PILE COMPRENANT UNE PLURALITE DE SACS ALLONGES DE PELLICULE PLASTIQUE RELIES L'UN A L'AUTRE, EN PARTICULIER LES SACS CONVENANT AUX JOURNAUX, ET METHODE ET MACHINERIE SERVANT A LEURFABRICATION

STACK COMPRISING A PLURALITY OF ELONGATED BAGS OF PLASTIC FILM THAT ARE JOINED TO EACH OTHER, IN PARTICULAR SUCH BAGS INTENDED FOR NEWSPAPERS, AND A METHOD AND MACHINERY FOR MANUFACTURING THESE

Abrégé anglais

The present invention relates to a stack made up of a plurality of bags (1),
in particular
newspaper bags, that are blocked together and which, in order to ensure a
manufacturing
process that is simple and above all else can be conducted at a high cyclic
rate, has in the area
of an insertion opening (2) a suspension strip (13) that is welded on and is
manufactured by
separator welding tools (33, 34) that are preferably arranged in a twin
configuration and are
fed to a subsequent collector (35).

Revendications

Claims
1. Stack made up of a plurality of elongated bags that are of plastic film, in
particular
newspaper bags, that are joined to each other, with preferably at least one
additional
pocket in the area of an insertion opening for the bag, and with a suspension
element
that has at least on suspension opening and is joined to each bag in the stack
so as to
be removable therefrom, characterized in that the suspension element (13) is
formed
by a tear-off section of plastic film that projects from one side.
2. Stack as defined in Claim 1, characterized in that the tear-off section is
formed from a
separate tab (13) that is welded to one wall of the bag in the area of the
insertion
opening (2), essentially parallel to a line of perforations (11).
3. Stack as defined in Claim 1 or Claim 2, characterized in that the tab (13)
is welded to
the outer or inner side of the bag (1) and is provided optionally with a draw
strip (42)
or a rain flap (43) with an adhesive strip (44) at its insertion opening (2).
4. Stack as defined it in one or more of the Claims 1 to 3, characterized in
that the pocket
(5) is attached to the end of the bag (1) that is opposite the insertion
opening (2) and
that at its filler opening (10) that extends essentially parallel to the
insertion opening
(2) has a flap (8) that projects on one side.
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5. Stack as defined in Claim 4, characterized in that the flap (8) is
preferably formed in
one piece from the same material, preferably a transparent plastic film, as
the pocket
(5).
6. Stack as defined in Claim 4 or Claim 5, characterized in that the flap (8)
lies on the
same side as the tab (13).
7. Stack as defined in one or more of the Claims 1 to 6, characterized in that
the flap is
provided on the inside with an adhesive strip (9) that can optionally be
covered by a
protective strip.
8. Method for the continuous production of bags that are of plastic film, in
particular
newspaper bags, that are combined to form a stack, preferably with at least
one
additional pocket, a first and a second web of plastic film for the bag and
optionally a
third web of plastic film for the pocket being continuously supplied and
welded
longitudinally and transversely to form longitudinal and transverse welded
seams, as
well as an insertion opening of the bag and the filler opening for the pocket,
with a
suspension element being attached in the area of the insertion opening,
characterized
in that the suspension element is welded to one wall of the bag, in the area
of the
insertion opening, in the form of a continuously supplied tab strip of plastic
film.
9. Method as defined in Claim 8, characterized in that the plastic film of the
tab strip is
of material other than the plastic film used for the bag.
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10. Method as defined in Claim 8 or Claim 9, characterized in that in order to
form a flap,
the web for the pocket is fed to a base seam of the bag, offset to the
outside.
11. Device for the continuous production of stacks made up of a plurality of
bags that are
of plastic film, in particular newspaper bags, that are joined to each other,
preferably
with at least one attached pocket, with a supply station, at least one
longitudinal
welding device, a punching device, and a connecting device, as well as a
transverse-
cut welding device and a collector, characterized in that the connecting
device is in the
form of a blocking machine and that, in addition, a tab-strip supply station
(25) is also
provided.
12. Device as defined in Claim 11, characterized in that an adhesive-strip
supply station
(27) and optionally a protective-strip supply station are also provided.
13. Device is defined in Claim 11 or Claim 12, characterized in that the
transverse-cut
welding device (32) has two separator welding tools (33, 34) that are
essentially
transverse the direction of feed of the web of plastic film and can be moved
synchronously up and down.
14. Device as defined in one or more of the Claims 11 to 13, characterized in
that the
collector (35) that is arranged after the separator welding tools (33, 34) as
viewed in
the direction of feed of the web of plastic film (19, 21, 22) has stacking-pin
belts of a
stacking-pin conveyor (39) in which the bags (1) are picked up in the area of
the tab
strip (13) by pins (41) of the stacking-pin conveyor, the bags being held by
pins on
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the transport belts (38) as far as the stacking-pin belts, and removed in the
area of their
stacking-pin conveyor (39) by a removal device and subsequently blocked
together in
the area of the tab-strip (13).
15. Device as defined in one or more of the Claims 12 to 14, characterized in
that the
draw-strip supply station is provided, by which a draw strip is supplied to
the area of
the insertion openings (2) of the bag (1).

