Note: Descriptions are shown in the official language in which they were submitted.
CA 02633117 2008-06-09
WO 2007/083142 PCT/GB2007/000183
MULTI-DOSING DETERGENT DELIVERY DEVICE
This invention relates to a multi-dosing detergent
delivery device containing a plurality of dosage elements
of cleaning composition, for use in a ware washing
machine, for example a dishwashing machine or a laundry
washing machine.
in multi-dosing detergent delivery devices it is
necessary to selectively feed a compartmentalized
cartridge with water and thereby provide a directed water
flow into a single compartment. This feeding system is
susceptible of clogging and needs to be free of blockages
for optimal water flow.
In European dishwashers a sophisticated water
filtering system is takes care of food soil and lumps
coming from soiled dishware. However, food soil can
still enter the system while the consumer is handling
soiled dishes when placing them in the rack of the
dishwasher and in some cases the filtering system of the
dishwasher is not efficient enough.
In dishwashers commonly in use in North America,
this issue is even more severe. The dishwasher filtering
system is generally much less efficient and therefore
food particles stay for prolonged times in the washing
liquor. The food particles are also pumped around in the
dishwasher and can reach the water feeding system of the
device. This leads in every second to third run to
complete blockage of the feeding system and as a result
to no or incomplete dissolution of the detergent in the
main wash cycle of the dishwasher.
CONFIRMATION COPY
CA 02633117 2008-06-09
WO 2007/083142 PCT/GB2007/000183
Attempting to solve the problems of ensuring proper
dissolution of the cleaning composition within a given
time frame in a dishwasher environment, is not 'a trivial
exercise as dishwasher design varies around the world,
and filtration systems in use in dishwashers show such
variation.
Accordingly, it is an aim of preferred embodiments
of the invention to provide a multi-dosing delivery
cartridge capable of overcoming, or minimising the above
mentioned problems and providing good resistance to
blockages regardless of dishwasher type or placement of
the device within any given dishwasher.
According to a first aspect of the invention, there
is provided a multi-dosing detergent delivery device
removably insertable into an automatic dishwashing
machine, the device comprising a cartridge capable of
receiving therein a rack of dosage elements of a cleaning
composition, a collection area formed in a lid area of
said device suitable to collect water/wash liquor in a
main wash cycle of a dishwasher, a directing means to
direct water or wash liquor from said collection area
selectively to an interior part of said device, wherein
the device further includes a sieve to prevent or impede
particles from blocking water/wash liquor flow into said
interior part of the device.
Preferably, said sieve is located in a lid area of
said device . and, most preferably, extends across
substantially a full available water collection area of
said lid.
2
CA 02633117 2008-06-09
WO 2007/083142 PCT/GB2007/000183
Preferably, said sieve comprises a non-hydrophobic
material.
Preferably, said sieve comprises a non-plastics
material.
Preferably, said sieve comprises a stainless steel
mesh.
Preferably, said mesh has a mesh size between 3.5mm
and 0.2mm, most preferably between imm and 0.4mm.
In a preferred embodiment, said sieve comprises
market grade, plain square weave, 304 stainless steel.
Said mesh may have a preferred aperture size of 0.4 to
0.42 mm and be made from wire having a diameter in the
range of 0.2 to 0.24.
Preferably, said device is a cylindrical device
having a diameter of approximatel.y 8cm.
Preferably each dosage e1ement is -of elongate
formation and is housed within a chamber having at least
one opening for receiving sieved water/wash liquor from
said directing means.
Preferably, the rack is in the form of a parallel
array of elongate chambers, each containing a solid
dosage element. Preferably, the nested form is generally
cylindrical for easy placement'within the device.
Preferably, each dosage element contains between 15
and 25g of cleaning composition.
