Note: Descriptions are shown in the official language in which they were submitted.
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CONVERTIBLE COMPUTER CONTROLLED FFS~ BAGGING MACHINE
TECHNICAL FIELD
toool~ The present invention relates to a convertible
computer controlled FFS machine and method of operation
capable of forming from a single machine pouches' of
different sizes and contents and particularly, but not
exclusively to a vertical form fill and seal (VFFS) machine
capable of operating at high speeds.
BACKGROUND ART
X00021 In the liquid packaging industry and specifically
for the packaging of liquid contents into pouches, it is
common practice to produce from a single machine a pouch
from a plastic film role and to fill it with a liquid
content simultaneously as the pouch _~s being formed and
sealed. Such machines are commonly referred to as vertical
form, fill and seal machines VFFS. These machines are
adapted to form a pouch of predetermined size and fill it
with a content of predetermined volume. Such a machine or
machines are commonly associated with conveyors which convey
the filled pouches to casers or to a bagger which places a
predetermined number of these filled pouches into bags.
Depending on the required desired output of a production of
the plant, several of these machines and conveyor lines are
installed. Further, dependent on the different sizes of
pouches to be produced with different volume contents,
several more machines and floor space is occupied by such
operation. Accordingly, large investments are required to
purchase machinery and to provide the requisite floor space
to install such machines, conveyors and bagging equipment.
Therefore, there is a need to provide a reduction of such
high costs in equipment floor space and associated labour.
Looo3~ Further, these machines and their component parts
require down time to adjust the machine to varying
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parameters such as the change of the pouch size, the type of
liquid to be bagged, the need to clean the machine for
sanitary purposes and particularly so in diary operations,
to modify the sealing jaws to suit different plastic film
compositions, etc, etc. This down time of these machines is
also an expensive factor in the cost of operation and of the
number of machines required in the bagging plant.
SUMMARY OF INVENTION
(0004) It is a feature of the present invention to
provide a convertible, computer controlled, form, fill and
seal bagging machine and method which overcomes the above
mentioned disadvantages of the prior art..
(0005) A further feature of the present invention is to
provide a convertible computer controlled, form, fill and
seal FFS bagging machine capable of producing, from a single
machine, pouches of different size and content volumes and
wherein the machine is fully automatically controlled by a
computer.
(0006) Another feature of the press~nt invention is to
provide a method of forming, filling and sealing pouches of
a desired selectable programmed size and volume from at
least two or more program sizes from a single forming,
filling and sealing machine.
(0007) Another feature of the present invention is to
provide a FFS bagging machine with increased output capacity
and speed of operation.
(0008) According to the above features, from a broad
aspect, the present invention provides a convertible
computer controlled form, fill and seal (FFS) bagging
machine. The bagging machine comprise~~ film draw means to
draw a folded film sheet about a pouch former with the film
sheet having overlapped along long_Ltudinal free edge
portions. First sealing means is provided to heat fuse the
overlapped edge portions together to form a hollow film
tube. Temperature control means is provided to control the
temperature of the sealing means. Transverse sealing means
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is provided to form a transverse seal across the follow film
tube and is synchronized with the first sealing means.
Content feed means is provided to supply a predetermined
content in the hollow tube at a pouch forming station
thereof. A computer control means is provided to control
the film draw means, the sealing time of the first sealing
means, the temperature control means, the sealing time of
the transverse sealing means, and the rate of feed of the
content feed means whereby to produce pouches of a
programmed size filled with a programmed content volume.
The machine has the capability of producing pouches of
different sizes with different content volumes by computer
inputting means.
tooos7 According to a further broad aspect of the present
invention there is provided a method of forming, filling and
sealing pouches of a desired selectable programmed size and
content volume from two or more programmed sizes and from a
single pouch forming, filling and se<~ling machine. The
method comprises the steps of selecting from a computer
controlled panel desired parameters of a pouch to be formed
and filled with a content. A folded film is automatically
drawn about a pouch former with the film having overlapped
free edge portions. The overlapped edge portions are fused
together by a heat sealing means to form a vertical seal to
produce a hollow film tube. The temperature of the sealing
means is controlled by the computer. A transverse seal is
formed by sealing jaws across the hollow film tube to form a
transverse seam across the hollow film tube. A content is
fed into the hollow film tube at a pouch forming station
thereof. A computer controls the drawing speed of the
folded film, the temperature and sealing time of the sealing
means, the sealing time of the sealing jaws, and the feed
rate of the content whereby to produce pouches of a
predetermined size filled with a predetermined programmed
content volume.
