U.S. patent application number 10/027160 was filed with the patent office on 2002-05-16 for non aqueous washing apparatus and method.
Invention is credited to Conrad, Daniel C., Estes, Kurt A., Kovich, Mark Bradley, Wright, Tremitchell L..
Application Number | 20020056163 10/027160 |
Document ID | / |
Family ID | 21935848 |
Filed Date | 2002-05-16 |
United States Patent
Application |
20020056163 |
Kind Code |
A1 |
Estes, Kurt A. ; et
al. |
May 16, 2002 |
Non aqueous washing apparatus and method
Abstract
Methods and apparatuses for washing fabric loads without water
or using water only as a co-solvent are disclosed. One method of
non-aqueous clothes washing includes the steps of disposing
clothing in a wash container, delivering a wash liquor to the
fabric load, the wash liquor comprising a substantially
non-reactive, non-aqueous, non-oleophilic, apolar working fluid and
at least one washing additive, applying mechanical energy to the
clothing and wash liquor for a sufficient amount of time to provide
fabric cleaning and, thereafter, substantially removing the wash
liquor from the fabric load. The working fluid may be selected from
the group consisting of perfluorocarbons, hydrofluoroethers,
fluoronated hydrocarbons and fluoroinerts.
Inventors: |
Estes, Kurt A.; (Lake
Zurich, IL) ; Conrad, Daniel C.; (Stevensville,
MI) ; Kovich, Mark Bradley; (St. Joseph, MI) ;
Wright, Tremitchell L.; (Granger, IN) |
Correspondence
Address: |
SONNENSCHEIN NATH & ROSENTHAL
P.O. BOX 061080
WACKER DRIVE STATION
CHICAGO
IL
60606-1080
US
|
Family ID: |
21935848 |
Appl. No.: |
10/027160 |
Filed: |
December 20, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10027160 |
Dec 20, 2001 |
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09520653 |
Mar 7, 2000 |
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09520653 |
Mar 7, 2000 |
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09038054 |
Mar 11, 1998 |
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60045072 |
Apr 29, 1997 |
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Current U.S.
Class: |
8/142 |
Current CPC
Class: |
D06L 1/08 20130101; D06L
1/02 20130101; D06F 43/007 20130101; D06L 1/04 20130101; C11D
11/0064 20130101; D06F 43/00 20130101; D06L 4/00 20170101 |
Class at
Publication: |
8/142 |
International
Class: |
D06L 001/00; D06F
001/00 |
Claims
1. A method for laundering a fabric load comprising the steps of:
disposing a fabric load in a wash container; delivering a wash
liquor to the fabric load, said wash liquor comprising a
substantially non-reactive, non-aqueous, non-oleophilic, apolar
working fluid and at least one washing additive; applying
mechanical energy to provide relative movement between said fabric
load and said wash liquor for a time sufficient to provide fabric
cleaning; and thereafter, substantially removing said wash liquor
from said fabric load.
2. A method as defined in claim 1, further comprising the step of
moving the fabric load during said delivering step.
3. A method as defined in claim 1, further comprising the step of
separating said at least one washing additive from said working
fluid after said removing step.
4. A method as defined in claim 3, further comprising the step of
filtering separated working fluid and reusing the filtered working
fluid.
5. A method as defined in claim 3, wherein in said separating step
washing additive is separated from the working fluid by a
gravimetric, vaporization, distillation or freeze distillation
separation methods.
6. A method as defined in claim 1, wherein said working fluid has a
low vapor pressure and said removing step comprises pumping the
wash liquor from the wash container and thereafter reducing the
pressure within the wash container to vaporize any remaining
working fluid from the fabric load.
7. A method as defined in claim 1, wherein said at least one
washing additive has a specific gravity lower than the specific
gravity of said working fluid by more than 50% and wherein said
removing step comprises draining and pumping said wash liquor from
the wash container to a first storage vessel, adding new working
fluid to said wash container, pumping and draining the added
working fluid from the wash container to the first storage vessel,
permitting the at least one washing additive and the working fluid
to gravimetrically separate in the first storage vessel,
determining the relative position of a boundary between the
separated washing additive and the working fluid in the first
storage vessel and removing the separated volume of working fluid
disposed below the boundary from the first storage vessel for
reuse.
8. A method as defined in claim 1, wherein said at least one
washing additive has a boiling point which differs from a boiling
point of said working fluid by at least about 20.degree. C. and
wherein said removing step comprises draining and pumping said wash
liquor from the wash container to a first storage vessel and
thereafter separating the at least one washing additive from the
working fluid in the first storage vessel by a distillation
method.
9. A method of laundering a fabric load comprising the steps of:
disposing a fabric load in an interior chamber of a wash container;
pressurizing the chamber to an elevated pressure of between about
15 atm to about 50 atm; delivering a wash liquor to the fabric load
in the pressurized chamber in the form of a mist, said wash liquor
comprising a substantially non-reactive, non-aqueous,
non-oleophilic, apolar working fluid and at least one washing
additive; applying mechanical energy to provide relative movement
between said fabric load and said mist for a time sufficient to
provide fabric cleaning; decreasing the pressure in the chamber to
volatilize said wash liquor; and removing the volatilized wash
liquor from the chamber and fabric load.
10. A method as defined in claim 9, wherein in said delivering
step, said at least one washing additive is added after said
working fluid is added to the fabric load.
11. A method as defined in claim 9, wherein in said delivering
step, said wash liquor is sprayed in the form of a mist through
high pressure jets onto the fabric load.
12. A method as defined in claim 9, wherein wash liquor is pumped
from the chamber and resprayed onto the fabric load.
