FIELD OF THE ART
[0001] The present invention relates to an incision unit for a packaging machine for single-dose
break-open packages.
PRIOR ART
[0002] A sealed single-dose break-open package normally consists of a sheet made of a semirigid
plastic material and of a sheet made of a flexible plastic material arranged on top
of and sealed to each other in order to define a sealed pocket containing a dose of
product; the semirigid plastic material sheet centrally has an incision which guides
a controlled breaking of the semirigid plastic material sheet. In use, in order to
open the package, a user simply needs to grip the package itself with his/her fingers
and bend the package until the semirigid plastic material sheet breaks at the incision.
[0003] Patent application
WO2008038074A1 suggests a packaging machine which manufactures sealed single-dose break-open packages.
In such a packaging machine, a strip made of a semirigid plastic material and a strip
made of a flexible plastic material are unwound from respective reels and fed to a
forming station. A pattern is printed on the outer surface of the semirigid plastic
material strip and an incision is cut into the semirigid plastic material strip upstream
of the forming station; in particular, two incisions are cut at different times (i.e.
not simultaneously) into the opposite surfaces of the semirigid plastic material strip,
which incisions are opposite and aligned by means of two incision devices arranged
one next to the other in the conveying direction of the semirigid plastic material
strip. After that, the semirigid plastic material strip and the flexible plastic material
strip are arranged on top of each other in the forming station and then sealed in
a longitudinal sealing station in order to define a tube adapted to contain the product.
A dosing device is arranged at the longitudinal sealing station to feed the product
between the two strips which were longitudinally sealed. A transversal sealing station
is arranged downstream of the longitudinal sealing station to perform a transversal
sealing so as to close the pocket of each sealed single-dose package. Finally, a cutting
station is arranged downstream of the transversal sealing station, where the two strips
are cut transversely so as to separate, in sequence, the sealed single-dose packages.
[0004] However, it has been noted that, when operating at high speed in the above-described
packaging machine, the incision of the semirigid plastic material strip not always
has an optimal quality (in particular, the two incisions cut into the opposite surfaces
of the semirigid plastic material strip are not always perfectly aligned to each other).
DESCRIPTION OF THE INVENTION
[0005] It is the object of the present invention to provide for an incision unit for a packaging
machine which manufactures a single-dose break-open package, which incision unit is
free from the above-described drawbacks, and in particular is easy and cost-effective
to be implemented.
[0006] According to the present invention, an incision unit to manufacture a single-dose
break-open package is provided as defined in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The present invention will now be described with reference to the accompanying drawings,
which show a non-limiting embodiment thereof, in which:
- figure 1 shows a top perspective view of a sealed single-dose break-open package;
- figure 2 shows a bottom perspective view of the package in figure 1;
- figure 3 shows a cross-section of a semirigid plastic material sheet of the package
in figure 1;
- figure 4 shows a diagrammatic perspective view, with parts removed for clarity, of
a packaging machine manufactured according to the present invention for producing
the package in figure 1;
- figures 5-8 are four diagrammatic top views, with parts removed for clarity, of an
incision unit of the packaging machine in figure 4 during four different operation
moments;
- figure 9 is a diagrammatic section view, with parts removed for clarity, of a printing
unit of the packaging machine in figure 4; and
- figure 10 is a diagrammatic perspective view, with parts removed for clarity, of a
dosing unit of the packaging machine in figure 4.
PREFERRED EMBODIMENTS OF THE INVENTION
[0008] In figures 1 and 2, reference numeral 1 indicates as a whole a sealed single-dose
break-open package. Package 1 comprises a sheet 2 made of a semirigid plastic material
and rectangular in shape, and a sheet 3 made of a flexible plastic material, which
is arranged on top of and sealed to the semirigid plastic material sheet 2 in order
to define a sealed pocket 4 containing a dose of a fluid product 5. By way of example,
the fluid product 5 could be a sanitizing gel.
[0009] The semirigid plastic material sheet 2 centrally has a pre-weakened zone 6 which
guides a controlled breakage of sheet 2 so as to determine the formation of an outlet
opening for product 5 through sheet 2. In other words, in use, in order to open package
1 a user needs to grip package 1 with his/her fingers and bend package 1 until the
semirigid plastic material sheet 2 breaks at the pre-weakened zone 6.
