Note: Descriptions are shown in the official language in which they were submitted.
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IMPROVED CLEANING APPARATUS AND METHOD
Field of the Invention
[0001] The present invention relates to the aqueous cleaning of substrates
using a
cleaning system which requires the use of only limited quantities of energy,
water and
detergent. Most particularly, the invention is concerned with the cleaning of
textile fibres
and fabrics and other substrates by means of such a system, and provides an
apparatus
adapted for use in this context which provides significant design advantages
over the
systems of the prior art.
Background to the Invention
[0002] Aqueous cleaning processes are a mainstay of both domestic and
industrial
textile fabric washing. On the assumption that the desired level of cleaning
is achieved,
the efficacy of such processes is usually characterised by their levels of
consumption of
energy, water and detergent. In general, the lower the requirements with
regard to these
three components, the more efficient the washing process is deemed. The
downstream
effect of reduced water and detergent consumption is also significant, as this
minimises
the need for disposal of aqueous effluent, which is both extremely costly and
detrimental to
the environment.
[0003] Such washing processes involve aqueous submersion of fabrics followed
by soil
removal, aqueous soil suspension, and water rinsing. In general, within
practical limits, the
higher the level of energy (or temperature), water and detergent which is
used, the better
the cleaning. The key issue, however, concerns water consumption, as this sets
the
energy requirements (in order to heat the wash water), and the detergent
dosage (to
achieve the desired detergent concentration). In addition, the water usage
level defines
the mechanical action of the process on the fabric, which is another important
performance
parameter; this is the agitation of the cloth surface during washing, which
plays a key role
in releasing embedded soil. In aqueous processes, such mechanical action is
provided by
the water usage level in combination with the drum design for any particular
washing
machine. In general terms, it is found that the higher the water level in the
drum, the better
the mechanical action. Hence, there is a dichotomy created by the desire to
improve
overall process efficiency (i.e. reduce energy, water and detergent
consumption), and the
need for efficient mechanical action in the wash.
[0004] Various different approaches to the development of new cleaning
technologies
have been reported in the prior art, including methods which rely on
electrolytic cleaning or
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plasma cleaning, in addition to approaches which are based on ozone
technology,
ultrasonic technology or steam technology. Thus, for example, WO-A-2009/021919
teaches a fabric cleaning and disinfection process which utilises UV-produced
ozone along
with plasma. An alternative technology involves cold water washing in the
presence of
specified enzymes, whilst a further approach which is particularly favoured
relies on air-
wash technology and, for example, is disclosed in US-A-2009/0090138. In
addition,
various carbon dioxide cleaning technologies have been developed, such as the
methods
using ester additives and dense phase gas treatments which are described in US-
B-
7481893 and US-A-2008/0223406, although such methods generally find greater
applicability in the field of dry cleaning. Many of these technologies are,
however,
technically very complex.
[0005] In the light of the challenges which are associated with aqueous
washing
processes, the present inventors have previously devised a new approach to the
problem,
which is technologically straightforward, and yet still allows the
deficiencies demonstrated
by the methods of the prior art to be overcome. The method which is provided
eliminates
the requirement for the use of large volumes of water, but is still capable of
providing an
efficient means of cleaning and stain removal, whilst also yielding economic
and
environmental benefits.
[0006] Thus, in WO-A-2007/128962 there is disclosed a method and formulation
for
cleaning a soiled substrate, the method comprising the treatment of the
moistened
substrate with a formulation comprising a multiplicity of polymeric particles,
wherein the
formulation is free of organic solvents. Preferably, the substrate is wetted
so as to achieve
a substrate to water ratio of between 1:0.1 to 1:5 w/w, and optionally, the
formulation
additionally comprises at least one cleaning material, which typically
comprises a
surfactant, which most preferably has detergent properties. In preferred
embodiments, the
substrate comprises a textile fibre and the polymeric particles may, for
example, comprise
particles of polyamides, polyesters, polyalkenes, polyurethanes or their
copolymers, but
are most preferably in the form of nylon beads.
[0007] The use of this cleaning method, however, presents a requirement for
the
cleaning beads to be efficiently separated from the cleaned substrate at the
conclusion of
the cleaning operation, and this issue was initially addressed in WO-A-
2010/094959, which
provides a novel design of cleaning apparatus requiring the use of two
internal drums
capable of independent rotation, and which finds application in both
industrial and
domestic cleaning processes.
[0008] With a view to providing a simpler, more economical means for
addressing the
problem of efficient separation of the cleaning beads from the substrate at
the conclusion
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of the cleaning process, however, a further apparatus is disclosed in WO-A-
2011/064581.
The apparatus of WO-A-2011/064581, which finds application in both industrial
and
domestic cleaning processes, comprises a perforated drum and a removable outer
drum
skin which is adapted to prevent the ingress or egress of fluids and solid
particulate matter
from the interior of the drum. The cleaning method requires attachment of the
outer skin to
the drum during a first wash cycle, after which the skin is removed prior to
operating a
second wash cycle, following which the cleaned substrate is removed from the
drum.
[0009] The apparatus and method of WO-A-2011/064581 is found to be extremely
effective in successfully cleaning substrates, but the requirement for the
attachment and
removal of the outer skin detracts from the overall efficiency of the process
and the present
inventors have, therefore, sought to address this aspect of the cleaning
operation and to
provide a process wherein this procedural step is no longer necessary. Thus,
by providing
for continuous circulation of the cleaning beads during the cleaning process,
it has been
found possible to dispense with the requirement for the provision of an outer
skin.
[0010] Thus, in WO-A-2011/098815, the present inventors provided an apparatus
for use
in the cleaning of soiled substrates, the apparatus comprising housing means
having a first
upper chamber with a rotatably mounted cylindrical cage mounted therein and a
second
lower chamber located beneath the cylindrical cage, and additionally
comprising at least
one recirculation means, access means, pumping means and a multiplicity of
delivery
means, wherein the rotatably mounted cylindrical cage comprises a drum having
perforated side walls where up to 60% of the surface area of the side walls
comprises
perforations comprising holes having a diameter of no greater than 25.0 mm.
[0011] The apparatus is used for the cleaning of soiled substrates by means of
methods
which comprise the treatment of the substrates with formulations comprising
solid
particulate cleaning material and wash water, the methods typically comprising
the steps
of:
(a) introducing solid particulate cleaning material and water into the lower
chamber of the apparatus;
(b) agitating and heating the solid particulate cleaning material and water;
(c) loading at least one soiled substrate into the rotatably mounted
cylindrical
cage via the access means;
(d) closing the access means so as to provide a substantially sealed system;
(e) introducing the solid particulate cleaning material and water into the
rotatably
mounted cylindrical cage;
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(f) operating the apparatus for a wash cycle, wherein the rotatably mounted
cylindrical cage is caused to rotate and wherein fluids and solid particulate
cleaning material are caused to fall through perforations in the rotatably
mounted cylindrical cage into the lower chamber in a controlled manner;
(g) operating the pumping means so as to transfer fresh solid particulate
cleaning
material and recycle used solid particulate cleaning material to the
separating
means;
(h) operating control means so as to add the fresh and recycled solid
particulate
cleaning material to the rotatably mounted cylindrical cage in a controlled
manner; and
(i) continuing with steps (f), (g) and (h) as required to effect cleaning of
the soiled
substrate.
