[0001] The subject of the present invention is a device and a relative cutting method for
the separation of bags for flexible packaging obtained from laminated films, for the
containment of food for humans, animal feed, etc.
[0002] The laminated films used for the formation of these bags also comprise at least one
layer of aluminium or in any case of materials that have a certain rigidity.
[0003] These laminated films are adequately shaped by folding and longitudinal sealing to
form a tubular shape, forming any side gussets, seals and transversal cuts to separate
the bags one from the other, or to cut the tubular shape to the length of the bag
to be formed.
[0004] In order to avoid that, once the bag has been shaped and then filled with the product,
the sharp corners of the bag itself during storage and transport will cut into the
bags close to it, piercing them, or worse, hurt the end user, during the shaping of
the bags the corners are rounded by means of a cutting die.
[0005] In practice, with reference to the accompanying Figure 1, which represents a consolidated
prior art, whereof the Applicant is not aware of any patents describing it, before
the operation of transversal cutting of the tubular shape to a length corresponding
to that of the bag to be obtained, cuts 2 are made on the tubular shape 1 in the shape
of a V with rounded edges.
[0006] Due to small inaccuracies during the film feed, it is extremely difficult to match
the transversal cut with the apex 3 of the previously performed V-shaped die-cutting
2. This means that a corner of the bag, upper or lower, is not perfectly rounded but
has a protuberance 6 (Figure 2) called "beak" which is dangerous because it is sharp
and therefore not acceptable for the above.
[0007] To avoid this inconvenience, the state of the art provides for a double cut with
a removal of about 2 mm of product as shown in Figure 3, in order to avoid the formation
of the beak 6.
[0008] This operation is normally carried out by making a first cut at the theoretical distance
of one millimetre from the apex 3 of the V-shaped die-cut 2. The film is advanced
by 2 mm from right to left with reference to Figures 1 to 3, and a second cut is made
by removing a portion of product 4 of 2 mm.
[0009] For obvious reasons, this double cutting operation leads to a slowdown in production
speed.
[0010] Incidentally, it should be noted that in the production of these bags, the film is
continuously advanced for the execution of certain operations, such as longitudinal
folding, and intermittently for the execution of other operations, such as precisely
the die-cutting and transversal cutting.
[0011] It is therefore clear that the advancement of the film between the two consecutive
cuts is down time in the production process, as it is not possible in the second cutting
operation to perform any other operation on the stationary film.
[0012] The Applicant has sought to solve this problem with European patent application
EP18172308.1, not yet published, which provides for a pair of blades placed side by side, distanced
one from the other, such as to be placed astride the apex of said V-shaped die-cuts
during said transversal cutting of laminated film.
[0013] The pair of blades is carried by a carriage that moves along a linear guide transversally
to the film in one direction and in the other, cutting the film at each single stroke.
The strip of material that is cut by the two blades is expelled by a blow of air.
[0014] This device, having two blades perfectly side by side, has highlighted two important
problems:
- If one of the two blades cuts the material a few tenths of a millimetre before the
other, in proximity of the final edge of the bag that is formed, the trimmed part
tends to bend and the second blade fails to cut. The waste remains therefore attached
to the bag for a few tenths of a millimetre of uncut material 4', as shown schematically
in Fig. 4.
- Even if the cut is made correctly, it can happen that the trimmed part is jammed between
the two blades, making it difficult to cut the next bags.
[0015] The object of the invention is to eliminate the drawbacks of the prior art illustrated
above, in particular those found in the device that is the subject of document
EP 18172308.1.
[0016] Therefore, the object of the invention is to improve the device and the method described
in document
EP 18172308.1, preventing the material waste from staying attached to the bag being formed, or
from getting caught between the cutting blades.
[0017] Another object of the invention is to provide a cutting device that is highly reliable
and avoids down time in the process of manufacturing flexible packaging bags.
[0018] These and other objects are achieved by the cutting device according to the invention,
which has the features of the appended independent claim 1.
