Note: Descriptions are shown in the official language in which they were submitted.
CA 02317715 2002-05-15
WO 99IS0054 PGTNS98l220a2
Title
10
'15
A FORMING APPARATt3S FOR AN ELEVATED BOTTOM CARTON
Technical Field
The present invention relates to a bottom forming apparatuses for cartons:
Specifically; the present invention relates to a bottom forming apparatus for
a
carton having portions of the bottom elevated to protect the raw paperboard
edges
from damage and absorption of moisture.
Background Art
Cartons fabricated from a carton blank on a form, fill and seal packaging
machine risk absorption of moisture into the raw paperboard edges of the
bottom
of the carton. This absorption is accelerated if the raw paperboard edges are
20 damaged and the carton is continuously exposed to moisture. The
transportation,
loading and' storage of the carton from the conveyance between the packaging
machinelpacker unit and the retailer display are all sources for damage and
moisture absorption.
The raw paper edges are a by-product of the composition of the carton
25 blank. Generally, the carton blank is cut and scored from a sheet of coated
fiberboard material. The coated fiberboard material is usually composed of
three
layers, and may have a 'barrier layer juxtaposed between fiberboard layers.
The
exposed surfaces of this sheet are coated with a polymer material such as
polyethylene: However, the coating does not extend to the edges which are thus
30 left uncoated; and partially unprotected at least to moisture and sensitive
to
CA 02317715 2002-05-15
y_ r
WO 99150054 PCTIUS98l22002
2
damage. When the carton is erected and partially formed, these rawpaper edges
are most prevalent at the bottom of the carton. If moisture is absorbed into
the
raw paper edges, the water may be absorbed throughout the fiberboard interior
layer, which due to its cellulose-like nature; has a strong affinity for
liquids.
This absorption of moisture may compromise the integrity of the carton thereby
rendering it defective.
This problem has yet to be directly addressed by the packaging industry.
However, inventions directed to resolving the stability of cartons have been
disclosed in the prior art. Mills et al; U.S. Patent Nos. 5;482,204, and
5,588,943,
respectively for a Carton Bottom Sealer and Carton Bottom Sealing Dies
disclose
cartons having an embossed inverse pyramidal bottom which is directed to
providing greater stability to the filled carton and to reduce bulging of the
carton.
It should be noted, as shown in FIGS., 8 and 9 of the Mills et al Patents,
that the
end portions of the exposed raw paper edges of the bottom of the carton are
not
embossed, and therefore are susceptible to moisture absorption.
Fujikawa et al, U.S. Patent No. 5,222,667, for a Container Made Of Paper-
Base Laminate, similarly discloses a carton having an inverted V-shaped bottom
to provide greater stability to the carton. As shown in FIG. 6 of the Fujikawa
et
al Patent, the raw paper edge of panel 27 is not inverted and is susceptible
to
moisture absorption since the V-shaped inversion begins at the raw paper edge
and
since the inversion must be centered to provide stability to the carton.
CA 02317715 2002-05-15
Disclosure of the Invention
The present invention resolves the problem of absorption of moisture through
raw
paperboard edges by providing a carton having the raw paper edges elevated in
order to
protect the raw paperboard edges and reduce the susceptibility of moisture
absorption.
The present invention is able to accomplish this without adversely affecting
the carton.
One aspect of the present invention is a bottom forming apparatus having a
sealing plate and a mandrel cap formed to elevate the raw paperboard edges of
the carton.
The mandrel cap has a recess with an angled edge corresponding to the
placement of the
1o raw paperboard edge of the bottom of a carton. The angled edge may have the
angle
downward to form a beveled edge. The sealing plate has a first elevated
portion
partitioned into two sections, a traversal section and an edge section which
mate with the
recess area and angled edge of the mandrel cap to form the elevated portions.
The
sealing plate may also have a second elevated portion thereon.
15 Various embodiments of the sealing plate are set forth for elevating the
bottom of
cartons having different bottom configurations.
Another aspect of the present invention is a method for forming a carton
having
an elevated bottom.