[0012] The requirement to introduce water and detergents into standard front
loading
washing machines has always presented a challenge to those in the industry,
but also
presents opportunities for increased efficiency of performance. Indeed, it
is well
understood that introducing water and detergency by spraying on to the load in
a front
loading washing machine provides both a means to generate cleaning
performance, and
also a way to reduce water consumption in the wash process. Subsequent
spraying of
rinse water is then a further means to reduce overall water consumption.
Typically, the
spray nozzle required to perform both functions is located at a point within
the machine
drum door that does not rotate with the movement of the wash drum, but the
spray
effectiveness of such an arrangement is typically limited.
[0013] Thus, in FR-A-2525645, for example, such a nozzle is fitted to the
centre of the
door of the machine, with the water spray therefore along the horizontal axis
of the wash
drum. This arrangement is somewhat inefficient, however, as it typically does
not fully wet
out the load in the drum as the items at the front prevent the spray from
reaching those
nearer the back, and those above the axis tend to receive less of the spray
than those
below the axis; the arrangement also inhibits easy opening and closing of the
door itself.
In order to address this latter problem, a flexible hose or a breakable
coupling can be used
in the water feed line, but neither option really offers a satisfactory
solution to the problem.
Routing the flexible hose in such a manner to still allow easy use of the
machine door is
difficult, and a breakable coupling is a potential source of leakage over time
as its seal
wears out with extended use.
[0014] In some alternative arrangements the spray nozzle is mounted at the
rear of the
drum, again on axis, or outside the drum surface, spraying through its
perforations. In
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such an arrangement, although the machine door is left unmodified, there is
either an
issue with inefficient wetting of the load from an on-axis spray to consider,
as with the
system of FR-A-2525645, or problems arise with wastage of water, as the spray
hits the
drum outer wall rather than passing through the perforations therein.
5 [0015] Such difficulties have to be addressed in the case of standard
washing operations
involving the use of detergents and water, but these problems are exacerbated
when using
solid particulate cleaning material (e.g. polymer beads) in the washing
process, and such
processes present similar, but much more demanding, problems in facilitating
the
transportation of beads into the drum.
[0016] In the case of the apparatus of WO-A-2011/098815, it is disclosed that
the access
means typically comprises a hinged door mounted in the casing, which may be
opened to
allow access to the inside of the cylindrical cage, and which may be closed in
order to
provide a substantially sealed system. The door typically includes a window
and at least
one addition port which facilitates the addition of materials to the rotatably
mounted
cylindrical cage. In operation, the solid particulate cleaning material is
added to the load in
the cylindrical cage via a feed tube mounted on the machine door (access
means).
[0017] Hence, this and other current washing machines using this type of bead
cleaning
technology, like conventional washing machines, also introduce cleaning
materials such as
beads through the machine door, and have, as a consequence, also been subject
to the
same problems associated with these conventional machines. Such an arrangement
is,
therefore, also not ideal and the present invention seeks to address this
issue by providing
alternative means for the introduction of these materials into the apparatus.
Summary of the Invention
[0018] Thus, according to a first aspect of the present invention, there is
provided an
apparatus for use in the cleaning of soiled substrates, said apparatus
comprising housing
means comprising:
(a) a stationary member;
(b) a rotatably mounted cylindrical cage; and
(c) access means,
wherein said stationary member comprises an annular planar member which is of
greater
internal diameter than said access means and is located adjacent said
rotatably mounted
cylindrical cage and said stationary member comprises a multiplicity of
delivery means
which are mounted thereon and a multiplicity of orifices which are
respectively operably
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connected to said multiplicity of delivery means, wherein said multiplicity of
delivery means
is adapted to facilitate the delivery of materials into said rotatably mounted
cylindrical cage.
[0019] In certain embodiments of the invention said rotatably mounted
cylindrical cage
comprises a drum comprising perforated side walls, wherein up to 60% of the
surface area
of said side walls comprises perforations, and said perforations comprise
holes having a
diameter of no greater than 25.0 mm.
[0020] In typical embodiments of the invention, no more than 50%, more
preferably no
more than 40%, of the side walls comprises perforations.
[0021] In embodiments of the invention, said perforations comprise holes
having a
diameter of from 2 to 25 mm, preferably from 4 to 10 mm, most preferably from
5 to 8 mm.
[0022] Said access means typically comprises at least one hinged door mounted
in the
housing means, which may be opened to allow access to the inside of the
cylindrical cage,
and which may be closed in order to provide a substantially sealed system.
Preferably, the
door includes a window.
[0023] The rotatably mounted cylindrical cage may be mounted about an
essentially
vertical axis within the housing means but, most preferably, is mounted about
an
essentially horizontal axis within said housing means.
Consequently, in preferred
embodiments of the invention, said access means is located in the front of the
apparatus,
providing a front-loading facility. When the rotatably mounted cylindrical
cage is vertically
mounted within the housing means, the access means is located in the top of
the
apparatus, providing a top-loading facility. However, for the purposes of the
further
description of the present invention, it will be assumed that said rotatably
mounted
cylindrical cage is mounted horizontally within said housing means.
[0024] Said rotatably mounted cylindrical cage is of the size which is to be
found in most
commercially available washing machines and tumble driers, and may have a
capacity in
the region of 10 to 7000 litres. A typical capacity for a domestic washing
machine would
be in the region of 30 to 120 litres whilst, for an industrial washer-
extractor, capacities
anywhere in the range of from 120 to 7000 litres are possible. A typical size
in this range
is that which is suitable for a 50 kg washload, wherein the drum has a volume
of 450 to
1150 litres, more typically 450 to 650 litres and, in such cases, said cage
would generally
comprise a cylinder with a diameter in the region of 75 to 120 cm, preferably
from 90 to
110 cm, and a length of between 40 and 100 cm, preferably between 60 and 90
cm.
Generally, the cage will have 10 litres of volume per kg of washload to be
cleaned.
[0025] Said stationary member is comprised in said housing means and typically
attached thereto by attachment means incorporating fixing members.
Necessarily, said
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stationary member is not fixedly attached to any moving components within said
apparatus
and, specifically, is located adjacent, but not fixedly attached to, said
rotatably mounted
cylindrical cage. Optionally, said stationary member may be intrinsically
comprised as part
of said housing means.
[0026] Said stationary member typically comprises a metallic member, most
frequently
formed of steel, which may, for example, be formed by pressing, machining, or
other
suitable fabrication processes. Optionally, said stationary member may
comprise a plastic
member, formed by moulding.
[0027] In typical embodiments of the invention, said rotatably mounted
cylindrical cage is
mounted in a first upper chamber of said housing means and said apparatus
additionally
comprises a second lower chamber located beneath said cylindrical cage.
Optimally, said
apparatus additionally comprises at least one recirculation means and/or
pumping means.
