NOVEL CLEANING METHOD
Field of the Invention
[0001] The present invention relates to the aqueous cleaning of soiled substrates,
specifically textile fibres and fabrics, using a cleaning system comprising polymeric
particles. More specifically, the invention is concerned with a system wherein the
polymeric particles include antimicrobial agents which prevent mould and bacterial growth
on the particles which may occur after repeated uses in washing procedures.
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, whether in domestic washing machines or their
industrial equivalents (usually referred to as washer extractors), involve aqueous
submersion of fabrics followed by soil removal, aqueous soil suspension, and water
rinsing. In general, 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. the reduction of energy,
water and detergent consumption), and the need for efficient mechanical action in the
wash. For domestic washing in particular there are defined wash performance standards
specifically designed to discourage the use of such higher levels in practice, in addition to
the obvious cost penalties which are associated with such usage.
[0004] Current efficient domestic washing machines have made significant strides
towards minimising their consumptions of energy, water and detergent. EU Directive
92/75/CEE sets a standard which defines washing machine energy consumption in
kWh/cycle (cotton setting at 60°C), such that an efficient domestic washing machine will
typically consume <0.19 kWh/kg of washload in order to obtain an 'A' rating. If water
consumption is also considered, then 'A' rated machines use <9.7 litres/kg of washload.
[0005] Detergent dosage is then driven by manufacturer recommendations but, again, in
the domestic market, for a concentrated liquid formulation, a quantity of 35 ml (or 37 g) for
a 4-6 kg washload in soft and medium hardness water, increasing to 52 ml (or 55 g) for a
6-8 kg washload (or in hard water or for very dirty items) is typical (see, for example,
Unilever pack dosage instructions for Persil® Small & Mighty). Hence, for a 4-6 kg
washload in soft/medium water hardness, this equates to a detergent dosage of 7.4-9.2
g/kg whilst, for a 6-8 kg washload (or in hard water or for very dirty items), the range is 6.9-
9.2 g/kg.
[0006] Energy, water and detergent consumptions in the industrial washing process
(washer-extractors) are considerably different, however, and usages of all three resources
are less constrained, since these are the principal factors in reducing cycle time - which is,
of course, more of a consideration than in the case of domestic use. For a typical
industrial washer extractor (25 kg washload rated and above), energy consumption is 0.30-
1.0 kWh/kg, water is at 20-30 litres/kg, and detergent is much more heavily dosed than for
domestic washing. The exact level of detergent used will depend on the amount of soiling,
but a range of 20-100 g/kg is representative.
[0007] Thus, it can be taken from the above discussion that it is the performance levels
in the domestic sector which set the highest standard for an efficient fabric washing
process, and that these are: an energy consumption of <0.19 kWh/kg, a water usage of
<9.7 litres/kg, and a detergent dosage of approximately 8.0 g/kg. However, as previously
observed, it is becoming increasingly difficult to reduce the water (and, hence, energy and
detergent) levels in a purely aqueous process, due to the minimum requirement to wet the
fabric thoroughly, the need to provide sufficient excess water to suspend the soil removed
in an aqueous liquor and, finally, the necessity to rinse the fabric.
[0008] Heating of the wash water is then the principal use of energy, and a minimum
level of detergent becomes necessary in order for an effective concentration to be reached
at the operating wash temperature. Means to improve mechanical action without
increasing the water level used would, therefore, make any aqueous wash process
significantly more efficient (i.e. yield further reductions in energy, water and detergent
consumption). It should be noted that mechanical action itself has a direct effect on the
detergent level, since the greater the level of soil removal which is achieved through
physical force, the less that is required of the detergent chemistry. However, increasing
the mechanical action in a purely aqueous washing process has certain associated
drawbacks. Fabric creasing readily occurs in such processes, and this acts to concentrate
the stresses from mechanical action at each crease, resulting in localised fabric damage.
Prevention of such fabric damage (i.e. fabric care) is of primary concern to the domestic
consumer and the industrial user.
[0009] In the light of these challenges which are associated with aqueous washing
processes, the present inventors have previously devised a new approach to the problem,
which 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.
[0010] Thus, in WO-A-2007/1 28962, 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 comprise, for example,
particles of polyamides, polyesters, polyalkenes, polyurethanes or their copolymers but,
most preferably, are in the form of nylon beads.
[0011] The use of this polymeric cleaning method, however, presents a requirement for
the cleaning particles to be efficiently separated from the cleaned substrate at the
conclusion of the cleaning operation, and this issue is addressed in WO-A-20 10/094959,
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.
[0012] In co-pending WO-A-20 11/064581 , there is provided a further apparatus which
facilitates efficient separation of polymeric cleaning particles from the cleaned substrate at
the conclusion of the cleaning operation, and which 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 requiring
attachment of the outer skin to the drum during a wash cycle, after which the skin is
removed prior to operating a separation cycle to remove the cleaning particles, following
which the cleaned substrate is removed from the drum.