13. A method as defined in claim 9, wherein in said applying step,
relative movement is provided by rotating the wash container about
a horizontal axis.
14. A method as defined in claim 9, further comprising the steps of
capturing and condensing the volatilized wash liquor for reuse.
15. An automatic washing apparatus for dry to dry laundering of a
fabric load in the home, said apparatus comprising: a sealed
pressurizable wash chamber; means for pressurizing the wash chamber
to pressures of from about 5 atm to about 50 atm; a wash basket
disposed in the wash chamber for receiving a fabric load; means for
dispensing a wash liquor having a vapor pressure less than the
vapor pressure of water onto the fabric load at a first pressure of
between 1 atm and 50 atm; means for agitating the wash liquor and
fabric load in the wash basket; means for substantially removing
the wash liquor from the wash basket; and means for reducing the
pressure in the wash container to a reduced second pressure less
than the first pressure to remove any remaining wash liquor from
the fabric load in vapor form.
16. An automatic washing apparatus as defined in claim 15, wherein
said dispensing means includes means for mixing a substantially
non-reactive, non-aqueous, non-oleophilic, apolar working fluid
with at least one washing additive to form said wash liquor.
17. An automatic washing apparatus as defined in claim 15, wherein
said dispensing means includes means for sequentially dispensing a
substantially non-reactive, non aqueous, non-oleophilic, apolar
working fluid to the fabric load and at least one washing additive
to the fabric load.
18. An automatic washing apparatus as defined in claim 15, wherein
said dispensing means includes means for sequentially dispensing at
least one washing additive to the fabric load and a substantially
non-reactive, non-aqueous, non-oleophilic, apolar working fluid to
the fabric load.
19. An automatic washing apparatus as defined in claim 15, wherein
said dispensing means dispenses the wash liquor in the form of a
mist.
20. An automatic washing apparatus as defined in claim 15, further
comprising means for separating working fluid from said at least
one washing additive in the removed wash liquor for reuse of the
working fluid.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention generally relates to apparatuses and
methods employed in the home for laundering clothing and fabrics.
More particularly, it relates to a new and improved method and
apparatus for home laundering of a fabric load using a wash liquor
comprising a multi-phase mixture of a substantially inert working
fluid and at least one washing additive.
[0002] In the Specification and claims, the terms "substantially
non-reactive" or "substantially inert" when used to describe a
component of a wash liquor or washing fluid, means a non-solvent,
non-detersive fluid that under ordinary or normal washing
conditions, e.g. at pressures of -10 to 50 atmospheres and
temperatures of from about 10.degree. to about 45.degree. C., does
not appreciably react with the fibers of the fabric load being
cleaned, the stains and soils on the fabric load, or the washing
additives combined with the component to form the wash liquor.
[0003] Home laundering of fabrics is usually performed in an
automatic washing machine and occasionally by hand. These methods
employ water as the major component of the washing fluid. Cleaning
additives such as detergents, enzymes, bleaches and fabric
softeners are added and mixed with the water at appropriate stages
of the wash cycle to provide cleaning, whitening, softening and the
like.
[0004] Although improvements in automatic washing machines and in
cleaning agent formulations are steadily being made, as a general
rule, conventional home laundering methods consume considerable
amounts of water, energy and time. Water-based methods are not
suitable for some natural fiber fabrics, such as silks, woolens and
linens, so that whole classes of garments and fabrics cannot be
home laundered, but instead, must be sent out for professional dry
cleaning. During water washing, the clothes become saturated with
water and some fibers swell and absorb water. After washing, the
water must be removed from the clothes. Typically, this is
performed in a two-step process including a hard spin cycle in the
washer and a full drying cycle in an automatic dryer. The hard spin
cycles tend to cause wrinkling which is not wanted. Even after
spinning, drying cycle times are undesirably long.
[0005] Non-aqueous washing methods employed outside the home are
known, but for various reasons, these methods are not suitable for
home use. Generally, the non-aqueous washing methods to date employ
substitute solvents in the washing fluid for the water used in home
laundering.
[0006] Conventional dry cleaning methods have employed halogenated
hydrocarbon solvents as a major component of a wash liquor. The
most commonly used halogenated hydrocarbon solvents used for dry
cleaning are perchloroethylene, 1,1,1-trichloroethane and CFC-113.
These solvents are ozone depleting and their use is now controlled
for environmental reasons. Moreover, many of these solvents are
suspected carcinogens that would require the use of a nitrogen
blanket. Accordingly, these dry cleaning solvents cannot be used in
the home.
[0007] Alternative dry cleaning methods employed petroleum-based or
Stoddard solvents in place of the halogenated hydrocarbon solvents.
The petroleum-based solvents are inflammable and smog-producing.
Accordingly, their commercial use is problematic and use of these
materials in the home is out of the question. U.S. Pat. No.
5,498,266 describes a method using petroleum-based solvents wherein
perfluorocarbon vapors are admixed with petroleum solvent vapors to
remove the solvents from the fabrics and provide improvements in
safety by reducing the likelihood of ignition or explosion of the
vapors.
[0008] A further non-aqueous solvent based washing method employs
liquid or supercritical carbon dioxide solvent as a washing liquid.
As described in U.S. Pat. No. 5,467,492, highly pressurized vessels
are required to perform this washing method. In accordance with
these methods, pressures of about 500 to 1000 psi are required.
Pressures of up to about 30 psi are approved for use in the home.
The high pressure conditions employed in the carbon dioxide create
safety hazards that make them unsuitable for residential use.