[0028] Thus, in a preferred embodiment, said apparatus according to the
present
invention, for use in the cleaning of soiled substrates, comprises housing
means
comprising:
(a) a first upper chamber having mounted therein a rotatably mounted
cylindrical cage and a stationary member;
(b) a second lower chamber located beneath said cylindrical cage;
(c) at least one recirculation means;
(d) access means;
(e) pumping means; and
(f) a multiplicity of delivery means,
wherein said stationary member comprises an annular planar member which is of
greater
internal diameter than said access means and is located adjacent said
rotatably mounted
cylindrical cage and said stationary member comprises a multiplicity of
delivery means
which are mounted thereon and a multiplicity of orifices which are
respectively operably
connected to said multiplicity of delivery means, wherein said multiplicity of
delivery means
is adapted to facilitate the delivery of materials into said rotatably mounted
cylindrical cage.
[0029] Rotation of said rotatably mounted cylindrical cage is effected by use
of drive
means, which typically comprises electrical drive means, in the form of an
electric motor.
Operation of said drive means is effected by control means which may be
programmed by
an operative.
[0030] Said apparatus is designed to operate in conjunction with soiled
substrates and
cleaning media comprising a solid particulate material, which is most
preferably in the form
of a multiplicity of polymeric particles. These polymeric particles are
required to be
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efficiently circulated to promote effective cleaning and the apparatus,
therefore, preferably
includes circulation means. Thus, the inner surface of the cylindrical side
walls of said
rotatably mounted cylindrical cage preferably comprises a multiplicity of
spaced apart
elongated protrusions affixed essentially perpendicularly to said inner
surface. Preferably,
said protrusions additionally comprise air amplifiers which are typically
driven
pneumatically and are adapted so as to promote circulation of a current of air
within said
cage. Typically said apparatus comprises from 3 to 10, most preferably 4, of
said
protrusions, which are commonly referred to as lifters.
[0031] In operation, agitation is provided by rotation of said rotatably
mounted cylindrical
cage. However, in preferred embodiments of the invention, there is also
provided
additional agitating means, in order to facilitate the efficient removal of
residual solid
particulate material at the conclusion of the cleaning operation. Preferably,
said agitating
means comprises an air jet.
[0032] Preferably, said rotatably mounted cylindrical cage is located within a
first upper
chamber of said housing means and beneath said first upper chamber is located
a second
lower chamber which functions as a collection chamber for said cleaning media.
Preferably, said lower chamber comprises an enlarged sump.
[0033] Said housing means includes standard plumbing features, thereby
providing at
least one recirculation means, in addition to said multiplicity of delivery
means attached to
said stationary member, by virtue of which at least water and, optionally,
cleaning agents
such as surfactants, in addition to said solid particulate cleaning material,
may initially be
introduced into the rotatably mounted cylindrical cage within said apparatus.
[0034] Said apparatus may additionally comprise means for circulating air
within said
housing means, and for adjusting the temperature and humidity therein. Said
means may
typically include, for example, a recirculating fan, an air heater, a water
atomiser and/or a
steam generator. Additionally, sensing means may also be provided for
determining, inter
alia, the temperature and humidity levels within the apparatus, and for
communicating this
information to the control means.
[0035] Said apparatus typically comprises at least one recirculation means,
thereby
facilitating recirculation of said solid particulate material from said lower
chamber to said
rotatably mounted cylindrical cage, for re-use in cleaning operations.
Preferably, said first
recirculation means comprises ducting connecting said second chamber and said
rotatably
mounted cylindrical cage. More preferably, said ducting comprises separating
means for
separating said solid particulate material from water, and diverting said
solid particulate
material into said cylindrical cage. Typically, said separating means
comprises a filter
material such as wire mesh located in a receptor vessel above said cylindrical
cage, said
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filter material being positioned, typically at a suitable predetermined angle,
so as to divert
the bead flow from said receptor vessel, via said multiplicity of delivery
means and said
stationary member, to the interior of the cylindrical cage.
[0036] Recirculation of solid particulate matter from said lower chamber to
said rotatably
mounted cylindrical cage is achieved by the use of pumping means comprised in
said first
recirculation means, wherein said pumping means is adapted to deliver said
solid
particulate matter to said separating means, which is adapted to control the
re-entry of said
solid particulate matter into said rotatably mounted cylindrical cage.
[0037] Preferably, said apparatus additionally includes a second recirculation
means,
allowing for the return of water separated by said separating means to said
lower chamber,
thereby facilitating re-use of said water in an environmentally beneficial
manner.
[0038] Preferably, said lower chamber comprises additional pumping means to
promote
circulation and mixing of the contents thereof, in addition to heating means,
allowing the
contents to be raised to a preferred temperature of operation.
[0039] In operation, during a typical cycle, soiled garments are first placed
into said
rotatably mounted cylindrical cage. Then, the solid particulate material and
the necessary
amount of water, together with any required additional cleaning agent, are
added to said
rotatably mounted cylindrical cage via the delivery means comprised in said
stationary
member. Optionally, said materials are heated to the desired temperature,
optionally in
the lower chamber comprised in the housing means and introduced, via the first
recirculation means, into the cylindrical cage. Alternatively, said cleaning
agent may, for
example, be pre-mixed with water prior to introduction into said cylindrical
cage via said
delivery means. Optionally, this water may be heated. Additional cleaning
agents, of
which bleach is a typical example, may be added with more, optionally heated,
water at
later stages during the wash cycle, using the same means.
[0040] During the course of agitation by rotation of the cage, the fluids and
a quantity of
the solid particulate material fall through the perforations in the cage and
into the lower
chamber of the apparatus. Thereafter, the solid particulate material may be re
circulated
via the first recirculation means such that it is transferred to said
separating means, from
which it is returned to the cylindrical cage for continuation of the washing
operation. This
process of continuous circulation of the solid particulate material carries on
throughout the
washing operation until cleaning is completed.
[0041] Thus, the solid particulate material which falls through the
perforations in the walls
of said rotatably mounted cylindrical cage and into said lower chamber is
carried to the top
side of said rotatably mounted cylindrical cage, wherein it is diverted from
said receptor
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vessel by said separation means and transported via said multiplicity of
delivery means
mounted on said stationary member back into said cage, thereby to continue the
cleaning
operation.
[0042] According to a second aspect of the present invention, there is
provided a method
5 for cleaning a soiled substrate, said method comprising the treatment of
the substrate with
a formulation comprising solid particulate cleaning material and wash water,
wherein said
method is carried out in an apparatus according to the first aspect of the
invention.
