U.S. patent application number 12/579001 was filed with the patent office on 2010-04-15 for case sealer with integrated hot melt dispensing system.
Invention is credited to DAVID DUCKWORTH, John K. Fornal, Benjamin Onofrei, Hin-Keng Swee.
Application Number | 20100089012 12/579001 |
Document ID | / |
Family ID | 41404577 |
Filed Date | 2010-04-15 |
United States Patent
Application |
20100089012 |
Kind Code |
A1 |
DUCKWORTH; DAVID ; et
al. |
April 15, 2010 |
CASE SEALER WITH INTEGRATED HOT MELT DISPENSING SYSTEM
Abstract
A case sealing system comprising an integrated hot melt
processing, dispensing and application system whereby the bottom
and the top of a filled box are both substantially simultaneously
sealed with a hot melt adhesive.
Inventors: |
DUCKWORTH; DAVID;
(Blackburn, GB) ; Swee; Hin-Keng; (Singapore,
SG) ; Onofrei; Benjamin; (Urbana, IL) ;
Fornal; John K.; (Dunellen, NJ) |
Correspondence
Address: |
Henkel Corporation
10 Finderne Avenue
Bridgewater
NJ
08807
US
|
Family ID: |
41404577 |
Appl. No.: |
12/579001 |
Filed: |
October 14, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61105559 |
Oct 15, 2008 |
|
|
|
Current U.S.
Class: |
53/477 ;
53/376.3 |
Current CPC
Class: |
B65B 51/023 20130101;
B65B 7/20 20130101 |
Class at
Publication: |
53/477 ;
53/376.3 |
International
Class: |
B65B 7/00 20060101
B65B007/00; B65B 51/10 20060101 B65B051/10 |
Claims
1. A case sealer comprising a frame having a longitudinal axis that
includes an entrance conveyor for moving boxes entering the case
sealer along the axis, a pair of longitudinal spaced-apart, lateral
belt drives located to receive boxes from the entrance conveyor and
move them into and out of a hot melt dispensing platform, said hot
melt dispensing platform comprising a floor that is open in the
center, the center being flanked by a pair of peripherally located
angled floor regions that allows the major flaps of the folded box
to drop in order to receive hot melt adhesive, and an integrally
connected hot melt dispensing system comprising a plurality of hot
melt dispensing nozzles, said nozzles being located both above and
below the hot melt dispensing platform.
2. The case sealer of claim 1 wherein the areas of angled floor
have about a 15.degree. downward angle from horizontal.
3. The case sealer of claim 1 comprising a first pair of nozzles
above the sealing platform for applying hot melt adhesive to the
outside surface of each of the closed minor flaps of the top of the
box and a second pair of nozzles located below the sealing platform
for applying hot melt adhesive to the outside surface of the closed
minor flaps of the bottom of the box.
4. The case sealer of claim 1 comprising a first pair of nozzles
above the sealing platform for applying hot melt adhesive to the
outside surface of each of the open major flaps of the top of the
box and a second pair of nozzles located below the sealing platform
for applying hot melt adhesive to the outside surface of the open
major flaps of the bottom of the box.
5. The case sealer of claim 1 wherein the integrally connected hot
melt dispensing system comprises a hot melt adhesive, a melt tank
having a interior cavity adapted to receive said adhesive, and an
automatic dispensing unit integrally connected to the melt
tank.
6. The case sealer of claim 5 wherein the hot melt dispensing
system is programmed to operate at temperatures of about
250.degree. F. or lower.
7. The case sealer of claim 6 wherein the hot melt dispensing
system is programmed to operate at temperatures of about
200.degree. F. or lower.
8. The case sealer of claim 5 wherein the heating chamber of the
hot melt dispensing system is connected to a dispensing pump.
9. The case sealer of claim 10 wherein said means for transporting
said molten adhesive is a heated hose.
