U.S. patent application number 14/468878 was filed with the patent office on 2016-03-03 for laundry treating appliance and method of control.
This patent application is currently assigned to WHIRLPOOL CORPORATION. The applicant listed for this patent is WHIRLPOOL CORPORATION. Invention is credited to GERSON EGUNI, KAUSTAV GHOSH, WILLIAM L. MURCH, MIR A. QUDDUS.
Application Number | 20160060800 14/468878 |
Document ID | / |
Family ID | 55401832 |
Filed Date | 2016-03-03 |
United States Patent
Application |
20160060800 |
Kind Code |
A1 |
GHOSH; KAUSTAV ; et
al. |
March 3, 2016 |
LAUNDRY TREATING APPLIANCE AND METHOD OF CONTROL
Abstract
A cycle of operation for a laundry treating appliance having a
tub and a rotatable, perforated drum located within the tub and
operably coupled with a motor for rotating the drum, the drum at
least partially defining a treating chamber for receiving laundry
for treatment according to a cycle of operation, the cycle of
operation comprising an anti-stain setting phase and a pre-wash
phase.
Inventors: |
GHOSH; KAUSTAV; (BENTON
HARBOR, MI) ; MURCH; WILLIAM L.; (SAINT JOSEPH,
MI) ; QUDDUS; MIR A.; (SAINT JOSEPH, MI) ;
EGUNI; GERSON; (Campinas-SP, BR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
WHIRLPOOL CORPORATION |
Benton Harbor |
MI |
US |
|
|
Assignee: |
WHIRLPOOL CORPORATION
Benton Harbor
MI
|
Family ID: |
55401832 |
Appl. No.: |
14/468878 |
Filed: |
August 26, 2014 |
Current U.S.
Class: |
8/137 ;
68/12.23 |
Current CPC
Class: |
D06F 2202/08 20130101;
D06F 33/00 20130101; D06F 39/083 20130101; D06F 2220/00 20130101;
D06F 2202/04 20130101; D06F 39/04 20130101; D06F 2204/02 20130101;
D06F 39/02 20130101; D06F 2204/084 20130101; D06F 35/006 20130101;
D06F 2204/04 20130101; D06F 2204/088 20130101; D06F 39/088
20130101 |
International
Class: |
D06F 33/02 20060101
D06F033/02; D06F 39/04 20060101 D06F039/04; D06F 39/08 20060101
D06F039/08 |
Claims
1. A cycle of operation for a laundry treating appliance having a
tub and a rotatable, perforated drum located within the tub and
operably coupled with a motor for rotating the drum, the drum at
least partially defining a treating chamber for receiving laundry
for treatment according to a cycle of operation, the cycle of
operation comprising: a pre-wash phase comprising: forming a hot
pre-wash liquid comprising a mixture of water and treating
chemistry; and supplying the hot pre-wash liquid to the treating
chamber; and an anti-stain-setting phase, prior to the pre-wash
phase, comprising: forming a cold wash liquid comprising water; and
supplying the cold wash liquid to the treating chamber.
2. The cycle of operation of claim 1 wherein the hot pre-wash
liquid comprises a detergent.
3. The cycle of operation of claim 2, further comprising a main
wash phase, subsequent to the pre-wash phase, comprising adding
liquid to the hot pre-wash liquid to form a main wash liquid.
4. The cycle of operation of claim 3 wherein a concentration of the
detergent in the pre-wash liquid is between 1.5 times and 4.5 times
a concentration of the detergent in the main wash liquid.
5. The cycle of operation of claim 3 wherein the hot pre-wash
liquid has a first temperature and the main wash liquid has a
second temperature, lower than the first temperature.
6. The cycle of operation of claim 1 wherein the forming the hot
pre-wash liquid comprises supplying liquid to the tub until a
temperature of the hot pre-wash liquid satisfies a first
temperature threshold.
7. The cycle of operation of claim 6 wherein the first temperature
threshold is in the range of 95-115.degree. F.
8. The cycle of operation of claim 6 wherein the supplying liquid
to the tub comprises supplying hot water from a hot water supply
until the first temperature threshold is satisfied.
9. The cycle of operation of claim 8 further comprising supplying
the hot water to a predetermined fill level and determining if the
hot water satisfies a second temperature threshold.
10. The cycle of operation of claim 9 wherein when the second
temperature threshold is not satisfied, the supplied hot water is
drained and the supplying the hot water and determining if the hot
water satisfies the second temperature threshold is repeated.
11. The cycle of operation of claim 10 wherein when the second
temperature threshold is satisfied, the supplying the hot water
continues until the first temperature threshold is satisfied.
12. The cycle of operation of claim 6 wherein the forming the hot
pre-wash liquid comprises heating liquid in the tub with a heating
element until the first temperature threshold is satisfied.
13. The cycle of operation of claim 1 wherein the forming the hot
pre-wash liquid comprises supplying liquid to the tub until a
predetermined liquid-to-laundry ratio is satisfied.
14. The cycle of operation of claim 13 wherein the predetermined
liquid-to-laundry ratio is about 5 or less.
15. The cycle of operation of claim 1 wherein the forming the hot
pre-wash liquid comprises supplying liquid to the tub such that the
liquid bypasses the laundry.
16. The cycle of operation of claim 15, further comprising rotating
the drum to impart a centrifugal force to the laundry sufficient to
distribute the laundry about a periphery of the drum to form an
annulus of laundry within the treating chamber and supplying the
liquid through a center of the annulus of laundry such that the
treating chemistry bypasses the laundry and flows through the
perforations in the drum into the tub.
17. The cycle of operation of claim 15 wherein the liquid is
supplied directly to the tub.
18. The cycle of operation of claim 1 wherein the forming the cold
wash liquid comprises supplying water from a cold water supply.
19. The cycle of operation of claim 1 wherein the laundry is
treated with the hot pre-wash liquid for between 2 and 10
minutes.
20. The cycle of operation of claim 19 wherein treating the laundry
with the hot pre-wash liquid comprises rotating the drum, actuating
an agitator, recirculating the wash liquid or combinations
thereof.
21. A laundry treating appliance for treating laundry according to
a cycle of operation, comprising: a tub defining a tub interior; a
rotatable, perforated drum located within the tub interior and at
least partially defining a treating chamber for receiving laundry
for treatment; a liquid supply system supplying liquid to the tub
comprising a cold water supply; a recirculation system supplying
liquid in the tub to the treating chamber; and a controller having
control software programmed to: implement a pre-wash phase
comprising: controlling the liquid supply system to supply liquid
to the tub to form a hot pre-wash liquid comprising a mixture of
water and treating chemistry; and controlling the recirculation
system to supply the hot pre-wash liquid to the treating chamber;
and implement an anti-stain-setting phase, prior to the pre-wash
phase, comprising: controlling the cold water supply to form a cold
wash liquid comprising cold water without detergent; and
controlling the liquid supply system or the recirculation system to
supply the cold wash liquid to the treating chamber.