More specifically, the present invention provides an apparatus for forming
2o elevated portions on a carton bottom; the apparatus comprising a mandrel
cap having a
body with an engagement surface, a first end and a second end opposite the
first end, the
engagement surface having a first recess traversing the engagement surface
from the first
end to the second end, the engagement surface having an angled edge extending
along a
portion of the first end, and a sealing plate for engaging with the mandrel
cap, the sealing
25 plate having a pressing surface, a f rst end and a second end opposite the
first end, the
pressing surface having a first elevated portion having a traversal section
and an edge
section continuous and substantially coplanar with one another, the traversal
section
extending substantially from the first end to the second end, and the edge
section
extending substantially perpendicular to the traversal section along a portion
of the first
30 end; wherein the first elevated portion and the pressing surface are on
separate parallel
planes.
The present invention also provides a method of forming a carton having
elevated
portions on the bottom of the carton, the method comprising placing an erected
carton
CA 02317715 2002-05-15
3a
blank on a mandrel, the mandrel having a mandrel cap having a body with an
engagement surface, a first end and a second end opposite the first end, the
engagement
surface having a first recess traversing the engagement surface from the first
end to the
second end, the engagement surface having an angled edge extending along a
portion of
the first end, rotating the mandrel with the erected carton thereon to a
bottom sealing
station, pressing a sealing plate against the bottom panels of the carton and
thus the
mandrel cap, the sealing plate comprising a pressing surface, a first end and
a second end
opposite the first end, the pressing surface having a first elevated portion
having a
traversal section and an edge section continuous and substantially coplanar
with one
to another, the traversal section extending substantially from the first end
to the second end,
and the edge section extending substantially perpendicular to the traversal
section along a
portion of the first end, wherein the first elevated portion and the pressing
surface are on
separate parallel planes, and releasing the carton with an elevated bottom
from the
mandrel.
is The present invention also provides a packaging machine for fabricating a
series
of cartons, each carton having an elevated bottom; the packaging machine
comprising a
bottom forming station comprising, a mandrel cap having a body with an
engagement
surface, a first end and a second end opposite the first end, the engagement
surface
having a first recess traversing the engagement surface from the first end to
the second
2o end, the engagement surface having an angled edge extending along a portion
of the first
end, and a sealing plate for engaging with the mandrel cap, the sealing plate
having a
pressing surface, a first end and a second end opposite the first end, the
pressing surface
having a first elevated portion having a traversal section and an edge section
continuous
and substantially coplanar with one another, the traversal section extending
substantially
2s from the first end to the second end, and the edge section extending
substantially
perpendicular to the traversal section along a portion of the first end,
wherein the first
elevated portion and the pressing surface are on separate parallel planes, a
conveyor for
transporting the cartons from the bottom forming station, and a filling
station for filling
the cartons with a desired product.
CA 02317715 2002-05-15
m r
WO 99150054 PCT/US98I22002
4
Brief Description of the Drawings
Several features of the present invention are further described in
connection with the accompanying drawings in which:
FIG. 1 is a schematic view of a packaging machine for producing cartons
having an elevated bottom.
FIG. 2 is an isolated schematic view of a bottom forming assembly of the.
present invention.
FIG. 3 is a bottom pefspective view of one embodiment of a carton
fabricated from bottom forming assembly of the present invention:
FIG. 4 is an isolated top perspective view of a mandrel cap of the present
invention.
FIG. 5 is a top plan view of the mandrel cap of FIG. 4.
FIG. 6 is an isolated top perspective view of a preferred embodiment of a
sealing plate of the present invention: .
FIG. 7 is a side plan view of the sealing plate of FIG. 6.
FIG. 8 is a top plan view of the sealing plate of FIG. 6.
FIG. 9 is a side plan view of a sealing plate and mandrel cap of the present
invention engaging a carton to form an elevated bottom.
FIG. 10 is a top perspective view of an alternative embodiment of a sealing
plate of the present invention.
FIG. 11 is a top perspective view of an alternative embodiment of a
sealing plate of the present invention.
FIG. I2 is a top perspective view of an alternative embodiment of a seating .
plate of the present invention.
CA 02317715 2002-05-15
WO 9915045~t PCT/US98122002
FIG. I 3 is a top plan view of the sealing plate of FIG. 12.
FIG: 14 is a top perspective view of an alternative embodiment of a sealing
plate of the present invention.
FIG. 15 is a top plan view of the sealing plate of FIG.14.
FIG. 16 is a top perspective view of an alternative embodiment of a sealing
plate'of the present invention.
FIG. I 7 is a top plan view of the. sealing plate of FIG: 16.
