Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02456709 2004-02-03
-1-
"Sealing wrapper for food products, corresponding
process and installation"
***
The present invention relates to sealed wrappers
(so-called "hermetic" wrappers) for foodstuffs, such as
for example confectionery products.
In the packaging of foodstuffs, it is necessary to
take into account different requirements, first of all
the need to ensure that the product will remain
unaltered for as long a period as possible after
packaging.
In order to achieve the above purpose, for some
time there has been known, also for foodstuffs of small
format (such as chocolates, sweets, pralines, etc.),
is wrapping of the products in sealed wrappers of the type
commonly referred to as "flow-pack". This technique of
wrapping envisages starting from a reel of sheet
material, which is wrapped around the product in the
longitudinal direction by a forming device so as to
form a continuous tubular intermediate piece of
wrapping closed by a first longitudinal sealing line.
The products to be wrapped advance in the tubular
intermediate piece, and the ensemble thus obtained is
subjected to the action of one or more closing
stations. Here, the tubular intermediate piece is
flattened, welded and cut in the areas of separation
between successive products so as to give rise to
individual wrappers. An example of this technique is
described in the document EP-A-O 957 043.
Even if considerations of a functional nature
(linked, for example, to the fact that the regions
where the transverse end welds of the flow-pack
wrapping overlap the longitudinal welding or sealing
line may constitute areas that are critical for the
purposes of the seal) are left aside, the flow-pack
CA 02456709 2004-02-03
-2-
wrapping appears unquestionably as a result of an
industrial process. This wrapping thus proves far from
suitable for use in the case of products (such as
certain confectionery products) to which it is intended
to associate a wrapping of a more traditional type,
such as traditional wrapping for sweets, with the
product contained in a wrapping which has one or both
of its ends twisted to form fantails (fantail twist-
wrapping).
For this reason, there have already been proposed
in the known art solutions that aim at reproducing said
more traditional forms of wrapping.
A solution of this type is described, for example,
in the document WO-A-02/22445: individual lengths of an
intermediate piece of a flow-pack wrapping type,
wrapped around the product so as to form a tubular
structure, undergo squeezing in a radial direction so
as to form areas of crinkling to some extent
reminiscent of the fantail twist-wrapped ends of a
wrapping for sweets of a traditional type.
The main drawback of this type of wrapping lies in
the fact that the action of sealing with respect to the
external environment should be carried out precisely in
the areas subjected to radial compression. Tests show,
however, that, even resorting to a wrapping material
that can undergo at least partial melting in the areas
subjected to radial compression, the degree of
effective sealing with respect to the external
environment is rather modest. This fact is altogether
understandable, given that, in the aforesaid areas, the
wrapping material subjected to compression in a radial
direction tends to form creases in a way that is
altogether uncontrolled. As a result, creases or ridges
are formed having a pattern that is altogether random,
3s between which there may easily remain open, or may open
CA 02456709 2004-02-03
-3-
up after a short period time, paths of communication
with the external environment.
Solutions that enable an excellent degree of
sealing to be obtained with respect to the external
environment are described in the documents EP-A-0 591
742 and EP-A-0 790 184. In both cases, they are,
however, solutions in which a wrapping comprising two
elements of sheet material is used.
The purpose of the present invention is to provide
a wrapping capable of combining, with extreme
structural simplicity, and consequently with extreme
simplicity and economy of fabrication, excellent
sealing qualities (hermetic sealing).
According to the present invention, the above
is purpose is achieved thanks to a wrapping having the
characteristics referred to in the ensuing claims. The
invention also regards the corresponding process of
fabrication, as well as the corresponding plant.
Basically, the solution according to the invention
is characterized in that it gives rise to a wrapping
that comprises a single sheet element closed by a
single welding or sealing line.
For the above purpose, there is provided a sealed
wrapping for foodstuffs, which comprises:
- a wrapping sheet with a bent part or hollow,
which receives at least one foodstuff product; and
- a sealing line which extends so as to close said
wrapping sheet along a path that surrounds said at
least one foodstuff product and has the ends located in
a position corresponding to said bent part.
Evidently, the term "wrapping sheet" is here
understood to indicate any sheet material capable of
isolating the product in an effective way from the
external environment.
