Note: Descriptions are shown in the official language in which they were submitted.
CA 02340183 2001-03-09
Packaging with Pull-Open Closure
The invention relates to a flexible packaging made from a packaging film, in
particular a pouch type of packaging with at least one closure seam,
containing a
pull-open closure which exposes an opening for removing the contents. Further,
the invention also relates to a packaging film, a process for manufacturing
the
packaging and the use of the packaging.
Flexible forms of packaging must protect the contents from mechanical,
chemical
and physical influences. For that reason such forms of packaging are in many
cases manufactured from multilayer materials, whereby individual layers of
material or a combination of layers of material may have specific protective
functions attributed to them. The packaging material must e.g. be resistant to
tearing. This makes it necessary to employ materials that are stretchable or
exhibit very high elongation and high structural strength. Films or layers of
such
multilayer packaging materials are e.g. made of a polymer such as e.g. thermo-
plastics, cellulose-containing materials such as e.g. paper or parchment, or
are of
metal such as e.g. aluminium or an aluminium alloy.
Flexible forms of packaging are for example pouch-shaped packaging such as
flat
pouches, edge-sealed pouches, shaped pouches, self-standing pouches or tube-
like pouches. Accordingly, the pouches exhibit at the edge on at least one
side a
closure seam e.g. a sealing seam such as a hot or cold sealed seam, welded
seam or adhesive seam. Depending on the manner of manufacture, flat pouches
may for example exhibit three or four sealing seams at the edges on three or
four
sides. A tube-shaped pouch on the other hand may exhibit an upper and an
opposite lying lower transverse seam or an upper and a lower transverse seam
and a seam on the body such as an overlapping or folded seam.
Such forms of packaging are suitable e.g. for packaging dry pourable goods,
liquids or specific solid goods, in particular those belonging to the
categories of
foodstuffs and semi-luxury goods. Flat pouches or edge-sealed pouches serve
especially the purpose of packaging substances in powder form, soluble coffee
or
crystallised sugar. Chocolate bars or biscuits are packaged for sale e.g. in
tube-
like pouches. Milk products such as yoghurt and drinks are preferably packaged
in
shaped pouches.
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To remove the contents from a pouch with a tear-open closure, the pouch
material is torn open at one end. As the laminate film is designed to be
resistant
to tearing, the tearing process is normally made easier by means of an aid to
tearing provided in the region of the opening. The tearing action is carried
out
along a tearing line along which the packaging is separated in at least two
parts
and which passes at least in part through the contents space of the packaging.
The line of tearing may pass through the packaging in a controlled or
uncontrolled
manner. Subsequently, the contents can be removed as desired through the
opening created in the packaging.
Generally, on tearing open the packaging, a relatively small part of the
packaging
is torn off viz., a part which usually represents useless waste for the
consumer. As
a rule, the torn off part has to be put aside before removing the contents of
the
packaging i.e. disposed of in order to free the hands for further manipulation
pur-
poses. Often these small parts are simply thrown away resulting in unnecessary
pollution of the environment.
The object of the present invention is therefore to provide packaging with
tear
open closure of the kind described at the start, such that after opening no
separated tear-off parts are produced.
That objective is achieved in that the packaging contains a tear-arresting
means
that lies on a tearing line in the direction of tearing in the form of an
opening that
partially or wholly penetrates the packaging film or, running essentially
transverse
to the line of tearing, a cut or partially cutting line, perforation or the
like line of
weakness which in part penetrates the packaging film, this in such a manner
that
a tearing zone progressing along the tearing line is no longer effective on
meeting
the tear-arresting means and the tearing process is stopped.
The tearing line is that stretch in the packaging film along which a tearing
zone
propagates and where the packaging is separated into at least two parts,
whereby
by "tearing zone" is to be understood that place on or in the packaging film
where,
under application of the necessary separating forces, the tearing open action
starts or progresses. As a rule the tearing zone is described by that place at
which
two edges or the edges of two separating lines run together at an acute to
obtuse
angle - in particular at an acute angle - at a common cutting point. In this
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connection the separating line is to be understood to be a cut running through
the
packaging film.
