Note: Descriptions are shown in the official language in which they were submitted.
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CONTAINER
FIELD OF THE INVENTION
The present invention is directed to a novel container for the
packaging of dispersion-based colorants to improve ease of use and
efficiencies of preparing colorants for final dispensing in paint formulating
centers.
BACKGROUND OF THE INVENTION
Currently, dispersion-based colorants, such as universal colorants,
are packaged in quart metal cans. The metal cans require a variety of tools
to be opened in order to fill colorant dispensers. Such colorant dispensers
are used to provide one or more colorants to a base paint to provide a paint
of a desired color. A common method used to open the metal cans of
universal, dispersion-based colorant is with the use of a carpet knife and a
"church key" type triangular can opener. This method of opening the cans
has exposed those employees who formulate the paint for the individual
consumer to potential injury. Additionally, both opening tools and methods
of use leave small openings in the top of the can from which the colorant
has to be poured. This results in slow addition time to the dispensers, does
not allow the metal containers to fully empty, and does, not allow for access
to properly clean the containers for environmentally sound disposal.
In the daily filling of the colorant dispensers, a large number of quart
containers are required. This process of refilling the dispensers requires a
considerable time commitment. Typically, prior to filling the dispensers, the
containers holding the colorant are shaken, such as in conventional paint
mixing equipment, to mix and provide a uniform colorant. Mixing in such
equipment takes about 3-5 minutes. If a full quart of colorant is not used,
the containers are stored until the next day. There is no way to reseal the
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partially filled open containers, subjecting the containers to potential
contamination, spillage, evaporation of components, and inability to remix.
Upon completion of filling all dispensing canisters, all the quart cans are
disposed of as normal waste. There is no ability to recycle.
"Plastics Technology -Online," October 2003, discusses new
technology to replace the ubiquitous one-gallon metal paint cans used by
professional painters and household consumers. From the article is
described the Sherwin-Williams Dutch Boy "Twist and Pour" gallon plastic
can, an extrusion blow molded HDPE container with a PP lid that is
presently commercialized. This advance was reinforced by the introduction
of a similar container by Masterchem, a supplier of primer paints that sells
topcoats in gallon and quart HDPE cans. These plastic containers are
square-bodied, rounded-lid, twist-top designs that fit more cans into
available shelf space, a priority for mass retailers. The new plastic
containers also incorporate ergonomic and convenience features for the
predominantly female paint consumer, including injection molded handles
and pour spouts, a recloseable screw cap that doubles as a paint cup, and
color-coordinated labels that help consumers pick the right paint. However
the new multi-part containers cost at least three times as much as the
typical steel gallon can. Further, the new plastic paint containers fit
awkwardly into the paint industry's current handling, filling, and tinting
infrastructure designed for round steel cans.
In early 2004, two firms are to launch new all-plastic concepts for
direct replacement of metal cans: an injection molded opaque, all-PP can
developed by KW Plastics of Troy, Ala., and an injection stretch-blow
molded clear, one-piece PET can from the PCC Group in the U.K. For
about a decade, KW Plastics has supplied mass-market paint companies
with millions of paint cans in a hybrid design that joins a PP body to a steel
ring and lid. KW now plans to launch an all-PP paint can by mid-2004. The
can body, ring, and lid will be of black, high-impact PP, though at first it
will
still have a snap-in metal handle. The can's crush-resistance reportedly
exceeds that of metal cans and is sufficient to stack containers up to 25
units high. Called "Snap Lock," the two-part gallon can uses an injection
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molded black PP body similar to that of hybrid cans and a separate
injection molded PP ring and lid. The shape of the can intentionally
parallels that of the steel version so that it can fit easily into existing
filling
lines and in-store shaker equipment. Injection molded, snap-in PP pour
spouts and handles are also in development.
The present applicants are not aware of any patents regarding
alternative containers to address colorant handling issues. Sherwin-
Williams offers colorant in a "F" style one-gallon plastic container. The "F"
style container is a duplicate of a gallon anti-freeze container. In order for
the colorant to be mixed, this container must be hand shaken. Those
instructions are specified on the label. It appears that no provisions have
been made for this container to be shaken with paint shaking equipment.
SUMMARY OF THE INVENTION
The present invention is directed to a new design for a family of
dispersion-based colorant containers to address the key issues and
objectives above. The design consists of a container extrusion blow
molded from HDPE (high density polyethylene). The new container
incorporates a wide opening having a diameter of at least 50 mm that
allows for a removable and replaceable screw top closure. The design has
the following advantages over the current metal quart containers in the
marketplace: (1) requires no tools to open, (2) resealable, (3) speed of
addition is improved with the wide opening. Tests have shown that the
time required to add colorant to paint dispensers can be reduced over the
current methods. For a quart container, pour times are reduced by 66-75%
(10-15 seconds) per container. Additional advantages include: (4) the wide
opening facilitates ease of cleaning the container for proper environmental
disposal, (5) material of construction is a recyclable plastic.