[0010] As shown in figure 3, the pre-weakened zone 6 comprises an internal incision 7 which
is cut through an inner surface 8 (i.e. facing pocket 4) of the semirigid plastic
material sheet 2 and an outer incision 9 which is cut through an outer surface 10
of the semirigid plastic material sheet 2. According to a preferred embodiment, each
incision 7 or 9 is of variable depth along its length so as to determine a progressive
breaking of the semirigid plastic material sheet 2; in particular, each incision 7
or 9 has a maximum depth at a central portion.
[0011] In figure 4, reference numeral 11 indicates as a whole a packaging machine to produce
sealed single-dose packages 1 similar to that described above and shown in figures
1 and 2. The packaging machine 11 shown in figure 4 produces three sealed packages
1 at a time, i.e. operates in parallel on three adjacent tracks to produce three sealed
packages 1 at a time; according to other variants (not shown), the packaging machine
11 could obviously operate in parallel on a different number of tracks arranged one
next to the other (e.g. two, four, six tracks but also a single track).
[0012] The packaging machine 11 (shown in figure 4) comprises a frame (not shown) resting
on the floor by means of a plurality of resting feet (not shown) and supports a pair
of unwinding devices 12 and 13. The unwinding device 12 supports a reel 14 from which
it progressively unwinds a strip 15 of semirigid (yet elastically deformable) plastic
material which is fed to a forming station 16, and the unwinding device 13 supports
a reel 17 from which it progressively unwinds a strip 18 made of a flexible plastic
material which is also fed to the forming station 16.
[0013] A printing unit 19 is arranged between the unwinding device 12 of the semirigid plastic
material strip 15 and the forming station 16, where the outer surface 10 of the semirigid
plastic material sheet 2 is printed.
[0014] An incision unit 20 is arranged downstream of the printing unit 19 and upstream of
the forming station 16, and transversely cuts the semirigid plastic material strip
15 in order to define the incisions 7 and 9 at the pre-weakened zone 6 along the semirigid
plastic material strip 15.
[0015] According to a preferred embodiment, the semirigid plastic material strip 15 is continuously
fed through the incision unit 20; to this end, the incision unit 20 comprises a conveying
device 21 provided with a pair of feeding dandy rollers 22. The feeding dandy rollers
22 are movable against the action of elastic means to allow the semirigid plastic
material strip 15 to temporarily stop inside the incision unit 20.
[0016] As shown in figure 4, the semirigid plastic material strip 15 provided with the incisions
7 and 9 is then fed to the forming station 16, which is arranged downstream of the
incision unit 20 and where the semirigid plastic material strip 15 is arranged on
top of and sealed to the flexible plastic material strip 18.
[0017] The two strips 15 and 18 arranged one on top of the other are sealed to each other
by means of a longitudinal roller sealing device 23 which performs a longitudinal
sealing (both laterally and centrally), i.e. parallel to a conveying direction, so
as to define a plurality of tubes arranged one next to the other. In the embodiment
shown in figure 4, the longitudinal sealing device 23 comprises two twin sealing assemblies
arranged one on top of the other, each of which has a contrast roller 24 and four
sealing rollers 25 which are electrically heated and spaced apart from one another.
[0018] A dosing unit 26 to feed a dose of product 5 into each tube between the semirigid
plastic material strip 15 and the flexible plastic material strip 18 is arranged in
the forming station 16 and at the longitudinal sealing device 23. The dosing unit
26 comprises three twin feeding ducts 27, each of which is vertically arranged between
two sealing rollers 25 of the longitudinal sealing device 23 and feeds the doses of
product 5 between the semirigid plastic material strip 15 and the flexible plastic
material strip 18.
[0019] Finally, the forming station 16 comprises a transversal roller sealing device 28,
which is arranged downstream of the longitudinal sealing device 23 and transversely
seals together the two strips 15 and 18 in order to define a series of pockets 4 (shown
in figure 1) along each tube, each of which contains a dose of product 5. According
to a preferred embodiment, the transversal sealing device 28 comprises a contrast
roller 29 and a sealing roller 30, which is electrically heated and cooperates with
the contrast roller 29.
