U.S. patent application number 12/281439 was filed with the patent office on 2009-02-12 for drinking straw with integral filters.
This patent application is currently assigned to Unistraw Patent Holdings Limited. Invention is credited to Peter Baron.
Application Number | 20090041904 12/281439 |
Document ID | / |
Family ID | 38458594 |
Filed Date | 2009-02-12 |
United States Patent
Application |
20090041904 |
Kind Code |
A1 |
Baron; Peter |
February 12, 2009 |
DRINKING STRAW WITH INTEGRAL FILTERS
Abstract
A drinking straw (1) for progressively adding an active
ingredient to a carrier liquid as the liquid is drawn through the
straw. The straw (1) includes a generally elongate tubular body (2)
having an internal bore (3) and a sidewall (4). The tube (2)
includes first and second filters (5) and (6) disposed at
respective first and second ends (7) and (8), of the tube.
Together, the first and second filters retain a predetermined
measure of soluble active ingredients within the bore of the tube
(2), while allowing a carrier liquid to be drawn through the straw,
by oral suction. The active ingredient, takes the form of a
plurality of solid pellets (9). Each filter is formed by blocking,
closing or constricting the tube at or adjacent the corresponding
end and providing at least one aperture sized to be sufficiently
small to retain the pellets within the tube whilst sufficiently
large to allow passage of liquid.
Inventors: |
Baron; Peter; (New South
Wales, AU) |
Correspondence
Address: |
BANNER & WITCOFF, LTD.
1100 13th STREET, N.W., SUITE 1200
WASHINGTON
DC
20005-4051
US
|
Assignee: |
Unistraw Patent Holdings
Limited
Federal Territory of Labuan
MY
|
Family ID: |
38458594 |
Appl. No.: |
12/281439 |
Filed: |
March 2, 2007 |
PCT Filed: |
March 2, 2007 |
PCT NO: |
PCT/AU2007/000265 |
371 Date: |
September 2, 2008 |
Current U.S.
Class: |
426/85 ;
426/394 |
Current CPC
Class: |
B31F 1/0083 20130101;
A47G 21/183 20130101; Y10T 137/0402 20150401 |
Class at
Publication: |
426/85 ;
426/394 |
International
Class: |
A47G 21/18 20060101
A47G021/18 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 2, 2006 |
AU |
2006901056 |
Claims
1. A method of manufacturing a drinking straw adapted progressively
to add an active ingredient to a carrier liquid drawn through the
straw, said method including the steps of: providing a generally
elongate tube having a sidewall defining an internal bore and first
and second open ends; providing a first filtration means adjacent
the first end of the tube; depositing a plurality of pellets
containing a measure of soluble active ingredient into the tube
through the second end; and providing second filtration means
adjacent the second end of the tube, wherein said first and second
filtration means retain the pellets substantially within the tube
whilst allowing the carrier liquid to be drawn through the tube by
oral suction and wherein at least one of said filtration means is
provided by forming the sidewall adjacent the respective end of the
tube into filtration means.
2. A method according to claim 1 wherein the step of forming the
filtration means includes: at least partially blocking the
respective open end; and providing a perforated section at the
respective end including at least one aperture sized to be
sufficiently small to retain the pellets within the tube and
sufficiently large to allow passage of liquid through the straw in
response to oral suction.
3. A method according to claim 1 wherein the steps of providing
first and second filtration means includes the steps of: at least
partially blocking the respective open end; and providing a
perforated section at the respective end including at least one
aperture sized to be sufficiently small to retain the pellets
within the tube and sufficiently large to allow passage of liquid
through the straw in response to oral suction.
4. A method according to claim 2 wherein an open end of the tube is
at least partially blocked by clamping opposing sides of the tube
adjacent said end and bonding the opposing sides together.
5. A method according to claim 4 wherein, bonding the sidewall
forms a seam extending generally across the tube.
6. A method according to claim 5 wherein, the seam is substantially
crescent shaped and extends partially down opposing sides of the
tube.
7. A method according to claim 5 wherein, the seam defines the end
of the tube, and is shaped by trimming so as to remove sharp
corners.
8. A method according to claim 5 wherein, bonding is achieved by
means of thermoplastic welding.
9. A method according to any claim 2 wherein the perforated section
includes a plurality of said apertures.
