U.S. patent application number 11/249297 was filed with the patent office on 2007-04-19 for stain removal process using combination of low and high speed spin.
Invention is credited to Flavio E. Bernardino, Dale Edward Mueller, Mary E. Zeitler.
Application Number | 20070084000 11/249297 |
Document ID | / |
Family ID | 37913469 |
Filed Date | 2007-04-19 |
United States Patent
Application |
20070084000 |
Kind Code |
A1 |
Bernardino; Flavio E. ; et
al. |
April 19, 2007 |
Stain removal process using combination of low and high speed
spin
Abstract
An improved method for treating textiles such as clothing with a
concentrated solutions in an automatic washer by alternating the
speed of rotation of the automatic washer wash basket from a low
spin speed to a high spin speed and applying the concentrated
solution to the textiles when the wash basket is spinning at the
low spin speed.
Inventors: |
Bernardino; Flavio E.; (St.
Joseph, MI) ; Zeitler; Mary E.; (St. Joseph, MI)
; Mueller; Dale Edward; (Benton Harbor, MI) |
Correspondence
Address: |
WHIRLPOOL PATENTS COMPANY - MD 0750
Suite 102
500 Renaissance Drive
St. Joseph
MI
49085
US
|
Family ID: |
37913469 |
Appl. No.: |
11/249297 |
Filed: |
October 13, 2005 |
Current U.S.
Class: |
8/158 ;
8/159 |
Current CPC
Class: |
D06F 39/02 20130101;
D06F 39/088 20130101 |
Class at
Publication: |
008/158 ;
008/159 |
International
Class: |
D06F 35/00 20060101
D06F035/00; D06F 39/00 20060101 D06F039/00 |
Claims
1. A method for laundering a textile wash load in an automatic
washing apparatus comprising the steps of: a. loading a textile
wash load into a wash basket of the automatic washing apparatus
wherein the wash basket is surrounded by a stationary wash tub; b.
introducing a volume of chemical solution into the wash tub; c.
rotating the washer basked relative to the stationary wash tub at a
low spin speed; d. applying at least a portion of the concentrated
chemical solution to the textile wash load while the wash basket in
rotating at a low spin speed; and e. rotating the wash tub at a
high spin speed.
2. The method of claim 1 wherein steps b-e are repeated at least
once.
3. The method of claim 2 wherein steps b-e are repeated a
pre-determined number of times.
4. The method of claim 1 wherein the volume of chemical solution is
introduced into the stationary wash tub without wetting the textile
wash load.
5. The method of claim 1 wherein applying step d is accomplished by
withdrawing chemical solution from the wash tub, and spraying the
withdrawn chemical solution onto the textile wash load.
6. The method of claim 5 wherein essentially all of the chemical
solution is withdrawn from the wash tub and sprayed onto the
textile wash load during step d.
7. The method of claim 1 wherein the low spin speed is a spin speed
that applies less than 1 GPa of centrifugal force on the textile
load.
8. The method of claim 1 wherein the low spin speed is a spin speed
wherein there is essentially no extraction of liquids from the
textile wash load.
9. The method of claim 1 wherein the high spin is a spin speed that
applies more than 1 GPa of centrifugal force on the textile wash
load.
10. The method of claim 1 wherein the high spin speed is a spin
speed that is sufficient to extract at least some interstitial
chemical solution from the textile wash load.
11. The method of claim 1 wherein the chemical solution is a
concentrated chemical solution including a chemical solution and
water.
12. The method of claim 1 wherein the chemical solution is added
directly to the wash tub.
13. The method of claim 1 wherein water is added into the wash tub
following step e.
14. The method of claim 13 wherein water is added to the wash to in
an amount sufficient to raise the level of chemical solution in the
wash tub.
15. The method of claim 14 wherein the water raise is added in an
amount this is sufficient to the level of chemical solution in the
wash tub to a level selected from a predetermined level, a minimum
detectable level, and a variable level wherein the variable level
is established by adding water to the wash tub for a predetermined
period of time.
16. The method of claim 1 wherein the application of chemical
solution is halted while the wash tub is spinning at a high spin
speed in step e.
17. The method of claim 1 wherein the concentrated chemical
solution is applied to the textile wash load by spraying
18. The method of claim 1 wherein application step d is halted and
the wash basket is spun at a low spin speed for a period of time
sufficient to allow at least some of the concentrated chemical
solution to sweep down through the textile wash load.