[0020] Finally, a cutting device 31 is arranged downstream of the forming station 16 so
as to cut transversely the strips 15 and 18 arranged one on top of the other and sealed
so as to separate in sequence the sealed single-dose packages 1. An outlet conveyor
belt 32 is arranged under the cutting device 31, on which the sealed single-dose packages
1 fall by gravity once they have been separated from the strips 15 and 18 arranged
on top of and sealed to each other.
[0021] The flexible plastic material strip 18 is normally pre-printed, whereas, as previously
said, the semirigid plastic material strip 15 is printed inside the packaging machine
11 by using the printing unit 19; according to an alternative embodiment, the printing
unit 19 is not present (or is disabled), therefore the semirigid plastic material
strip 15 is also pre-printed (or without prints). The flexible plastic material strips
15 and/or 18 are generally provided with reference notches, which are read by special
optical sensors to synchronize the several operations appropriately, so that the printed
zones are correctly centered in the finished sealed single-dose packages 1. The reference
notches are preferably printed in the zones of strips 15 and/or 18 which are discarded
by the cutting device 31 so as not to be present in the finished sealed single-dose
packages 1.
[0022] As shown in figure 9, the printing unit 19 of the semirigid plastic material strip
15 comprises a conveying device 33 (diagrammatically shown) which feeds the semirigid
plastic material strip 15 along a (substantially vertical) conveying direction C,
and a printing device 34 arranged in a fixed position along the conveying device 33
and facing the outer surface 10 of the semirigid plastic material strip 15 so as to
print a pattern on the strip 15 itself. The printing device 34 is a heat transfer
printing device and comprises a printing head 35, which is movable perpendicularly
to the conveying direction C along a printing direction S so as to contact the semirigid
plastic material strip 15; in other words, in use, the printing head 35 is movable
along the printing direction S, which is orthogonal to the conveying direction C and
orthogonal to the semirigid plastic material strip 15 so as to come into contact with
the outer surface 10 of the semirigid plastic material strip 15. Therefore, in use,
the printing head 35 contacts the semirigid plastic material strip 15 with a given
pressure so as to print a pattern on the semirigid plastic material strip 15.
[0023] The printing device 34 further comprises a fixed contrast plate 36 (i.e. in a fixed
position), which is independent and separate from the conveying device 33, is arranged
in a fixed position along the conveying device 33, and is arranged parallel to and
facing the printing device 34 so that the semirigid plastic material strip 15 is arranged
between the contrast plate 36 and the printing device 34. When the printing head 35
moves towards the semirigid plastic material strip 15, the printing head 35 presses
the semirigid plastic material strip 15 against the contrast plate 36 and therefore
the printing head 35 may exert a given pressure on the outer surface 10 of the semirigid
plastic material strip 15, which pressure is required to carry out the printing process
properly.
[0024] The contrast plate 36 comprises a plurality of nozzles 37, each of which opens up
onto the semirigid plastic material strip 15 and is adapted to release a compressed
air blow. In particular, each nozzle 37 consists of a through hole, which is obtained
through the contrast plate 36 and receives the compressed air by means of a pipe 39
connected to a compressed air source 40. The compressed air blown by the nozzles 37
creates a pressurized air cushion 38 at the inner surface 8 of the semirigid plastic
material strip 15, which inner surface 8 is opposite to the outer surface 10 and thus
opposite to the printing device 34. The air cushion 38 thus made creates a deformable
contrast which allows the printing head 35 to create a constant and even pressure
against the outer surface 10 of the semirigid plastic material strip 15; in other
words, the air cushion 38 is deformed in a variable and dynamic manner so as to adapt
perfectly to the shape of the printing head 35, thus ensuring a completely even contact
between the printing head 35 and the outer surface 10 of the semirigid plastic material
strip 15. In summary, the contrast plate 36 comprises a plurality of nozzles 37, which
open up onto the inner surface 8 of the semirigid plastic material strip 15 and are
adapted to release a compressed air blow to create the pressurized air cushion 38
at the inner surface 8 of the semirigid plastic material strip 15, opposite to the
printing device 34; the air cushion 38 forms a deformable contrast against which the
printing head 35 pushes the semirigid plastic material strip 15. Thereby, the printing
head 35 may operate under the most favorable conditions allowing a high quality pattern
to be obtained in very short times (i.e. also when the packaging machine 11 operates
at high speed).
