Information
-
Patent Grant
-
6694705
-
Patent Number
6,694,705
-
Date Filed
Friday, May 18, 200123 years ago
-
Date Issued
Tuesday, February 24, 200420 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Rada; Rinaldi I.
- Durand; Paul
Agents
-
CPC
-
US Classifications
Field of Search
US
- 053 428
- 053 440
- 053 458
- 053 467
- 053 473
- 053 565
- 053 111 R
- 053 3707
- 053 7
- 053 122
-
International Classifications
-
Abstract
A defoaming apparatus (22) defoams a foamable product that is dispersed into a container such as a TETRA REX gable-top carton (80). The defoaming apparatus (22) creates a sonic shock wave (110) that destroys most if not all of the bubbles of the foamable product. The defoaming apparatus (22) has a body (100) that defines a recessed cavity (102). A pair of electrodes (106, 108) is located within the recessed cavity (102). The opening to the cavity (102) can include a radio frequency filter (114) covering to absorb radio waves created from the sonic shock wave (110). The defoaming apparatus (22) is preferably disposed immediately after the filling of the container (80).
Description
FIELD OF THE INVENTION
The present invention relates to defoaming devices for foamable products. Specifically, the present invention relates to a defoaming device utilized on a packaging machine to decrease the foam level in a container prior to sealing of the container.
BACKGROUND OF THE INVENTION
In the packaging industry, productivity is synonymous with the ability to produce a greater number of cartons per hour than previous machines. In the field of form, fill and seal packaging machine, the ability to produce higher capacity machines is accomplished by analyzing, and as necessary, modifying each action performed on the machine. Through analyzing each action performed on the machine, the dwell time may be lessened while the indexed movement is increased in order to achieve higher capacity on the packaging machine. The dwell time is defined as the time period that each preformed container is stationary on the machine while an action is performed on the container. The indexed movement is defined as the time period that each pre-formed container is conveyed along the packaging machine from one station to the next.
For example, on a linear form, fill and seal packaging machine such as a TETRA REX® packaging machine available from Tetra Pak, Incorporated of Chicago, Ill., once a pre-formed container is filled with a product, conveyance of the container must be controlled to prevent sloshing of the product onto the sealing area of the container. However, it is desired to increase the conveyance speed of the product-filled container. To that end, the motion profiles of the conveyance of containers is controlled as set forth in U.S. Patent No. (co-pending U.S. patent application Ser. No. 08/848,888) entitled Servo-Controlled Conveyor System For Carrying Liquid Filled Containers, assigned to the assignee of the present invention.
Another possibility for increasing capacity would be to reduce the number of indexed dwell positions on the conveyor line. One possible dwell position that may be eliminated is the extra dwell position between the filling station and top sealing station. This station allows for the product foam in a recently filled container to settle prior to top sealing, which prevents wetting of the sealing area of the container with product foam. Other packaging machines such as rotary filling machines and vertical form, fill and seal machines have exhibited similar problems with foamable products.
One defoaming technique is set forth in U.S. Pat. No. 4,295,502, entitled “Method And Apparatus For The Elimination Of Foam Above The Level Of A Liquid, And Particularly Above A Packaged Liquid Such As Milk.” This technique discloses the use of ultrasonic waves to decrease the product foam in a container through disruption of the foam bubbles. The technique requires ultrasonic equipment positioned above the conveyor line. However, the ultrasonic device will increase the noise level on the packaging machine, and if other ultrasonic devices are employed on the machine, such as ultrasonic fitment applicators, then already high decibel levels may be doubled, coming close to intolerable decibel levels. Safeguards and other additions may be added to the machine to reduce noise, however, this further increases the cost of the packaging machine. Moreover, the use of ultrasonics for defoaming purposes has proven ineffective.
An alternative defoaming device is needed in the packaging industry to increase the packaging capacity of machines. Such a device desirably reduces foaming of the newly filled package, with minimal if any impact on the operating speeds of the overall packaging machine operation. Most desirably, such a device fits within the known physical parameters and sizing of known packaging machines.