Description

CA 02350547 2001-06-14
Stack Comprising a Plurality of Elongated Bags of Plastic Film that are Joined
to Each
Other, in Particular Such Bags Intended for Newspapers, and a Method and
Machinery for
Manufacturing These
The present invention relates, first, to a stack comprising a plurality of
elongated bags that are
of plastic film and joined to each other, in particular, such bags as are
intended for
newspapers, preferably with at least one additional pocket, with at least one
suspension
opening in the area of the insertion opening for the bag, and a suspension
element that is
joined to each bag in the stack so as to be removable therefrom.
Bags of the type discussed herein are used, in particular, to provide a large
measure of
protection against the weather for newspapers, magazines, or the like. Very
often, these
elongated bags incorporate an additional pocket in which a diskette or the
like can be
inserted.
As a rule, some 10 to 20 , at most 25, such bags are combined to form a stack
and are held
together by a cardboard handle strip. This handle strip, which serves as a
suspension element
can be secured at the edge of a tear-off tab by clasps.

CA 02350547 2001-06-14
For practical purposes, a stack up of this kind is carried by a newspaper boy
who, when so
required, and if this has not already been done, fills a bag with a newspaper
or magazine in
order that the filled bag can be torn off the stack and then placed in a
position that is
accessible to the recipient.
The use of three different materials, namely, cardboard for the handle strip,
metal for the
clasps, and plastic for the actual bag results in considerable recycling
costs, since these
materials have to be collected separately from each other. In addition,
manufacturing bags of
this kind is extremely difficult, so that in practice such bags can only be
manufactured at a
speed of some 40 to 60 cycles per minute.
It is the objective of the present invention to produce a stack comprising a
plurality of
elongated bags that are of plastic film, in particular such bags as are
intended for newspapers,
which are joined to each other, and which can be transported and handled
easily. In addition,
the present invention proposes a method for manufacturing bags of this kind
that can be
combined to form a stack, whereby a simple and cost-effective manufacturing
process is
made possible. Finally, machinery is to be created that to a large extent uses
familiar
assemblies and makes it possible to manufacture bags of the type discussed
herein at a
comparatively high cyclic rate.
From the standpoint of the product, the objective of the present invention has
been achieved
in that the suspension element is formed by a tear-off section of plastic film
that protrudes at
one end of the bag. This tear-off section can be formed, for example, from a
separate tab that
is welded to one wall of the bag in the area of the insertion opening,
essentially parallel to a
2

CA 02350547 2001-06-14
line of perforations. The insertion opening can be closed advantageously by a
draw string or a
rain flap.
A further advantageous feature of the present invention is that the pocket is
attached to the
end of the bag that is opposite the insertion openings, and that on its filler
opening, which is
essentially parallel to the insertion opening, this pocket has a flap that
projects on one side.
If necessary, this can be made in one piece from the material used for the
pocket and can be
provide on its inner side with a strip of adhesive that can if necessary be
covered by a
protective strip.
From the standpoint of the machinery that is used, the present invention is
distinguished
mainly in that the device that is used to join the individual bags to each
other in the stack is
configured as a blocking machine and in that, in addition, a tab-strip supply
device is also
provided. The continuous feed of a tab strip makes it possible to achieve a
comparatively high
cyclic rate of, for example, 100 to 125.
This is further facilitated in that the device has two separator welding tools
that are arranged
transversely to the direction in which the web of plastic film is fed and
which can be moved
synchronously up and down, and in that, in addition, the collector that is
arranged after the
separator weld tools as viewed in the direction of feed of the plastic film
incorporates the
stack- pin belts of a stack-pin conveyor, in which the bags with the tab
strips are taken from
the stack belts, the bags being held by the pins on the conveyor belts as far
as the stack belts
and then discharged in the area of the stack-pin conveyor by a removal device,
and are then
blocked with each other in the area of the tab-strip.
3

