U.S. patent application number 13/887585 was filed with the patent office on 2014-01-30 for method for washing coloured clothes in a domestic washing machine.
This patent application is currently assigned to Whirlpool Corporation. Invention is credited to CLAUDIO CIVANELLI.
Application Number | 20140026330 13/887585 |
Document ID | / |
Family ID | 46603672 |
Filed Date | 2014-01-30 |
United States Patent
Application |
20140026330 |
Kind Code |
A1 |
CIVANELLI; CLAUDIO |
January 30, 2014 |
METHOD FOR WASHING COLOURED CLOTHES IN A DOMESTIC WASHING
MACHINE
Abstract
A method for washing coloured clothes in a domestic washing
machine comprises a preliminary phase in which water and an
additive containing a colour protector compound are added to the
tub, a tumbling phase in order to allow wetting of clothes and a
spinning phase for removing at least a portion of water and
additive from clothes before starting a washing program, the
temperature of water and additive being preferably comprised
between 5.degree. C. and 30.degree. C.
Inventors: |
CIVANELLI; CLAUDIO;
(Travedona Monate, IT) |
Assignee: |
Whirlpool Corporation
Benton Harbor
MI
|
Family ID: |
46603672 |
Appl. No.: |
13/887585 |
Filed: |
May 6, 2013 |
Current U.S.
Class: |
8/137 |
Current CPC
Class: |
D06F 35/005 20130101;
D06F 33/00 20130101; D06F 23/00 20130101 |
Class at
Publication: |
8/137 |
International
Class: |
D06F 23/00 20060101
D06F023/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 27, 2012 |
EP |
12178331.0 |
Claims
1-8. (canceled)
9. A method of washing coloured clothes in a domestic washing
machine having a tub and a rotatable drum located within the tub,
the method comprising: a washing phase where a detergent solution
is added to the tub and the drum is rotated within the detergent
solution; and a pre-washing phase, preceding the washing phase,
comprising: water and an additive containing a colour protector
compound are added to the tub to form a pre-treatment solution;
rotating the drum to tumble clothes in the drum in the pretreating
solution to wet the clothes within the drum with the pretreating
solution; and spinning the drum to extract at least a portion of
the pre-treatment solution from clothes.
10. The method according to claim 9, wherein the pre-treatment
solution is between 5.degree. C. and 30.degree. C.
11. The method according to claim 10, wherein the pre-treatment
solution is heated.
12. The method according to claim 9, wherein the pre-washing phase
comprises, after the spinning the drum, rinsing the clothes in the
drum with water.
13. The method according to claim 9, wherein the rotating the drum
to tumble clothes occurs for a predetermined time.
14. The method according to claim 13, wherein the predetermined
time comprises 5 to 20 seconds.
15. The method according to claim 9, wherein the pre-washing phase
comprises draining the extracted portion of the pre-treatment
solution.
16. The method according to claim 15, wherein the draining occurs
prior to the spinning the drum to extract.
17. The method according to claim 9, wherein the colour protector
compound is a quaternary ammonium compound.
18. The method according to claim 17, wherein the additive is a
commercial rinse conditioner.
19. The method according to claim 17, wherein the concentration of
rinse conditioner in water is between 1 ml/l and 10 ml/l.
20. The method according to claim 9, wherein, after the washing
phase, a rinsing phase where fresh water is added to the tub and
the drum is rotated.
21. The method according to claim 20, wherein, after the washing
phase and prior to the rinsing phase, an extraction phase where the
drum is spun to remove the detergent solution from the clothes.
22. A method of washing coloured clothes in a domestic washing
machine having a tub and a rotatable drum located within the tub,
the method comprising: a washing phase wherein a detergent solution
is provided onto clothes within the drum; a pre-washing phase,
preceding the washing phase, comprising providing a pre-treatment
solution comprising water and an additive containing a colour
protector compound onto clothes in the drum, followed by an
extracting of at least a portion of the pre-treatment solution from
the clothes; and a rinsing phase, after the washing phase, where
the detergent phase is rinsed from the clothes.
