Note: Descriptions are shown in the official language in which they were submitted.
u l I. .
CA 02570727 2006-12-08
METHOD FOR PRODUCING A PACKAGING MEANS AND PACKAGING MEANS
MADE OF FLEXIBLE MATERIAL
BACKGROUND OF THE INVENTION
The invention relates to method for producing a packaging
means made of a flexible material, in particular for
producing a side gusset bag made of plastic film.
Furthermore, the invention relates to a packaging means
made of a flexible material, in particular side gusset bags
made of plastic film, comprising a front wall and a rear
wall between which side gussets extending over sections of
their lateral areas are disposed, said side gussets being
designed to be shortened in the upper region of the
packaging means, the packaging means having a gusset-free
head region between the front and rear wall.
It is known to produce a packaging means made of a flexible
material, for example, a side gusset bag made of a plastic
film, by arranging two material webs congruently with
respect to one another and positioning predefined
functional elements between said material webs and
optionally bringing into contact with the material webs.
Subsequently, predefined regions of the material webs are
joined to one another and the finished packaging means is
separated as sections from the joined material webs. The
known methods are very complex and very expensive to
implement.
SUMMARY OF THE INVENTION
It is the object of the invention to provide a method for
producing a packaging means which is comparatively easy to
implement and at the same time allows the packaging means
to be produced at a favourable cost.
This problem is solved by a method according to the
invention for producing a packaging means made of a
. i. .
CA 02570727 2006-12-08
- 2 -
flexible material, in particular for prodtzcing a side
gusset bag made of plastic film, in which a single flexible
material web is folded in the longitudinal direction,
superposed layers of the folded material web are firmly
bonded to one another and at least one section of the
material web is constructed as a tubular piece, individual
gusset edges of the material web constructed as a tubular
piece are at least partly cut, and then tubular pieces of a
predetermined length are cut from the material web, in the
area of at least one opening of the tubular piece its outer
layers are turned over and layers of the material located
therebetween are shortened, a sealing element is applied to
the ends of the shortened layers and brought in contact
with one of the outer layers, the shortened ends are closed
after re-turning the outer layers and fixed to a respective
outer layer and predefined regions of superposed layers of
the tubular piece are firmly bonded to one another.
The method according to the invention can advantageously be
used to produce a packaging means from a material web which
allows the packaging means to be produced simply and
therefore cost-effectively by means of the process features
according to the invention.
According to a further development of the invention, it is
particularly advantageously provided that the material web
is folded in such a manner that its longitudinal sides are
superposed in one of the lateral regions of the folded
material web. As a result of the advantageous folding of
the material web and the superposition of the longitudinal
sides in particular in the area of a side gusset, the
entire width of the material can advantageously be used.
After folding the material web, the superposed longitudinal
sides are firmly bonded to one another. The firm bonding
creates a firm or permanent and therefore advantageously
secure contact between the superposed longitudinal sides.
CA 02570727 2006-12-08
- 3 -
The firm bonding can be effected, for example, by a
specific supply of heat along pre-determined sections of
the superposed longitudinal sides of the folded material
web, wherein predetermined sections of the material web can
be formed into a tubular piece.
In a further development of the method according to the
invention, the gusset edges in the lateral regions of the
material web are firmly bonded to one another jointly with
the superposed longitudinal sides over a predefined section
of their extension. The additional firm bonding of all the
gusset edges of the material web advantageously imparts
more stability to the tubular piece produced, which is why
further processing is simplified and the packaging means
filled with the products has improved dimensional
stability.
In a further processing step according to the invention,
certain regions of the material web are cut away along the
firmly bonded gusset edges. The cuts made on both sides of
the material web which is almost equivalent to a trimming
of edge regions advantageously opens predetermined sections
of the lateral regions of the material web. In particular,
it is possible for the cutting tools to be brought in
contact with the gusset edges, for example, only at
predetermined intervals so that interrupted cutting
profiles are formed along the gusset edges.
Alternatively, it is provided according to another further
development of the method according to the invention that
predetermined sections of the gusset edges are cut open.
Cutting open the gusset edges has the advantage that no
material clippings are formed at the gusset edges and thus
the width of the folded web is advantageously preserved.
