Note: Descriptions are shown in the official language in which they were submitted.
21123~~.
nL'C!'T.7 T D~f'TnTT
The present invention relates to a method and a device
for ,~~apping a product in a wrapper of sheet material.
T.he invention has been developed with particular
a+-tention to its possible use fer packaging products
such as, for example, food products, particularly
confectionery. In this field of application, the
products (for example, spherical pralines, hollow or
filled chocolate eggs, etc.) are quite often wrapped in
sheets of material such as, for example, aluminium.
For example, European patent EP-B-0 082 952 describes a
method which enables an approximately spherical praline
to be wrapped in a sheet of aluminium. For this
purpose, the product, placed on a sheet of aluminium,
is passed through a structure with resilient blades so
that after the sheet has assumed a generally cup-like
configuration, as a result of being wrapped around the
product, it is closed behind the product like a bunch
or tail when the latter emerges from the resilient
formations. The bunch or tail thus formed is then
upset onto the product so that the product is
completely wrapped in the sheet.
A solution which achieves the same final effect by a
slightly different method is described in German patent
DE-A-32 43 500.
The solutions described in the prior documents
mentioned above produce excellent results, particularly
as regards the appearance of the final product
obtained. This is usually intended to be inserted in
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2
a paper cup with pleated walls with the portion of the
wrapper which is upset onto the product facing
downwardly, resting on the base of the cup. The upper
part of the product is thus protected by a sheet
wrapped neatly around the product.
The Applicant has found that these previously known
solutions could be further improved, particularly as
regards isolation from the outside atmosphere.
From this point of view, it is generally known (see,
for example, German utility model DE 1784647U) to
package food products (such as chocolate or sugar-based
products) in close-fitting wrappers of sheet material,
such as aluminium, which are produced by forming two
complementary aluminium leaves, each of which closely
copies the shape of a respective half of the product.
The two leaves of sheet wrapper thus produced are then
interconnected along an equatorial line of the product,
for example, by heat sealing, making use of the
presence of a coating of hot-melting material on the
mutually coupled faces, with the removal of the
remaining parts of aluminium sheet which project beyond
the region of the seal.
This solution, however, is unsuitable for use in a
field such as that described above, particularly when
the wrapped product is to be inserted in a paper cup.
In fact the seal along the equatorial line is visible,
giving the product as a whole an appearance typical of
an automatically-packaged industrial product. On the
other hand, it is desirable, particularly in the
confectionery field, for the industrial product to
retain presentation characteristics typical of a
hand-made or semi-hand-made product and hence not to
CA 02112301 2005-06-30
3
display seal lines, which are signs of the intervention
of a machine, in visible positions.
The object of the present invention is to provide a
packaging solution which retains the advantages of the
solutions described above in combination, but which
eliminates the disadvantages just considered.
According to the present invention, this object is
achieved by virtue of a method which includes the steps
of (i) providing first and second sheets of wrapping
material, (ii) shaping the first sheet to form a shape
substantially complementary to that of the product to be
wrapped such that once the first sheet if shaped, it
covers a greater part of the product, (iii) inserting
the product into the first shaped sheet, (iv) applying
the second sheet to the portion of the product left
uncovered by the first sheet so that the second sheet
assumes a shape complementary to the uncovered portion
of the product, (v) joining the first and second sheets
together to form a substantially closed wrapper around
the product, and (vi) further shaping the first sheet
around the product so that the first sheet substantially
hides the second sheet from the exterior.
The invention also relates to a device for carrying out
said method ,
The invention will now be described, purely by way of
non-limiting example, with reference to the appended
drawings, in which:
CA 02112301 2005-06-30
3a
Figures 1 to 6 show successive steps of the method
according to the invention, and
Figure 7 shows the final result of the packaging
operation comprising the steps shown in Figures 1 to 6.
In the embodiment illustrated, the product to be
packaged is constituted by a generally spherical
praline P. For example, this may be a praline
constituted by a spherical wafer shell with a pasty or
creamy filling coated externally with chocolate, for
example hazelnut chocolate, or a similar coating,
211~'~fl~.
possibly with the application of grated coconut,
chopped hazelnuts, etc. which give the outer surface of
the praline P a generally irregular appearance.