[0009] Various perfluorocarbon materials have been employed alone
or in combination with cleaning additives for washing printed
circuit boards and other electrical substrates, as described for
example in U.S. Pat. No. 5,503,681. Spray cleaning of rigid
substrates is very different from laundering soft fabric loads.
Moreover, cleaning of electrical substrates is performed in high
technology manufacturing facilities employing a multi-stage
apparatus which is not readily adapted for home use.
[0010] Accordingly, to overcome the disadvantages of prior art home
laundering methods, it is an object of the present invention to
provide a new and improved method and apparatus for laundering a
fabric load in the home employing a safe and effective,
environmentally-friendly, nonaqueous wash liquor.
[0011] It is another object of the present invention to provide a
new and improved apparatus for laundering a fabric load in the
home, which is safe and effective for a broad range of fabric
types, including natural fiber fabrics, such as woolens, linens and
silks.
[0012] It is a further object of the present invention to provide a
new and improved home laundering method and apparatus which
consumes less water, time and energy than conventional water-based
home laundering machines and methods.
[0013] It is still another object of the present invention to
provide a new and improved dry to dry home laundering method and
apparatus requiring less handling by the home user.
[0014] It is a further object of the present invention to provide a
new and improved home dry to dry laundering method and apparatus
which provides safe and effective fabric cleaning without
introducing wrinkling.
SUMMARY OF THE INVENTION
[0015] In accordance with these and other objects, the present
invention provides new and improved methods and apparatuses for
laundering a fabric load in the home. In an embodiment, a method
for laundering a fabric load is provided comprising the steps
of:
[0016] disposing a fabric load in a wash container;
[0017] delivering a wash liquor to the fabric load, said wash
liquor comprising a substantially non-reactive, non-aqueous,
non-oleophilic, apolar working fluid and at least one washing
additive;
[0018] applying mechanical energy to provide relative movement
between said fabric load and said wash liquor for a time sufficient
to provide fabric cleaning; and
[0019] thereafter, substantially removing said wash liquor from
said fabric load.
[0020] In a preferred embodiment, the working fluid is a liquid
under washing conditions and has a density of greater than 1.0. The
working fluid has a surface tension of less than or equal to 35
dynes/cm.sup.2. The oil solvency of the working fluid should be
greater than water without being oleophilic. Preferably, the
working fluid has an oil solvency as measured by KB value of less
than or equal to 30. The working fluid, also has a solubility in
water of less than about 10%. The viscosity of the working fluid is
less than the viscosity of water under ordinary washing conditions.
The working fluid has a pH of from about 6.0 to about 8.0.
Moreover, the working fluid has a vapor pressure less than the
vapor pressure of water and has a flash point of greater than or
equal to 145.degree. C. The working fluid is substantially
non-reactive under washing conditions with fabrics in the fabric
load, with the additives present in the at least one washing
additive and with oily soils and water soluble soils in the fabric
load.
[0021] The working fluid is substantially non-swelling to natural
fabrics present in the fabric load.
[0022] In an embodiment, the working fluid is a fluorine-containing
compound selected from the group consisting of: perfluorocarbons,
hydrofluoroethers, fluorinated hydrocarbons and fluoroinerts.
Preferably, the working fluid comprises a compound having the
formula:
(CF.sub.3(CF.sub.2).sub.n).sub.3N
[0023] wherein n is an integer of from 4 to 20.
[0024] In an embodiment, the at least one washing additive may be
selected from the group consisting of: surfactants, enzymes,
bleaches, ozone, ultraviolet light, hydrophobic solvents,
hydrophilic solvents, deodorizers, fragrances, antistatic agents
and anti-stain agents. Mixtures of any of these washing additives
may be used. A number of washing additives may be individually
mixed with working fluid and these mixtures may be sequentially
contacted with the fabric load in any desired order.
[0025] In an embodiment relative movement between the fabric load
and wash liquor is provided by moving the wash container in a
manner which moves the fabric load with respect to the wash liquor.
Relative movement may be provided by rotating the wash container
about an axis, horizontal or otherwise, or by rotating the wash
container about a vertical axis. Relative movement may be provided
by nutating the wash container about a vertical axis. Relative
movement may also be provided by pumping the wash liquor from the
wash container and respraying the wash liquor into the wash
container, as well as, by high pressure jetting of the wash liquor
into the wash container. Vibratory shaking of the wash container
may also be used to provide relative movement. Relative movement
may be provided by exposing the wash container to ultra-sonic
irradiation. Relative movement may also be provided by moving an
agitator within the wash container relative to the wash container,
or by reciprocally partially rotating the wash container with
respect to stator blades mounted in the wash container.
[0026] A major advantage provided by the present invention is that
it conserves time, water and energy.
[0027] Another advantage provided by the present invention is that
a dryer is not required, saving cost, energy and floor space.
[0028] A further advantage provided by the present invention is
that the preferred apparatus does not employ a hard spin cycle and
eliminates the need for a dryer so that home laundering methods and
apparatus are provided which are less noisy.
[0029] Still another advantage provided by the present invention is
that less sorting, transferring and handling of the fabric load is
required by the homeowner.
[0030] A further advantage provided by the present invention is
that home laundering in accordance with the invention is
substantially non-wrinkling so that no ironing is needed.
[0031] Still another advantage provided by the present invention is
that because the wash liquor is non-wetting to the fabric load, no
hard spin cycle is required, which in turn permits a washer to be
provided which does not need a suspension system, thereby reducing
cost, weight and energy.
[0032] A further advantage provided by the present invention is
that effective cleaning of wool, silk and linen in the home is
provided for the first time.