3
CA 02633117 2008-06-09
WO 2007/083142 PCT/GB2007/000183
suitable material may be used, such as, cardboard-based
material (especially covered by a water-resistant
material). Laminated cardboard with a suitable laminate
is one material which rriay be used. Each sleeve may have
at least one opening to allow the dosage element to be
washed away in use. Preferably each sleeve has two
openings, at opposite ends so that water may enter one
end (the upper end in use) and leave the other end (the
lower end in use), carrying with it dissolved or broken
away cleaning composition. An upper opening may suitably
be of area at least 10 mm2, preferably at least 30 mm2,
and most preferably at least 60 mm2. Suitably it may be
of area up to 200 mm2, preferably up to 160 mm2, and most
preferably up to 120 mm2. The upper face of the sleeve
may suitably be left totally open. A lower opening may
suitably be of area at least 3 mm2, preferably at least 6
mm2, and, most preferably at least 10 mm2. Suitably it may
be of area up to 200 mm2, preferably up to 60 mm2 , and
most preferably up to 20 mm2. The lower face of the
sleeve is preferably not left totally open, so that it
retains the dosage element in place, until in use it
dissolves. There may be one or more intermediate
openings in the side face of the sleeve, i.e. between the
upper opening and the lower opening, and the size thereof
preferably conforms to the definitions given above for
the lower opening.
Preferably the sleeves are formed in one piece.
That piece may be in the form of a moulded or
thermoformed tray having multiple compartments, into
which the dosage elements are placed. The backing
material may be secured over the tray to entrap the
4
CA 02633117 2008-06-09
WO 2007/083142 PCT/GB2007/000183
Alternatively, the backing material may be on the inside
of the sleeves so that the dosage elements project
outwards therefrom e.g. a central core of backing
material with sleeves containing backing material
projecting radially putwards.
The dosage elements are of a solid cleaning
composition and as such may be of a particulate material,
for example powder or granules, provided that the
material is retained until it is washed away in use; for
example in a sleeve as described above. Preferably
however the dosage elements are of a solid cleaning
composition in the sense of being non-flowable.
Preferably they are of a coherent mass; preferably formed
by a moulding or shaping process, for example injection
moulding, extrusion, casting or compression forming. In
a particular embodiment of the invention the solid
cleaning composition may be a viscous gel or paste
provided that it is sufficiently viscous so as to be non-
flowable.
Preferably the dosage.elements are identical to each
other.
Preferably the dosage elements are of substantially
the same cross-section along their length; in particular,
they preferably do not taper.
Preferably the rack is such that, in its nested
form, each pair of dosage elements is separated by a
spacing, at least for part of the depth of the dosage
elements. The spacing preferably extends part-way
CA 02633117 2008-06-09
WO 2007/083142 PCT/GB2007/000183
cartridge into which the nested rack is placed, in use,
preferably has an array of walls radiating f rom a hub,
wherein spacings must be mated with divider walls when
the article is located in the device cartridge. There
could be one-to-one correspondence between spacings and
divider walls, but preferably there are more spacings
than divider walls. Three or four divider walls will
generally suffice to cause the nested rack to be located
correctly in the device cartridge. In general we may say
there are preferably 3-8 divider walls, preferably 4-6.
The multi-dosing detergent delivery device is
generally a plastics body, rigid and substantial, but the
nested rack, once the dosage elements have gone, is light
and may even be rather flimsy. It suitably comprises
just the backing material and the sleeves (which may be
light thermoformed sheet, or film). The rack is intended
as a refill, whilst the remainder of the multi-dosing
delivery device, comprising cartridge, collection area
and directing means, is retained. The wastage of
material when the rack of dosage elements is exhausted is
very small. The invention may, thus be seen as a
desirably ergonomic solution.
Preferably the device has means to deliver water to
the rack of dosage elements in sequence, one in'each
wash. Such means may operate automatically or be
operated by the user, before a wash is commenced.
