In-line fitment sealing apparatus and method

Dual lanes of fitment-sealing apparatus, for sealing plastic spout fitments to carton blanks, are integrated in line with conventional form/fill/seal production lines. Each apparatus includes a carton blank supply, an indexing conveyor for advancing the blanks in tube form to a sealing station, a gravity-feed track for supplying fitments to the sealing station through an escapement, a pair of fitment retaining clamps for holding the fitment in registration with a spout hole cut in the carton blank, an anvil which is inserted inside the carton blank, a sealing head which is moved to press the fitment in contact with and to seal it to an extrusion layer on the external side of the carton blank, and a timing control for synchronizing the movements of the parts and advancing the carton blanks through the sealing station to an output thereof. The fitment may also be sealed to the extrusion layer with a hot-melt adhesive applied to the fitment just prior to pressing against the carton blank. Heat may be applied to tackify the adhesive by a hot anvil or sealing head equipped with heating elements.

TECHNICAL FIELD 
This invention generally relates to apparatus and method for sealing 
fitments to paperboard cartons, and, more particularly, of the type which 
can be used for operation in line with conventional carton form/fill/seal 
machinery. 
BACKGROUND ART 
Conventional paperboard cartons for packaging milk, juice, and other 
beverage products are typically formed from a paperboard blank assembled 
in a rectangular open-ended configuration, which is then filled with the 
liquid contents and sealed with a gable or flat-folded top. The carton 
forming, filling, and sealing is done under sanitary conditions in lines 
of so-called "form/fill/seal" machinery. The industry has developed 
reclosable spouts for such cartons, typically in the form of plastic spout 
fitments which are sealed to the top end of the cartons. Examples of 
hinged-type spout fitments are shown in commonly-owned U.S. Pat. Nos. 
4,705,197 and 4,770,325, both to Gordon and Kalberer. Other types of spout 
fitments include pull-open nozzles and screw caps. These reclosable spouts 
allow the cartons to be more easily opened and reclosed without leaking. 
The plastic spout fitments are typically attached to the paperboard blanks 
by sealing a flange portion of the fitment to a heat-sealable coating or 
extrusion layer on the paperboard, by means of adhesives, heat sealing, or 
sealing with an ultrasonic horn. The attachment step requires an 
intermittent certain dwell time for aligning each fitment in position on a 
carton and applying the required adhesive, heat, or ultrasonic energy to 
the portion to be sealed. An example of indexing machinery for precise 
registration and sealing of fitments to cartons is shown in commonly-owned 
U.S. Pat. No. 4,846,915 of Keeler, Bombolevich and Sinocchi. 
As reclosable spout fitments have come into widespread use, recent 
developments have been made in fitment sealing apparatus which synchronize 
the intermittent fitment sealing step with a continuous conveyor line used 
to supply cartons to form/fill/seal machinery. Examples of such fitment 
sealing apparatus are shown in copending, commonly-owned U.S. patent 
applications Ser. No. 07/594,536 of Keeler and Bombolevich, entitled 
"Apparatus For Continuous Feeding And Synchronized Application of Fitments 
To Carton Blanks And Related Method", and Ser. No. 07/571,811 of Keeler, 
entitled "System For Continuous High Speed Application of Fitments To 
Carton Blanks And Related Method", both of which are incorporated herein 
by reference. In these examples, the fitments are formed with a flat shape 
and are supplied to the fitment sealing station from a web or roll. 
It is also desirable to apply three-dimensionally shaped spouts, e.g. 
plastic pull-open nozzles or screw caps, to the cartons at high speed in 
order to supply a continuous line of fitted cartons to a form/fill/seal 
machine. One proposal for such an apparatus is shown in U.S. Pat. No. 
4,788,811 of Kawajiri, Honda and Furukawa. The Kawajiri et al. sealing 
apparatus includes a suction holder which retrieves a three-dimensional 
cap fitment from the end of a supply chute, moves the fitment axially 
inside a carton blank assembled in rectangular tube configuration, inserts 
the spout portion of the fitment laterally through a hole die-cut in the 
carton wall, and holds the flange portion of the fitment against the 
heat-sealable coating on the internal side of the carton while an 
ultrasonic horn is advanced on the external side. This apparatus, however, 
has the problem that the complex movements required of the cap holder 
limit the speed at which the machinery can be operated, and, further, has 
a significant risk of mechanical breakdown or misalignment of the fitment. 