CA 02317715 2002-05-15
W0 99l50a54 PCTIUS98/22002
6
Best Modes For Carrying Out The Invention
As shown in FIGS. 1 and 2, a packaging machine for forming, filling and
sealing cartons is generally designated 20. One example of such a machine is a
TETRA REX~ packaging machine available Tetra. Pak, Inc. of Chicago, Illinois.
A plurality of carton blanks 22 axe fed from a magazine 21 to a bottom forming
station 2~of the machine 21. During the transfer from the magazine 21 to the
bottom forming station 25, each of the carton blanks 22 is erected to a
partially-
formed state wherein the top and bottom of the carton is open. On the bottom
forming station 25, as best shown in FIG. 2, the bottom of the carton is
formed at
a number stations. First, an erected-carton blank 21 is placed upon a mandrel
26.
The mandrels 26a-f rotate about a turret 27. Although six mandrels are shown,
other configurations have five or four mandrels rotating about a turret 27.
The
bottom panels of each carton are pre-folded at a pre-folding tation 28, and
then
heated at a heating station 29. The bottom panels are then heat sealed
together at a
sealing station 30. The sealing of the bottom panels is accomplished by
pressing a
sealing unit SO against the bottom panels as they lie on a mandrel 26, and
specifically a mandrel cap 40. The carton 100, with its bottom sealed, is then
ejected from the mandrel 26 onto a conveyor 32 for further processing on the
packaging machine 20. The elevated bottom is formed at the sealing station 30
by an unidue sealing plate 50 and an unique mandrel cap 40.
As shown in FIG. 3, the bottom of the carton 100 has an elevated portion
I 20 bounded by substantially planar portions 160 and I 6?.. The planar
portions
160 and I62 are substantially perpendicular to side panels I 12a, 112b and I
12c
and 112d, nat shown. The planar portions 160 and 162 contact the conveyor belt
.
CA 02317715 2002-05-15
_, ,
WO 99/50054 PCT/US98l22002
7
154 while elevated portion 120 is elevated above the belt 154 and any moisture
thereon. The same applies during distribution whether in a crate or a shelf at
a
store.
The elevated portion 120 is further defined by angled portions 164 and 166
and elevated planar portion 170. The elevated planar portion 170 is further
defined as elevated planar portion 170a and elevated planar portion 170b. The
elevated planar portion l7Ua substantially includes a portion of panel 132b
while
elevated planar portion 170b includes a portion of panel 1324. The exposed raw
paper edge 140a extends across the bottom of the carton 100, from the end of
panel 112 a to the end of panel 112c, not shown. Likewise, the elevated
portion
120 extends across the bottom of the carton 100. The elevated portion 120 may
be centered on the bottom of the carton 100 with planar portions 160 and 162
being equal in area to each other. However; those skilled in the pertinent art
will
recognize that planar portions I 60 and I62 may be unequal and elevated
portion
120 may be uncentered without departing from the scope and spirit of the
present
invention.
Elevated portion 170a, angled portion 1G4 and planar portion 160 may all
be part of bottom panel 132b. Also, elevated portion 1?0b, angled portion 166
and planar portion 162 may all be part of bottom panel 132d.
The exposed edge 140b is substantially perpendicular to exposed edge
140a. A side elevated portion I20a elevates this exposed edge 140b thereby
preventing moisture absorption as with exposed edge 140a. The side elevated
portion I 20a has an angled portion 172 which engages planar portion I60, side
panel 112a, and angled portion 164. Those skilled in the art will recognize
that
CA 02317715 2002-05-15
W0 991554 PCTIUS98/220Q2
8
any exposed raw paperboard edges may be elevated in a similar fashion without
departing from the scope and content of the present invention.
Approximately in the center of the elevated portion 120 is a secondary
elevated portion 180. The secondary elevated portion 180 prevents loss of
elevation in the center of the bottom of the carton I UO during transportation
from a
packaging machine to the retailerlwholesaler to the consumer. As is apparent,
the
center of the bottom of the carton 100 is most susceptible to deelevation from
the
weight of the product. The weight of the product in the carton 100 is focused
on
the center of the bottom of the carton 100, and thus it is necessary to
provide
greater elevation in this area: This greater elevation is provided by the
secondary
elevated portion 180 which compensates for gravitational forces exerted by the
product on the center of the bottom of the carton 100.