The invention will now be further described, by way
of example, with reference to the accompanying drawings,
in which:
6
CA 02633117 2008-06-09
WO 2007/083142 PCT/GB2007/000183
Fig. 1 shows a rack of dosage elements for use with
a multi-dosing detergent delivery device of the present
invention in a nested form, in a perspective view,
generally from above;
Fig. 2 shows the article of Fig. 1 in ri.ested form,
in side view;
Fig. 3 shows the article of Fig. 1 in flat form;
Fig. 4 shows the dosage element of Fig. 3 in plan
view;
Fig. 5a shows the article of Fig. 1 being introduced
into a multi-dosing detergent delivery device of Fig. 5b,
the cap, containing the dosage element selecting device,
being shown removed, as Fig. 5c;
Fig. 6 shows the article of Fig. 1 having been
located within the holder of Fig. 5b; and
Fig. 7 shows the fully assembled device, with the
cap of Fig. 5c having been placed' on the holder and
article assembly of Fig. 6a.
The rack of dosage elements of Fig. 1 is
manufactured as a flat plastics tray of elongated blister
pockets 2, shown in Fig. 3, comprising' a thermoformed
plastics tray. The open end of each blister pocket 2 is
formed all around its perimeter with an endless flange 4
(which can be seen in=Fig. 2). Solid rods or sticks of a
cleaning composition 6 (intended in this embodiment to be
7
CA 02633117 2008-06-09
WO 2007/083142 PCT/GB2007/000183
different ways. For example in one embodiment the
cleaning composition can be injected or cast into the
pockets. However in this embodiment the rods or sticks
are pre-formed by injection moulding or extrusion, then
cut to length, then introduced into the pockets. It may
be noted that they are introduced into the pockets to
fill each pocket to the bottom end 8, but to leave a
space 10 at the top end. This space 10 is left so that
water can enter the pocket, via opening 12 in the upper
end wall of the pocket and, as is discussed later, may
a lso help in providing complete dissolution of cleaning
composition within a reduced time period. In this
embodiment each such opening 12 is circular, and 8mm in
diameter. An identical opening (not shown) is formed in
the lower end wall of the article, to allow water and
entrained or dissolved cleaning composition to exit the
pocket.
Once all of the pockets have been provided with the
rods or sticks of cleaning compositiori (by whatever
means) a backing sheet 14 is laid over the open ends, and
secured to the flanges,4. The backing may be adhered
thereto by any convenient means, for example by heat or
adhesive.
Next, the flat article, now in the form of a rack or
linear array of rods or sticks, may be curled into its
nested form shown in Fig. 1. In this embodiment the
nested form is a generally cylindrical array. It may be
retained in its nested form by a piece of adhesive tape
16.
8
CA 02633117 2008-06-09
WO 2007/083142 PCT/GB2007/000183
The backing may be printed on its outwards-facing
side with information, for example a trade mark, with
product get-up, and/or with usage information.
As shown in Fig. 4, each rod or stick - and
.correspondingly each blister, has a flat base wall 18
abutting the backing sheet 14. From the base wall 18,
each rod or stick, and each blister, generally tapers to
a narrower. distal end wall 20. The side walls initially
taper gradually, as at 22; 24, then undergo a somewhat
abrupt inward dislocation 26, then taper at an
intermediate rate (between that of the side wall portion
22 and the dislocation 26) at 27, until the distal end
wall 20 is reached.
The rods or sticks may be regarded as having the
general shape of a triangular prism (i.e. trigonal). To
be more precise, as noted above the side walls taper in a
discontinuous manner.
It will be noted that the rods or sticks are located
on the backing sheet with a separation 28 between them,
at their base walls 18.
It may further be noted that the rods or sticks have
a separation 30 between them, at their distal end region,
when in their nested form.
The backing sheet has, as a result of the mould into
which it is thermoformed during manufacture, preferential
fold lines 32., These fold lines 32 are aligned with the
spacings 28 between the rods or sticks.
9
CA 02633117 2008-06-09
WO 2007/083142 PCT/GB2007/000183
The end result of these features is as follows, and
can be clearly seen in Fig. 1: when the article is formed
into its nested shape the backing sheet is displaced
about its fold lines 22, in an articulated manner. This
nesting or folding is permitted by the spacings 28 and
30; if the sticks or rods simply abutted against each
other the operation would not be permitted, due to
physical obstruction. As can be seen in Fig. 1 the
spacings 30 in the distal end regions-may remain even in
the nested form (though obviously narrowed).