It should, however, be underlined that the invention
may be applied to products of different kinds and
completely different shapes. Still within the field of
the confectionery industry, reference may be made to
hollow or filled chocolate eggs, various chocolates,
approximately spherical pralines with flat bottoms,
small meringues, etc.
According to the invention, two small sheets, indicated
1 and 2, of aluminium or other laminar material are
used to form a close-fitting, sealed wrapper around the
product P.
The selection of an aluminium sheet is considered
preferable because it can be fitted around the product
easily and also because the product may have surface
irregularities. In particular, the internal faces of
the two sheets 1 and 2 which are intended to face
towards the product P, are preferably coated with a
lacquer or a layer of hot-melting material. This is
for reasons which will become clearer from the
following.
Moreover, the two wrapping sheets 1, 2 do not generally
have the same dimensions. In fact, the first sheet,
indicated 1, usually has dimensions much larger than
the development in a plane of the facing half portion
(a hemispherical cap-like portion in the present case)
of the product P. By way of indication, the sheet 1,
which is usually square or rectangular, may be
considered to have dimensions approximately sufficient
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_ 5
to cover the product P completely, at most leaving the
polar portion opposite the sheet 1 itself uncovered.
For the piece 2, on the other hand, it is possible to
select dimensions such that its size corresponds
approximately to, or is even slightly smaller than, the
development in a plane of the facing half-portion of
the product P; with reference to the example
illustrated, this half-portion is also defined by a
hemispherical cap-like portion.
The two half-portions mentioned above may be regarded
as being separated by a theoretical equatorial plane Pe
which identifies the maximum cross-section of the
product P; this applies whether the product P is
spherical, as in the embodiment illustrated (a
spherical praline P) or whether it is of a different
shape such as, for example, an egg-shape or a shape
reproducing the features of a small figure. Whatever
the shape of the product P, an equatorial plane Pe
which defines its region of maximum cross-section will
generally be identifiable; in this connection, it can
also be noted that, regardless of their nature,
confectionery products are often themselves constituted
by two complementary portions (hollow or filled)
connected along an equatorial plane Pe.
The first step in the packaging of the product P
consists of a step in which the sheet 1 is shaped
(possibly by drawing) to a generally dished or cup-like
shape. This step is usually carried out by means of a
tool comprising a die 3 defining a cavity 3a which a
punch 4 can enter. For a general description of the
possible criteria for the production of such a shaping
tool, reference may usefully be made to application
DE-A-32 43 500 already mentioned above. The cavity 3a
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6
and the active portion of the tool 4 have complementary
surfaces for shaping the sheet 1 by gripping it between
them. In particular, the lower portion (with
reference to Figure 2) of the cavity 3a in the die 2
has a shape exactly complementary to the shape of the
half-portion of the product P which is to be wrapped by
the sheet 1.
The cavity 3a, however, (and correspondingly, the
drawing tool 4) is generally "deeper" than would be
necessary simply to shape the sheet 1 in a manner
exactly complementary to the respective half-portion of
the product P. This is shown in Figure 2, which shows
the position of the imaginary equatorial plane Pe of
the product P in relation to the cavity 3a. As can be
seen, this equatorial plane Pe is not exactly aligned
with the plane of the mouth of the cavity 3a; on the
contrary, the plane Pe is disposed further within the
die 3 by a distance generally indicated d in Figure 2.
By way of indication, the magnitude of the distance d
may be, for example, of the order of 8-10 mm, in the
case of a spherical product P with a diameter of the
order of about 25-30 mm.
The effect of the shape adopted for the cavity 3a and
the punch 4 is to make the sheet of aluminium 1
generally pot- or cup-shaped so that it can house the
product P as shown schematically in Figure 3. In this
figure, it is assumed that the product P is introduced
into the cup-shaped sheet 1 when the latter is still in
the drawing die 3. Naturally, this selection should
not be considered essential in the sense that, after it
has been made cup-shaped, the sheet 1 may be removed
from the die 3 and transferred to another die or to
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another cavity formation for supporting the sheet 1 for
the insertion of the product P.