[0013] In a further development of the apparatus of WO-A-20 11/064581 , there is
disclosed in co-pending WO-A-20 11/098815 a process and apparatus which provides for
continuous circulation of the polymeric cleaning particles during the cleaning process, and
thereby dispenses with the requirement for the provision of an outer skin.
[0014] Further benefits in terms of reduced power and consumable requirements for the
cleaning method originally proposed in WO-A-2007/1 28962 have been disclosed in co
pending GB Patent Application No. 1018318.4, where the technology has been refined to
achieve at least equivalent cleaning performance whilst employing significantly reduced
levels of detergents and much lower process temperatures.
[0015] The apparatus and methods disclosed in the foregoing prior art documents have
been highly successful in providing an efficient means of polymeric cleaning and stain
removal which also yields significant economic and environmental benefits. The move to
much lower wash temperatures has been particularly beneficial in this regard. As a
consequence of the achievement of such lower temperatures, however, the need to control
hygiene in the washing machine has become significantly more important. Hotter wash
temperatures (>60°C) can provide some level of hygiene control via thermal disinfection,
since heat is an efficient destroyer of mould and bacteria, and higher temperatures are
increasingly beneficial. When these polymeric cleaning processes are run at lower
temperatures (<40°C), however, hygiene considerations are magnified compared to the
equivalent aqueous process, due to the presence of the polymeric particles. Said particles
provide a large additional surface area contained within the washing machine, on which
mould and bacteria can grow. The growth here can be accelerated by the fact that the
particles remain moist for a considerable time after each wash process has been run, and
the overall levels of mould and bacteria reached can be further increased if the machine
remains unused for extended periods of time.
[0016] The hygiene problem in the polymeric cleaning machine can, of course, be
controlled by similar means to that used in conventional aqueous domestic or industrial
washing, namely the use of higher wash temperatures as noted above, and/or chemical
additives in the wash water used. Suitable additives include chlorine derived bleaches
(e.g. sodium hypochlorite) or oxygen derived bleaches (e.g. hydrogen peroxide), but the
use of these materials has drawbacks in that they can decolour some garment types, and
generally promote fabric damage through chemical attack. The oxygen derived bleaches
also become less effective at lower wash temperatures (<40°C), even when used in
combination with suitable activators, e.g tetraacetyl ethylene diamine. Other additives
based on chloro compounds (e.g. liquid chlorophenols) can also be used, but with similar
drawbacks. Possibly the most benign means of achieving antimicrobial performance in the
wash water is via the addition of silver-containing materials (e.g. silver-containing zeolite
materials). Such approaches are expensive to consider, however, as they are effectively
applicable for single wash use only. Furthermore, as in all cases with chemical additives in
the wash water, there are effluent treatment considerations to take into account.
[0017] In looking to further develop the method of the cleaning process from WO-A-
2007/128962 and co-pending GB Patent Application No. 1018318.4, therefore, the present
inventors have now sought to provide a process which allows the aforementioned hygiene
deficiencies with polymeric cleaning to be overcome, particularly at low wash temperatures
(<40°C). Hence, in the presently claimed invention, the inventors, by means of the
addition of an antimicrobial agent to the polymeric particles, seek to provide a process in
which lower levels of mould and bacterial growth occur within the washing machine at all
times. The introduction of the antimicrobial agent in this way overcomes the drawbacks
which would be associated with single use addition into the wash water (i.e. fabric
damage, expense and effluent treatment considerations), and the action of the
antimicrobial agent is continuous over the lifetime of the polymeric particles, which are re
used many times in subsequent washes, as is common practice with this technology.
Statements of Invention
[0018] Thus, according to a first aspect of the present invention, there is provided a
method for aqueous cleaning of soiled substrates, said method comprising the treatment of
the moistened substrate with a formulation comprising a multiplicity of polymeric particles,
wherein said polymeric particles comprise at least one antimicrobial agent.
[0019] Said substrate may comprise any of a wide range of substrates, including, for
example, plastics materials, leather, paper, cardboard, metal, glass or wood. In practice,
however, said substrate most preferably comprises a textile fibre or fabric, which may
comprise either a natural material, such as cotton, or a synthetic textile material, for
example nylon 6,6 or a polyester.
[0020] Said antimicrobial agent inhibits the growth of microbes such as mould and
bacteria, and may comprise any readily commercially available product which is suitable
for such purposes, and which would be well known to the skilled person. Particularly
suitable agents include solid chlorophenol derivatives, such as 5-chloro-2-(2,4-
dichlorophenoxy)phenol, which is commercially available as Triclosan or Microban®, or its
derivatives, and silver-containing materials, most particularly silver-containing zeolite
materials, including products from the Bio-Gate™ Irgaguard® or HyGate™ ranges including,
for example, Bio-Gate™ BG-Tec Plus, Irgaguard® B 5000, Irgaguard® B 7000, HyGate™
4000 and HyGate™9000.
[0021] Said polymeric particles may comprise any of a wide range of different polymers.
