 2 of plastic material, in particular PET, guarantees a high resistance
to the passage of oxygen, having good barrier properties with respect to gas.
[0076] Moreover, the manufacture of the container 2 and of the film 7 with the same plastic
material is particularly advantageous both from the economical and ecological point
of view.
[0077] And further, given the extremely limited thickness of the metallization on film 7,
the entire packaging 1 can be considered as realised with a single material, the amount
of metal contained therein being negligible.
[0078] This aspect makes it more efficient the recuperation and reuse of the recyclable
material in the packaging.
[0079] In this regard, it is useful to underline how the use of polyethylene terephthalate
for realising the container 2 and the film 7 makes the packaging according to the
present invention totally recyclable.
[0080] Polyethylene terephthalate, in fact, is a thermoplastic polyester easily reusable
which can be employed both in the manufacture of bottles and various containers and
in a different field such as for example in the field of fibres to realise fabrics,
packages and similar products.
[0081] It is also to be said that the use of polyethylene terephthalate is economically
advantageous since its cost is very competitive with respect to other materials used
in similar applications.
[0082] Further, polyethylene terephthalate easily allows to realise manufactures of good
quality, i.e. packages well defined by well arranged details.
[0083] This latter aspect has a positive influence both on the functionality of packaging
1 - e.g. it allows the realisation of an effective coupling between the cap 5 and
the container 2 - and on the aesthetic aspect of packaging 1 making it particularly
pleasant.
[0084] Obviously, a skilled in the art will be allowed to apply several modifications and
variations to the above described invention.
[0085] For example packaging 1 can comprise, in order to entirely cover the bottom of the
container 2, a lid of plastic material opaque to light radiation associated with the
above bottom 6 of the container 2, for example by fitting it thereon.
[0086] Preferably, the above lid of plastic material can be provided peripherally equipped
with an edge projecting on top covering a lower end portion of the side wall 3 of
the container 2.
[0087] A skilled in the art, in order to meet specific, contingent needs, will be allowed
to add other variations and modifications to those of the packaging according to the
present invention, all within the scope of protection of the invention as defined
in the following claims.
1. A packaging (1) for fluid or liquid food products sensitive to light radiation comprising
a container (2) of plastic material including a bottom (6), a side wall (3), a mouth
(4), a cap (5) closing said mouth (4) and a film (7) of plastic material, said film
(7) being externally tied to the side wall (3) of said container (2), characterised in that said film (7) is metallized on at least one side thereof.
2. A packaging according to claim 1, wherein said film (7) of plastic material is thermoshrinking.
3. A packaging according to claim 1 or 2, wherein said film (7) of plastic material is
metallized on one side only, said side facing the side wall (3) of said container
(2).
4. A packaging according to any claim 1 to 3, wherein said container (2) and said film
(7) are made of the same plastic material.
5. A packaging according to claim 4, wherein said plastic material is polyethylene terephthalate.
6. A packaging according to any claim 3 to 5, wherein said metallized film (7) of plastic
material comprises an aluminium layer.
7. A packaging according to claim 6, wherein said aluminium layer has a thickness comprised
between 10 nm and 20 nm, preferably a thickness of 15 nm.
8. A packaging according to any of the preceding claims, wherein said metallized film
(7) substantially covers said side wall (3) entirely and optionally at least one portion
of said closing cap (5) and at least one portion of said bottom (6) of the container
(2).
9. A packaging according to any of the preceding claims, further comprising a lid of
plastic material opaque to light radiation associated with the bottom (6) of the container
(2), said lid being peripherally equipped with an edge projecting on top for covering
a lower end portion of said side wall (3) of the container (2).
10. Use of a film (7) of plastic material metallized on at least one side thereof to coat
a container (2) for a fluid or liquid food product sensitive to light radiation.
11. Use according to claim 10, wherein said food product is milk.
12. A method for obtaining a packaging (1) for a fluid or liquid product sensitive to
light radiation, comprising the application of a film (7) of plastic material metallized
on at least one side thereof on a side wall (3) of a container (2) filled in with
said product.
13. A method according to claim 12, wherein said film (7) is thermoshrinking, it is made
in the form of a sleeve and it is applied by putting said sleeve on said container
(2) and by subsequently inducing the shrinking of the sleeve further to exposure to
heat.
Amended claims in accordance with Rule 86(2) EPC.
1. A packaging (1) for fluid or liquid food products sensitive to light radiation comprising
a container (2) of plastic material including a bottom (6), a side wall (3), a mouth
(4), a cap (5) closing said mouth (4) and a film (7) of plastic material, said film
(7) being externally tied to the side wall (3) of said container (2) by its being
thermoshrunk onto the container (2), characterised in that said container (2) is made of polyethylene terephthalate (PET) and in that said film (7) is metallized on at least one side thereof.
2. A packaging according to claim 1 , wherein said film (7) is metallized on one side
only, said side facing the side wall (3) of said container (2).
3. A packaging according to claim 1 or 2, wherein said plastic material of said film
(7) is polyethylene terephthalate.
4. A packaging according to any claim 1 to 3, wherein said metallized film (7) of plastic
material comprises an aluminium layer.
5. A packaging according to claim 4, wherein said aluminium layer has a thickness comprised
between 10 nm and 20 nm.
6. A packaging according to any of the preceding claims, wherein said film (7) substantially
covers said side wall (3) entirely and optionally at least one portion of said closing
cap (5) and at least one portion of said bottom (6) of the container (2).
7. A packaging according to any of the preceding claims, further comprising a lid of
plastic material opaque to light radiation associated with the bottom (6) of the container
(2), said lid being peripherally equipped with an edge projecting on top for covering
a lower end portion of said side wall (3) of the container (2).
8. A Packaging according to any of preceding claims, wherein the polyethylene terephthalate
which said container (2) is made of comprises an ultra-violet radiation-absorbing
additive.
9. Use of a thermoshrinking film (7) of plastic material metallized on at least one
side thereof, to coat a container (2) made of polyethylene terephthalate for a fluid
or liquid food product sensitive to light radiation, in order to protect said product
against light radiation, wherein said film (7) is thermoshrunk onto said container
(2).
10. Use according to claim 10, wherein said food product is milk.
11. Use according to claim 10, wherein said food product is UHT milk.
12. A method for obtaining a packaging (1) for a fluid or liquid food product sensitive
to light radiation, comprising the application on a side wall (3) of a container (2)
made of polyethylene terephthalate and filled in with said product of a thermoshrinking
film (7) of plastic material metallized on at least one side thereof, by thermoshrinking
said film (7) onto said container (2) to confer protection to said product against
the light radiation.
13. A method according to claim 12, wherein said film (7) is made in the form of a sleeve
and it is applied by fitting said sleeve onto said container (2) and by subsequently
inducing the shrinking of the sleeve further to exposure to heat.