[0019] Advantageous embodiments of the invention are disclosed in the dependent claims.
[0020] Substantially, the device according to the invention for the transversal cutting
of laminated films, at V-shaped die-cuts provided on that film at distances corresponding
to the length of bags to be produced, comprises at least two blades offset and spaced
apart one in relation to the other, such as to be placed astride an apex of said die-cuts
during said transversal cut, one of said blades acting against a side abutment to
make a scissors cut of the film.
[0021] According to an advantageous embodiment, the device for the transversal cutting of
laminated films according to the invention comprises three blades, two of these blades
being aligned one with the other, while the third blade is offset and spaced apart
with respect to them, such that the blades aligned on one side and the blade offset
on the other are placed astride an apex of said die-cuts during said transversal cut,
the blade offset and spaced apart being placed in an intermediate position with respect
to the aligned blades and acting against a side abutment to make a scissors cut of
the film.
[0022] Said blades are carried by a carriage moving along a linear guide placed transversally
to the film.
[0023] Said blades are mounted on respective supports that run along a channel determined
by two opposed fixed bars placed transversally to the film, and protrude below these
bars through a narrow opening of said channel.
[0024] Further features of the invention will be made clearer by the detailed description
that follows, referred to a purely illustrative and therefore non-limiting embodiment
of the invention, illustrated in the accompanying drawings, in which:
Figures 1, 2 and 3 are schematic plan views showing the successive phases during the
transversal cutting of a tubular film for the separation of bags with elimination
of the "beak" according to the prior art;
Figure 4 is a plan view substantially similar to the previous figures, showing a film
with advancement from right to left that is subjected to transversal cutting with
the device according to EP 18172308.1, highlighting a possible drawback illustrated above.
Figures 5 and 6 are schematic views in section taken in the direction of advancement
of the film, of the cutting device according to the invention, shown respectively
in rest and working position;
Figure 6a is an enlargement of the detail enclosed in circle A of Figure 6;
Figure 7 is a schematic partial view, with parts removed, taken from the right with
respect to Figure 5;
Figure 8 is a section taken along line A-A of Figure 7;
Figure 9 is a perspective view of the blade assembly.
[0025] Figure 4 shows schematically in plan view a film 1 in an intermediate stage of the
bag production process.
[0026] The film is unwound from a reel and initially fed continuously through a series of
stations, where it undergoes in particular a longitudinal folding to form a tubular
shape, and then intermittently to be subjected to operations that require the film
to be at a standstill.
[0027] In the plant or machine for the production of bags, which will not be described in
detail as not the subject of the invention, a device is provided for transforming
the advancement of the film from continuous to intermittent.
[0028] The film 1 shown in Figure 4 is downstream of such a device, and therefore undergoes
stops during the advancement in order to be subjected to the various operations to
be carried out on the stationary film, such as sealing, engraving, die-cutting, transversal
cutting and so on.
[0029] In the position of Figure 4, film 1, which is a laminate comprising at least one
layer of aluminium or in any case of a material with a certain rigidity, has been
folded longitudinally to form a tubular shape, and on it V-shaped die-cuts have been
made with rounded edges, at transversal lines 5 placed at a distance corresponding
to the length of the bag to be obtained.
[0030] As mentioned above, these die-cuts 2 are made to avoid that the bags produced have
sharp corners.
[0031] To avoid the formation of sharp corners, i.e. of the "beak" 6 (Figure 2), unlike
what occurred in the preceding prior art, which provided for two successive cuts to
remove a strip of material 4, as shown in Figures 1 to 3,
EP 18172308.1 proposed to remove this strip of material 4 in a single pass, by means of a pair
of blades side by side, which, however, in the case of a slight advance of one blade
with respect to the other during cutting, could determine the inconvenience shown
in Figure 4, i.e. the remainder of a small section of uncut material 4' with which
the strip 4 remained attached to the bag to be formed.
[0032] To solve the problems found in
EP 18172308.1, the invention proposes the cutting device shown in Figures 5 to 9, denoted overall
by reference numeral 10.
