Object of the invention
[0001] The present invention relates to a packaging being of the type of those comprising
a tubular body being formed from a mono- or multilayer sheet and provided at each
of the sides with a respective longitudinally oriented gusset fold for its folding
into a flat arrangement and at the opposite ends with opening and base sealing means,
said tubular body thus delimiting an inner cavity being intended to contain the packaged
product.
Background of the invention
[0002] There exist at present in the market different packagings being made as by way of
sacks or bags and intended to contain different products, said packagings having a
tubular configuration being sealed at the upper and lower ends. These packagings in
a general manner have two opposite larger faces and two also opposite sides, each
of these latter in some cases longitudinally having a respective gusset fold defining
a bellows being intended to allow the empty packaging to be folded into a flat arrangement.
[0003] As for the base sealing means, two clearly different means are generally used.
[0004] In some cases the base is simply sealed by means of a transversal seam being placed
at the centre of the base. These sealing means present several drawbacks from among
which it is worth mentioning that a flat base is not defined in the packaging, this
reducing the stability of the packaging when this latter contains a reduced quantity
of product, and that the weight of the product acts directly on the seam, this latter
being thus subjected to a lateral pressure or stretching favouring the formation of
interstices through which the packaged product leaks especially when being fine such
as for example in the case of meals or ground feeds. Another of the drawbacks of this
central seam is that the base is not continuous but interrupted by the seam, which
prevents the base from being provided with a regular print and deteriorates the product's
appearance when the base of the packaging is in a visible arrangement, such as for
example during the product's storage and display with the packagings stacked in a
lying position.
[0005] In another case and as is also known, the packagings have a flat base being defined
by folding the lateral faces of the packaging towards the central region of the base,
in such a way that they are arranged in an overlapping arrangement. This type of flat
bottom exteriorly incorporates an additional sheet member being stuck as a by way
of patch on the aforementioned overlapping portions, in such a way that they are not
visible from the outside and the outer appearance of the flat base is thus improved.
[0006] These flat bottoms also have some drawbacks from among which can be pointed out the
incorporation of an additional member being supplementary to the actual packaging,
and a bigger manufacturing difficulty due to the sticking operation for the aforementioned
additional member. This sticking creates problems when the additional member and the
sheet making up the packaging are formed of closed-pore materials, these latter being
specially indicated when the packaging has to meet particular requirements, such as
tightness and opacity, since in these cases the glue migrates and is transferred to
the adjacent packagings during the period elapsing from their manufacture up to their
shipment, said packagings during said period remaining in a folded and stacked arrangement
thus causing the packagings to be stuck to each other, which later on hinders their
manipulation during the filling and sealing operations.
[0007] The technical problem to be solved is thus that of developing a packaging being specially
indicated for the packaging of different products and also being resistant and having
a continuous flat bottom so as to thus allow it to be correctly printed and to have
an aesthetically correct appearance, said packaging also being easy to manufacture
and fit to be formed from the very tubular body of the packaging, i.e. without the
incorporation of additional members.
Description of the invention
[0008] The packaging being the object of the invention, being of the type of those comprising
a tubular body being formed from a mono- or multilayer sheet and provided at each
of its sides with a respective longitudinally oriented gusset fold for its folding
into a flat arrangement and with opening and base sealing means, has constructive
particularities being aimed at achieving the targeted objectives as regards the procurement
of a strong sack having a continuous and flat bottom and being easy to manufacture
without the incorporation of additional members.
[0009] For such a purpose and according to the invention the tubular body is inferiorly
provided with a transversal fold being at a distance from its lower end which is sensibly
equal to one-half of the width of the sides of the packaging and in said tubular body
defining a lower portion being arranged in a laid down arrangement on a first larger
face of the packaging and through sealing means having its end fixed to said first
larger face, said lower portion in the spread out position of the packaging and together
with a portion of equal length of the second larger face of the packaging defining
a flat base of rectangular contour wherein the sealing means are arranged at one of
the ends of the aforementioned flat base.
[0010] The arrangement of the sealing means at one of the ends of the flat base determines
that the weight of the product being contained in the packaging in its majority acts
on the transversal fold being defined in the central region of the base rather than
on the sealing means, these latter having been shifted to a side, said arrangement
thus practically totally eliminating the risk of deterioration of the sealing means
due to the action of the product's weight and of product leaks through the packaging
sealing region.
[0011] According to the invention the outer surface of the flat base is formed by a continuous
extension of the second larger face of the packaging, the base thus providing an excellent
aesthetic appearance and forming a surface being fit to allow a correct printing of
the packaging and even of its base.
[0012] In an embodiment of the invention the sealing means establishing the fixing between
the end of the lower portion of the tubular body and the first larger side of the
packaging define at least one sealing line being oriented in a direction being sensibly
parallel to the end of said lower portion and are preferentially defined by sewing,
although other fixing means are not to be discarded such as by welding or gluing,
in each case depending on the type of material forming the packaging.
[0013] With the configuration having been described above, in an embodiment of the invention
the tubular body of the packaging is made up by a multilayer sheet comprising a layer
of woven raffia of polypropylene being laminated with bioriented polypropylene film.