Further, the container does not contain a separate handle that needs
to be molded and/or attached to the container, but includes a hand grip
area molded in the container to provide for a more secure grip, reducing
potential for dropping containers and creating spills. The majority of metal
containers in the marketplace are cylindrical in shape with no grip area.
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The plastic container of this invention is cylindrical and has a circular
cross-
section from top to bottom. The container incorporates a circumferential
grip area of narrow cross-section on the outer container surface. The
circular shape of the container allows for multiple case handling and
shaking in current shaking equipment. A series of circumferentially spaced
ribs in the hand grip area reinforces the container and renders the plastic
container of this invention particularly useful in commercial paint mixers.
Thus, the present invention provides a plastic container for holding
liquids comprising a circular open top capable of closure by a separate cap
and a body portion extending from below said open top, the body portion
containing a gripping ring in the form of a reduced perimeter ring disposed
around the perimeter of the body portion, the circular top having a diameter
of at least 50 mm, the container being devoid of a separately attached
handle or any handle portion which extends laterally outward from the
container.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is an exploded plan view of the container of this invention
with cap.
Figure 2 is a plan view of the container of this invention with cap
placed on the container.
Figure 3 is an end view of the top of the container without cap
showing the circular cross-section.
Figure 4 is an alternative container to that shown in Figure 1, in
particular with respect to the shape of the circumferential shoulder.
Figure 5 is a plan view of another alternative container within the
scope of this invention.
DETAILED DESCRIPTION OF THE INVENTION
The present plastic containers may be used for holding liquids such
as dispersion-based colorants, personal care products, and foods. The
present containers may also be used for pumpable or pourable semi-solids.
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The present containers may also be used for pumpable or pourable semi-
solids.
The containers of this invention may be used to store and dispense
the liquids which are used to make customized personal care products from
5 a variety of bases. Such personal care products include those used in the
face, lip, and eye areas and in all external and rinse-off applications.
Examples include leg-makeup, insect repellent lotion, shampoos of all
types, bubble bath, body lotion (moisturizing, cleansing, analgesic,
astringent), after shave lotion, after bath milk, and sunscreen lotion.
In particular, the plastic containers of the present invention are
used for storing dispersion-based colorants, such as universal colorants,
generally containing over 10% pigment solids dispersed within a liquid
vehicle, typically a mixture of surfactants, so as to maintain the pigment
solids suspended in the liquid solution without separation. The containers
of this invention are used to store and dispense the liquid colorants into
paint dispensing machines which are used to make customized colors from
a variety of paint bases. The containers of the present invention provide
improvements in the daily filling of the colorant dispensers for paint
formation, as previously described. Thus, ease of opening, being
completely resealable, rapid filling speeds, easily cleaned for disposal and
being recyclable are useful properties of the containers of this invention.
Importantly, the plastic containers are provided with a strengthening feature
so that the container can withstand the forces extended on the container
during the typical mixing or shaking required to provide colorant uniformity.
An example of a paint container of the present invention is shown in
Figures 1 and 2 and is designated in general by reference numeral 10. The
container, for example in quart and one-half gallon size, is formed by
extrusion blow molding from high density polyethylene (HDPE). The
particular molding process for forming the paint container is not critical,
and
any known such method capable of forming the container 10 as described
below can be used in this invention. Extrusion blow molding, a process
well known in the art for forming hollow plastic structures such as
containers, is particularly useful. While HDPE is preferred, the container
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configuration of this invention can be molded from other plastics such as
polypropylene (PP) or polyethylene triphthalate (PET). It has been found
that HDPE provides economic savings in that a container of desired
thickness with sufficient strength can be formed. Referring to Figure 1,
container 10 has a top or neck 12 which is of circular cross-section, see
Figure 3. The neck 12 has a wide mouth of a diameter of at least 50 mm.
Diameters of at least 60 mm are also useful and, in particular, diameters of
from 70-100 mm or more are contemplated. The neck 12 can be sealed by
a cap 14 and be configured so as to allow the continuous opening and
closing of the cap 14 onto top 12 to dispense and effectively seal the
contents within the interior of container 10. Snap-on tops are useful.