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BRIEF DESCRIPTION OF DRAWINGS
toolol A preferred embodiment of the present invention
will now be described with reference to the accompanying
drawings in which:
toolll Figure 1 is a schematic view of a dual head
vertical form, fill and seal (VFFS) bagging machine of the
present invention incorporated into a bagging system,
too121 Figure 2 is a block diagram showing the automized
computer controlled operation of the machine whereby to
produce pouches of a predetermined programmed size filled
with a predetermined programmed content volume,
tool3~ Figure 3 is a schematic enlarged view of the
hollow film tube drawn over the vertical sealing bar area of
the pouch former,
tool4~ Figure 4 is a view similar to Figure 3 but showing
a vertical seam being formed by striking the overlapped film
portions with three successive strokes of the vertical
sealing bar, and
too151 Figure 5 is a simplified perspective view of the
film supply mechanism and control.
DESCRIPTION OF PREFERRED EMBODIMENTS
too161 Referring to the drawings, more particularly to
Figure 1 there is shown generally at 10 a convertible
computer controlled vertical form, fill and seal (VFFS)
bagging machine having a dual head 11 and 11'. Such
machines are well known in the art and as above described
they are equipped to produce a pouch of a single
predetermined size having a predetermined liquid content.
Each of these heads 11 and 11' are provided with film drives
12 whereby to pull an overlapped film sheet 13 over a pouch
former 14 which has a flat section 14' to form the back
support of a vertical sealing bar .L5 under which the
overlapped longitudinal free edge portions 16 are disposed,
as more clearly illustrated in Figure 3. The pouch former
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14 forms a hollow film tube 17. Such pouch formers are well
known in the art.
fool~l As shown in Figure 2 the vertical sealing bar 15
has a resistive heating element 18 and the temperature of
the resistive element and the vertical sealing jaw is
controlled by a temperature control 19 associated with the
vertical sealing bar 15 which is actuated by a piston 20 or
other suitable actuation means to position the vertical
sealing bar against the overlapped film and to retract it
therefrom. The application time of the piston is also
controlled by the computer 21.
fools As shown in Figure 1 each of the heads 11 and 11'
are fed a liquid, such as milk, water or other beverage
located in a supply container 24 and 21, respectively. The
level of liquid within the containers is maintained constant
by valve s24" and 21" to maintain a con:~tant static pressure
of the liquid fed to the control valves 22 and 22' which are
controlled by the computer 21 to adjust a constant flow rate
of the fluid in the feed pipes 23 and 23'. Level sensors 9
and 9' feed control signals to the computer controller 21.
The feed pipes 23 and 23' release the liquid 24 into pouches
25 and 25' being formed and located above a transverse
sealing means, herein a transverse sealing jaw assembly 26
and 26'. The feed of the liquid 24 is continuous. The
sealing jaws 26 form a transverse seal for the top end 27 of
a formed pouch 25 filled with the liquid 24 therein.
Simultaneously the transverse seal slit: the filled pouch 25
to release it from the film tube 17. The vertical sealing
bar 15 also forms the bottom seal of the upper pouch 25
being filled.
tooi97 The computer controlled means, herein the computer
21 controls a motor, not shown, to drive the film drive 12
as schematically illustrated in Figure 2. The computer
control 21 also controls the piston 2f3 which actuates the
transverse sealing jaws 26. A temperature control 29 is
also controlled by the computer 21 to control the
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temperature of the transverse sealing jaws 26 as
schematically illustrated in Figure 2.