Specifically, there may be mentioned polyalkenes such as polyethylene and
polypropylene, polyesters and polyurethanes. Preferably, however, said polymeric
particles comprise polyester or polyamide particles, most particularly particles of
polyethylene terephthalate, polybutylene terephthalate, nylon 6, and nylon 6,6, most
preferably in the form of beads. Said polyesters and polyamides are found to be
particularly effective for aqueous stain/soil removal, whilst polyalkenes are especially
useful for the removal of oil-based stains. Optionally, copolymers of the above polymeric
materials may be employed for the purposes of the invention.
[0022] Specifically, the properties of the polymeric materials may be tailored to particular
requirements by the inclusion of monomeric units which confer desired properties on the
copolymer. Thus, the polymers may be adapted to attract particular staining materials by
comprising co-monomers 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.
[0023] Furthermore, the polymeric particles may comprise either foamed or unfoamed
polymeric materials. Additionally, the polymeric particles may comprise polymers which
are either linear or crosslinked, and said particles may be solid or hollow.
[0024] Said antimicrobial agent is most conveniently introduced into said polymer
particles during extrusion of said polymer. Thus, the antimicrobial agent is especially
preferably added to the molten polymer prior to extrusion. In an alternative embodiment,
said polymer particles may be coated with said antimicrobial agent after extrusion.
[0025] Preferably, said antimicrobial agent is added to said polymer at a level of 0.1-
5.0%, (w/w), most preferably 0.5-2.5% (w/w), especially preferably 1.5-2.0% (w/w).
[0026] 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 which comprise at least one
antimicrobial agent, in the absence of any further additives, optionally in other
embodiments the formulation employed may further comprise at least one additional
cleaning agent. Preferably, the at least one additional cleaning agent comprises at least
one surfactant. Preferred surfactants comprise surfactants having detergent properties
and said additional cleaning agents preferably comprise detergent formulations. Said
surfactants may comprise anionic, non-ionic, cationic, ampholytic, zwitterionic and/or semipolar
non-ionic surfactants. Optionally, said at least one additional cleaning agent
comprises at least one enzyme and/or bleach. Preferably, said at least one additional
cleaning agent is mixed with said polymeric particles but, in an alternative embodiment,
each of said polymeric particles is coated with said at least one additional cleaning agent.
Further additives may be incorporated with said additional cleaning agent, as appropriate;
said additives may include, for example, anti-redeposition additives, optical brighteners,
perfumes, softeners and starch, which can enhance the appearance and other properties
of the cleaned substrate.
[0027] As previously stated, various polyester and/or polyamide homo- or co-polymers
may be used for the polymeric particles, including polyethylene terephthalate, polybutylene
terephthalate, nylon 6 and nylon 6,6. 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.
[0028] The ratio of polymeric particles 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 substrate, typically textile fabric, 10 g
of polymeric particles, optionally coated with surfactant, would be employed in one
embodiment of the invention. The ratio of polymeric particles to substrate is maintained at
a substantially constant level throughout the wash cycle.
[0029] The polymeric particles are of such a shape and size as to allow for good
flowability and intimate contact with the soiled substrate, which typically comprises a textile
fibre or fabric. 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. In preferred embodiments of the invention, said
particles are in the form of beads and, most preferably, comprise cylindrical or spherical
beads.
[0030] 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 1-50
mg, preferably from 10-30 mg, more preferably from 12-25 mg.
[0031] 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 5.0 mm, more
preferably from 1.5 to 3.5 mm, and is most preferably in the region of 2.0 to 3.0 mm.
[0032] 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.
[0033] The method of the invention may be applied to a wide variety of substrates, as
previously stated. More specifically, it is applicable across the range of natural and
synthetic textile fibres and fabrics, but it finds particular application in respect of nylon 6,6,
polyester and cotton fabrics.
[0034] Prior to treatment according to the method of the invention, the substrate is
moistened by wetting with water, to provide additional lubrication to the cleaning system
and thereby improve the transport properties within 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. Most conveniently, the substrate
may be wetted simply by contact with mains or tap water. Preferably, the wetting
treatment is carried out so as to achieve a substrate to water ratio of between 1:0.1 to 1:5
w/w; more preferably, the ratio is between 1:0.2 and 1:2, with particularly favourable
results having been achieved at ratios such as 1:0.2, 1: 1 , 1: 1 .2 and 1:2. However, in some
circumstances, successful results can be achieved with substrate to water ratios of up to
1:50, although such ratios are not preferred in view of the significant amounts of effluent
which are generated.
[0035] Suitable examples of apparatus for the execution of this method are disclosed in
WO-A-20 10/094959, WO-A-201 1/064581 and WO-A-201 1/098815. In preferred
embodiments of the invention, the claimed method additionally provides for separation and
recovery of the polymeric particles, which are then re-used in subsequent washes.
[0036] As a consequence of employing the cleaning method of the present invention,
excellent cleaning performance may be achieved whilst using significantly reduced levels
of detergents and much lower process temperatures. Thus, cleaning operations according
to the invention, whilst possible at temperatures up to 95°C, are typically carried out at
temperatures not exceeding 65°C, and optimum performance is generally achieved at 5-
35°C. It is at this lower end of the operational temperature range that the antimicrobial
polymeric particles ensure improved hygiene in the washing machine used.