[0033] The device 10 comprises three blades 11, 12, 13, mounted on respective supports 41,
42, 43 (see in particular Figures 7 and 9), carried by a plate 20 in the shape of
an overturned L tilted through 180°, fixed to a second plate 21 in the shape of an
overturned L, in turn fixed to a carriage 22 sliding transversally on a linear guide
23 arranged transversally to the machine.
[0034] The plates 20, 21 and the carriage 22 form a whole so that here below these elements
will be identified also with the carriage 22 alone.
[0035] The carriage 22 is moved by a toothed belt 24 fixed to the upper plate 21 by means
of counter plates 25.
[0036] The toothed belt 24 is driven in reciprocal motion by means of a motor and corresponding
pinion not shown.
[0037] Naturally, carriage 22 can also be moved in another way, for example by means of
worm gears and screw nuts, pneumatic actuators, and the like.
[0038] The supports 41, 42, 43 of the blades 11, 12, 13 run along a channel 27 determined
by two opposed bars 30, 30 integral to the structure of the machine (Figures 5 and
6).
[0039] Channel 27 is open above to allow the insertion therein of the blade supports 41,
42, 43, and opens at the bottom as a funnel to allow the exit of the blades 11, 12,
13 that protrude slightly beyond the lower plane 31 of the bars 30.
[0040] In Figures 5 and 6, film 1 has been schematised with a dotted line and is moved intermittently
from left to right as indicated by the arrows F.
[0041] Below the bars 30 there are two pressers 32, movable from the bottom upwards and
vice versa as indicated by the double arrow F1 to move from a position distanced from
the bars 30, as shown in Figure 5, to allow the advancement of the film 1, to a position
of blocking of the film 1 against abutment stops 33 provided in the bars 30 during
the stop phase of the film, as shown in Figure 6.
[0042] In the embodiment shown in Figures 5 and 6, the pressers 32 are carried by an arm
(or rather two side arms) 50, oscillating around a fulcrum 51, which makes the pressers
perform a movement along an arc of circle, for the purposes that will be mentioned
here below.
[0043] According to the invention, the three blades 11, 12, 13 are arranged so that the
blades 11, 13 are perfectly aligned in the transversal direction of the machine, while
the blade 12 is slightly offset with respect thereto by a quota corresponding to the
width d of the strip 4 of material to be trimmed (normally 2-2.5 mm but could vary
by changing the distance between the blades), and spaced apart transversally, so as
to result in an intermediate position between the blades 11 and 13.
[0044] In this way, according to the direction of movement of carriage 22, the front blade
of the two aligned blades 11, 13 performs the cut, and the other one that follows
it remains inactive, while the offset intermediate blade 12 cuts the trimmed part
or strip of material 4 in both directions of movement of carriage 22.
[0045] In order to prevent the edge of the bag that is formed by the tubular film from bending
after the first cut made by blade 11 or 13 and thus preventing blade 12 from cutting,
blade 12 is made to slide in contact with a side abutment, thus cutting like scissors.
[0046] This side abutment is provided by one of the two 32 pressers (the one on the left
in Figures 5 and 6) which, during the cutting stroke of the blades, slightly touches
the blade 12 to allow the "scissors" trimming cut (see in particular the enlargement
of Figure 6a). The movement of pressers 32 around the fulcrum 51 of the arms 50 along
an arc of circle allows the corresponding stop 32 to approach blade 2 without interfering
with the tip of the blade itself.
[0047] This solution is optimal because it does not force the blades to perform the whole
stroke corresponding to the length of the bars 32 to come out from the same at each
transversal cut to allow the rise of the pressers 32 after the advancement of the
film, but it is possible to optimise the stroke of the blades, varying it according
to the width of the bag to be cut, being able to achieve higher production speeds.
[0048] If these advantages are to be relinquished, it would obviously be possible, in an
alternative solution, to have the assembly of blades coming out laterally with respect
to the mobile locking bars 32. In this case, the bars 32 could also move perfectly
vertically.