In a preferred embodiment, the secondary elevated portion 180 is
triangular in shape with its apex 181 near the exact center of the bottom of
the
carton 100. The secondary elevated portion I8U is substantially contained
within
elevated planar portions 170a and 170b. However, there is a transition to
angled
portion l b6. Alternatively, the triangular shaped embodiment of the secondary
elevated portion 180 may be rotated any degree from I-360 degrees; about apex
181 while not departing from the scope and spirit of the present invention.
Thus,
the secondary elevated portion 180 tray iie entirely within elevated planar
portion
170a.
In the preferred embodiment, the secondary elevated portion I 80 is
partially defined by secondary angled portions 182, I 84, 18b and 188. The
secondary angled portions 182 and 184 form a transition from the secondary
elevated portion I80 to elevated planar portion 170a whereas the secondary
CA 02317715 2002-05-15
WO 99150054
9
PCTlUS98122002
angled portions 186 and 188 form a transition from the secondary elevated
portion 180 to elevated planar portion 170b:
A mandrel cap 40 of the present invention is shown in FIGS. 4 and 5. The
mandrel cap 40 has an engagement surface 41 a-b that engages with the bottom
panels for mating with the sealing plate 50 to form he elevated bottom carton
100.
Generally, the mandrel cap 40 has a f rst end 42, a second end opposite the
first
end, and thiYd and fourth ends 44 and 45 as shown. The third and fourth ends
44
and 45 may be non-straight as 'shown or straight. The first end may be
partitioned
into a frst pertion 42a and a second portion 42b. The engagement,surface 41 is
traversed by a recess 46 that extends from the first end 42 to the second end
43.
The width of the recess 46 is generally less than the combined area of
engagement
suxfaces 4I a-b, however those skilled in the pertinent art will recognize
that the
width may be equal or larger than such combined area.
The engagement swface 41 also has an angled edge 47 along the fwst
portion 42a of the first end 42. The angled alge 47 connects with the recess
46 at ,
the transition edge 48b. Another transition edge 48a Iies opposite the first
transition edge 48b: The mandrel cap 40 may also have an elliptical groove 49_
FIGS. 6-8 illustrate a preferred embodiment of the sealing plate 50 of the
20' present invention. The sealing plate has a; pressing surface 51 that lies
on a first
horizontal plane, and which engages with the bottom panels of a carkon 100 and
the mandrel cap 40. The generally flat pressing surface 51 is interrupted by a
first
elevated portion 52 which niay be partitioned into a traversal section. 52a
and an
edge section 52b: The traversal section 52a traverses the pressing surface 51
from
a first end 53 of the sealing plate SO to a second end 54 of the sealing plate
50.
CA 02317715 2002-05-15
WO 99/50054 PCT/t3S98/22002
The sealing plate 50 will also have a third end 5S and a fourth end 56. The
plan-
section of the sealing plate 50 may be square, rectangular, circular,
triangular or
the like. The edge section 52b is generally perpendicular to the traversal
section
52a, and edge section 52a extends along a portion. 53a of the first end 53 of
the
5 sealing plate 50.
The first elevated portion 52, including both sections 52a and S2b, is
generally flat and Iies oma second horizontal plane above that of the first
horizontal plane defined by the pressing surface 51. However, the edge section
52b may lie on a different horizontal plane than the traversal section S2a,
and both
10 sections 52a-b may be non-flat surfaces. The first elevated portion 52 is
interrupted by a second elevated portion b0 that generally lies in the
traversal
section S2a: Although shown as triangular; the second elevated portion 60 may
be of any shape or configuration. 'The second elevated portion 60 is generally
flat
and lies on a third horizontal plane above the second horizontal plane.
A second pressing layer 62 may be disposed on the sealing plate 50. The
second pressing layer 62 may cover a portion of the traversal section 52a of
the
first elevated portion 52. In general, the second pressing layer 62 will lie
above the
second horizontal plane but below the third horizontal plane. A pressing
surface
recess layer 63 is generally flat and lies below the first horizontal plane.
The
recess area 63 is defined by the pressing surface S l b, the edge section 52b;
the
traversal section 52a and the fourth end 55 of the seal plate 50.
In general, the height variations on the sealing plate SO are connected by a
plurality of transition edges 64a-i; the most important of which are
transition
edges 64a and 64b which assist in the elevation of the elevated portions 120
and
120a on the elevated bottom carton 100, as shown in FIG. 3. The transition
edges
CA 02317715 2002-05-15
WO 99150054 . PCTlUS98l22002
91
64a i are preferably beveled for a gradual transition from one plane the next.
