METHOD AND MACHINE FOR FORMING GRIPPING ELEMENTS IN BAGS FILLED WITH BULK MATERIAL

METHODE ET MACHINE DE FORMAGE D'ELEMENTS DE PRISE DANS DES SACS REMPLIS DE MATERIAU EN VRAC

English Abstract

Machine comprising at least one station (F) for forming
the bag (1) from a tubular element (101), at least one
station (R) for filling the bag with the material (2)
supplied from a supplying apparatus (200) and at least
one station (S) for sealing the mouth (1a) of the bag,
a first and second die-cutting apparatus (500) being
envisaged for forming at least one first opening (6b)
in the zone of the bottom (1b) and at least one second
opening (6a) in the zone of the mouth (1a) of the bag
(1).

Claims

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CLAIMS
1. Method for forming means (6a,6b) for gripping bags
(1) to be filled with bulk products (2), characterized
in that it comprises the following steps:
a) supplying a tubular element 101a to a die-
cutting apparatus;
b) forming at least one opening 6b in a predefined
area;
c) supplying the tubular element 101 to a station
for forming a bag 1;
d) providing at least two welding lines 5b along
the bottom zone lb of the bag 1 and on opposite sides
in the longitudinal direction X-X with respect to said
opening 6b;
e) transporting the bag 1 to the filling station R
and filling the bag;
f) feeding the bag S to a station S for closing
said bag;
g) providing at least two welding lines 5a,
substantially parallel to the transverse direction Y-Y
and at a suitable relative distance in the longitudinal
direction X-X of the bag 1;
h) forming at least one opening 6a in the zone
comprised between the two welds 5a of the mouth 1a of
the bag.
2. Method according to Claim 1, characterized in that
the tubular element is supplied by means of unwinding
thereof from a reel 101a.
3. Method according to Claim 1, characterized in that
the tubular element is centred in position during the
step involving die-cutting thereof.
4. Method according to Claim 1, characterized in that
said at least one opening is a hole.

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5. Method according to Claim 1, characterized in that
said at least one opening is an eyelet extending in the
transverse direction.
6. Method according to Claim 1, characterized in that
the opening (6a) along the side where the mouth (1a) of
the bag (1) is situated is formed during a step
separate from that for performing welds (5a) for
closing the said bag.
7. Method according to Claim 1, characterized in that
the die-cutting is performed in the hot state.
8. Method according to Claim 7, characterized in that
the die-cutting step comprises a step involving taking-
in the edge of the opening.
9. Method according to Claim 7, characterized in that
said step of taking-in the edge of the opening is
performed by means of eccentric rotation of the die-
cutting apparatus around the centre of the opening.
10. Method according to Claim 1, characterized in that
it comprises an additional step involving application
of a strip of material (E1) to the tubular element
upstream of the first operation involving die-cutting
of the bottom of the bag.
11. Method according to Claim 10, characterized in
that said strip of material is applied symmetrically
with respect to the line for cutting the bottom during
forming of the bag.
12. Method according to Claim 1, characterized in that
said strip of material is a label.

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13. Machine comprising at least one station (F) for
forming the bag (1) from a tubular element (101), at
least one station (R) for filling the bag with the
material (2) supplied from a supplying apparatus (200)
and at least one station (S) for sealing the mouth (1a)
of the bag, characterized in that it comprises a first
and a second die-cutting apparatus (500) for forming at
least one first opening (6b) in the zone of the bottom
(1b) and at least one second opening (6a) in the zone
of the mouth (1a) of the bag (1).
14. Machine according to Claim 13, characterized in
that said die-cutting apparatus (500) is arranged
upstream of the forming station (F).
15. Machine according to Claim 13, characterized in
that said first die-cutting apparatus (500) comprises
means (501,502) for positioning the tubular element
(101) in the longitudinal direction (X-X).
16. Machine according to Claim 15, characterized in
that said means (501) for positioning the tubular
element (101) consist of at least one pair of fixed
rollers (501) and a movable roller (502) for adjusting
centring of the tubular element with respect to the
apparatus for first die-cutting of the tubular element
(101).
17. Machine according to Claim 13, characterized in
that said first die-cutting apparatus performs first
successive openings (6b) at a predefined interaxial
distance.
18. Machine according to Claim 17, characterized in
that said interaxial distance of the first openings