[0033] Other objects and advantages of the present invention will
become apparent from the following detailed description of the
Preferred Embodiments, taken in conjunction with the drawings, in
which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The invention will now be described in more detail, with
reference to the accompanying drawings, in which:
[0035] FIG. 1 is a perspective view of a combined washing apparatus
and working fluid storage unit made in accordance with the present
invention;
[0036] FIG. 2 is a schematic diagram of a washing apparatus and
ideal working fluid storage unit made in accordance with the
present invention;
[0037] FIG. 3 is a schematic diagram of another embodiment of a
washing apparatus and ideal working fluid storage unit made in
accordance with the present invention;
[0038] FIG. 4 is a flow chart illustrating a non-aqueous method of
laundering a fabric load in accordance with the present
invention;
[0039] FIG. 5 is a flowchart illustrating another non-aqueous
method of laundering a fabric load in accordance with the present
invention;
[0040] FIG. 6 is a flowchart illustrating another non-aqueous
method of laundering a fabric load in accordance with the present
invention;
[0041] FIG. 7 is a flowchart illustrating another non-aqueous
method of laundering a fabric load in accordance with the present
invention;
[0042] FIG. 8 is a flowchart illustrating another non-aqueous
method of laundering a fabric load in accordance with the present
invention;
[0043] FIG. 9 is a flowchart illustrating another non-aqueous
method of laundering a fabric load in accordance with the present
invention;
[0044] FIG. 10 is a flowchart illustrating another non-aqueous
method of laundering a fabric load in accordance with the present
invention;
[0045] FIG. 11 is a flowchart illustrating another non-aqueous
method of laundering a fabric load in accordance with the present
invention;
[0046] FIG. 12 is a flowchart illustrating another non-aqueous
method of laundering a fabric load in accordance with the present
invention;
[0047] FIG. 13 is a perspective view of another washing apparatus
made in accordance with the present invention;
[0048] FIG. 14 is a partial view of the washing apparatus shown in
FIG. 13; and
[0049] It should be understood that the drawings are not
necessarily to scale and that the embodiments are sometimes
illustrated by graphic symbols, phantom lines, diagrammatic
representations and fragmentary views. In certain instances,
details which are not necessary for an understanding of the present
invention or which render other details difficult to perceive may
have been omitted. It should be understood, of course, that the
invention is not necessarily limited to the particular embodiments
illustrated herein.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
[0050] An apparatus 10 for carrying out the method of laundering
fabric loads in accordance with the present invention is
illustrated. The apparatus 10 includes a washing apparatus 11
disposed adjacent to a working fluid storage unit 12. The washing
apparatus 11 includes a front door 13, preferably with a handle 14,
for placing a fabric load (not shown) in the washer 11. A control
panel 15 is disposed along the top of the washer 11, along a back
edge or other suitable location which makes it easy for the
consumer to operate.
[0051] As illustrated in FIG. 2, the washing apparatus 11 includes
a centrally disposed wash chamber 16 which receives a fabric load
(not shown). Working fluid is supplied to the wash chamber 16 from
the working fluid storage unit 12. The storage unit 12 includes a
generally centrally disposed tank 17 with an outlet conduit 18 and
an inlet conduit 19. In the embodiment illustrated in FIG. 2, the
working fluid is stored in the unit 12. Fluid then passes through
the outlet 18, through a filter 21 and through a three-way valve
22. When fluid is to be charged into the wash chamber 16, the valve
22 is open between conduits 23 and 24 and fluid flows through the
valve 22 into a compressor/condenser 25. The fluid is at least
partially condensed in the compressor/condensor 25 before it passes
through a heater/cooler unit 26 which, depending upon the working
fluid, will most likely remove heat from the at least partially
condensed gas stream so that the working fluid is converted into a
liquid form before entry into the wash chamber 16.
[0052] The combination of the fabric (e.g. clothes) and the working
fluid is then preferably agitated within the chamber 16 by way of
an agitation means (not shown in FIG. 2) for a relatively short
time period compared to currently-available automatic washers that
use water as a working fluid. After the wash cycle, a three-way
valve 27 is opened so that communication is established between
conduits 28 and 29. A discharge pump 31, having already been
activated, pumps the working fluid through the valve 27, through a
conduit 32, and into a dirt container shown at 33. In the dirt
container 33, the working fluid is vaporized, leaving any dirt
particles entrained in the fluid in the dirt container 33 and
permitting the gaseous working fluid to proceed through a conduit
34, through a filter 35, through the conduit 19 and back into the
storage tank 17.
[0053] In an alternative apparatus 10a illustrated in FIG. 3, a
washing apparatus 11 is again disposed adjacent to a storage unit
12 which also includes a storage tank 17 for containing the working
fluid. However, in the system 10a, the working fluid has a lower
vapor pressure at operating pressures and temperature and, hence,
is present within the storage tank 17 primarily as a liquid. To
charge the wash chamber 16, fluid flows out of the storage tank 17,
through the conduit 18 and through the filter 21. Again, a
three-way valve 22 is disposed between the filter 21 and the wash
chamber 16. In the embodiment 10a illustrated in FIG. 3, the
three-way valve 22 provides communication between the conduit 23
and either a pump 48 for pumping the fluid through a three-way
valve 36 and out a drain disposal 37 or, to a four-way valve shown
at 38.
[0054] To charge the wash chamber 16 with working fluid, the
four-way valve 38 is opened providing communication between
conduits 39 and 28, fluid entering the chamber 16 through the
conduit 28. Preferably, the fabric load (not shown) and working
fluid are tumbled or agitated for a few minutes before additives
are added to the chamber 16. Washing additives are added to the
chamber 16 by way of a dispenser 42 and recirculated working fluid
being pumped by the pump 31, through the conduit 32, through the
dispenser 42 and out a spray or mist port 43.