CA 02350547 2001-06-14
Preferred embodiments of the bags that are discussed herein are shown in the
drawings
appended hereto. These drawings show the following:
Figure 1: a newspaper bags that has been cut off and is used to contain a
newspaper and
a diskette;
Figure 2: different versions of the suspension area of the newspaper bag;
Figure 3: a stack made up of a plurality of bags as shown in Figure 1;
Figure 4a and 4b: a plan view of a machine used to manufacture newspaper bags;
Figures Sa and Sb: the associated side view;
Figures 6 to 10: additional, modified embodiments of the bag.
The bag 1 that is shown in Figure 1, which is of plastic film, has at its
upper end an insertion
opening 2 that extends as far as a lower bottom seam 3 of the bag and serves,
for example, to
hold a newspaper 4, a magazine, or the like. In the lower area of the bag 1
there is a pocket 5
that is similarly of plastic, for example transparent plastic, and is welded
to one wall of the
bag 1 by a welded seam 6. This pocket is used as an advertisement pocket and
can be used,
for example, to hold a diskette 7, as is shown in Figure 1. A flap 8 is
provided to close the
pocket 5, and this is arranged either in an extension of the bag 1, as is
shown in Figure 1, or it
can be formed from an offset extension of the bags material. In any case, the
flap is provided
with an adhesive strip 9 so that once the diskette has been inserted, the
pocket can be closed
off at the lower end. If the pocket is not used, the adhesives strip 9 can be
covered by a
protective strip (not shown herein).
4

CA 02350547 2001-06-14
At the upper end of the bag, i.e., in the area of the insertion opening 2,
there is a line of
perforations 11 in the rear wall of the bag. A suspension element in the form
of a tab-strip 13
that is of plastic is welded essentially parallel to this line of perforations
by way of a welded
seam 12. The tab strip 13 incorporates a suspension opening 14 and, if
necessary, stack-pin
openings 15 and blocking points 16. A plurality of bags is combined to form a
stack 17 using
these blocking points 16, as is shown in Figure 3.
Figure 2 shows different suspension openings in the suspension element 13.
These are
configured depending on the purpose of the bag and their utility. Above all,
it is possible to
select the shape of the suspension element and/or the thickness of the
material that is used, as
is required.
Figures 4a and Sa show a supply station 18 that is used to feed a first web
19, a second web
21 for manufacturing the bag, and a supply device 22 for a web (not shown in
detail herein)
for manufacturing the pocket 5. In order to produce the appropriate, necessary
longitudinal
welded seams, the webs are passed along a first longitudinal welding machine
23 and a
second longitudinal welding machine 24. In addition, reference point 25 shows
an additional
feed station for the tab strips, which is not shown in detail in Figures 4a
and Sa. A strip
deflection system is shown at reference point 26. An adhesive-strip feed
station 27 and an
adhesive application station 28 are also provided. Beneath the adhesive-strip
feed station
there is a longitudinal perforating device 29, and a machine for punching the
holes in the
handle is shown at reference point 31.

CA 02350547 2001-06-14
The machinery shown in Figure 4b and Sb is used for the further production of
the bag
according to the present invention. Essential for the present invention is a
transverse-cut
welding device 32 that incorporates two welding tools 33, 34 that are arranged
essentially
transversely to the direction of movement of the webs and can be moved
synchronously up
and down; the spacing between these two welding tools is equal to twice the
width of a bag
section of the web of plastic film. Thus, two bags can be manufactured in each
cycle of the
machinery.
In practice , the bag or the pocket can be filled by machine, although this is
not shown herein.
In order to achieve the comparatively high cyclic rate of at least 100 to 125,
a collector 35 is
arranged after the separating welding device 32; this is described in greater
detail below.
First, the collector has a conveyor 36 that extends on one side into the area
of a guide table 37
or of guide belts in the area of the transverse-cut welding device 32. The
conveyor 36 has
endless belts 38 that are routed about guide rollers. The belts can be
provided with pins that
can penetrate the edges of the bag when the bag is moved in the direction of
feed. By this
means, the bags can be moved into the area of a stacking pin conveyor 9 that
lies partially
beneath the transport device 3G. The bags on the stacking pins 41 of the
stacking-pin
conveyor can be moved off by a removal device (not shown in detail herein) and
gathered into
stacks. Before the bags that are stacked in packets are removed, they are
blocked together by a
blocking device (not shown herein).
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CA 02350547 2001-06-14
Figure 6 and Figure 7 show the configuration of the bag as a so-called draw-
string bag. Once
it has been removed from the stack 17, a bag of this kind can be closed at the
insertion
opening 2 by a draw tape or string 42.
Another alternative is shown in Figure 8 to Figure 10. In this embodiment, the
bag 1 can have
the insertion opening 2 closed by a rain flap 43 that is secured by an
adhesive strip 44.
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Dessin représentatif