[0037] According to a second aspect of the present invention, there is provided a
formulation for aqueous cleaning of soiled substrates, said formulation comprising a
multiplicity of polymeric particles, wherein said polymeric particles comprise at least one
antimicrobial agent.
[0038] Said substrate may comprise any of a wide range of substrates, including, for
example, plastics materials, leather, paper, cardboard, metal, glass or wood. In practice,
however, said substrate most preferably comprises a textile fibre or fabric, which may
comprise either a natural material, such as cotton, or a synthetic textile material, for
example nylon 6,6 or a polyester.
[0039] In one embodiment, said formulation may essentially consist only of said
multiplicity of polymeric particles which comprise at least one antimicrobial agent, but
optionally in other embodiments said formulation further comprises at least one additional
cleaning agent. Preferably, the at least one additional cleaning agent comprises at least
one surfactant. Preferred surfactants comprise surfactants having detergent properties
and said additional cleaning agents preferably comprise detergent formulations. Said
surfactants may comprise anionic, non-ionic, cationic, ampholytic, zwitterionic, and/or
semi-polar non-ionic surfactants. Optionally, said at least one additional cleaning agent
also comprises at least one enzyme and/or bleach.
[0040] Said formulation is preferably used in accordance with the method of the first
aspect of the invention, and is as defined in respect thereof. Additional additives may be
incorporated in said formulation, as appropriate; said additives may include, for example,
anti-redeposition additives, optical brighteners, perfumes, softeners and starch which can
enhance the appearance and other properties of the cleaned substrate.
[0041] The formulation and the method of the present invention may be used for either
small or large scale processes of both the batchwise and continuous variety and,
therefore, find application in both domestic and industrial cleaning processes. Excellent
performance can also result from the use of fluidised beds, and this is particularly the case
when the method of the invention is used for carrying out wet cleaning processes.
Brief Description of the Drawings
[0042] Embodiments of the invention are further described hereinafter with reference to
the accompanying drawings, in which:
Figures 1(a) and (b) show an apparatus suitable for use in the performance of the
method of the invention.
Detailed Description of the Invention
[0043] As previously noted, the antimicrobial agent is most conveniently introduced into
the polymer particles during extrusion of said polymer and is then added in a suitable
amount to the molten polymer prior to extrusion. Particularly suitable agents include solid
chlorophenol derivatives, such as 5-chloro-2-(2,4-dichlorophenoxy)phenol, which is
commercially available as Triclosan or Microban®, or its derivatives, and silver-containing
materials, including products from the Bio-Gate™, Irgaguard® or HyGate™ ranges including,
for example, Bio-Gate™ BG-Tec Plus, Irgaguard® B 5000, Irgaguard® B 7000, HyGate™
4000 and HyGate™ 9000. Preferably, said antimicrobial agent is added to said polymer at
a level of 0.1-5.0%, (w/w), most preferably 0.5-2.5% (w/w), especially preferably 1.5-2.0%
(w/w).
[0044] In alternative embodiments, the polymer particles may be coated with the
antimicrobial agent after extrusion in which case the particles are suitably placed in a
container with an appropriate amount of the antimicrobial agent, and the preferably sealed
container is agitated for, typically, 15-30 minutes at temperatures at or just above ambient
temperature. The coated particles are then removed from the container and are ready for
use in cleaning processes.
[0045] In a typical operation of a cleaning cycle according to the method of the invention,
soiled garments are first placed into a rotatably mounted cylindrical cage of a cleaning
apparatus according to the method described in WO-A-201 1/098815. Such an apparatus
is illustrated in Figures 1(a) and 1(b), wherein there is seen an apparatus comprising
housing means ( 1 ) having a first upper chamber having mounted therein a rotatably
mounted cylindrical cage in the form of drum (2) (perforations not shown) and a second
lower chamber comprising sump (3) located beneath said cylindrical cage. The apparatus
additionally comprises, as first recirculation means, bead and water riser pipe (4) which
feeds into separating means comprising a bead separation vessel (5), including filter
material, typically in the form of a wire mesh, and a bead release gate valve which feeds
into feeder means comprising bead delivery tube (6) mounted in cage entry (7). The first
recirculation means is driven by pumping means comprising bead pump (8). Additional
recirculation means comprises return water pipe (9), which allows water to return from the
bead separation vessel (5) to the sump (3) under the influence of gravity. The apparatus
also comprises access means shown as loading door (10), though which material for
cleaning may be loaded into drum (2). The main motor (20) of the apparatus, responsible
for driving the drum (2), is also depicted.
[0046] Following loading of the soiled garments into said apparatus, the polymeric
particles and the necessary amount of water, together with any required additional
cleaning agent, are added to said rotatably mounted cylindrical cage (2). Optionally, said
materials are introduced via the first recirculation means (4) into the cylindrical cage (2),
which is located in a first chamber of said apparatus. Alternatively, said polymeric particles
may, for example, be pre-mixed with water and added via the separating means (5)
located adjacent said cylindrical cage (2).