SUMMARY OF THE INVENTION
The present invention provides an alternative to ultrasonic defoaming which effectively defoams a container filled with a foamable product. The present invention accomplishes this by providing a defoaming device that creates a shock wave to destroy or collapse the bubbles of a foamable product inside a container after filling.
One aspect of the invention is a defoaming device having a body with a reflective recessed cavity. Inside the cavity are two electrical terminals that, when a voltage is applied to one terminal, an arc is created between the terminals to complete the circuit. The discharge or arc superheats the air inside of the recessed cavity to create a shock wave. The shock wave is directed toward the container to destroy the bubbles of the foam.
Another aspect of the invention is a packaging machine having such a defoaming device positioned between a filling station and a top sealing station. Yet another aspect of the invention is a method for defoaming a carton filled with a foamable product. It is a primary object of the present invention to provide a method and apparatus to defoam pre-formed containers filled with a product on a packaging machine.
Other features and advantages of the present invention will be apparent from the following detailed description, in conjunction with the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a top perspective view of a packaging machine;
FIG. 2
is an isolated view of the fill pipe, defoaming device, prefolder and top sealer of the packaging machine of
FIG. 1
;
FIG. 2
a
is an isolated view of the defoaming device of
FIG. 2
;
FIG. 3
is a partial cross-section side view of an open ended gable top carton;
FIG. 4
is a partial cross-sectional side view of a folded top gable top carton of the prior art;
FIG. 5
a
illustrates a gable top carton being filled with a foamable product;
FIG. 5
b
illustrates a filled gable top carton with foam;
FIG. 5
c
illustrates a filled gable top carton being defoamed at the defoaming device of the present invention;
FIG. 5
d
illustrates a defoamed gable top carton;
FIG. 6
is an isolated view of an alternate embodiment of the defoaming apparatus of the present invention over a plastic container such as a PET bottle which can be filled on a rotary filling machine;
FIG. 6
a
is a cross-sectional plan view of the apparatus of
FIG. 6
, more clearly illustrating the filter/screen of the apparatus;
FIG. 7
a schematic view of a TETRA TOP™ packaging machine having the defoaming device of the present invention integrated thereon;
FIG. 8
is a schematic diagram of a vertical form, fill and seal packaging machine;
FIG. 9
is a cross-sectional view of the machine
FIG. 8
with the defoaming device of the present invention disposed about the fill pipe;
FIG. 10
is an electrical schematic diagram of a trigger circuit used in one embodiment of the present invention; and
FIG. 11
illustrates a sound guide that is used in one embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described presently preferred embodiments with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiments illustrated.
The present invention is directed toward a form, fill and seal packaging machine, for example a linear packaging machine for gable-top cartons such as a TETRA REX® machine available from Tetra Pak, Incorporated of Chicago, Ill. Those skilled in the art will, however, recognize that the present invention may be utilized with other machines to defoam a foamable product. Linear packaging machines may process one, two or any multiple of cartons simultaneously with each multiple of cartons being conveyed one indexed movement from station to station. The present invention allows for cartons filled with a foamable product to be defoamed prior to pre-folding and/or top sealing.
As shown in
FIG. 1
, a dual line packaging machine
20
for forming, filling and sealing cartons generally includes a defoaming device
22
, a top sealing station
24
and a filling station
26
, a sterilization station
28
which is composed of an ultraviolet radiation station
30
and a hydrogen peroxide station
32
, a bottom forming station
36
, a carton opener
37
, and a carton blank magazine
38
. From an operational perspective, the front
40
of the packaging machine
20
is where the processing begins, and the rear
42
is where the finished cartons are dispensed for distribution.
The packaging machine
20
may be divided along a horizontal plane defined by a table top
44
. The table top
44
divides the packaging machine
20
into an upper half
46
and a lower half
48
. A frame
50
defines the general structure of the packaging machine
20
and supports the table top
44
and the various stations. The lower half
48
of the machine
20
includes servomotors, drive cylinders, cam drives and other components. The upper half
46
includes the various stations, the product tank
56
, the filtered air system
58
, the conveyor system
60
, not shown in
FIG. 1
, and other components to process the cartons.