10. The case sealer of claim 1 wherein the hot melt dispensing
system comprises an adhesive inlet valve for introducing solid
adhesive into the melt tank.
11. The case sealer of claim 1 wherein the hot melt dispensing
system comprises an adhesive inlet valve for introducing solid
adhesive into the automatic feed chamber.
12. A case sealer comprising an integrated hot melt dispensing
system connected to said case sealer comprising an automatic
dispensing unit for maintaining a supply of said adhesive in its
solid form, a supply passage connected to said dispensing unit for
supplying said adhesive to the interior cavity of said melt tank, a
supply port in communication with the interior cavity of the melt
tank and connected to the supply passage, and a nozzle for
dispensing molten hot melt adhesive.
13. A packaging method comprising constructing the box, closing but
not sealing shut the bottom of the box, filling the box with a
material to be packaged, moving the filled boxes into an area of a
box sealer comprising a pair of spaced-apart lateral drive belts
and hot melt nozzles, moving the box via the drive belt through a
region in which a hot melt dispensing system applies adhesive to
the bottom and top flaps, and closing the flaps whereby the bottom
and top ends of the box become sealed.
14. The method of claim 13 where the hot melt adhesives is
substantially simultaneously applied to the top and bottom
flaps.
15. The method of claim 14 where the adhesive is substantially
simultaneously applied to the top of the box on the outside surface
of the minor flaps and to the bottom of the case on the outside
surface of the minor flaps.
16. The method of claim 15 where the adhesive is a low application
temperature hot melt adhesive.
17. The method of claim 16 wherein the hot melt dispensing system
applies the adhesive at temperature of about 250.degree. F. or
lower.
18. The method of claim 17 wherein the hot melt dispensing system
applies the adhesive at temperature of about 200.degree. F. or
lower.
19. The method of claim 16 herein the hot melt adhesive comprises a
polymer selected from the group consisting of amorphous
polyolefins, ethylene-containing polymers and rubbery block
copolymers, ethylene/vinyl acetate copolymer, isotactic or atactic
polypropylene, styrene-butadiene, styrene-isoprene,
styrene-ethylene-butylene A-B-A or A-B-A-B block copolymers,
ethylene n-butyl acrylate, ethylene vinyl acetate, ethylene vinyl
acetate, tactic polypropylene and mixtures thereof.
20. The method of claim 19 wherein the hot melt adhesive further
comprise a tackifying resins, oils plasticizers, waxes and
additives.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 61/105,559 filed Oct. 15, 2008, the contents
of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to a box or case sealer for closing
the open ends of cardboard boxes or cartons. The case sealer has a
frame with a conveyor for moving filled boxes into a pair of
spaced-apart lateral drive belts that function to convey the box
through a region comprising a hot melt dispensing system that
applies adhesive to the bottom and top flaps in order to allow the
flaps to be sealed shut.
BACKGROUND OF THE INVENTION
[0003] In the packaging industry, many products are packed in
cardboard boxes or cartons for shipping. One end of the box, namely
the bottom, is typically sealed shut with hot melt adhesive or with
tape before the box is filled. Alternatively, the bottom of the box
may be closed, but not sealed shut before the box is filled. After
the box is filled, the end and side flaps of the open top end of
the box are folded inwardly and downwardly. The box then is
typically sealed by applying glue to the inside of the mating
surfaces of the folded flaps prior to them being folded shut, or by
applying tape to the outside of the flaps after they have been
folded shut. If the bottom prior to filling was closed but not
sealed, then typically both the bottom and top are sealed with tape
following filling.
[0004] There exists in the market place a solution for automatic
taping the top and bottom of cases shut after they are filled. One
solution is where the sealer is fed by a conveyor from several
operator filling stations. Another solution is where the filling
station is incorporated into the sealer and as such there is one
operator per sealer.
[0005] There also exists in the market place solutions for sealing
cases with a hot melt adhesive. Most of these apply the hot melt on
the bottom of the case when it is being automatically erected and
prior to filling contents, and then on the top of the case after it
has been filled. These solutions require two machines (the
automatic erector and the top sealer) which are neither compact nor
low cost.