[0025] According to a preferred embodiment, in order to maximize the effectiveness of the
contrasting action of the air cushion 38, the compressed air is fed to the nozzles
37 with a pressure from 2 to 6 bar (preferably from 3 to 5 bar).
[0026] According to an alternative embodiment (not shown), the printing device 34 may use
a printing technology other than heat transfer (e.g. it might use ink-jet); in this
case, the printing head 35 is fixed (i.e. does not translate perpendicularly to the
semirigid plastic material strip 15).
[0027] As shown in figure 4, the incision unit 20 cooperates with the conveying device 21
which feeds the semirigid plastic material strip 15 along the conveying direction
C. The incision unit 20 comprises two support plates 41, which are arranged along
the conveying device 21 downstream of the feeding dandy rollers 22 so that the feeding
dandy rollers 22 cyclically allow the semirigid plastic material strip 15 to temporarily
stop between the two support plates 41. The two support plates 41 are arranged on
opposite sides of the semirigid plastic material strip 15; therefore, each support
plate 41 faces a corresponding surface 8 or 10 of the semirigid plastic material strip
15.
[0028] As shown in figures 5-8, the incision unit 20 is provided with six incision devices
42, each of which cuts an incision 7 or 9 (shown in figure 3) into a corresponding
surface 8 or 10 of the semirigid plastic material strip 15; in particular, three incision
devices 42a, which are arranged one next to the other, cut respective inner incisions
7 into the inner surface 8 of the semirigid plastic material strip 15 and three incision
devices 42b, which are arranged one next to the other, cut respective outer incisions
9 into the outer surface 10 of the semirigid plastic material strip 15. Each incision
device 42 comprises a cutting element 43 supported by a support plate 41 and facing
the corresponding surface 7 or 9 of the semirigid plastic material strip 15, and a
contrasting element 44 supported by the other support plate 41 and facing the corresponding
surface 9 or 7 of the semirigid plastic material strip 15. Each cutting element 43
is provided with a blade (not shown in detail) which is preferably V-shaped; in contrast,
each contrast element 44 is flat so as to provide the blade of the corresponding cutting
element 43 with an even contrast.
[0029] The two support plates 41 are mechanically connected together so as to move synchronously
along a translation direction T which is orthogonal to the conveying direction C;
in particular, the two support plates 41 are mounted so as to be movable on corresponding
rails 45 so as to translate (slide) together along the translation direction T, which
is orthogonal to the conveying direction C. In other words, the two support plates
41 are provided with corresponding slides, which are slidingly coupled to the rails
45 so as to translate (slide) along the translation direction T under the control
of an actuating device 46 (e.g. of the electric or pneumatic type). The six incision
devices 42 are arranged one next to the other and are aligned along the translation
direction T. The actuating device 46 cyclically moves the two support plates 41 forward
and backward along the translation direction T between a first position (shown in
figures 5 and 6), in which the incision devices 41a cut the inner incisions 7 into
the inner surface 8 of the semirigid plastic material strip 15, and a second position
(shown in figures 7 and 8), in which the incision devices 41b cut the outer incisions
9 into the outer surface 10 of the semirigid plastic material strip 15.
[0030] Each support plate 41 supports the cutting elements 43 of an incision device 42a
or 42b and the contrast elements 44 of the other incision device 42b or 42a; in other
words, each support plate 41 supports both three cutting elements 43 and three contrast
elements 44.
[0031] A support plate 41 is movably mounted on corresponding rails 47 so as to translate
(slide) cyclically forward and backward towards the other support plate 41 and along
an incision direction I, which is orthogonal to both the conveying direction C and
the translation direction T. In other words, a support plate 41 is provided with corresponding
slides which are slidingly coupled to the rails 47 so as to translate (slide) along
the incision direction I under the control of an actuating device 48 (e.g. of the
electric or pneumatic type).
[0032] In a preferred embodiment shown in the accompanying figures, each incision device
42 comprises an adjusting organ 49 (e.g. a micrometer) to adjust the depth of incision
7 or 9 by varying the relative position between the corresponding cutting element
43 or the corresponding contrast element 44 and the respective support plate 41. Each
adjusting organ 49 is coupled to the cutting element 43 or to the contrast element
44 of the same incision device 42 and is adapted to adjust the distance between the
cutting element 43 or the contrast element 44 and the semirigid plastic material strip
15.