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(6b) in the longitudinal direction is predetermined
depending on the length of the bag (1) in the same
longitudinal direction.
19. Machine according to Claim 13, characterized in
that said first die-cutting apparatus is controlled by
means (1000) for controlling and implementing the
automatic machine cycle.
20. Machine according to Claim 13, characterized in
that means (F10) for welding the bottom (1b) of the bag
are arranged in the forming station (F).
21. Machine according to Claim 20, characterized in
that said means (F10) for welding the bottom (1b) are
able to form two welding lines (5b) extending in a
direction substantially parallel to the transverse
direction (Y-Y) of the bag and spaced from each other
in the longitudinal direction (X-X) by a suitable
amount able to contain the opening (6b) for gripping
the bag.
22. Machine according to Claim 13, characterized in
that means (S10) for sealing the mouth (1a) of the bag
(1) are arranged in the sealing station (S).
23. Machine according to Claim 22, characterized in
that said means (S10) for welding the mouth (1a) of the
bag are able to form two welding lines (5a) extending
in a direction substantially parallel to the transverse
direction (Y-Y) of the bag and spaced from each other
in the longitudinal direction (X-X) by a suitable
amount able to contain a second opening (6a) for
gripping the bag (1).
24. Machine according to Claim 13, characterized in

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that said second die-cutting apparatus (500) is
arranged downstream of the sealing station (S).
25. Machine according to Claim 13, characterized in
that said second die-cutting apparatus (500) is able to
form openings (6a) in a strip of bag situated between
the two seals (5a) of the mouth of the said bag.
26. Machine according to Claim 13, characterized in
that said second die-cutting apparatus (500) is
controlled by means (1000) for controlling and
implementing the automatic machine cycle.
27. Machine according to Claim 13, characterized in
that said die-cutting apparatus (500) is of the hot
type.
28. Machine according to Claim 13, characterized in
that said die-cutting apparatus (500) is associated
with means able to impart an eccentric rotation of the
apparatus about the centre of the opening.
29. Machine according to Claim 13, characterized in
that it comprises an apparatus (E) for applying a layer
of material to the tubular element (101).
30. Machine according to Claim 29, characterized in
that it comprises an apparatus (E) for applying a layer
of material which is arranged upstream of the apparatus
(500) for first die-cutting the bottom of the bag.
31. Machine according to Claim 30, characterized in
that said apparatus (E) for applying a layer of
material is a labelling machine.
32. Bag filled with bulk material (2), characterized

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in that it comprises at least one first opening (6b)
arranged on the bottom (1b) of the bag and at least one
second opening (6a) arranged in the zone where the
mouth (1a) of the said bag is situated, each gripping
opening being delimited in the longitudinal direction
(X-X) of the bag by at least two welding lines (5b, 5a)
extending in a transverse direction (Y-Y) of the bag
and suitably spaced from each other in the longitudinal
direction (X-X) of the said bag.
33. Bag according to Claim 32, characterized in that
it is made by means of a method according to Claim 1.
34. Bag according to Claim 32, characterized in that
it is made by means of a machine according to Claim 13.
35. Bag according to Claim 32, characterized in that
said at least one first and second openings consist of
a hole.
36. Bag according to Claim 32, characterized in that
said at least one first and second openings consist of
an eyelet extending in the transverse direction (Y-Y).