[0043] Preferably, said method comprises the steps of:
(a) introducing a solid particulate cleaning material and water into the
second
10 chamber of an apparatus according to the first aspect of the
invention;
(b) agitating and heating said solid particulate cleaning material and
water;
(c) loading at least one soiled substrate into said rotatably mounted
cylindrical
cage via access means;
(d) closing the access means so as to provide a substantially sealed
system;
(e) causing the rotatably mounted cylindrical cage to rotate whilst
introducing
said wash water and any required additional cleaning agent to uniformly wet
out the substrate;
(f) introducing said solid particulate cleaning material into said
rotatably
mounted cylindrical cage and operating the apparatus for a wash cycle,
wherein said rotatably mounted cylindrical cage continues to rotate, and
wherein fluids and solid particulate cleaning material are caused to fall
through perforations in said rotatably mounted cylindrical cage into said
second chamber in a controlled manner;
(g) operating pumping means so as to transfer fresh solid particulate
cleaning
material and recycle used solid particulate cleaning material to separating
means;
(h) adding said fresh and recycled solid particulate cleaning material to
said
rotatably mounted cylindrical cage in a controlled manner; and
continuing with steps (f), (g) and (h) as required to effect cleaning of the
soiled substrate.
[0044] Preferably, additional cleaning agents are employed in said method.
Said
additional cleaning agents may be added to the lower chamber of said apparatus
with said
solid particulate cleaning material, optionally heated to the desired
temperature therein and
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introduced, via the first recirculation means, into the cylindrical cage.
Preferably, however,
said additional cleaning agents are pre-mixed with water, which mixture may
optionally be
heated before addition to said cylindrical cage via said multiplicity of
delivery means
attached to said stationary member. Optionally, this addition may be carried
out using one
or more spray nozzles in order to better distribute said cleaning agents in
the washload.
[0045] Preferably, pumping of said fresh and recycled solid particulate
cleaning material
proceeds at a rate sufficient to maintain approximately the same level of
cleaning material
in said rotatably mounted cylindrical cage throughout the cleaning operation,
and to ensure
that the ratio of cleaning material to soiled substrate stays substantially
constant until the
wash cycle has been completed.
[0046] The generation of suitable G forces, in combination with the action of
the solid
particulate cleaning material, is a key factor in achieving an appropriate
level of cleaning of
the soiled substrate. G is a function of the cage size and the speed of
rotation of the cage
and, specifically, is the ratio of the centripetal force generated at the
inner surface of the
cage to the static weight of the washload. Thus, for a cage of inner radius r
(m), rotating at
R (rpm), with a washload of mass M (kg), and an instantaneous tangential
velocity of the
cage v (m/s), and taking g as the acceleration due to gravity at 9.81 m/s2:
Centripetal force = Mv2/r
Wash load static weight = Mg
v = 2-rrrR/60
Hence, G = 4u2r2R2/3600rg = 4Tr2rR2/3600g = 1.118 x 10-3rR2
[0047] When, as is usually the case, r is expressed in centimetres, rather
than metres,
then:
G = 1.118x 10-5rR2
Hence, for a drum of radius 49 cm rotating at 800 rpm, G = 350.6.
[0048] In a typical embodiment of the invention, a cylindrical drum having a
diameter of
98 cm is rotated at a speed of 30-800 rpm in order to generate G forces of
0.49-350.6 at
different stages during the cleaning process. In examples of alternative
embodiments of
the invention, a 48 cm diameter drum rotating at 1600 rpm can generate 687 G,
whilst a 60
cm diameter drum at the same speed of rotation generates 859 G.
[0049] In particular embodiments of the invention, the claimed method
additionally
provides for separation and recovery of the solid particulate cleaning
material, and this
may then be re-used in subsequent washes.
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[0050] During the wash cycle, rotation of said rotatably mounted cylindrical
cage is
preferably caused to occur at rotation speeds such that G is <1 which, for a
98 cm
diameter cage, requires a rotation speed of up to 42 rpm, with preferred rates
of rotation
being between 30 and 40 rpm.
[0051] On completion of the wash cycle, feeding of solid particulate cleaning
material into
the rotatably mounted cylindrical cage ceases and the speed of rotation of the
cage is
initially increased in order to effect a measure of drying of the cleaned
substrate, thereby
generating G forces of between 10 and 1000, more specifically between 40 and
400.
Typically, for a 98 cm diameter cage, rotation is at a speed of up to 800 rpm
in order to
achieve this effect. Subsequently, rotation speed is reduced and returned to
the speed of
the wash cycle so as to allow for removal of the solid particulate cleaning
material.
[0052] Optionally, following said bead removal operation, said method may
additionally
comprise a rinsing operation, wherein additional water may be added to said
rotatably
mounted cylindrical cage in order to effect complete removal of any additional
cleaning
agent employed in the cleaning operation. Water is added to said cylindrical
cage via said
multiplicity of delivery means attached to said stationary member. Again,
addition may
optionally be carried out by means of one or more spray nozzles in order to
achieve better
distribution of the rinsing water in the washload.
[0053] Alternatively, said addition may be made by overfilling the second,
lower chamber
of said apparatus with water such that it enters the first, upper chamber and
thereby
partially submerges said rotatably mounted cylindrical cage and enters into
said cage.
Following rotation at the same speed as during the wash cycle, water is
removed from said
cage by allowing the water level to fall as appropriate and the speed of
rotation of the cage
is then increased so as to achieve a measure of drying of the substrate.
Typically, for a 98
cm diameter cage, rotation is at a speed of up to 800 rpm in order to achieve
this effect.
Subsequently, rotation speed is reduced and returned to the speed of the wash
cycle,
thereby allowing for final removal of any remaining solid particulate cleaning
material. Said
rinsing and drying cycles may be repeated as often as desired.
[0054] Optionally, said rinse cycle may be used for the purposes of substrate
treatment,
involving the addition of treatment agents such as anti-redeposition
additives, optical
brighteners, perfumes, softeners and starch to the rinse water via said
multiplicity of
delivery means mounted on said stationary member.
[0055] Said solid particulate cleaning material is preferably subjected to a
cleaning
operation in said lower chamber by sluicing said chamber with clean water in
the presence
or absence of a cleaning agent, such as a surfactant. Optionally, this water
may be
heated. Alternatively, cleaning of the solid particulate cleaning material may
be achieved
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as a separate stage in said rotatably mounted cylindrical cage, again using
water which
may optionally be heated.
[0056] Generally, any remaining solid particulate cleaning material on said at
least one
substrate may be easily removed by shaking the at least one substrate. If
necessary,
however, further remaining solid particulate cleaning material may be removed
by suction
means, preferably comprising a vacuum wand.
Brief Description of the Drawings
[0057] The invention will now be further illustrated by reference to the
following
drawings, wherein:
Figures 1 and 2 both show an apparatus according to the invention, and
particularly
illustrate the deployment of the stationary member and the multiplicity of
delivery
means in the apparatus.
Detailed Description of the Invention
[0058] The present inventors have addressed the issues associated with the
introduction
of materials into cleaning apparatus via access means such as machine doors by
providing alternative means for the introduction of these materials into such
apparatus and,
as a consequence, have developed an apparatus for use in the cleaning of
soiled
substrates, said apparatus comprising housing means comprising:
(a) a stationary member;
(b) a rotatably mounted cylindrical cage; and
(c) access means,
wherein said stationary member comprises an annular planar member which is of
greater
internal diameter than said access means and is located adjacent said
rotatably mounted
cylindrical cage and said stationary member comprises a multiplicity of
delivery means
which are mounted thereon and a multiplicity of orifices which are
respectively operably
connected to said multiplicity of delivery means, wherein said multiplicity of
delivery means
is adapted to facilitate the delivery of materials into said rotatably mounted
cylindrical cage.
