Note: Descriptions are shown in the official language in which they were submitted.
CA 02244779 1998-09-14
This is a division for co-pending Canadian Patent
Application No. 2,074921 flled 3 July 1992.
Backqround of the Invention
The inventlon disclosed hereln pertains to applying
and sealing labels to containers and to the containers
resulting from treatment with the method.
A machine for applylng and sealing labels to
containers is described in U.S. Patent 4,694,633. In thls
machine, each container is supported on a rotating disk so
that the container rotates, as it ls carried by a turntable,
to serve as a mandrel about which the label is wrapped. At
the start of container rotation, a vacuum bar is driven into
~uxtaposition with the container periphery. The vacuum bar
attracts the leading end of a label and carries the label
around the contalner sufflciently for the tralllng end of the
label to overlap the leadlng end. At this time, the
overlapped ends are subjected to a heating element or a ~et of
hot air which seals the trailing end to the leading end of the
label. The vacuum bar is then withdrawn. This leaves a free
space between the label and the container so the label flts
loosely on the container. Thus, the additional step of heat
shrinking the entlre label onto the contalner is re~uired.
60895-1469D
CA 02244779 1998-09-14
The machine is only suitable for applying labels which
are heat-shrinkable. Heating the entire surface of
the label on the container is expensive and can result
in wrinkles developing in the label. The machine is
also not suitable for labeling prefilled aerosol cans
which cannot be heated safely. Moreover, the thin
suction bar and associated control mechanism are cost-
ly to manufacture and are vulnerable to damage.
Another machine for wrapping labels around
rotating containers is disclosed in U.S. Patent
4,272,311. In this machine, containers are conveyed
in a straight line past an application station where
a web of labels is drawn from a supply roll. Adhesive
is applied at the interface of the leading edge of the
label and the container. The leading edge of the web
is then pressed against the container by means of a
revolving belt. The individual label is cut from the
web only after the web is partially wrapped around the
container. To provide time for cutting, the web is
stopped with a clamping device and the label which is
already in contact with the container is torn or cut
from the web along a perforated web. The label is
then continuously rotated by reason of being in con-
tact with the belt until the label is completely
wrapped around the container. The overlap region of
the leading and trailing ends of the label can be
joined by having previously applied adhesive to the
trailing end of the label or the trailing end can be
sealed to the leading end by applying heat to the
overlapped region. One disadvantage of the machine is
that the adhesive-coated label is not separated from
the web until the label is partially wrapped around
the container which requires that the web be stopped
for severing the label. This is obviously disadvanta-
geous in that the method is intermittent rather than
-
CA 02244779 1998-09-14
continuous which results in its product output being
low. When the machine is driven at higher speeds,
there is not sufficient time allowed for a reliable
fusion of the leading and trailing edges of the label
to achieve a good seal. Consequently, applying adhe-
sive to a large area on the inside of the label or to
the outside of the container is often necessary. This
is highly disadvantageous, particularly in the appli-
cation of labels composed of thin and transparent
film, for reasons of appearance. The known apparatus
is not suitable for achieving high production rates of
40,000 to 80,000 bottles or cans per hour as is a com-
mon requirement in the beverage industry today.
U.S. Patent 4,416,714 discloses applying an
adhesive coated leading end of a label to a rotating
container to effect wrapping of the label on the con-
tainer. The label is secured by adhering the trailing
end over the underlying leading end. Labels are fed,
one at a time, to the containers from a vacuum drum.
Heat shrinking of the edges of the label to the con-
tour of the container is disclosed, but heat sealing
the overlapped label ends in addition to having adhe-
sive applied near the trailing end as is described
herein is not disclosed.
Japanese Patent No. Sho 57-23620, published
May 19, 1982, discloses wrapping a heat shrinkable
label around a container and heat sealing the overlap-
ping trailing and leading ends of the label. The top
and bottom edges of the label are heat-shrunk to con-
form them to the contour of the container. A back-up
bar is placed behind the overlapping ends, at least
along the edges which extend over the contour, to al-
low pressing the overlapping ends together by a hot
heat seal member or a cold member when the label ends
are sealed with glue. There is no disclosure of how
CA 02244779 1998-09-14
the heat sealing tlme can be held substantially constant for
dlfferent contalner transport speeds as ls descrlbed hereln.