Description

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METHOD AND MACHINE FOR FORMING GRIPPING ELEMENTS IN
BAGS FILLED WITH BULK MATERIAL
DESCRIPTION
The present invention relates to a method and a
machine for forming gripping elements in bags filled
with bulk material.
It is known in the goods sector relating to the
packaging of bulk material that there exists the need
to arrange the same inside bags which must be filled
with a given and certain quantity of material and then
sealed.
It is also known that automatic bag filling
machines have been provided for this purpose, an
example of said machines consisting of so-called
forming/filling/sealing (FFS) machines which are able
to perform, at high speed, the cycle involving forming
of the bag, filling of the bag and final sealing of the
mouth of the latter.
The resultant final product is a filled and sealed
bag which must be able to be handled with great ease
during the various subsequent transportation, storage
and distribution operations.
For this purpose, it is also known to form
holes/eyelets along one side of the bag, normally along
the side corresponding to the sealed mouth thereof,
such that they form the handle allowing gripping of the
bag by users.
Although fulfilling their function these bags
nevertheless have drawbacks arising from the fact that
the formation of said holes/eyelets involves
considerable technical difficulties during execution,
in particular in connection with said automatic
forming/filling machines, which are normally used in
the sector; in addition to this, there is also the need
to reinforce the side on which said hole/eyelet which

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during gripping of the bag must support the entire
weight of the bag is formed.
The technical problem which is posed, therefore,
is that of providing a bag which has gripping means
able to allow easy and safe manoeuvring during the
various handling steps.
Within the context of this problem a further
requirement is that the formation of said gripping
means should not involve the need to increase the
l0 strength and therefore the thickness of the material of
the entire bag, but if necessary only in the zone where
the said gripping means are formed, and may be
performed at high speed using an automatic machine
without reducing substantially the production speed.
These technical problems are solved by means of a
method according to the characteristic features of
Claim 1, a machine according to the characteristic
features of Claim 13 and a bag according to Claim 32.
Further details may be determined from the
following description of a non-limiting embodiment of
the subject of the present invention provided with
reference to the accompanying drawings, in which:
Figure 1 shows a schematic side view of a filling
machine with a die-cutting apparatus according to the
present invention;
Figure 2 shows a front view of a bag according to
the present invention;
Figure 3 shows an example of embodiment of a
machine according to the present invention; and
Figure 4 shows front views of the bag in the
various stations of the machine according to Fig. 3.
As schematically shown in Figure 1 and with
reference to two reference axes, conventionally and
only for the sake of convenience of the description
identified as the longitudinal axis X-X and transverse
axis Y-Y, a non-limiting illustrative example of a

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machine for filling bags 1 with bulk material 2 may be
of the forming/filling type which comprises
substantially at least three working stations,
respectively:
- a station F for forming the bag 1 from a tubular
element 101 unwound from a reel 101a; in this station
sealing of the bottom lb of the bag and cutting to size
of the tubular element resulting in formation of the
mouth la of the bag 1 is performed;
- a station R for filling the bag with the
material supplied from the filling apparatus (200);
- a station S for sealing the mouth la of the bag.
Transportation of the bag from one station to the
other is performed by means of a slide 110 provided
with gripping means 111, while conveying of the bag
outside of the machine is obtained by means of a motor-
driven belt or roller 113.
Fixed pairs of grippers 122 which have suitable
dimensions in order to support the weight of the bag
under full load are also arranged in the filling
station.
In a preferred embodiment of the FFS/filling
machine, which is conventional per se and therefore
neither illustrated nor described in detail, the said
bag transportation means consist of a slide 110 which
is displaced with an alternating outward and return
movement and provided with pairs of opposite grippers
for gripping the bag along the opposite vertical edges
thereof, said slide being able to impart to the
grippers movements in a direction transverse with
respect to that of feeding of the bag so as to cause
opening of its mouth during its travel from the forming
station F to the filling station R and closing thereof
during its travel from the station R to the sealing
station S.
According to the present invention it is envisaged

