Note: Descriptions are shown in the official language in which they were submitted.
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Method for producing a sealed package,
Cut blank for the production of the package and
produced package.
The invention relates to a method for producing a
sealed package in accordance with the preamble of claim 1.
It also refers to a cut blank for the production of a sealed
package and a sealed package.
Packages of plastic foils alone have a low loading
capability and, therefore, can hardly be stacked. They can
be easily injured, whereby they get leaky. They are not
suitable for packages which protect the content well.
Relatively sealed packages are the milk packages,
at which the cardboard bearing layer giving the stabili~y
is shielded by projecting joint areas present on the outside
such that the cut edges cannot be softened. The joining
areas of the edges can at best be folded back on the out-
side and form then areas of at least triple material strength,
which form at further connections disturbing bulges and,
therefore, are difficult to seal at those areas. When it
gets hooked at some place, such a joint area can tear and
thus lead to the destruction of the package.
The invention is based on the object to provide
a sealed package by a simple procedure, which, regarding the
material, is advantageous in economic and ecologic respects
and of which the joint areas can be held relatively thin.
In order to solve this object, the method for
producing a sealed package as defined in claim 1 is proposed.
Furthermore, a cut blank for the production of a sealed
package and a sealed package as such æe proposed.
The method in accordance with the preamble of
claim 1 corresponds essentially to the production of milk
packages and specifically has the drawback that either a cut
edge lies freely on the inside of the package and can there
get softened and leaky, or then the cut edges are present
on the outside and represent a disturbing bulge which can
only take part at other joint areas with difficulty.
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With the inventive method the first measures are
taken already when forming the packing material. In the base
layer (eg paper, cardboard and similar, possibly multi-
layered and/or coated) initially a perforation is formed
5 aLdjacent at least one joining edge. Thereafter, a plastic
foil (eg polypropylene etc.) is placed on at least one side
of the base layer in such a manner that the plastic foil
covers also the perforation or perforations, respectively.
Then a cut blank is produced from the packing material thus
10 obtained, at which adjacent at least one joining edge a foil
flap is formed. The material of this foil flap is formed by
a part of the plastic foil which covered the perforation.
During the forming of the joint area the joining edge lo-
cated on the inside of the package and/or on the outer side
15 of the package is sealingly covered by such a foil flap. It
is, therefore, possible to produce a package which is sealed
towards the inside and/or towards the outside. Depending
from the foil, the criteria regarding the sealing properties
can be the same or different.
Thus, a relatively thin and yet sealed joint
area is obtained, at which the sealing foil flap does not
influence the thickness of the joint area.
If it is preferred to use paper- or cardboard-
like materials as the base layer, it is possible to apply
25 besides the reinforcing effect of the fibrous material also
a printing method which is very simple, economical and which
produces aesthetic prints.
In case of plastic foils present at both sides
of the base layer, it is however also possible to let only
30 one of the foils take part on the foil flap belonging to a
joining edge. It is then possible to cover the inner joining
edge by an inner foil flap and the outer joining edge by an
outer foil flap.
If the base layer is enclosed between two plastic
35 foils, it is also possible to let both plastic foils take
part at all foil flaps, such that the base layer is en-
closed along the joining edges already in its cut blank state.
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Very solid joint areas are obtained when the
joining edges are overlapped at their combining to the
joint area. It is not necessary to suffer either thick joint
areas or insufficient sealing properties.
It is also possible to practise the inventive
method in steps which are distant each other, whereby it is
not very important what is made where.
It is possible to produce the packing material as
a roll or sheet, to make the cutting at the final production
10 of the package also during the filling thereof.
It is also possible to transport the produced
cut blanks to the place where the package is produced, for
instance when filling the package.
It is even possible to combine the entire proce-
15 dure with the filling on a production line if such is de-
sired.
For this reason also a packing material and a cut
blank are subject of the invention. The packaging material
is characterized in that it comprises a base layer and at
20 least one plastic foil connected therewith, whereby adjacent
at least one joining edge the plastic foil bridges a perfora-
tion in the base layer with a portion of the foil. This foil
portion forms in the cut blank a freely projecting foil flap.