19. The method of claim 1 wherein the chemical solution is selected
from the group consisting of detergents, textile pre-treatment
solutions, bleaches, or fabric softeners.
20. The method of claim 1 wherein the concentrated chemical
solution is a detergent and the method of laundering is a textile
wash load pretreatment method.
21. The method of claim 1 wherein the concentrated chemical
solution is bleach and the method of laundering is a bleach
treatment method.
22. The method of claim 1 wherein the concentrated chemical
solution is a fabric softener and the method of laundering is a
fabric softening method.
23. A method for laundering a textile wash load in an automatic
washing apparatus comprising the steps of: a. loading a textile
wash load into a wash basket of the automatic washing apparatus
wherein the wash basket is surrounded by a stationary wash tub; b.
introducing a chemical into the wash tub and introducing water into
the wash tub to form a concentrated chemical solution having a
measurable level; c. rotating the wash basket relative to the
stationary wash tub at speed that applies less than 1 GPa
centrifugal force on the textile wash load; d. applying at least a
portion of the concentrated chemical solution to the textile wash
load while the wash basket in rotating at a low spin speed; e.
halting the application of the concentrated chemical solution to
the textile wash load; f. rotating the wash basket at a spin speed
that applies greater than 1 GPa centrifugal force to the textile
wash load; g. halting the rotation of the wash basket at a speed
that applies greater than 1 GPa centrifugal force to the textile
wash load; h. introducing water into the wash tub and admixing the
water with the concentrated chemical solution until there is a
measurable level of concentrated chemical solution in the wash tub;
and i. repeating steps c-e at least once.
24. The method of claim 23 wherein steps c-g are repeated a
predetermined number of times.
25. The method of claim 23 wherein steps c-g are repeat steps until
the textile wash load is saturated with concentrated chemical
solution
26. The method of claim 25 wherein the textile wash load is
saturated with the concentrated chemical solution when essentially
no water needs to be added to wash tub in step f to form a
detectable level.
27. The method of claim 23 wherein the measurable level is a
minimum detectable level.
28. A method for laundering a textile wash load in a washing
apparatus comprising the steps of: a. loading a textile wash load
into a wash basket of the washing apparatus wherein the wash basket
is surrounded by a stationary wash tub; b. introducing a
predetermined volume of concentrated detergent solution into the
stationary wash tub without wetting the textile wash load; c.
rotating the wash basket relative to the stationary wash tub at a
low spin speed for a predetermined length of time; d. applying a
volume of the concentrated detergent solution to the textile wash
load while the wash basket is rotating at a low spin speed by
withdrawing concentrated detergent solution from the wash tub and
directing the withdrawn concentrated detergent solution into the
wash basket and into contact with the textile wash load; e.
interrupting application step d and accelerating the wash basket to
a high spin speed; and f. repeating steps c-e a predetermined
number of times.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention concerns improved methods for treating
clothing articles with chemical solutions using an automatic
washer.
[0003] 2. Description of the Art
[0004] In order to improve the cleaning of clothing articles in
automatic washers, consumers routinely apply cleaning chemicals
such as detergents, bleaches, fabric softeners and cleaning
enhancing chemicals to clothing articles before or after they are
placed into automatic washers. Manufactures of automatic washers
have attempted to improve automatic washing machine convenience and
clothing cleaning performance by incorporating clothing
pretreatment steps into automatic washer processes in order to
eliminate the need for consumers to manually pretreat clothing
articles.
[0005] Stain treatment processes based on spin and spray treatment
of fabrics during the wash cycle are known. There are a number of
commercially available automatic washers that are capable of
pretreating clothing with cleaning chemicals. In general, such
automatic washers attempt to saturate the fabric with a highly
concentrated detergent solution in order to enhance the chemical
removal of stains. This concentrated solution is obtained by
combining a detergent with a smaller volume of water than the
regular is used during wash process.
[0006] A technical hurdle that must be managed when pretreating
fabrics with concentrated detergent solution is the potential risk
of "suds lock". U.S. Pat. Nos. 5,507,053 and 5,219,270 disclose
automatic washers that include stain pretreatment apparatuses or
methods. Methods for dealing with suds lock issues caused by
chemical pretreatment step are disclosed, for example, in U.S. Pat.
Nos. 6,591,439, 6,584,811, 6,393,872, 6,269,666, 4,784,666 and
4,987,627. The specifications of each of these patents are
incorporated herein by reference.
