Note: Descriptions are shown in the official language in which they were submitted.
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PROCESS FOR PRODUCING A CONTAINER
HAVING A RESEALABLE CLOSURE
Field Of The Invention
This invention relates to a process for producing a container
having a resealable closure and more particularly to a process for
producing a paper container closed at one end with a membrane disc and
a paper overcap which may be used for resealing the container after
opening thereof through the membrane.
Background Of The Invention
Containers have heretofore been provided for dry products
l0 including food, various powdered and the like products which have
comprised a container body portion constructed primarily of paper, a heat
sealable membrane closure on one end thereof and a plastic overcap
covering the membrane closed end so that when the membrane is broken
to obtain access to the product in the interior of the container, the plastic
overcap may be used to reclose the container. Reference may be had to
United States Patent 3,892,351 of July 1, 1975 for a general description of
this type of container.
While this type of container has well served its purpose for
packaging various types of products, it does not provide a container having
2 0 an overcap constructed generally of the same materials as the container
for
recycling or other purposes. Paper overcaps have not been considered
practical for these types of containers primarily because of the expense of
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producing this type of container with a paper overcap when compared to
producing this type of container with a plastic overcap.
Obiect And Summary Of The Invention
Accordingly, it is the object of this invention to provide an
improved process of producing a container having a resealable closure
which makes it practical from a manufacturing and cost standpoint to
fabricate an overcap and a container from generally the same materials
(preferably and primarily paper).
It has been found by this invention that this object may be
accomplished by providing such a manufacturing process for a container
having a resealable closure which includes the following steps. A hollow
container of desired shape and having an open upper end of desired
dimensions is provided. An overcap substrate is provided. A heat sealable
membrane disc of desired shape and dimensions is provided to cover the
open upper end of the hollow container. The membrane disc is laminated
to the overcap substrate with a material which releases the membrane disc
from the overcap substrate under the application of heat. Thereafter, an
overcap of desired shape and dimension is fabricated to fit over the open
upper end of the hollow container from the substrate with the membrane
disc on the inside thereof. The overcap is then positioned over the open
upper end of the hollow container so that the membrane disc is in contact
with and covers the open upper end of the container. Heat is applied to the
overcap to effect heat sealing of the membrane disc to the upper end of the
container to hermetically seal such container end and to effect release of
the membrane disc from the overcap.
Preferably, the composite container is cylindrical and includes
a paperboard body portion and a heat sealable liner and has an outwardly
beaded open upper end of desired dimensions. Preferably, the overcap
substrate includes a paperboard material for fabricating a paperboard
3 o overcap.
Optionally, the process of this invention may include
permanently bonding a desired area of the membrane disc to the overcap
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so that a bond remains therebetween after heat release of the membrane disc
from the overcap to provide a tamper evident means.
According to one aspect of the invention, there is provided a
process for producing a container having a resealable closure comprising the
steps of providing a hollow container of desired shape and having an open
upper end of desired dimensions; providing an overcap substrate; providing a
heat sealable membrane disc of desired shape and dimensions to cover the open
upper end of the hollow container; laminating the membrane disc to the
overcap substrate with a material which releases the membrane disc from the
overcap substrate under the application of heat; fabricating an overcap of
desired shape and dimensions to fit over the open upper end of the hollow
container from the substrate with the membrane disc on the inside thereof;
positioning the overcap over the open upper end of the hollow container so
that
the membrane disc is in contact with and covers the open upper end of the
container; and applying heat to the overcap to effect heat sealing of the
membrane disc to the upper end of the container to hermetically seal such
container end and to effect release of the membrane disc from the overcap.
According to another aspect of the invention, there is provided a
process for producing a container having a resealable closure comprising the
steps of: providing a generally cylindrical hollow composite container
including a paperboard body portion and a heat sealable liner and having an
outwardly beaded open upper end of desired dimensions; providing a
paperboard overcap substrate; providing a heat sealable membrane disc of
suitable dimensions to cover the open upper end of the hollow cylindrical
container; laminating the membrane disc to the overcap substrate with a
material which releases the membrane disc from the overcap substrate under
the application of heat; fabricating a paperboard overcap of desired shape and
dimensions to fit over the beaded open upper end of the hollow container from
the substrate with the membrane disc on the inside thereof; positioning the
overcap over the beaded open upper end of the hollow container so that the
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membrane disc covers the open upper end of the container and is in contact
with the heat sealable liner; and applying heat to the overcap to effect heat
sealing of the membrane disc to the liner in the beaded upper end to
hermetically seal the container end and to effect release of the membrane disc
from the overcap.