SUMMARY OF INVENTION 
It is therefore a principal object of the invention to provide an apparatus 
and method for sealing plastic spout fitments to paperboard blanks in a 
continuous mode of operation, i.e., for supplying a continuous line of 
fitted cartons to a form/fill/seal machine. It is a particular object that 
such apparatus and method be capable of applying three-dimensional cap 
fitments on cartons with a high degree of precision and efficiency. It is 
a further object that such apparatus be constructed so that the moving 
elements thereof execute limited mechanical movements and/or functions, in 
order to assure a high degree of reliability and reduce the risk of 
mechanical failure. 
In accordance with the invention, a fitment sealing apparatus comprises: 
carton supply means for supplying a series of carton blanks, each having a 
wall defining at least an open top end thereof, a spout hole cut through 
the carton wall at a selected spout position in the vicinity of the open 
top end, and an extrusion layer applied on at least an external side of 
the carton wall around the spout hole; advancing means for intermittently 
advancing each one of the series of carton blanks in turn to a sealing 
station; fitment supply means for supplying a series of fitments to said 
sealing station; escapement means for intermittently releasing each 
fitment in turn from said fitment supply means; fitment retaining means 
for receiving each fitment released from said escapement means and for 
positioning it in registration with the spout hole on the external side of 
the wall of a carton blank advanced to said sealing station; anvil means 
movable into the open top end adjacent the spout position on an internal 
side of the wall of a carton at said sealing station; anvil moving means 
for intermittently moving and retracting said anvil means into and from 
the open top end of a carton blank advanced to said sealing station; 
sealing means movable for pressing a fitment positioned by said fitment 
retaining means in contact with the extrusion layer on the external side 
of the wall of a carton blank at said sealing station, and also indirectly 
against said anvil means on the internal side thereof, and for sealing the 
fitment to the carton blank in registration with the spout hole; sealing 
moving means for intermittently moving and retracting said sealing means 
to and from the carton blank in timed relation with said anvil moving 
means; releasing means for allowing the fitment to be released from said 
fitment retaining means in conjunction with movement of said sealing means 
to press and seal the fitment to a carton blank at said sealing station; 
and output means for advancing each carton blank fitted with a respective 
fitment from said sealing station to an output end of the apparatus. The 
invention includes the related method and product of performing the 
fitment sealing. 
In a preferred embodiment, a pair of fitment sealing stations are provided 
in a dual-lane system each operated at a speed of 60 sealing operations 
per minute. Pre-sided carton blanks are opened in a tube configuration and 
placed in flight pockets on an indexing conveyor by a reciprocating placer 
for step-wise transport to each fitment sealing station. At the sealing 
station, a three-dimensional cap fitment is gravity-fed down a conveyor 
track and released by an escapement to a pair of fitment retaining clamps 
positioned in front of the spout hole of a carton blank advanced to the 
sealing station. A timing control causes the retaining clamps to move 
apart at the same time as an ultrasonic sealing horn advances to press the 
fitment in contact with the external extrusion layer on the carton blank 
and an anvil is inserted on the inside of the carton blank. 
The horn is energized to seal the fitment to the carton blank, the horn and 
anvil are then retracted, and the retaining clamps are moved back in 
position to receive the next fitment. The semi-finished carton blank is 
then advanced to an output from the sealing station, where it can then be 
supplied to a bottom-forming index wheel and a continuous content-filling 
and top-sealing production line. In an alternative embodiment, the fitment 
is sealed to the extrusion layer with a hot-melt adhesive. The adhesive is 
applied to the sealing surface of the fitment just prior to pressing the 
fitment surface against the carton substrate. Heat may be applied to 
tackify the adhesive by a hot anvil or sealing head equipped with heating 
elements. 
Other objects, features, and advantages of the present invention will 
become apparent from the following detailed description of the best mode 
of practicing the invention when considered with reference to the 
drawings, of which:

DETAILED DESCRIPTION OF INVENTION 
Referring to FIGS. 1 and 2, a spout fitment 15 is shown sealed to a carton 
blank 10 for use as a gable top container. In FIG. 1, the carton blank 10 
is scored and formed into a hollow rectangular tube configuration in a 
conventional manner. The carton blank 10 is held by a seam 11 formed by 
sealing an edge flap of one lateral wall to the adjacent lateral wall. The 
upper walls of the carton blank 10 define an open top end of the carton 
and are shown with score lines 12 along which the upper walls 13 will 
later be folded to form a gable top. Alternatively, the top end may be 
folded down in a flat configuration to form a flat container top. One of 
the upper walls 13 has a spout hole 14 die-cut through the paperboard 
layer, and the spout fitment 15 is sealed to the carton wall in 
registration with the spout hole to allow the liquid contents of the 
container to be poured therethrough. 