In use, the rack of dosage elements is a refill
which is supplied in~its nested form shown in Fig. 1, and
also Fig. 5a. In.that nested form it is inserted into a
holder, shown in Fig. 5b. The holder is a cylindrical
tub having a hub-like axial projection 40 extending
upwards from its base substantially the whole axial
length of the tub. Projecting outwardly from the
projection 40 are four fins 42, set at 90 intervals.
The fins extend approximately four-tenths of the radial
distance of the holder.
The holder has.a hanging handle 44.
The bottom wall of the holder is a large opening
(not shown).
The holder has a lid shown in Fig. 5c. The lid
defines a water/wash liquor collection area which extends
across substantially a full upper surface area of the lid
(in other- words, across substantially the full cross-
sectional area of the cylindrical device) and has a
CA 02633117 2008-06-09
WO 2007/083142 PCT/GB2007/000183
central indexing device has a push button 50 and, around
it, a dial 54 carrying numbers, equalling the number of
rods or sticks of cleaning composition. Each'time the
dishwasher is to be used, the user presses the button to
advance the control dial by one number, bringing the next
rod or stick of cleaning into use. This is done by
rotating an apertured disc within the lid by one position
so that water entering the holder is directed via
directing means comprising the aperture thereof, now in
alignment with- the next rod or stick. Water enters the
appropriate blister through the opening 12 which is
aligned with the opening within the lid. The water may
fill the spacing 10 above the rod or stick. The rod or
stick is soaked by the water and dissolves and/or
crumbles away, leaving the blister through the bottom
opening.
In cleaning performance tests -of the device a
specific number of soiled dishes with specific soils are
used. In the tests, it was found that there is a "bottle
neck" within the device that limits water flow, this
bottle-neck being equivalent to a constriction provided
by a hole having the dimensions of approximately 3 mm x 4
mm. In a tests featuring a North American design of
dishwasher in every second wash the bottle neck would, in
the absence of a sieving system become completely blocked
mainly by minced meat soil.
By including a sieve 48 within the device, the
following results were achieved.
Plastic sieves were initially used (made 'out of
Polypropylene or Polyethylene) however, these were
11
CA 02633117 2008-06-09
WO 2007/083142 PCT/GB2007/000183
large mesh sizes (4 mm in diameter or more) Such a
large size is required because plastics material has
hydrophobic features leading to air bubble formation and
a relatively high observed surface tension/contact angle
of the water on plastic which, on smaller meshes limits
water/wash liquor flow severely. Unfortunately however
whilst a large mesh size will allow sufficient clean
water flow, the mesh size is so large that it does not
provide any effective filtration to filter efficiently
soil from the washing liquor.
Surprisingly, metallic mesh sieves have been found
to be particularly effective. Stainless steel mesh
sieves with various mesh sizes have been tested. , Up to a
mesh-size of 0.3 mm aperture water can pass through.
Stainless steel sieves of a certain mesh size can
efficiently filter the washing liquor entering the device
and on the other hand do not reduce the water flow to an
unacceptable level (not more than 35 % reduction in water
flow) and, indeed, can help to remove the bottleneck from
the interior of the device and smooth overall flow.
Particularly preferred sieve meshes have been found
to be stainless steel sieves with a mesh size between 3.5
mm and 0.2 mm apertures , and most preferably between 0.4
to 1 mm aperture for the efficient filtering of food soil
without reducing the water flow significantly. In
preferred embodiments of the invention, the sieve
utilised is known as market grade, plain square weave,
304 stainless steel having a mesh size of 0.415mm and
made from 0.22mm diameter wire.
In devices in accordance with the invention,
12
CA 02633117 2008-06-09
WO 2007/083142 PCT/GB2007/000183
have been expected that dissolving dosage elements of the
cleaning composition by directing water to one end of
them in an axial or lengthwise direction might be an
inefficient method. In fact, dissolution or dispersion
is excellent and the arrangement is very space-efficient,
in not taking up very much of the "footprint area"
available within the dishwashing machine.