10. A method according to claim 9 wherein the apertures are formed
in a regular array.
11. A method according to claim 9 wherein the apertures are formed
on opposing sides of the tube.
12. A method according to claim 2 wherein the apertures are
slots.
13. A method according to claim 2 wherein the perforated section is
formed by punching the external sidewall of the tube.
14. A method according to claim 2 wherein the perforated section is
formed by piercing the external sidewall of the tube.
15. A method according to claim 1 including the step of clipping
the end of the tube to remove sharp corners.
16. A drinking straw adapted progressively to add an active
ingredient to a carrier liquid drawn through the straw, said straw
being manufactured in accordance with the method defined of any one
of the preceding claims.
17. A drinking straw adapted progressively to add an active
ingredient to a carrier liquid drawn through the straw, said straw
including: a generally elongate tube having a sidewall defining an
internal bore and first and second open ends; a plurality of
pellets containing a measure of soluble active ingredient; first
filtration means formed from the sidewall adjacent the first end to
retain the pellets substantially within the tube while allowing the
carrier liquid to be drawn through the tube by oral suction; and
second filtration means adjacent the first end to retain the
pellets substantially within the tube while allowing the carrier
liquid to be drawn through the tube by oral suction.
18. A drinking straw according to claim 17 wherein the second
filtration means is formed from the sidewall adjacent the second
end.
19. A drinking straw according to claim 17 wherein, each filtration
means includes at least one respective aperture sized to be
sufficiently small to retain the pellets within the tube and
sufficiently large to allow passage of liquid.
20. A drinking straw according to claim 19 wherein, the first
filtration means includes a lateral seam wherein opposing sides of
the sidewall are bonded together, thereby to close the first open
end and wherein at least one aperture is formed in the sidewall
adjacent the seam.
21. A drinking straw according to claim 20 wherein the first
sidewall is bonded together by thermoplastic welding.
22. A drinking straw according to claim 20 wherein the first
filtration means includes a perforated section having plurality of
apertures sized to be sufficiently small to retain the pellets
within the tube and sufficiently large to allow passage of liquid
through the straw in response to oral suction.
23. A drinking straw according to claim 20 wherein, the seam
defines the end of the tube, and includes a rounded profile.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to a method and
apparatus for the addition of soluble agents or ingredients to a
carrier liquid, at the point of consumption, for oral
administration through a straw.
[0002] The invention has been developed primarily for use in
relation to the flavouring of pre-packaged or bottled beverages
such as milk, and will be described with reference to this
application. It will be appreciated, however, that the invention is
not limited to this particular use and may be also used to provide
flavouring or colouring to other beverages, or for the oral
administration of soluble nutritional, pharmaceutical, health or
energy enhancing agents.
BACKGROUND OF THE INVENTION
[0003] The following discussion of the prior art is provided as
technical background, to enable the features and benefits of the
invention to be fully appreciated in an appropriate technical
context. However, any reference to the prior art should not be
taken as an express or implied admission that such art is widely
known or forms part of common general knowledge in the field.
[0004] It is known in the art to use soluble pellets or granules,
retained by perforated end caps within an elongate tubular body in
the form of a straw, to progressively disperse flavouring agents or
other ingredients into a carrier liquid drawn through the straw by
oral suction, at the point of consumption. Application WO 98/15187
discloses one such device. However, such straws may be
unnecessarily complicated and too costly to produce, particularly
in disposable form.
[0005] It is an object of the present invention to overcome or
substantially ameliorate one or more of the limitations of the
prior art, or at least to provide a useful alternative.
DISCLOSURE OF THE INVENTION
[0006] Accordingly, in a first aspect, the invention provides a
method of manufacturing a drinking straw adapted progressively to
add an active ingredient to a carrier liquid drawn through the
straw, said method including the steps of:
[0007] providing a generally elongate tube having a sidewall
defining an internal bore and first and second open ends;
[0008] providing a first filtration means adjacent the first end of
the tube;
[0009] depositing a plurality of pellets containing a measure of
soluble active ingredient into the tube through the second end;
and
[0010] providing second filtration means adjacent the second end of
the tube,
[0011] wherein said first and second filtration means retain the
pellets substantially within the tube whilst allowing the carrier
liquid to be drawn through the tube by oral suction and wherein at
least one of said filtration means is provided by forming the to
sidewall adjacent the respective end of the tube into filtration
means.