[0007] Despite the variety of automatic washer cleaning chemical
treatment methods and apparatuses currently available, there
remains a need for automatic washers that include features and that
operate in a manner that improve the cleanability of clothing and
textiles.
SUMMARY OF THE INVENTION
[0008] One aspect of this invention are methods for laundering a
textile wash load in a washing apparatus comprising the steps of:
loading a textile wash load into a wash basket of the automatic
washing apparatus wherein the wash basket is surrounded by a
stationary wash tub; introducing a volume of chemical solution into
the wash tub; rotating the washer basked relative to the stationary
wash tub at a low spin speed; applying at least a portion of the
concentrated chemical solution to the textile wash load while the
wash basket in rotating at a low spin speed; and rotating the wash
tub at a high spin speed.
[0009] Another aspect of this invention are methods for laundering
a textile wash load in an automatic washing apparatus comprising
the steps of: (a) loading a textile wash load into a wash basket of
the automatic washing apparatus wherein the wash basket is
surrounded by a stationary wash tub; (b) introducing a chemical
into the wash tub and introducing water into the wash tub to form a
concentrated chemical solution having a measurable level; (c)
rotating the wash basket relative to the stationary wash tub at
speed that applies less than 1 GPa centrifugal force on the textile
wash load; (d) applying at least a portion of the concentrated
chemical solution to the textile wash load while the wash basket in
rotating at a low spin speed; (e) halting the application of the
concentrated chemical solution to the textile wash load; (f)
rotating the wash basket at a spin speed that applies greater than
1 GPa centrifugal force to the textile wash load; (g) halting the
rotation of the wash basket at a speed that applies greater than 1
GPa centrifugal force to the textile wash load; (h) introducing
water into the wash tub and admixing the water with the
concentrated chemical solution until there is a measurable level of
concentrated chemical solution in the wash tub; and (i) repeating
steps c-e at least once.
[0010] In still another aspect, this invention includes methods for
laundering a textile wash load in a washing apparatus comprising
the steps of: (a) loading a textile wash load into a wash basket of
the washing apparatus wherein the wash basket is surrounded by a
stationary wash tub; (b) introducing a predetermined volume of
concentrated detergent solution into the stationary wash tub
without wetting the textile wash load; (c) rotating the wash basket
relative to the stationary wash tub at a low spin speed for a
predetermined length of time; (d) applying a volume of the
concentrated detergent solution to the textile wash load while the
wash basket is rotating at a low spin speed by withdrawing
concentrated detergent solution from the wash tub and directing the
withdrawn concentrated detergent solution into the wash basket and
into contact with the textile wash load; (e) interrupting
application step d and accelerating the wash basket to a high spin
speed; and (f) repeating steps c-e a predetermined number of
times.
DESCRIPTION OF THE FIGURES
[0011] FIG. 1 is a perspective view of a partially cut away
automatic washer that includes features capable of performing
embodiments of methods of this invention;
[0012] FIG. 2 is a diagram of an automatic washer that is useful
for performing embodiments of methods of this invention;
[0013] FIG. 3 is a block diagram of a chemical treatment method
embodiment of this invention;
[0014] FIG. 4 is a block diagram of a chemical treatment method
embodiment of this invention;
[0015] FIG. 5 is a block diagram of final washing step of a method
embodiment of this invention; and
[0016] FIGS. 6A-6C are schematic diagrams of steps of an embodiment
of a chemical treatment method of this invention.
DESCRIPTION OF THE CURRENT EMBODIMENT
[0017] The present invention is directed generally to improved
methods for cleaning textile wash loads in automatic washers. The
methods use a combination of low and high wash basket spin speeds
in order to saturate a textile wash load with a chemical solution
to enhance textile wash load cleanability. The unique processing
embodiments of this invention minimize the liquid volume required
to saturate a textile wash load at a given spin speed and they may
also minimize suds lock and splash risk. The use of a combination
of low and high wash basket spin speeds in the methods of this
invention enables the methods to be practiced using washing
machines including relatively common hardware. Moreover, there is
no need for the washing machine that it is capable of performing
the methods of the invention to include splash shields or a sump.
Nor is there is a need for concise system control of low water
level in the wash tub in washing machines that practice the methods
of this invention.
[0018] The present invention relates to methods for treating
textiles with chemical solutions in an automatic washing machine in
order to improve the washing machine performance--i.e., textile
cleanability. In the methods of this invention, a chemical solution
is intermittently applied to textiles loaded in a washing machine
while the washing machine wash basket rotates alternatively at low
and high spin speeds. Thereafter, the chemical solution may
optionally remain in contact with textile wash load for a period of
time before commencing or recommencing standard textile washing
steps.