Shown in Figure 1 is a twist top in which spiral threads 16 on neck 12
match with threads contained with the interior of cap 14. As shown, the
threads 16 include a circumferential thread 18, known as a security strip,
which ensures that the cap 14 remains secure on neck 12, even in the
event that container 10 is vigorously jostled or dropped.
From neck or top 12, container 10 contains a shoulder 20 which is of
a greater diameter than neck 12. Shoulder 20 preferably has a circular
cross-section throughout. However, other cross-section configurations are
possible ranging from elliptical to rectangular and square. By maintaining a
circular cross-section, it is believed the container of this invention fits
more
readily into known paint can handling equipment.
In the configuration of shoulder 20 as shown in Figure 1, shoulder 20
expands slightly from neck 12. Other configurations of the shoulder can be
provided as shown in the container of Figure 4. Below shoulder 20 is the
cylindrical body 22 of container 10. The body 22 has a uniform outer wall
and, again, is preferably of a circular cross-section substantially
throughout.
As above said regarding shoulder 20, body 22 may be provided with other
than a circular cross-section, although such other configurations are not
preferred. Positioned between shoulder 20 and body 22 is a
circumferential gripping ring 24 in the form of a circumferential indention
around container 10. The gripping ring has an outside diameter less than
both the outside diameters of shoulder 20 and body 22, and allows the user
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to hold the container within their hand, typically between the thumb and
forefinger. The container 10 does not contain any handle accessory which
needs to be separately molded or separately formed and subsequently
added to the container. Further, the container 10 of the present invention
does not include any handle configuration that extends or protrudes
laterally from the container. Thus, the mold for container 10 is of relatively
simple construction and allows for relatively easy molding with a uniform
thickness easy to obtain. The narrow diameter gripping ring 24 maintains
the preferred circular cross-section of the container 10 of this invention
from top to bottom, and allows the container 10 of this invention to be
utilized in conventional paint can handling and shaking equipment. To
strengthen container 10, the gripping ring 24 contains a plurality of vertical
ribs 26 circumferentially spaced along and molded into gripping ring 24.
The ribs 26 can be protrusions from the outer surface as shown or can be
indentions as shown in the container illustrated in Figure 5. The ribs 26
reinforce the strength of container 10 and, in particular, provide the
strength
necessary to withstand the vigorous shaking which takes place in
conventional paint mixing equipment.
Figure 4 illustrates another example of a plastic container within the
scope of the present invention and which is very similar to container 10 as
shown in Figure 1. As shown in Figure 4, the plastic container which is
generally indicated by reference numeral 30, and typically in a quart or one-
half gallon size, is formed by extrusion blow molding from the plastic
materials as used to form container 10 and described previously.
Container 30 contains a neck 32, which is preferably of a circular cross-
section. Neck 32 has a mouth of the same diameter as discussed with
respect to container 10. Neck 32 can be sealed by a cap, which is not
shown, and can be configured so as to allow the continuous opening and
closing of a cap onto the neck 32 to dispense and effectively seal the
contents within the interior of container 30. While snap-on tops can be
used as, shown in Figure 4, neck 32 contains spiral threads 34, which
would match the threads contained in the interior of a cap. Neck 32 also
includes a circumferential thread 36, known as a security strip equivalent to
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security strip 18, as shown in Figure 1. The security strip ensures that any
cap that is enclosed around neck 32 remains secure in place in the event
that the container 30 is vigorously shaken or dropped.
From neck 32, container 30 contains a shoulder 38 that is of a
greater diameter than neck 32. Shoulder 38 preferably has a circular
cross-section throughout. A particular difference between container 30 and
container 10 of Figure 1 is the shape of the shoulder 38. Thus, the
shoulder 38 is of a rounded or vertical shape as compared to shoulder 20
of container 10, in which the shoulder expands slightly from the neck. The
exact outer shape of the shoulder 38 is not of particular criticality to the
present invention.
Below shoulder 38 is a cylindrical body 40 of container 30. Body 40
has a uniform outer wall and, again, is preferably of a circular cross-section
substantially throughout. Body 40 may be provided with other than a
circular cross-section, although such other configurations are not preferred.
Positioned between shoulder 38 and body 40 is a circumferential gripping
ring 42 in the form of a circumferential indention around container 30. The
gripping ring has an outside diameter less than both the outside diameters
of shoulder 38 and body 40, and is equivalent to the gripping ring 24 of
container 10, shown in Figure 1. The gripping ring allows the user to hold
the container in one hand, typically between the thumb and the forefinger,
and wherein the shoulder 38 abuts the top of the hand surface. Like
container 10, container 30 does not contain any handle accessory which
needs to be separately molded or separately formed and subsequently
attached to the container. Further, container 30 does not include any
handle configuration that extends or protrudes laterally from the container.
