Note: Descriptions are shown in the official language in which they were submitted.
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HOT-FILLABLE CONTAINER AND METHOD FOR
BOTTLING A BEVERAGE
Technical Field
[0001] The present invention relates to blow-moulded plastic
containers, and more particularly to containers designed to be filled with
a beverage by a "hot-fill" method.
Background
[0002] Many beverages are packaged in blow-moulded plastic
containers, and in particular, in polyethylene terephthalate (PET)
bottles. While some beverages are packaged by aseptic means or
utilizing preservatives, many other beverages - fruit juices and isotonic
drinks, for example - are "hot-filled" . Hot-filling involves the filling of
a container with a liquid beverage having some elevated temperature
(typically, at about 180 - 200°F) . The container is capped and allowed
to cool, producing a vacuum therein.
[0003] Hot-filling provides various advantages over aseptic or
preservative packaging, among them lower capital and operational cost
(over aseptic systems), and the elimination of the need for preservatives
(the heat of the beverage has a sanitizing effect). The hot headspace in
the filled bottle also reduces the carrying capacity of oxygen therein,
limiting oxidation of the contents.
[0004] Hot-fillable PET bottles have been well-known for many
years, and a variety of such bottles are available today in the market.
There are various requirements for such bottles. Most importantly, they
must be able to provide thermal resistance against the hot-filled con-
tents. They should also provide an ultraviolet (UV) light barrier and an
oxygen (and in some cases a carbon dioxide) barrier to protect the
contents from degradation. Their third requirement is that they must be
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constructed so as to be able to withstand the vacuum created in the
bottle as the contents cools, to maintain their intended shape.
[0005] The first two of these requirements are met by manufactur-
ing bottles out of suitable materials, such as PET, and various combina-
tions of such materials. In some instances, the plastics used to produce
such bottles may be layered. In other instances, certain additives may
be blended directly into the initial resins to provide certain qualitites
such as UV resistance.
[0006] The third of these requirements is typically met by con-
structing the bottles with certain stiffening structures known in the art as
"heat panels", "collapse panels" or "vacuum panels" which typically
form a portion of the sides of the bottles. Essentially, these panels,
which are described in a variety of patents such as United States Patent
No's. 5,762,221 and 6,375,025, which are incorporated herein by
reference, prevent the bottle from collapsing in on itself when the
vacuum is generated therein by the cooling of the hot-filled contents.
[0007] However, these stiffening structures adversely affect, in the
view of some, the aesthetic look of a bottle, because they prevent the
bottle from assuming a traditional round, or cylindrical shape, as a glass
bottle would have. Studies have indicated that the configuration and
overall aesthetic appearance of a beverage bottle can significantly affect
consumer purchasing decisions. A bottle which appears dented or
distorted is not necessarily appreciated by consumers, although many
manufacturers try to rationalize these distortions as providing "gripping"
surfaces for the bottles. Moreover, the panels prevent a label from
neatly encircling the circumference of the bottle, since the side of the
bottle is not smooth.
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[0008] There remains a need, therefore, for a hot-fillable PET
bottle with smooth sides and lacking heat panels.
Summar3r of Invention
[0009] The present invention provides an improved hot-fillable
bottle, and an improved method for hot-filling a bottle, using the im-
proved bottle.
[0010] More particularly, the improved bottle is made from a pre-
form having a certain mass per volume size of the desired bottle, which
allows the bottle to be constructed without stiffening structures, and
with smooth sides. Specifically, there is described herein a hot-fillable
beverage container, comprising a circular base portion; a shoulder
portion; a neck portion extending upwardly from the shoulder portion;
and a cylindrical body portion extending between the base portion and
the shoulder portion. The cylindrical body portion has a circular
transverse cross-section along its entire length, and lacks distinct panels
formed thereon. The container is constructed from a pre-form of plastic
material having a mass, PF",~5, as a function of the desired volume of the
container, in litres, calculated according to the following function:
97g/1 < PFm~ < 135g/1.
[0011] In a preferred embodiment, the pre-form has a mass of:
109g/1 < PFm~B < 118g/1.
[0012] In a preferred embodiment the pre-form is made of PET. In
another embodiment, the pre-form is a combination of PET and polyeth-
ylene naphthalate (PEN).