The tubular pieces are separated from the material web in
such a manner that the opened lateral regions are embodied
+ 1 1 CA 02570727 2006-12-08
- 4 -
as sections of different length at a respective end of each
tubular piece. The individual formation of the opened
lateral regions at the respective end of each tubular piece
is effected by trimming the tubular pieces and allows an
advantageous configuration of the tubular pieces with
regard to their further processing so that the completion
of the packaging means, in particular the firm bonding at
the ends of the lateral regions can advantageously be
carried out in a simplified manner. It is naturally
possible to vary or adapt the length of the ends of a
tubular piece opened in the lateral regions during
production.
The separated tubular piece is turned in its horizontal
position through about 900 for further processing. The
turning of each tubular piece whilst maintaining the same
direction of transport advantageously provides the
possibility for carrying out further processing steps on
both sides of the conveyor belt. This results in further
simplified production or a shortened production process ior
the packaging means. After separating the tubular pieces
from the material web, it is also possible to transport the
individual tubular pieces further whilst keeping the
alignment unchanged at an angle of about 90 degrees to the
original direction of motion.
At the ends of each tubular piece, the outer layers are
turned over in the area of both tubular openings and the
layers of the material located therebetween are shortened.
The shortening of the side gussets in the upper region has
the advantage that a gusset-free head region is created
between the outer layers forming the front or rear wall of
the packaging means. The side gussets can also be shortened
by a predetermined amount in the lower area of the tubular
piece which is constructed as the bottom area of the
packaging means, whereby a firm bonding of the tubular
opening can advantageously be achieved in the bottom region
CA 02570727 2006-12-08
_ 5 -
over the entire width of the outer layers. At the same
time, increased stability of the packaging means is ensured
in the bottom region. It is not necessary to use costly
stamping tools to produce an opening in the lower region of
the side gussets by which means the otherwise usual bonding
of the lateral regions is accomplished in the bottom region
of the packaging means.
According to another further development of the method
according to the invention, a sealing element is applied in
each case to the individual upper ends of the shortened
layers. By using two separate sealing elements, a smaller
quantity of sealing element which seals the side gussets is
required to produce a packaging means. In addition, as a
result of the shortened sealing elements which are welded
to the shortened layers or side gussets and one of the
outer layers, corresponding heat must act on a reduced area
so that an energy saving can advantageously be made at the
same time.
A re-closure member is inserted between the outer layers of
the tubular piece above the sealing element and is then
bonded firmly to its inner side. The re-closure member is
inserted in particular in the head region of the packaging
means free from side gussets and can advantageously be
brought into contact with the heat-sensitive inner side of
the outer layers of the packaging means over its entire
width. The outer layers can be heated by a specific supply
of heat in the area of the re-closure member whereby the
inner sides of the outer layers fuse with the re-closure
element and a permanent firm bonding can be achieved.
After re-turning the outer layers, the opened lateral
regions of the superposed layers are firmly bonded to one
another in the area of the tubular openings and then the
outer layers are firmly bonded to at least one of the
tubular openings in the edge region. In order to
CA 02570727 2006-12-08
- 6 -
advantageously first fix the side gussets between the outer
layers of the tubular piece, the opened lateral regions are
preferably first welded together and then the tubular
opening in the bottom region of each tubular piece is
sealed in a leak-free manner. For example, it is possible
that each tubular opening in the bottom region of a
respective tubular piece is sealed by means of two parallel
bonding lines. As a result of the strengthened
configuration of the double-sealed bottom region which can
receive a higher loading, packaging means having larger
dimensions can advantageously be produced.
In order to form a contact area in the bottom region of
each packaging means, projecting material is turned over
and adhesively bonded to one of the outer layers. The
projecting or lengthened material can advantageously be
used to form a flat contact area in the bottom region of
the packaging means so that the individual packaging means
can be stored in a standing position and among other
things, it is possible to achieve a higher packing density
during transport or during storage of the stacked packaging
means. The lengthened outer layers of the tubular piece can
be used as projecting material, for example, whereby the
attachment of a separate material section can
advantageously be dispensed with.
In the case of a packaging means made of flexible material,
in particular side gusset bags made of plastic film,
comprising a front wall and a rear wall between which side
gussets extending over sections of their side regions are
arranged, said gussets being embodied as shortened in the
upper region of the packaging means, which can be produced
in particular by a method according to claims 1 to 13. it
is provided according to the invention that each upper end
of the side gussets is closed by a separate sealing element
which fixes the respective side gusset end at precisely one
of the packaging-means walls. Using two separate sealing
CA 02570727 2006-12-08
- 7 -
elements having approximately the width of a side gusset
makes it possible to achieve easy and advantageous filling
or removal of goods to be enclosed or enclosed by the
packaging means. No sealing element is provided in the area
between the side gussets so that the original flexibility
of the material and thus of the packaging-means wall is
preserved. Consequently, the region around the sealing
elements can be deformed relatively easily during filling,
for example, thus ensuring advantageous handling.