CA 02456709 2008-10-06
= -4-
Once again, the term path which "surrounds" the
foodstuff product is here understood to indicate a path
which extends around the product (a path preferably
having a generally arched, i.e., C-shaped pattern),
usually privileging quite a tight relationship of
wrapping, thus guaranteeing a wrapping of the product
that is as adherent as possible, this being a result that
can be favoured by possible actions of smoothing,
brushing or other operations.
According to one aspect of the present invention
there is provided a sealed wrapping for foodstuffs,
comprising: a wrapping sheet with a bent part, which
receives at least one product, and a sealing line, which
extends so as to close said wrapping sheet along a path
that surrounds said at least one product and has the ends
located in a position corresponding to said bent part,
wherein said sheet of wrapping comprises two lateral
branches, which extend from said bent part on opposite
sides of said at least one product, said sealing line
extending so that it connects said lateral branches,
characterized in that it moreover comprises at least one
end part having a fantail conformation.
According to a further aspect of the present there
is provided the process for sealed wrapping of
foodstuffs, comprising the operations of: forming a
wrapping sheet with a bent part, setting said at least
one product in said bent part, and forming a sealing
line, which extends so as to close said wrapping sheet
along a path that surrounds said at least one product and
has the ends located in a position corresponding to said
bent part, comprises the operations of: forming in said
sheet of wrapping two lateral branches which extend from
CA 02456709 2008-10-06
-4a-
said bent part on opposite sides of said at least one
foodstuff product, and forming said sealing line so that
it connects said lateral branches.
According to another aspect of the present invention
there is provided a plant for sealed wrapping of
foodstuffs, comprising: a forming device for forming a
wrapping sheet with a bent part; a loading station for
setting said at least one foodstuff product in said bent
part; and a sealing station configured for forming a
sealing line, which extends so as to close said wrapping
sheet along a path that surrounds said at least one
foodstuff product and has the ends located in a position
corresponding to said bent part, wherein said forming
device is configured for forming, in said sheet of
wrapping, two lateral branches, which extend from said
bent part on opposite sides of said at least one
foodstuff product, and in that said sealing station is
configured for forming said sealing line so that it
connects said lateral branches, characterized in that it
comprises a shaping station for forming, in said
wrapping, at least one end part having a fantail
conformation.
The invention will now be described, purely by way
of non-limiting example, with reference to the annexed
drawings, in which:
Figures 1 to 5 illustrate successive steps of a
process designed to provide a wrapping according to the
invention; and
Figure 6 is a side elevation of the corresponding
plant.
The exemplary embodiment illustrated in what follows
relates to the production of a wrapping for a foodstuff
product 1 consisting, for example, of a confectionery
CA 02456709 2008-10-06
-4b-
product, such as a chocolate, a sweet, a praline, etc. of
various shapes.
In particular, this may be a product provided with a
coating, such as for example a coating of ground
hazelnuts, grated coconut, grated meringues, etc.
In any case, neither the dimensions, nor the shape,
nor again the nature and/or specific characteristics of
the product (single or composite) constitute an element
of limitation of the present invention.
The product 1 is designed to be wrapped in a
wrapping constituted by a single sheet element 2 of a
laminar wrapping material of the type widely used for the
wrapping of confectionery products.
CA 02456709 2004-02-03
-5-
This is consequently a sheet material capable of
isolating the product effectively from the external
environment. It may be, for example, a sheet of
aluminium foil and/or plastic material. The material in
question may be a "combined" material, i.e., a material
which comprises at least one first layer, designed to
constitute the outer part in the finished wrapping, and
a second layer, designed to constitute the inner part
in the finished wrapping, and which presents, for
example, characteristics of heat-sealability.
A typical example of combined material of this
nature is a material consisting of an outer foil made
of aluminium coated on the internal surface with a
plastic material, such as polyethylene.
is It will be appreciated in any case that the
solution described herein is not in any way limited to
a particular choice of the sheet wrapping material, nor
to the adoption of particular technical procedures of
closing/sealing of the wrapping material itself.