[0049] During cutting, the material waste 4 is evacuated between the two pressers 32 by
means of air nozzles 35 placed at the two sides of the blade assembly (Figure 7),
which blow downwards the trimmed part 4, which is collected by an underlying suction
hood (not shown).
[0050] After each transversal stroke of carriage 22, the blades 11, 12, 13 remain outside
the trajectory of the film 1, which can therefore be moved forward, as shown in Figure
5, then blocked by the pressers 32 in the next stop phase, as shown in Figure 6, and
be cut again transversally in the return stroke of carriage 22.
[0051] The fact that the blades 11, 13 and 12 are spaced apart also avoids the problem of
the jamming of the trimmed part 4 between the blades.
[0052] The supports 41, 43 of the side blades 11, 13 are fixed, while the support 42 of
the central blade 12 can be adjusted forwards and backwards by means of an adjustment
screw 45 (Figure 8). In this way, it is easy to adjust the interference between the
trimming blade 12 and the abutment plane of the corresponding mobile presser 32.
[0053] The advantages of the device according to the invention appear clear from the above,
which allows a safe detachment of the trimmed part 4 from the film 1, also preventing
it from getting caught between the blades.
[0054] In the accompanying drawings, the blades 11, 12, 13 have been indicated as double-edged,
i.e. with a V-shaped tip, in order to be able to cut in one direction and in the other.
However, the side blades 11, 13 could be single cut, as also the central blade 12
could be made up of two perfectly aligned opposed single-cutting blades.
[0055] According to an alternative embodiment of the invention, only one of the two lateral
blades 11, 13 can be provided, in which case the cut would only take place in one
direction of movement of the carriage, with an empty return stroke. In this case,
both blades could be single-cutting, unidirectional.
[0056] Naturally the invention is not limited to the particular embodiment previously described
and illustrated in the accompanying drawings, but numerous detailed changes may be
made thereto within the reach of the person skilled in the art, without thereby departing
from the scope of the invention itself, as defined by the appended claims.
1. Device for the transversal cutting of laminated films (1) at V-shaped die-cuts (2)
provided on said film at distances corresponding to the length of bags to be produced,
characterised in that said device (10) comprises at least two blades (11, 13) and (12) spaced apart and
offset from each other, such as to be arranged astride an apex (3) of said die-cuts
(2) during said transversal cut, one (12) of said blades acting against a side abutment
to make a scissors cut of the film (1).
2. Device for the transversal cutting of laminated films (1) according to claim 1, characterised in that it comprises three blades (11, 12, 13), two of said blades (11, 13) being aligned
with each other, while the third blade (12) is spaced apart and offset with respect
to them, such that the blades (11, 13) on one side and the blade (12) on the other
are arranged straddling an apex (3) of said die-cuts (2) during said transversal cutting,
the spaced apart and offset blade (12) being arranged in an intermediate position
with respect to the blades (11, 13) and acting against a side abutment to perform
a scissors cut of the film (1).
3. Cutting device according to claim 1 or 2, characterised in that said blades (11, 12, 13) are carried by a carriage (22) movable along a linear guide
(23) arranged transversally to said film (1).
4. Cutting device according to claim 3, characterised in that said blades (11, 12, 13) are mounted on respective supports (41, 42, 43) which run
along a channel (27) determined by two opposed fixed bars (30, 30) placed transversally
to the film (1), and protrude below these bars through a narrow opening of said channel
(27).
5. Cutting device according to claim 4, characterised in that it comprises a pair of pressers (32) placed below the bars (30, 30) and movable from
the bottom upwards and vice versa, to abut against rubber stops (31) provided in said
bars for locking the film (1) during the cutting step, one of said pressers acting
as side abutment for said blade (12).
6. Cutting device according to claim 5, characterised in that said pressers (32) move along an arc of a circle, or along a straight line vertically.