Brief Description Of The Drawings
Some of the objects and advantages of this invention have been
set forth above, other objects and advantages will appear from the following
detailed description of a preferred embodiment of this invention, when taken
in
conjunction with the accompanying drawings, in which:
FIG.1 is a perspective exploded view of a container having a
resealable closure and constructed in accordance with the process of this
invention and illustrating the user removing product contents from the
container;
FIG. 2 is an enlarged sectional exploded view and taken generally
along the line 2-2 of FIG. 1;
FIG. 3 is a schematic view illustrating some of the steps of the
process of this invention;
FIG. 4 is an enlarged partial perspective view of the overcap
substrate with membrane disc laminated thereto and taken generally along the
line 4-4 of FIG. 3;
FIG. 5 is a further enlarged sectional view through the overcap
substrate and membrane disc and taken generally along the line 5-5 of FIG. 4;
FIG. 6 is an enlarged partial sectional view through a fabricated
overcap having a membrane disc laminated on the inside thereof and taken
generally along the line 6-6 of FIG. 3;
FIG. 7 is an enlarged partial sectional view through a container
having the membrane disc heat sealed to the upper end thereof to hermetically
seal such open end and having the overcap positioned over such open end and
taken generally along the line 7-7 of FIG. 3;
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FIG. 8 is a view, like FIG. 7 and illustrating an alternative feature
of a bond between a desired area of the membrane disc and the overcap to
provide a tamper evident feature; and
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FIG. 9 is a view, like FIG. 8 illustrating the overcap being
removed from the container resulting in a tear of the membrane at the bond
to show the tamper evident feature in operation.
Description Of Preferred Embodiments Of The Invention
Referring now to the drawings and particularly to FIGs. 1 and
2, a container 10 is illustrated which is produced in accordance with this
invention. This container 10 is of desired shape, preferably cylindrical, and
has an open upper end 11 of desired shape, preferably circular. The lower
end of the container 10 may be closed by any suitable closure as well
understood by those with ordinary skill in the art and does not form a part of
the present invention and will not be described in detail herein. The open
upper end 11 of the container 10 is hermetically sealed by a heat sealable
membrane disc 12 of desired shape, preferably circular, and dimensions to
cover the open upper end 11 of the hollow container 10. An overcap 13 of
desired shape, preferably circular with a depending peripheral flange, and
dimensions is provided to fit over the open upper end 11 of the hollow
container 10 and is adapted to be removed for breaking the membrane 12
to gain access to the product P within the container 10 and to then be
positioned back over the open upper end 11 of the container 10 to reclose
the container.
The container 10 is preferably constructed of composite
materials and includes a cylindrical open ended body portion 15 which may
be preferably constructed of one or more paperboard body plies 16 which
may be spirally or convolutely wound or otherwise formed. These
2 5 paperboard body plies 16 are typically formed of spiral-winding paperboard
or board stock having a thickness of between 0.010 and about 0.035 inch,
preferably between about 0.015 and 0.030 inch, for example 0.021 inch.
The board stock conventionally used in the manufacture of spirally-wound
composite containers is commercially available from various manufacturers
including Sonoco Products Company, Republic Paperboard Corporation
and Middletown Board Corporation. In order to function advantageously as
the spirally-wound bodywall layer, the board stock typically is composed of
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Kraft or recycled paper and can typically range from, e.g. 50 to 100
Ibs./ream. In some instances, the board stock can include a weak exterior
layer, e.g. a 0.003 inch exterior news. The body portion 15 of the container
may further include a heat sealable liner layer 17 which is suitably
5 laminated to the body ply 16 and may be spirally or convolutely wound or
otherwise formed with the body ply 16 into the open ended hollow
container body portion 15. The liner layer 17 may be typically constructed
of a barrier type, flexible sheet material, such as a polymer/foil, a
Kraft/foil/polymer, a polymer/polymer, or a Kraft/foil laminate. The
l0 container body portion 15 may also include an outside label layer (not
shown) if desired. The open upper end 11 is outwardly beaded in a
manner well understood by those with ordinary skill in the art so that the
liner layer 17 is positioned on the outer surface of the outwardly beaded
open upper end 11 (as shown in FIG. 2). The overcap 13 may preferably
be constructed of one or more paperboard plies 18 which are also typically
formed of similar materials as described above for the paperboard body
plies 16. The heat sealable membrane disc 12 may suitably be constructed
of a laminate of polymer and paper layers with or without foil.