However, those skilled in the art will recognize that some or all of the
transition
edges may not be beveled and may have a steeper transition between planes or a
non-flat edge. A plurality of channel block protrusions 65a-1 may be disposed
about the sealing plate 50, on the pressing surface 51, the first elevation
52; the
second pressing layer 62 and at the transition edges 64a-i. The channel block
protrusions 65a-1 act to create a further moisture barner in the carton I00
should
the raw paperboard edges I40a and 140b begin to wick.
FIG: 9 shows a carton 100 having its bottom formed by simultaneous
engagement between the sealing plate 50 and the mandrel cap 40. The mandrel
cap 40 is attached or integrated therewith a mandrel 25. The mandrel 26 may
also
have a plurality of support 73 engaging with the mandrel cap 40. The bottom
panels 132a-d of the carton 100 are sealed together and embossed to form the
elevated portions 120 and I20a. The bottom forming may occur at the bottom
forming station.30 disposed about the mandrels 2b rotating on the turret 27.
Alternatively, the carton 100 may be placed onto an isolated mandrel cap 40
and
sealing plate 50 for bottom forming before conveyance to further stations on
the
packaging machine 20.
FIGS.' 10 and l I are alternative embodiments of the sealing plate: The
sealing plates SOa-b of FIGS. 10 and 11 are slight variations on the sealing
plate
50 of FIG. 6, The sealing plates SOa-b are without many of the various
elevations
of the sealing plate 50 of FIG. 6, most noticeably the second elevated portion
60
on sealing plate SOa:
FIGS. 12 and I3 represent different views of an alternative
embodiment of the sealing plate of the present invention. Similarities between
CA 02317715 2005-O1-18
WO 99/50054 PCTlUS98/22002
12
the sealing plate 50 of FIG. 6 and the sealing plate 50c of FIGS. 12 and I 3
will
utilize the same reference designations. The sealing plate SOc has a sixth
panel
recess 80 disposed on the first elevated portion 52a and a portion of the
second
elevated portion 60. Although the recess 80 lies below the second horizontal
plane of the first elevated portion 52, the recess 80 may have a surface above
the
first horizontal plane of the pressing surface 51. The intersection 81 of the
recess
80 and the second elevated portion 60 may have a surface that lies on the
second
horizontal plane of the first elevated portion 52. The sealing plate SOc is
primarily directed at providing an elevated bottom on a TETRA REX~ sixth
panel skived edge carton.
FIGS. 14 and 15 represent different views of an alternative embodiment of
the sealing plate of the present invention. Similarities between the sealing
plate
50 of FIG. 6 and the sealing plate SOd of FIGS. 14 and 15 will utilize the
same
reference designations. The sealing plate SOd is primarily directed at
providing an
elevated bottom on a carton formed from a low resource carton blank such as
the
one described in co-pending U.S. Patent 5,860,588, filed on
December 13, 1996, entitled Stackable Gable Top Carton And Corresponding Top
Interlocking Carton Blank. The sealing plate SOd has the pt~essing surface 51
a-b and first elevated
portions 52a-b, although the edge portion 51 b is not adja~:ent the traversal
portion
52a. The sealing plate SOd also has a plurality of second elevated portions
60,
60a, 60 b and 60c which may all lie on the third horizontal plane. A plurality
of
channel protrusions 65 are also dispersed throughout the sealing plate SOd.
The
various elevations also have transition edges between different elevations.
CA 02317715 2002-05-15
WO 99150054 PCT/US98122003
FIGS. 26 and 17 repzesent different views of an alternative embodiment of
the aealing plate of the present invention. Similarities between the sealing
plate
50 of FIG. 6 and the sealing plate SOe of FIGS. 16 and 17 will utilize the
same
reference designations: The sealing plate SOe is primarily directed at
providing an
elevated bottom on a carton formed from a PURE-PAK~ carton blank. The
sealing plate SOe has the pressing surface S l a-b and first elevated portions
52a-b.
'The sealing plate SOe also has a plurality of second elevated portions 60 and
60d
which may both lie on the third horizontal plane. A plurality of channel
protrusions 65 are also dispersed throughout the sealing plate SOe. The
various
elevations also have transition edges between different elevations. The second
pressing surface 62 extends along the traversal portion 51 a and is
interrupted by
the second elevated portion 60.