In determining the minimum footprint of the device,
a number of factors are involved. Firstly, it is
generally the case that for an efficient cleaning cycle
to be carried out by a dishwasher a dosage element should
contain between 15 and 25g of cleaning composition. For
efficient working within the device of the present
invention, an average density of the composition is set
within the range 'of 1.0 to 1.5g/cm3 and the preferred
hardness of the composition is between 100N-400N.
In arriving at required dimensions for the device,
dishwasher environments were analyzed for flow of
water/wash liquor and it was found that, in general,
water flow rates within a dishwasher are in the range of
ig of water to 15 g of water per square centimetre per
minute.
Tests have shown that standard dishwashing cleaning
compositions (detergents) show a complete dissolution
after 5 to 20 minutes in a standard dissolution test
comprising complete immersion of detergent in water, at
40 C, under mechanical action.
Where a cleaning composition having a 10 minute
13
CA 02633117 2008-06-09
WO 2007/083142 PCT/GB2007/000183
chamber, whereas for a 20 minute standard dissolution
time cleaning composition, a 500g per minute water flow
has been found to be required. Preferably the 'device of
the present invention utilises a cleaning composition
having a standard dissolution time of 5 minutes.
It has been found that a device which can collect
and direct by any means a minimum of 50g of water per
minute into a chamber is able to dissolve a cleaning
composition having a standard dissolution time of 5
minutes therein in a 50'C normal programme.
It is desirable for the device to function when
placed anywhere within a the dishwasher in which a.
minimum amount of water is available to it, and so it has
been assumed that perhaps only ig water per minute per
square cm is available. With this in mind, to assure
that said water collection area is sufficient to provide
50g of water per minute, a water collection area of 50cm2
is desirable, meaning'a cylindrical device will require a
diameter of approximately 8cm2. Whilst the foregoirig may
be the optimum dimensions for the device, it will be
appreciated that the present invention may be seen to
cover a range of devices with differing dimensions with,
for instance, water collection areas in the range of
30cm2 to 80cm2 and that where high flow rates of
water/wash liquor are known to be present a device, having
reduced dimensions may be utilised. Most preferably, the
ratio of said water collection area to cleaning
composition standard dissolution time is within the range
of 5 to 50 and, particularly in the range of 10 to 30.
14
CA 02633117 2008-06-09
WO 2007/083142 PCT/GB2007/000183
to be substantially completely disintegrated in a given
test environment. In such a test dosage elements are
provided in separate metal cages and mechanically
agitated in 4-0 C water. The dosage elements are, in
fact, not completely dissolved as such as they contain
some water insoluble ingredients, therefore we can not
speak about complete dissolution but "standard
dissolution" which equates here to complete
disintegration.
It has surprisingly been found that the dissolution
of cleaning composition within the device is aided when
each dosage element is housed within a chamber having a
larger volume than the cleaning composition stored within
it - hence the spacing 10 above the rod or stick - and it
may also be desirable to provide a spacing between a
lowermost part of the cleaning composition stick and the
bottom of its respective outer sleeve. Dissolution is
particularly improved when the volume of the chamber does
not exceed the volume of the dosage element by more than
40% and most preferably when the volume of the chamber
exceeds the volume of the dosage element by between 15
and 20%.
As can be seen in Fig. 6a, when the article is
located within the tub of the holder the fins 42 are
located within spacings 30 of the nested article. The
tolerance of the fins in the spacings 30 is not large and
in this way it is assured, that the rods or sticks, and
the upper openings 12, are in the correct orientation, to
align with the opening within the lid.
CA 02633117 2008-06-09
WO 2007/083142 PCT/GB2007/000183
As will be apparent to the skilled man, many
variations may be made to the device without departing
from the scope of the present invention. For instance,
whilst the sieve 48 is shown in figure 5(c) is located
within a central water collection area of the lid 46
surrounding the push button 50, it can be utilised
advantageously in different types of device, for instance
devices having automatic indexing systems driven by, for
instance a wax motor. In such cases, the mesh may
advantageously extend over a full top surface area of a
lid of the device.
16