7. Cutting device according to any one of claims 4 to 6, characterised in that air nozzles (35) are arranged at the two sides of the blade assembly (11, 12, 13)
which blow on the scrap of material (4) to evacuate it through the lower opening of
said channel (27).
8. Cutting device according to any one of claims 4 to 6, characterised in that said supports (41, 43) of the blades (11, 13) are fixed, whereas the support (42)
of the blade (12) is adjustable by means of an adjustment screw (45).
9. Method for the transversal cutting of a laminated film (1) for the production of bags,
said film (1) having been previously subjected to V-shaped die-cuts (2) at distances
corresponding to the length of the bags to be produced, characterised in that a double cut is provided, performed simultaneously with two blades (11, 13) and (12)
spaced apart and offset from each other, which are arranged astride the apices (3)
of said V-shaped die-cut (2), and slide transversally to the film (1), one (12) of
said blades sliding in contact with a side abutment to perform a scissors cut of the
film (1).
10. Method according to claim 9, wherein three blades (11, 12, 13) are provided, which
run in the two directions transversally to the film (1), two of said blades (11, 13)
being aligned with each other, while the third blade (12) is spaced apart and offset
with respect to them, being arranged in an intermediate position with respect to the
blades (11, 13), such that according to the direction of movement of the blades, the
forward one of the two aligned blades (11, 13) makes the cut, and the other one that
follows it remains inactive, while the spaced apart intermediate blade (12) cuts the
trimmed part or strip of material (4) in both directions of movement of the blades
sliding in contact with a side abutment to make a scissors cut of the film (1).
1. Vorrichtung zum Querschneiden von Verbundfolien (1) an V-förmigen Stanzungen (2),
die auf der Folie in Abständen entsprechend der Länge der herzustellenden Beutel vorgesehen
sind, dadurch gekennzeichnet, dass die Vorrichtung (10) mindestens zwei Klingen (11, 13) und (12) umfasst, die mit Abstand
angeordnet und gegeneinander versetzt sind, sodass sie während des Querschneidens
über einen Scheitel (3) der Stanzungen (2) hinweg angeordnet sind, wobei eine (12)
der Klingen gegen einen seitlichen Anschlag wirkt, um einen Scherenschnitt der Folie
(1) durchzuführen.
2. Vorrichtung zum Querschneiden von Verbundfolien (1) nach Anspruch 1, dadurch gekennzeichnet, dass sie drei Klingen (11, 12, 13) umfasst, wobei zwei der Klingen (11, 13) zueinander
ausgerichtet sind, während die dritte Klinge (12) mit Abstand und versetzt zu ihnen
angeordnet ist, sodass die Klingen (11, 13) auf einer Seite und die Klinge (12) auf
der anderen Seite während des Querschneidens angeordnet sind, wobei sie einen Scheitelpunkt
(3) der Stanzungen (2) überspannen, wobei die mit Abstand angeordnete und versetzte
Klinge (12) in einer Zwischenposition in Bezug auf die Klingen (11, 13) angeordnet
ist und gegen einen seitlichen Anschlag wirkt, um einen Scherenschnitt des Films (1)
durchzuführen.
3. Vorrichtung zum Schneiden nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass die Klingen (11, 12, 13) von einem Schlitten (22) getragen werden, der entlang einer
quer zur Folie (1) ausgelegten Linearführung (23) beweglich ist.
4. Vorrichtung zum Schneiden nach Anspruch 3, dadurch gekennzeichnet, dass die Klingen (11, 12, 13) auf entsprechenden Trägern (41, 42, 43) montiert sind, die
entlang eines Kanals (27) laufen, der durch zwei gegenüberliegende feste Stangen (30,
30) bestimmt ist, die quer zur Folie (1) angeordnet sind, und unter diesen Stangen
durch eine enge Öffnung des Kanals (27) vorstehen.