[0006] There is a need for a compact solution for sealing filled
cases with a hot melt adhesive similar to what is currently being
accomplished through the use of tape. The current invention
addresses this need.
SUMMARY OF THE INVENTION
[0007] The invention provides the art with a compact top and bottom
hot melt case sealer with integral hot melt applicator which can
meet the needs of single operator or multiple operator feeds. In
the practice of the invention, the major flaps on the bottom of a
filled case are reopened in order to apply hot melt adhesive, and
then sealed.
[0008] One embodiment of the invention is directed to a hot melt
case sealer wherein previously closed but unsealed major bottom
flaps of a filled case are re-opened in order to apply a hot melt
adhesive to the inside surface of each major flap and re-closed,
after which the bottom of the box becomes adhesively sealed shut.
In another embodiment, the hot melt case sealer wherein previously
closed but unsealed major bottom flaps of a filled case are
re-opened in order to apply a hot melt adhesive to the outer
surface of each minor flap and re-closed, after which the bottom of
the box becomes adhesively sealed shut.
[0009] Another embodiment of the invention is directed to a hot
melt case sealer wherein previously closed but unsealed major
bottom flaps of a filled case are re-opened in order to apply a hot
melt adhesive to the inside surface of each major flap and
re-closed, after which both the bottom and top of the box become
adhesively sealed shut. In another embodiment, the hot melt case
sealer wherein previously closed but unsealed major bottom flaps of
a filled case are re-opened in order to apply a hot melt adhesive
to the outer surface of each minor flap and re-closed, after which
both the bottom and the top of the box becomes adhesively sealed
shut. In a further embodiment, the hot melt case sealer wherein
previously closed but unsealed major bottom flaps of a filled case
are re-opened in order to apply a hot melt adhesive to the outer
surface of each minor flap and/or inner surface of each major flap
and re-closed, after which both the bottom and the top of the box
becomes adhesively sealed shut.
[0010] The case sealer comprises a frame with a conveyor for moving
filled boxes into an area comprising a pair of spaced-apart lateral
drive belts and hot melt nozzles. The drive belt moves the box
through a region in which a hot melt dispensing system
substantially simultaneously applies hot melt adhesive to both the
top and bottom flaps to seal both the bottom and top flaps shut. In
one embodiment the adhesive is substantially simultaneously applied
to the top of the case on the outside surface of the minor flaps
and to the bottom of the case on the outer surface of the minor
flaps. In another embodiment the adhesive is substantially
simultaneously applied to the top of the case on the inner surface
of the major flaps and to the bottom of the case on the inside
surface of the major flaps. In a further embodiment the adhesive is
substantially simultaneously applied to the top of the case on the
outside surface of the minor flaps and to the bottom of the case on
the inside surface of the major flaps. Yet in a further embodiment
the adhesive is substantially simultaneously applied to the top of
the case on the inner surface of the major flaps and to the bottom
of the case on the outside surface of the minor flaps.
[0011] Yet in a further embodiment, an integral part of the case
sealer is a hot melt dispensing system. The integrated hot melt
dispensing system comprises hot melt adhesive, a melt tank having
an interior cavity adapted to receive the adhesive and, optionally,
an automatic feed device integrally connected to the melt tank. In
one embodiment, the system comprises heating elements that are
controlled or programmed to reach a maximum operating temperature
of 250.degree. F.
[0012] In one embodiment, integrated hot melt dispensing system
comprises an automatic dispensing unit for maintaining a supply of
hot melt adhesive in its solid form, a supply connector which
supplies the solid adhesive from the automatic dispending unit to
the interior cavity of the melt tank, a melt tank which comprises
heating elements, a transfer hose connected from the melt tank to
the nozzle, at least one nozzle mounting port including a
dispensing orifice which is opened and closed by a valve, and at
least one nozzle for dispensing molten hot melt adhesive from the
dispensing orifice.