Summary of the Invention
The present invention provldes a contalner havlng a
cyllndrical section on which a sealable label ls wrapped so
that an overlap region ls formed between the leading edge and
traillng edge of the label and the trailing edge ls sealed to
the leadlng edge of the label, characterlzed ln that the label
ls attached to the cyllndrlcal sectlon of the contalner by at
least one narrow adheslve reglon near the leadlng edge of the
label and lf necessary near the tralllng edge of the label,
while the remaining area ls kept free of adhesive.
Only a small amount of adheslve ls re~ulred, applled
elther to the leadlng edge of the label or to the container,
to attach the leading edge of the label to the container
rotating lt to cause wrapplng of the label around the
contalner. Only sufficient adheslve is used on the leading
edge to ensure that the label does not slip from the container
during wrapping. The label is actually secured about the
container when the tralling end of the label overlaps the
leading end and the overlap region is heat sealed. The result
is an extremely fast labeling method which produces containers
on which the label is smooth and attractive even though a very
thin or transparent film-type label is used. The width or
height, as opposed to the length, of the label can be
dimensloned so that the upper and
60895-1469D
CA 02244779 1998-09-14
-- 5
lower longit--~;n~lly extending edges of the label ex-
tend over radially inwardly tapered top and bottom
margins of the container such that only the longitudi-
nal edges, rather than the whole label, need to be
heat shrunk to cause the edges to conform to the con-
tour of the container. The adhesive selected to at-
tach the leading edge of the label to the container is
preferably one whose adhesive strength diminishes with
time following sealing. This is permissible since the
label is tightly conformed to the container surface by
the tight wrapping and by shrinking the upper and/or
the lower longitudinally extending edges. When suit-
able label material is used on containers composed of
plastic material, the adhesive can be a solvent that
forms a tacky area when applied to the label or the
container. This allows the label to be attached to
the container for a short but sufficiently long time
for the labels to be wrapped around the container but
which provides for part of the adhesive effect to be
dissipated after a few minutes or after longitudinal
edges of the label are subjected to heat radiated from
an electric heating element or from a jet of hot air
projected on the edges of the label while the contain-
er is still rotating.
In any case, when only a short time elapses
between completion of the label wrapping step and heat
sealing the overlapping ends of the label, it is nec-
essary that the trailing edge of the label remains on
the container during that time. This is achieved by
mechanically pressing the label against the container,
for example, or preferably by attaching the label to
the container tentatively with narrow adhesive strips
applied in the region just behind the trailing edge
but with overlapping leading and trailing edges, which
are to be subject to heat sealing, kept free of adhe-
CA 02244779 1998-09-14
i
-- 6 --
sive. The advantage of having the adhesive near the
trailing end of the label but not extending to the end
is that only one layer of adhesive, the layer on the
leading end, lies in the region where the ends overlap
for heat sealing. The result is a more inconspicuous
seal which is one objective of the invention.
When applying labels whose upper and lower
longitudinal edges do not follow the contour of the
container after the label is wrapped, it is advanta-
geous for the unadhered lower and upper edge or edges
of the label to be backed up or supported on the in-
side facing the container so that the overlapping ends
of the label can be sealed along the full height or
width of the label. This assures that the upper and
lower edges of the label in the region of overlapping
will not separate or split open when the edges are
subjected to heat shrinking.
An important feature of the invention is
that the sealing time for the labels can be held con-
stant independent of the present operating speed of
the machine. This allows the labeling machine to be
incorporated into a production line which has preced-
ing and subsequent processing stages without the qual-
ity of the sealed seam being adversely affected, that
is, without the application of too much or too little
heat when there are variations in the operating speed
at the input or output side of the new labeling ma-
chine.
How the foregoing briefly mentioned features
of the new labeling method, resulting article and ma-
chine are achieved and implemented, will appear in the
following more detailed description of a preferred
embodiment of the invention wherein reference is made
to the accompanying drawings.