[0033] In a preferred embodiment shown in the accompanying figures, the adjusting organs
49 are all arranged on the same support plate 41 so as to facilitate the access by
an operator to the adjusting organs 49; in other words, if all the adjusting organs
49 are arranged on the same support plate 41, it is sufficient to allow an operator
to access said support plate 41 in order to act on all the adjusting organs 49.
[0034] The operation of the incision unit 20 is described below with reference to figures
5-8.
[0035] Firstly, the semirigid plastic material strip 15 is arranged at the incision devices
42a (figure 5), i.e. is arranged between the incision devices 42a. At this point and
as shown in figure 6, the two support plates 41 are approached each other by operating
actuator 48, which translates a support plate 41 along the rails 47 and in the incision
direction I; such a relative movement between the two support plates 41 leads the
incision devices 42a to cut the inner surface 8 of the semirigid plastic material
strip 15 (by approaching together the corresponding cutting elements 43 and contrast
elements 44) so as to cut the inner incisions 7 (the incision devices 42b also perform
an incision movement, although without practical effects since the semirigid plastic
material strip 15 is not present between the incision devices 42b).
[0036] Once the cutting of the inner incisions 7 into the inner surface 8 of the semirigid
plastic material strip 15 has been completed, the support plates 41 are brought back
to their initial distance (figure 5); the two support plates 41 are then translated
together by operating actuator 46 so as to move the two support plates 41 laterally
in the translation direction T in order to invert the incision devices 42 coupled
to the semirigid plastic material strip 15. In other words, firstly the incision devices
42a are coupled to the semirigid plastic material strip 15 (figure 5), whereas at
the end of the lateral translation of the two support plates 41, the incision devices
42b are coupled to the semirigid plastic material strip 15 (figure 7).
[0037] At this point and as shown in figure 8, the two support plates 41 are approached
each other by operating actuator 48, which translates a support plate 41 along the
rails 47 and in the incision direction I; such a relative movement between the two
support plates 41 leads the incision devices 42b to cut the outer surface 10 of the
semirigid plastic material strip 15 (by approaching together the corresponding cutting
elements 43 and contrast elements 44) so as to cut the outer incisions 9 (the incision
devices 42a also perform an incision movement, although without practical effects
since the semirigid plastic material strip 15 is not present between the incision
devices 42a).
[0038] Once the cutting of the outer incisions 9 into the outer surface 10 of the semirigid
plastic material strip 15 has been completed, the cycle of the incision unit 20 is
completed and the semirigid plastic material strip 15 is fed from the conveying device
21 along the conveying direction C.
[0039] The semirigid plastic material strip 15 does not move (i.e. is stationary in the
same position) between the cutting of the inner incisions 7 into the inner surface
8 of the semirigid plastic material strip 15 and the cutting of the outer incisions
9 into the outer surface 10 of the semirigid plastic material strip 15, since the
incision devices 42 supported by the two support plates 41 perform a lateral translation;
thereby, the incisions 7 and 9 have an almost perfect alignment with respect to each
other since it is totally free from possible errors due to the incorrect positioning
of the semirigid plastic material strip 15.
[0040] As shown in figure 10, the dosing unit 26 comprises a tank 50 holding the fluid product
5 and three feeding ducts 27, each of which originating from tank 50 and ending with
a delivery mouth 51 which is arranged at the longitudinal sealing device 23. A pump
52 is arranged along each feeding duct 27 so as to feed the fluid product 5 from tank
50 towards the delivery mouth 51.
[0041] Each pump 52 is a volumetric pump of peristaltic type (i.e. is a peristaltic pump)
so as to provide for a precise dosing of product 5. According to a preferred embodiment,
each peristaltic pump 52 has an impeller which supports a plurality of thrust elements
(not less than four thrust elements and preferably eight thrust elements).
[0042] According to a preferred embodiment, tank 50 is pressurized at a pressure which is
higher than the atmospheric pressure; such a feature allows the suction of product
5 by the peristaltic pumps 52 to be enhanced thus avoiding the occurrence of "voids"
along the feeding ducts 27 and increasing the precision of dosing product 5. In particular,
tank 50 has at least one nozzle 53, which is arranged in an upper portion of tank
50 and is adapted to blow a compressed air jet into tank 50, which keeps the internal
volume of tank 50 under pressure (i.e. pressurized).