Whatever selection is adopted, it will be noted that,
once the product P has been introduced into the
cup-shaped sheet 1, it is wrapped closely thereby, well
above the diametral plane Pe.
In other words, once the sheet 1 has been shaped, in
addition to a hemispherical base portion which is
intended to house the hemispherical lower cap-like
portion of the product P, it also comprises a neck
portion, indicated la, which extends to cover -
although not to fit closely - the opposite (upper)
hemispherical cap-like portion of the product P.
Naturally, it should be noted once more that the
reference to hemispherical cap-like portions is
dictated by the fact that the example of use described
relates to a product P constituted by a substantially
spherical praline. The same considerations apply in
an identical manner, however, if egg-shaped, eliptical
or mixtilinear cap-like portions are concerned rather
than spherical cap-like portions.
By way of orientation, the sheet 1 may be said to cover
between about 2/3 and 3/4 of the length of the product
P, with reference to the "vertical" axis of the product
P, this term meaning an axis perpendicular to the
equatorial plane Pe.
In these conditions (that is, in the condition shown in
Figure 3) the other sheet 2 is then applied to the
product P.
In general, the sheet 2 is simply placed on the upper
2~.1~'3~~
portion of the product P which projects upwards
slightly out of and above the mouth portion of the
cavity 3a.
Since the portion of the product P which projects from
the mouth 3a is small (being of limited "vertical"
height), the sheet 2 can remain, at least
approximately, in the desired position without having
to be formed beforehand so ws to assume a shape exactly
complementary to that of the portion of the product P
which projects from the cavity 3a.
Instead, the sheet 2 is shaped only during a subsequent
step, that is, when the sheets 1 and 2 are brought to
positions in which they fit closely together along the
outline of the mouth portion of the cavity 3a, and are
joined by the operation of a tool 6 (and possibly also
trimmed) .
In this connection, it should be noted that, although
Figure 4 shows a single tool 6, the two steps described
above (joining and trimming) may also be carried out in
two successive steps with the use of two different
tools.
The joining of the two sheets 1 and 2 is intended to
ensure that the sheet wrapper formed around the product
P a.s sealed from the exterior, thus preventing the
product from coming into contact with the air and
possibly deteriorating. The join may be formed with
the use of a purely mechanical connection (for example,
by folding locally), by gluing with applied material,
or even (according to a greatly preferred solution) by
heat-sealing preferably by melting the hot-melting
coatings on the internal faces of the sheets 1 and 2
211~~~~
(by the direct application of heat or by the
application of ultrasound vibration fields).
This can be achieved, for example, by means of a
heat-sealing tool of the type currently used, for
example, for applying sheets of aluminium coated with
hot-melting material to the mouth portions of
cup-shaped containers containing liquid or pasty
products (for example, yoghurts or similar products).
The edges which have been joined together can be
trimmed with a hollow punching tool, the cutting edge
of which, indicated 6a in Figure 4, extends along a
line (a circle in the embodiment illustrated, in which
the product P is spherical) which surrounds the rim of
the mouth portion of the cavity 3a externally.
The trimming tool 6 may advantageously be formed, for
example, as a sonotrode for the application of an
ultrasound front for carrying out the joining
simultaneously with the trimming. Similarly, the
joining may be carried out together with the trimming
by also heating the cutting tool so as to bring about
local fusion of the hot-melting material applied to the
aluminium sheets.
In any case, it can be appreciated that the tool which
first acts on the coupled edges of the sheets l, 2
(typically the welding tool) finishes by simultaneously
also shaping the upper sheet 2 around the cap-like
upper portion of the proudct P which projects from the
cavity 3a. A generally closed and close-fitting
wrapper is thus formed around the product P by a single
positive shaping operation (that is, that carried out
on the sheet 1 during the step shown in Figure 2); the
2~1~30~.
shaping of the sheet 2, however, is not achieved as a
result of a specific shaping operation, but simply
during the joining of the sheet 2 to the sheet 1.