[0059] Said stationary member is comprised in said housing means and typically
attached thereto by attachment means incorporating fixing members.
Necessarily, said
stationary member is not fixedly attached to any moving components within said
apparatus
and, specifically, is located adjacent, but not fixedly attached to, said
rotatably mounted
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cylindrical cage. Optionally, said stationary member may be intrinsically
comprised as part
of said housing means.
[0060] Said stationary member typically comprises a metallic member, most
frequently
formed of steel, which may, for example, be formed by pressing, machining, or
other
suitable fabrication processes. Optionally, said stationary member may
comprise a plastic
member, formed by moulding.
[0061] In typical embodiments of the invention, said stationary member
comprises a flat,
annular ring piece of larger internal diameter than the access means, which is
typically a
door. The stationary member is located within the housing means, but is not
attached to
any rotating parts. This stationary member may be adapted to suit the
requirements of the
specific washing machine, i.e. the desired placement and shape of any inlets
for cleaning
materials, or water spray nozzles, within the housing means but outside the
perimeter of
the access means, or door.
[0062] Typically, the stationary member effectively replaces some of the inner
part of the
front of the rotatably mounted cylindrical cage and, as a consequence, it is
necessary that
the edges of said stationary member should be smoothed, in order to avoid
damage to the
soiled substrate in the load, particularly when this comprises textile
substrates.
Additionally, the gap around the circumference between the stationary member
and the
rotating cylindrical cage is required to be sufficiently small to prevent
trapping of the soiled
substrate. This gap may range from 1-25 mm, more often from 2-10 mm. More
typically,
however, it is found that a gap in the region of from 3-5 mm suffices for this
purpose. The
essential requirement in this regard is that water and solid particulate
cleaning materials
may suitably be added via the multiplicity of delivery means associated with
the stationary
member, through individual spray nozzles or particulate material inlets
respectively,
without constraining the operability, or reducing the size, of the access
means.
[0063] Thus, in a typical commercial washing apparatus, the stationary member
may
comprise a disc of metal, most frequently steel, which is formed by pressing,
machining, or
other suitable fabrication processes, and wherein the outer edges of the disc
are rolled to
prevent damage to the substrate which is being treated. Typical domestic
washing
machines frequently use plastic mouldings in the doors comprising their access
means
and, hence, the stationary member in such an arrangement could also be such a
moulding
with smoothed edges.
[0064] The apparatus according to the invention may conveniently be derived by
modification of the apparatus disclosed in WO-A-2011/098815.
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[0065] The apparatus according to the invention may be used for the cleaning
of any of a
wide range of substrates including, for example, plastics materials, leather,
paper,
cardboard, metal, glass or wood. In practice, however, said apparatus is
principally
designed for use in the cleaning of substrates comprising textile fibre
garments, and has
5 been shown to be particularly successful in achieving efficient cleaning
of textile fibres
which may, for example, comprise either natural fibres, such as cotton, or man-
made and
synthetic textile fibres, for example nylon 6,6, polyester, cellulose acetate,
or fibre blends
thereof.
[0066] The apparatus of the invention may be used for conventional aqueous
washing
10 processes as well as for the so-called bead-technology washing processes
which involve
the use of a solid particulate cleaning material. In such processes, the solid
particulate
cleaning material most preferably comprises a multiplicity of polymeric
particles. Typically,
the polymeric particles comprise polyalkenes such as polyethylene and
polypropylene,
polyamides, polyesters or polyurethanes, which may be foamed or unfoamed.
15 Furthermore, said polymers may be linear or crosslinked. Preferably,
however, said
polymeric particles comprise polyamide or polyester particles, most
particularly particles of
nylon, polyethylene terephthalate or polybutylene terephthalate, most
preferably in the
form of beads. Said polyamides and polyesters are found to be particularly
effective for
aqueous stain/soil removal, whilst polyalkenes are especially useful for the
removal of oil-
based stains.
[0067] Various nylon or polyester homo- or co-polymers may be used including,
but not
limited to, Nylon 6, Nylon 6,6, polyethylene terephthalate and polybutylene
terephthalate.
Preferably, the nylon comprises Nylon 6,6 homopolymer having a molecular
weight in the
region of from 5000 to 30000 Daltons, preferably from 10000 to 20000 Daltons,
most
preferably from 15000 to 16000 Daltons. The polyester will typically have a
molecular
weight corresponding to an intrinsic viscosity measurement in the range of
from 0.3-1.5
dl/g as measured by a solution technique such as ASTM D-4603.
[0068] Optionally, copolymers of the above polymeric materials may be employed
for the
purposes of the invention. Specifically, the properties of the polymeric
materials may be
tailored to specific requirements by the inclusion of monomeric units which
confer
particular properties on the copolymer. Thus, the copolymers may be adapted to
attract
particular staining materials by including monomer units in the polymer chain
which, inter
alia, are ionically charged, or include polar moieties or unsaturated organic
groups.
Examples of such groups may include, for example, acid or amino groups, or
salts thereof,
or pendant alkenyl groups.
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[0069] The polymeric particles are of such a shape and size as to allow for
good
flowability and intimate contact with the textile fibre. A variety of shapes
of particles can be
used, such as cylindrical, spherical or cuboid; appropriate cross-sectional
shapes can be
employed including, for example, annular ring, dog-bone and circular. Most
preferably,
however, said particles comprise cylindrical or spherical beads.
[0070] The particles may have smooth or irregular surface structures and can
be of solid
or hollow construction. Particles are of such a size as to have an average
mass of 1-35
mg, preferably from 10-30 mg, more preferably from 12-25 mg, and with a
surface area of
10-120 mm2, preferably from 15-50 mm2, more preferably from 20-40 mm2.
[0071] In the case of cylindrical beads, the preferred particle diameter is in
the region of
from 1.0 to 6.0 mm, more preferably from 1.5 to 4.0 mm, most preferably from
2.0 to 3.0
mm, and the length of the beads is preferably in the range from 1.0 to 4.0 mm,
more
preferably from 1.5 to 3.5 mm, and is most preferably in the region of 2.0 to
3.0 mm.
[0072] Typically, for spherical beads, the preferred diameter of the sphere is
in the region
of from 1.0 to 6.0 mm, more preferably from 2.0 to 4.5 mm, most preferably
from 2.5 to 3.5
mm.
[0073] In order to provide additional lubrication to the cleaning system and
thereby
improve the transport properties within the system, water is added to the
system. Thus,
more efficient transfer of the at least one cleaning material to the substrate
is facilitated,
and removal of soiling and stains from the substrate occurs more readily.