[0043] According to a preferred embodiment, a shutoff valve 54 is included, which is arranged
along each feeding duct 27 upstream of the corresponding peristaltic pump 52. The
shutoff valves 54 allow the flow of product 5 along the feeding ducts 27 to be stopped
when the packaging machine 11 is stopped (with the packaging machine 11 stopped and
in the absence of the shutoff valves 54, a small amount of product 5 would continue
to flow by gravity along the feeding ducts 27).
[0044] The dosing unit 26 allows the fluid product 5 (in particular a sanitizing gel) to
be dosed with high precision (of the order of ±2-3%) even in the case of very small
amounts (e.g. of the order of one millimeter of fluid product in each single-dose
package 1). Such a result is also achieved,
inter alia, by using peristaltic pumps 52 which maintain a high precision even in the case of
low volumetric capacity.
[0045] The above-described packaging machine 11 has three production lines arranged one
next to the other and operating in parallel; a different number of production lines
can obviously be provided as a function of the throughput required (e.g. a single
production line or two, four or more production lines).
[0046] In known packaging machines, dosing very small doses of fluid product (of the order
of one millimeter of fluid product in each single-dose package) might result in a
relatively low precision (with an error of the order of ±6-8%). To solve this problem,
a dosing unit 26 may be used, comprising: a tank 50 holding a fluid product 5; at
least one feeding duct 27, which originates from tank 50 and ends with a delivery
mouth 51; and a peristaltic pump 52 which is arranged along the feeding duct 27 so
as to feed the fluid product 5 from tank 50 to the delivery mouth 51, where tank 50
is pressurized at a pressure which is higher than the atmospheric pressure.
[0047] Preferably, tank 50 has at least one nozzle 53, which is arranged in an upper portion
of tank 50 and is adapted to blow a compressed air jet into tank 50. Preferably, the
peristaltic pump 52 has an impeller which supports at least four thrust elements.
Preferably, the peristaltic pump 52 has an impeller which supports eight thrust elements.
A shutoff valve 54 is preferably provided, which is arranged along the feeding duct
27 upstream of pump 52.
[0048] In known packaging machines, it has been noted that, when operating at high speed,
the pattern of the semirigid plastic material strip has not always an optimal quality.
In particular, the pattern might be incomplete, i.e. have some larger or smaller zones
with no printing, due to a non-optimal contact between a printing head of a printing
device and the semirigid plastic material strip during the printing process. In order
to improve the contact between the printing head and the semirigid plastic material
strip, it has been suggested to decrease the distance between the printing device
and a fixed contrast opposed to the printing device so as to increase the pressure
with which the printing head pushes the semirigid plastic material strip against the
contrast; however, such a solution might determine the occurrence of an excessive
mechanical stress on the printing head, which stress might lead in a short time to
breakage of the printing head. In order to solve this problem, a printing unit 19
may be used, comprising: a conveying device 33, which feeds strip 15 along a conveying
direction C; a printing device 34 facing a first surface 10 of strip 15 so as to print
a pattern on strip 15; and a contrast plate 36, which is parallel to and faces the
printing device 34 so that strip 15 is arranged between the contrast plate 36 and
the printing device 34, where the contrast plate 36 comprises at least one nozzle
37, which opens up onto a second surface 8 of strip 15 and is adapted to release a
compressed air blow. The compressed air blown by nozzle 37 preferably creates a pressurized
air cushion 38 at the second surface 8 of strip 15 opposite to the printing device
34. The contrast plate 36 preferably comprises a plurality of nozzles 37 spaced apart
from one another. Preferably, the printing device 34 is a heat transfer printing device.
The printing device 34 preferably comprises a printing head 35 which is movable along
a printing direction S orthogonal to the conveying direction C and orthogonal to strip
15. The compressed air is preferably fed to nozzle 37 with a pressure from 2 to 6
bar. The compressed air is preferably fed to nozzle 37 with a pressure from 3 to 5
bar.