[0047] During the course of agitation by rotation of the cage (2), the fluids and a quantity
of the polymeric particles exit through perforations in the cage (2) and into the second
chamber (3) of the apparatus. Thereafter, the polymeric particles may be recirculated via
the first recirculation means (4) such that they are transferred to the separating means (5),
from which they are returned, in a manner controlled by control means, to the cylindrical
cage (2) for continuation of the washing operation. This process of continuous circulation
of the polymeric particles continues throughout the washing operation until cleaning is
completed.
[0048] Thus, the polymeric particles which exit through the perforations in the walls of
said rotatably mounted cylindrical cage (2) and into said second chamber (3) are
recirculated and reintroduced through said separation means (5) and, by operation of
control means, through the feeder means (6), back into said cage (2), thereby to continue
the cleaning operation.
[0049] Typically, a wash cycle according the method of the present invention comprises
the steps of:
(a) introducing polymeric particles, additional cleaning agent and water into a
second chamber of a cleaning apparatus of the type described in WO-A-
201 1/098815;
(b) agitating said polymeric particles, additional cleaning agent and water;
(c) loading at least one soiled substrate into the rotatably mounted cylindrical
cage of said apparatus via access means;
(d) closing the access means so as to provide a substantially sealed system;
(e) introducing said polymeric particles, additional cleaning agent and water
into said rotatably mounted cylindrical cage;
(f) operating the apparatus for a wash cycle, wherein said rotatably mounted
cylindrical cage is caused to rotate and wherein fluids and polymeric
particles 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 polymeric particles and
recycle used polymeric particles to separating means;
(h) operating control means so as to add said fresh and recycled polymeric
particles to said 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 garments.
[0050] Optionally, said polymeric particles, additional cleaning agent and water may be
introduced into said rotatably mounted cylindrical cage via recirculating means. More
preferably, however, said polymeric particles, additional cleaning agent and water are
introduced into said rotatably mounted cylindrical cage via dosing means such as, for
example, a fixedly mounted nozzle. Most conveniently, said nozzle may be fixedly
mounted on said access means.
[0051] Additional cleaning agents are advantageously employed in said method, as
further discussed below. Said additional cleaning agents may be added to the second
chamber of said apparatus with said polymeric particles and introduced, via the first
recirculation means, into the cylindrical cage. Alternatively, an additional cleaning agent is
pre-mixed with water and added to said cylindrical cage via the separating means during
step (e). More preferably, however, said additional cleaning agents are added to said
cylindrical cage via said dosing means. The method of the invention facilitates the use of
reduced quantities of said additional cleaning agents.
[0052] In preferred embodiments of the invention, said additional cleaning agents may be
added to said cylindrical cage in multiple dosing steps during the cleaning operation, rather
than in a single dosing step.
[0053] Preferably, pumping of said fresh and recycled polymeric particles proceeds at a
rate sufficient to maintain approximately the same level of particles in said rotatably
mounted cylindrical cage throughout the cleaning operation, and to ensure that the ratio of
particles to soiled garments stays substantially constant until the wash cycle has been
completed.
[0054] On completion of the wash cycle, feeding of polymeric particles into the rotatably
mounted cylindrical cage ceases and the speed of rotation of the cage is gradually
increased in order to effect a measure of drying of the cleaned substrate. Some polymeric
particles are removed at this stage. Typically, the cage is rotated at a rotation speed of
between 100 and 800 rpm in order to achieve drying; for a 98 cm diameter cage, a suitable
speed of rotation would be around 300 rpm. Subsequently, rotation speed is reduced and
returned to the speed of the wash cycle, so as to allow for final removal of the polymeric
particles. After separation, the polymeric particles are recovered in order to allow for re
use in subsequent washes.
[0055] Optionally, following initial drying at high rpm, 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 may be added to said cylindrical cage
via said separating means, by said dosing means, or by overfilling the second chamber of
said apparatus with water such that it enters the first chamber and thereby enters into said
rotatably mounted cylindrical 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 again increasing the speed of rotation to, typically, 100-800 rpm in order
to achieve a measure of drying of the substrate; a speed of rotation of around 300 rpm
would, once again, be appropriate for a 98 cm diameter cage. Said rinsing and drying
cycles may be repeated as often as desired.
[0056] 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.
[0057] Said polymeric particles are preferably subjected to a cleaning operation in said
second chamber by sluicing said chamber with clean water in the presence or absence of
a cleaning agent, which may be selected from at least one of surfactants, enzymes and
bleaches. Alternatively, cleaning of the polymeric particles may be achieved as a separate
stage in said rotatably mounted cylindrical cage. After cleaning, the polymeric particles are
recovered such that they are available for use in subsequent washes.
[0058] Generally, any remaining polymeric particles on said garments may be easily
removed by shaking the garments. If necessary, however, further remaining polymeric
particles may be removed by suction means, preferably comprising a vacuum wand.
[0059] The method of the invention is principally applied to the cleaning of substrates
comprising textile fibres and fabrics, and has been shown to be particularly successful in
achieving efficient cleaning of textile fabrics which may, for example, comprise either
natural materials, such as cotton, or man-made and synthetic textile materials, for example
nylon 6,6, polyester, cellulose acetate, or fibre blends thereof.