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[0013] The hot-fillable bottle may have a dimple formed in the
base portion thereof which extends into the interior of the bottle, the
dimple having a plurality of indicia surrounding its edge, indicating one
or more compass points, thereby allowing the bottle to be used as a
compass in combination with a thin length of metal.
[0014] In a preferred embodiment of the invention, the neck
portion of the bottle has threads, and the bottle has a cap threadable onto
the neck portion, the cap having a lower portion having threads for
threading the cap onto the neck portion of the bottle, and an upper
portion defining a hole therethrough for removably attaching the bottle
to an attachment location, for example, onto a back-pack.
[0015] There is also provided, in a known method for hot-filling a
bottle, the method comprising the steps of filling a bottle with a heated
beverage, capping the bottle, and allowing the bottle and its contents to
cool, an improvement which comprises providing a bottle having the
characteristics of this new hot-fillable bottle.
Brief Description of Drawings
[0016] Figure 1 is a perspective view of a hot-fillable bottle made
in accordance with one embodiment of the invention;
[0017] Figure 2 is a side view of the bottle shown in Figure 1;
[0018] Figure 3 is a bottom view of the bottle shown in Figure 1;
and
[0019] Figure 4 is a perspective view of a preferred cap for the
bottle shown in Figure 1.
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Description
[0020] Throughout the following description, specific details are
set forth in order to provide a more thorough understanding of the
invention. However, the invention may be practised without these
particulars. In other instances, well known elements have not been
shown or described in detail to avoid unnecessarily obscuring the
invention. Accordingly, the specification and drawings are to be re-
garded in an illustrative, rather than a restrictive, sense.
[0021] Referring first to Figure 1, a hot-finable container or bottle,
denoted " 10" throughout this description, has a base portion 12, a
shoulder portion 16, and a neck portion 18 sitting atop the shoulder
portion 16, in the manner of many traditional bottles.
[0022] The base portion 12 is preferably circular when viewed
from the bottom of the bottle, as shown in Figure 3, as is the shoulder
portion 16 and the neck portion 18, when viewed from the top of the
bottle 10. A cylindrical body portion 14 of the bottle 10 extends be-
tween the top of base portion 12 and the bottom of shoulder portion 16.
Bottle 10 may be constructed of any suitable plastic material, but in a
preferred embodiment is constructed of polyethylene terephthalate
(PET), as described below. In another embodiment, bottle 10 is con-
structed of a combination of PET and polyethylene naphthalate (PEN) .
Any other suitable plastic material may be employed.
[0023] As described earlier, many hot-fillable bottles are made of
a plastic material such as PET. This allows the production of light-
weight bottles which do not break as readily as glass bottles. Such
bottles are made from a process known in the art as injection or stretch
blow-moulding. In this process, a "pre-form" amount of plastic, again,
usually PET, having an neck portion, an interior portion and an exterior
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portion, is placed into a mould in a heated state. Air or another gas is
injected into the interior portion of the pre-form, through the neck
portion, forcing the pre-form to expand to the limits of the mould to
assume the desired bottle shape. The newly-formed bottle begins to
cool within the mould, and is released from the mould to continue to
cool.
[0024] Due to cost considerations, bottle manufacturers attempt to
limit as much as possible the amount of PET in the bottle (and originally
in the pre-form). Limiting the amount of PET which is used to form the
bottle may make the bottles too thin, however, to be able withstand the
vacuum created within the bottle during the hot-filling process. Hence,
manufacturers have been developing stiffening structures for hot-filled
bottles as described earlier.
[0025] Although it might be suggested that increasing the amount
of plastic in the bottle might increase its strength, thereby avoiding the
need for such stiffening structures, there are number of factors which,
to date, have prevented manufacturers from successfully making bottles
with an increased amount of PET.
[01126] First, most manufacturers attempt to limit the plastic in a
bottle to save cost. The focus of bottle manufacturers is thus on meth-
ods of reducing the amount of plastic used to make a bottle. Further,
from a manufacturing point of view, if too much plastic is used in the
production of a PET bottle, the bottle will collapse under its own weight
when it is removed from the mould during the manufacturing process.
Also, the bottle will not cool properly if too much plastic is used.