[0013] In one embodiment, the case sealer is a random case sealer,
wherein the apparatus adjusts automatically to accommodate the size
of the box, in particular, the spaced apart laterally positioned
pair of drive belts adjust to suit the size of the box and the hot
melt dispensing equipment's placement of adhesive onto the
flaps.
[0014] Another embodiment of the invention is directed to a
packaging method using the case sealer of the invention. The method
of the invention comprises constructing the box, closing but not
sealing shut the bottom of the box, filling the box with material
to be packaged, moving the filled boxes into an area of a box
sealer comprising a pair of spaced-apart lateral drive belts and
hot melt nozzles. Moving the box via the drive belt through a
region in which a hot melt dispensing system applies adhesive to
the bottom and top flaps, and then closing the flaps whereby the
bottom and top ends of the box become sealed. In the practice of
the invention, hot melt is substantially simultaneously applied to
the top and bottom flaps. In one embodiment the adhesive is
substantially simultaneously applied to the top of the case on the
outside surface of the minor flaps and to the bottom of the case on
the outer surface of the minor flaps. In another embodiment the
adhesive is substantially simultaneously applied to the top of the
case on the inner surface of the major flaps and to the bottom of
the case on the inside surface of the major flaps. In a further
embodiment the adhesive is substantially simultaneously applied to
the top and/or the bottom of the case on the outside surface of the
minor flaps and to the top and/or the bottom of the case on the
inside surface of the major flaps. Yet in a further embodiment, the
adhesive may be applied independently on the inner surface of the
major flap and the outer surface of the minor flap for the top and
the bottom of the case.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0015] FIG. 1 is a side view of one embodiment of the case sealer
of the invention.
[0016] FIG. 2 is on overhead view of the bottom half of the,case
sealer shown in FIG. 1
[0017] FIG. 3 shows a filled box as it receives hot melt adhesive
as it is moved through the adhesive application section of the case
sealer.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The invention provides the art with an alternative method of
sealing a box wherein both the top and bottom flaps of a filled box
are sealed shut with a hot melt adhesive. In accordance with the
practice of the invention, the box is erected, filled, and then
both the bottom and top is sealed shut using a hot melt
adhesive.
[0019] The case sealer of the invention comprises a frame having a
longitudinal axis that includes an entrance conveyor for moving
boxes entering the case sealer along the axis, a pair of
longitudinal spaced-apart, lateral belt drives is located to
receive boxes from the entrance conveyor and to move them into and
out of a hot melt dispensing region and onto a sealing
platform.
[0020] A box or case is first erected in such a manner that the
bottom flaps are closed but not sealed and the top flaps remain
open. The box is filled, and then sealed using the case or box
sealer of the invention. The case sealer of the invention may be
semi-automatic, in that the inner flaps of the top of the box are
manually folded closed prior to being conveyed into the case
sealer. Alternatively, the case sealer may be automatic, wherein
the case sealer comprises a "flap kicker" that folds the inner top
flaps into the closed position as it is being conveyed into the
region where adhesive is applied to the flaps.
[0021] The case sealer of the invention comprises three distinct
regions: entrance conveyor, adhesive application region and sealing
platform.
Entrance Conveyor
[0022] The entrance conveyor comprises a plurality of
interdigitating rollers positioned at a downward angle. The
downward angle will generally range from about 5 degrees to about
10 degrees from horizontal level, typically about 6 degrees. The
entrance conveyor allows the major outer bottom flaps to partially
drop open while the inner flaps remain in a substantially closed
position, thereby retaining the contents within the confines of the
box.