22. The laundry treating appliance of claim 21, further comprising
a dispensing system supplying a treating chemistry to the treating
chamber, wherein the controller is configured to control the
dispensing system to supply a detergent composition to the hot
pre-wash liquid.
23. The laundry treating appliance of claim 22, further comprising
implementing a main wash phase, subsequent to the pre-wash phase,
comprising controlling the liquid supply system to supply liquid to
the hot pre-wash liquid to form a main wash liquid.
24. The laundry treating appliance of claim 23 wherein a
concentration of the detergent in the hot pre-wash liquid is
between 1.5 times and 4.5 times a concentration of the detergent in
the main wash liquid.
25. The laundry treating appliance of claim 21 wherein the
controlling the liquid supply system to form the hot pre-wash
liquid comprises supplying liquid to the tub until a temperature of
the pre-wash liquid satisfies a first temperature threshold.
26. The laundry treating appliance of claim 25 wherein the first
temperature threshold is in the range of 95-115.degree. F.
27. The laundry treating appliance of claim 25 wherein the liquid
supply system further comprises a hot water supply and the
controller is configured to control the hot water supply to supply
hot water to the tub until the first temperature threshold is
satisfied.
28. The laundry treating appliance of claim 27 wherein the
controller is configured to control the hot water supply to supply
hot water to a predetermined fill level and further wherein the
controller is configured to determine if the hot water satisfies a
second temperature threshold.
29. The laundry treating appliance of claim 28 wherein when the
second temperature threshold is not satisfied, the controller is
configured to control a drain to drain the supplied hot water from
the tub and the controller is configured to control the hot water
supply to repeat supplying the hot water and determining if the hot
water satisfies the second temperature threshold.
30. The laundry treating appliance of claim 29 wherein when the
second temperature threshold is satisfied, the controller is
configured to control the hot water supply to continue supplying
the hot water to the tub until the first temperature threshold is
satisfied.
31. The laundry treating appliance of claim 25 further comprising a
heating element, wherein the controller is configured to control
the heating element to heat the liquid in the tub until the first
temperature threshold is satisfied.
32. The laundry treating appliance of claim 21 wherein the
controlling the liquid supply system to form the hot pre-wash
liquid comprises supplying liquid to the tub until a predetermined
liquid-to-laundry ratio is satisfied.
33. The laundry treating appliance of claim 32 wherein the
predetermined liquid-to-laundry ratio is about 5 or less.
34. The laundry treating appliance of claim 21 wherein the laundry
is treated with the hot pre-wash liquid for between 2 and 10
minutes.
35. The laundry treating appliance of claim 21, further comprising
a motor operably coupled to the drum to effect a rotation of the
drum, wherein the controller is configured to control the motor to
rotate the drum to impart a centrifugal force to the laundry
sufficient to distribute the laundry about a periphery of the drum
to form an annulus of laundry within the treating chamber and
wherein the liquid supply system is controlled to supply liquid
through a center of the annulus of laundry such that the treating
chemistry bypasses the laundry and flows through the perforations
in the drum into the tub to form the hot pre-wash liquid.
36. The laundry treating appliance of claim 21 wherein the liquid
supply system is configured to supply liquid directly to the tub to
form the hot pre-wash liquid.
Description
BACKGROUND
[0001] Fatty soils such as sweat, body soils, oily soils, and
fat-based greases can be difficult to remove from laundry. The low
wash liquid volume and low wash liquid temperature typically used
in high efficiency washing machines is generally not conducive to
removing these types of fatty soils from laundry. If not removed,
these fatty soils may accumulate on laundry items, eventually
resulting in staining, dinginess and sometimes malodor,
particularly on active or sportswear items. Some detergent
compositions have attempted to address the issue of fatty soil
removal by using an increase in nonionic surfactants, an
optimization of the ratio of anionic to nonionic surfactants, or an
increase in hydrogen peroxide bleach. However, the effectiveness of
these detergent compositions are effected by the parameters of the
cycle of operation in which they are used. Active and sportswear
textile and garment makers have attempted to address this issue
through the use of different textiles and fabric finishes, such as
silver ions, chitosan, or polymer shields. While these finishes may
reduce the issue of malodor generation, they do not inhibit
accumulation of the fatty soils onto the item.
BRIEF SUMMARY
[0002] A laundry treating appliance and cycle of operation for
treating laundry within a laundry appliance that includes a cycle
of operation comprising an anti-stain setting phase and a pre-wash
phase.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] In the drawings:
[0004] FIG. 1 is a schematic cross-sectional view of a laundry
treating appliance according to one embodiment of the
invention.
[0005] FIG. 2 is a schematic view of a controller of the laundry
treating appliance of FIG. 1.
[0006] FIG. 3 is a flow chart illustrating an automatic cycle of
operation according to an embodiment of the invention.
[0007] FIG. 4 is a flow chart illustrating a method for
implementing an automatic cycle of operation according to an
embodiment of the invention.
[0008] FIG. 5 is a flow chart illustrating a method supplying
heating liquid in a laundry treating appliance according to an
embodiment of the invention.
DETAILED DESCRIPTION
[0009] FIG. 1 is a schematic view of an exemplary laundry treating
appliance 10 in the form of a washing machine according to an
embodiment of the invention. While the laundry treating appliance
is illustrated as a vertical axis, top-fill washing machine, the
embodiments of the invention may have applicability in other
laundry treating appliances, non-limiting examples of which include
a horizontal washing machine, a combination laundry treating
appliance and dryer, a non-aqueous laundry treating appliance, or a
tumbling or stationary refreshing/revitalizing machine, for
example.
[0010] The washing machine 10 includes a cabinet or housing 12 and
an imperforate tub 14 that defines an interior 16 of the washing
machine 10. A sump 18 may be in fluid communication with the
interior 16 of the tub 14. A perforated wash basket or drum 20 may
be located within the interior 16 and rotatable relative to the tub
14 and may define a laundry treating chamber 22 for receiving a
laundry load for treatment according to an automatic cycle of
operation. Rotation of the drum 20 may be considered as rotation of
any items located within the treating chamber 22. The drum 20 may
include a plurality of perforations or apertures 24 such that
liquid supplied to the drum 20 may flow through the perforations 24
to the tub 14. An agitator or clothes mover 26 may be located
within the laundry treating chamber 22 and rotatable relative to
and/or with the drum 20. While the embodiments of the invention are
described in the context of a washing machine having a rotatable
drum located within a tub, it will be understood that the
embodiments may also be used in a washing machine which has an
imperforate drum without a tub.
[0011] The drum 20 and/or the clothes mover 26 may be driven by an
electrical motor 28, which may or may not include a gear case,
operably connected to the drum 20 and/or the clothes mover 26. The
clothes mover 26 may be commonly oscillated or rotated about its
axis of rotation during a cycle of operation in order to provide
movement to the load contained within the laundry treating chamber
22. The drum 20 may be rotated at high speed to centrifugally
extract liquid from the load and to discharge the extracted liquid
from the drum 20. The top of the housing 12 may include a
selectively openable lid 30 to provide access into the laundry
treating chamber 22 through an open top of the drum 20.
