Note: Descriptions are shown in the official language in which they were submitted.
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METHOD AND APPARATUS FOR
WRAPPING A LABEL ONTO A CONTAINER
WITH A GLUELESS LEADING EDGE
TECHNICAL FIELD
The present invention relates to a method and apparatus for labeling
containers .
BACKGROUND ART
Many different methods and machines have been developed for
applying labels to containers. Labeling containers has many advantages when
compared to directly decorating containers by painting or printing. Labeling
containers is generally less expensive and can provide a aesthetically
pleasing
container appearance that provides a convenient way to Iabel a container with
all
required information and decorative graphics.
One type of label is a pressure sensitive adhesive label that generally
provides a full coating of adhesive that is protected prior to application by
means of
a backing layer. The backing layer is removed from the label prior to
application
and the Iabel is adhered to the container by means of the adhesive on the back
of the
label. Another type of label is a preformed sleeve Iabel that is then slid
over one end
of the container and either glued or shrunk in place. Sleeve labels are
generally
made of more expensive materials and are difficult to form and assemble to a
container when compared to roll fed labels. Wrap around labels are applied to
containers by wrapping the label around a container after first adhering the
leading
edge with a trailing edge being secured by adhesive to the outside of the
leading edge
or the container wall.
2S Containers are frequently recycled by remelting or washing for reuse.
When recycling it is generally first necessary to remove the labels and glue,
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especially if they are different in composition from the container. Frequently
when
labels are removed, a glue residue remains on the container if the label is
glued to
the container. The value of recycled containers is increased if the containers
are free
of contaminants such as glue and label fragments.
During the labeling process, glue applied to container bodies can
result in wrinkling that may be caused by the glue affixing portions of the
label to the
container during heat shrinking while other portions of the container are
permitted
to move. Wrinkling can also be caused with full coating adhesive application
if the
glue layer is not of a consistent thickness. Applying labels to containers
with glue
also increases the amount of glue required for the labeling operation that
also
increases cost.
These and other problems and disadvantages associated with prior art
labeling methods and machines are addressed by the labeling machine and system
disclosed in this application.
DISCLOSURE OF INVENTION
According to the present invention a machine for labeling containers
is disclosed that includes a container infeed conveyor for feeding containers
into the
machine. A label feeder supplies labels having a leading edge portion and a
trailing
portion from a label supply source. A vacuum drum receives labels from the
label
feeder. A wetting solution applicator is disposed on the labeling machine near
the
infeed conveyor for applying an aqueous solution to each of the containers as
they
are fed into the machine by the infeed conveyor. The solution is applied to a
label
panel portion of each container. A glue applicator is disposed adjacent the
vacuum
drum and has protruding portions spaced about the periphery of the vacuum drum
corresponding to the trailing edge portions of the labels. The protruding
portions
cause the trailing edge portions to contact the glue applicator thereby
coating the
trailing edge portions with glue. The vacuum drum applies labels to the
containers
by causing the aqueous solution on the containers to wet the labels causing
the labels
to wrap around the containers as they are separated from the cylindrical
surface of
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the vacuum drum. The trailing edge portion is wrapped onto the leading edge
portion of the labels and is secured to the leading edge portion of the labels
by glue.
According to another aspect of the invention, a method of labeling
containers is provided. The method comprises the steps of feeding labels
having an
inside surface and an outer surface to a labeling machine having a vacuum drum
for
supporting the labels during the labeling process. Containers having a label
panel
portion are fed to the labeling machine from a container supply source. An
aqueous
solution is applied to the containers to wet the label panel portion of the
containers.
Glue is applied to a limited portion of the inside surface of the labels while
the labels
are supported on the vacuum drum. The labels are wrapped about the containers
by
causing the aqueous solution on the containers to wet the inside.surface of
the labels.
The limited portion of the inside surface of the labels having glue applied
thereto is
secured to a portion of the outer surface of the label.
According to another aspect of the invention the label supply source
is preferably a roll of labels. Alternatively, the label supply source could
also be a
cut and stack label magazine or other label supply source.
The preferred wetting solution applicator is a roll-on pad.
Alternatively, the wetting solution applicator could be a spray applicator.
The glue applicator is preferably a hot melt glue applicator and the
glue applied is preferably hot melt glue. The hot melt glue is preferably
applied to
the trailing portion of the label in such a way that no glue is applied to the
container.
While in its most preferred form no glue is applied to the container, some
glue
spatter or a minimal quantity of glue could be applied between the label and
the
container but this glue is not intended to cause the transfer of the label to
the
container.
The method can also include the step of heating the label to shrink the
label material about contours or into reduced diameter portions of the
container.
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The above objects and advantages of the invention will be better
understood with reference to the attached drawings and following detailed
description
of the invention.