Adhesive Application Region
[0023] The box then enters the adhesive application region
comprising a floor that is open in the center, the center being
flanked by a pair of peripherally located angled floor regions and
a pair of laterally positioned drive belts that pushes or otherwise
moves the box through the hot melt application region. The areas of
angled floor (also referred to herein as the bottom major flap
guide bars) allow the major flaps of the folded box to drop further
in order to receive hot melt adhesive. The angle from each bottom
major flap guide bar to horizontal will generally range from about
1 degrees to about 45 degrees, typically about 5-20 degrees, more
typically about 10-15 degrees. As the box enters the adhesive
application region, and the bottom major flaps fall further,
additional support to retain the inner minor flaps in the closed
position is provided by a plow.
[0024] The plow, which may comprise a pair of applicator nozzles,
is adapted and positioned to provide temporary support to the minor
bottom flaps and/or contents of the box once the major flaps drop
to receive adhesive. A plurality of hot melt dispensing nozzles,
located both above and below the adhesive application region, is
present to apply adhesive to bottom and top flaps as the box is
moved through the adhesive application region. During transport of
the box through the adhesive application region, a pair of nozzles
applies hot melt adhesive to the outside surface of each of the
closed minor flaps of the top of the box while a second pair of
nozzles applies hot melt adhesive to the outside surface of the
closed minor flaps of the bottom of the box. The pair of nozzles
can be positioned to apply the hot melt adhesive to the inner
surface of each of the open major flaps of the top of the box and
the bottom of the box. The nozzles can also be positioned to apply
the hot melt adhesive to the outside surface of each of the closed
minor flaps of the top of the box while the second pair of nozzles
applies hot melt adhesive to the inner surface of the open major
flaps of the bottom of the box. The nozzles can further be
positioned to apply the hot melt adhesive to the inner surface of
each of the open major flaps of the top of the box while the second
pair of nozzles applies hot melt adhesive to the outer surface of
the closed minor flaps of the bottom of the box. The pair of
nozzles can also be independently positioned so that each nozzle
dispenses the hot melt adhesive to either the inner surface of the
open major flaps or the outer surface of the closed minor
flaps.
Sealing Platform
[0025] Following application of adhesive, the box is conveyed to a
region comprising a plurality of flat rollers. As the box leaves
the adhesive application region the bottom flaps are closed as the
box is moved onto the rollers, and the top flaps are closed and,
preferably, compressed to seal both the top and bottom of the
box.
[0026] The case sealer of the invention includes an integrated
system for processing and dispensing a hot melt adhesive. The
system is particularly useful when adapted to process and dispense
adhesives formulated for application at low temperatures, i.e.,
temperatures of 290.degree. F. or less, more typically temperatures
of 160.degree. F. to 260.degree. F., even more typically
170.degree. F. to 200.degree. F. While the invention is not to be
limited to the use of low application temperature hot melt
adhesives, such adhesives can be transported, processed and
dispensed for use in a safer, more economical way.
[0027] The integrated hot melt adhesive dispensing system is
positioned and adapted to dispense hot melt adhesive to the end
flaps of the boxes. Use of a low temperature hot melt means that
the end user would not suffer from problems traditionally
associated with the use of conventional (high temperature
application) hot melt and non integral hot melt applicators. Such
problems include, e.g., hot melt charring which blocks applicator
nozzles and causes downtime, hot melt charring which requires tank
flushing, high temperature hot melt which can cause safety issues,
high temperature hot melt which can cause accelerated wear on the
applicator, and multipurpose applicators which are not designed
specifically for this application and which therefore are too
complex to operate and maintain.
[0028] The integrated hot melt adhesive dispensing system comprises
a hot melt adhesive product, a melt tank preferably with an
integrated level control and, optionally, a high efficiency
automatic dispensing unit.
[0029] The adhesive product used in the system of the invention is
not particularly limited. Virtually any low application temperature
hot melt adhesive may be used in the practice of the invention.
Base polymers suitable for use in formulating low application hot
melt adhesives include amorphous polyolefins, ethylene-containing
polymers and rubbery block copolymers, as well as blends thereof.