CA 02244779 1998-09-14
Description of the Drawings
FIGURES 1-4 are schematic top plan views of
the new labeling machine with its cover removed and
respectively depicting four different embodiments of
the invention'
FIGURES 5-7 show cross-sections through the
overlapping leading and trailing ends of a label con-
tainer wherein there are, respectively, different ad-
hesive patterns;
FIGURE 8 is a perspective view of a label
container which has an adhesive pattern on the label
corresponding with the pattern shown in FIGURE 6;
FIGURE 9 shows a vertical section through
the outer rim or periphery of the turntable of a la-
beling machine, such as in FIGURES 1-4, showing how
the container is subjected to an axially downwardly
applied axial force which holds it firmly to a rotat-
ing disk, this figure also illustrating how the upper
longitudinal edge of a label which extends over the
inwardly tapered part of the container is backed up
with an element which prevents the upper edge of the
label from collapsing inwardly when the overlap is
being sealed; and
FIGURE 10 is a diagram used for illustrating
and explaining that the radius of curvature of the
heat sealing member where it interfaces with the label
on the container being sealed is greater than the ra-
dius of curvature of the container.
Description of a Preferred Embodiment
The labeling machine illustrated in FIGURE
1 has a turntable 15 which is driven rotationally
about a vertical axis and carries several rotationally
driven plates 16 which are shown in dashed line cir-
cles where they are not supporting a container 1 which
is to be labeled. One of the dedicated control devic-
CA 02244779 1998-09-14
es 20, depicted only in FIGURE 9, which causes the
respective rotary plates 16 to undergo a particular
rotational sequence during a revolution of turntable
15. The containers 1 to be labeled are transferred to
the rotary plates 16 in succession from a circular
infeed conveyor 17 which is shown schematically.
There is a conventional centering container stabiliz-
ing bell 19, shown in FIGURE 9, for each rotary plate
16. The centering bell 19 can be raised and lowered
with the help of which containers 1, after being
transferred from infeed conveyor 17, are clamped with
an axially directed force to the associated container
supporting rotary plate 16.
Positioned in the region directly behind the
infeed conveyor 17, radially outwardly of clockwise
rotating turntable 15, is an adhesive applicator 12,
commonly called a glue roller, which applies a strip
of glue directly on the passing containers 1. The
adhesive applicator 12 is basically a rotating roller
which, when glass bottles or metal cans are the con-
tainers, applies preferably hot adhesive to the con-
tainer or label or applies a solvent to the container
or label when the container is composed of plastic
material. The adhesive pattern formed on the contain-
er or label by the applicator 12 depends on the con-
figuration of the surfaces of the container and the
adhesive roller. If the body of the container and the
periphery of the adhesive applicator roller are cylin-
drical, they make a tangential contact along a line
which results in a narrow vertical strip of adhesive
being transferred to the container. When hot melt
adhesive is used, it is only necessary to apply adhe-
sive to a few points to the leading edge of the label
to hold it in place so that the adhesive applicator
roller will have several projecting annular lands, not
CA 02244779 1998-09-14
visible, axially spaced apart one above the other.
The resulting glue pattern in such case is illustrated
by the three adhesive strips depicted in FIGURE 8.
Upstream of glue applicator 12 in the rota-
tional direction of the turntable 15, a label transfer
device 9 is positioned for depositing individual la-
bels 2, which have been separated from a roll of la-
bels, on containers 1. The label transfer device 9 in
this particular embodiment constitutes a rotationally
driven vacuum cylinder 14 which rotates synchronously
with turntable 15 and, in this embodiment, in the same
direction. The labels 2, which are cut to size al-
ready, cling to vacuum cylinder 14 after having been
separated from an incoming web of labels by a cutting
device 7 positioned adjacent the vacuum cylinder 14.
The web is fed through web delivery pinch rolls 6 at
a rate which is synchronous with the machine output
from a supply roll, not shown, so that the labels 2
are positioned with their graphics facing the vacuum
cylinder. The device which severs the individual la-
bels from the web consists of a stationary blade 29
and a rotating blade 30 on the rotating vacuum cylin-
der.
Oppositely of the main vacuum cylinder 14
and radially inwardly of the rotary plate 16 orbit 23
there is a curved stationary guide element 21 whose
outer surface lies adjacent the containers 1. As the
labels 2 are wrapped about the containers in succes-
sion, guide element 21 guides the free end of the la-
bel which is not yet on the container 1 and simulta-
neously pulls the label taut so that it fits tightly
on the container. The guide element 21 is preferably
supplied with vacuum orifices, not shown, to enhance
attraction of the labels. The length of guide element
21 is such that its downstream or trailing end guides
CA 02244779 1998-09-14
-- 10 --
the trailing end of the label at least until the label
is completely wrapped around the container such that
the overlap between the leading and trailing ends of
the label is formed in the region 3 which is identi-
fied in FIGURE 8.