The spout fitment may be of any type, although the advantages of the 
fitment sealing capabilities of the invention are best illustrated with a 
fitment having a three-dimensional shape, such as a pull-open nozzle or 
screw cap type of spout. As shown illustratively in FIG. 2, a screw cap 
fitment is made of a plastic material by injection molding. The screw cap 
has a flange/base part 15a, and a cap part 15b which screws on and off the 
flange/base part 15a by means of complementary threads 16a, 16b. The 
carton wall 13 includes a substrate layer 13a, and extrusion layers 13b, 
13c of a thermoplastic resin material on the external and internal 
surfaces of the carton wall. In the preferred mode of the invention, the 
flange portion 15c of the flange/base part 15a is sealed to the external 
extrusion layer 13b of the carton wall with the pour hole 15d of the cap 
fitment 15 aligned in registration with the spout hole 14. 
Preferably, the spout hole 14 is die cut through the substrate layer 13a, 
then the extrusion layers 13b, 13c are applied on both sides over the 
spout hole. This approach seals the hole and allows the hermetic 
conditions of the container to be maintained during and after the 
form/fill/seal production process and for distribution and stocking of the 
product containers. The extrusion layers also serve as a tamper-proof 
measure for consumer safety. The spout hole is opened by the consumer, 
e.g., by piercing through the extrusion layers with a straw. 
The carton blank may be of any type used for hermetically-sealed drink 
containers and for various sizes, such as pint, quart, one-liter, 
half-gallon, and two-liter containers. The advantages of the fitment 
sealing apparatus of the invention are best illustrated for paperboard 
containers of the type used in a continuous conveyor line to a carton 
form/fill/seal machine, as described for the preferred embodiment herein. 
In FIG. 3, dual fitment sealing lines 20a, 20b are shown in line with 
respective form/fill/seal production lines 30a, 30b. The form/fill/seal 
lines preferably operate in the range of 40 to 60 sealing operations per 
minute. The lines each require a continuous input of cartons from the 
respective sealing lines ready to be formed with a bottom end, filled with 
liquid contents, and sealed at the top end. Each of the fitment sealing 
lines 20a, 20b includes: a carton supply 21 for supplying a series of 
carton blanks 10 in rectangular tube form, each having the spout hole cut 
through the carton wall at a selected spout position in the vicinity of 
the open top end; an indexing conveyor 22 for intermittently advancing the 
carton blanks in turn to a sealing station 23; a fitment supply track 24 
for supplying a series of fitments to the sealing station 23 through an 
escapement gate 25; a fitment retaining mechanism 26 for receiving the 
fitment released from the escapement gate and positioning it in 
registration with the spout hole in the carton blank at the sealing 
station 23; an anvil 27 movable into the open top end inside the carton 
adjacent the spout hole position; and a sealing head 28 which is moved to 
press the fitment in contact with the extrusion layer on the carton wall 
and against the anvil 27 inside the carton blank. A further support member 
27a may be provided between the sealing stations of the two lines to 
absorb the offsetting impacts of the sealing heads 28. From the sealing 
station 23, the carton fitted with the spout fitment is advanced by the 
indexing conveyor 22 to an output end where the carton blanks are 
transferred to the form/fill/seal line. 
In FIGS. 4A and 4B, the preferred embodiment is shown in greater detail. 
Pre-seamed carton blanks 10 are supplied from the carton supply 21. The 
carton blanks are opened to form a hollow tube and moved to the indexing 
conveyor 22 by a reciprocating placer 29a. The indexing conveyor 22 has a 
number of carton-holding pockets 22a supported thereon which are advanced 
in step-wise fashion to receive carton blanks 10 from the reciprocating 
placer 29a, hold the carton blanks at the sealing station 23, and advance 
the semi-finished carton blanks to the output end. 
From the output end, a reciprocating placer 29b transfers the semi-finished 
carton blanks onto the spokes of an indexing wheel 31 on which the bottom 
ends are formed and sealed by bottom-forming member 32. The cartons are 
transferred from the indexing wheel 31 to a continuous line conveyor 34 on 
which they are moved through a liquid-filling and top-end sealing station 
33. The general construction and operation of the form/fill/seal machine 
for high-speed production of liquid-container products are well known in 
the industry and are not described further herein. 