As shown in
FIG. 2
, the defoaming device
22
is positioned between the filling station
26
and a pre-folder station
62
. Such a filling station
26
is described in co-pending U.S. patent application Ser. No. 08/897,554, entitled “Dual Stream Filling Valve” and in copending U.S. patent application Ser. No. 08/816,056, entitled “Elliptical Cleaning Box For Filling Apparatus,” both of which are hereby incorporated by reference.
Further down line at the top sealing station
24
is an oven
64
for heating the panels for sealing, and the top sealer device
66
for sealing the top fin panels of a carton together to create a form, filled and sealed carton. The top fin panels form the sealing area as described below. Preferably the defoaming device
22
will cover two open top cartons being processed on a dual carton processing packaging machine
20
. For example, two cartons are filled simultaneously at two fill pipes
70
a-b
, then conveyed to the defoaming device
22
in the next indexed movement to be defoamed, if necessary. Both cartons are conveyed under the defoaming device
22
for defoaming before the pre-folding station
62
.
Alternatively, although not shown, two smaller defoaming devices
22
can be used, with one device each being positioned over a carton for individually and independently defoaming the cartons before pre-folding at the pre-folder station. In still another alternative (also not shown) one carton is defoamed during the dwell while the other carton is defoamed during the indexed movement. Additionally, the packaging machine
20
may process only a single carton at each station, or it may process a multiple of cartons at each station. The defoaming device can be modified to accommodate any of the above alternatives, or any multiple of cartons processed in an indexed movement on the packaging machine
20
, without departing from the scope and spirit of the present invention.
The positioning of the defoaming device
22
over a dual processing line is best shown in FIG.
3
. Two cartons
80
a,b are positioned below the defoaming device
22
. The defoaming device
22
has a body
100
that defines a recessed cavity
102
. Preferably, the recessed cavity
102
has a parabolic shape into the body
100
thus forming a parabolic ceiling
104
of the recessed cavity
102
. This ceiling
104
is reflective to direct air towards the interior of each carton
80
a,b
. Projecting from the body
100
are two electrical terminals
106
and
108
. For example, terminal
106
can be a cathode and terminal
108
can be an anode. For example, a high voltage current is sent through terminal
106
thereby establishing an electrical arc
109
between terminal
106
and terminal
108
. A sonic shock wave, illustrated by arrows
110
, is created by the electrical discharge. The shock wave
110
arises from the super-heating of the air within the recessed cavity
102
by the electrical discharge, similar to lightening. As the air heats, it expands thereby increasing the pressure within the recessed cavity
102
. The sonic shock wave
110
, or compressed air, is directed toward the interior of the cartons
80
a,b
to destroy the foam bubbles thereby defoaming the product in anticipation of pre-folding. The reflective ceiling
104
acts to reflect all vectors of the shock wave toward the interior of the cartons
80
a,b
to increase the defoaming effect of the shock wave
110
. However, those skilled in the art will recognize that the ceiling
104
may be of a non-parabolic shape and be within the scope and spirit of the present invention.
The body
100
may be encapsulated by a protective shield
112
composed of a metal or other protective material. Also, a protective screen
114
may be placed over the recessed cavity to prevent contact with the terminals
106
and
108
. The screen
114
may also be a radio frequency filter to absorb radio waves created with the sonic shock wave. The radio waves may have a deleterious effect on the operation of the packaging machine. A power supply
116
is connected to the terminals
106
or
108
to supply the high voltage current. One of the terminals
106
or
108
may also be connected to a ground
118
.
A carton
80
filled with a foamable product
201
filled therein is shown in FIG.