5. Vorrichtung zum Schneiden nach Anspruch 4, dadurch gekennzeichnet, dass sie ein Paar von Pressvorrichtungen (32) umfasst, die unter den Stangen (30, 30)
angeordnet und von unten nach oben und umgekehrt beweglich sind, um gegen Gummianschläge
(31) zu stoßen, die in den Stangen vorgesehen sind, um die Folie (1) während des Schneideschritts
zu fixieren, wobei eine der Pressvorrichtungen als Seitenanschlag für die Klinge (12)
dient.
6. Vorrichtung zum Schneiden nach Anspruch 5, dadurch gekennzeichnet, dass die genannten Pressvorrichtungen (32) sich entlang eines Kreisbogens oder vertikal
entlang einer geraden Linie bewegen.
7. Vorrichtung zum Schneiden nach einem der Ansprüche 4 bis 6, dadurch gekennzeichnet, dass an den beiden Seiten der Klingenanordnung (11, 12, 13) Luftdüsen (35) vorgesehen
sind, die auf den Materialabfall (4) blasen, um ihn durch die untere Öffnung des genannten
Kanals (27) abzusaugen.
8. Vorrichtung zum Schneiden nach einem der Ansprüche 4 bis 6, dadurch gekennzeichnet, dass die Halterungen (41, 43) der Klingen (11, 13) fest sind, während die Halterung (42)
der Klinge (12) mittels einer Einstellschraube (45) einstellbar ist.
9. Verfahren zum transversalen Schneiden einer laminierten Folie (1) für die Herstellung
von Beuteln, wobei die Folie (1) zuvor V-förmigen Stanzungen (2) in Abständen, die
der Länge der herzustellenden Beutel entsprechen, unterzogen wurde, dadurch gekennzeichnet, dass ein Doppelschnitt vorgesehen ist, der gleichzeitig mit zwei Klingen (11, 13) und
(12) durchgeführt wird, die voneinander mit Abstand und versetzt zueinander angeordnet
sind, die auf den Scheitelpunkten (3) der V-förmigen Stanzung (2) rittlings aufliegen
und quer zum Film (1) gleiten, wobei eine (12) der Klingen in Kontakt mit einem seitlichen
Anschlag gleitet, um einen Scherenschnitt des Films (1) durchzuführen.
10. Verfahren nach Anspruch 9, bei dem drei Klingen (11, 12, 13) vorgesehen sind, die
in den beiden Richtungen quer zur Folie (1) laufen, wobei zwei der Klingen (11, 13)
zueinander ausgerichtet sind, während die dritte Klinge (12) mit Abstand und versetzt
zu ihnen in einer Zwischenposition in Bezug auf die Klingen (11, 13) angeordnet ist,
sodass gemäß der Bewegungsrichtung der Klingen die vordere der beiden ausgerichteten
Klingen (11, 13) den Schnitt ausführt und die andere, die ihm folgt, inaktiv bleibt,
während die mit Abstand angeordnete Zwischenklinge (12) den beschnittenen Teil oder
Streifen des Materials (4) in beiden Bewegungsrichtungen der Klingen schneidet, die
in Kontakt mit einem seitlichen Anschlag gleiten, um einen Scherenschnitt der Folie
(1) auszuführen.
1. Dispositif destiné à la coupe transversale de films stratifiés (1) au niveau de découpes
à l'emporte-pièce en forme de V (2) munies sur ledit film à des distances correspondant
à la longueur de sacs devant être produits, caractérisé en ce que ledit dispositif (10) comprend au moins deux lames (11, 13) et (12) espacées l'une
de l'autre et en décalage l'une par rapport à l'autre, de manière à être agencées
en califourchon sur un sommet (3) desdites découpes à l'emporte-pièce (2) pendant
ladite coupe transversale, une (12) desdites lames agissant contre une butée latérale
afin de procéder à une taille en ciseaux du film (1).