[0055] When washing additives are to be delivered to the washing
chamber 16, the four-way valve 38 is opened so that communication
is established between the conduit 28 and the conduit 29. The back
flush/recirculation pump 31 then pumps the fluid through the
conduit 32, through the dispenser 42 and out the delivery port 43.
Additives that have been disposed in the dispenser 42 are then
entrained in the fluid being recirculated to the washing chamber 16
through the delivery port 43. A perforated basket is preferably
disposed within the chamber 16 which permits particles and lint
material from the fabric to flow through the perforated walls of
the basket before being collected under the force of gravity in a
particle/lint trap 45. A conduit 46 provides communication between
the chamber 16 and a heater/cooler 26 for controlling the
temperature of the working fluid within the chamber 16. The
three-way valve 36, in a drain mode, establishes communication
between a conduit 48 and the conduit 37. The working fluid is not
normally drained from the washing chamber 16. Instead, it is
normally recirculated by way of the pathway defined by the conduit
28, four-way valve 38, conduit 29, pump 31, conduit 32, dispenser
42, conduit 34, filter 35 and conduit 19.
[0056] FIGS. 4-12 illustrate various methods of washing fabrics in
accordance with the present invention. For definitional purposes, a
fluid that possesses no detersive properties similar to those
properties found in conventional detergents, dry cleaning agents
and liquefied carbon dioxide will hereinafter be referred to as an
ideal working fluid (IWF). Examples of IWFs that can be utilized
with the methods and apparatuses of the present invention include
fluoroinerts, hydrofluoroethers, perfluorocarbons and similarly
fluorinated hydrocarbons.
[0057] Compounds that provide a detersive action that is required
to remove particulates, film soils and stains or that assist in the
removal of particulates, film soils and stains will hereinafter be
referred to as performance enhancers. These compounds include
enzymes, organic and inorganic bleaches, ozone, ultraviolet light
or radiation as well as polar and non-polar solvents.
[0058] A solvent that is different from the IWF in that its sole
purpose is to provide detersive properties not met by the
performance enhancers will hereinafter be referred to as a
co-solvent. Co-solvents that may be used in the methods and with
the apparatuses of the present invention include alcohols, ethers,
glycols, esters, ketones and aldehydes. A mixture of these
co-solvents with the IWF provides a system that is sufficiently
stable for a fabric washing application.
[0059] Turning to FIG. 4, a first step 60 in one method of
practicing the present invention is the loading of the washing
chamber shown at 16 in FIGS. 2 and 3. The chamber 16 should
preferably be capable of tumbling, agitating, nutating or otherwise
applying mechanical energy to the combination of the fabrics and
the IWF. A next step 61 includes the addition of the IWF in a
relatively small amount compared to conventional washing systems.
Specifically, an amount of approximately six (6) liters will be
satisfactory for a normal size load of fabrics or clothes by
conventional standards. The volume of IWF is less than a typical
water volume for a conventional system since the surface tension
and textile absorption of the IWF fluid is significantly less than
that for water. Following the introduction of the IWF at step 61,
the fabric (i.e. clothes) and IWF are tumbled slowly for a short
period of time at step 62. Then, performance enhancers as discussed
above, are added at step 63 to remove targeted contaminants in the
fabrics. Mechanical energy is then applied to the system for a
relatively short period compared to conventional aqueous systems at
step 64.
[0060] In preferred embodiments, the agitation time ranges from
about 2 minutes to about 5 minutes. In most embodiments and methods
of the present invention, there is no need for the agitation time
period to exceed more than 10 minutes. The combination of the
draining of the IWF and a soft spin is performed at step 65.
Because the IWF has a density greater than 1.0 g/ml and further
because the IWF is not absorbed by the fabrics to a large degree,
most of the IWF simply drains away from the fabric. However, the
application of a soft spin to the fabrics by rotating the washing
vessels shown at 16 in FIGS. 2 and 3 has been found effective to
remove any excess IWF. The soft spin need not be as fast as a
spinning cycle of a conventional washing machine that uses water.
Instead, the rotational speed is similar to that of a conventional
dryer, therefore eliminating the need for an elaborate suspension
system as presently required by conventional washing machines.
[0061] The combination of the IWF and performance enhancers are
captured at step 66. Water is added to this mixture at step 67 to
separate the IWF from the performance enhancers. Water will have a
greater affinity for the performance enhancers than the IWF.
Further, the IWF is immiscible in water. Accordingly, a gravity
separation technique can be employed at step 68 due to the
difference in the specific gravity of water and the IWF. Water and
the performance enhancers are disposed of at step 69 while the IWF
is filtered at step 70 and stored at step 71 for the next cycle.
Air is introduced to the fabric at step 72 to complete the drying
of the garments without the need for an additional or separate
drying apparatus.
[0062] An alternative method is illustrated in FIG. 5 which
includes a different recovery and separation process than that of
the method illustrated in FIG. 4. Instead of adding water to the
IWF performance enhancer mixture at step 67 and performing a
gravity separation at step 68 as illustrated in FIG. 4, the method
illustrated in FIG. 5 practices a fractional distillation
separation at step 73. Specifically, after the combination of the
IWF and performance enhancers is captured at step 66, either the
temperature of the mixture is increased to the IWF boiling point or
the pressure is reduced to the point where the IWF begins to boil
(or a combination of the two) at step 74. A fractional distillation
of the IWF is performed at step 73, thereby separating the IWF from
the performance enhancers so that the IWF can be filtered at step
70 and stored at step 71. The performance enhancers are disposed of
at step 69.