Radially inwardly of the rotary plate 16
orbit 23 is a circular guide frame 28, shown in sec-
tion, which holds radially reciprocable heat sealing
members 22. Guide frame 28 rotates in synchronism
with turntable 15. The number of heat sealing members
22 carried on guide frame 28 corresponds to the number
of rotary plates 16 on turntable 15. The sealing mem-
bers 22 are positioned to cooperate with the respec-
tive rotary plates 16. There is an electric heater
cartridge 37 on each sealing member. Positioned in-
side of the guide frame 28 is a control device 24
which drives the heat sealing members 22 radially out-
wardly. Control device 24 comprises first and second
superimposed radial cams 25 and 26 which are adjust-
able rotationally in relation to each other in the
rotational direction of turntable 15 or in the oppo-
site direction. Each heat sealing member 22 has on
its radially inward end a guide roller 27 which is
spring biased into contact with radial cams 25 and 26.
The spring which holds each roller in contact with
cams 25 and 26 is not shown.
The first or upper radial cam 25 of control
device 24 is held stationary on a central machine sup-
port 31 in this embodiment while the lower or second
radial cam 26 is rotationally adjustable about sta-
tionary center support 31 by means of an actuation
device, not shown, between two limit positions. The
upper or first radial cam 25 determines the beginning
of the heat sealing step by forcing a heat sealing
member 22 radially outwardly into contact with the
-
CA 02244779 1998-09-14
label overlap, while the trailing edge of the lower or
second radial cam 26 determines the end of the heat
sealing step. Offsetting the lower cam 26 relative to
the upper cam 25 enables the turntable rotational an-
S gle during which a heat sealing member 22 bears on the
overlapping trailing and leading label ends in the
region 3 of label 2 to be enlarged or reduced in size
in proportion to the present rotational speed of turn-
table lS. Because the second or lower radial cam 26
is continuously adjustable within limits, the sealing
time can be kept constant within limits by varying the
control angle. In other words, the heat application
angle is increased or largest when the output rate is
high and is reduced as the output rate decreases.
The advancing edge of the first or upper cam
2S is positioned so that the sealing members 22 are
pushed radially outwardly shortly before the trailing
end of the fixed guide element 21 is reached and are
applied to the overlapping end region 3 of a label 2
immediately beyond the end of guide element 21. The
edge of the lower or second radial cam 26 begins
shortly before the outfeed conveyor 18 is reached, and
at the latest, so that the heat sealing members 22 can
be pulled by spring action radially inwardly again to
provide for removal of containers 1 from turntable 15
and for transferring of the containers to outfeed con-
veyor 18. At the moment transfer of a container from
the turntable to the outfeed conveyor 18 occurs, the
~entering bell 19, depicted in FIGURE 9, is lifted so
that the container is free to be carried away on the
outfeed conveyor.
The rotational or oscillation sequence of
the container support plates 16 is such that a con-
tainer 1 is set into rotary motion counter to the
turntable lS after passing the adhesive applicator 12
CA 02244779 1998-09-14
, '~
- 12 -
or upon reaching the label transferring vacuum cylin-
der 14, at the latest. After termination of the label
wrapping step resulting from at least one complete
revolution of the container, the rotary motion of the
container relative to the turntable 15 stops for the
sealing step with the overlapping label end region 3
pointing inwardly toward the sealing member 22 which
is traveling along with it. In other words, the heat
sealing member 11 is maintained in contact with the
region 3 in which the leading end of the label is
overlapped by the trailing end after the turntable
orbits the container beyond guide 21. It should be
remembered that the trailing end of the label will not
have adhesive directly on it in the overlapping or
sealing region and that the adhesive applied to the
leading end is set back out of the overlapping region
by a small amount.