This type of multilayer sheet, in combination with the features relating to the flat
bottom as described above, determine that the obtained packaging besides having a
mechanical strength being adequate for supporting the product's weight is also endowed
with ideally suited moisture and odour insulating and leak preventing properties and
with those allowing to preserve the product being contained in it from the sunlight.
Description of the figures
[0014] To complement the description being given and in order to facilitate the understanding
of the features of the invention the present specification is being accompanied by
a set of drawings wherein with a merely illustrative and nonlimiting character the
following has been shown:
- Figure 1 shows a lateral perspective view from above of an exemplary embodiment of
the packaging of the invention wherein the base fixing and sealing means are represented
by a seam.
- Figure 2 shows a lateral perspective view from below of the packaging of the foregoing
figure wherein the continuity of the second larger face of the packaging on the outside
of the flat base can be observed.
- Figures 3, 4, 5 and 6 each show a profile view of a lower portion of the packaging
and correspond to successive stages of its manufacture in order to facilitate the
identification of the different regions of the packaging which will be alluded to
in the description of said embodiment.
- Figure 7 shows an enlarged detail of a cross-section of the sheet being used in this
exemplary embodiment for forming the packaging.
Preferential embodiment of the invention
[0015] As can be seen in the attached figures the packaging comprises a tubular body (1)
being formed from a multilayer sheet (2) and having: two sensibly equal sides (11)
being each provided with a respective longitudinally oriented gusset fold (12), a
first larger face (13), and a second larger face (14) being opposite to the former
one.
[0016] The tubular body (1) inferiorly has a transversal fold (15) being at a distance from
its lower end which is sensibly equal to one-half of the width of the sides (11),
said transversal fold (15) in the tubular body (1) delimiting a lower portion (16)
being arranged in a laid down arrangement on the first larger face (13) of the packaging,
said end being fixed to said first larger face (13) by sealing means (3) that in the
example being shown are represented by a seam being parallel and next to the aforementioned
end of the lower portion (16) of the tubular body.
[0017] Together with a portion of equal length of the second larger face (14) of the packaging
the lower portion (16) defines a flat and continuous base (17) of rectangular contour
wherein the sealing means (3) are arranged at one of the ends of the aforementioned
flat base (17) and wherein the outer surface of said flat base is made up by an extension
of the second larger face (14) of the packaging and is thus fit to allow its correct
printing.
[0018] As can be seen in figures 1 and 2, the packaging is sealed at its upper end with
sealing means (4) being in this exemplary embodiment represented by a transversal
seam.
[0019] With the above-described configuration the flat base (17) of the packaging can be
easily manufactured, such as can be observed in figures 3 through 6 respectively showing:
- the forming of the transversal fold (15) and the defining in the tubular body of
the end portion (16) having a length being sensibly equal to one-half of the width
of the sides (11),
- the lowering of the end portion (16) onto the first larger face (13) of the tubular
body,
- the spreading out of the packaging, the end portion (16) together with a portion
of equal length of the second larger face (14) defining the flat base (17), and
- the lateral lowering of the tubular body onto the side corresponding to the second
larger face (14) in order to thus facilitate the attachment by sewing of the end of
the end portion (16) of the tubular body to the first larger face (13) of the packaging.
[0020] As can be observed in the detail of figure 7, the multilayer sheet (2) forming the
packaging is made up by a layer of woven raffia (21) of polypropylene forming the
inner surface of the packaging and laminated with a bioriented polypropylene film
(22) forming the outer surface of the packaging.
[0021] Once having sufficiently described the nature of the invention, as well as a preferred
exemplary embodiment, it is now hereby stated to the opportune effects that the materials,
shape, size and arrangement of the elements having been described above will be modifiable
in as much as that doesn't entail an alteration of the essential features of the invention
which are being claimed as follows.
1. A packaging being of the type of those comprising a tubular body (1) being formed
from a sheet (2) and provided at each of the sides (11) with a respective longitudinally
oriented gusset fold (12) for its folding into a flat arrangement and with opening
and base sealing means (3, 4); characterised in that the tubular body (1) is inferiorly provided with a transversal fold (15) being at
a distance from its lower end which is sensibly equal to one-half of the width of
the sides (11) and in said tubular body (1) defining a lower portion (16) being arranged
in a laid down arrangement on a first larger face (13) of the packaging and through
sealing means (3) having its end fixed to said first larger face (13), said lower
portion (16) in the spread out position of the packaging and together with a portion
of equal length of the second larger face (14) of the packaging defining a flat base
(17) of rectangular contour wherein the sealing means (3) are arranged at one of the
ends of the aforementioned flat base (17).
2. A packaging as per claim 1, characterised in that the sealing means (3) establishing the fixing between the end of the lower portion
of the tubular body (1) and the first larger face (13) of the packaging define at
least one sealing line being oriented in a direction being sensibly parallel to the
end of said lower portion (16) and are defined by sewing, welding or gluing.
3. A packaging as per any of the foregoing claims, characterised in that the tubular body (1) is made up by a multilayer sheet (2) comprising a layer of woven
raffia (21) of polypropylene being laminated with bioriented polypropylene film (22).