Furthermore, a respective side gusset can be fixed either
on the rear wall or on the front wall of the packaging
means by means of the sealing element.
According to a first further development of the invention,
it is provided that each sealing element is firmly bonded
to a respectively allocated side gusset and a respective
packaging-means wall. The adhesive bonding advantageously
creates a firm bond between the sealing elements, the
respective side gussets and a respective packaging-means
wall, whereby individual parts or components of the
packaging means can be permanently and at the same time
securely joined together. Preferably the parts or
components are welded together so that the materials of the
different parts form a non-detachable bond with one
another. It is naturally also possible that other methods,
for example, gluing can be used for the bonding.
It is particularly advantageous if at least one free end of
each sealing element ends between and at the same time at a
distance from the seam edges of at least side seam joining
at least the front and rear wall to one another. The
shortened construction of the sealing elements in the area
of the side seams of the packaging means according to the
invention ensures an improved seal of the side seams. The
firm bonding of the layers to be joined to one another is
thus no longer completely broken, thereby additionally
improving the visual properties of the packaging means
x I I
CA 02570727 2006-12-08
- 8 -
according to the invention. The sealing elements each end
between and at a distance from seam edges of a respective
side seam, the sealing elements preferably being stopped at
half or the centre of the side seam.
Each sealing element is a material strip which can be
brought into contact with the upper ends of the side gusset
and locks this firmly to one of the packaging-means walls.
The use of a material strip in conjunction with the
shortened configuration has the advantage that a PE/PET
composite film, for example, can be used as the material
strip. The composite film can be made from a plurality of
film layers having different properties, at least one film
layer of the composite film having an advantageously low
melting point. When heat is appropriately supplied in the
region of the sealing element, merely this film layer forms
a firm bond with the relevant side gusset and the
corresponding packaging-means wall.
In order to ensure the quality of the goods enclosed by the
packaging means after a first opening of said packaging
means, a re-closure member is arranged in the head region
above the sealing element. The product can advantageously
be removed from the packaging means in a portioned manner
using this re-closure member. At the same time, the re-
closure member creates a flavour seal which, for example,
slows premature drying-out of the enclosed products or
goods or should reduce the absorption of moisture.
The free ends of the re-closure member preferably end in
the side seams and at the same time at a distance from the
outer edges of the side seams of the packaging means so
that predetermined regions of the side seams are not
interrupted. The side seams which are embodied as
continuous at least in part regions effect an increased
sealing of the packaging means according to the invention
CA 02570727 2006-12-08
- 9 -
and therefore a permanently uniform quality of the product
contained therein.
The re-closure member is formed from interlocking elements
which correspond to one another, allowing a re-closable
sealing of the packaging means. The interlocking elements
provide an advantageously simple configuration of a re-
closure member, the interlocking elements intermeshing with
one another in such a manner as to ensure an almost
airtight sealing or closure of the packaging means. A first
interlocking element can, for example, have a groove in
which a hook-shaped web of the second interlocking element
engages over the length of its extension. It is likewise
possible to construct the re-closure element, for example,
as two adhesive strips each assigned to the bag walls.
According to a further development of the invention, it is
provided that the individual interlocking members are
assigned to a respective packaging-means wall. The
interlocking elements which correspond to one another are
arranged in particular in the side-gusset-free head region
of the packaging means on the inner sides of the front or
rear wall. A firm bond is preferably created between the
front or rear wall and the respective interlocking
elements. The firm bonding holds the interlocking elements
firmly and permanently on the inner sides of the packaging-
means walls.
Each side gusset is constructed as shortened in the head
region and in a bottom region. The configuration of a
shortened side gusset at both ends has the advantage that
in particular, in addition to using a re-closure member in
the head region, the shortened side gusset in the bottom
region of the packaging means allows an advantageously
simple joining of the front and rear wall. As a result of
the shortened side gussets in the bottom region, it is not
necessary to provide the individual side gussets with an
I I
CA 02570727 2006-12-08
- 10 -
opening in the region of the bottom welded seam in order to
facilitate the necessary joining of the front and rear
wall.