[0063] Yet another method is illustrated in FIG. 6 which begins
with the loading of the washing apparatus at step 60. After the
fabric is loaded, the first step in the method is the addition of a
solvent mixture comprising the IWF and a hydrophobic solvent at
step 75. The hydrophobic solvent is responsible for removing oily
soils and oil-based stains. The fabric load is tumbled for
approximately 2-5 minutes at step 76. A combination drain and soft
spin step is carried out at step 77 whereby the vast majority of
the IWF and hydrophobic solvent mixture is collected at a
separation and recovery center at step 78 where a gravity
separation is carried out. Because the IWF is substantially heavier
than the hydrophobic solvent, the two liquids are easily separated.
The IWF is filtered at step 79 and stored at step 80. The
hydrophobic solvent is filtered and stored at step 81. After the
IWF and hydrophobic solvent are drained away from the fabric at
step 77, a hydrophilic solvent is added at step 82 to remove water
soluble material and particulates. A combination of the hydrophilic
solvent and fabrics are tumbled for a time period ranging between 2
and 5 minutes at step 83. A combination drain and soft spin step is
carried out at step 84. The bulk of the hydrophilic solvent is
captured at step 85. Air is introduced into the washing chamber at
step 86 which results in the production of solvent vapors which are
condensed at step 87 and combined with the liquid solvent at step
88 where the temperature of the contaminated hydrophilic solvent is
increased to its boiling point before being fractionally distilled
at step 89. Preferably, a coil is used to condense the vapors at
step 87 that has a sufficient length and temperature gradient to
condense all fluids simultaneously. The hydrophilic solvent, less
contaminants, is filtered and stored at step 90 while the
contaminants are disposed of at step 91. It is anticipated that air
introduced into the washing chamber at a rate of approximately 25
cubic feet per minute (CFM) will fully dry the fabric in a time
period ranging from about three (3) minutes to about five (5)
minutes, depending upon the specific hydrophilic solvent
utilized.
[0064] Turning to FIG. 7, an additional method of washing fabric in
accordance with the present invention is illustrated which again
begins with the loading of the machine at step 60. A combination of
IWF and hydrophilic solvent are added to the fabric disposed in the
washing chamber at step 92. The fabric, IWF and hydrophilic solvent
are then tumbled from a time period ranging from two (2) to about
five (5) minutes, and most likely less than ten (10) minutes at
step 93. A combination drain and soft spin process is carried out
at step 94 which results in the collection of the IWF and
hydrophilic solvent at step 95 where a gravity separation is
performed. The hydrophilic solvent is filtered, stored and saved at
step 96. The IWF is filtered at step 97 and stored at step 98 for
re-use with the hydrophilic solvent during the next cycle.
Hydrophobic solvent is then added to the fabric disposed within the
washing chamber at step 99 before a tumbling or agitation step is
carried out at step 100 which, again, lasts from about two (2) to
about five (5) minutes. A combination drain and soft spin step is
carried out at step 101. The hydrophobic solvent is captured at
step 102, mixed with water at step 103 before a gravity separation
is carried out at step 104. The hydrophobic solvent is filtered and
stored for re-use at step 105 while the water and contaminants are
disposed of at step 106. Air is introduced to the washing chamber
at step 107 for drying purposes which will normally take from about
three (3) to about five (5) minutes when the air is introduced at a
rate between about 10 CFM and about 100 CFM.
[0065] Another method of practicing the present invention is
illustrated in FIG. 8 which again begins with the loading of the
machine at step 60. In the method illustrated in FIG. 8, the
washing chamber is pressurized to about 20 psi at step 107. A mist
of IWF solvent is sprayed onto the fabric in the washing chamber at
step 108 while the fabric is being tumbled during the rotation of
the washing chamber. The purpose of adding the IWF in a mist form
is to provide a greater surface area coverage with less IWF volume.
The increase in pressure minimizes the amount of vaporization of
the IWF. The fabric is then subjected to a series of spray jets
which spray IWF onto the fabric at a rate of about 10 ml/s at step
109. The application of the IWF under pressure through the jets at
step 109 helps to dislodge particulates and other insoluble
material from the fabric. Co-solvents are added in a ratio of
approximately 1:1 at step 110 before the combination of the fabric,
IWF and co-solvents are tumbled at step 111 for a time period
ranging from about two (2) minutes to about five (5) minutes. The
pressure is decreased at step 112 and the IWF solvents and
contaminants are drained off and captured at step 113. The
temperature of the mixture is increased at step 114 to the lowest
boiling point, either the IWF or co-solvent, and a fractional
distillation is carried out at step 115. The co-solvent is filtered
and stored at step 116 while the IWF is filtered at step 117 and
stored at step 118. The contaminants are disposed of at step 119.
Air is introduced into the washing chamber at step 120 at about 25
CFM for a time period ranging from about three (3) minutes to about
five (5) minutes for drying purposes.
[0066] Another method of carrying out the present invention is
illustrated in FIG. 9. The fabric or clothes are loaded into the
machine at step 60. The cycle begins with a soft spin of the load
at step 121. IWF and performance enhancers are introduced into the
washing chamber at step 122, preferably through a spray nozzle. The
IWF and performance enhancers are collected and recirculated onto
the fabrics at step 123. The spraying of the IWF and performance
enhancers may last from a time period ranging from about one (1)
minute to about three (3) minutes. Additional IWF is added at step
124 to provide a transport medium for the removal of oils and
particulates. The load is agitated at step 125 for a time period
ranging from about three (3) minutes to about seven (7) minutes. A
combination drain and soft spin procedure is carried out at step
126 and the washing chamber is heated at step 127 to vaporize any
remaining solvent on the fabric. The IWF and solvent is captured
and condensed at step 128, the pressure is decreased at step 129 to
separate the IWF from the performance enhancer. The IWF is
condensed at step 130, filtered at step 131 and stored at step 132.