[0060] The volume of wash water added to the system is calculated so as to achieve a
fabric to wash water ratio which is preferably between 1:0.1 and 1:5 w/w; more preferably,
the ratio is between 1:0.2 and 1:2, with particularly favourable results having been
achieved at ratios such as 1:0.2, 1: 1 , 1: 1 .2 and 1:2. Most conveniently, the required
amount of water is introduced into the rotatably mounted cylindrical cage of the apparatus
after loading of the soiled substrate into said cage. An additional amount of water will
migrate into the cage during the circulation of the polymeric particles, but the amount of
water carry over is minimised by the action of the separating means.
[0061] As previously stated, preferred embodiments of the method of the invention
envisage the cleaning of soiled textile fibres or fabrics by treatment of the moistened fibres
or fabrics with a formulation which include a multiplicity of polymeric particles and further
comprise at least one additional cleaning agent. Said at least one additional cleaning
agent preferably comprises at least one detergent composition.
[0062] 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, optical brighteners, perfumes, softeners and
starch.
[0063] However, the detergent composition 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.
[0064] 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 may be present at a level of from about 0.1% to about
99.9% by weight of the cleaning composition, but is usually present from about 1% to
about 80%, more typically from about 5% to about 35%, or from about 5% to 30% by
weight of the cleaning compositions.
[0065] The detergent composition 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.
[0066] 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.
[0067] The detergent composition 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 monopersulphate salts (e.g.
sodium 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 sulfonate.
[0068] 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 hydroxypolycarboxylat.es, 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.
[0069] The detergent composition may also optionally contain one or more copper, iron
and/or manganese chelating agents and/or one or more dye transfer inhibiting agents.
Suitable polymeric dye transfer inhibiting agents include, but are not limited to,
polyvinylpyrrolidone polymers, polyamine N-oxide polymers, copolymers of Nvinylpyrrolidone
and N-vinylimidazole, polyvinyloxazolidones and polyvinylimidazoles or
mixtures thereof.
[0070] Optionally, the detergent formulation 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.
[0071] Suitable anti-redeposition additives are physico-chemical in their action and
include, for example, materials such as polyethylene glycol, polyacrylates and carboxy
methyl cellulose.
[0072] Optionally, the detergent composition may also contain perfumes. Suitable
perfumes are generally multi-component organic chemical formulations, a suitable
example of which is Amour Japonais supplied by Symrise® AG.
[0073] Appropriate 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-diphenyl-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'-disulfonic 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-hydroxyethyl)amino]-1 ,3,5-
triazin-6-yl]amino]stilbene-2,2'-disulfonic 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'-
stilbenedisulfonic acid, disodium salt, and 2,5-bis(benzoxazol-2-yl)thiophene.
[0074] 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.
[0075] The method of the present invention may be used for either small or large scale
batchwise or continuous processes and finds application in both domestic and industrial
cleaning processes.
[0076] As previously noted, the method of the invention finds particular application in the
cleaning of textile fibres and fabrics. 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 fibres and fabrics and, as a consequence,
offer significant environmental and economic benefits. Thus, typical procedures and
conditions for the wash cycle require that fibres and fabrics are generally treated according
to the method of the invention at, for example, temperatures of between 5 and 35°C for a
duration of between 5 and 45 minutes, optimally 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 the total duration of the entire cycle is typically in the
region of 1 hour.
[0077] It is at these lower wash temperatures that the efficacy of the presently claimed
invention is greatest. The inventors have sought, by addition of an antimicrobial agent to
the polymeric particles used, to provide a process in which lower levels of mould and
bacterial growth occur in the washing machine at all times. The introduction of the
antimicrobial agent in this way, overcomes the drawbacks associated with single use
addition into the wash water (i.e. fabric damage, expense and effluent treatment
considerations), and its action is continuous over the lifetime of the polymeric particles, as
said particles are re-used many times in subsequent washes, as is common practice with
this technology.
[0078] The invention will now be further illustrated, though without in any way limiting the
scope thereof, by reference to the following examples and associated illustrations.
Example
[0079] Approximately 80 kg of nylon 6,6 beads were supplied by Rhodia Operations,
Aubervilliers, France - grade 24FE3. This material was divided into individual samples of
approximately 20 kg, each of which was then dried for 3½ hours at 80°C in a desiccator.
The polymer beads and the appropriate amounts of a silver zeolite antimicrobial agent (Bio
Gate™ BG-Tec Plus) when used, were intimately mixed by shaking them together in a
sealed container, prior to extrusion using a Rondol 2 1 mm diameter twin screw extruder at
Smithers-RAPRA, Shawbury, UK. The four samples of polymer beads produced
contained 0% (as a control, comparative example), and 1.0, 1.5 and 2.0% w/w levels of the
Bio Gate™ BG-Tec Plus respectively. The twin screw extruder was operated with a screw
speed of 400 rpm, and with 8 sequential temperature settings down the barrel, namely:
zone 1 @ 240°C, zone 2 @ 250°C, zone 3 @ 260°C, zone 4 @ 265°C, zone 5 @ 265°C,
zone 6 @ 265°C, and zone 7 @ 265°C. The die plate (zone 8) was also maintained at
265°C. The extruded lace was then passed through a water bath to cool and form a
continuous solid strand, before being cut to form polymer beads of approximate
dimensions 4.0 x 1.7 x 1.7 mm.