[0012] The washing machine 10 also includes a liquid supply system
for supplying water to the washing machine 10 for use in the
treatment of laundry during a cycle of operation. The liquid supply
system may include a source of water, such as a household water
supply source 42, which may include separate valves 46, 48 for
controlling the flow of hot and cold water, respectively. Water may
be supplied through an inlet conduit 50 directly to the drum 20 by
controlling a diverter valve 52. The diverter valve 52 may be a
diverter valve having two outlets such that the diverter valve 52
may selectively direct a flow of liquid to one or both of two flow
paths. Water from the household water supply source 42 may flow
through the inlet conduit 50 to the diverter valve 52 which may
direct the flow of liquid to an outlet conduit 54 which may be
provided with a spray nozzle 56 configured to spray the flow of
liquid into the drum 20. In this manner, water from the household
water supply source 42 may be supplied directly to the drum 20.
[0013] The washing machine 10 may also be provided with a
dispensing system for dispensing treating chemistry to the drum 20,
either directly or mixed with water from the liquid supply system,
for use in treating the laundry according to a cycle of operation.
The dispensing system may include a dispenser 60 which may be a
single use dispenser, a bulk dispenser or a combination of a single
use and bulk dispenser. The dispensing system may include a
dispenser which may be a single use dispenser, a bulk dispenser or
a combination of a single use and bulk dispenser. Non-limiting
examples of suitable dispensers are disclosed in U.S. Pat. No.
8,196,441 to Hendrickson et al., issued Jun. 12, 2012, entitled
"Household Cleaning Appliance with a Dispensing System Operable
Between a Single Use Dispensing System and a Bulk Dispensing
System," U.S. Pat. No. 8,388,695 to Hendrickson et al., issued Mar.
5, 2013, entitled "Apparatus and Method for Controlling Laundering
Cycle by Sensing Wash Aid Concentration," U.S. Pat. No. 8,397,328
to Hendrickson et al., issued Mar. 19, 2013, entitled "Apparatus
and Method for Controlling Concentration of Wash Aid in Wash
Liquid," U.S. Pub. No. 2010/0000581 to Doyle et al., filed Jul. 1,
2008, entitled "Water Flow Paths in a Household Cleaning Appliance
with Single Use and Bulk Dispensing," U.S. Pub. No. 2010/0000264 to
Luckman et al., filed Jul. 1, 2008, entitled "Method for Converting
a Household Cleaning Appliance with a Non-Bulk Dispensing System to
a Household Cleaning Appliance with a Bulk Dispensing System," U.S.
Pat. No. 8,397,544 to Hendrickson, issued Mar. 19, 2013, entitled
"Household Cleaning Appliance with a Single Water Flow Path for
Both Non-Bulk and Bulk Dispensing," and U.S. Pat. No. 8,438,881,
issued May 14, 2013, entitled "Method and Apparatus for Dispensing
Treating Chemistry in a Laundry Treating Appliance," which are
herein incorporated by reference in full.
[0014] Regardless of the type of dispenser used, the dispenser 60
may be configured to dispense a treating chemistry directly to the
drum 20 or mixed with water from the liquid supply system through a
dispensing outlet conduit 62. The dispensing outlet conduit 62 may
include a dispensing nozzle 64 configured to dispense the treating
chemistry into the drum 20 in a desired pattern and under a desired
amount of pressure. For example, the dispensing nozzle 64 may be
configured to dispense a flow or stream of treating chemistry into
the drum 20 by gravity, i.e. a non-pressurized stream. Water may be
supplied to the dispenser 60 from the inlet conduit 50 by directing
the diverter valve 52 to direct the flow of water to a dispensing
supply conduit 66.
[0015] The washing machine 10 may also include a recirculation and
drain system for recirculating liquid within the laundry holding
system and draining liquid from the washing machine 10. Liquid
supplied to the drum 20 through outlet conduit 54 and/or the
dispensing supply conduit 66 may flow by gravity to the sump 18
through the perforations 24 provided in the side wall and bottom
wall of the drum 20. The sump 18 may also be formed by a sump
conduit 70 that may fluidly couple the sump 18 to a pump 72. The
pump 72 may have an inlet fluidly coupled to the sump 18 and an
outlet configured to fluidly couple to either or both a household
drain 74, which may drain the liquid from the washing machine 10,
or a recirculation conduit 76, which may terminate at a
recirculation inlet 78 to re-supply the recirculated liquid to the
drum 20. In this configuration, the pump 72 may be used to drain or
recirculate liquid in the sump 18, which is initially sprayed into
the treating chamber 22, flows through the drum 20, and then into
the sump 18. Alternatively, two separate pumps may be used instead
of the single pump as previously described. The recirculation inlet
78 may introduce the liquid into the drum 20 in any suitable
manner, such as by spraying, dripping, or providing a steady flow
of liquid. In this manner, liquid provided to the tub 14, with or
without treating chemistry, may be recirculated into the treating
chamber 22 for treating the laundry within.
[0016] The washing machine 10 may also be provided with a heating
system (not shown) to heat liquid provided to the treating chamber
22. In one example, the heating system can include a heating
element provided in the sump 18 to heat liquid that collects in the
sump 18. Alternatively, the heating system may be in the form of an
in-line heater that heats the liquid as it flows through the liquid
supply, dispensing and/or recirculation systems.
[0017] The liquid supply, dispensing, and recirculation and drain
systems may differ from the configuration shown in FIG. 1, such as
by inclusion of other valves, conduits, treating chemistry
dispensers, sensors, such as water level sensors and temperature
sensors, and the like, to control the flow of liquid through the
washing machine 10 and for the introduction of more than one type
of treating chemistry. For example, the liquid supply system and/or
the dispensing system may be configured to supply liquid into the
interior 16 of the tub 14 such that liquid may be supplied directly
to the tub 14 without having to travel through the drum 20.
[0018] Referring now to FIG. 2, the washing machine 10 also
includes a control system for controlling the operation of the
washing machine 10 to implement one or more cycles of operation.
The control system may include a controller 82 located within the
housing 12 and a user interface 84 that is operably coupled with
the controller 82. The user interface 84 may include one or more
knobs, dials, switches, displays, touch screens and the like for
communicating with the user, such as to receive input and provide
output. The user may enter different types of information
including, without limitation, cycle selection and cycle
parameters, such as cycle options.
[0019] The controller 82 may include the machine controller and any
additional controllers provided for controlling any of the
components of the washing machine 10. For example, the controller
82 may include the machine controller and a motor controller. Many
known types of controllers may be used for the controller 82. The
specific type of controller is not germane to the invention. It is
contemplated that the controller 82 is a microprocessor-based
controller that implements control software and sends/receives one
or more electrical signals to/from each of the various working
components to effect the control software. As an example,
proportional control (P), proportional integral control (PI), and
proportional derivative control (PD), or a combination thereof, a
proportional integral derivative control (PID control), may be used
to control the various components.