3
. The liquid level is approximately shown at line
199
. The foamable product
201
has bubbles
200
that approach the sealing areas
91
of the carton
80
. The same carton
80
is illustrated in
FIG. 4
undergoing pre-folding without defoaming, as performed in the prior art. As shown in
FIG. 4
, the bubbles
200
of the foamable product
201
“wet” the sealing areas
91
of the carton
80
. Such wetting will interfere with proper sealing of the carton
80
and render the product filled carton
80
defective. For example, in a carton
80
having a cross section of 70 mm×70 mm, a ten millimeter thick layer of foam will require approximately forty-nine milliliters of volume. In a typical one liter carton, the volume between the level of the product and the top of the carton is approximately forty-nine milliliters. Thus, it is obvious that the foam will wet the sealing area if the carton is not defoamed, or allowed to settle prior to sealing.
FIGS. 5
a-d
illustrate the filling, defoaming and pre-folding of a single carton. In
FIG. 5
a
, a carton
80
is bottom-up filled with a foamable product
201
such as milk. A fill pipe
207
with a nozzle
209
attached thereon fills the carton as it is lowered on a lifter
211
. The liquid level
199
remains in proximity to the nozzle
209
during the entire filling process to reduce the amount of foaming. In
FIG. 5
b
, the carton
80
is now filled with a foamable product
201
and conveyed to the defoaming device
22
. The carton may contain any volume from one liter to one half gallon to one gallon. The cross-section of the carton may vary, for example from a 70 mm×70 mm cross section to a 47 mm×47 mm cross-section to a 70 mm×95 mm cross section. In
FIG. 5
c
, the defoaming device
22
is defoaming the carton. The terminals
106
and
108
create an electrical discharge, and the heated air in the form of one or more shock waves
10
is directed by the reflective ceiling
104
toward the bubbles
200
of the foam of the foamable product
201
. A single electrical discharge with an energy of 2×10
−5
joules has been found to be sufficient to collapse all of the foam bubbles in a carton having a cross-section of 70 mm×70 mm. The voltage delivered may be 15 kilovolts and the distance between the electrodes and the foam may be 1 to 2 centimeters. However, other parameters may be used in practicing the present invention. In
FIG. 5
d
, a carton with a defoamed product is ready for pre-folding.
An alternate embodiment of the defoaming apparatus
122
is illustrated in
FIGS. 6 and 6
a
. The alternative defoaming apparatus
122
is constructed as a semi-isolated component on a machine. In this embodiment, the defoaming apparatus
122
has a built-in step-up transformer
300
that receives standard voltage from a power supply along standard voltage line
301
, and transforms the electricity to a higher voltage for delivery to a high voltage power line
302
and to the electrode
106
. A ground
303
is connected to electrode
108
for delivering the after-effects of the arc/charge
109
to ground.
In a present embodiment, the electrical circuit
400
includes a trigger circuit
402
, as shown in FIG.
10
. The electrical circuit
400
includes a high voltage power supply
404
, a current limiting resistor
406
, a storage capacitor bank
408
, a discharge resistor
410
, a discharge relay
412
and the electrodes
106
,
108
. The trigger circuit
402
enables the initiation of a spark upon receipt of a control signal. It has been observed that in a circuit without a trigger circuit, a spark will initiate when the potential (voltage) across the electrodes reaches a “value” sufficient to overcome the resistance of the air between the electrodes. As will be recognized by those skilled in the art, this “value” can be dependent upon a number of external or environmental factors, such as temperature, humidity, ion concentrations and the like.
To overcome the potential for inadvertent spark initiation, the trigger circuit
402
uses an ionization method in which a high voltage trigger pulse is applied to one side of an insulating plate
414
. This ionizes the gas (typically air) between the electrodes
106
,
108
to initiate the discharge (spark).