The tearing zone may e.g. be an end region of a separating line or a notch
running together at an end point at an acute angle.
In order that the separation of the packaging film runs along a predetermined
i.e.
controlled tearing line, the latter may be in the form of a partially cutting
line,
perforation or the like line of weakness, pre-fabricated in the packaging
film, this
in order to reduce the resistance to tearing or to effect controlled tearing.
The
tearing line may, without lines of weakness and the like, propagate in a more
or
less controlled manner in a pre-determined direction in the packaging film,
this
starting from an aid to tearing and as a result of the structure of the
packaging
film.
By partially cutting line is to be understood a line of cut which passes
through only
a part of the layers of film or individual films of the packaging film and
consequently penetrates the packaging film only in part.
By a "line of weakness" is to be understood in this text a so-called intended
tearing place in the form of a line or a limited elongated length of area
which
exhibits much lower resistance to tearing than the rest of the packaging or
wall
film and tears under a specific tensile load, whereby e.g. a tearing movement
with
the hands suffices for that purpose. The line of weakness may be created e.g.
by
local weakness of a limited part of foil by means of chemical, physical or
mechan-
ical means.
The packaging may exhibit an aid to tearing, whereby the aid to tearing may be
in
the form of a potential tearing zone and is e.g. a notch provided in the
packaging
film. Further, the aid to tearing may contain one or more cut or partially cut
lines,
perforations or the like lines of weakness passing completely or only
partially
through the wall of the packaging film.
Further the aid to tearing may contain a tearing strip which e.g. is situated
between two layers of material. Pulling on the tearing strip then effects
separation
of the packaging material along a controlled tearing line. The tearing strip
runs
however preferably only to the tear-arresting means.
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The aid to tearing open a packaging according to the invention preferably lies
in
the region of a closure seam and/or in regions in which the composite material
is
present in two or three layers as a result of folding and/or sealing. The aid
to
tearing may, in particular when it involves partially cut lines or
perforations or the
like lines of weakness, extend for example from the outer limit of a closure
seam,
through this and up to the packaging film delimiting the contents space.
The aid to tearing may be created before production of the packaging e.g.
during
manufacture of the packaging film, or after production of the packaging.
Further,
the provision of the aid to tearing may be integrated in the continuous
manufacture of the packaging or package and may be applied e.g. before, during
or after the manufacture of the packaging or packing.
Usefully, the tearing line runs in lengths along or across at least one
closure
seam. Known for example are pouch type forms of packaging, in particular non-
flat pouches for pourable dry or liquid contents having at least one closure
seam
and a tube-like, neck-shaped or pipe-shaped opening region projecting into the
seam. As a rule an aid to tearing is provided at the edge of the said closure
seam,
from which the tearing line runs through a length of closure seam and then
through the tube-shaped opening region that corresponds with the contents
space, and again further along the closure seam.
The tearing line may also run, starting from a first edge of the packaging -
if
desired delimited by a closure seam - through the contents space and into a
further closure seam that lies opposite the first edge of the packaging,
delimits the
edge of the packaging and lies vertical to the tearing line.
To open the packaging, this is divided along the tearing line - starting from
the aid
to tearing - into two parts viz., a relatively small part which is torn back
and the
rest of the packaging, whereby during the opening process a tearing zone propa-
gates along the tearing line.
In order to terminate the tearing process before the small part is separated
from
the rest of the packaging the tear-arresting means is provided in separating
direction of the tearing line, this to eliminate or inactivate the tearing
zone.
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The tear-arresting means lies preferably in a closure seam e.g. at the side or
the
top. In order to ensure that the air-tightness of the packaging is maintained,
a
sufficiently broad closure seam strip is preferably provided between the tear-
arresting means and the contents space.
10
If there are places in the packaging where the packaging material is present
in
several layers as a result of folding or adhesive bonding, then the tear-
arresting
means may also be situated in these zones. In the case of forms of packaging
with a body seam, the tear-arresting means may be situated in this seam.