[0019] A washing machine 10 is generally shown in FIG. 1. Washing
machine 10 includes a wash tub 12 with a vertical agitator 14
therein, a water supply 15, a power supply (not shown), an
electrically driven motor 16 operably connected via a transmission
20 to the agitator 14 and controls 18 including a presettable
sequential control device 22 for use in selectively operating the
washing machine 10 through a programmed sequence of steps. An
optional water level setting control 18 is provided for use in
conjunction with control device 22. A fully electronic control
having an electronic display (not shown) may be substituted for
control device 22. The control device 22 is mounted to a panel 24
of a console 26 on the washing machine 10. A rotatable and
perforate wash basket 28 is carried within wash tub 12 and has an
opening 36 which is accessible through an openable top lid 30 of
the washer 10.
[0020] A sump hose 40 is fluidly connected to a sump (not shown)
contained in a lower portion of tub 12 for providing a fluid
recirculating source. Recirculating fluid exits the sump via
recirculating spray nozzle hose 48 which is fluidly connected to
recirculating spray nozzle 32. An air dome 50 having a deepfill
pressure sensor or transducer provides a pressure signal indicating
when a minimum detectable amount of liquid is present in wash tub
12.
[0021] As described herein, a pressure sensor may be a pressure
switch having predetermined pressure levels that, within certain
limits, will provide one or more signals to control 22 that a
certain pressure has been achieved. Depending on the presence or
absence of such signals, the control will receive and store or
process such information, as is well known. Alternatively, a
transducer may be used to sense pressure and provide a signal of
varying frequency or voltage to control 22 indicating the pressure
levels detected.
[0022] The process of this invention will be discussed in the
context of its operation in a vertical axis automatic washing
machine as shown in several of the figures. However, the processes
of this invention are equally applicable to horizontal or tilted
axis washing machines. Moreover, the processes of this invention
may be practiced in a variety of machines which may include, for
example, different motor and transmission arrangements, pumps,
recirculation arrangements, agitators, impellers, wash baskets,
wash tubs, or controls so long as the arrangements are capable of
accomplishing the processes of this invention.
[0023] FIG. 2 is a schematic diagram of a washing machine useful
for performing methods of the present invention. Hot water inlet 11
and cold water inlet 13 are controlled by hot water valve 17 and
cold water valve 19, respectively. Valves 17 and 19 are selectably
openable to provide fresh water to feed line 60. A spray nozzle
valve 21 is fluidly connected to feed line 60 for selectably
providing fresh water to tub 12 when desired. This fresh water is
delivered by fresh water spray nozzle 31 via fresh water hose 33.
Valves 17 and 19 are openable individually or together to provide a
mix of hot and cold water to a selected temperature.
[0024] Upon opening one or both of valves 17 and 19, fresh water is
selectably provided to a series of dispenser valves via feed line
60. Valve 62 selectably directs fresh water into detergent
dispenser 63. When fresh water is directed to detergent dispenser
63, it flows through dispenser 63 and into wash tub 12 thereby
bypassing wash basket 28. Valve 64 selectably provides fresh water
to bleach dispenser 65, and valve 66 selectably provides fresh
water to softening agent dispenser 67.
[0025] The washing machine of FIG. 2 further includes a liquid
recirculation system. In order to recirculate liquid, tub sump 41
collects liquid at the bottom of wash tub 12 and is fluidly
connected to pump 23 by sump hose 40. For purposes of this
invention, the term "wash liquid" refers to any liquid that is
recirculated during operation of the washing machine, including,
but not limited to any chemical solution concentrated or otherwise,
rinse solutions, and so forth. Pump 23 is selectably operational to
pump liquid from tub sump 41 via pump outlet hose 25 either to
recirculating hose 27 or drain hose 29 depending on the position of
bidirectional valve 30. Recirculating hose 27 directs recirculating
wash liquid to recirculating spray nozzle 32 via recirculating
spray nozzle hose 48 where it is directed towards the textile wash
load located in wash basket 28.
[0026] Control 22 receives a static pressure signal from deepfill
transducer dome 50 via lines 52 for signaling the level of wash
liquid within wash tub 12 including signaling when a minimum
detectable liquid level is reached, however the invention disclosed
herein may be practiced using a liquid detection device other than
a deepfill pressure dome. Control 22 is further operable to receive
input signals via lines 49, including signals from valves 21, 62,
64 and 66 providing on and off times for these valves.