The alternative embodiment of the new label-
ing machine depicted in FIGURE 2 is basically the same
as that shown in FIGURE 1 but differs in respect to
the motion relationships in the area of the label
transfer device 9 and in the wrapping of the labels
around containers 1. In contrast to the FIGURE 1 em-
bodiment, the vacuum cylinder 14 in the FIGURE 2 em-
bodiment is driven counter-rotationally to the direc-
tion of turntable 15. In other words, in FIGURE 2 the
turntable 15 is rotating clockwise and the vacuum drum
14 is rotating counterclockwise. In this case, at the
moment of label transfer from vacuum cylinder 14 to a
container 1 and during subsequent wrapping of the la-
bel around the container, the container is moved by
rotary plate 13 in the rotational direction of the
turntable so that a container 1 is rolled slip-free on
the vacuum cylinder 14 when the leading edge of the
label is delivered. Because the containers 1 rotate
CA 02244779 1998-09-14
in the same direction as the turntable 15 in the FIG-
URE 2 embodiment, the stationary guide element 21 is
positioned radially outwardly.of the container orbit
which is outlined by the dashed circular line 23.
The FIGURE 2 embodiment makes it possible to
process labels which are longer than those which can
be handled in the FIGURE 1 embodiment with a turntable
15 having the same divisional scale and it offers more
favorable transfer conditions at the vacuum cylinder
14.
Since the electrically heatable sealing mem-
bers 22 are positioned radially inwardly of the rotary
plate orbital path 23, as in the FIGURE 1 embodiment,
but the overlap region at the ends of label 2 point
radially outwardly after wrapping the label, the con-
tainer must be turned at least 180~ for sealing, so
that the overlapped region is positioned opposite of
a heat sealing member 22. To prevent the trailing
edge 5 of the label from falling off the container
during the 180~ of rotation, it must be attached to
the container until the sealing member 22 is pressed
against the label overlapping ends of the container.
For instance, attachment of the trailing end of the
label to the container can be achieved mechanically by
a method, not shown, wherein a pressing or guiding
element is provided for each rotary plate and contain-
er 1 thereon and revolves with them and is applied to
the container at least by the time the container
reaches the departing end of the stationary guide ele-
ment 21, to hold the trailing part of the label 2 on
the container until the overlap region 3 is aligned
with and contacted with a sealing member 22. A press-
ing or guiding element, not shown, of this kind is
mounted for radial movement on circular guide frame 28
and actuated by an associated control device, not
CA 02244779 1998-09-14
shown, slmllar to the control devlce deplcted ln FIGURE g for
actuatlng heat seallng members 22.
Alternatlvely, the tralllng edge 5 of the label 2
can be held on the contalner by attachlng the tralllng edge
slmllarly to the leadlng edge, but wlth a narrow adheslve
reglon or polnts, applled before the overlap reglon 3 of the
label 2 ls secured by seallng. In other words, the adheslve
dots or llne ls applied near the tralllng edge but not so
close to the tralllng edge as to be colncldent wlth any part
of the area at the tralllng edge whlch overlaps the leadlng
edge. In comparlson to the FIGURE 1 embodlment, thls
modlflcatlon requlres no addltlonal mechanlcal parts. When
the leadlng edge 4 of the label ls applled to contalner 1 by
vacuum cyllnder 14, the rotatlon of the contalner 1 wlth
rotary plate 16 must merely be ad~usted relatlve to rotatlon
of the vacuum cyllnder 14 ln the area of the transfer devlce 9
so that leadlng edge 4 of the label does not completely cover
the adheslve strlps prevlously applled to the contalner by the
adheslve appllcator 12 for attachlng the label to the
contalner. Thus, part of the adheslve applled to the
contalner for attachlng the leadlng edge of the label ls
exposed. Thls not yet covered part of the adheslve strlp or
strlps ls contacted by the tralllng edge 5 of the label at a
dlstance from the extremlty of the tralllng edge durlng
subsequent wrapplng but the overlapplng reglon 3 ls kept free
of adheslve for subsequent heat seallng although there ls a
slngle layer of adheslve between the leadlng end of the label
and the contalner. (See FIGURES 6 and 8).