The base layer is preferably in part like paper
25 or cardboard.
It is, furthermore, also preferred when the base
layer is enclosed between two plastic foils.
The invention will hereafter be discussed exemp-
larily based on the purely schematic illustration of an
30 embodiment.
There is shown in :
Figure 1 a top view onto a part of a packaging
material which comprises as base layer a vertically hatched
cardboard, out of which the perforations have already been
35 punched and onto which a plastic foil is placed at the side
thereof facing the viewer (at the package later inner side)
and which covers also the perforations and being hatched
'
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horizontally,
Figure 2 a top view similar to the one of Fig.l
of a single cut blank produced by a periphery punching,
Figure 3 a small entire view of a package, of
5 which the cylinder jacket has been produced from the cut
blank/ and a dish-shaped bottom and cover, respectively,
is inserted in both its ends,
and
Figure 4 an enlarged section through the joint
10 area of Fig. 3 designed in a superelevated manner.
It shall be noted that the base layer~ and a
plastic foil covering same have the same reference in all
figures.
The following is meant in the drawings :
1 base layer (here a cardboard).
11 perforation in 1, adjacent a future 42 in
Fig. 1 and Fig. 2.
2 plastic foil on the inner side of 1 (in
Fig. 1 above).
21 foil part of 2 over 11 Fig. 1.
3 packing material of 1 and 2.
4 cut blank for cylinder jacket from 3.
41 foil flaps of 4 adjacent 42 ~was in Fig. 1
21 over 11).
42 joining edge adjacent 41 (in Fig. 1 adjacent
11) .
43 joining edge (in Fig. 1 not adjacent perfor-
ation).
44 joint area of 42 and 43.
5 circular cover from 3.
6 package out of one 4 and two 5.
It is possible to print the base layer prior to
the coating by the plastic foil advantageously, simply, at
low cost and aesthetically by a paper printing procedure.
It is possible to firstly coat, laminate, etc.
a base layer part, for example an unprinted or printed paper,
such that in such a case the base layer 1 itself is a multi-
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layered planar article.
It is possible to process the base layer 1 from
a roll or as sheet, whereby the perforations 11 are punched
out by a punching machine. In principle it is possible to
5 proceed in this way adjacent all joining edges 42, 43. In
the illustrated example only one perforation 11 is shown
adjacent each joining edge 42.
The base layer 1 provided with perforations 11
is then joined to a plastic foil 2, whereby the portions 21
10 of the foil cover also the perforations 11.
In principle it is also possible to cover the
other side of the base layer with a plastic foil, which can
specifically be done in such a case when also adjacent the
joining edges 43 perforations (not illustrated here) have
15 been foreseen.
From the base layer 1 and the at least one plastic
foil 2 a packaging material 3 is obtained, from which there-
after cut blanks 4 are produced by peripheral punching. At
the punching the portion 21 of the foil adjacent the joining
20 edge 42 is left there such that a foil flap 41 is produced.
Should perforations and foil portions 21 be pro-
duced also adjacent the joining edges 43, it would be pos-
sible (specifically in the case of a base layer coated on
both sides by a plastic foil) to produce adjacent the join-
25 ing edge 43 a foil flap (not illustrated).
Because here a cylinder-shaped package 6 is sought,
circular covers 5 will be produced which can be simply pun-
ched out of the same combination of base layer and plastic
foil. It is, however, also possible to produce end covers
30 of the cylinder in accordance with other known methods.
In order to produce a cylinder jacket out of the
blank 4, the blank 4 is bent together whereby the plastic
foil is located on the inside. The joining edges 42 and 43
are overlapped and they are joined together for instance
35 by welding to a joint area 44, whereby the foil flap 41
adjacent the joining edge 42 is connected to the plastic
foil (see Fig. 4) in such a manner that the joining edge 42
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is sealingly covered.
At a not illustrated variant, at which also ad-
jacent the foil edge 43 a foil flap would be produced, its
covering would also have to be made in an analogous manner.
In order to complete the package 6, it is now
possible to weld the two circular covers 5 according to
a as such known procedure into the ends of the cylinder.