[0020] As illustrated in FIG. 2, the controller 82 may be provided
with a memory 88 and a central processing unit (CPU) 90. The memory
88 may be used for storing the control software that is executed by
the CPU 90 in completing a cycle of operation using the washing
machine 10 and any additional software. Examples, without
limitation, of cycles of operation include: wash, heavy duty wash,
delicate wash, quick wash, pre-wash, refresh, rinse only, timed
wash and any of the cycles of operation described herein. The
memory 88 may also be used to store information, such as a database
or table, and to store data received from one or more components of
the washing machine 10 that may be communicably coupled with the
controller 82. The database or table may be used to store the
various operating parameters for the one or more cycles of
operation, including factory default values for the operating
parameters and any adjustments to them by the control system or by
user input.
[0021] The controller 82 may be operably coupled with one or more
components of the washing machine 10 for communicating with and
controlling the operation of the component to complete a cycle of
operation. For example, the controller 82 may be operably coupled
with the motor 28, the pump 72, the dispensing nozzle 64, the
dispenser 60, the valves 46, 48, and 52, and any other additional
components that may be present such as a steam generator, and a
sump heater (not shown) to control the operation of these and other
components to implement one or more of the cycles of operation.
[0022] The controller 82 may also be coupled with one or more
temperature sensors 92 to determine a temperature of the liquid
provided by the water supply source 42, the liquid recirculated by
the recirculation system, a temperature of the treating chamber 22,
a temperature of liquid in the sump 18 and/or the temperature of
the laundry items. The one or more temperature sensors 92 can be
provided in the sump 18 or anywhere along the path of fluid flow
from the water supply source 42 to the inlet conduit 50, outlet
conduit 54 and through the spray nozzle 56, for example. The
controller 82 may also be coupled with one or more additional
sensors 94 provided in one or more of the systems of the washing
machine 10 to receive input from the sensors 94, which are known in
the art and not shown for simplicity. Non-limiting examples of
sensors 94 that may be communicably coupled with the controller 82
include: a moisture sensor, a weight sensor, a chemical sensor, an
optical sensor, a conductivity sensor, a turbidity sensor, a
position sensor and a motor torque sensor, which may be used to
determine a variety of system, laundry and liquid characteristics,
such as laundry load inertia or mass.
[0023] The controller 82 may also be programmed to determine an
amount and/or type of laundry. The amount of laundry may be
qualitative or quantitative and may be determined manually based on
user input through the user interface 84 or automatically by the
washing machine 10 using input provided by one or more sensors
according to a laundry amount determination method. A qualitative
determination of the laundry amount may include determining whether
the laundry is a small, medium or large load. A quantitative
determination may include determining a weight or volume of the
laundry within the treating chamber 22. The type of fabric may be
determined based on user input, such as based on the selected cycle
or one or more selected options, or automatically determined based
on sensor input using any known method. The methods for determining
the amount and/or type of fabric forming the laundry load are not
germane to the embodiments of the invention.
[0024] FIG. 3 illustrates a flow chart of an automatic cycle of
operation 100 for treating laundry in the washing machine 10. The
cycle of operation 100 may be executed by the controller 82 to
automatically implement the cycle of operation in the washing
machine 10. The cycle of operation 100 may be used to treat the
laundry to facilitate the removal of soils from the laundry items,
particularly soils having a fatty component, such as body soils,
sweat, and fat-based greases, using a high temperature, low volume
concentrated treating chemistry pre-wash phase. Fatty soils can be
difficult to remove from laundry items, especially in a high
efficiency washing machine, which typically utilizes cycles having
low liquid volumes and low temperatures. When items having fatty
soils are washed at low liquid temperatures, some fatty soils may
remain as solids, which have high adhesion forces, making the fatty
soils difficult to remove from the item. If not removed from
laundry items, these fatty soils may accumulate over time, which
can result in the formation of stains, a dingy appearance, and even
lead to the generation of odors. The automatic cycle of operation
and methods described herein utilize a high temperature, low liquid
volume, concentrated detergent pre-wash to facilitate lifting fatty
soils from the laundry items. The high temperatures may be selected
to facilitate melting or softening of solid fatty soils to
facilitate lifting of the soils from the laundry items by the
concentrated detergent.
[0025] The automatic cycle of operation and methods described
herein also utilize an initial cold liquid treatment prior to the
pre-wash phase to minimize the setting of protein-based stains.
Applicants have found that while the high liquid temperatures
facilitate the removal of fatty soils, those same high liquid
temperatures may set some protein-based soils, such as blood, for
example, resulting in the formation of protein-based stains that
are difficult, if not impossible to remove without damaging the
laundry item. Thus, the cycle of operation and methods described
herein include an initial anti-stain setting phase prior to
treatment of the laundry at high temperatures in the hot pre-wash
phase to minimize setting protein-based soils, while still
facilitating the removal of fatty-based soils from the laundry.
[0026] As used herein, a pre-wash phase refers to a phase, prior to
the main wash phase, in which the laundry is treated with a
treating chemistry according to different operating parameters than
the main wash phase. Non-limiting examples of operating parameters
that may vary between the pre-wash phase and the main wash phase
include a temperature of the wash liquid, a concentration of a
treating chemistry in the wash liquid, a volume of the wash liquid,
a duration of the phase, an amount and/or type of mechanical energy
imparted to the laundry, and combinations thereof. In the exemplary
cycle described below, the pre-wash phase is implemented using a
higher temperature wash liquid, a higher concentration of treating
chemistry, a lower volume of wash liquid than the main wash phase.
In addition an amount of mechanical energy imparted during the
pre-wash phase may be lower than that imparted during the main wash
phase, as well as the manner in which the mechanical energy is
imparted may differ between the pre-wash and main phases. For
example, mechanical energy may be imparted to the load by rotating
the drum 20 according to a predetermined rotation profile,
actuating the clothes mover 26, and/or recirculation the
liquid.
[0027] The sequence of steps depicted for the cycle of operation
and the subsequent methods are for illustrative purposes only, and
are not meant to limit any of the cycles or methods in any way as
it is understood that the steps may proceed in a different logical
order or additional or intervening steps may be included without
detracting from the invention.
[0028] The cycle of operation 100 begins with assuming that a user
has placed laundry items for treatment into the drum 20 and
selected the cycle of operation. The cycle of operation 100 may
begin at 101 with an anti-stain setting phase in which the laundry
is treated with cold water that does not include detergent. The
cycle of operation 100 then proceeds to a pre-wash phase 102 in
which the laundry is treated with a low volume of a hot pre-wash
liquid that includes a detergent composition that includes at least
one detergent at a higher concentration than used in a main wash
phase 104. At 104, additional water from the water supply source 42
is supplied to the tub 14 to increase the volume of wash liquid to
a main wash fill level and to decrease the concentration of the
detergent composition to a main wash phase concentration to form a
main wash liquid. The main wash phase 104 may also include
treatment of the laundry with additional treating chemistries. An
extraction and/or drain phase may be implemented at 106 in which
wash liquid collected in the sump 18 is drained from the treating
chamber 22 and an optional extraction phase in which the laundry is
rotated to facilitate the extraction of liquid from the laundry,
which may subsequently be drained from the sump 18. A rinse phase
in which fresh liquid from the water supply source 42 is supplied
to the laundry, and optionally recirculated onto the laundry, one
or more times, may be implemented at 108 to remove the wash liquid
and soil/debris from the laundry. The rinse phase 108 may also
include treatment of the laundry with additional treating
chemistries, such as a rinse aid or fabric softener, for example.