[0027] FIG. 3 is a block diagram of one process embodiment of this
invention for treating textiles such as clothing in automatic
washing machines with chemical solutions. In initial step 100, a
textile wash load is placed into wash basket 28 of an automatic
washing machine. Next, in step 105, wash tub 12 is filled with a
chemical solution followed by the addition of fresh water into wash
tub 12 in step 110. Wash tub 12 may be filled with the chemical
solution in any manner that directs the chemical solution into wash
tub 12 where it can be applied to the textile wash load with pump
23. In one embodiment, the chemical solution is located in wash tub
12 without contacting the textile wash load. In one method a
chemical solution can be poured into wash basket 28 by the consumer
and it can fall through perforations in wash basket 28 and into
wash tub 12. The fresh water can similarly be directed into wash
basket 28. In another method a chemical solution can be poured into
a chemical dispenser such as detergent dispenser 63 where it can
flow directly into wash tub 12 without contacting the textile wash
load. Fresh water can similarly be added to wash tub 12 though
dispenser 63 by opening valve 62. However, any method known in the
art for placing a chemical solution and fresh water in wash tub 12
may be utilized in this step.
[0028] The term "chemical solution" is used herein to refer to any
type of chemical cleaning solutions that are useful in cleaning
textiles in automatic washing machines. Chemical solutions include,
but are not limited to detergents, textile prewash solutions,
bleaches, fabric softeners and any other known or future discovered
chemicals that are useful in enhancing the cleaning of soiled
textiles. Chemical solutions further include chemicals that are
supplied in liquid form and chemicals that are supplied in dried
form that are subsequently liquefied, suspended or dissolved in a
liquid such as water.
[0029] The term "concentrated chemical solution" as used herein
refers to chemical solutions, such as those described above, in
undiluted form as well as to the chemical solutions that are
diluted with diluents such as water. The term "concentrated
chemical solutions" alternatively refers to chemical solutions that
are used in concentrations that are greater than they would
normally be used in standard textile wash processes.
[0030] When the chemical solution is a detergent, the concentrated
detergent solution will typically include a mixture of water and
detergent in which the detergent is present in an amount ranging
from about 0.5% to about 4% or more by weight. The amount of
detergent present in a concentrated detergent solution may be
greater than about 4 wt %.
[0031] In step 120 of FIG. 3, the wash basket 28 is rotated or spun
in relationship to the stationary wash tub 12 at a low spin speed.
The concentrated chemical solution is applied to the textile wash
load held in wash basket 28 as wash basket 26 is rotating at a low
spin speed. The amount of chemical solution applied to the textile
wash load in step 120 may vary from a fraction of the total amount
available in wash tub 12 up to essentially all of the chemical
solution available in wash tub 12. The amount of chemical solution
applied in step 120 can be controlled in one embodiment, by
applying the chemical solution to the textile wash load using a
pump having a known volumetric feed rate and actuating pump for a
predetermined period of time to apply a pre-calculated volume of
chemical solution to the textile wash load. In another embodiment,
wash tub 12 holds a chemical solution and water to form a
concentrated chemical solution. In this embodiment, wash tub 12
holds a known and predetermined volume of concentrated chemical
solution. Pump 23, which has a known flow rate, is actuated for a
predetermined period of time during which essentially all of the
available concentrated chemical solution is applied to the textile
wash load. Essentially all of the available concentrated chemical
solution refers to the total amount of chemical solution in wash
tub 28 less the amount of concentrated chemical solution that is
necessary to prevent pump 23 from cavitating from losing suction
during the chemical solution application step.
[0032] The concentrated chemical solution may be applied to the
textile wash load by any means known in the art for applying a
liquid to textiles loaded in a wash basket. In one method, the
concentrated chemical solution is directed by pump 23 to nozzles
such as nozzle 32 of FIG. 2 so that the concentrated chemical
solution can be sprayed directly on the textile wash load form a
point above the wash load.
[0033] Wash basket 28 is preferably spun at a low spin speed for a
predetermined period of time in step 120. The term "low spin speed"
refers to a wash basket spin speed at which a chemical solution can
be applied to the textile wash load such that there is essentially
no axial extraction of the chemical solution from the textile wash
load. In yet another embodiment, the low spin speed is a speed that
applies less than one gravity of centrifugal force (less than 1
GPa) to the textile wash load.