[0012] The terms "dissolved", "soluble" and the like as used herein
are intended to be construed sufficiently broadly to encompass not
only dissolution in the strict chemical sense, but also suspensions
and mixtures with the carrier liquid.
[0013] It will be appreciated that the steps presented above may
not necessarily be performed in the order recited. Furthermore, the
terminology "first end" and "second end" are entirely arbitrary and
applied merely to differentiate the ends of the straw rather than
an order of steps performed.
[0014] Preferably the tube is generally circular in
cross-section.
[0015] Preferably, the method includes forming the sidewall
adjacent both ends of the straw into filtration means.
[0016] Preferably, the step of forming each of the respective open
ends into filtration means includes the further steps of at least
partially blocking the respective end, and forming perforations in
the blocked end.
[0017] More preferably, each open end of the tube is blocked by
clamping opposing sides of the tube adjacent to the end, and
bonding the sides together. Preferably, the bond step forms a seam
extending generally across the tube. Preferably, each bond is
formed by means of thermoplastic welding.
[0018] Preferably, each seam is substantially crescent shaped and
extends partially down the corresponding side of the tube.
Preferably, the seam defines the respective ends of the tube, which
are shaped by trimming or rounding so as to remove any sharp
corners.
[0019] Preferably, the perforations at each end of the tube are
formed in sections, and each section includes a plurality of
apertures sized to be sufficiently small to retain the pellets
within the tube and sufficiently large to allow passage of liquid
through the straw in response to oral suction. More preferably, the
apertures take the form of elongate slots formed on opposing sides
of the tube.
[0020] Preferably, the perforated sections are formed by punching
the sidewalls of the tube.
[0021] Preferably the pellets are of a predetermined size and
shape. Preferably the pellets contain a predetermined measure of
soluble active ingredient.
[0022] In another aspect, the invention provides a drinking straw
adapted progressively to add an active ingredient to a carrier
liquid drawn through the straw, said straw including:
[0023] a generally elongate tube having a sidewall defining an
internal bore and first and second open ends;
[0024] a plurality of pellets containing a measure of soluble
active ingredient;
[0025] first filtration means formed from the sidewall adjacent the
first end to retain the pellets substantially within the tube while
allowing the carrier liquid to be drawn through the tube by oral
suction; and
[0026] second filtration means adjacent the first end to retain the
pellets substantially within the tube while allowing the carrier
liquid to be drawn through the tube by oral suction.
[0027] Preferably, each filtration means includes at least one
aperture sized to be sufficiently small to retain the pellets
within the tube and sufficiently large to allow relatively
unimpeded passage of liquid.
[0028] Preferably, each filtration means includes a blockage or
closure of the tube at or adjacent the respective end. The blockage
or closure is preferably formed by opposing sides of the tube being
pinched and bonded together.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Preferred embodiments of the invention will now be
described, by way of example only, with reference to the
accompanying drawings in which:
[0030] FIG. 1 is a perspective view of a drinking straw containing
soluble active ingredients in accordance with the invention;
[0031] FIG. 2A is a perspective view of another embodiment of the
drinking straw having a concertina section, in accordance with the
invention;
[0032] FIG. 2B is a perspective view of the drinking straw shown in
FIG. 2A, in a bent configuration;
[0033] FIG. 3A is a pictorial view of a tube used to form the straw
in accordance with the invention;
[0034] FIGS. 3B and 3C are pictorial views of the tube showing the
concertina section being formed therein;
[0035] FIG. 3D is a pictorial view depicting the formation of a
first filter at a first end of the tube;
[0036] FIG. 3E is a pictorial view showing the active ingredient
being added inside the tube;
[0037] FIG. 3F is a pictorial view showing the formation of a
second filter at the second end of the straw;
[0038] FIG. 4 is an enlarged view showing the end of the tube
incorporating a simple transverse weld in accordance with the
invention;
[0039] FIG. 5 is an enlarged view of the end of the straw shown in
FIG. 1;
[0040] FIGS. 6 and 7 are enlarged views of the ends of alternative
embodiments of the straw in accordance with the invention; and
[0041] FIGS. 8 to 12 are enlarged views of the end of a tube in
accordance with alternative embodiments of the invention.