23. The method of claim 22, wherein the pre-washing phase comprises
tumbling the clothes in the pretreating solution to wet the
clothes.
24. The method of claim 22, wherein the pre-washing phase comprises
draining the extracted portion of the pre-treatment solution.
25. The method of claim 22, wherein the pre-washing phase
comprises, after the extracting, rinsing the clothes in the drum
with water.
26. The method of claim 22, wherein the colour protector compound
is a quaternary ammonium compound.
27. The method of claim 22, wherein the additive is a commercial
rinse conditioner.
28. The method of claim 27, wherein the concentration of rinse
conditioner in water is between 1 ml/l and 10 ml/l.
Description
[0001] The present invention relates to a method for washing
coloured clothes in a domestic washing machine comprising a washing
tub.
[0002] It is well known in the art of domestic appliances that a
washing program of a domestic washing machine comprises a first
washing phase in which water and detergent are added to the washing
tub, followed by a tumbling phase in which the clothes are moved
inside a drum rotating in the tub in order to guarantee the proper
interaction between detergent and clothes, a rinsing phase during
which detergent is removed from clothes and a rinsing agent or
conditioner is added to clothes, and a final spinning phase in
which rinsing water is mostly removed from clothes. Of course there
can be differences in the basic washing program (for instance there
can be a pre-washing phase for particularly dirty clothes), but
basically the above phases are always present in known washing
programs.
[0003] A technical problem encountered in washing machines using
traditional washing programs is the colour fading and the colour
transfer. These are two well known phenomena that affect negatively
the washing process of coloured garments.
[0004] The colour fading is the loss of colour of a coloured
garment that in time causes a brilliant tint to become paler with
an evident "old" aspect and a significant loss of appeal.
[0005] At the same time the dye that is released in the washing
liquor can be absorbed by a white or a light coloured item,
changing the original colour in an undesired way. The above issues
are among the major concerns for the domestic laundry in the
present market.
[0006] The textile industries are using a variety of different dyes
and a variety of different processes to produce coloured items,
depending on different fibres and textiles.
[0007] Among dyes, the kind that gives most of the described issues
is a dye category used for cotton and known as `direct` dyes. These
are also the dyes which are most used by textile industries.
[0008] In the recent years, some of the producers of chemicals for
domestic use have launched on the market some `absorbing` sheets
that are claimed as capable to prevent the colour transfer and,
more recently, also the colour fading. What those sheets do is
simply to absorb some of the dyes that are released in solution by
the coloured garments, becoming coloured themselves, and giving the
user the impression to have captured all of the `dangerous` dyes
that could `stain` their whites. One of the known solutions of
using a dye scavenger sheet comprising a cellulosic substrate
material bearing a dye scavenger chemical is disclosed by U.S. Pat.
No. 4,380,453.
[0009] If on one side it is true that those scavenger sheets are
capable to capture some of the dyes, it is also true that this kind
of action is not enough to prevent safely a colour transfer.
[0010] Even if in the professional market colour protectors are
used in a pre-treatment, i.e. before an industrial washing cycle,
nevertheless this kind of treatment has remained during years
confined in the professional washing market. The main component of
these known colour protectors belong to a class of organic
substances known as quaternary ammonium salts or "quats". They have
a general formula R.sub.4N.sup.+X.sup.- where R represents an
organic radical and X.sup.- is a compatible anion:
##STR00001##
[0011] R.sup.1 is usually a C.sub.12 to C.sub.22 alkyl or alkenyl
chain; R.sup.2, R.sup.3 and R.sup.4 are independently selected from
C.sub.1 to C.sub.4 alkyl chains. A usual compound of this type is
the quaternary ammonium compound cetyl trimethyl quaternary
ammonium bromide.
[0012] But of course there is a number of different quats, with a
number of different usages, including disinfection, fabric
softening, colour protection and so on.