An additional extraction and/or drain phase 110 may be implemented
prior to completing the cycle at 112.
[0029] The amount of liquid supplied to the washing machine 10
during any of the anti-stain setting phase 101, pre-wash phase 102
and the main wash phase 104 may be determined according to any
suitable method and the method used during one of the phases 101,
102 and 104 may be different than the method used during the other
phases. In one example, the amount of supplied liquid may be
determined using one or more liquid level sensors provided in the
tub 14 and/or sump 18. Non-limiting examples of liquid level
sensors include pressure sensors and optical sensors.
[0030] Alternatively, the amount of supplied liquid may be
determined according to a time-based method based on an amount of
time the hot or cold water valves 46 and 48 are open and a flow
rate of water supplied from each. The washing machine 10 may be
provided with a liquid flow sensor that is operably coupled with
the controller 82 to provide flow rate information to the
controller 82 for determining an amount of liquid supplied based on
the amount of time the hot or cold water valves 46, 48 are open. In
another example, the washing machine 10 may be provided with a flow
rate limiter that limits the flow of water from the water supply
source 42 to a predetermined flow rate. The controller 82 may then
use this predetermined flow rate and the amount of time the hot or
cold water valves 46, 48 are open to determine the amount of liquid
supplied.
[0031] A time-based method for determining an amount of supplied
liquid may be particularly useful during phases in which the amount
of liquid supplied may not be sufficient for use with a liquid
level sensor provided in the tub/sump area. For example, the
anti-stain setting phase 101 uses low liquid volumes which may not
be sufficient for measurement using a traditional liquid level
pressure sensor in the sump. In washing machines in which the
liquid is supplied directly to the treating chamber rather than
into the tub, the supplied liquid during the low volume anti-stain
setting phase 101 may be completely absorbed by the laundry and
little to no liquid may collect in the sump.
[0032] In an exemplary embodiment, the cycle of operation 100
corresponds to an active or sportswear cycle. The user interface 84
may be configured to provide the user with the ability to select
the active or sportswear cycle. Active or sportswear typically
include instructions to wash the items in cold or warm water. In
the exemplary embodiment, when the active or sportswear cycle is
selected by the user, the main wash phase 104 may be configured to
wash the laundry in cold or warm water and automatically treat the
laundry according to anti-stain setting phase 101 and pre-wash
phase 102.
[0033] FIG. 4 illustrates an exemplary method 200 for implementing
the cycle of operation 100 of FIG. 3. The anti-stain setting phase
101 includes forming a predetermined amount of an anti-stain
setting liquid in the form of a cold wash liquid comprising cold
water. While the embodiments of the invention will be described in
the context of an anti-stain setting liquid that does not include a
detergent, it will be understood that the anti-stain setting liquid
may include any desired treating chemistry. As used herein, cold
liquid refers to water or a mixture of water and a treating
chemistry in which the water is supplied from the water supply
source 42 and has not been heated by an internal heating system
within the washing machine 10 or by an external heating system,
such as a household water heater. Hot liquid, as used herein,
refers to water, which may optionally include one or more treating
chemistries, that has been heated to at least 95.degree. F. by an
internal heating system within the washing machine 10 or by an
external heating system, such as a household water heater.
Typically, the cold anti-stain setting liquid includes water
supplied by the cold water valve 48 of the water supply source 42,
which in a preferred embodiment does not include an additional
treating chemistry. The exact temperature of the anti-stain setting
liquid will vary depending on the source of water supplying the
water supply source 42 and the environment in which the water
supply source 42 is located.
[0034] The predetermined amount of anti-stain setting liquid formed
at 202 may be an amount which wets or dampens the laundry load
without overly saturating the load and may be based on an amount
and/or type of fabric forming the laundry load, characteristics of
the specific washing machine implementing the cycle, and/or a
predetermined time period. Adding too much cold liquid at 202 may
increase the amount of hot liquid needed to reach the desired
temperature in the next stage in the cycle, which may undesirably
increase the length of the cycle. The amount of anti-stain setting
liquid may be determined by the controller 82 using pre-programmed
algorithms or stored look-up tables relating the amount of
anti-stain setting liquid to one or more characteristics of the
laundry, such as an amount of fabric type, the selected cycle of
operation, and/or the specific machine implementing the cycle.
Generally, the amount of anti-stain setting liquid supplied at 202
is in the range of 2-8 liters, and may vary depending on the type
and/or amount of laundry and characteristics of the washing
machine, such as the dimensions of the tub, drum and/or sump. An
illustrative amount of anti-stain setting liquid for a 3.6 kg
standard 100% cotton load is 4 liters of cold water. The standard
load is based on the standards set forth in the Association of Home
Appliance Manufacturers (AHAM) "Performance Evaluation Procedures
for Household Clothes Washers" AHAM HLW-1-2010.
[0035] In one example, the volume of anti-stain setting liquid may
be based on satisfying a predetermined liquid to laundry ratio
(e.g. kilograms of liquid per kilogram of laundry). As used herein,
liquid to laundry ratio refers to the ratio of all the liquid in
the washing machine (including free liquid in the drum 20, liquid
absorbed by the laundry, and free liquid within the tub 14 and sump
18) to the total laundry amount. For example, the anti-stain
setting liquid may be supplied to provide a liquid to laundry ratio
in the range of 0.5-2.2. The amount of anti-stain setting liquid
may be determined by the controller 82 using pre-programmed
algorithms or stored look-up tables relating an amount of laundry
to an amount of anti-stain setting liquid based on satisfying a
predetermined liquid to laundry ratio.
[0036] Alternatively, the amount of anti-stain setting liquid may
correspond to a predetermined default amount. For example, the
default amount may correspond to an amount that is sufficient to
wet an average load for a particular machine and/or cycle. The
default amount may be determined empirically based on average load
size and an amount of anti-stain setting liquid that provides the
desired anti-stain setting properties a predetermined proportion of
the time (e.g. 75% of the time).
[0037] The temperature of the cold anti-stain setting liquid formed
at 202 may be within a range of 60-86.degree. F. As of the filing
of this application, the United States Federal Trade Commission
defines "cold water" as used for fabric care labels as having a
temperature less than 86.degree. F. In a preferred embodiment, the
anti-stain setting liquid may be within a range of about
60-80.degree. F. and more preferably about 60.degree. F.
[0038] At 204, the cold anti-stain setting liquid can be supplied
directly to the laundry through the spray nozzle 56 and may
optionally be recirculated onto the laundry to facilitate evenly
wetting the laundry. The drum 20 may be rotated to and the clothes
mover 26 may optionally be activated to agitate the laundry to
facilitate evenly wetting the laundry. In an exemplary cycle, the
drum 20 may be rotated at low speed, e.g. 0-40 rpm, to distribute
the anti-stain setting liquid onto the laundry. In another example,
the motor 28 may be alternately turned "on" and "off" to facilitate
uniform wetting of the laundry.