PREFERRED EMBODIMENT OF THE INVENTION
[0042] Referring to the drawings, the invention provides a drinking
straw 1 for progressively adding an active ingredient to a carrier
liquid as the liquid is drawn through the straw. It will be
appreciated that FIGS. 1, 2A and 2B show the straw as being of
indefinite length.
[0043] Typically, the carrier liquid is a plain beverage such as
milk or water, and the active ingredient is a flavouring and/or
colouring agent. It should be appreciated, however, that other
active ingredients, such as pharmaceuticals, vitamin and mineral
supplements, antioxidants, herbal remedies or probiotics, and other
carrier liquids, may additionally or alternatively be used.
[0044] As can be seen in FIG. 1, the straw 1 includes a generally
elongate tubular body 2 having an internal bore 3 and a sidewall 4,
adapted for use as a straw. The tube 2 includes first and second
filters 5 and 6 disposed at respective first and second ends 7 and
8, of the tube. Together, the first and second filters retain a
predetermined measure of soluble active ingredients within the bore
of the tube 2, while allowing a carrier liquid to be drawn through
the straw, by oral suction. The active ingredient, preferably a
flavouring agent, takes the form of a plurality of solid pellets 9.
Although generally spherical, in some forms the pellets may be
slightly elongated or cylindrical.
[0045] The filters 5 and 6 are formed integrally from the
respective ends of the tube and as such do not require any
additional parts or components. More specifically, each filter is
formed by blocking, closing or constricting the tube at or adjacent
the corresponding end and providing at least one aperture sized to
be sufficiently small to retain the pellets within the tube whilst
sufficiently large to allow passage of liquid.
[0046] In the preferred embodiment, each open end of the tube is
blocked by pinching it flat, so that the opposing sides are brought
together. Once in contact, the sides are bonded together, thereby
effectively closing the end of the tube. The aperture takes the
form of a perforated section 10 of the tube. Each perforated
section 10 includes a plurality of apertures 11 disposed in an
array on each side of the tube.
[0047] The invention also extends to a method of manufacturing the
drinking straw. In very general terms, the method includes steps of
forming a tube of a predetermined length and size, forming a first
end of the tube into the first filter; depositing the predetermined
amount of active ingredient in the form of pellets within the tube;
and forming the other, second end of the tube into the second
filter, so as to encapsulate the pellets within the tube. It will
be appreciated that in the embodiment of the invention as
illustrated, the perforations may be formed either before or after
the pellets are added. A concertina section in the tube may also be
provided.
[0048] A more detailed description of one particular embodiment of
the straw and its preferred method of manufacture follow.
[0049] As shown in FIG. 3A, the tube used to form the straw is a
cylindrical extrusion, ideally of a food-grade thermosetting
plastic. Preferably, the tube has a substantially circular cross
section although other extrusion sections may be used, for instance
oval, ellipsoid or polygon sections. Furthermore, the plastic is
transparent or partially transparent, to allow the user to visually
monitor the inside of the straw. In this embodiment, polypropylene
is used because it is non-toxic, may be readily heat welded and is
available in transparent forms. It will be appreciated, however,
that in place of polypropylene, any other form of plastics
material, or any other suitable material such as waxed paper, metal
foils or the like may be used to form the straw.
[0050] In this embodiment, the circular extrusion has an inside
diameter of around 5.5 mm and outside diameter of around 6.0 mm,
with a wall thickness of around 0.25 mm. The extrusion is cut into
lengths of around 200 mm. However, it will be appreciated that the
invention is not limited to a straw of these particular dimensions.
For instance, in an alternative, larger version, the extrusion has
an inside diameter of 10 mm and outside diameter of 11 mm, with a
wall thickness of 0.5 mm and a straw has a length of 20 mm.
[0051] Referring to FIGS. 3B and 3C, the first stage of
transforming the tube into the drinking straw is to form the
concertina section 12 in the tube sidewall. The concertina section
12 includes an array of circumferential ribs 13 formed in a
saw-tooth profile, which allow the straw to be extended or bent
whilst maintaining continuity of the internal bore.
[0052] It will be appreciated that formation of the concertina
section is entirely optional. Its inclusion allows bending of the
straw to provide adjustment of the inclination of the mouth end of
the straw for ergonomic drinking. In addition, it provides the
straw with the ability to be bent back over 90.degree. to shorten
its overall length. This is advantageous in one application, where
the straw is packaged on the side of a container of fixed
dimensions, because it allows for packaging of a straw longer than
the container. However, this advantage along with methods of
forming the concertina section are well known in the art.