In a particularly favoured version of the invention the openings forming the
tear-
arresting means are in the form of a circle, an oval or an ellipse. Usefully
the
tearing line runs in the middle of the said opening so that on entering the
opening
the tearing zone is eliminated. As a result of its shape the opening described
above does not form a tearing zone or aid to tearing in the direction of
tearing and
hinders therefore further progress of the tearing process. The tearing process
can
be propagated further only by applying above average force.
The tear-arresting means in the form of an opening may also include a length
of
arc, oval or an ellipse. Further, the opening in question may also be crescent-
shaped, whereby the opening as viewed in the direction of tearing makes a
concave arc through the tearing line.
The opening of the tear-arresting means usefully runs completely through the
packaging film. It may, however, be made such that only individual or several
layers of film are provided with an opening of the kind mentioned above.
The tear-arresting means in the form of an opening, in particular a round
opening
may also serve as a means for hanging the packaging or package up in a display
stand.
In another version of the invention the packaging contains as tear-arresting
means at least one cut or partially cut line, perforation or the like line of
weak-
ness. The tear-arresting means in that version preferably runs essentially
transverse across the line of tearing. In turn the line of tearing preferably
runs into
the middle of the line or perforation forming the tear-arresting means.
Further, as
viewed in the direction of tearing, the above mentioned line or perforation is
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preferably essentially concave in shape. Usefully, the ends of the cut or
partially
cut line, perforation or the like line of weakness run essentially counter to
the
direction of tearing.
The above mentioned cut or partially cut line, perforation or like line of
weakness
employed as tear-arresting means preferably takes the form of a part of a
circle,
part of an oval or part of an ellipse, whereby the ends of the line are
oriented
essentially counter to the direction of tearing. The ends of the cut or
partially cut
line, perforation or like line of weakness also form tearing zones or aids to
tearing,
but these are effective only counter to the direction of tearing and so have
no
effect in that respect.
It is also possible to provide only those layers of packaging film that are
more
resistant to tearing with a tear-arresting means in the form of a cut line
The tear-arresting means i.e. the edges of the opening or the cut or partially
cut
line, perforation or like line of weakness may in addition be reinforced in
order to
make further tears forming in the region of these edges more difficult. The
reinforcing may be achieved e.g. by altering the film structure locally e.g.
by
heating or embossing.
The packaging film is single-layered or preferably a multi-layered. The
individual
layers of material may be coating layers, films of metal, metallised layers or
plastic
films, in particular thermoplastics or composites made up of metal foils and
plastic
films. One or more layers of material may be extruded and in particular melt
extruded layers or films of thermoplastics, in some cases combined with metal
foils or plastic films. At least one layer of material may be a lacquer
coating which
may be transparent or coloured, a hot-melt coating etc. At least one layer of
material may be a metallised layer or a thin ceramic layer deposited in
vacuum.
Between the individual layers there may be adhesives, extrusion adhesives,
bonding agents and/or primers. In order to increase the bonding between the
layers the surfaces of the films, coatings or material layers may be subjected
e.g.
to a corona, flame, ozone or plasma treatment.
The material layers of thermoplastics may be transparent, translucent or
opaque.
The layers of material, in particular those outermost lying layers of
material, foils
or coatings on the packaging may exhibit printing.
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The wall thickness of the packaging film is e.g. 10 - 500 Vim, preferably 50 -
300
Vim, in particular 50 to 150 Vim.
Metal foils which may be employed are e.g. steel foils and in particular
aluminium
foils. The thickness of the foils may be e.g. from 5 to 100 Vim, preferably 8
to 45
pm, in particular from 10 to 35 Vim.
Suitable films of plastic are usefully those made of thermoplastics such as
poly-
esters, polyolefins, e.g. polypropylenes or polyethylenes, or such as
polyamides,
polyvinylchloride, polycarbonate or of cellulose-containing materials such as
cellophane or paper. The films of plastic may be in the form of monofilms or
as
laminates. The thickness of the plastic films may e.g. be from 8 to 100 Vim,
preferably from 12 to 35 Vim, and in particular 12 to 23 Vim.