Another alternatlve embodlment ls lllustrated ln
- 14 -
60895-1469
CA 02244779 1998-09-14
FIGURE 3. It dlffers from the FIGURE 2 embodlment ln that lt
has a dlfferent heat seallng devlce 11. The heat seallng
devlce ln FIGURE 3 ls a curved heatlng element 32 whlch ls
held statlonarlly radlally outward of the orbltal path 23 of
the contalners and ls enclrcled by a thln, heat reslstant but
heat transmlsslve bèlt 33 of fllm-llke materlal such as that
-14a-
608g5-1469
CA 02244779 1998-09-14
- 15 -
which is known by the trademark TEFLON. The belt 33 is
diverted or directed by deflection rollers 34 and 35
at each end of the heating element. The deflection
roller 35 iS driven rotationally synchronously with
the current rotational speed of turntable 15 SO that
belt 33 bears against container 1 and travels slip-
free with it.
The process of wrapping a label 2 on a con-
tainer 1 in the FIGURE 3 embodiment is the same as in
the FIGURE 2 embodiment, for example, until the aft
end of the guide element 21 iS reached. However, af-
ter wrapping a label on a container is complete, the
rotary motion of container 1, activated by a control
device 20 of the rotary container support plate 16, is
stopped near the aft end of the guide element 21 SO
that the region 3 where the ends of the label overlap
faces radially outwardly of the turntable and in this
position is conducted past the heat sealing device or
element 11 while the container is orbiting with the
turntable but it is not rotating relative to the turn-
table.
As shown in the FIGURE 3 embodiment, heat
sealing can be apportioned between one or more heating
elements 11 which are positioned in succession on the
turntable adjacent the course 23 followed by the ro-
tating containers. The heating elements can be shift-
ed away from the containers radially outwardly with
actuation devices, not shown, to adapt the sealing
rate to different machine outputs. At full capacity,
both heat sealing elements 11 assume their radial in-
side position, whereas at half capacity, for instance,
one element 33 is shifted radially outward or
deenergized to avoid overheating. This allows at
least one-step adaptation of sealing time to different
machine output. If the labeling machine should fail
CA 02244779 1998-09-14
to stop because of a malfunction, all heat sealing
members 11 can be shifted to the outer disengaged po-
sition simultaneously.
In the FIGURE 4 embodiment of the labeling
machine, the sealing device consists of several heated
sealing rollers 36 positioned in staggered sequence
inside and outside of the container orbit 23. In con-
trast to the previously described embodiments, the
containers 1 are still continuously rotated about
their own axes in the same direction by the control
device for the rotary plate 16, even after completion
of the wrapping process, as they travel through the
sealing region. The stationary heatable sealing roll-
ers 36 are positioned in staggered sequence on the
turntable 15 so the overlapped region 3 is always
briefly pressed by one of the sealing rollers 36 in
- alternation when it faces the respective radial inside
or outside. To avoid slipping between the label sur-
face and the surface of the sealing rollers 36, the
rollers are driven synchronously with the speed of the
label surface which is clinging to the container. By
means, not shown in detail, the sealing rollers 36 can
be drawn away from the containers radially inwardly or
outwardly, respectively, so that the sealing time can
be adapted to the present output of the labeling ma-
chine or to the operating speed of turntable 15 as is
the case in the FIGURE 3 embodiment.
FIGURES 5-7 show a section through a part of
a container where the leading and trailing ends of the
label overlap. In these figures, sealing of the label
ends is completed. The three embodiments in FIGURES
5-7 differ only in respect to the adhesive regions 13
used on the labels 2.
In the FIGURE 5 option, only the leading
edge 4 of the label is attached to the periphery or
CA 02244779 1998-09-14
- 17 -
outside of the container wall 38 through narrow adhe-
sive regions 13. The trailing end of the label is
held to the leading end exclusively by the heat seal
in the overlap region 3. It will be understood that
the adhesive region 13 can be shifted laterally a cer-
tain distance from the leading edge of the label so it
no longer lies directly in the overlapping region 3.
As is also shown, the trailing edge 5 in FIGURE 5 can
be sealed to the leading edge of the label by a seal-
ing member 22 that is movable radially in relation to
container 1 and can be adjustably heated by previously
mentioned rod-shaped electric heating cartridge 37.
To prevent the label material from sticking to the
sealing member 22 due to the heat of the sealing pro-
cess, at least the part of the sealing member which
interfaces with the label surface can desirably be
coated with TEFLON. The sealing effect is influenced
not only by the adjustable and controllable tempera-
ture of the sealing members 22 but also by the pres-
sure of the members against the container. The seal-
ing members 22 are therefore biased by springs, not
shown, which at the same time compensate for tolerable
variations in the diameters of the containers which
may occur.
