U.S. patent number 3,825,408 [Application Number 05/395,024] was granted by the patent office on 1974-07-23 for hot air heater for carton sealing machine.
This patent grant is currently assigned to Phillips Petroleum Company. Invention is credited to Silvio T. Farfaglia, Robert G. Halpin.
United States Patent |
3,825,408 |
Farfaglia , et al. |
July 23, 1974 |
HOT AIR HEATER FOR CARTON SEALING MACHINE
Abstract
In a machine for filling and sealing cartons such as the
thermo-plastic coated paperboard milk cartons, the heater head for
heating the upper portion of the carton prior to sealing comprises
a first hot air plenum chamber which enters the open end of the
carton and has a continuous outer perforated wall facing the inner
surface of the carton and a second hot air plenum chamber which
surrounds the outside of the upper end of the carton and has a
continuous inner perforated wall facing the outside surface of the
carton. The outer wall of the first plenum chamber and the inner
wall of the second plenum chamber form a continuous annular space
for receiving the top marginal portion of a carton, with the
perforations in both walls being spaced to provide heating of both
the inner surface and the outer surface of the full extent of the
top marginal portion of the carton. The outer wall of the first
plenum chamber and the inner wall of the outer plenum chamber
extend downwardly and outwardly away from the central vertical axis
of the carton while the inner wall of the second plenum chamber
extends downwardly and outwardly with respect to the central
vertical axis of the carton.
Inventors: |
Farfaglia; Silvio T. (Fulton,
NY), Halpin; Robert G. (Minetto, NY) |
Assignee: |
Phillips Petroleum Company
(Bartlesville, OK)
|
Family
ID: |
23561384 |
Appl.
No.: |
05/395,024 |
Filed: |
September 7, 1973 |
Current U.S.
Class: |
432/230; 34/105;
156/497; 34/104; 53/370.9; 156/498; 493/134 |
Current CPC
Class: |
B29B
13/025 (20130101); B29C 66/43122 (20130101); B29C
66/72328 (20130101); B29C 66/80 (20130101); B29C
66/849 (20130101); B29C 65/103 (20130101); B29C
66/1122 (20130101); B29C 66/73921 (20130101); B29C
66/43121 (20130101); B65B 51/20 (20130101); B29K
2023/06 (20130101); B29C 66/71 (20130101); B29C
66/8167 (20130101); B29L 2031/7166 (20130101); B29C
66/71 (20130101) |
Current International
Class: |
B65B
51/20 (20060101); F23d 003/00 () |
Field of
Search: |
;432/230 ;53/183
;93/DIG.1,44.1R ;156/497,498 ;34/104,105 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Camby; John J.
Claims
What is claimed is:
1. In a machine for filling and sealing gable top cartons formed
from thermoplastic coated paperboard, a heating head for heating
the ridge panels of a filled carton prior to sealing said filled
carton, the score lines in the gable top carton forming structure
of said carton having been broken to form the six ridge panels
thereof into a six sided opening, which comprises a support base,
means attached to a central portion of the lower surface of said
support base to define a central plenum chamber having a continuous
outer perforated wall which has six sections corresponding to the
six sides of said opening in said carton, means attached to the
peripheral portion of the lower surface of said support base to
define an outer annular plenum chamber having a continuous inner
perforated wall with six sections corresponding to the six sides of
said opening, said outer wall of said central plenum chamber and
said inner wall of said outer plenum chamber forming an annular
space adapted to receive therein the ridge panels of a prebroken
gable top structure of a filled carton without contact between the
carton and the heating head, means for introducing heated gas into
said central plenum chamber and into said outer plenum chamber,
said outer wall of said central plenum chamber having perforations
therethrough spaced at intervals along the length of each of the
six sections thereof for directing jets of heated gas at the inner
surface of each of the six ridge panels of the carton being heated,
said outer wall of said central plenum chamber being inclined
downwardly from said support base and outwardly away from the
vertical axis of the carton being heated so that said jets of
heated gas strike the inner surfaces of said ridge panels at acute
angles and are deflected upwardly out of the carton.
2. Apparatus in accordance with claim 1 wherein said inner wall of
said outer plenum chamber is inclined downwardly from said support
base and outwardly from the vertical axis of the carton being
heated so that said inner wall of said outer plenum chamber and
said outer wall of said inner plenum chamber are at least generally
parallel to each other.