Hot melt adhesive compositions based on ethylene/vinyl acetate
copolymer, isotactic or atactic polypropylene, styrene-butadiene,
styrene-isoprene, or styrene-ethylene-butylene A-B-A or A-B-A-B
block copolymers or mixtures thereof may be used. Blends of any of
the above base materials, such as blends of ethylene n-butyl
acrylate and ethylene vinyl acetate and ethylene vinyl acetate and
atactic polypropylene may also be used to prepare hot melt adhesive
compositions. In all cases, the adhesives may be formulated with
tackifying resins, oils plasticizers, waxes and/or other
conventional additives including stabilizers, anti-oxidants,
pigments and the like.
[0030] When the adhesive dispensing system is in operation, the hot
melt adhesive, in solid form, is continuously fed, conveyed or
dispensed from a solid material staging area or depot, also
referred to herein as an automatic dispensing unit or automatic
feed tank, drum or bin, via a supply passage or conduit such as a
tube, hose or the like, to the melt tank.
[0031] In one embodiment, conveyance into the melt tank is
controlled by an automatic feed tank or automatic dispensing unit
that is integrally connected to the melt tank. The automatic
dispensing unit automatically fills the melt tank in response to a
level detector present in the melt tank.
[0032] In the melt tank, heating elements heat the adhesive
contained therein to a predetermined set temperature. Use of a low
application temperature hot melt adhesive and temperature controls
of the invention enable the positioning of the dispensing unit
closer to the melt tank.
[0033] In one embodiment, an integrated control panel is used to
control the adhesive level and to control the temperature. When
using a low application hot melt adhesive, the control will be set
to prevent temperatures higher than 290.degree. F. In one
embodiment, the control will be set to prevent the temperature for
going above about 250.degree. F. In another embodiment, the control
will be set to prevent the temperature for going above about
200.degree. F.
[0034] An audible alarm will preferable be present to indicate when
the solid hot melt dispensing unit is empty, when the melt tank is
empty and when the temperature is outside of the desired or
predetermined limit.
[0035] The system will also comprise a hot melt dispensing port, a
pump, and a transport hose for transporting molten adhesive to the
application nozzles. When using a low application temperature hot
melt adhesive, the molten hot melt can be transported up to 10 m,
more typically up to 4 m, from the melt tank to the application
nozzles.
[0036] In one embodiment, the system comprises a hot melt adhesive,
an automatic dispensing unit, a supply connector and a melt tank,
where the solid hot melt adhesive is automatically fed by way of an
automatic dispensing unit (automatic feed) into a heated melt tank,
where the adhesive melts and is maintained at a predetermined
temperature. Melted adhesive is maintained at a predetermined level
by level detectors present in the melt tank. Molten adhesive is
then pumped from the melt tank through a mounting port, bore or
outlet which includes a dispensing orifice which is opened and
closed by a valve stem, through transfer hose to a nozzle for
dispensing molten hot melt adhesive onto the surface of a box.
[0037] The shapes of the unit and/or parts making up the automatic
dispensing unit and melt tank are not particularly limiting. The
automatic dispensing unit and/or melt tank may comprise a single
wall (e.g., is cylindrical in shape), or a plurality of walls
(e.g., is square, rectangular, or the like).
[0038] The automatic dispensing unit is integrally linked to the
melt tank and these system components may be manufactured of the
same or different material. Solid adhesive, in the form of pellets
or other such conventional form, is introduced into the dispensing
unit via an adhesive inlet valve, e.g., by blowing or other
conventional means. Means for removing air accompanying the
introduction of the solid adhesive into the automatic dispensing
unit may be used. If desired, baffles or other such means may be
present in the automatic dispensing unit which function to direct
solid adhesive toward the melt tank and/or deflect heat.