[0053] Next, as shown in FIG. 3D, the first end 7 of the tube 2 is
formed into the first filter 5 in a three-stage procedure. The end
7 of the tube is clamped flat and the tube sidewalls are bonded
together by heat welding of the thermosetting plastic sidewall. The
perforated sections are formed by punching or piercing apertures in
the sidewalls of the tube, toward the corresponding end. The end of
the straw is then trimmed or otherwise smoothed around the weld to
shape the straw and eliminate any sharp corners or protrusions that
could potentially cause oral discomfort to the user. These three
steps may be performed substantially simultaneously, or in almost
any order. For instance, it is possible to first clamp the tube,
punch the holes and trim the corners, before bonding the sides
together.
[0054] In a simple form, as shown in FIG. 4, weld 14 is
substantially straight, extending transversely across the end of
the tube in a direction normal to the longitudinal tube axis.
Blocking the tube in this way provides an advantage when the straw
is used with carrier liquids packaged in the type of cartons which
include a frangible membrane, positioned and sized on the carton to
be pierced by, and subsequently to accommodate, a correspondingly
sized drinking straw. Conventional straws used in this context are
obliquely cut, so as to provide a sharpened end adapted to
facilitate piercing of the carton membrane. However, in place of
the sharpened end, the present invention provides the straw with an
end having a bonded double layer of sidewall material. This double
layer forms a relatively stiff edge 15, well adapted for piercing
the carton's frangible membrane.
[0055] As can be seen in FIG. 4, pinching the tube and welding in
this way results in an increase in width of the tube at the end to
approximately .pi./2 times the width, or around 50%, of the
original diameter. The increase in width can be seen as both an
advantage and a disadvantage. On the one hand, the increased width
may result in the end of the straw being too wide to easily fit and
pass through the circular aperture surrounding the carton membrane,
which is usually sized and shaped according to the nominal diameter
of the straw. On the other hand, provided the wider end fits within
the confines of the frangible area, the wider end may provide an
advantage since it tends to open a pair of slit extensions on
either side of the hole formed by the straw piercing the frangible
membrane. These slits provide breathing holes to allow air to enter
the carton as fluid is removed.
[0056] In addition, pinching and welding the end of the tube
results in the formation of relatively sharp corners 16 and 17
which may cause discomfort when placed in the mouth of the
user.
[0057] For this reason, in the embodiment of the invention shown in
FIG. 5, the corners 16 and 17 are trimmed off and rounded to
eliminate sharp corners and reduce the width of the end of the
tube. The degree of trimming is selected to balance the requirement
for a reduced straw width with the above mentioned advantage of
breathing hole formation.
[0058] As a further variation, as shown in FIG. 5, rather than
extending directly across the straw, the weld 18 may be formed in
an inverted-U or crescent shape, extending partially along the
outer edges of the straw, parallel to the longitudinal axis. The
crescent-shaped weld 18 seals the edges of the straw which may
otherwise be open as a result of the corners being trimmed, and in
addition, provides enhanced stability and structural integrity for
the straw end, which is advantageous when piercing the frangible
carton membrane.
[0059] Of course the welding and clipping of the ends of the tube
is not limited to the shapes shown in FIGS. 4 and 5. Alternative
shapes are shown in FIGS. 6 and 7, which provide the same
advantages as the straw shown in FIG. 5, but with pointed or
rounded ends 19 and 20 respectively, to further assist in piercing
the carton membrane.
[0060] Several other alternatives or additions may also be applied.
For instance, a variety of methods, other than heat welding, may be
used for bonding the sidewalls of the tube together including the
use of adhesives, plastic welding, ultrasonic welding, or any other
suitable method.
[0061] In addition, rather than pinching and welding, alternative
methods of closing the end of the tube may be used. For instance,
the tube may be blocked by crushing, crimping, folding, by slitting
the end of the tube to create a number of flaps and then folding
the flaps together, or any other suitable method or
combination.
[0062] A selection of some possible alternative methods for sealing
the end of the tube are shown in FIGS. 8 to 12.