3. Apparatus in accordance with claim 2 wherein said inner wall of
said outer plenum chamber has perforations therethrough spaced at
intervals along the length of each of the six sections thereof for
directing jets of heated gas at the outer surface of each of the
six ridge panels of the carton being heated so that the jets of
heated gas from said outer plenum chamber strike the outer surface
of said six ridge panels at acute angles and are deflected
downwardly.
4. Apparatus in accordance with claim 3 wherein a first one and a
second one of the six sections of said inner wall of said outer
plenum chamber are parallel to each other, a third one and a fourth
one of the six sections of said inner wall of said outer plenum
chamber are joined together between a first pair of adjacent ends
of said first one and said second one to form a V having the apex
thereof directed toward the central vertical axis of the carton
being heated, a fifth one and a sixth one of the six sections of
said inner wall of said outer plenum chamber are joined together
between a second pair of adjacent ends of said first one and said
second one to form a V having the apex thereof directed toward the
central vertical axis of the carton being heated, said outer plenum
chamber having a continuous outer wall with four connected
sections, a first one and a second one of said four sections being
parallel to said first one and second one sections of said six
sections of said inner wall of said outer plenum chamber, a third
one of said four sections together with said third one and fourth
one of said six sections of said inner wall of said outer plenum
chamber forming a first generally triangular chamber, a fourth one
of said four sections together with said fifth one and sixth one of
said six sections of said inner wall of said outer plenum chamber
forming a second generally triangular chamber, and wherein said
means for introducing heated gas into said outer plenum chamber
comprises first means for introducing heated gas into said first
triangular chamber and second means for introducing heated gas into
said second triangular chamber.
5. Apparatus in accordance with claim 4 further comprising a first
partition wall extending from said first section of said inner wall
of said outer plenum chamber to the adjacent one of said first and
second sections of the outer wall of said outer plenum chamber, and
a second partition wall extending from said second section of said
inner wall of said outer plenum chamber to the adjacent one of said
first and second sections of the outer wall of said outer plenum
chamber to thereby divide the outer plenum chamber into two
separate chambers.
6. Apparatus in accordance with claim 5 wherein the outer wall of
said central plenum chamber is inclined at an angle to the vertical
in the range of about 10.degree. to about 30.degree..
7. Apparatus in accordance with claim 1 wherein said inner wall of
said outer plenum chamber has perforations therethrough spaced at
intervals along the length of each of the six sections thereof for
directing jets of heated gas at the outer surface of each of the
six ridge panels of the carbon being heated so that the jets of
heated gas from said outer plenum chamber strike the outer surface
of said six ridge panels at acute angles and are deflected
downwardly.
8. Apparatus in accordance with claim 1 wherein a first one and a
second one of the six sections of said inner wall of said outer
plenum chamber are parallel to each other, a third one and a fourth
one of the six sections of said inner wall of said outer plenum
chamber are joined together between a first pair of adjacent ends
of said first one and said second one to form a V having the apex
thereof directed toward the central vertical axis of the carton
being heated, a fifth one and a sixth one of the six sections of
said inner wall of said outer plenum chamber are joined together
between a second pair of adjacent ends of said first one and said
second one to form a V having the apex thereof directed toward the
central vertical axis of the carton being heated, said outer plenum
chamber having a continuous outer wall with four connected
sections, a first one and a second one of said four sections being
parallel to said first one and second one sections of said six
sections of said inner wall of said outer plenum chamber, a third
one of said four sections together with said third one and fourth
one of said six sections of said inner wall of said outer plenum
chamber forming a first generally triangular chamber, a fourth one
of said four sections together with said fifth one and sixth one of
said six sections of said inner wall of said outer plenum chamber
forming a second generally triangular chamber, and wherein said
means for introducing heated gas into said outer plenum chamber
comprises first means for introducing heated gas into said first
triangular chamber and second means for introducing heated gas into
said second triangular chamber.
9. Apparatus in accordance with claim 8 further comprising a first
partition wall extending from said first section of said inner wall
of said outer plenum chamber to the adjacent one of said first and
second sections of the outer wall of said outer plenum chamber, and
a second partition wall extending from said second section of said
inner wall of said outer plenum chamber to the adjacent one of said
first and second sections of the outer wall of said outer plenum
chamber to thereby divide said outer plenum chamber into two
separate chambers.