1. A unit (20) for the incision of a strip (15) made of a plastic material to cut two
distinct incisions (7, 9) into two opposite surfaces (8, 10) of the strip (15) in
a packaging machine (11) to manufacture a sealed single-dose break-open package (1);
the incision unit (20) comprises:
a conveying device (21), which feeds the strip (15) along a conveying direction (C);
two support plates (41), which are arranged on opposite sides of the strip (15), so
that each support plate (41) faces a corresponding surface (8; 10) of the strip (15);
and
at least two incision devices (42), each of which cuts an incision (7; 9) into a corresponding
surface (8; 10) of the strip (15) and comprises a cutting element (43), which is supported
by a support plate (41), and a contrast element (44), which is supported by the other
support plate (41);
the incision unit (20) is characterised in that:
the two support plates (41) are mobile so as to translate together along a translation
direction (T), which is orthogonal to the conveying direction (C);
the two incision devices (42) are arranged one next to the other and are aligned along
the translation direction (T); and
a first actuating device (46) is provided, which cyclically moves the two support
plates (41) forward and backward along the translation direction (T) between a first
position, in which a first incision device (42a; 42b) is operated so as to cut a first
incision (7; 9), and a second position, in which a second incision device (42b; 42a)
is operated so as to cut a second incision (9; 7), which is opposite to the first
incision (7, 9).
2. An incision unit (20) according to claim 1, wherein each support plate (41) supports
the cutting element (43) of an incision device (42) and the contrast element (44)
of the other incision device (42).
3. An incision unit (20) according to claim 1 or 2, wherein each cutting element (43)
comprises a blade.
4. An incision unit (20) according to claim 3, wherein each blade is V-shaped and each
contrast element (44) is flat.
5. An incision unit (20) according to any of the claims from 1 to 4, wherein each incision
device (42) comprises an adjusting organ (49), which is coupled to the cutting element
(43) or to the contrast element (44) and adjusts the distance between the cutting
element (43) or the contrast element (44) and the strip (15).
6. An incision unit (20) according to claim 5, wherein the adjusting organs (49) are
all arranged on a same support plate (41).
7. An incision unit (20) according to any of the claims from 1 to 6, wherein at least
one support plate (41) is mobile so as to cyclically move forward and backward, due
to a second actuating device (48), towards the other support late (41) and along an
incision direction (I), which is perpendicular to the strip (15) and perpendicular
to both the conveying direction (C) and the translation direction (T).
8. An incision unit (20) according to any of the claims from 1 to 7, wherein the conveying
device (21) comprises at least one feeding dandy roller (22), which is arranged upstream
of the support plates (41) and is mobile so as to allow the strip (15) to temporarily
stop between the two support plates (41).
9. A packaging machine (11) to manufacture a sealed single-dose break-open package (1);
the package consists of a first sheet (2) made of a semirigid plastic material, which
is arranged on top of and sealed to a second sheet (3) made of a flexible plastic
material, so as to define a sealed pocket (4) containing a dose of a product (5),
and has a pair of incisions (7, 9) to guide a controlled breaking of the first sheet
(2);
the packaging machine (11) comprises:
a first unwinding device (12) to feed a first strip (15) made of a semirigid plastic
material;
a second unwinding device (13) to feed a second strip (18) made of a flexible plastic
material;
an incision unit (20) to cut two incisions (7, 9) into the first strip (15) made of
a semirigid plastic material;
a forming station (16), which is arranged downstream of the incision unit (20) so
as to arrange the first strip (15) made of a semirigid plastic material on top of
the second strip (18) made of a flexible plastic material;
a first longitudinal sealing device (32) to longitudinally and laterally seal the
two strips (15, 18) to one another, so as to define at least one tube;
a dosing unit (26), which is arranged in the forming station so as to feed a dose
of a product (5) into the tube between the first strip (15) made of a semirigid plastic
material and the second strip (18) made of a flexible plastic material;
a second transverse sealing device (28), which is arranged downstream of the dosing
device (26) so as to transversely seal the two strips (15, 18) to one another in order
to define, along the tube, a series of pockets (4), each containing a dose of product
(5); and
a cutting device (31), which is arranged downstream of the forming station (16) so
as to transversely cut the tube in order to separate, in sequence, the sealed single-dose
packages (1);
the packaging machine (11) is characterised in that the incision unit (20) is manufactured according to any of the claims from 1 to 8.