[0034] In step 120, wash basket 28 is rotated at a low spin speed
for a period of time. The period of time is generally a
predetermined period of time that is set during the development of
the washing machine and that is integral to the wash machine
control program. In one embodiment of this invention, the
predetermined period of time may change depending upon the
designated textile load size (e.g. small or large), load type (e.g.
delicates or cottons) and/or wash cycle designated by the washing
machine user. The predetermined period of time during which wash
basket 28 is a low spin speed and step 120 will generally range
from a minimum of about 1 to a maximum of about 60 seconds with an
alternative and narrower range of time from about 1 to about 20
seconds. The predetermined period of time can be greater or less
than the values given above depending upon factors such as
recirculation pump flow rate and the ability of pressure transducer
to detect low water level.
[0035] In step 120 of FIG. 3, the application of concentrated
chemical solutions may be interrupted before the wash basket spin
speed is accelerated from a low spin speed to a high spin speed, or
it may be interrupted during the acceleration step or shortly after
the acceleration step is complete. It is preferred that the
application of the concentrated chemical solution to the textile
wash load in step 120 is interrupted before wash basket 28 is
accelerated from a low spin speed to a high spin speed.
[0036] In step 130 of FIG. 3, the application of the concentrated
detergent solution is interrupted and the wash basket spin speed is
increased to a high spin speed where it is maintained for a
predetermined period of time. One purpose of rotating wash basket
28 at a high spin speed is to extract some interstitial chemical
solution from the textile wash load. Moreover, the high spin speed
causes the wash load to move towards the peripheral wall of wash
basket 28 and permits the chemical solution located on the outmost
layer of textiles in the wash basket to migrate into the layers of
the textile wash load closer to the wall of wash basket 28. For
purposes of this invention, the term "high spin speed" means a spin
speed that applies a centrifugal force greater than 1 GPa to the
textile wash load. Alternatively, the term "high spin speed" refers
to a spin speed that causes at least some axial movement of
chemical solutions to the textile wash loads as shown in FIG.
6C.
[0037] The predetermined period of time during which wash basket 28
spins at a high spin speed is generally the time necessary to
achieve one or more of the goals of the high spin speed mentioned
above. In general, the predetermined time during which wash basket
28 spins at a high spin speed will range from about 1 to about 180
seconds or in the alternative in a range of time ranging from about
5 to about 30 seconds. Once the predetermined period of time is
reached, the wash basket spin speed is reduced once again to a low
spin speed in step 140.
[0038] Step 150 of FIG. 3 is an optional step in which the textile
wash load is evaluated to determine whether or not the textile wash
load is saturated with the chemical. Step 150 may be omitted
entirely from the process shown in FIG. 4 in which case steps 110,
120, 130 and 140 would be repeated a predetermined number of times
as shown in step 160 of FIG. 4 regardless of the resulting textile
saturation. The predetermined number of times may be determined and
preprogrammed based upon the user's selection of one or more wash
parameters such as the type textile being washed, the temperature
of the water, load size and so forth. In the embodiment of FIG. 4
where there is no endpoint testing, the loop ends when the last
number of the predetermined number of iterations is complete in
step 160 at which time the washing procedure, shown schematically
in FIG. 5, commences.
[0039] If the process does include an endpoint testing step 150,
then the textile wash load is evaluated for whether or not the
endpoint has been achieved before selecting the subsequent process
step. The endpoint can be evaluated by a variety of methods. For
example, the endpoint can be reached when there is no more
available concentrated detergent solution to apply to the textile
wash load. Alternatively, the endpoint can be evaluated by
measuring process parameters such as wash basket motor load, pump
loads, and so forth to correlate the operational parameters with
the degree of saturation of textile wash load. In FIGS. 3 and 4,
when the endpoint or the proper number of iterations are reached,
then the subsequent exposure and washing steps of FIG. 5 are
commenced. In FIG. 3, if the endpoint is not reached, then steps
110, 120, 130 and 140 are repeated. In FIG. 4, if the iterations
are not complete then steps 110, 120, 130 and 140 are repeated.