10. Apparatus in accordance with claim 1 wherein the outer wall of
said central plenum chamber is inclined at an angle to the vertical
in the range of about 10.degree. to about 30.degree..
Description
This invention relates to method and apparatus for heating the end
of a carton prior to sealing the carton.
Hot air heater heads for gable top carton sealing machines having
an inner plenum chamber which fits within the open end of the
carton and two outside plenum chambers for heating portions of the
outside of the carton are known. However, difficulties in achieving
a liquid tight seal with this type of heater has been encountered.
It is an object of the present invention to provide a new and
improved hot air heater head. Another object of the invention is to
improve the quality of the seals for carton ends. Another object of
the invention is to improve the seals in the top end of a gable top
carton. Yet another object of the invention is to reduce the time
required for heating the open end of a gable top carton to a
suitable bonding temperature. Still another object of the invention
is to minimize faulty seals in a carton due to contamination by the
product being packaged.
Other objects, aspects and advantages of the invention will be
apparent from a study of the specification, the drawings and the
appended claims to the invention.
In the drawings,
FIG. 1 is a front elevational view of a carton forming, filling and
sealing machine embodying the present invention;
FIG. 2 is a simplified elevational view of a carton top heating
station suitable for use in the machine of FIG. 1;
FIG. 3 is a top plan view of the heater head structure for the top
heating station of FIG. 2;
FIG. 4 is an elevational view in cross section taken along line
4--4 in FIG. 3;
FIG. 5 is an elevational view in cross section taken along line
5--5 in FIG. 3, omitting the container; and
FIG. 6 is a cross-sectional view taken along line 6--6 of FIG.
5.
Referring now to the drawings in detail and to FIG. 1 in
particular, the carton forming, filling and sealing machine
comprises a forming section 11 and a filling and sealing section
12. The forming section 11 comprises a sidewall blank feeding and
heating subsection 13, a bottom blank feeding and heating
subsection 14, a forming subsection 15, and a transfer subsection
16. The filling and sealing section has two parallel endless
conveyor systems 17, and each conveyor system comprises a filling
subsection 18 occupying five conveyor stations, a defoaming station
19, a score breaking station 20, a top heating station 21, a
folding and sealing station 22, a secondary sealing station 23, a
branding station 24, and a transfer station 25.
The sidewall blanks 31 manually placed in the sidewall blank
magazine 32 are flat, single sheets of paperboard, rectangular in
shape, scored to provide five longitudinal panels and a gable-top
structure, and coated on both the top and bottom surfaces of each
sheet with a thermoplastic material, e.g., polyethylene. The
sidewall blanks 31 are successively withdrawn from magazine 32 and
intermittently advanced through the sidewall blank heating station
33 to the sidewall blank receiving station 34 for turret 35. At the
sidewall blank heating station 33, the side margins to be
overlapped and the bottom margin of the sidewall blank are heated
to a bonding temperature for the thermoplastic coating.
The turret 35 is journalled on a horizontal axis and carries eight
circumferentially spaced apart mandrels 36 extending radially from
the axis of turret 35. The cross section of each of mandrels 36 in
a plane perpendicular to its longitudinal axis is generally
rectangular. Suitable drive mechanism is provided for indexing or
effecting intermittent rotation of the turret 35 to move each
mandrel from the sidewall blank receiving station 34 through a
blank folding station 37; a bottom end closure forming, applying
and sealing station 38; a secondary bottom sealing station 39; a
stripping station 40; and three successive nonoperating stations
41, 42 and 43.
The tubular carton body having a bottom closure sealed thereto is
removed from the mandrel 36 at the stripping station 40 and is
transferred to a conveyor pocket 45 of one of the two conveyor
systems 17. The product to be packaged is introduced into the
open-topped tubular carton in the filling subsection 18. If
desired, any foam resulting from the filling operation can be
removed at defoaming station 19. The scores for the gable-top
structure can be initially folded in the score breaking station 20,
resulting in the conventional six-sided top structure. The
gable-top ridge panels of the carton are heated in station 21 to a
temperature at least as high as the thermal bonding temperature of
the thermoplastic coatings on the carton. The heated superstructure
is then folded into contact under pressure at the folding and
sealing station 22 to effect the bonding of adjacent ridge panels.