[0039] An optional extraction and/or drain stage may be implemented
during the transition from the anti-stain setting phase 101 to the
pre-wash phase 102 to extract and/or drain any liquid that may have
collected in the sump 18 during the supply of cold anti-stain
setting liquid to the laundry at 202. Typically, a drain stage will
not be necessary, as the amount of cold liquid is preferably
selected so as to not over saturate the laundry such that liquid
runs off the laundry and collects in the sump 18. Cold liquid
collected within the sump 18 may increase an amount of hot liquid
and/or an amount of time needed to form the hot pre-wash liquid at
the next stage 206, and thus a drain stage may be implemented to
drain any cold liquid from the sump 18.
[0040] Subsequent to the anti-stain setting phase 101, at 206 a hot
pre-wash liquid comprising a mixture of hot water and a detergent
composition is formed. The hot pre-wash liquid may be formed such
that a temperature of the liquid satisfies a first temperature
threshold. Satisfying the first temperature threshold may include
comparing a determined temperature of the pre-wash liquid to a
predetermined reference value that may be a range of reference
values, an upper threshold or a lower threshold stored in the
memory 88 of the controller 82. The term "satisfies" the threshold
is used herein to mean that the variation satisfies the
predetermined threshold, such as being equal to, less than, or
greater than the threshold value. It will be understood that such a
determination may easily be altered to be satisfied by a
positive/negative comparison or a true/false comparison. For
example, a less than threshold value can easily be satisfied by
applying a greater than test when the data is numerically inverted.
The temperature of the pre-wash liquid may be determined using the
temperature sensor 92 which outputs a value indicative of the
temperature of the wash liquid to the controller 82.
[0041] In one example, the first temperature threshold may be
satisfied when the pre-wash liquid temperature is within a range of
95-115.degree. F., inclusive of end points. In another example, the
first temperature threshold may be satisfied when the pre-wash
liquid temperature is at least 98.degree. F. Many of the fatty
soils that may be deposited on laundry, such as sweat, body soils,
and greases, have a melting or softening temperature in the range
of mammalian body temperature of 90-105.degree. F. As described
above, treating the laundry with a pre-wash liquid heated to within
a specific range to melt or soften the fatty soils may facilitate
lifting the soils from the laundry.
[0042] Forming the hot pre-wash liquid at 206 may include
controlling the hot water valve 46 of the water supply source 42 to
supply hot water to the washing machine 10 and/or heating liquid
supplied to the washing machine 10 using an internal heating system
within the washing machine 10. Some washing machines may only be
connected with a supply of cold water and thus an internal heating
system, such as a sump heater, may be used to heat the liquid to
satisfy the first temperature threshold. Alternatively, some
washing machines may not include an internal heating system and
thus the only source of hot water is an externally heated water
supply. In another example, externally heated water supplied to the
washing machine 10 may further be heated using an internal heating
system to more quickly increase the temperature of the liquid to
satisfy the first temperature threshold. The detergent composition
may be provided at any point before, during or after the
temperature of the water satisfies the first temperature
threshold.
[0043] The volume of hot pre-wash liquid may correspond to a tub
fill level that is less than a tub fill level used during the main
wash phase 104. In this manner the laundry is treated with the
detergent composition at a higher concentration than during the
main wash phase 104. The pre-wash tub fill level may be determined
by the controller 82 using pre-programmed algorithms or stored
look-up tables relating the fill level to one or more
characteristics of the laundry, the selected cycle of operation,
and/or the specific machine implementing the cycle. Generally, the
pre-wash tub fill level is in the range of 8-18 liters, and may
vary depending on the type and/or amount of laundry and
characteristics of the washing machine, such as the dimensions of
the tub, drum and/or sump. An illustrative amount of hot pre-wash
liquid for a 3.6 kg AHAM standard 100% cotton load is 16
liters.
[0044] In one example, the volume of hot pre-wash liquid may be
based on satisfying a predetermined liquid to laundry ratio (e.g.
kilograms of liquid per kilogram of laundry) that corresponds to a
low volume pre-wash fill level. For example, the volume of hot
pre-wash liquid may correspond to a liquid to laundry ratio greater
than 0 and less than or equal to 5, preferably in the range of 2.2
to 5. In another example, the volume of the hot pre-wash liquid may
correspond to a fill level that partially immerses or fully
submerges the laundry. Alternatively, the fill level may correspond
to a level that does not contact the laundry such that the laundry
is only wet by recirculation of the liquid onto the laundry.
[0045] Additionally, or alternatively, the volume of hot pre-wash
liquid may correspond to a volume of liquid which provides a
concentration of the detergent composition within a range of 1.5 to
4.5 times the concentration of the detergent composition during the
main wash phase 104, preferably 1.5 to 2 times the concentration of
the detergent composition during the main wash phase 104. The tub
fill level for the pre-wash phase 102 and/or main wash phase 104
may be based on the load amount and/or type, which may be
determined as described above at 202.
[0046] Additionally, or alternatively, for a washing machine
connected with a supply of externally heated water, the volume of
hot pre-wash liquid may be based on supplying the externally heated
water to the tub 14 until a temperature of the wash liquid in the
tub 14 satisfies the first temperature threshold. In this scenario,
a temperature sensor 92 may be configured to determine a
temperature of the liquid collecting in the tub 14 and the
controller 82 may be configured to stop the supply of liquid when
the liquid in the tub 14 satisfies the first predetermined
temperature threshold.
[0047] At 208 the laundry load may be moved through the hot
pre-wash liquid to facilitate treatment of the laundry load with
the pre-wash liquid. Moving the laundry through the hot pre-wash
liquid may include recirculating the pre-wash liquid collected in
the tub 14 through the recirculation system and/or rotating the
drum 20. Alternatively, or additionally, the clothes mover 26 can
be actuated to move the laundry load through the pre-wash liquid to
facilitate treating the laundry with the pre-wash liquid. When the
volume of pre-wash liquid is such that the laundry is partially
immersed or fully submerged in the pre-wash liquid, rotation of the
drum 20 and actuation of the clothes mover 26 may be used to
facilitate treating the laundry with the pre-wash liquid.
Recirculation of the pre-wash liquid may be utilized to further
facilitate treating the laundry with the pre-wash liquid. When the
volume of pre-wash liquid is such that the fill level is below a
level which contacts the laundry, recirculation may be used to
treat the laundry with the pre-wash liquid and rotation of the drum
20 and actuation of the clothes mover 26 may optionally be used to
move the laundry to facilitate evenly treating the laundry.
Rotation of the drum 20 and actuation of the clothes mover 26 may
also impart mechanical action to the laundry to facilitate lifting
soils from the laundry. The laundry load may be moved through the
pre-wash liquid for a predetermined period time to soften and melt
fatty based soils present on the laundry to facilitate lifting of
the soils by the detergent composition. However, it may be
beneficial to minimize prolonged exposure to hot liquid in a
temperature range of 95-115.degree. F. to avoid damaging the
laundry fabric. In one example, the laundry may be moved through
the hot pre-wash liquid for a period of 2 to 10 minutes.