BRIEF DESCRIPTION OF DRAWINGS
FIGURE 1 is a partially plan view of a labeling machine and a partial
elevation view of an aqueous solution applicator system made in accordance
with the
present invention.
FIGURE 2 is an elevation view of a container having a label partially
applied thereto in accordance with the present invention.
FIGURE 3 is a plan view of a vacuum drum made in accordance with
the present invention.
FIGURE 4 is a cross-section view of a container having a label
applied thereto in accordance with the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
Referring now to FIG. 1, a labeling machine IO for labeling containers
12 is shown. Containers I2 are fed into the labeling machine 10 on an infeed
conveyor 14. Labels 15 are provided by a label feeder 16. The label feeder 16
may
incorporate a cutter I8 for cutting labels that are received from a roil of
labels 20
through a tensioner 22 as is well known in the art. Alternatively, the label
feeder 16
can be a cut and stack label magazine. A vacuum drum 24 is used to support
discrete
labels 15 after they are received from the label feeder 16 until they are
secured to the
containers 12.
As the containers are fed into the machine they are contacted by a
solution applicator 26 that is preferably in the form of a roll on pad. An
aqueous
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solution of water and from about 1 % to 5 % glycerine is supplied to the
solution
applicator 26 from a solution supply system 28. The solution supply system 28
includes a mixing tank 30 in which the water and glycerine is mixed in the
desired
proportion. Solution is provided to the solution applicator 26 by means of a
pump
32. A premix tank 34 is preferably provided to provide a reservoir of
glycerine in
a more concentrated form that is then diluted by a later addition of water
prior to
supplying it to the solution applicator 26. A mounting post 36 is provided on
the
labeling machine base for mounting the solution applicator to the labeling
machine.
Referring now to FIG. 2, a container 12 is shown with the label 15
partially pealed back to illustrate the wetting solution 40 on the label panel
portion
42 of the container 12. The label 1S has glue 46 applied to the label overlap.
Refernng to FIG. l, the glue applicator 50, preferably a hot melt glue
wheel applicator is shown adjacent the vacuum drum 24. Referring now to FIG.
3,
the vacuum drum 24 has a generally cylindrical surface 52. and is designed to
accommodate two to three labels. Protruding portions 54 are provided at spaced
locations about the perimeter of the cylindrical surface 52. The generally
cylindrical
surface includes undercut portions 56 in which a labeling segment is held on
the
vacuum drum 24. The vacuum drum cover 58 is preferably formed with Tygon, a
relatively rigid elastomeric material that can be machined to provide a
desired
contour.
Referring now to FIGS. 2 and 4, the label 15 is shown with its leading
edge portion 60 and trailing edge portion 62. The leading edge portion 60 is
the first
portion of the label 15 to contact the container while the trailing edge
portion 62 is
the last portion of the label to be transferred to the container 12 as the
label 15 is
applied. The trailing edge portion 62 is secured to the leading edge portion
60 by
hot melt glue 46.
The solution supply system 28 is described with reference to FIG. 1.
A tube 64 provides the aqueous solution, or wetting solution 40 to a sponge 66
that
forms part of the solution applicator 26. The sponge is preferably a PVA
sponge that
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is a durable, compressive material that retains the wetting solution for
transfer to the
container prior to labeling. A manifold 70 is provided to distribute the
aqueous
solution. A strainer (not shown) is provided to strain any foreign particles
from the
flow of aqueous solution prior to supplying it to the sponge 66. A pressure
regulator
is provided for controlling the fluid pressure in the solution supply system
28. A
valve 78 is provided to control the flow of the aqueous solution.
Referring now to FIG. l, as containers 12 are fed into the labeling
machine I0, they are initially guided by an infeed guide 80 and are fed into
the
machine in a timed relationship by means of a starwheel 82. A container guide
84
is located on the opposite side of the infeed conveyor 14 from the infeed
guide 80
and the solution applicator roll-on pad 26. As the containers follow the
container
guide 84 around the solution applicator 26, the containers 12 are rotated so
that
substantially the entire circumference of the container 12 becomes wetted by
the
aqueous solution. After the container 12 has been wetted with the aqueous
solution,
the container 12 is moved into contact with the label 15 on the vacuum drum
24. As
each container 12 moves around the vacuum drum, the label 15 is wrapped around
the container. A roll-on pad 86 is provided to hold the container 12 against
the
vacuum drum while permitting the container to rotate.
After the labels 15 are applied they may be heat shrunk onto the
containers by applying heat to the labels with a hot air blower or by passing
the
labeled container through an oven as is well known in the prior art.
While embodiments of the invention have been illustrated and
described, it is not intended that these embodiments illustrate and describe
all
possible forms of the invention. Rather, the words used in the specification
are
words of description rather than limitation, and it is understood that various
changes
may be made without departing from the spirit and scope of the invention.
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