In the exemplary embodiment illustrated herein
(which, it is once again emphasized, is purely an
example), it is assumed that the process starts from an
element of sheet material 2 having, for example, the
form of a square or approximately square sheet with a
side of a few centimetres in length.
As will emerge more clearly from what follows, the
said individual element of wrapping may in fact be
defined by a portion or length of a continuous sheet
material, which is reeled off a reel and subjected to
segmentation so as to form individual elements of
wrapping.
On the element of wrapping 2 represented by Figure
1 there is then laid, in an approximately central
position, the product or article 1 to be wrapped.
CA 02456709 2004-02-03
-6-
In the drawings, the said product is represented
in the form of a body having a parallelepipedal shape;
however, it will be understood that the product 1 may
be of any shape.
In a further step of the process of formation of
the wrapping, the element of sheet material 2 is
wrapped around the product 1 so as to form:
- a bent part 20, which in effect receives within
it the product 1; and
- two lateral branches 21, which extend from the
bent part 20 and are laid on the opposite faces of the
product 1 (top and bottom faces in the orientation
illustrated herein).
From an examination of Figure 3, it may readily be
is appreciated that the sheet of wrapping is wrapped
around the product 1 in such a way as to form a sort of
pocket or envelope in which the lateral branches 21
conserve a substantially plane orientation, whatever
the shape of the product 1.
In practice, the two lateral branches 21 are
substantially parallel to one another, separated by a
distance substantially corresponding to the thickness
or height of the product 1.
In yet a further subsequent step of the process,
as is represented in Figure 4, the two lateral branches
21 are connected to one another by a sealing line 3.
The sealing line 3 connects the two branches of
the sheet of wrapping according to a path that
surrounds the foodstuff product 1. It is therefore in
general a path having an overall arched, i.e., C-shaped
pattern, with the ends located in a position
corresponding to the bent part 20, the said bent part
evidently already performing an action of sealed
reception of the product 1, without any need to form
lines of connection.
CA 02456709 2004-02-03
-7-
In order to form the sealing line 3 it is possible
to resort to a wide variety of techniques extensively
adopted in the packaging industry, in particular for
the packaging of foodstuffs.
s Consequently, the sealing line 3 may be made - for
example - by means of hot-sealing, cold-sealing,
sealing with or without weld material, ultrasound
welding, laser welding or, possibly, by means of a mere
action of embossing.
As regards the path of the sealing line 3, albeit
preserving the general enveloping pattern in regard to
the product 1, it is possible to adopt different
choices.
The tests currently conducted by the present
applicant indicate as preferential the choice of a path
with a substantially continuous arched pattern,
consequently without any cusps andJor any overlapping
of ridges or creases of wrapping material (i.e.,
without the overlapping of more than two layers of
wrapping material)- Areas of this type could result,
for example, from the connection of two contiguous
rectilinear stretches and could lie at the basis of
phenomena of concentration of states of coercion that
might weaken the seal of the sealing line.
As further finishing operation, the wrapping
presented in Figure 4 may be completed by forming one
or two fantail twist-wrapped parts 4 so as to bestow on
the wrapping as a whole the typical appearance of a
wrapping for sweets. This result may be obtained (in a
known way) by subjecting to twisting the longitudinal
end or ends of the wrapping, or else resorting to other
methodologies aimed at obtaining a fantail twist.
It will be appreciated that the possible formation
of said fantail twist-wrapped parts (which - it is once
again emphasized - does not represent an imperative
CA 02456709 2004-02-03
-8-
characteristic of the solution described herein) does
not adversely affect the characteristics of sealing of
the sealing line 3. This is, in fact, obtained by
connecting the two lateral branches 21 of the sheet
s wrapping material 2 whilst these are kept in a
condition of substantial planarity.
The connection between the two branches 21 is
therefore extremely intimate and continuous, and
consequently such as to withstand, without weakening,
any possible subsequent deformations of the wrapping.
Now passing to an examination of the diagram of
the plant of Figure 6, the reference number 10
designates a unreeling assembly from which is reeled
off the sheet material that is to constitute the
wrapping 2.
Starting from the unreeling device 10 (which is of
a known type), the sheet material 2 is fed towards a
forming assembly 12 designed to bestow on the sheet
material the general U-like shape comprising the bent
part 20 and the lateral branches 21 (see Figure 3).