Optionally, the
soiled substrate may be moistened by wetting with mains or tap water prior to
loading into
the apparatus of the invention. In any event, water is added to the rotatably
mounted
cylindrical cage of the apparatus according to the invention such that the
washing
treatment is carried out so as to achieve a wash water to substrate ratio
which is preferably
between 2.5:1 and 0.1:1 w/w; more preferably, the ratio is between 2.0:1 and
0.8:1, with
particularly favourable results having been achieved at ratios such as 1.75:1,
1.5:1, 1.2:1
and 1.1:1. Most conveniently, the required amount of water is introduced into
the rotatably
mounted cylindrical cage of the apparatus according to the invention after
loading of the
soiled substrate into said cage. An additional amount of water will migrate
into the cage
during the circulation of the solid particulate cleaning material, but the
amount of carry over
is minimised by the action of the separating means.
[0074] Whilst, in one embodiment, the method of the invention envisages the
cleaning of
a soiled substrate by the treatment of a moistened substrate with a
formulation which
essentially consists only of a multiplicity of polymeric particles, in the
absence of any
further additives, optionally in other embodiments the formulation employed
may
additionally comprise at least one cleaning agent. Said at least one cleaning
agent may
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include at least one cleaning material. Preferably, the at least one cleaning
material
comprises at least one detergent composition. Optionally, said at least one
cleaning
material is mixed with said polymeric particles but, in a preferred
embodiment, each of said
polymeric particles is coated with said at least one cleaning material.
[0075] The principal components of the detergent composition comprise cleaning
components and post-treatment components.
Typically, the cleaning components
comprise surfactants, enzymes and bleach, whilst the post-treatment components
include,
for example, anti-redeposition additives, perfumes and optical brighteners.
[0076] However, the detergent formulation may optionally include one or more
other
additives such as, for example builders, chelating agents, dye transfer
inhibiting agents,
dispersants, enzyme stabilizers, catalytic materials, bleach activators,
polymeric dispersing
agents, clay soil removal agents, suds suppressors, dyes, structure
elasticizing agents,
fabric softeners, starches, carriers, hydrotropes, processing aids and/or
pigments.
[0077] Examples of suitable surfactants may be selected from non-ionic and/or
anionic
and/or cationic surfactants and/or ampholytic and/or zwitterionic and/or semi-
polar
nonionic surfactants. The surfactant is typically present at a level of from
about 0.1%, from
about 1%, or even from about 5% by weight of the cleaning compositions to
about 99.9%,
to about 80%, to about 35%, or even to about 30% by weight of the cleaning
compositions.
[0078] The compositions may include one or more detergent enzymes which
provide
cleaning performance and/or fabric care benefits. Examples of suitable enzymes
include,
but are not limited to, hemicellulases, peroxidases, proteases, other
cellulases, other
xylanases, lipases, phospholipases, esterases, cutinases, pectinases,
keratanases,
reductases, oxidases, phenoloxidases, lipoxygenases, ligninases, pullulanases,
tannases,
pentosanases, malanases, [beta]-glucanases, arabinosidases, hyaluronidase,
chondroitinase, laccase, and amylases, or mixtures thereof. A typical
combination may
comprise a mixture of enzymes such as protease, lipase, cutinase and/or
cellulase in
conjunction with amylase.
[0079] Optionally, enzyme stabilisers may also be included amongst the
cleaning
components. In this regard, enzymes for use in detergents may be stabilised by
various
techniques, for example by the incorporation of water-soluble sources of
calcium and/or
magnesium ions in the compositions.
[0080] The compositions may include one or more bleach compounds and
associated
activators. Examples of such bleach compounds include, but are not limited to,
peroxygen
compounds, including hydrogen peroxide, inorganic peroxy salts, such as
perborate,
percarbonate, perphosphate, persilicate, and mono persulphate salts (e.g.
sodium
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perborate tetrahydrate and sodium percarbonate), and organic peroxy acids such
as
peracetic acid, monoperoxyphthalic acid, diperoxydodecanedioic acid, N,N'-
terephthaloyl-
di(6-aminoperoxycaproic acid), N,N'-phthaloylaminoperoxycaproic acid
and
amidoperoxyacid. Bleach activators include, but are not limited to, carboxylic
acid esters
such as tetraacetylethylenediamine and sodium nonanoyloxybenzene sul phonate.
[0081] Suitable builders may be included in the formulations and these
include, but are
not limited to, the alkali metal, ammonium and alkanolammonium salts of
polyphosphates,
alkali metal silicates, alkaline earth and alkali metal carbonates,
aluminosilicates,
polycarboxylate compounds, ether hydroxypolycarboxylates, copolymers of maleic
anhydride with ethylene or vinyl methyl ether, 1,3,5-trihydroxybenzene-2,4,6-
trisulphonic
acid, and carboxymethyl-oxysuccinic acid, various alkali metal, ammonium and
substituted
ammonium salts of polyacetic acids such as ethylenediamine tetraacetic acid
and
nitrilotriacetic acid, as well as polycarboxylates such as mellitic acid,
succinic acid,
oxydisuccinic acid, polymaleic acid, benzene
1,3,5-tricarboxylic acid,
carboxymethyloxysuccinic acid, and soluble salts thereof.
[0082] The compositions may also optionally contain one or more copper, iron
and/or
manganese chelating agents and/or one or more dye transfer inhibiting agents.
[0083] Suitable polymeric dye transfer inhibiting agents include, but are not
limited to,
polyvinylpyrrolidone polymers, polyamine N-oxide polymers, copolymers of N-
vinylpyrrolidone and N-vinylimidazole, polyvinyloxazolidones and
polyvinylimidazoles or
mixtures thereof.
[0084] Optionally, the detergent formulations can also contain dispersants.
Suitable
water-soluble organic materials are the homo- or co-polymeric acids or their
salts, in which
the polycarboxylic acid may comprise at least two carboxyl radicals separated
from each
other by not more than two carbon atoms.
[0085] Said anti-redeposition additives are physico-chemical in their action
and include,
for example, materials such as polyethylene glycol, polyacrylates and carboxy
methyl
cellulose.
[0086] Optionally, the compositions may also contain perfumes Suitable
perfumes are
generally multi-component organic chemical formulations which can contain
alcohols,
ketones, aldehydes, esters, ethers and nitrile alkenes, and mixtures thereof.
Commercially
available compounds offering sufficient substantivity to provide residual
fragrance include
Galaxolide
(1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta(g)-2-benzopyran),
Lyral (3- and 4-(4-hydroxy-4-methyl-pentyl) cyclohexene-1-carboxaldehyde and
Ambroxan
((3aR, 5aS,9aS,9bR)-3a,6, 6, 9a-tetramethy1-2 ,4 ,5, 5a,7,8, 9, 9b-octahydro-
1H-benzo[e][1]
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benzofuran). One example of a commercially available fully formulated perfume
is Amour
Japonais supplied by Symrise AG.