In an advantageous embodiment it is provided that the front
wall and the rear wall are continuously firmly bonded to
one another in the bottom region. The continuous firm
bonding of the front and rear wall in the bottom region of
the packaging means advantageously ensures improved
formation of the bottom after filling with the products to
be enclosed with the packaging means. In particular, in the
case of packaging means which is to be stored or
transported vertically for example, the continuously bonded
front and rear wall creates an improved contact area. The
inner sides of the front and rear wall of the packaging
means can preferably be welded to one another by
specifically supplying heat in an edge region of the
bottom. Other joining methods, such as gluing for example,
can also be used among other things to join the regions of
the packaging means to be brought into contact with one
another.
According to a further development of the invention it is
provided that the bottom region of the packaging means has
two firm-bonding lines running parallel to one another. The
formation of two firm-bonding lines in the bottom region of
the packaging means allows the formation of a bottom fold
by which means an advantageously flat contact area of the
packaging means can be produced. The bottom fold can be
formed, for example, from the lengthened front and rear
wall which project beyond the side gusset in the bottom
region. The section forming the bottom fold can optionally
be turned over and glued to the outer side of one of the
wall of the bottom region of the packaging means.
The bottom region has at least one diagonal bonding line
which firmly bonds regions of a respective side gusset to a
CA 02570727 2006-12-08
- 11 -
respectively relevant packaging-means wall. The diagonal
bonding lines which can be formed in particular as welded
seams join the side gussets to the packaging-means walls
and ensure an increased stability in the bottom region of
the packaging means and a strengthened contact area
resulting therefrom.
BRIEF DESCRIPTION OF THE DRAWINGS
An exemplary embodiment of the method according to the
invention and an exemplary embodiment of the packaging
means according to the invention from which further
inventive features are obtained are shown in the drawings.
In the figures:
Fig. 1: is a schematic view showing how a material web is
folded;
Fig. 2: is a sectional view of the folded material web;
Fig. 2b: is a schematic plan view of the folded material
web with a firmly bonded section;
Fig. 2c: is a section of a tubular piece separated from
the material web;
Fig. 3a: is a view of the tubular piece turned through 90
degrees in the plane for further processing;
Fig. 3b: is a schematic view showing how the outer layers
of the tubular piece are turned over;
Fig. 3c: is a plan view of the tubular piece with its
shortened side gussets;
Fig. 4a: is a schematic view showing how the outer layers
are turned back in the bottom region and applied
to the upper ends of the side gusset sealing
elements;
Fig. 4b: is a view of the tubular piece with joined side
end sections in the bottom region and an inserted
re-closure member in the side-gusset-free head
region of the tubular piece;
Fig. 4c: is a schematic view showing how the sealing
elements and the re-closure member in the head
x I 1
CA 02570727 2006-12-08
- 12 -
region are firmly bonded to the tubular piece and
core seams are produced in the bottom region;
Fig. 4d: is a schematic view of the packaging means with
closed bottom and joined side end sections in the
head region, and
Fig. 5: is a perspective view of a[packaging means]
according to the invention with shortened side
gussets between the packaging-means walls.
DETAILED DESCRIPTION OF THE EMBODIMENTS
In Fig. 1 reference numeral 1 denotes a material web made
of a flexible material which can be unrolled from a roll 2,
for example. In this case, the material web 1 is folded in
its longitudinal direction, forming several superposed
layers 3 of which two inner layers in each case are
embodied as side gussets. The folded material web 1 is
constructed similarly to a tube, the longitudinal sides 5,
6 of the material web 1 being superposed in the lateral
region 4.
Figure 2 shows a section through the folded material web 1
and is intended to illustrate the structure. Figure 2 shows
the various layers 3 of the folded material web 1, the
material web 1 being folded in such a manner that the
longitudinal sides 5, 6 and the gusset edges 7, 8, 9 form
the lateral edges of the folded material web. Figure 2
further illustrates that the folded material web 1 has two
outer layers 10, 11 and in the lateral regions 4, 12,
layers 13, 14 which are located therebetween in each case
and are embodied as side gussets.
Figure 2b shows how the folded material web 1 in the
lateral regions, in particular the longitudinal sides 5, 6
and the gusset edges 7, 8, 9 are firmly bonded to one
another over a predetermined section of their extension.
The material web is then trimmed at the edges of its
n I I
CA 02570727 2006-12-08
- 13 -
lateral regions so that the layers 10 and 13 or the layers
11 and 14 in the lateral regions are separated from one
another and therefore open in the partial sections 15, 16
of the folded material web 1 which are not firmly bonded to
one another in the lateral regions 4, 12.