In an effort to further reduce the opportunity for inadvertent spark initiation, it has been found that it is desirable to minimize or eliminate fouling the electrodes
106
,
108
, which can occur by, for example, the accumulation of ionic material (salts, milk, juice, soap and the like) on the electrodes
106
,
108
. As will be recognized by those skilled in the art, electrode
106
,
108
fouling can affect the spark, and typically compromises spark generation by lowering the resistance path from the high voltage electrode
106
to ground. It has been found that fouling can be reduced or eliminated by spacing the defoaming device body
100
and electrodes
106
,
108
from the product as it is filled into the carton
80
. In such an arrangement, a sound guide
500
, such as that illustrated in
FIG. 11
, can be positioned between the body
100
and the carton
80
. In this manner, any liquid that may project as the foam or bubbles collapse will not project so far as to contact, land on, or accumulate on the defoaming device
22
and in particular on the electrodes
106
,
108
. In one embodiment, as illustrated in
FIG. 11
, the sound guide
500
has a body
502
that is configured as an elongated cylindrical tube. The tubular body
502
essentially envelopes the shock waves
110
that emante from the spark and directs the waves
110
onto the foamed product
201
in the carton
80
.
As shown in
FIG. 6
, the foamable product
201
is filled into a plastic container
333
having a rim
351
. The plastic container
333
maybe any type of plastic container such as a PET bottle, a high-density polyethylene bottle, or the like. The product may be any type of foamable product such as milk, cranberry juice, pineapple juice and grapefruit juice, as well as other foamable food products, and other foamable non-food products. The apparatus
22
may be integrated on various types of filling machines such as rotary fillers, linear fillers, vertical fillers and even in batch foamable product processing units. The defoaming apparatus
22
of the embodiment of
FIG. 6
obviates the need for connecting high voltage power lines to the machine. Such high voltage power lines may interfere with the operation of the machine and can increase the potential for injury to machine operators. The defoaming apparatus
22
is connected to a standard power supply line, for example a 110 volt power line. This electricity is then transformed to a higher voltage by the transformer
300
within the apparatus
22
, thus providing a safer work environment and also limiting any interference that a high voltage line might have on a machine.
As shown in
FIG. 7
, an alternative packaging machine that may use the defoaming device of the present invention is generally designated
500
. The machine
500
creates a package with a fiberboard based body and an injection molded plastic top known as the TETRA TOP™ package that is available from the aforementioned Tetra Pak, Incorporated. In operation, a web of material
502
is formed into a carton sleeve at a forming station
504
. The sleeve is placed on a mandrel
506
and rotated to an injection molding station
508
where the plastic top is created. The partially formed package is placed on a conveyor
509
. The package is filled at a filling station
510
with a foamable product
201
that is received from a product tank
512
. The defoaming apparatus
22
is disposed adjacent the fill station
510
, similar to the arrangement on the gable-top carton packaging machine
20
. The bottom of the package is sealed at a bottom forming station
514
and the bottom flaps are sealed at a flap sealing station
516
. At a discharge point
518
, the package is released from the conveyor
509
for further distribution. The defoaming apparatus
22
will defoam the product filled package allowing for better bottom sealing of the package.
Yet another packaging machine that may utilize the apparatus
22
is a vertical form, fill and seal packaging machine. An example of such a machine is shown in
FIGS. 8 and 9
. The machine fabricates fiberboard packages such as the ubiquitous TETRA BRIK® package, or flexible plastic pouches such as a TETRA POUCH™ package. As shown in
FIG. 8
, the vertical packaging machine
600
receives a web of material
602
. The material
602
is formed around a fill tube
604
. The material is formed into a tube
607
by a longitudinal sealer
606
. The package is then cut-away from the tube
607
at a transversal sealer
608
. As shown in
FIG. 9
, the defoaming apparatus
22
can be mounted about the fill pipe
604
between the longitudinal sealer
606
and the transversal sealer
608
. The apparatus
22
can also contact the bubbles
200
and/or the foamable product
201
.
From the foregoing, it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the normal concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims.
Claims
- 1. A defoaming device for a packaging machine for filling a series of containers and sealing the containers, the defoaming device comprising:a body having a reflective recessed cavity, the body positioned over the container path; a first electrical terminal within the reflective recessed cavity; a second electrical terminal within the reflective recessed cavity, the second electrical terminal in electrical proximity to the first electrical terminal; a power supply in electrical flow communication with the first electrical terminal to provide a high voltage current to the first electrical terminal in order to create an arc between the first electrical terminal and the second electrical terminal so as to generate a shock wave; and a trigger circuit having a conductive element disposed in electrical proximity to the first and second electrical terminals to initiate arc generation.