Extruded or melt-extruded layers may e.g. be of polyolefins such as polypropyl-
enes or polyethylenes. The thickness of the extrudates may e.g. be from 8 to
100
Vim, preferably from 12 to 30 ~,m and in particular 12 to 23 Vim.
The side of the packaging film facing the inside of the packaging is to
advantage
sealable. In some cases the outward facing side of the packaging film may also
be sealable.
Examples of a multi-layered packaging film are laminates containing a first
layer
of material and a second layer of material. The first layer of material may be
a film
such as a monofilm or laminate made of thermoplastics such as polyesters, poly-
olefins, such as polypropylenes or polyethylenes, or polyamides, polyvinyl-
chloride, polycarbonate etc. or cellulose-containing materials such as
cellophane
or paper. The second material layer may be e.g. a metal foil or a metal foil
with a
sealing layer which is on the side that faces the inside of the final
packaging and
viz., such as a sealing coating or sealable film. In a further version the
second
material layer may be a sealable thermoplastic film or an extrusion layer of a
thermoplastic, which is preferably sealable. If desired also papers e.g.
coated
papers may be employed as the second material layer. If desired one may also
employ also lacquer coatings or lacquer deposits as the second material layer.
Depending on the goods to be packaged the packaging film may exhibit barrier
properties against the passage e.g. of fluids, gases, vapours, water vapour,
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aromas or substances that smell. To achieve the desired barrier properties it
is
possible to employ metal foils, metallised layers e.g. of aluminium, thin
ceramic
layers e.g. of silicon oxides and/or aluminium oxide, which are deposited by
sputtering or deposition in vacuum, or plastic films e.g. of materials such as
styrole-copolymers of ethyl-vinyl-alcohol polymers or of
polyvinylidenchloride.
Examples of sealable materials for the films or extrudates are polyolefins
such as
polyethylenes, polypropylenes or copolymers and terpolymers of ethylene with
acrylic acid. The sealing ability of the laminate material may also be
achieved by
depositing a sealing lacquer.
The present invention also relates to a packaging film for manufacturing a
packaging according to the invention having a tear-arresting means. The packag-
ing film is characterised in that this is film-shaped, is single or multi-
layered or
multi-coated and if desired contains a pre-fabricated tear-arresting means.
The described packaging film may also contain an aid to tearing and/or a
predetermined tearing line in the form of a cut or partially cut line,
perforation or
the like line of weakness.
The present invention also relates to a process for manufacturing a packaging
film
with tear-arresting means. The packaging is manufacturable in that during or
after
the production of the packaging film a tear-arresting means is created at a
pre-
determined place by means such as blades, stamping blades or needles or by
energy intensive radiation preferably laser beams or electron beams.
The blades may be e.g. oscillating blades or rotating blades mounted on a
cylinder. Energy intensive radiation such as laser beams or electron beams are
employed in particular to create micro-perforations.
The tear-arresting means is introduced e.g. before processing the packaging
film
into a form of packaging. The tear-arresting means may be created in
particular
during or after the production of the packaging film. Further, the tear-
arresting
means may be created during or after the production of the packaging, whereby
the process step in question is integrated to the greatest possible degree in
the
continuous production process. To that end an additional facility such as a
cutting
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or stamping device for creating the tear-arresting means may be built in or
integrated into the packaging machine at the appropriate place.
The tear-arresting means may be introduced during the production of the
packaging film. The packaging film may be manufactured e.g. by providing a
first
layer of material, in some cases with the printing on one or both sides of
that layer
and simultaneously creating the tear-arresting means in the register, so that
the
tear-arresting means and the printing are always in the same position with
respect
to each other. The tear-arresting means may e.g. be provided in only
individual
layers of material. It is also possible to create the tear-arresting means
before
depositing a lacquer or protective coating.
Analogous to the tear-arresting means it is also possible to provide
additional aids
to tearing. The tear-arresting means and the aids to tearing are preferably
created
in the packaging film or package simultaneously or in steps following
immediately
one after the other
The tear-arresting means is created e.g. continuously in a packaging film in
the
form of an endless strip or roll. It is also possible to process sheets.
The packaging film may e.g. be introduced into a packaging machine in the form
of an endless strip or roll and employed for the packaging of various goods.