Figure 2c shows a tubular piece 16 separated from the
material web 1 which is supplied for further processing.
As illustrated.in Fig. 3a, each tubular piece 17 is turned
through 90 degrees in the horizontal plane before further
processing so that in particular a head region 18 and a
bottom region 19 are accessible for further processing.
Figure 3b shows how the outer layers 10, 11 are turned back
in the head region 18 and also in the bottom region 19 and
therefore the inner layers 13, 14 protrude.
Figure 3c is intended to illustrate how the protruding
inner layers 13, 14 are shortened in the head region 18 and
in the bottom region 19. In this case, as shown in Fig, 3c,
the inner layers 13, 14 can be shortened to different
lengths in the regions 18, 19.
After the shortening, the outer layers 10, 11 are re-turned
in the bottom region, wherein, as shown in Fig. 4a, only
one outer layer 11 is turned back in the head region and a
sealing element 20 is applied to the upper ends of the
inner layers 13, 14 which are also designated as side
gussets.
The schematic side and plan view in Fig. 4b shows how the
returned layers 10, 11 in the bottom region of the tubular
piece 17 are firmly bonded to the respective inner layers
13, 14 in the lateral regions 4, 12. In the head region a
re-closure element 21 is inserted above the shortened inner
layers 13, 14 between the outer layers 10, 11, which re-
CA 02570727 2006-12-08
- 14 -
closure element can be formed, for example, from
interlocking elements which corresponding to one another.
Figure 4c is a schematic view which is intended to
illustrate how a transverse firm bonding 22, 23 embodied as
a welded seam is made in the bottom region 19 between the
outer layer 10 and the inner layer 13 or between the outer
layer 11 and the inner layer 14 and permanently joins the
corresponding layers one to the other. In the head region
18, after folding back the layer 10, the sealing elements
20 are welded to the inner layers 13, 14 and the outer
layer 11, the upper end of the inner layers 13, 14 being
sealed by the respective sealing element 20. At the same
time, the re-closure element 21 is firmly bonded to the
inner sides of the outer layers 10, 11.
Figure 4d shows a schematic diagram of the finished
packaging means in which the tubular opening 24 in the
bottom region of the tubular piece" 17 is sealed by firm
bonding of the outer layers 10, 11 in the last processing
step of the method. At the same time, with the sealing of
the outer layers 10, 11, the inner layers 13, 14 are joined
to one of the respective outer layers 10, 11 and the inner
layers 13, 14 formed as side gussets are sealed at the
lower end in the bottom region 19. In the head region 18 of
the tubular piece 17, the respective upper lateral regions
4, 12 are firmly bonded to one another so that continuously
sealed lateral regions 4, 12 of the packaging means are
obtained and the space located between the outer layers 10,
11 forms a chamber delimited from the surroundings.
Figure 5 shows a packaging means according to the invention
comprising a front wall 25 and a rear wall 26 which are
made of a flexible material, in particular a plastic film.
Side gussets 28, 29 extend between the front wall 25 and
the rear wall 26 in a respective lateral region 27, these
gussets being embodied as shortened in a head region 30 and
i I= I =
CA 02570727 2006-12-08
- 15 -
in a bottom region 31 in each case. The upper ends of a
respective side gusset 28, 28 are each sealed with a
sealing element 32 and at the same time fixed to the rear
wall 26. The side gussets 28, 29 are in each case firmly
bonded to the front and rear wall in the edge regions 33 so
that a firm and at the same time a permanent join is
produced between the individual components of the packaging
means. A re-closure member 34 is arranged in the side-
gusset-free head region 30 of the packaging means, which
member protects the product inside the packaging means from
the prevailing ambient conditions such as moisture in the
air or dust, for example, after the packaging means has
been opened for the first time and the product enclosed by
said packaging means has been removed in portions. The re-
closure member 34 which can be formed in particular from
corresponding interlocking elements, forms a firm bond with
the inner side of the front wall 25 and the rear wall 26.
In order to form a smooth contact area 35 in the bottom
region 31 of the packaging means, the front wall 25 and the
rear wall 26 are constructed as lengthened and are brought
into contact by means of two non-visible firm bonding lines
which run parallel to one another. The bottom fold 36
thereby formed is turned over and glued to the bottom
region 31 of a respective packaging means.