[0027] The present inventors have discovered the fine line which
exists between having too little plastic in a bottle (forcing the require-
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ment for stiffening structures and their attendant problems), and having
too much plastic in a bottle (with the limitations discussed above). This
line may be more clearly defined by way of the following formula:
97g/1 < PF"~$ < 135g/1
wherein PF",~S is the mass (in grams) of the plastic pre-form which
should be used to make a hot-fillable PET bottle which will not require
stiffening structures, per desired volume of the bottle, in litres. In a
preferred embodiment, this range may be more narrowly defined in
accordance with the following function:
109g/1 < PFmass < 118g/1.
[0028] In a preferred embodiment of the bottle, for example, a
bottle having a volume of 620 ml (21 oz.) may be produced using a pre-
form having a mass of between approximately 68g and 73g. A typical
hot-fill bottle requiring heat panels has, by way of contrast, a mass of
about 35g, or only about half of the mass of the present bottle.
[0029] The inventors have found that using this amount of plastic
in the production of a hot-fillable bottle allows the bottle 10 to be
moulded with the body portion 14 thereof having a circular transverse
cross-section along its entire length, without the need for any distinct
panels formed along its length. This allows bottle 10 to present a
pleasing, rounded shape to the consumer, and also allows a label 35
(Figure 2) to be applied to bottle 10, label 35 showing a smooth face
without dimpling.
[0030] The inventors have also determined that using this amount
of PET will also provide bottle 10 with enough thickness in body
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portion 14 to provide an appropriate UV barrier without the requirement
for extra, UV-blocking layers of plastic. A bottle produced in accor-
dance with the present invention will also provide an appropriate oxygen
barrier. In practise, it has been determined that a bottle produced in
accordance with the present invention has a typical thickness of between
approximately 0.025" and 0.055". By contrast, a typical hot-fillable
bottle employing heat panels has a thickness of approximately 0.008" -
0.020" . The relative thickness of the bottle also conveniently provides
the bottle with better insulative properties - beverages tend to warm up
less slowly in the present bottle than in known PET bottles.
[0031] In a preferred embodiment, the present bottle 10 also has a
dimple 30 formed in base portion 12, extending into the interior of
bottle 10. It will be appreciated that dimple 30 may strengthen bottle
10, but one of its purposes is to allow bottle 10 to be used as a compass
in combination with a thin length of metal, such as a pin. In particular,
dimple 30 may be provided with a plurality of indicia SOa, SOb sur-
rounding its edge, indicating one or more compass points. When bottle
10 is inverted, and dimple 30 filled with a liquid, a pin may be placed
on top of this liquid and, as is well known, the pin will tend to indicate
magnetic North. The bottle user turns the bottle so as to align the
"North" indicia with the pin, and thereby may gain a sense of direction.
[0032] Bottle 10 may of course be capped with any suitable cap,
but it being foreseen that bottle 10 will be reusable (given its strength),
bottle 10 may be provided with a specialized cap 40 (shown in Figure
4), which allows bottle 10 to be removably attached to an attachment
point (for example, onto a back pack, not shown). Cap 40 has a lower
portion 42 having inner threads for threading cap 40 onto neck portion
18 of bottle 10, and an upper portion defining a hole 44 therethrough for
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removably attaching bottle 10 to an attachment location with any suit-
able attachment means (for example, a carabineer) .
[0033] Bottle 10 may, as is known in the art, be moulded with
various trade-marks and other indicia 20a, 20b.
[0034] The new bottle may be produced by an improved method.
In a known method, a hot-fillable bottle is produced by the steps of
providing a pre-form of PET material having as little mass as possible to
provide a one-time use container, and injecting a gas into the pre-form,
thereby expanding it within a mould to a desired size and shape. The
improved step involves the provision of a PET pre-form having a mass,
PF",~5, calculated as a function of the desired volume of the bottle, in
litres, according to the following function:
109g/1 < PFm~S < 118g/1,
which allows the production of a bottle which can be reused many
times.
[0035] This improved bottle 10 may be used in a known method
for hot-filling a bottle, the method having the steps of filling bottle 10
with a heated beverage, capping the bottle with cap 40, and allowing the
bottle and its contents to cool.
[0036] As will be apparent to those skilled in the art in the light of
the foregoing disclosure, many alterations and modifications are possi-
ble in the practice of this invention without departing from the spirit or
scope thereof. Accordingly, the scope of the invention is to be con-
strued in accordance with the substance defined by the following claims.