In the FIGURE 6 embodiment, the adhesive
region 13 holds not only the leading edge 4 but also
the aft section of the label 2 in the vicinity of its
trailing edge 5 to the container wall 38, although the
overlap region 3 between the trailing edge 5 and lead-
ing edge 4 of the label remains free of adhesive.
This is necessary to achieve a flawless seal. The
adhesive pattern in FIGURE 6 is also discernable in
FIGURE 8. It is not absolutely necessary that a con-
tinuous vertical line of adhesive be applied parallel
to the leading edge 4 of the label to obtain satisfac-
CA 02244779 1998-09-14
~ , ,
- 18 -
tory adhesion and wrapping. Two or three narrow, ver-
tically aligned and slightly horizontally extending
adhesive stripes or dots are sufficient. These can be
applied with an adhesive roller 12 having radially
projecting annular lands acting directly on the con-
tainers or with spray nozzles, not shown.
The application of adhesive only at certain
points or dots, as indicated in FIGURE 8, can also be
used with the adhesive arrangement of FIGURES S and 7.
FIGURE 7 shows an adhesive pattern similar to that of
FIGURE 6 but differs in that no adhesive is applied
between the leading edge 4 of the label and the con-
tainer wall 38 in the overlapped region. Each adhe-
sive region 13 is a certain distance from the leading
edge 4 or the trailing edge 5 of the label. The ad-
vantage of this is, because there is no superimposed
mass of material and adhesive, the overlapping region
3 lies tightly against the container wall 38 after it
is sealed which makes a less visible or invisible
seal.
The adhesive patterns of FIGURES 5-7 can be
applied, not only directly onto the container, as
shown in the FIGURES 1-4 embodiments, but also direct-
ly on the corresponding regions of the inside surface
of the label. The adhesive roller or applicators re-
quired for this must then be positioned on the periph-
ery of the vacuum cylinder 14. The separated individ-
ual labels 2 are held inside out on the vacuum cylin-
der. To obtain the adhesive pattern of FIGURE 5, for
example, the vacuum cylinder 14 may have radially mov-
able slides, not shown, in proximity with the leading
edge of the label so that a smooth adhesive roller
with minimal radial interspace can be placed on the
vacuum cylinder 14 to apply adhesive to the leading
edge 4 of the label. These slides can also be used to
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transfer the leading edge 4 of the label from the vac-
uum cylinder 14 to the container 1 as the container is
conveyed past it on the turntable 15.
In FIGURE 8, the label 2 is attached to the
container wall 38 of container 1 using the adhesive
pattern of FIGURE 6. Although the label 2 is held to
the container wall 38 only at certain points by three
narrow adhesive strips or dots 13 applied one above
the other near the leading end of the label, the
trailing end of the label is sealed continuously along
its entire length to the leading end.
In processing containers having radially
tapered sections at the top or bottom that are to be
covered by a label that fits the container contour
after the labeling process is complete, the label can
be attached first directly to the cylindrical part
with the narrow adhesive regions unwrapped by the pre-
viously described method. Then to seal the overlapped
region, a support is needed on the inside of the over-
lap where it is not yet in contact with the outer con-
tainer wall after wrapping so that it can be sealed
along its entire length. After sealing, the extending
portions of the label can be shrunk to the container
contour by means of heat confined to the extending
portions.
FIGURE 9 shows a container 1 clamped axially
between a rotary plate 16 and a centering bell 19
where the upper edge of the label extends upward be-
yond the cylindrical region of the container which is
clamped between the top and bottom. To support the
overlapped region 13 in this extending part of the
label, a support surface designed in the form of a
tongue 39 is mounted on the centering bell 19.
Attention is invited to FIGURE 10 for a dis-
cussion of manner in which the hot curved surface 41
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of heating element 22 interfaces with the overlapped
label ends on container 1. The container 1 is shown
as a solid line circle that has a radius RG. The ra-
dius of the heater element surface 41 is RS which is a
little greater than RG. The heater element face 41 is
an arc of the phantom line circle which is an extrapo-
lation of the arc. Thus, the center of the heater
element surface makes contact with the label on con-
tainer 1 about where the lead line from the numeral 41
touches the container. This makes the sealed label
overlap area less conspicuous which is desirable.