In order to manufacture or produce this container 10 from an
economical and practical standpoint, the novel process ofithis invention is
utilized and which is illustrated more specifically in FIGs. 3-7. Firstly, the
hollow container body portion 15, as described above, is provided having
the open upper end 11. An overcap substrate material 20, which may be
constructed of the paperboard plies 18, is provided. Heat sealable
2 5 membrane discs 12 of the desired shape and dimensions to cover the open
upper end 11 of the container body portion 15 are provided. These heat
sealable membrane discs 12 are laminated to the overcap substrate 20
with a material 21 which release the membrane disc 12 from the overcap
substrate 20 under the application of heat. This heat releasable material
3 o may be in the form of a polymer, hot melt or wax material.
Next, an overcap 13 of desired shape and dimensions to fit
over the open upper end 11 of the hollow container body 15 is fabricated
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from the substrate 20 with a membrane disc 12 on the inside thereof (as
shown in FIG. 6). Commercially available overcap forming equipment, well
known to those with ordinary skill in the art, may be utilized for such
overcap forming operation. Such equipment is available from a number of
sources including Michael Hbrauf Maschinenfabrik GmbH & Co. KG. The
thus fabricated overcap 13 is positioned over the open upper end 11 of the
hollow container body 15 (as shown in FIGs. 3 and 7) so that the
membrane disc 12 is in contact with and covers the open upper end 11 of
the container body portion 15. Heat is then applied with any suitable
l0 device, schematically illustrated at 31, to the overcap 13 to effect heat
sealing of the membrane disc 12 to the upper end 11 of the container 10
and preferably to the heat sealable liner layer 17 of the outwardly beaded
open upper end 11 to hermetically seal the container end 11 and to effect
release of the membrane disc 12 from the overcap 13. This release is
caused by melting, evaporating or otherwise eliminating the releasable
material 21 between the overcap 13 and the membrane disc 12 (as shown
in FIG. 7).
In accordance with an alternative feature of this invention (as
illustrated in FIGs. 8 and 9), a permanently bonded area 35 may be
2 o provided between the overcap 13 and the membrane disc 12 so that a
bond remains therebetween after heat release of the membrane disc 12
from the overcap 13 to provide a tamper evident feature or means in the
container 10. With this permanently bonded area 35, when the overcap 13
is removed from the container 10 a portion of the membrane disc 12 will be
2 5 torn and remain with the overcap 13 (as shown in FIG. 9) to evidence that
the overcap has been removed from the container and to provide the
tamper evident feature.
The above described container 10 and its novel process of
manufacture produces a container product which is normally sold by the
30 container manufacturer to a customer who fills the container 10 with the
desired product P and closes the bottom or other end of the container 10
with a suitable closure.
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Heretofore, in the manufacturing processes for these types of
containers, which commonly utilized a composite container body portion
and a plastic overcap, additional manufacturing steps were necessary
which added to the cost of producing the container. The membrane disc
12 had to be separately positioned and applied to the open upper end 11 of
the container body portion 15 and heat sealed thereto, while the plastic
overcap was formed in an entirely separate manufacturing operation.
These separate operations also required that the membrane disc 12 be
made of a material which provided more body and stiffness thereto and the
less expensive thinner membrane materials could not be used from a
practical standpoint in these prior manufacturing operations. By combining
the membrane disc and the overcap substrate into one material prior to
forming of the overcap, these manufacturing processes have been greatly
reduced and simplified, resulting in a substantial cost savings which
renders practical the use of overcaps preferably constructed of paperboard
material and of the same material as the container body portion.
While the novel process and resulting product of this
invention have been illustrated and described above in specific terms, it will
be obvious to those skilled in the art that various changes and
modifications can be made without departing from the spirit and scope of
this invention and it is intended to cover, in the appended claims, all such
changes and modifications that are within the scope of this invention