[0048] Still referring to FIG. 4, following the pre-wash phase 102,
the main wash phase 104 may begin with forming a main wash liquid
at 210. The main wash liquid formed at 210 may be formed by
supplying additional water to the tub 14 from the water supply
source 42 to increase the amount of liquid in the tub 14 to the
main wash fill level. The main wash tub fill level may be
determined by the controller 82 using pre-programmed algorithms or
stored look-up tables relating the fill level to one or more
characteristics of the laundry, the selected cycle of operation,
and/or the specific machine implementing the cycle. Generally, the
main wash tub fill level is in the range of 18-36 liters, and may
vary depending on the type and/or amount of laundry and
characteristics of the washing machine, such as the dimensions of
the tub, drum and/or sump. An illustrative amount of main wash
liquid for a 3.6 kg AHAM standard 100% cotton load is 28 liters.
The amount and temperature of the main wash liquid may also be
selected to provide a predetermined amount of a main wash liquid at
a predetermined temperature and/or having a predetermined
concentration of the detergent composition for treating the laundry
during the main wash phase 104.
[0049] In one exemplary embodiment, the controller 82 controls the
cold water valve 48 to supply cold water to the tub 14 to form a
main wash liquid having a temperature less than the temperature of
the pre-wash liquid during the pre-wash phase 102. A preferred
temperature range for the main wash liquid is in the range of
60-95.degree. F., although the temperature may vary depending on
the selected cycle of operation, the volume of water added and the
temperature of the water added. The temperature of the wash liquid
may be monitored using the temperature sensor 92 and the volume and
temperature of the added water may be controlled by the controller
82 such that the temperature of the main wash liquid when the main
wash fill level is reached satisfies a predetermined temperature
threshold. Alternatively, cold water may be added to the tub 14 to
reach the main wash fill level with the assumption that the
temperature of the main wash liquid at the main wash fill level
satisfies a predetermined temperature threshold, such as below
95.degree. F., for example.
[0050] In most scenarios, because of the high temperature of the
hot pre-wash liquid, only cold water will be supplied to the tub 14
to reach the main wash fill level and decrease the temperature of
the wash liquid to a temperature suitable for the main wash phase
104. However, it is within the scope of the invention for both hot
and cold water to be added to the tub 14 to form the main wash
liquid having a desired temperature at 210.
[0051] The increase in volume from the pre-wash fill level to the
main wash fill level decreases the concentration of the detergent
composition, and any additional treating chemistries that may have
been added prior to or during the pre-wash phase 102. The amount of
detergent composition supplied during the pre-wash phase 102 may
have been selected at least in part to provide a predetermined
concentration of the detergent composition during the main wash
phase 104. Depending on the amount of liquid added to form the main
wash liquid, additional detergent composition may be added to
provide the main wash liquid with the desired concentration of the
of the detergent composition during the main wash phase 104.
Additional detergent and other treating chemistries may also be
added during the main wash phase 104 depending on the selected
cycle of operation.
[0052] At 212, the laundry load may be moved through the main wash
liquid to facilitate treatment of the laundry load with the main
wash liquid. Moving the laundry through the main wash liquid may
include recirculating the main wash liquid in the tub 14 through
the recirculation system and/or rotating the drum 20.
Alternatively, or additionally, the clothes mover 26 may be
actuated to move the laundry load through the wash liquid to
facilitate treating the laundry with the wash liquid. When the
volume of wash liquid is such that the laundry is partially
immersed or fully submerged in the wash liquid, rotation of the
drum 20 and actuation of the clothes mover 26 may be used to
facilitate treating the laundry with the wash liquid. Recirculation
of the wash liquid may be utilized to further facilitate treating
the laundry with the wash liquid. When the volume of wash liquid is
such that the fill level is below a level which contacts the
laundry, recirculation may be used to treat the laundry with the
wash liquid and rotation of the drum 20 and actuation of the
clothes mover 26 may optionally be used to move the laundry to
facilitate evenly treating the laundry. Rotation of the drum 20 and
actuation of the clothes mover 26 may also be used to impart
mechanical action to the laundry to facilitate lifting soils from
the laundry. At 214, the cycle may continue on to the remaining
phases of the cycle.
[0053] Table 1 illustrates an exemplary cycle of operation for a
3.6 kg AHAM 100% cotton load treated according to the cycle of
operation 100 and method 200 of FIGS. 3 and 4, respectively.
TABLE-US-00001 TABLE 1 Exemplary cycle for a 3.6 kg AHAM 100%
cotton load. Anti-stain setting phase Pre-wash phase Main wash
phase Treating chemistry None Detergent Detergent composition
composition Treating chemistry 0X or >4.5X 1.5X-4.5X 1X
concentration* Liquid level Dampen (2-8 liters Saturate (8-18
liters Submerge (18-36 or a liquid to or a liquid to liters or a
liquid to laundry ratio of 0.5-2.2) laundry ratio of 2.2-5) laundry
ratio >5) Wash liquid Cold (60-80.degree. F.) Hot
(95-115.degree. F.) Warm (60-95.degree. F.) temperature Treatment**
Tumble load with Tumble load with Tumble load with recirculation
recirculation and recirculation and agitation agitation
*Concentrations are listed as multiples of the concentration used
in the corresponding main wash phase. A concentration of "0X"
refers to the absence of a treating chemistry; a concentration of
"2X" refers to a concentration that is twice that found in the
corresponding main wash phase. **One or more of the phases may
optionally include a low or medium speed spin phase.
[0054] Referring now to FIG. 5, a method 300 for forming a pre-wash
liquid having a temperature that satisfies a predetermined
temperature threshold is illustrated. The method 300 may be used at
206 of the method 200 of FIG. 4 to form the hot pre-wash liquid or
any other method for forming a wash liquid satisfying a
predetermined temperature threshold. The method 300 is configured
for use with a washing machine that is connected with a hot water
supply and may be used in washing machines which do not include an
internal heating system or during cycles in which it is undesirable
to utilize the washing machine's internal heating system, such as
to save energy.
[0055] Still referring to FIG. 5, at 302, the controller 82 may
control the hot water valve 46 to supply externally heated water to
the tub 14. At 304, the temperature of the hot liquid collecting
within the tub 14 may be determined by the controller 82 based on
an output from the temperature sensor 92. The temperature sensor 92
may continuously or incrementally output a value indicative of the
temperature of liquid to the controller 82 (e.g. a voltage output
that correlates with a temperature value). The temperature of the
liquid may be determined using a single sensor reading or an
average of multiple sensor readings. After a predetermined period
of time, or, alternatively, after a predetermined amount of liquid
has been supplied, the controller 82 may determine whether the
temperature of the liquid satisfies a predetermined second
temperature threshold at 306. Preferably, the predetermined period
of time or predetermined amount of liquid corresponds to a fill
level that does not wet the laundry.