too2o~ The computer 21 by controlling these parameters
can produce pouches of predetermined size and filled with a
predetermined content volume of the liquid. These different
size bags with different liquid volumes are stored in a
memory 30 of the computer and through an input screen 31
located on the control panel 32 of the machine 10, a
predetermined size pouch and content volume can be
preselected by touch control buttons 3:3. The machine will
self-adjust itself whereby to form, and fill pouches of
different sizes. Also, by controlling i:he pistons 20 and 28
the pressure of the vertical and transvE=rse sealing bars can
be varied depending on the film composition and the size of
pouches formed. For example, and with reference to Figure
4, if the vertical sealing bar 15 is three times as long as
a pouch being formed each time the vertical sealing bar is
applied against the drawn hollow film tube 17 the vertical
sealing bar will strike the overlapped film portions 16
three times before the film tube is drawn below the vertical
sealing bar. Accordingly, in order to ensure that the
vertical sealing bar does not burn through the overlapped
free edge portions 16, the temperature of the vertical
sealing bar must be controlled whereby when the vertical
sealing bar has struck the overlapped film portion 16 at its
bottom zone C a perfect vertical seal will be formed. A
seal will begin to form in zone A and then progressively in
zone B where the seal has struck that zone twice.
Therefore, after having been struck three times in zone C a
perfect seal is formed. The temperature and pressure of the
vertical sealing bar is thus an important feature and it is
automatically controlled by the controller of the computer
and depending on the size of pouches being formed or the
length of hollow film tubing drawn at each sealing stroke of
the vertical sealing bar and also the type of film being
used. This is all programmed in the memory 30 of the
computer and it automatically adjusts itself depending on
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the input commands received from the input screen 31. The
input screen 31 can also switch to a display screen 34
automatically by depressing one of the: control buttons 33
whereby to display information as will be described later.
too217 The twin head vertical form, fill and seal machine
as shown in Figure 1 is herein shown adapted in a pouch
bagging system and wherein the machine 10 feeds filled
pouches 25 onto a conveyor 35 through orientation boxes 36
and 36' associated with each of the heads 11 and 11',
respectively. The orientation boxes 36 and 36' position the
filled pouches 25 with a predetermined orientation onto the
conveyor 35. The computer 21 is fed signals relating to the
speed of the conveyor 35 and it also knows the drop time of
the pouches 25 from their respective heads and this drop
time is dependent on the size of the pouches and the liquid
content therein. This is all pre-calculated by the computer
when the parameters are inputted into the computer.
Accordingly, the computer is aware of the spacing between
the pouches 25 on the conveyor belt. The computer also
adjusts the synchronized interval between the servo-motors
(not shown) which drive the two heads to achieve this
substantially constant spacing between the pouches 25 which
is of great importance to the bagging machine 37.
to0227 Oriented pouches 25 on the conveyor 35 are
conveyed to a bagger machine 37 to place a predetermined
number of filled pouches into a bag 38 supported under a
discharge opening 39 of the bagger machine 37. The bagger
machine 37 is also controlled by the computer as shown in
Figure 2. To effect a change of pouch size it is merely
necessary to change the format selection on the computer
screen 31 and the machine automai~ically adjusts its
equipment to produce the selected format and its content.
(00237 A counter 40 is positioned at a convenient
location along the conveyor 35 to count the filled pouches
25 which are conveyed thereon and it feeds signals to the
computer 21; as shown in Figure 2, whereby the computer can
control the number of filled pouches being placed in each
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bag 38 supported under the bagger machine 37. Once a bag 38
is filled with a predetermined number of filled pouches 25,
it is then discharged through a discharge conveyor 41 into a
bag closing station 42 to close an opened top end 38' of the
loaded bag. After a bag is discharged from under the bagger
machine, a bag positioner positions another bag under the
bagger machine to accept a further predetermined number of
filled pouches therein. Such bagger machines are well known
in the art and are described in the patient literature. The
signals from the counter 40 are stored in the memory 30 of
the computer whereby it can keep record and display the
number of pouches produced by each of the twin heads of the
VFFS machine 10. The computer can also display the number
of pouches left to be produced by t:he machine and the
production time which is left for each of the twin heads.
It is pointed out that if one of the heads is idle due to a
film roll change, the other head may continue operation and
vice-versa. By controlling the various parameters, the
computer can also control the speed of operation of the twin
head VFFS machine. The bagger is also automatically
controlled.
too24~ With reference now to Figure 5, there is shown the
construction of a film dispensing assembly 50 in order to
achieve high speeds of operation wherein this machine can
dispense filled pouches, above 125 pouches per minute, with
the pouches being formed approximately 11 inches long by 6
inches wide. As hereinshown, the machine houses two film
rolls 52 , only one being shown and illustrated herein which
feeds a film sheet 5l to each of the formers 11 and 11'.