[0087] Suitable optical brighteners fall into several organic chemical
classes, of which the
most popular are stilbene derivatives, whilst other suitable classes include
benzoxazoles,
benzimidazoles, 1,3-dipheny1-2-pyrazolines, coumarins, 1,3,5-triazin-2-yls and
naphthalimides. Examples of such compounds include, but are not limited to,
4,4'-bis[[6-
anilino-4(methylamino)-1,3,5-triazin-2-yl]amino]stilbene-2,2'-disulphonic
acid, 4,4'-bis[[6-
anilino-4-[(2-hydroxyethyl)methylamino]-1,3,5-triazin-2-yl]amino]stilbene-2,2'-
disulphonic
acid, disodium salt, 4,4'-
Bis[[2-anilino-4-[bis(2-hydroxyethyDamino]-1,3,5-triazin-6-
yl]amino]stilbene-2,2'-disulphonic acid, disodium salt, 4,4'-bis[(4,6-
dianilino-1,3,5-triazin-2-
yl)amino]stilbene-2,2'-disulphonic acid, disodium salt, 7-diethylamino-4-
methylcoumarin,
4,4'-Bis[(2-anilino-4-morpholino-1,3,5-triazin-6-yl)amino]-2,2'-
stilbenedisulphonic acid,
disodium salt, and 2,5-bis(benzoxazol-2-yl)thiophene.
[0088] Said agents may be used either alone or in any desired combination and
may be
added to the cleaning system at appropriate stages during the cleaning cycle
in order to
maximise their effects.
[0089] In any event, however, when the method of the invention is performed in
the
presence of at least one additional cleaning agent, the quantity of said
cleaning agent
required in order to achieve satisfactory cleaning performance is
significantly reduced from
the quantities required with the conventional methods of the prior art. This,
in turn, has
beneficial effects in terms of the reduced quantity of rinse water that is
subsequently
required to be used.
[0090] The ratio of solid particulate cleaning material to substrate is
generally in the
range of from 0.1:1 to 10:1 w/w, preferably in the region of from 0.5:1 to 5:1
w/w, with
particularly favourable results being achieved with a ratio of between 1:1 and
3:1 w/w, and
especially at around 2:1 w/w. Thus, for example, for the cleaning of 5 g of
fabric, 10 g of
polymeric particles, optionally coated with surfactant, would be employed in
one
embodiment of the invention. The ratio of solid particulate cleaning material
to substrate is
maintained at a substantially constant level throughout the wash cycle.
[0091] The apparatus and the method of the present invention may be used for
either
small or large scale batchwise processes and find application in both domestic
and
industrial cleaning processes. The apparatus of the present invention may be
used to
carry out conventional washing processes as well as for the performance of the
claimed
method of the present invention.
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[0092] As previously noted, the method of the invention finds particular
application in the
cleaning of textile fibres. The conditions employed in such a cleaning system
do, however,
allow the use of significantly reduced temperatures from those which typically
apply to the
conventional wet cleaning of textile fabrics and, as a consequence, offer
significant
5 environmental and economic benefits. Thus, typical procedures and
conditions for the
wash cycle require that fabrics are generally treated according to the method
of the
invention at, for example, temperatures of between 5 and 95 C for a duration
of between 5
and 120 minutes in a substantially sealed system. Thereafter, additional time
is required
for the completion of the rinsing and bead separation stages of the overall
process, so that
10 the total duration of the entire cycle is typically in the region of 1
hour. The preferred
operating temperatures for the method of the invention are in the range of
from 10 to 60 C
and, more preferably, from 15 to 40 C.
[0093] The cycle for removal of solid particulate material may optionally be
performed at
room temperature and it has been established that optimum results are achieved
at cycle
15 times of between 2 and 30 minutes, preferably between 5 and 20 minutes.
[0094] The results obtained are very much in line with those observed when
carrying out
conventional washing and laundering procedures with textile fabrics. The
extent of
cleaning and stain removal achieved with fabrics treated by the method of the
invention is
seen to be very good, with particularly outstanding results being achieved in
respect of
20 hydrophobic stains and aqueous stains and soiling, which are often
difficult to remove.
The energy requirement, the total volume of water used, and the detergent
consumption of
the method of the invention are all significantly lower than those levels
associated with the
use of conventional aqueous washing procedures, again offering significant
advantages in
terms of cost and environmental benefits.
[0095] Additionally, it has been demonstrated that re-utilisation of the
polymer particles is
possible, allowing for the performance of multiple washes with the same solid
particulate
cleaning material. Re-use of the particles in this way for repeat cleaning
procedures
provides significant economic benefits and the achievement of satisfactory
results after
multiple washes is assisted by the nature of the process, which relies on
continuous
cleaning of the particulate cleaning material as an integral part of the
procedure, although
it generally found that some deterioration in performance is eventually
observed.
[0096] In a typical example of an operating cycle according to the method of
the
invention, additional cleaning agents are employed. Said additional cleaning
agents may
be added to the lower chamber of said apparatus with said solid particulate
cleaning
material, optionally heated to the desired temperature therein, and introduced
via the first
recirculation means into the cylindrical cage. Preferably, however, said
additional cleaning
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agents are pre-mixed with water, which mixture may optionally be heated before
addition
to said cylindrical cage via said multiplicity of delivery means attached to
said stationary
member. Optionally, this addition may be carried out using one or more spray
nozzles in
order to better distribute said cleaning agents in the washload.
[0097] Thereafter, an initial addition of solid particulate cleaning material
(approximately
50 kg) is added to a washload of soiled substrate (25 kg) in the rotatably
mounted
cylindrical cage of 98 cm diameter, after which rotation of the cage commences
at around
40 rpm. Thereafter, recirculation of solid particulate cleaning material is
achieved by
pumping into said rotatably mounted cylindrical cage via the separating means
approximately every 30 seconds throughout the duration of the wash cycle,
which may
typically continue for around 30 minutes. The system is thereby designed to
pump and
add solid particulate cleaning material at a sufficient rate to maintain
roughly the same
level of solid particulate cleaning material in the rotatably mounted
cylindrical cage
(approximately 2:1 by weight, for 50 kg of beads and 25 kg of cloth)
throughout the wash.
[0098] Thus, during the wash cycle, the solid particulate cleaning material is
continually
falling out of the rotatably mounted cylindrical cage through its
perforations, and is being
recycled and added, together with fresh cleaning material, via the separating
means and
multiplicity of delivery means attached to the stationary member. This process
may either
be controlled manually, or operated automatically. The rate of exit of the
solid particulate
cleaning material from the rotatably mounted cylindrical cage is essentially
controlled by
means of its specific design. The key parameters in this regard include the
size of the
perforations, the number of perforations and the pattern of the perforations.
[0099] Generally, the perforations are sized at around 2-3 times the average
particle
diameter of the solid particulate cleaning material which, in a typical
example, results in
perforations having a diameter of no greater than 10.0 mm. Up to 60% of the
surface area
of the cylindrical walls of the cage typically comprises perforations.
[00100] The rate of exit of the solid particulate cleaning material from the
rotatably
mounted cylindrical cage is also affected by the speed of rotation of said
cage, with higher
rotation speeds increasing the centripetal force so as to increase the
tendency to push the
solid particulate cleaning material out of the perforations. However, higher
cage rpm
values also compress the substrate being cleaned, so as to trap the cleaning
material
within folds thereof. The most suitable rotation speeds are, therefore,
generally found to
be between 30 and 40 rpm at 98 cm cage diameter, or those which generate G
values of
between 0.49 and 0.88. The maximum rotation speed in order to avoid bead
trapping in
garments is found to be around 42 rpm (G = 0.97).