2. Dispositif destiné à la coupe transversale de films stratifiés (1) selon la revendication
1, caractérisé en ce qu'il comprend trois lames (11, 12, 13), deux desdites lames (11, 13) étant alignées
l'une avec l'autre, tandis que la troisième lame (12) est espacée et en décalage par
rapport aux autres, de sorte que les lames (11, 13) situées sur un côté et la lame
(12) située sur l'autre côté sont disposées à cheval sur un sommet (3) desdites découpes
à l'emporte-pièce (2) pendant ladite coupe transversale, la lame espacée et en décalage
(12) étant agencée dans une position intermédiaire par rapport aux lames (11, 13)
et agissant contre une butée latérale afin d'effectuer une taille en ciseaux du film
(1).
3. Dispositif de coupe selon la revendication 1 ou la revendication 2, caractérisé en ce que lesdites lames (11, 12, 13) sont transportées au moyen d'un support (22) déplaçable
le long d'un guide linéaire (23) agencé de manière transversale par rapport audit
film (1).
4. Dispositif de coupe selon la revendication 3, caractérisé en ce que lesdites lames (11, 12, 13) sont montées sur des supports respectifs (41, 42, 43)
qui s'étendent le long d'un canal (27) déterminé par deux barres fixes opposées (30,
30) placées de manière transversale par rapport au film (1), et qui font saillie en
dessous de ces barres par l'intermédiaire d'une ouverture étroite dudit canal (27).
5. Dispositif de coupe selon la revendication 4, caractérisé en ce qu'il comprend une paire de presseurs (32) placés en dessous des barres (30, 30) et déplaçables
depuis la partie inférieure vers le haut et vice versa, pour venir buter contre des
butoirs en caoutchouc (31) montés dans lesdites barres destinées au verrouillage du
film (1) pendant l'étape de découpe, un desdits presseurs agissant en tant que butée
latérale pour ladite lame (12).
6. Dispositif de coupe selon la revendication 5, caractérisé en ce que lesdits presseurs (32) se déplacent le long d'un arc de cercle, ou le long d'une
ligne droite de manière verticale.
7. Dispositif de coupe selon l'une quelconque des revendications 4 à 6, caractérisé en ce que des buses d'air (35) sont agencées au niveau des deux côtés de l'ensemble de lame
(11, 12, 13) qui soufflent sur les débris de matière (4) afin de les évacuer par l'intermédiaire
de l'ouverture inférieure du canal (27).
8. Dispositif de coupe selon l'une quelconque des revendications 4 à 6, caractérisé en ce que lesdits supports (41, 43) des lames (11, 13) sont fixes, tandis que le support (42)
de la lame (12) est réglable au moyen d'une vis de réglage (45).
9. Procédé de découpe transversale d'un film stratifié (1) destiné à la production de
sacs, ledit film (1) ayant été précédemment soumis à des découpes à l'emporte-pièce
en forme de V (2) à des distances correspondant à la longueur des sacs devant être
produits, caractérisé en ce qu'une double coupe est effectuée, réalisée de manière simultanée à l'aide de deux lames
(11, 13) et (12) espacées l'une de l'autre et en décalage l'une par rapport à l'autre,
qui sont disposées à califourchon sur les sommets (3) de ladite découpe à l'emporte-pièce
en forme de V (2), et glissent de manière transversale par rapport au film (1), une
(12) desdites lames glissant en contact avec une butée latérale afin d'effectuer une
taille en ciseaux du film (1).
10. Procédé selon la revendication 9, dans lequel trois lames (11, 12, 13) sont fournies,
qui s'étendent dans deux directions de manière transversale par rapport au film (1),
deux desdites lames (11, 13) étant alignées l'une par rapport à l'autre, tandis que
la troisième lame (12) est espacée et en décalage par rapport aux autres, étant agencée
dans une position intermédiaire par rapport aux lames (11, 13), de telle sorte qu'en
fonction du sens de déplacement des lames, celle en avant parmi les deux lames alignées
(11, 13) réalise la découpe, et l'autre qui la suit reste inactive, tandis que la
lame intermédiaire espacée (12) coupe la partie découpée ou la bande de matériau (4)
dans les deux sens de mouvement des lames glissant en contact avec une butée latérale
afin de réaliser une taille en ciseaux du film (1).