The film roll 52 has a support shaft 53 which is coupled to
a drive motor 54 which rotates the film roll 52 in the
direction of arrow 55 whereby to dispense film at a
predetermined rate. The film sheet 51 is disposed about a
stationary guide roll 56 which feeds a film sheet to a
displaceable film tensioning means 57 which consists of two
or more dancer rolls, herein dancer rolls 58 which are each
secured to a displaceable weighted support frame 59. The
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support frame 59 is held in guided displacement between
guide rails 60 or other suitable guide means. The weighted
frames and the roller apply a downward force in the
direction of arrow 61 whereby to maintain the film sheet 51
taut as it is fed and guided about the forrners 11 and 11'.
foo25~ When operating at guide means the film drive 12
which pulls the film about the former causes the
displaceable weighted frame 59 to move upwardly due to this
pulling force and therefore it is important to control the
tension in the sheet to prevent the film sheet 51 from
stretching changing characteristic of the film which could
be detrimental when seals are being formed by the sealing
heads. Accordingly, it is important t=o dispense the film
sheet at a rate proportional to the draw speed to maintain a
substantially constant tension within the film sheet. This
is achieved by providing detectors 62 'which sense a marker
63 on the weighted, displaceable frame 59 to detect its
position. These detectors 62 feed positioning signals to
the control computer 21 which in turn control the motor 54
as illustrated in Figure 5. Accordingly, the computer and
the drive motor 54 control the position of the weighted
frame 59 within a predetermined mid-range dependent on the
draw speed and rate of feed. However, :should the draw speed
required by the inputted parameters exceed a predetermined
value, it becomes necessary to lower the weight of the
displaceable film tensioning frame 59 and to do so there is
further provided a counter-weight mechanism which is simply
a counter-weight 64 of known weight se=cured about a guide
pulley 65 and to an attachment 66 secured to the
displaceable frame 59 whereby to pull the frame upwardly to
thereby maintain the film sheet taught a.t very high speeds.
too2s7 Although the drawings herein illustrate a vertical
form, fill and seal machine with twin heads, it is to be
understood that the convertible aspect of the machine can be
applied to horizontal formers. Accordingly, the method of
forming, filling and sealing pouches of a desired selectable
programmed size and volume from two or more programmed sizes
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and from a single bag forming, filling and sealing machine,
is a novel feature which achieves the desired features of
the invention as herein before mentioned. The feature of
selecting from a computer controlled panel desired
parameters of a pouch to be formed and filled with a
predetermined content volume and from a single machine is an
important feature of the present invention.
too2~~ As the machine automatically draws a folded film
about a pouch former with the film having overlapped free
edge portions along which a vertical sealing bar is applied
to heat fuse the film to form a -Vertical seal in a
controlled manner depending on the bag :sizes all of which is
controlled by a computer to ensure a perfect seal for
different size pouches. The temperat=ure of the sealing
means as well as the pressure of the vertical sealing bar is
controlled by the computer as the same real may be subjected
to two or more heat sealing application:. The computer also
controls the transverse sealing jaw assembly 26 to form a
transverse seal across the hollow film tube and
simultaneously detach the sealed bag from the film tube. A
liquid content is continuously fed into the film tube as
filled pouches are being formed all of which is controlled
by the computer 21. Accordingly, the computer 21 controls
the drawing speed of the folded film, the temperature and
sealing time of the vertical sealing bar 15 and the
transverse sealing jaw assembly 26 and the feed rate of the
liquid content through the valve 22 whereby to produce
pouches of a predetermined programmed size filled with a
predetermined program content volume.
too2s7 The computer also selects the: sealing temperature
of the vertical sealing bar and the selected sealing
pressure thereof depending on the size of pouch being formed
and the film material being used. The speed of operation of
each of the twin heads is also controlled by the computer 21
as well as the speed of the bagger machine 37 and the speed
of the conveyors 35 and 41 to control t:he production output
of the system as illustrated in Figure l..
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too291 It is within the ambit of the present invention to
cover any obvious modifications of the preferred embodiment
described herein, provided such modifications fall within
the scope of the appended claims.