[0080] In order to test the antimicrobial efficiency of these beads, 25 g aliquots of each
bead sample were inoculated with 6 ml of either pseudomonas aeruginosa (pa) at
approximately 3.1 x 103 cfu/ml (colony forming units/millilitre), or aspergillus brasiliensis
(ab) at approximately 1.4 x 103 cfu/ml. The inoculated beads were then stored at (31±1 )°C
for the duration of the study, and at various time points (t), samples of the beads
representing 1 ml of the inoculum (i.e. 5.17 g of beads/inoculum mixture) were removed to
9 ml of diluent and shaken vigorously. The resulting suspensions were tested using a
standard plate count method. Incubation was for 5 days at (31±1 )°C for the pa based
suspensions in tryptone soya agar growth medium, and for 5 days at (24±1 )°C for the ab
based suspensions in sabouraud dextrose agar growth medium. The results are shown in
Table 1.
Bead Sample Count (cfu/ml) Count (cfu/ml) Count (cfu/ml) Count (cfu/ml) Count (cfu/ml)
at t = 0 at t = 24 hours at t = 4 days at t = 7 days at t =14 days
24FE3 control pa = 3.1 x 10 pa = >10 pa = >10 pa = >10 pa = >10
ab = 1.4 x 103 ab = 1.5x103 ab = Not a = 2.1x104 a = 1.8x104
Measured
24FE3 + 1.0% pa = 3.1 x 10 pa = 1.3x10 pa = >10 pa = >10 pa = >10
w/w BG-Tec a = 1.4 x 103 a = 1.5x103 a = Not ab = 1.4x102 a = 10
Plus Measured
24FE3 + 1.5% pa = 3.1 x 10 pa = 2.1x10 pa = 5.3x10 pa = 3.6x10s pa = >10
w/w BG-Tec a = 1.4 x 103 ab = 1.3x103 ab = Not a = 1.6x102 a = <10
Plus Measured
24FE3 + 2.0% pa = 3.1x1 0 pa = <10 pa = <10 pa = <10 pa = <10
w/w BG-Tec a = 1.4x103 a = 1x103 ab = Not ab = 1.5x102 a = <10
Plus Measured
TABLE 1 pa and a cfu/ml Results for the Inoculated Bead Samples
[0081] As can be seen from Table 1, there is a pronounced antimicrobial effect from the
24FE3 beads extruded with the 2.0% w/w BG-Tec Plus antimicrobial agent. This has
resulted in suppression of mould and bacterial growth in repeated use washing with these
antimicrobial beads in apparatus as described in WO-A-201 1/098815.
[0082] 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.
[0083] 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.
[0084] 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.

CLAIMS
1. A method for cleaning a soiled substrate, said method comprising the treatment of
the moistened substrate with a formulation comprising a multiplicity of polymeric particles,
wherein said polymeric particles comprise at least one antimicrobial agent.
2. A method as claimed in claim 1 wherein said antimicrobial agent comprises a solid
chlorophenol derivative or a silver-containing material.
3. A method as claimed in claim 2 wherein said solid chlorophenol derivative
comprises 5-chloro-2-(2,4-dichlorophenoxy)phenol or its derivatives.
4. A method as claimed in claim 2 wherein said silver-containing material comprises a
silver-containing zeolite material.
5. A method as claimed in any one of claims 1 to 4 wherein said antimicrobial agent is
introduced into said polymer particles during extrusion of said polymer or said polymer
particles are coated with said antimicrobial agent after extrusion.
6. A method as claimed in any preceding claim wherein said antimicrobial agent is
added to said polymer at a level of 0.1-5.0% (w/w).
7. A method as claimed in any one of claims 1 to 6 wherein said substrate comprises
a plastics material, leather, paper, cardboard, metal, glass or wood.
8. A method as claimed in any one of claims 1 to 6 wherein said substrate comprises
a textile fibre or fabric which is a natural or synthetic fibre or fabric.
9. A method as claimed in claim 8 wherein said natural or synthetic fibre or fabric
comprises cotton, nylon 6,6 or a polyester.
10. A method as claimed in any one of claims 1 to 9 wherein said substrate is wetted
by contact with mains or tap water.
11. A method as claimed in claim 10 wherein said substrate is wetted so as to achieve
a substrate to water ratio of between 1:0.1 to 1:5 w/w.
12. A method as claimed in any preceding claim wherein said formulation further
comprises at least one additional cleaning agent.
13. A method as claimed in claim 12 wherein said at least one additional cleaning
agent comprises at least one surfactant.
14. A method as claimed in claim 13 wherein said at least one surfactant comprises at
least one surfactant having detergent properties and said at least one additional cleaning
agent comprises at least one detergent formulation.