[0063] In FIG. 8, the tube end is pinched and welded together on
four rather than two sides. This forms a star shaped end 21 which
may be trimmed to remove sharp corners.
[0064] In FIG. 9 four circumferentially spaced, longitudinal slits
22 are made in the end of the tube. These slits divide the tube end
into four flaps 23 which may be folded inwardly and sealed
together, thereby closing or partially closing the opening and
giving the end of the tube a square profile.
[0065] A similar approach has been taken in the embodiment shown in
FIG. 10. Here, a plurality of slits 24 are used to divide the tube
end into a plurality of flaps 25 that are folded inwardly. While
more complex, this provides a more circular profile to the end of
the tube than that of the embodiment shown in FIG. 9.
[0066] In FIG. 11, an array of V-shaped notches 26 have be cut in
the end of the tube. The notches divide the tube end into
triangular flaps 27 that are folded inwards to meet along adjacent
respective edges.
[0067] In FIG. 12 the end of the tube is heated and crimped
inwardly to form a rounded or domed tube end 28.
[0068] In still other embodiments, the ends of the tube are not
completely blocked but are constricted. That is, the ends are only
partially closed, such that one or more apertures remain in the end
of the straw. This may be accomplished by providing a seal or weld
that does not extend fully, or is discontinuous, across the straw.
For instance it will be noticed that a central aperture 29 remains
in the embodiments shown in FIGS. 10 to 12. Either way, any
apertures of openings resulting from partial constriction of the
ends of the tube are sized and shaped to retain the pellets within
the straw whilst allowing relative unimpeded passage of liquid.
These constriction type apertures may provide the only fluid
passages through the respective filters, or be used in addition to,
and in conjunction with, the apertures formed in the sidewall of
the tube by piercing, perforation or other means, as previously
described. In this regard, the apertures 11 which form the
perforated sections 10 may be circular holes, as shown in the
figures, or any other suitable shape including any combination of
holes, slits or slots. It will be appreciated that the shape and
size of the holes will be dictated to a large degree by the shape
and size of the pellets.
[0069] For instance, one advantage of providing elongate slots in
conjunction with spherical pellets is that the dissimilarity in
shape tends to prevent the pellets from blocking or clogging the
slotted apertures as they dissolve. Rather, when the pellets
dissolve to a predetermined suitably small diameter, they are able
to pass through the slotted apertures and out of the straw, to be
safely ingested by the consumer. This tends to reduce the
possibility of blocking of the filters and accordingly, fluid flow
is maintained at all times, while premature consumption of coarse
flavouring particles is also avoided. The apertures may be placed
in discrete arrays on either side of the tube, as depicted in the
drawings, or in any other regular or irregular arrangement at or
adjacent the end of the tube.
[0070] In this embodiments the invention as illustrated, the
apertures are punched through both sidewalls of the straw whilst it
is clamped, with a male punch and a corresponding female die. This
operation may be performed along with the trimming and bonding
operations. Alternatively, the apertures may be formed by piercing
the sidewalls with a lance. The lance may be heated to melt the
plastic sidewall.
[0071] Returning to FIG. 3E, once the first filter 5 of the straw
is formed at the first end of the tube 7, the pellets 9 are added.
The tube 2 is held in a generally upright orientation, so that the
first filer is positioned below the open end 8 of the tube. The
pellets may be added to the tube via this top open end. Filling may
be vacuum assisted.
[0072] The predetermined volume of pellets 9 contained within the
tube is calculated to be sufficient for the volume of beverage with
which the straw is intended to be sold or used. This particular
straw has been configured to be used with relatively smaller
volumes of liquid than those shown for instance in WO 98/15187.
However, as previously noted, in alternative embodiments, the straw
may be manufactured in larger or even smaller sizes, with
corresponding volumes of active ingredient as required. In cases
where pharmaceuticals or vitamin supplements are included, the
volume of pellets used will be dictated by the concentration of the
active ingredient, and the required dosage.
[0073] Once a predetermined amount of pellets has been added to the
tube, the second end 8 of the tube is formed into the second filter
6. This may be accomplished in the same manner as described above
in relation to the formation of the first filter 5.
[0074] In other embodiments, the filter in each end of the straw
may be formed differently. For instance, only one end of the tube
may be formed into an integral filter, while the filter at the
other end of the straw may be formed by the addition of a discrete
filter element, such as that described in WO 98/15187.