Secondary sealing station 23 applies pressure to the ridge panels
during cooling of the thermoplastic bond. If desired, a data
indicia, plant identification or other information can be applied
to the bonded ridge panels of the sealed carton at branding station
24. The formed, filled and sealed carton is removed from its
conveyor pocket 45 at the transfer station 25 and placed on a
delivery conveyor 46.
Referring now to FIGS. 2-6, a filled container 51, having had the
gable-top score lines broken so that the six ridge panels have
assumed the six sided configuration is positioned in its conveyor
pocket 45 at the top heating station 21. The heater head 52 for
heating the ridge panels is shown in the down position,
encompassing the ridge panels of the gable-top structure of
container 51. Air under pressure is supplied through conduit 53 to
the inlet of electrical heater 54. The heated air passes through
conduit 55 to the inlet of heater head 52. While air is the
presently preferred heating gas, other gases may be employed
instead of air.
The heater head 52 comprises a horizontal base plate 61 to which
cylindrical bar 62 and vertical plates 63, 64 and 65 are secured by
suitable means, for example by welding. The upper portion of bar 62
has a large diameter bore 66 formed therein to receive the heated
air from heater 54. The upper end of bar 62 is provided with
external threads 67 to facilitate the connection thereof to conduit
55. A secondary central base plate 68 having a six-sided
configuration corresponding to and slightly smaller than the
six-sided configuration of the ridge panels of the gable-top
structure is secured to the lowerside of the central portion of
base plate 61. An outer secondary base plate 69 having a six-sided
opening therein corresponding to and slightly larger than the
six-sided configuration of the ridge panels is secured to the
periphery of base plate 61 to form a continuous channel 71 between
central plate 68 and outer plate 69 adapted to receive the upper
edge of the ridge panels of the container 51. If desired channel 71
can be omitted, and plates 68 and 69 can be formed as a single
element. Plates 68 and 69 can also be formed with plate 61 as a
single piece. A central plenum chamber 72 is formed by bottom wall
73 and sidewall sections 74, 75, 76, 77, 78 and 79, together with
secondary central base plate 68. A passage 80 extends through the
lower portion of rod 62, base plate 61 and secondary central base
plate 68 to provide fluid communication between bore 66 and plenum
chamber 72. An outer annular plenum chamber comprising first and
second compartments 81 and 82 is formed by outer wall sections 83,
84, 85 and 86, inner wall sections 87, 88, 89, 90, 91, and 92,
together with secondary outer base plate 69, and bottom walls 95
and 96. In one embodiment the outer annular chamber is divided into
two separate compartments by partitions 93 and 94. A passageway 97
extends through rod 62, plate 63, and base plate 61 into opening 98
in secondary outer base plate 69 to provide fluid communication
between bore 66 and compartment 81. A passageway 99 extends through
rod 62, plate 64, and base plate 61 into opening 101 in secondary
outer base plate 69 to provide fluid communication between bore 66
and compartment 82.
The continuous outer sidewall of the central plenum chamber 72
formed by sidewall sections 74, 75, 76, 77, 78 and 79 corresponds
to the six-sided opening formed by the six ridge panels of the
container 51, but is slightly smaller in dimensions so that the
central plenum chamber 72 can enter the carton opening without
contact between the carton and the heater head 52 occurring.
Sidewall sections 75 and 78 extend along horizontal lines parallel
to each other and to the horizontal lines of the ridge panels
surmounting the roof panels of the gable top structure of carton
51. Sidewall sections 75 and 79 are joined together between one end
of section 75 and the adjacent end of section 78 to form a V having
the apex thereof directed toward the central vertical axis of the
carton 51 being heated. Similarly, sidewall sections 76 and 77 are
joined together between the other adjacent pair of ends of sections
75 and 78 to form a second V having the apex thereof directed
toward the central vertical axis of the carton 51 being heated. The
sidewall sections 74, 75, 76, 78 and 79 are inclined to the
vertical so that they extend downwardly from secondary central base
plate 68 and outwardly away from the central vertical axis of
container 51 and heater head 52. An angle of inclination to the
vertical for sections 74-79 in the range of about 10.degree. to
about 30.degree. is satisfactory, with an angle of inclination in
the range of about 15.degree. to about 25.degree. being
preferred.