The performance enhancers and contaminants are disposed of at step
133.
[0067] Another method of practicing the present invention is
illustrated in FIG. 10. The machine is loaded with fabric at step
60. A combination of detergent and water is introduced into the
washing chamber at step 135. The fabric, detergent and water
combination is agitated for a time period ranging from about six
(6) minutes to about eight (8) minutes at step 136. The IWF and at
least one hydrophilic solvent are added at step 137 for removing
the water and transporting the particulates from the load. The IWF
and hydrophilic solvent are miscible prior to the addition,
however, in the presence of water, they become immiscible and
therefore, upon capture of the IWF hydrophilic solvent and water at
step 138, the IWF can be separated using a gravity separation
technique at step 139. The IWF is filtered at step 140 and stored
at step 141 where it is combined with the recovered hydrophilic
solvent. The hydrophilic solvent is recovered by increasing
water/hydrophilic solvent mixture at step 142 to boil off the
hydrophilic solvent at step 143 leaving the water behind. The water
and contaminants are disposed of at step 144. The hydrophilic
solvent is then re-combined with the IWF at step 141.
[0068] Still referring to FIG. 10, ozone or ultraviolet (UV)
radiation is applied to the fabric at step 145 to assist in the
bleaching and/or disinfecting and/or odor removal of the fabric
load. The ozone concentration should be greater than 500 ppm and
the UV wavelength should fall in a range between 160-380 nm. As
indicated at step 146, the load should be tumbling during the
application of the ozone and/or UV. Air is then introduced for
drying purposes at step 147.
[0069] Another method of practicing the present invention is
illustrated in FIG. 11. The fabric load, or clothing, is hung at
step 150 within a sealed chamber. Performance enhancers are
"fogged" into the chamber in a volume weight about equal to that of
the fabric load at step 151. Instead of a typical agitation
process, the clothing is shaken or vibrated for a time period
ranging from about three (3) minutes to about five (5) minutes.
Ozone and/or UV may be applied to the clothing in appropriate
amounts for stain removal and/or odor control at step 153. IWF is
introduced into the vessel or cabinet at step 154 in a mist form
and in an amount of about 11/3 the weight of the fabric and
performance enhancers. The cabinet temperature is then increased at
step 155 to vaporize the performance enhancers and IWF. The
performance enhancers and IWF mixture is captured at step 156 and
fractionally distilled at step 157. The IWF is filtered at step 158
and stored at step 159. The performance enhancers are disposed of
at step 160.
[0070] Yet another method of practicing the present invention is
illustrated in FIG. 12. The machine is loaded at step 161 and the
vessel pressure is reduced to about 10 psi or below at step 162. As
the IWF is being added at step 163, the temperature of the vessel
is increased to approximately 30.degree. C. which results in a
steaming of the fabric or clothing with the IWF. The IWF vapors are
condensed at step 164 preferably by a condenser disposed at the top
of the machine which then re-introduces the condensed vapors back
into the washing chamber for a time period ranging from about five
(5) minutes to about ten (10) minutes, preferably while the clothes
are being tumbled (see step 165). The clothes are then showered
with a co-solvent at step 166 to remove particulates and oily
soils. The co-solvent, IWF and contaminants are captured at step
167, separated by centrifugal separation at step 168 before the
contaminants are disposed of at step 169. The co-solvent and IWF
are separated at step 170 by gravity separation before the
co-solvent is filtered at step 171. The showering of the co-solvent
onto the garments may be repeated at step 166, several times if
necessary. The IWF is filtered at step 172 and stored at step 173.
The IWF that has been condensed at step 164, may also be captured
at step 174 and filtered by the common filter at step 172 and
stored in the IWF storage vessel at step 173. The temperature of
the vessel or chamber is increased at step 175 to fully dry the
clothing before the pressure is increased to atmospheric pressure
at step 176.
[0071] As noted above, one family of chemicals particularly suited
for use as IWFs in the methods and apparatuses of the present
invention are "fluoroinert" liquids. Fluoroinert liquids have
unusual properties which make them particularly useful as IWFs.
Specifically, the liquids are clear, colorless, odorless and
non-flammable. Fluoroinerts differ from one another primarily in
boiling points and pour points. Boiling points range from a about
56.degree. C. to about 253.degree. C. The pour points typically
range from about 30.degree. C. to about -115.degree. C.
[0072] All of the known fluoroinert liquids possess high densities,
low viscosities, low pour points and low surface tensions.
Specifically, the surface tensions typically range from 12 to 18
dynes/cm.sup.2 as compared to 72 dynes/cm.sup.2 for water.
Fluoroinert liquids typically have a solubility in water ranging
from 7 ppm to 13 ppm. The viscosity of fluoroinerts typically
ranges from 0.4 centistokes to 50 centistokes. Fluoroinerts also
have low KB values, otherwise known as kauri-butanol values. The KB
value is used as a measure of solvent power of hydrocarbon
solvents. Fluoroinerts have little or no solvency.
[0073] In addition to fluoroinerts, hydrofluoroethers,
perfluorocarbons and similarly fluorinated hydrocarbons can be used
as an IWF in the methods and apparatuses of the present invention.