[0039] The melt tank comprises heating means, and may include a
grid heated via either cartridge or band heater. A plurality of
heat elements may be employed throughout the tank to optimize melt
down and molten feed rates. The heaters may be positioned in such a
way to provide heat to both the adhesive in the hot melt tank as
well as the pump mechanism. Alternatively separate sets of heating
elements may be used to provide heat to the adhesive in the hot
melt tank and to adhesive in the pump mechanism. Heating elements
will be thermostatically controlled and will comprise circuitry for
providing electrical power.
[0040] The melt tank is connected to a dispensing unit through a
one way check valve which allows material into the molten chamber
of the pump (on the piston's return stroke) while restricting
reverse flow when under pressure from the pump (e.g., due to
forward pumping stroke of piston). Dispensing may also be
accomplished via a gear pump, for example.
[0041] The invention provides a case sealer that comprises a closed
system for automatically processing and dispensing hot melt
adhesive at multiple sites, wherein the adhesive level in the melt
tank will be maintained at a predetermined level adhesive level
using an automatic feed device and level sensor. The closed system
prevents contamination and helps to keep work areas safe and clean.
Moreover, when using a low application temperature adhesive the
life of consumable parts such as nozzles, filters and modules is
prolonged and wear observed in hoses, pneumatic assembly, vibrator,
feeder pneumatic assembly as well as control card, power card,
thermostat, RTD, level sensor control board decreases.
[0042] One embodiment of the invention is directed to a hot melt
case sealer wherein previously closed but unsealed major bottom
flaps of a filled case are re-opened in order to apply a hot melt
adhesive to the inside surface of each major flap and re-closed,
after which the bottom of the box becomes adhesively sealed shut.
Another embodiment of the invention is directed to a hot melt case
sealer wherein previously closed but unsealed major bottom flaps of
a filled case are re-opened in order to apply a hot melt adhesive
to the outside surface of each minor flap and re-closed, after
which the bottom of the box becomes adhesively sealed shut. In a
further embodiment, a hot melt case sealer wherein previously
closed but unsealed major bottom flaps of a filled case are
re-opened in order to apply a hot melt adhesive substantially
simultaneously to the top and bottom flap to the outside surface of
each inner flap and re-closed, after which the bottom of the box
becomes adhesively sealed shut. Yet in a further embodiment, a hot
melt case sealer wherein previously closed but unsealed major
bottom flaps of a filled case are re-opened in order to apply a hot
melt adhesive substantially simultaneously to the top and bottom
flap to the inside a surface of each major flap and/or the outside
a surface of each minor flap and re-closed, after which the bottom
of the box becomes adhesively sealed shut.
[0043] The nozzles may be positioned to allow the hot melt adhesive
to be applied at either the minor and/or the minor flaps for both
the top and the bottom of the box. Moreover, the nozzles may be
independently positioned to dispense hot melt adhesive on different
or the same flaps of the top and the bottom of the box.
[0044] Various patterns and amounts of the hot melt adhesive may be
dispensed from the nozzle. The patterns may be controlled by
dispensing the hot melt adhesive in a desired pattern by moving the
nozzles and/or moving the box in the adhesive application region on
the conveyor belt. The amount of hot melt adhesive dispensed is
controlled by the length of time the nozzles dispense the adhesive
in each position and/or by varying the pump pressure. The specific
pattern design and the amount of adhesive emitted can be
mechanically and/or electronically controlled.
[0045] The invention will hereinafter be described by reference to
the accompanying drawing Figures.
[0046] FIG. 1 represents a side view of one embodiment of a case
sealer of the invention. FIG. 2 is an overhead view of a case
sealer, particularly the bottom portion of the case sealer, of the
invention. FIG. 3 shows a filled box as it receives hot melt
adhesive as it is moved through the adhesive application
region.
[0047] Referring to FIG. 1, the case sealer comprises a frame
having a longitudinal axis that includes an entrance conveyor (1),
an adhesive application region (2) and a sealing platform (3). The
case sealer may be stationary or may be supported on casters (4) to
allow the case sealer to be easily moved to desired location.