[0075] The concentration of active ingredient in the liquid exiting
the straw is dependant upon: the size; shape and number of pellets
used in the straw; the "dwell time" within the straw; the
concentration of active ingredient in the pellets and the effective
dissolution rate of each pellet as well as external influences such
as; temperature; humidity and carrier liquid properties,
composition and viscosity.
[0076] In terms of controllable properties, the spherical shape
pellet is advantageous because it not only provides a predicable
and steady rate of dissolution, it also enhances the flow
characteristics of the pellets in bulk form in order to facilitate
filling of the straw during production. Furthermore, the spherical
shape is resistant to crushing and fragmentation thereby reducing
the amount of powder in the straw, which may prematurely dissolve
or be ingested by the user.
[0077] In some cases, however, spherical pellets may be costly to
manufacture and accordingly, in alternative embodiments, the
pellets may be non-spherical, for example elongate, prolate
spheroid, cylindrical or in tablet or capsule form. For instance in
a particular embodiment, the pellets are formed by extrusion
resulting in pellets having a generally regular prism or
cylindrical shape whether the cross section be circular, oval or
otherwise.
[0078] The size of the pellets not only alters surface area but
also affects the dwell time of the liquid within the straw. Large
pellets will provide looser packing giving larger spaces between
the pellets and a more direct route for liquid passing through the
straw. Accordingly, larger pellets generally result in a reduced
dwell time and increased flow rate for a given suction pressure.
However, if the pellets are made too large with respect to the
internal diameter of the straw, they can block the passage
substantially or completely, or provide in adequate surface
area.
[0079] Accordingly, the pellets are sized so as to be complementary
with respect to the width and shape of the straw cross-section.
Generally, given a circular straw and spherical pellets, the
pellets have a diameter between 10% and around 80%, more preferably
between 15% and 70%, and most preferably between 20% and around 50%
of the internal diameter of the straw but ideally no larger than
half the internal diameter. It has been found through painstaking
development and testing that with this combination, the pellets
have appropriate combined surface area to ensure adequate flavour
infusion, and are retained until substantially dissolved, yet do
not result in clogging of the filters. It will be appreciated, that
under real world conditions, the formation of perfectly spherical
pellets are unlikely. In such cases the above dimensions are given
as a guide to be interpreted within the bounds of the art.
[0080] In the case of non-spherical pellets and tubes previously
disclosed, appropriate selection of the size of the pellets in
relation to the tube diameter should be applied. However, as a
general rule when close packed, the ratio of volume of pellets to
volume of interstitial void should be no more than 4.5 to 1 and
preferably less than 3.5 to 1 and more preferably less than 3 to
1.
[0081] Two other important factors effecting the concentration of
active ingredient in the carrier liquid exiting the straw are the
concentration of the active ingredient within the pellets and the
dissolution rate of the pellet itself. A highly concentrated pellet
will impart a higher concentration of active ingredient to the
carrier liquid. Similarly, a pellet, which dissolves more readily,
will also provide a higher exit concentration of active ingredient,
all other variables being equal. In this respect, the straw is
intended to be a disposable, single use item. The dissolution rate
of the pellets is selected to match a particular volume of milk or
other beverage, such that once that prescribed volume has passed
through the straw, the pellets will have dissolved completely or to
such an extent that they are small enough to pass through the
apertures in the filters and exit the straw. At this stage, the
transparent wall of the straw will allow the user to identify that
the straw is devoid of pellets and is ready to be discarded. In one
particular embodiment, the spherical pellets of the invention are
ideally in the form of "nonpareil" balls, which enables close
control of the above variables in comparison to other shapes and
methods of manufacture.
[0082] Nonpareil balls are formed by building up a plurality of
layers on a "seed". Typically, this seed will be a sugar crystal.
However, any other suitable nuclei may be used. Nonpareil pellet
formation allows the size of the pellet to be controlled and
ensures that shape is generally spherical. Furthermore, the
composition of the pellet can be adjusted layer by layer. Layers of
active ingredients including flavouring, sweetener or sugar,
colouring, starch and pharmaceuticals and vitamins and minerals can
be alternated in any order, as required.
[0083] This enables active ingredient concentration, and
dissolution rate to be varied throughout the cross section of the
ball. For instance, by providing a pellet with a high concentration
of flavouring toward the centre, a relatively uniform infusion rate
can be achieved, even as the pellet progressively reduces in size
and its surface area is diminished.