15. A method as claimed in claim 13 or 14 wherein said surfactant comprises at least
one anionic, non-ionic, cationic, ampholytic, zwitterionic and/or semi-polar non-ionic
surfactant.
16. A method as claimed in any one of claims 12 to 15 wherein said at least one
additional cleaning agent is mixed with said polymeric particles or is coated with said at
least one additional cleaning agent.
17. A method as claimed in any one of claims 12 to 16 wherein said at least one
additional cleaning agent also comprises at least one enzyme and/or bleach.
18. A method as claimed in any one of claims 14 to 17 wherein said detergent
formulation additionally comprises at least one additive selected from anti-redeposition
additives, optical brighteners, perfumes, softeners and starch.
19. A method as claimed in any one of claims 14 to 18 wherein said detergent
formulation includes one or more other additives selected from 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.
20. A method as claimed in any one of claims 8 to 19 wherein the ratio of said particles
to substrate is in the range of from 0.1 : 1 to 10:1 w/w.
2 1. A method as claimed in any preceding claim wherein said polymeric particles
comprise particles of polyalkenes, polyesters, polyamides or polyurethanes, or their
copolymers.
22. A method as claimed in claim 2 1 wherein said polyamide particles comprise nylon
beads.
23. A method as claimed in claim 22 wherein said nylon comprises Nylon 6,6
homopolymer having a molecular weight in the region of from 5000 to 30000 Daltons.
24. A method as claimed in any preceding claim wherein said polymeric particles are in
the shape of spheres, cubes or cylinders, and said particles are solid or hollow.
25. A method as claimed in claim 24 wherein said cylindrically shaped particles have
an average particle diameter in the region of from 1.0 to 6.0 mm and the length of said
particles is in the range of from 1.0 to 5.0 mm.
26. A method as claimed in any preceding claim wherein said particles have an
average mass in the region of from 1 to 50 mg.
27. A method as claimed in any preceding claim wherein said polymeric particles
comprise foamed or unfoamed polymeric materials and said polymers are either linear or
crosslinked.
28. A method as claimed in any preceding claim which comprises a batchwise process
or continuous process.
29. A method as claimed in any preceding claim wherein said process is carried out in
a fluidised bed.
30. A method as claimed in any preceding claim wherein said treatment is carried out
at a temperature of between 5° and 35°C.
3 1. A method as claimed in any preceding claim wherein said treatment is carried out
for a duration of between 5 and 45 minutes.
32. A formulation for cleaning a soiled substrate, said formulation comprising a
multiplicity of polymeric particles, wherein said polymeric particles comprise at least one
antimicrobial agent.
33. A formulation as claimed in claim 32 wherein said antimicrobial agent comprises a
solid chlorophenol derivative or a silver-containing material.
34. A formulation as claimed in claim 33 wherein said solid chlorophenol derivative
comprises 5-chloro-2-(2,4-dichlorophenoxy)phenol or its derivatives.
35. A formulation as claimed in claim 33 wherein said silver-containing material
comprises a silver-containing zeolite material.
36. A formulation as claimed in any one of claims 32 to 35 wherein said antimicrobial
agent is introduced into said polymer particles during extrusion of said polymer or said
polymer particles are coated with said antimicrobial agent after extrusion.
37. A formulation as claimed in any one of claims 32 to 36 wherein said antimicrobial
agent is added to said polymer at a level of 0.1-5.0% (w/w).
38. A formulation as claimed in any one of claims 32 to 37 wherein said polymeric
particles comprise particles of polyalkenes, polyesters, polyamides or polyurethanes, or
their copolymers.
39. A formulation as claimed in any one of claims 32 to 38 wherein said polymeric
particles are in the shape of spheres, cubes or cylinders, and said particles are solid or
hollow.
40. A formulation as claimed in any one of claims 32 to 39 wherein said polymeric
particles comprise foamed or unfoamed polymeric materials and said polymers are either
linear or crosslinked.
4 1. A formulation as claimed in any one of claims 32 to 40 wherein said formulation
further comprises at least one additional cleaning agent.
42. A formulation as claimed in claim 4 1 wherein said at least one additional cleaning
agent comprises at least one surfactant.
43. A formulation as claimed in claim 42 wherein said at least one surfactant comprises
at least one surfactant having detergent properties and said at least one additional
cleaning agent comprises at least one detergent formulation.
44. A formulation as claimed in claim 42 or 43 wherein said surfactant comprises at
least one anionic, non-ionic, cationic, ampholytic, zwitterionic and/or semi-polar non-ionic
surfactant.
45. A formulation as claimed in any one of claims 4 1 to 44 wherein said at least one
additional cleaning agent also comprises at least one enzyme and/or bleach.
46. A formulation as claimed in claim 43, 44 or 45 wherein said detergent formulation
additionally comprises at least one additive selected from anti-redeposition additives,
optical brighteners, perfumes, softeners and starch.
47. A formulation as claimed in any one of claims 43 to 46 wherein said detergent
formulation includes one or more other additives selected from 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.