Such shape allows for the mold of container 30 to be of a simple
construction. Moreover, the shape of the container allows it to be readily
placed into conventional paint mixing equipment and shaken vigorously
without disrupting any lateral handle configurations.
Container 30 also contains a series of circumferentially spaced ribs
44 molded into the gripping ring 42. As shown in Figure 4, the ribs 44 are
protrusions from the outer surface of container 30, but can be indentions in
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which the ribs would extend from the inward surface of the container. The
ribs 44 greatly strengthen the plastic container 30 and allow the plastic
container to be vigorously shaken in paint mixing equipment without
destruction of the container structure.
In Figure 5 is shown still another alternative plastic container within
the scope of the present invention. In Figure 5, the plastic container is
generally indicated by reference numeral 50, and can be formed of the
same plastic materials such as high-density polyethylene, polypropylene,
and polyethylene terephthalate, as previously described. Again, container
50 can be formed by any known molding technique, although extrusion
blow molding would be a particularly useful method of forming the
container. Container 50 contains a neck 52, which can be sealed by a cap
not shown by means of threads 54 placed on the neck 52, and which would
match threads that would be contained in the inside of any cap. A security
strip 56 is also shown, and would allow the twist-on cap to be secured to
.the neck 52 and container 50, in the event that container 50 is vigorously
shaken, such as in the paint mixing equipment as known, or accidentally
dropped. The hand gripping portion of container, 50 indicated by reference
numeral 58, is not formed by a circumferential indented ring, as in
containers 10 and 30. Importantly, however, the hand grip portion 58 of
container 50 contains a plurality of circumferentially-spaced ribs 60, which
greatly increase the strength of the plastic container and allow it to be used
in the conventional paint mixing equipment, and still maintain the integrity
of the container during the vigorous shaking in such equipment. The ribs
60, as shown in Figure 5, are indentions, or in other words, protrude from
the interior surface of the container. It is understood that the ribs 60 can
be
in the form of the indentions as shown or protrusions from the outer surface
as shown by ribs 26 and 44 in Figures 1 and 4, respectively.
Below the hand grip portion 58 is a body portion 62. The body 62
generally has a uniform outer wall and is preferably of a circular cross-
section substantially throughout. Likewise, the hand grip portion 60 and the
neck 52 are all preferably of a circular cross-section. The gripping portion
58 of container 50 can expand from neck 52 to body portion 62, although
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the exact configuration of the gripping portion 58 is not particularly
critical.
What is most useful is that the plastic container is provided with a series of
the spaced ribs 60 to provide the necessary strength for the plastic
container to withstand the vigorous forces that are placed on the container
5 during the paint mixing step.
EXAMPLE 1
In this example, the pouring speeds of colorant from plastic
containers of this invention in quart and '/2 gallon sizes were compared to
10 that of the typically used quart metal cans.
POUR TEST
Container % Material Pour Time to Pour Time
Left in Can Thin Stream to Dri
Quart Can (2 holes 3.9-4.2 15-20 sec -35 sec
with church key)
Quart Can (no lid 3.1 -5 sec -20 sec
New Quart (no lid) 3.3-3.6 -5 sec 20-25 sec
After Scraping Out:
2.2-2.4
New'/2 Gal (no lid)2 2.1-2.6 <10 sec 35-70 sec
After Scraping Out:
1.7-2.2
1. 4 inch diameter opening
2. 89 mm (3.5 inch) diameter opening
Due to the larger opening than the two holes from a church key can
opener pour times were reduced 65-75% (10-15 seconds) per container
with the quart container of this invention. The larger opening allows
additional material to be recovered using a rubber kitchen spatula. Wasted
material is significantly reduced using the '/2 gallon container when
compared to two of the existing quart cans. Residual colorant was reduced
by an average of 1.7%. With roughly 60 seconds of scraping, an additional
0.4% could be recovered. Pour time for the '/2 gallon container was less
than 10 seconds to empty the container to a thin stream. Pour times on an
equivalent basis for two quart cans were up to four times longer (40
seconds, not including time for opening the can versus 10 seconds for the
'/2 gallon).
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Without scraping, a yield improvement of 1.7% on the high volume
colorants in the '/2 gallon containers equates to hundreds of thousands of
dollars in annual savings realized by the customer. Savings in employee
costs are also realized from faster pour times on the quart container using
a 10 second per container reduction in pour time and from the faster pour
times on the 1/2 gallon container (10 seconds vs. 35 seconds) per container.