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[00101] In addition, the moisture level in the wash also has an effect, with
wetter
substrates tending to retain cleaning material for a longer time than drier
substrates.
Consequently, overwetting of substrate can, if necessary, be employed in order
to further
control the rate of exit of solid particulate cleaning material.
[00102] On completion of the wash cycle, addition of solid particulate
cleaning material to
the rotatably mounted cylindrical cage is ceased, and the cage is rotated for
a short time
(about 2 minutes) at low rpm (30-40 rpm; G = 0.49-0.88) to allow the bulk of
the solid
particulate cleaning material to leave the cage. The cage is then rotated at
high speed
(between 300 and 800 rpm; G = 49.3-350.6) for about 2 minutes in order to
extract some
liquid and dry the substrate to an extent. The rotation speed is then returned
to the same
low rpm as in the wash cycle in order to complete the removal of cleaning
material; this
generally takes around 20 minutes.
[00103] The method of the invention has been shown to be particularly
successful in the
removal of cleaning material from the cleaned substrate after washing, and
tests with
cylindrical polyester beads, and nylon beads comprising Nylon 6,6 polymer,
have indicated
bead removal efficacy such that on average <20 beads per garment remain in the
washload at the end of the bead separation cycle. Generally, this can be
further reduced
to an average of <10 beads per garment and, in optimised cases wherein a 20
minute
separation cycle is employed, an average of <5 beads per garment is typically
achieved.
[00104] Following said bead removal operation a series of rinses is carried
out, wherein
additional water is sprayed via the delivery means into the rotatably mounted
cylindrical
cage in order to effect complete removal of any additional cleaning agent
employed in the
cleaning operation. In an embodiment of the invention, said delivery means
incorporate
one or more spray nozzles through which said water is sprayed, these nozzles
being
attached to said stationary member. The use of said spray nozzles has been
shown to
better distribute the rinsing water in the washload. By this means the overall
water
consumption during the rinsing operation can also be minimised (3:1 rinse
water:cloth,
typically, per rinse). The cage is rotated at low speeds again during rinse
water addition
(30-40 rpm, G = 0.49-0.88 for 98 cm diameter cage), but after this operation
has ceased
the cage speed is once again increased to achieve a measure of drying of the
substrate
(300-800 rpm, G = 49.3-350.6). Subsequently, rotation speed is reduced and
returned to
the speed of the wash cycle so as to allow for final removal of any remaining
solid
particulate cleaning material. Said rinsing and drying cycles may be repeated
as often as
desired (3 times is typical).
[00105] Optionally, the bead removal operation may be carried out between
rinses, rather
than before the start of the series of rinses.
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[00106] Turning now to the Figures provided herewith, there are seen in
Figures 1 and 2
illustrations of an apparatus according to one embodiment of the invention.
Figure 1
shows a front view of a typical commercial bead washing machine wherein the
external
cladding panels have been removed for the sake of clarity. Thus, there can be
seen
housing means including housing chamber (1) wherein is located the rotatably
mounted
cylindrical cage (not shown). An access means in the form of door (2) is
located on the
front of the housing means and a multiplicity of delivery means comprising
bead inlet (3),
water spray nozzles (4) and fixed plumbing (5) are provided to allow the
cleaning materials
to enter the rotatably mounted cylindrical cage.
[00107] Specifically, door (2) is located on the axis of the cylindrical cage,
and hinged to
the right. Visible above the door are bead inlet (3), and a pair of water
spray nozzles (4).
The bead inlet (3) is positioned above the access means, and at the top end of
the
cylindrical cage, thereby enhancing the ability of the introduced cleaning
materials to mix
into a wash load during a wash cycle. The bead inlet is typically connected to
separation
means which provides a source of solid particulate cleaning material and, on
each side of
the bead inlet are located the water spray nozzles, which are connected via
fixed plumbing
(5) to the water supply. It will be noted that both the water spray nozzles
and the bead
inlet are located higher than could have been achieved if they were mounted on
the
access means (2). It is also the case that the use of multiple water spray
nozzles and
bead inlets may also be contemplated in order to provide quicker and more
uniform
addition of cleaning materials to the cylindrical cage.
[00108] Figure 2 shows the same view as Figure 1, but the front of the housing
chamber
(1) and the access means (2) have been removed so as provide a clearer
illustration of the
function of the stationary member. Thus, stationary member (6) is visible
outside the door
aperture and its outer edge (7) provides the interface with rotating front (8)
of the rotatably
mounted cylindrical cage. The gap around the circumference between the
stationary
member and the rotating cylindrical cage is required to be sufficiently small
to prevent
trapping of the soiled substrate and, in the illustrated embodiment, there is
a uniform gap
of 4 1 mm. The stationary member is fixedly attached to the inside of the
front of the
housing chamber (1) via attachment means comprising an attachment piece (9) by
the use
of fixing members (10). Due to the fixed attachment to the housing chamber,
the
attachment piece (9) ensures that the stationary member does not rotate.
[00109] Thus, it is seen that the placement of the bead inlet (3) and the
water spray
nozzles (4) is such that they are spaced at a distance from the access means
comprising
door (2), and they are securely attached to fixed plumbing (5) and fixed in
place by
attachment to the stationary member (6). This member (6) is securely attached
to the
CA 02884293 2015-03-09
WO 2014/037729 PCT/GB2013/052329
24
inside of the housing chamber (1) via attachment piece (9). This overcomes the
problems
associated with the incorporation of the delivery means in in the access means
and
eliminates the consequent difficulties which can occur when opening and
closing machine
doors. The apparatus of the present invention also facilitates the
incorporation of multiple
bead inlets and water spray nozzles in the washing machine housing, as
required.
[00110] Throughout the description and claims of this specification, the words
"comprise"
and "contain" and variations of them mean "including but not limited to", and
they are not
intended to (and do not) exclude other moieties, additives, components,
integers or steps.
Throughout the description and claims of this specification, the singular
encompasses the
plural unless the context otherwise requires. In particular, where the
indefinite article is
used, the specification is to be understood as contemplating plurality as well
as singularity,
unless the context requires otherwise.
[00111] Features, integers, characteristics, compounds, chemical moieties or
groups
described in conjunction with a particular aspect, embodiment or example of
the invention
are to be understood to be applicable to any other aspect, embodiment or
example
described herein unless incompatible therewith. All of the features disclosed
in this
specification (including any accompanying claims, abstract and drawings),
and/or all of the
steps of any method or process so disclosed, may be combined in any
combination,
except combinations where at least some of such features and/or steps are
mutually
exclusive. The invention is not restricted to the details of any foregoing
embodiments.
The invention extends to any novel one, or any novel combination, of the
features
disclosed in this specification (including any accompanying claims, abstract
and drawings),
or to any novel one, or any novel combination, of the steps of any method or
process so
disclosed.
[00112] The reader's attention is directed to all papers and documents which
are filed
concurrently with or previous to this specification in connection with this
application and
which are open to public inspection with this specification, and the contents
of all such
papers and documents are incorporated herein by reference.