At the sealing station 23, a three-dimensional spout cap fitment 15 is 
gravity-fed down the feed track 24 and released by the escapement gate 25 
to a pair of fitment retaining clamps 26a positioned in front of the spout 
hole 14 of the carton blank 10 advanced to the sealing station 23. The 
retaining clamps 26a have a bevelled surface 26b along which the fitment 
cap portion 15b slides down to the precise position in front of the spout 
hole 14. The retaining clamps 26a are held by brackets 26c to the ends of 
pistons driven by a cylinder 26d. A timing control actuates the cylinder 
26d to cause the retaining clamps 26a to move apart to a position clear of 
the fitment, at the same time as the sealing head 28 advances to press the 
fitment in contact with the external extrusion layer on the carton blank 
and the anvil 27 is inserted inside the carton blank 10. The sealing head 
28 and/or anvil 27 is energized by the timing control to seal the fitment 
15 to the carton blank 10, the sealing head 28 and anvil 27 are then 
retracted, and the retaining clamps 26a are moved back in position to 
receive the next fitment. 
The relative positions of the fitment-handling parts are shown more clearly 
in FIGS. 5 and 6. The anvil 27 is inserted in the open top end of the 
carton blank 10 in line between the support member 27a and the movement of 
the sealing head 28 against fitment 15. The anvil 27 has a shape 
corresponding approximately to the internal confines of the carton blank 
with rounded edges to avoid catching on the carton. In the preferred mode, 
the sealing head is an ultrasonic horn which radiates short-range 
ultrasound energy to heat and fuse the flange portion of the fitment 15 to 
the external extrusion layer of the carton blank. The ultrasonic horn is 
advanced and retracted under timing control of its driving cylinder 28a. 
Similarly, the anvil 27 is inserted and retracted under timing control of 
its driving cylinder 27b. The anvil may also have heating elements which 
are energized to apply heat to the extrusion layer through the carton 
wall. 
In FIG. 7, an example of the timing control is illustrated for the anvil 
27, indexing conveyor 22, ultrasonic horn 28, and fitment retaining clamps 
26a. One complete cycle for a carton blank takes 0.1 second. During the 
first 0.04 second of the cycle, the indexing conveyor is moving, while the 
anvil and horn are retracted and the fitment clamps are in the closed 
(holding) position. During the latter 0.6 second of the cycle, the 
indexing conveyor is halted in a dwell state, the anvil is inserted, the 
horn is advanced to the sealing position and energized, and the fitment 
clamps are simultaneously moved to the opened position. With this example, 
semi-finished cartons blanks are output from the sealing station at the 
rate of 60 per minute, which is sufficient to allow it to be synchronized 
with a conventional form/fill/seal production line. 
In FIG. 8, an alternative embodiment is shown in which the fitment 15 is 
sealed to the extrusion layer of the carton blank 10 with a hot-melt 
adhesive. As the fitment is gravity-fed from the track 24 through the 
escapement gate 25, the sealing surface on the rear of the flange portion 
of the fitment 15 is nipped and brushed with hot-melt adhesive by the 
applicator roll 40. The applicator roll is supplied with adhesive in a 
liquid state by the supply roll 41 housed in a reservoir housing 42. 
Alternatively, the adhesive may be applied to the carton blank by 
electronically actutated jet nozzles in a pattern corresponding to the 
shape of the spout hole and the fitment sealing surface. 
The adhesive is applied to the sealing surface of the fitment just prior to 
its entry in the retaining clamps in position in front of the spout hole 
of the carton blank. The sealing head 28 is then advanced to bond the 
fitment to the extrusion layer of the carton blank through the adhesive 
layer applied by the applicator roll 40. Heat may also be applied to 
tackify the adhesive by a hot anvil or sealing head equipped with heating 
elements. A heat controller and sensors are used to maintain the proper 
temperature settings during production. 
In accordance with the invention, the sealing of spout fitments to the 
carton blanks can be achieved at a rate of 60 units/minute or higher, and 
dual lanes can be arranged side-by-side using a common support for the 
movement of the sealing heads from opposite sides thereof. The moving 
elements at the sealing station execute simple mechanical movements so as 
not to limit an increase in production speed or present a risk of 
mechanical failure. Accurate registration of the fitment to the die-cut 
spout hole in the carton is obtained, and a secure seal can be formed with 
a low error rate. The fitment sealing system is simple in design and can 
be assembled at a low cost. Most importantly, the output of the sealing 
station can be synchronized with the input of a conventional 
form/fill/seal production line for the supply of spout-fitted carton 
blanks with a minimum of retrofitting. The ultrasonic sealing of the 
thermoplastic fitment flange to the heat-sealable extrusion layer, or 
alternatively the heat-bonding of the same through a hot-melt adhesive 
layer ensures a fitment seal of complete integrity and reliability. 
Numerous modifications and variations are of course possible given the 
above disclosure of the principles and mode of carrying out the invention. 
It is intended that all such modifications and variations be considered as 
within the spirit and scope of the invention, as defined in the following 
claims.