[0040] In some instances, the textile wash load may not be
saturated with a chemical solution after the predetermined number
of iterations are complete. Or, in the alternative, none or not
enough of the chemical solution may remain in wash tub 28 to be
applied to the textile wash load even though the predetermined
number of iterations of step 160 has not been met. In second and
subsequent iterations of the low spin speed high spin speed steps
120, 130 and 140, water may be added into wash tub 28 in step 110
to raise the liquid level of the wash tub to at least a minimum
detectable level. Once the at least minimum detectable level of
solutions is reached, water addition to the wash tub is halted and
the chemical solution (now diluted) is applied to the textile wash
load while the wash basket is spinning at low spin speeds in
application step 120 by the methods discussed above.
[0041] In one embodiment of this invention, the chemical solution
is a detergent solution that is used to pretreat textiles in order
to improve their cleanability during normal washing procedures. In
this embodiment, once the textile wash load is tested and
determined to be saturated, or once the predetermined number of
iterations of steps 120, 130 and 140 are reached in step 160 of
FIG. 4, the steps shown in FIG. 5 are commenced.
[0042] In step 240 of FIG. 5, the textile wash load is allowed to
remain in contact with the detergent solution for a predetermined
exposure time. During this exposure time, the textile wash load is
exposed to the chemical solution which interacts with stains and
dirt in textile wash load. The exposure time has the effect of
pretreating the stains and dirt in the textile wash load to
facilitate their removal in subsequent washing steps. This is
similar to applying pretreatment cleaning solutions to textiles
before they are loaded into automatic washers. However, in the case
of the present invention, the automatic washer itself performs the
textile pretreatment without human intervention. The predetermined
exposure time will generally range from about 1 to about 15
minutes. The wash basket including the textile wash load will
generally remain at rest during step 240. However, wash basket 28
may optionally spin at low or high spin speeds either continuously
or intermittently during this exposure time.
[0043] Once the predetermined exposure time duration has been
reached, a predetermined volume of fresh water is introduced into
the wash bucket in step 250. The predetermined volume of fresh
water will be of volume that is sufficient to fill wash tub 12 with
enough water so that the textile wash load can be agitated in a
water filed automatic washer in a normal washing process. The
pretreated textile wash load is agitated for a predetermined period
of time in step 260 after which the detergent solution is rinsed
from the load in step 270 to complete the pretreatment and textile
wash steps.
[0044] FIGS. 6A-6C are schematic diagrams of several steps of a
process embodiment of the present invention. In FIG. 6A, a textile
wash load is located in a perforated wash basket 28 associated with
a wash tub 12. A chemical product is directed into the wash tub via
dispenser 170. The washing apparatus may include one or more
dispensers for the addition of chemicals into the washing machine.
Water is then directed through dispenser 170 into wash tub 12 to
fill wash tub 12 to a minimum detectable level. The "minimum
detectable level" is preferably detected using a pressure
transducer and it is defined as the minimum level of liquid in the
wash tub that the transducer can detect. When the minimum
detectable level is detected, a valve that allows for the addition
of water into dispenser 170 is closed.
[0045] In FIG. 6B, the wash basket 28 is spun at a low spin speed
of approximately 25 rpm for a wash basket having a diameter of
about 500 mm. Chemical solution is pumped by a pump 23 from wash
tub 12 through a conduit 172 and out a spray nozzle 176 which
directs the solution at the textile wash load. The low spin speed
is insufficient to force the chemical solution axially to the
textile wash load so the solution permeates the textile wash load
by gravity as shown in lines 179 of FIG. 6B. The chemical solution
is recirculated and applied to the textile wash load for a
predefined time that will not cause pump cavitation. The predefined
time is premised upon knowing the volume of liquid necessary for
the transducer to detect a minimum detectable level of the wash tub
and also knowing the pump flow rate and the amount of volume of
liquid that needs to remain in wash tub 12 in order to prevent pump
cavitation.
[0046] In FIG. 6C, the spraying of the chemical solution onto the
textile wash load is halted and wash basket 28 is spun at a high
spin speed of about 280 rpm. The high spin speed causes at least a
portion of the chemical solution to migrate axially through the
textile wash load as shown in lines 178 of FIG. 6C. In most
instances--depending on the size of the textile wash load--some of
the chemical solution will disengage from the textile wash load and
migrate back into wash tub 28. The steps shown in FIGS. 6A-6C may
be repeated several times. In subsequent steps, additional
chemicals and or water may be added into the wash tub. However, in
most process embodiments only fresh water will be added into wash
tub 28 to raise the wash tub water level of at least a minimum
detectable level 180.
EXAMPLE 1
[0047] Table 1, below, summarizes the steps of a detergent
pretreatment process. Table 2, below, summarizes the steps of a
concentrated bleach treatment process.