[0084] Furthermore, by way of example, flavours may also be mixed
or changed so that one flavour is added to the beverage initially,
and is subsequently replaced by another flavour as the pellets
dissolve. The change in flavour may be accompanied by a change in
colouring of the pellets and the user may identify this change
through the transparent or translucent side wall of the straw.
Artificial sweetener may also be used to sweeten the beverage or
carrier liquid as it passes through the straw. It will also be
appreciated that by providing a mixture of pellets of different
composition, a multitude of flavours or other active ingredients
can be infused simultaneously, rather than sequentially.
[0085] While, the straw of the invention may be packaged and sold
as individual items or in multiple packs, it is also envisaged that
the straw be sold along with a carton, container or bottle of
beverage such as milk, or mineral water. The straw, initially
packaged within a surrounding hygienically sealed disposable
wrapper (not shown) is affixed to the outside of the carton, in the
same manner used with conventional straws. This method conveniently
packages the straw and beverage together. The user detaches the
straw at the point of consumption, removes it from the wrapper and
uses one of the ends to pierce the frangible membrane on the
carton. The straw is then inserted into the carton through the
resultant opening, and the beverage may then be consumed through
the straw.
[0086] It will be appreciated that a particular embodiment of the
invention has been developed in order to add flavouring to drinks
such as milk, soy milk, mineral and carbonated waters, sodas, soft
drinks, milkshakes, cordials, juices, alcoholic beverages, and the
like, however the invention may equally be applied to add
sweeteners, vitamin supplements, nutritional, herbal,
pharmaceutical, health and energy additives to liquids for
ingestion. In such cases, the transparent sidewalls of the straw
are particularly advantageous for assessing that the correct dosage
of the agent has been administered. This may be indicated by an
empty straw or, as an encouragement to potentially reluctant
children, a visible colour or discernible flavour change in the
pellets.
[0087] Advantageously, the invention provides the user with a
degree of control over the intensity of the flavouring, according
to the rate at which the beverage is sucked through, and hence the
dwell time of the liquid within, the straw. It has also been found
that by only partially filling the straw with flavouring pellets,
the resultant free space provides for enhanced agitation of the
pellets and hence improved mixing. This in turn results in a more
uniform distribution of flavouring within the beverage as the
agitated pellets perform a stirring function.
[0088] Additionally, because the active ingredient is sealed in a
dry form, the product generally has a markedly superior shelf life
to products where the ingredient is contained in liquid form. For
instance, in the case of flavouring agents, the invention permits
the sale of a relatively inexpensive unflavoured beverage together
with an effective flavouring agent integrated with a straw, it is
envisaged that retailers will be able to achieve substantially
enhanced profit margins over the current form of sale of both
flavoured and unflavoured beverages, and particularly milk. The
consumer is provided with a greater variety of flavour selection,
optionally involving the combination of a number of different
flavours, and the possibility of applying the flavouring at any
desired concentration. Also, because the flavouring component of
the beverage will normally have a longer shelf life, particularly
in the case of milk, if any unused product needs to be discarded,
wastage of the flavouring component at least can be avoided.
Further, because the retailer can optionally stock a relatively
large number of plain beverages in the available refrigeration
space, with the flavouring receptacles stored elsewhere, stock and
inventory control can be greatly simplified.
[0089] Similar benefits apply to other active ingredients such as
pharmaceuticals and health and nutritional supplements.
[0090] The invention is also particularly advantageous in the
administration of soluble oral pharmaceuticals and other medical
treatments to young children and the elderly, who often have
difficulty swallowing such medicaments in conventional tablet or
capsule form.
[0091] Furthermore, it will be appreciated that the invention
provides a comparatively low cost method of producing a drinking
straw containing soluble agents in comparison to that described in
WO 98/15187. It achieves this advantage by eliminating the need to
assemble the straw from multiple components, each of which must be
manufactured separately, which is possible because the filtration
elements are formed integrally from the tubular body of the straw.
In these and other respects, the invention represents a practical
and commercially significant improvement over the prior art.
[0092] Although the invention has been described with reference to
specific examples, it will be appreciated by those skilled in the
art that the invention may be embodied in many other forms.
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