- 2. The defoaming device in accordance with claim 1 further comprising a protective shield about the body.
- 3. The defoaming device in accordance with claim 1 further comprising a radio frequency filter placed at an opening to the recessed cavity.
- 4. The defoaming device in accordance with claim 1 wherein the defoaming device is positioned prior to a pre-folding station of the packaging machine.
- 5. The defoaming device in accordance with claim 1 wherein the perimeter of the recessed cavity encompasses two containers for simultaneous defoaming.
- 6. The defoaming device in accordance with claim 1 including a sound guide disposed adjacent the body and configured to direct the shock wave.
- 7. A method for processing a series of containers on a packaging machine the method comprising the steps of:filling a container with a foamable product at a fill station of the packaging machine; defoaming the product in the container by creating an electrical discharge within a recessed cavity of a body of a defoaming device, the recessed cavity having a reflective ceiling, the electrical discharge generating a shock wave that is directed onto the foamable product in the container; providing a trigger circuit having a conductive element in electrical proximity to the defoaming device; generating the electrical discharge by actuating the trigger circuit; and sealing the top of the container to create a filled and sealed container.
- 8. The method in accordance with claim 7 wherein the container is a carton and further comprising the step of prefolding a plurality of top panels of the carton prior to sealing.
- 9. The method in accordance with claim 7 wherein the electrical discharge superheats the air inside of the recessed cavity creating a shock wave that collapses foam inside of the container.
- 10. The method in accordance with claim 7 wherein the foamable product is milk.
- 11. The method in accordance with claim 7 wherein a single electrical discharge is applied to every container.
- 12. A packaging machine having a series of cartons conveyed along a path, the packaging machine comprising:a filling station for filling each of the cartons with a foamable product; a top sealing station for sealing a plurality of top panels for each of the cartons to create a formed, filled and sealed carton; and a defoaming device disposed between the filling station and the top sealing station, the defoaming device for defoaming a filled carton, the defoaming device comprising a body having a reflective recessed cavity, the body positioned over the carton path; a first electrical terminal within the reflective recessed cavity; a second electrical terminal within the reflective recessed cavity, the second electrical terminal in electrical proximity to the first electrical terminal; a power supply in electrical flow communication with the first electrical terminal to provide a high voltage current to the first electrical terminal in order to create an arc between the first electrical terminal and the second electrical terminal, so as to generate a shock wave; and a trigger circuit having a conductive element disposed in electrical proximity to the first and second electrical terminals to initiate arc generation.
- 13. The packaging machine in accordance with claim 13 wherein the defoaming device further comprises a protective shield about the body.
- 14. The packaging machine in accordance with claim 12 wherein the defoaming device further comprises a protective screen placed at an opening to the recessed cavity.
- 15. The packaging machine in accordance with claim 12 further comprising a pre-folding station for pre-folding the top panels of each carton prior to sealing.
- 16. The packaging machine in accordance with claim 12 wherein the perimeter of the recessed cavity encompasses two cartons for simultaneous defoaming.
- 17. The packaging machine in accordance with claim 12 including a sound guide disposed between the defoaming device body and the filled carton, the sound guide configured to direct the shock wave about the filled carton.
- 18. An apparatus for defoaming a foamable product dispersed into a container, the defoaming apparatus comprising:a body having a reflective recessed cavity, the body positioned over the container; a first electrical terminal within the reflective recessed cavity; a second electrical terminal within the reflective recessed cavity, the second electrical terminal in electrical proximity to the first electrical terminal; and a step-up transformer for creating a high voltage current from a standard voltage current in electrical flow communication with the first electrical terminal to provide a high voltage current to the first electrical terminal in order to create an arc between the first electrical terminal and the second electrical terminal, so as to create a shock wave, and including a trigger circuit having a conductive element disposed in electrical proximity to the first and second electrical terminals to initiate arc generation.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/US99/15384 |
|
WO |
00 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO00/02781 |
1/20/2000 |
WO |
A |
US Referenced Citations (16)