The outer wall of the central plenum chamber 72 is provided with
perforations 102 therethrough spaced at intervals along the length
of each of the six sidewall sections 74-79 for directing jets of
heated air at the inner surface of each of the six ridge panels of
the carton 51 being heated. The inclination of the outer sidewall
formed by section 74-79 and the inclination of the inner surface of
the ridge panels of carton 51 are such that the jets of heated gas
strike the inner surface of the ridge panels at acute angles and
are deflected upwardly out of the carton 51. The upward direction
of these jets minimizes the heating of the product being packaged
in carton 51. The upward flow of the heated gas along the inside
surface of the ridge panels aids in cleaning the inner surface of
the ridge panels of any particles or droplets of the material being
packaged, thereby minimizing defective sealing of the ridge panels
due to the presence of material which would interfere with the
effectiveness of the seal. The heated air escapes from the interior
of the carton 51 by moving upwardly through the space between the
outer sidewall of plenum chamber 72 and the carton ridge
panels.
The continuous inner wall of the outer plenum chamber formed by the
six sidewall sections 87, 88, 89, 90, 91 and 92 also corresponds to
the six sided opening formed by the six ridge panels of the
container 51, but is slightly larger in dimensions so that the
inner wall of the plenum chamber and the outer wall of the inner
plenum chamber 72 form an annular space into which the ridge panels
of the carton 51 can extend without contacting the heater head 52.
The sidewall sections 88 and 86 extend along horizontal lines
parallel to the horizontal lines of sidewall sections 75 and 78.
Sections 87 and 92 are joined together between one pair of adjacent
ends of sections 86 and 88 to form a V having the apex thereof
directed toward the central vertical axis of the carton 51 being
heated. Similarly, sidewall sections 89 and 90 are joined together
between the other pair of adjacent ends of sections 86 and 88 to
form a V having the apex thereof directed toward the central
vertical axis of carton 51. Sidewall sections 83, 84, 86, 87, 88,
91 and 92 form a generally triangular chamber 81 having parallel
wing chambers extending from opposite ends thereof. Similarly
sidewall sections 84, 85, 86, 88, 89, 90 and 91 form a second
generally triangular chamber 82 having parallel wing chambers
extending from the opposite corners. This configuration is
advantageous in the distribution of the heated gas to the various
perforations.
The sidewall sections 87-92 are inclined to the vertical so that
they extend downwardly from secondary base plate 69 and outwardly
away from the central vertical axis of container 51 and heater head
52. The angle of inclination to the vertical for the sidewall
sections 87-92 will generally be in the range of about 5.degree. to
about 50.degree. and preferably will be in the range of about
15.degree. to about 30.degree.. The inner wall of the annular
plenum chamber 81, 82 is provided with perforations 103
therethrough spaced at intervals along the length of each of the
six sidewall sections 87-92 for directed jets of heated gas at the
outer surface of each of the six ridge panels of the carton 51
being heated. These jets strike the outer surface of the ridge
panels at acute angles and are deflected downwardly away from the
top edge of the carton 51. The downward flow of heated gas along
the outer surface of the ridge panels cleans this surface of any
foreign material such as particles or droplets of the material
being packaged. This cleaning action is very advantageous in the
formation of the bond between the outside surfaces of the pair of
adjacent ridge panels over each enfolded portion of the gable
structure. Heating the outside surfaces of all of the ridge panels
gives a more uniform temperature of the coated surfaces to be
bonded and reduces the time required for heating. Directing jets of
heated gas at the external surfaces of all of the ridge panels also
avoids deformation of the open end of the carton due to uneven
pressures, thereby minimizing the possibility of contact between
the carton and the heater head.
The bracket 104 is secured to flange 65 by suitable means. Bracket
104 is provided with a plate 105 which fits within a guideway to
provide horizontal stability of the heater head 52 as it is
vertically reciprocated. Suitable linkage means, not shown,
connects bracket 104 to the drive mechanism of the machine to lower
heating head 51 to enclose the ridge panels of a carton after the
carton has been indexed to top heating station 21. After the
thermoplastic coatings on the ridge panels are heated to a tacky
condition, bracket 104 is powered to raise the heating head 52,
permitting the heated carton to be indexed to sealing station
22.
Reasonable variations and modifications are possible within the
scope of the foregoing disclosure, the drawings and the appended
claims to the invention.
* * * * *