Also the forming device 12 may be considered in
itself as an element of a known type. It is in fact
obtainable according to the criteria widely used for
making forming devices which, in packaging machines of
a flow-pack type, close the sheet material according to
a general tubular pattern.
Whilst the tubular wrapping formed in flow-pack
machines (or in the solution described in WO-A-
02/22445) is characterized typically in that it is
closed by a longitudinal sealing line and in that it
has a substantially circular cross-sectional profile,
the corresponding intermediate piece obtained in the
plant of Figure 6 is instead open (see once again
Figure 3) , in the sense that the two lateral branches
CA 02456709 2004-02-03
-9-
21 are not connected to one another in a position
corresponding to their distal margins.
Once again, the intermediate piece represented by
Figure 3 presents a general U-shaped development, with
the two lateral branches 21 maintained in a
substantially flattened condition. As has already been
said previously, this fact is important for achieving a
continuous and intimate connection, provided by means
of the sealing line 3, which lies at the base of the
io characteristics of sealing of the final wrapping.
Feed of the products 1 to be wrapped in the
direction of the area where the forming device 12
operates is ensured by a conveyor 14 consisting, for
example, of a motor-driven belt conveyor of the type
widely used in plants for packaging foodstuffs.
The said conveyor 14 co-operates with the forming
device 12 so as to cause the products 1 to be inserted
in the wrapping material folded to form a U shape at
regular distances apart, thus creating a loading
station designated as a whole by 16.
Fed, in said conditions, by a further conveyor (of
which usually the intermediate piece of wrapping
material constitutes an active element, since it
transports with it the products 1 located therein), the
products are carried into a position corresponding to a
closing station 18, which makes the sealing line 3 and
segments the ribbon of wrapping material in the areas
left free by the products so as to give rise to
distinct wrappers.
According to a structure in itself known, the
closing station 18 may be of the type with vertical
reciprocating movement and thus comprise a base or
anvil part 18a, as well as an active mobile element
18b, which moves vertically and is lowered periodically
onto the anvil part 18a, thus creating the sealing line
CA 02456709 2004-02-03
-10-
3 and carrying out cutting of the individual wrappers.
For the above purpose, the base part 18a and/or the
active element 18b usually present surface indentations
that define the path of the sealing line 3. The base
part 18a and/or the active element 18b may have
associated thereto heating elements and/or ultrasound
generators (not specifically illustrated but of a known
type) when the sealing technology adopted involves the
application of heat and/or ultrasound.
io Advantageously (and also here according to
criteria in themselves known), the closing station 18
may be built so as to carry out, in addition to the
vertical movement that leads the base part 18a and the
active element 18b to close against one another with
is the interposition of the wrappers, also a movement of
"tracking" of the advance of the wrappers. The said
tracking movement causes the action of formation of the
sealing line 3 to come about in conditions of
practically no relative movement.
20 The fixed anvil part 18a may present a top
surface that is at least slightly hollowed so as to
ensure that the sealing line 3 (made with the wrapping
comprised between the parts 18a and 18b closed against
one another) will be obtainable in conditions of
25 perfect symmetry.
Usually, the sealing unit 18 carries associated
thereto cutting elements (not specifically illustrated,
but of a known type) aimed at causing the continuous
ribbon of sheet material 2 to be divided after or
30 concomitantly with the formation of the sealing line 3
so as to give rise to individual wrappers, such as the
wrapping designated by C in Figure 6.
The reference number 20 designates a shaping
station, in which one or both of the longitudinal ends
35 of the wrapping C are subjected to a further treatment
CA 02456709 2004-02-03
-11-
(for example twisting) so as to form the fantail parts
4 of Figure S.
The wrappers thus completed are gathered in a
gathering station 22 in view of the subsequent further
packaging.
As has already been said previously, the formation
of one or more fantail parts 4 constitutes an optional
and non-imperative step of the solution described
herein.
It will therefore be understood that, without
prejudice to the principle of the invention, the
details of implementation and the embodiments may vary,
even to a major extent, with respect to what is
described and illustrated purely by way of non-limiting
example, without departing from the scope of the
invention, as defined by the claims that follow.