Thus, the solution according to the invention saves one
of the partial shaping operations of the wrapper
conventionally carried out in solutions of the prior
art.
Moreover, the fact that, as far as the wrapping of the
product P by the sheet 1 is concerned, the first sheet
1 is shaped deeply, beyond the equatorial plane Pe,
enables the dimensions of the second sheet 2 to be
reduced considerably thus achieving an overall saving
of wrapping material.
Furthermore, the solution described has also been found
excellent as regards the need to prevent the wrapper,
formed as a result of the joining of the sheets 1 and 2
around the product P, from retaining within it, between
the outer wall of the product P and the inner wall of
the closed wrapper, appreciable masses of air which may
induce a certain deterioration of the product or
possibly bulging of the final package produced.
Upon completion of the joining and the trimming of the
sheets 1 and 2 (Figure 4), the product P, wrapped in
the sheets 1 and 2 which are connected along their
perimetral edges, is introduced into a tool 10
substantially similar to that described in European
patent EP-B-0 082 952. For this purpose, the product
P is removed from the cavity in which it has been kept
for the joining of the sheets 1 and 2 (in the present
description, it is assumed that this cavity corresponds
to the cavity 3a in which the initial shaping of the
sheet 1 was effected, but this selection is certainly
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11
not essential) and introduced into the upper aperture
11 of the tool 10, the sheet 1 being kept facing
downwards.
As described further in the European patent mentioned
above; the tool 10 comprises, essentially, a support
structure in which there is an aperture 11 (which, in
the embodiment illustrated, is assumed to be circular,
with a vertical axis), from which a plurality of
resilient tongues 12, for example of metal, extend
downwards, the tongues being resiliently loaded so
that, in the absence of external forces, they converge
towards the vertical axis of the cavity 11 to generally
congruent positions, in an arrangement comparable to
that of the outer leaves of an artichoke.
The product P, wrapped in the sheets 1 and 2, with the
sheet 1 facing downwards, is passed vertically
downwards through the aperture 11 from above under the
action of a thrust element 13. The resilient tongues
12 spread out as a result of the passage of the product
P and then close again behind the product so that the
sheet 1 is made to fit closely on the half-portion (the
upper half-portion in the position shown in Figure 5)
which was originally opposite the sheet 1. A kind of
tail or bunch is thus formed by the sheet 1 behind the
product P emerging from the tool 10, the sheet 1
enclosing the sheet 2 within it as shown schematically
in chain line in Figure 5.
In particular, as the tongues 12 close resiliently
behind the descending product P (for a detailed
description of the methods and criteria for carrying
out this function, see the description of European
patent EP-B-0 082 952) they close the sheet 1 and the
211301
-- 1 2
sheet 2 within it behind the product P, thus forming a
mass of sheet material which can be upset so as to fit
closely onto the product P, as indicated at 14 in
Figure 6. The upsetting of the mass of sheet material
(formed partly by the sheet 2 which fits closely on the
product P, and partly by the sheet 1 which in turn is
folded onto the sheet 2) is carried out by an upsetting
tool 15 which is mounted around the thrust element 13
for sliding axially and the lower end of which has a
cap-shaped cavity 15a which exactly matches the shape
of the upper portion of the product. For a
description of the criteria which regulate the movement
of the thrust element 13 and of the upsetting tool 15,
reference should again be made to the description of
the European patent already mentioned several times
above.
Upon completion of the upsetting of the sheet wrapper,
the product P may be placed in a paper cup 16 with
pleated walls according to the criteria shown in Figure
7. It will be appreciatd that, in this position, only
the sheet 1 is visible from outside the cup 16. This
sheet does not cover only half of the product P but
covers practically the whole of the product P,
enclosing the sheet 2 within it. The sheet 2,
however, is not visible externally, and neither is the
upset region 14 which is disposed against the base wall
of the cup 16.
Moreover, the seal line along which the sheets 1 and 2
are joined is not visible from the exterior.
The product thus retains the desired final appearance
without seal lines visible from the exterior whilst
being housed in a wrapper which can provide a durable
seal against the outside atmosphere.