[0048] In the stain removal pretreatment process of Table 1, the
manufacturer's recommended amount of powdered or liquid detergent
is added to the wash tub of the automatic washer via the detergent
dispenser. Warm tap water is added to the wash tub through the main
wash dispenser in step 3. The steps 1-13 of Table 1 embody a
concentrated detergent stain removal pretreatment process of this
invention. TABLE-US-00001 TABLE 1 Description Drive of Motor Drive
Motor Step Sequence Notes Action Profile Duration (Min:Sec) 1 coast
wait OFF speed = 0 2 spin ON spin speed = 20; ramp = 30 3 fill WL =
15 mm OFF 4 recirc ON spin 0:15 1 recirc OFF spin 0:20 6 spin ON
spin speed = 100; ramp = 7 0:20 7 spin ON spin speed = 140; ramp =
80 0:15 8 spin ON spin speed = 190; ramp = 90 0:15 9 spin ON spin
speed = 280; ramp = 90 0:25 10 coast OFF 11 spin ON LOOP: go spin
speed = 20; ramp = 30 back to step #3; repeat loop 3-11 5 times
then go to step 12 12 spin OFF OFF 13 coast OFF
[0049] Table 2 summarizes the steps that occur during a
concentrated bleach treatment process embodiment of this invention.
The concentrated bleach treatment process is activated when the
user of the automatic washing machine selects "whites" as the
textile type on the control panel of an automatic washing machine.
The manufacturer's recommended amount of bleach is added to the
wash tub via the bleach dispenser. The concentrated bleach
treatment process is performed following the main wash step in a
standard washing machine. TABLE-US-00002 TABLE 2 Description Drive
of Water Motor Drive Motor Duration Step Sequence Notes Temp
Dispenser Action Profile (Min:Sec) 1 coast wait OFF speed = 0 2
timed fill tap bleach OFF 0:05 cold 3 pause 0:30 4 spin ON spin
speed = 20; 0:05 ramp = 30 5 Fill fill up to ATC fresh WL = 15 mm
hot water nozzle 6 Recirc ON Refill wash ATC fresh spin 1:30 tub to
hot water minimal nozzle detectable level if the WL in the wash tub
drops below 15 mm (the minimum detectable level) within specified
recirc. time 7 Recirc spin OFF 8 Drain ON spin 0:05 9 spin ON spin
speed = 100; 0:20 ramp = 7 10 spin ON spin speed = 140; 0.10 ramp =
80 11 Drain OFF spin 0:05 12 Drain ON spin 13 spin ON spin speed =
190; 0:15 ramp = 90 14 spin ON spin speed = 280; 0:25 ramp = 90 15
spin ON spin speed = 530; 0:05 ramp = 40 16 Drain OFF spin 0:05 17
Drain ON spin 1:20 18 coast OFF 19 Drain OFF OFF
[0050] In Table 1 and/or Table 2: "WL" refers to water level
wherein a water level of 15 mm refers to a height of 15 mm above
the pressure dome which is set as the minimal detectable water
level by the location of the pressure transducer; "ramp" refers to
the time, in milliseconds, for the wash basket to accelerate to the
identified "speed" or rpm; "recirc" indicates whether or not the
recirculation pump that directs fluid from the wash tub sump
through the recirculation line and to a spray nozzle directed at
the textile wash load is off or on; "Coast" refers to the wash
basket spinning on its own momentum without mechanical or
electrical assistance; "Spin ON" or "spin OFF" refers to instances
where the wash basket drive motor is activated "ON" to cause the
wash basket to spin or deactivated "OFF"; "timed fill" refers to a
step where a timed amount of water is added to the wash tub wherein
the time identified is the time that the valve allowing fresh water
to enter the wash tub is open. "ATC hot" refers to hot water having
a temperature that is controlled automatically by the washer by
controlling the amount of fresh hot and cold tap water that is
allowed to enter the wash tub; "drain ON" or "drain OFF" refers to
the valve to the drain being activated "ON" to direct fluid in the
recirculation line to the drain, or "OFF" to close the valve
leading to the drain.
[0051] These inventions disclosed herein may be embodied in other
specific forms without departing from their spirit or essential
characteristics. The described embodiments are to be considered in
all respects only as illustrative and not restrictive. The scope of
the invention is therefore indicated by the appended claims rather
than the foregoing description. All changes within the meaning and
range of equivalency of the claims are to be embraced within that
scope.
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