These additional working fluids are suitable due to their low
surface tension, low vapor pressure and high fluid density.
[0074] In the above methods, the cleaning agents or performance
enhancers may be applied to the fabric by way of an immersion
process, misting, foaming, fogging, the application of a gel to the
fabric, or the mixture of a solid powder or solid particulates in
the IWF. The machine loading of the fabrics or clothes may be a
bulk or batch process, a continuous process or, as noted above with
respect to FIG. 11, the clothes may be hung in a sealable
chamber.
[0075] The removal of a film-type soil may be performed by vapor
degreasing, increasing the temperature within the washing chamber,
increasing the pH within the washing chamber, solubilization of the
film-type soil, the application of enzymes to the film-type soil,
the application of performance enhancers that break up the surface
tension of the film-type soil or performance enhancers that
increase the viscosity of the IWF and therefore increase the
effectiveness of mechanical agitation in removing the film-type
soil.
[0076] Methods of removing particulate soil from fabrics in
accordance with the present invention include attacking the soil
with a working fluid having a low surface tension and tumbling or
agitating the working fluid and fabrics. Particulate soil may also
be removed by spraying the fabric with an IWF with a jet spray.
Another effective method of removing particulate soil in accordance
with the present invention includes vibrating or shaking the
fabrics and IWF inside the washing chamber.
[0077] Water soluble stains may be removed in accordance with the
present invention by using water as a co-solvent, using performance
enhancers to increase the solubility of the stain in the IWF,
shifting the pH of the mixture in the washing chamber, shifting the
ionic strength of the mixing chamber and the washing chamber,
increasing or decreasing the conductivity of the mixture in the
washing chamber, and increasing or decreasing the polarity of the
mixture in the washing chamber.
[0078] Stains consisting primarily of protein may be removed in
accordance with the present invention with the use of enzymes,
performance enhancers that cause the protein to swell, performance
enhancers that cleave the protein, soaking the fabric in the
washing chamber in IWF alone or IWF in combination with the
performance enhancer and the use of low temperature tumbling and/or
soaking.
[0079] Stains consisting primarily of carbohydrates may be removed
in accordance with the present invention by hydrating the stain by
using water as a co-solvent, the use of enzymes, a shifting of the
pH in the washing chamber, an increase of the temperature in the
washing chamber and performance enhancers that increase the
solubility of the carbohydrate stain in the IWF and/or co-solvent.
Bleaching strategies may also be employed in accordance with the
present invention. Bleachable stains may be removed by oxidation,
reduction, the use of enzymes, the use of performance enhancers to
cleave color bonds and the pH may also be shifted within the
washing chamber to remove a bleachable stain.
[0080] Surfactants may be removed from the fabrics in accordance
with the present invention through use of dilution, force
convection, vaporization, a solvent that is miscible with the
surfactant, neutralization or phase inversion techniques.
[0081] As indicated above in FIGS. 4-12, tumbling of the fabric,
IWF and any additives including performance enhancers and
co-solvents in the washing chamber is a suitable method of
transferring mass, i.e. soils, from the fabric to the IWF and/or
co-solvent. Other methods of mass transfer include rinsing,
centrifugation, shaking, wiping, dumping, mixing and wave
generation.
[0082] Also, as indicated above in FIGS. 4-12, the application of
air is a suitable method of dehydration or drying the fabric. Other
methods of drying may employ centrifugation, liquid extraction, the
application of a vacuum, the application of forced heated air, the
application of pressurized air, simply allowing gravity to draw the
IWF away from the fabric and the application of a moisture
absorbing material.
[0083] As indicated above in FIGS. 4-12, the IWF and co-solvents
may be recovered through the use of gravity separation, filtration
and centrifugation. In addition, de-watering, scrubbing,
vaporization, phase inversion and the application of an induced
electrical field may be used in recovery and purification of the
IWF and co-solvents.
[0084] As noted above, the tumbling, agitation or nutation may be
accomplished by generally rotating the washing chamber about a
horizontal axis or about a vertical axis. An example of a washing
apparatus having a generally horizontally disposed axis of rotation
is set forth in U.S. Pat. No. 4,759,202, which is incorporated
herein by reference. One example of a washing apparatus having a
generally vertical axis is set forth in U.S. Pat. No. 5,460,018,
which is also incorporated herein by reference.
[0085] An apparatus that can be used to carry out the method set
forth in FIG. 11 is further illustrated in FIGS. 13 and 14.
Specifically, the apparatus 200 includes a main housing or cabinet
201. The cabinet 201 forms an interior region 202 for hanging
garments 203. The door 204 is equipped with a gasket 205 for
sealing the interface between the door 204 and the main cabinet
201.
[0086] The cabinet 201 includes an upper assembly 206 which can
include a means for shaking or vibrating the garments 203 (see step
152 in FIG. 11) as well as adding ozone/UV or applying a mist to
the garments 203 (see steps 153, 154 in FIG. 11). The cabinet 201
also includes a lower housing assembly 207 which can support a
moisture or misting generator 208 and a heater 209 for increasing
the temperature inside the cabinet 201. The condenser, distillation
apparatus, filter, storage tank and disposal means (see steps
156-160 in FIG. 11) may be attached to the cabinet 201 and housed
in a manner similar to the IWF storage unit shown at 12 in FIGS. 2
and 3.
[0087] From the above description, it is apparent that the objects
of the present invention have been achieved. While only certain
embodiments have been set forth, alternative embodiments and
various modifications will be apparent from the above description
to those skilled in the art. These and other alternatives are
considered equivalents and within the spirit and scope of the
present invention.
* * * * *