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that, upstream of the forming station E, an apparatus
500 for die-cutting the tubular element 101 is
arranged, said apparatus being activated in accordance
with a sequence controlled by the control means 1000 of
the machine so as to form at least one opening 6b at
constant intervals.
The interaxial distance of the openings 6b in the
longitudinal direction is determined depending on the
length of the bag 1 in the same direction.
As shown, the tubular element is supplied to the
die-cutting apparatus 500 by means of at least two
rollers 501 arranged on opposite sides with respect to
the said station and by a movable roller 502 for
adjusting centring of the tubular element depending on
the length of the bag envisaged so as to ensure the
correct position of the tubular element 101 during die-
cutting.
Once the said opening 6b has been formed, the
tubular element 101 is conveyed to the abovementioned
forming station F, where means F10 are provided for
performing a weld 5b on the bottom lb along two lines
substantially parallel to the transverse direction Y-Y
of the bag 1 and spaced from each other in the
longitudinal direction X-X by an amount suitable for
containing the opening 6b within two bag portions of
suitable length for ensuring the necessary breakage
resistance.
Once the formed bag 1 has been conveyed to the
filling station R - which is conventional per se and
therefore not described in detail - and filling
performed, the bag 1 is conveyed to the sealing station
where means S10 similar to those of the forming station
F perform sealing of the mouth la of the bag by means
of two welding lines 5a extending in a direction
substantially parallel to the transverse direction Y-Y
of the bag 1 and suitably spaced from each other in the

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longitudinal direction X-X.
Once the said double weld 5a has been performed,
the bag 1 is conveyed to a second die-cutting station
500 where the formation of at least one hole/eyelet 6a
along the side where the mouth la is situated and
inside a strip of material situated between the two
said welds 5a is performed so that the opening 6a is
comprised within and integral with two bag portions of
suitable length for ensuring the necessary breakage
resistance.
As shown in Fig. 2, the resultant product consists
of a bag 1 having gripping elements 6a,6b along both
the opposite transverse sides of the said bag which
make gripping thereof easy and safe, both for a single
user and for two users should the volume of the bag
result in large dimensions and considerable weight.
According to the invention it is also envisaged
providing a method for forming gripping means in bags,
which comprises the following steps:
a) supplying a tubular element lOla to a die-
cutting apparatus;
b) forming at least one opening 6b in a predefined
area;
c) supplying the tubular element 101 to a station
for forming a bag l;
d) providing at least two welding lines 5b along
the bottom zone lb of the bag 1 and on opposite sides
in the longitudinal direction X-X with respect to said
opening 6b;
e) transporting the bag 1 to the filling station R
and filling the bag;
f) feeding the bag S to a station S for closing
said bag;
g) providing at least two welding lines 5a,
substantially parallel to the transverse direction Y-Y
and at a suitable relative distance in the longitudinal

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direction X-X of the bag 1;
h) forming at least one opening 6a in the zone
comprised between the two welds 5a of the mouth la of
the bag.
According to preferred embodiments of the method
it is envisaged that the tubular element is supplied by
means of unwinding thereof from a reel lOla; that the
openings may be holes or eyelets extending in the
transverse direction; that the openings along the side
where the mouth la of the bag 1 is situated are formed
separately from the step for forming the welds for
closing the said bag.
It is also envisaged that the opening of the hole
may be hot-formed following a step involving taking-in
the edge of the said hole in order to provide a
perimetral bead integral with the material of the bag
and able to reinforce the gripping zone of the latter
without the addition of materials.
Preferably this taking-in operation is performed
by means of eccentric rotation of the hot die-cutting
means around the edge of the hole.
In the event of the bag being of considerable
weight, it is also envisaged being able to add
reinforcing material in the die-cutting zone; according
to preferred embodiments this material is in the form
of an adhesive strip E1 applied (Fig. 3) by means of a
machine of the labelling type arranged between the reel
lOla and the apparatus 500 for performing first die-
cutting of the bottom zone lb of the bag 1.
As shown in Fig. 4, the label is applied (Fig. 4a)
in a substantially symmetrical position (Fig. 4b) with
respect to the line for cutting the bottom lb of the
bag so as to leave an adhesive strip along the first
die-punched zone of the bottom (Fig. 4c) - formed
before entry of the tubular element 101 into the
filling machine - and an adhesive strip (Fig. 4d) along

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the second die-cutting zone of the mouth la of the bag
1, which will be performed when the bag 1 leaves the
same machine.

Representative Drawing