10. A method for the incision of a strip (15, 18) made of a plastic material to cut two
distinct incisions (7, 9) into two opposite surfaces (8, 10) of the strip (15) in
a packaging machine (11) to manufacture a sealed single-dose break-open package (1);
the incision method comprises the steps of:
conveying the strip (15) along a conveying direction (C) and between two support plates
(14), so that each support plate (41) faces a corresponding surface (8; 10) of the
strip (15); and
cutting the strip (15) by means of at least two incision devices (42), each cutting
an incision (7, 9) into a corresponding surface (8; 10) of the strip (15);
the incision method is characterised in that it comprises the further steps of:
translating the two support plates (41) together along a translation direction (T),
which is orthogonal to the conveying direction (C); and
cyclically moving the two support plates (41) forward and backward along the translation
direction (T) between a first position, in which a first incision device (42a; 42b)
is operated so as to cut a first incision (7; 9), and a second position, in which
a second incision device (42b; 42a) is operated so as to cut a second incision (9;
7), which is opposite to the first incision (7, 9).
11. A method for the incision of a strip (15) made of a semirigid material according to
claim 10, wherein the two incision devices (42) are arranged one next to the other
and are aligned along the translation direction (T).
12. A method for the incision of a strip (15) made of a semirigid material according to
claim 10 or 11, wherein the strip (15) made of a semirigid material is temporarily
stopped during the strip incision step.
13. A dosing unit (26) of a packaging machine (11) for sealed single-dose packages (1);
the dosing unit (26) comprises:
a tank (50) holding a fluid product (5);
at least one feeding duct (27), which originates from the tank (50) and ends with
a delivery mouth; and
a pump (52), which is peristaltic pump and is arranged along the feeding duct (27)
so as to feed the fluid product (5) from the tank (50) to the delivery mouth (51);
the dosing unit (26) is characterised in that the tank (50) is pressurized at a pressure that is higher than the atmospheric pressure.
14. A unit (19) to print a deformable plastic material strip (15) of a packaging machine
(11) for sealed single-dose packages (1); the printing unit (19) comprises:
a conveying device (33), which feeds the strip (15) along a conveying direction (C);
a printing device (34), which is arranged in a fixed position along the conveying
device (33) and faces a first surface (10) of the strip (15) so as to print a pattern
on the strip (15); and
a contrast plate (36), which is independent and separate from the conveying device
(33), is arranged in a fixed position along the conveying device (33), and is parallel
to and faces the printing device (34) so that the strip (15) is arranged between the
contrast plate (36) and the printing device (34);
wherein the printing device (34) comprises a printing head (35), which in use contacts
the strip (15) with a given pressure so as to print a pattern on the strip (15);
the printing unit (19) is characterised in that the contrast plate (36) comprises at least one nozzle (37), which opens up onto a
second surface (8) of the strip (15) and is suited to release a blow of compressed
air so as to create a pressurized air cushion (38) in correspondence to the second
surface (8) of the strip (15) that is opposite to the printing device (34), said air
cushion (38) constitutes a deformable contrast against which the printing head (35)
pushes the strip (15).
15. A method to print a deformable plastic material strip (15) of a packaging machine
(11) for sealed single-dose packages (1); the printing method comprises the steps
of:
conveying the strip (15) along a conveying direction (C) by means of a conveying device
(33);
printing a first surface (10) of the strip (15) by means of a printing device (34),
which is arranged in a fixed position along the conveying device (33) and is coupled
to a contrast plate (36), which is independent and separate from the conveying device
(33), is arranged in a fixed position along the conveying device (33), and is parallel
to and faces the printing device (34) so that the strip (15) is arranged between the
contrast plate (36) and the printing device (34;
wherein the printing device (34) comprises a printing head (35), which in use contacts
the strip (15) with a given pressure so as to print a pattern on the strip (15);
the printing method is characterised in that it comprises the further step of releasing a blow of compressed air through a nozzle
(37), which is obtained through the contrast plate (36) and opens up onto a second
surface (8) of the strip (15) so as to create a pressurized air cushion (38) in correspondence
to the second surface (8) of the strip (15) that is opposite to the printing device
(34), said air cushion (38) constitutes a deformable contrast against which the printing
head (35) pushes the strip (15).