As a
result of the manufacturing process described above the printing and the tear-
arresting means and if desired the aid to tearing in the laminate material are
situated such that they cannot change. A high quality packaging is such that
the
printing is always situated in alignment with the size of packaging and the
contents in question. Thus by employing the described packaging film the tear-
arresting means which is always correctly aligned with the printing is always
at the
same place on each packaging unit.
Typical packaging units are, as viewed in plan view, e.g. polygonal,
elliptical or
lens-shaped and from the side e.g. polygonal and in particular rectangular.
The present forms of packaging are suitable e.g. for containing fluid,
powdered,
granulated, solid or pasty contents. Fluid contents range from drinks, juices
etc. to
cleaners and the like. Typical examples of contents are foodstuffs and semi-
luxury
substances in power and granulated form such as ready-made soups, instantly
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soluble coffee, coffee powders, pudding powders, spices etc. The solid
contents
may be in block or bar form e.g. chocolate and muesli bars. In addition the
packaging may be employed for pasty foodstuffs such as yoghurts and other milk
products, and for other pasty substances such as e.g. body-care and cos-metic
substances, such as shampoos or lotions or substances such as pharma-
ceuticals. Also the packaging according to the invention may be employed for
packaging medical devices or applicators and technical items.
Further advantages, features and details of the invention are revealed by way
of
the following description of preferred exemplified embodiments and with the
aid of
the drawing which shows in
Fig. 1 a a side elevation of a pouch-shaped packaging;
Fig. 1 b a part of a side elevation of an opened pouch-shaped packaging as in
figure 1 a;
Fig. 2a a part of the opening region of a further pouch-shaped packaging
shown in side elevation;
Fig. 2b a part of an opening region of a further pouch-shaped packaging
shown in side elevation.
Figure 1 a shows a pouch-shaped packaging 1 with a contents space 6 and peri-
pheral sealing seams (5, 10). The pouch-shaped packaging 1 serves in
particular
to accommodate drinkable fluids. The opening region is in the form of an
opening
neck 7 which projects into an upper sealing seam 5 and is integrally connected
to
the contents space 6. Both side edges and the upper edge of the opening neck 7
border onto the sealing area of the upper sealing seam 5. At the side of the
opening neck 7, in the edge region of the upper sealing seam 5, is an aid to
tearing 2 in the form of an initiating notch. Starting from the aid to tearing
2 a
tearing line 3 runs in the tearing direction (x) across the opening neck 7 and
through the upper sealing seam 5 in its longitudinal direction. The tearing
line 3
may be pre-marked by a perforation, partially cut line or line of weakness in
order
that the separation is controlled on opening the pouch.
The pouch 1 also contains a drinking straw 8 which permits direct consumption
of
the fluid contents after opening.
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A tear-arresting means 4 is provided in the tearing line 3 in the upper
sealing
seam 5 in the form of a circular opening.
By tearing the pouch 1' at the tearing aid 2 and tearing the pouch 1' in the
direction (x) a strip 9 is formed along the line of separation and runs to the
tear-
arresting means 4 (Fig. 1 b). At the tear-arresting means 4 the tearing
process
halts and the edge region of the opening offers no further aid to propagating
the
tear.
The drinking straw 8 reaches preferably beyond the tearing line 3 so that,
after
tearing open the pouch 1', the drinking straw projects a certain distance out
of the
opening in the pouch ready for use.
Figure 2a shows a section of a further pouch-shaped packaging 11 having an
upper sealing seam 12 and a contents space 6, whereby a tearing line 3 runs
through the upper sealing seam 12. The tearing line is delimited by a tear-
arresting means 13 in the form of an arc-shaped cut line. The arc is concave -
as
viewed in the direction of tearing (x).
Figure 2b shows a section of a further pouch-shaped packaging 14 having an
upper sealing seam 15 and a contents space 6, whereby a tearing line 3 runs
through the upper sealing seam 15. The tearing line is delimited by a tear-
arresting means 16 in the form of a semi-circular opening. The semi-circular
cut is
concave - as viewed in the direction of tearing (x).
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