[0048] The entrance conveyor (1) moves boxes along the longitudinal
axis and into the adhesive application region (2). The entrance
conveyer (1) comprises a series of interdigitating rollers shown in
more detail in FIGS. 2 (5 and 6). A center rail and a pair of
longitudinal spaced-apart, lateral belt drives (7) is located to
receive boxes from the entrance conveyor (1) and move them into and
out of a hot melt dispensing region (2). The case sealer comprises
a "flap kicker" (20a) that folds the inner minor top flaps into the
closed position (20b) as it is being conveyed into the region where
the hot melt adhesive is applied to either or both the minor or
major flaps. The hot melt adhesive is emitted from the nozzles (16)
attached to top minor flap guard (19). One top nozzle (16) is
shown. After the adhesive has been applied, the box is moved to the
sealing platform (3). A compressor (11) is used to shut and seal
the box.
[0049] Referring to FIGS. 1 and 2, an integral part of the case
sealer is a hot melt dispensing system. The integrated hot melt
dispensing system comprises an automatic dispensing unit (24) for
maintaining a supply of hot melt adhesive in its solid form, a
supply connector (25) which supplies the solid adhesive from the
automatic dispensing unit to a melt tank (22), where the solid
adhesive is melted into a molten state. A transfer hose (21)
transfers the molten hot melt adhesive from the melt tank to the
application nozzles (14, 15, and 16) where the adhesive is
dispensed onto a box.
[0050] Referring to FIGS. 2 and 3, the adhesive dispensing region
(2) comprises a floor that is open in the center (8), the center
being flanked by a pair of peripherally located angled floor
regions, also referred to as the bottom major flap guide bars (9).
The bottom nozzles (14, 15) dispense hot melt adhesive onto the
bottom flaps of the box. Following application of adhesive, the box
(10) moves to the sealing platform (3) where the exterior side of
the bottom minor flaps contact adhesive applied to the interior
portion of the bottom major flaps and the top flaps are folded and
compressed using a compressor (11) whereby the box is sealed shut.
The sealing platform (3) receives the box and this may be made of a
movable belt or a static platform.
[0051] FIG. 3 shows the box as it receives hot melt adhesive as the
box moves through the adhesive application section of the case
sealer. Referring to FIG. 3, the areas of angled floor (major flap
guide bars) (9) allows the major flaps (12) of the folded box (10)
to drop in order to receive hot melt adhesive (13) on the other
minor flap. A plurality of hot melt dispensing nozzles (14, 15, 16,
17), located both above and below the box in the adhesive
application region are present to apply adhesive to the flaps of
the case as it moves through the adhesive application region.
During transport of the box through the adhesive application
region, a pair of top nozzles (16, 17), attached to the top minor
flap guard (19), apply hot melt adhesive to the each of the closed
minor flaps (18I), open major flaps (18J), one closed minor flap
and one open major flap or to both closed minor flaps and open
major flaps of the top of the box. Also a second pair of nozzles,
bottom nozzles (14, 15) attached to the center rail (26), apply hot
melt adhesive to the inside surface of each of the closed minor
flaps (12I), open major flaps (12J), one closed minor flap and one
open major flap or to both closed minor flaps and open major flaps
of the bottom of the box (12). In one embodiment, a center rail
(26) comprising a pair of nozzles, is adapted and positioned to
provide temporary support to the minor bottom flaps and/or contents
of the box once the major flaps drop to receive adhesive. A flap
kicker may be present which will be spaced above and the lateral
conveyors. The flap kicker is adapted to engage and hold box flaps
shut and is adapted to mount an adhesive nozzle centrally thereon
for sealing the box flaps shut.
[0052] Many modifications and variations of this invention can be
made without departing from its spirit and scope, as will be
apparent to those skilled in the art. The specific embodiments
described herein are offered by way of example only, and the
invention is to be limited only by the terms of the appended
claims, along with the full scope of equivalents to which such
claims are entitled.
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