[0056] If the temperature of the wash liquid satisfies the second
temperature threshold at 306, the method may proceed at "A" to 206
of the method 200 of FIG. 4 to continue with the pre-wash phase
102. If the temperature of the wash liquid does not satisfy the
second temperature threshold, at 308 it may be determined whether a
number of drain cycles implemented during the cycle has exceeded a
predetermined threshold. If the number of drain cycles implemented
during the cycle exceeds the predetermined threshold, the method
may proceed at "A" to 206 of the method 200 of FIG. 4 to continue
with the pre-wash phase 102, regardless of the temperature of the
wash liquid. If the number of drain cycles implemented during the
cycle does not exceed the predetermined threshold, at 310 liquid in
the tub 14 may be drained from the tub 14 and the method may return
to 302 to repeat the supply of hot liquid until the temperature
threshold is satisfied at 306.
[0057] Preferably the amount of time it takes to form the hot
pre-wash liquid is minimized, as it is generally not desirable to
lengthen a cycle of operation any more than is necessary to provide
the desired laundry treatment. During the anti-stain setting phase
101, cold water from the water supply source 42 is supplied to the
laundry, which may result in cold water remaining in a path between
the spray nozzle 56 and the cold water valve 48. The cold water
remaining in this path will be supplied into the tub 14 when the
hot water valve 46 is opened. Depending on the amount and
temperature of the cold water in this path, the cold water may
undesirably increase the time and amount of hot water that needs to
be supplied to form the hot pre-wash liquid at a temperature that
satisfies the first predetermined temperature threshold. The method
300 may be used to purge this cold water from the system prior to
adding hot water to avoid unnecessarily lengthening the cycle or
increasing the volume of the pre-wash liquid.
[0058] The second predetermined temperature threshold at 306 may be
the same as the first predetermined temperature threshold at 206 of
the method 200 of FIG. 4 or different. In one example, the second
predetermined temperature threshold may be set based on a
temperature that indicates that the first predetermined temperature
threshold at 206 will be satisfied within a predetermined period of
time and/or at a predetermined fill level, which may be a threshold
less than the first predetermined temperature threshold. The
determination at 306 may be made at a predetermined period of time
following the start of the fill process or at a predetermined fill
level which preferably is based on a fill level that does not wet
the laundry, as wetting of the laundry with cold water may increase
the time and energy required to form the hot pre-wash liquid.
[0059] The threshold for the number of drain cycles at 308 may be
set at any desired number such that the method 300 is only repeated
a predetermined number of times before the cycle continues onto the
next phase or stage so as to not extend the length of the cycle
more than a desired amount.
[0060] During the supply of hot liquid at 302, the liquid is
preferably added to the tub 14 without contacting the laundry. In
this manner, if the temperature of the supplied liquid is lower
than desired, the low temperature liquid does not contact the
laundry, which may increase the time and energy required to form
the hot pre-wash liquid to melt and/or soften the fatty soils. Some
washing machines supply the water from the water supply source 42
directly to the tub 14. However, for washing machines in which the
water is supplied into the drum 20, such as illustrated for the
washing machine 10 of FIG. 1, the drum 20 may be rotated to move
the laundry to the periphery of the drum 20 such that the liquid
may be added to the tub 14 through the drum 20 while bypassing the
laundry within the drum 20. Application Ser. No. 14/275,025, filed
May 12, 2014, entitled "Methods and Compositions for Treating
Laundry Items," the contents of which are herein incorporated by
reference in full, discloses a method whereby the drum is rotated
to impart a centrifugal force to the laundry sufficient to
distribute the laundry about the periphery of the drum to form an
annulus of laundry within the treating chamber and liquid is
supplied to the tub via the drum by supplying the liquid through a
center of the annulus of laundry such that the liquid bypasses the
laundry and flows through the perforations in the drum into the
tub.
[0061] The cycle and methods for implementing the cycle described
herein provide a method for removing fatty soils from laundry that
may be difficult to remove, especially in high efficiency washing
machines which use low fill levels and low liquid temperatures as
well as on laundry which typically includes instructions to wash at
low temperatures, such as active or sportswear. The embodiments
described herein utilize a hot pre-wash liquid at temperatures that
may melt or soften many of these fatty soils to facilitate lifting
the soils from the laundry by a detergent composition, which is
present at a higher concentration in the pre-wash liquid than used
during a typical wash phase to further facilitate lifting the soils
from the laundry.
[0062] However, as discussed above, hot liquid, particularly in the
temperature ranges according to the embodiments of the invention
that melt/soften fatty soils, may set some protein-based stains,
such as blood, which make these stains difficult, if not impossible
to remove. A protein in its native 3-D shape will have hydrophobic
amino acids hidden within the structure of the protein and
hydrophilic amino acids on the outside, enabling the protein to be
soluble in water. When denatured, the bonds holding the amino acids
together are disrupted and the protein loses its 3-D structure and
so some hydrophobic amino acids may become exposed on the surface
of the structure, decreasing the water solubility of the protein.
Decreasing the water solubility of the protein may result in the
protein precipitating out of solution, but in some cases, depending
on the nature of the fabric, may actually result in an increase in
the interaction between the denatured protein and the fabric.
Fabrics having a hydrophobic component, such as polyester and other
synthetics, which are often used in active and sportswear, may
interact with the exposed hydrophobic amino acids, inhibiting
removal of the protein from the fabric surface. The embodiments of
the invention described herein provide a method for facilitating
the removal of fatty soils without undesirably diminishing the
ability to remove protein-based stains.
[0063] The embodiments of the invention may be used with an active
or sportswear cycle to facilitate removal of fatty soils from
active or sportswear items, especially those made using synthetic
materials. Most active or sportswear cycles are designed to wash
the items in cold or warm water, with gentle agitation, and in the
case of high efficiency washers, low fill volume. These
parameters--cold/warm water, gentle agitation, and low volume--are
generally not efficient in lifting fatty stains. The cycle and
methods described herein provide a hot, low volume, concentrated
detergent pre-wash phase which facilitates removal of fatty stains
that may be combined with a main wash phase configured to wash the
laundry in accordance with typical active/sportswear wash
instructions, while at the same time providing an anti-stain
setting phase minimize setting stains during the hot pre-wash
phase.
[0064] To the extent not already described, the different features
and structures of the various embodiments of the invention may be
used in combination with each other as desired. For example, one or
more of the features illustrated and/or described with respect to
one of the cycles or methods 100, 200 or 300, can be used with or
combined with one or more features illustrated and/or described
with respect to the other of the cycles or methods 100, 200 or 300.
That one feature may not be illustrated in all of the embodiments
is not meant to be construed that it cannot be, but is done for
brevity of description. Thus, the various features of the different
embodiments may be mixed and matched as desired to form new
embodiments, whether or not the new embodiments are expressly
described.
[0065] While the invention has been specifically described in
connection with certain specific embodiments thereof, it is to be
understood that this is by way of illustration and not of
limitation. Reasonable variation and modification are possible
within the scope of the forgoing disclosure and drawings without
departing from the spirit of the invention which is defined in the
appended claims.
* * * * *