[0013] It is an object of the present invention to provide a method
for washing coloured clothes in a domestic washing machine which
can avoid or limit colour fading and/or colour transfer, and
without the need of using dye scavenger sheets or similar
devices.
[0014] The above object is reached thanks to the features listed in
the appended claims.
[0015] The applicant has discovered that with a modification of the
normal washing cycle and with the addition of a commercial additive
containing a colour protector it is possible to have very good
results in terms of low colour fading and colour transfer,
surprisingly comparable with the results obtained in professional
washing market where specific colour protectors are used.
[0016] Surprisingly, the applicant has discovered that by using a
rinse conditioner (known also as "fabric softener") in a
preliminary wetting phase before the usual washing program, the
amount of quaternary ammonium compound contained in the commercial
rinse conditioner is sufficient for getting good result in terms of
colour fading and colour transfer, without any interaction problems
with other compounds contained in the rinse conditioner. This has
the further advantage of not adding another chemicals to the ones
already used during washing cycle.
[0017] According to another feature of the present invention, in
order to limit the negative interaction between the quaternary
ammonium compound and the anionic surfactants contained in the
detergent used in the washing phase, after the preliminary wetting
phase with water and additive containing the colour protector
compound, the laundry undergoes a spinning phase for removing at
least the major quantity of such compound.
[0018] Given the above similarity between the colour protectors
compounds and the fabric softener (particularly as far as the
common active compound is concerned), the applicant has designed
for a domestic washer a specific cycle for the coloured garments
that includes a pre treatment before the washing phase. This
specifically designed pre-treatment may use both the fabric
softener as well as a specific product for the colour protection.
The overall result is a washing cycle that cleans the coloured
garments but at the same time limits or avoids the two undesired
effects of colour fading and colour transfer. The availability of
this cycle in a domestic washing machine gives to the user the
possibility to wash garments of different colours and also white
garments without the need of sorting them.
[0019] Further advantages and features of a method and of a washing
machine according to the invention will become clear thanks to the
following detailed description, with reference to the attached
drawings in which:
[0020] FIG. 1 is an experimental chart showing the result of tests
on the behaviour of white samples added to a 2 kg cotton load
referring to the original reflectance value and variations measured
after the first, second, third and fourth washing cycle and by
using or not using a method according to the invention;
[0021] FIGS. 2-4 are experimental charts showing the results of a
series of tests carried out using coloured samples (red, blue and
black respectively) added to a 2 kg cotton load.
[0022] With reference to the drawings, the tests have been done
using coloured test specimens that, if washed in a normal cycle,
release the dye. The washing machine used for the test is a
commercial Whirlpool washer AWO/D 6188 WP (8 kg) modified in order
to carry out the preliminary phase according to the invention. The
detergent used for all tests is 60 ml of "Perlana Nero Assoluto"
produced and sold by Henkel.
[0023] The specimen are used in the ISO testing for the colour
transfer and are coloured using dyes belonging to the group of the
so called `direct dyes`, which are the dyes more critical from the
point of view of the colour fading and transfer.
[0024] The measurement on these specimens has been done using the
same colorimeter used for the measurement of the soil removal.
[0025] The desired effect is that the white remains white (so
keeping a high percentage of reflectance) and the intense colour
remain intense (so keeping a reflectance value as low as
possible).
[0026] The chart of FIG. 1 shows the behaviour of the white sample
referring to the original reflectance value and the variation
measured after the first, second, third and fourth washing
cycle.
[0027] The comparison is among the use of the detergent only
(including a preliminary phase with water only), the pre-treatment
done with 30 ml of a commercial fabric softener Downy (Procter
& Gamble--containing about 15% of quaternary ammonium cationic
compounds) and about 10 litres of water, and a pre-treatment done
with 30 ml of a professional colour protector produced and sold by
the company Alberti Angelo in the same amount of water used for the
commercial fabric softener.
[0028] The Y axis shows the percentage of variation of the
reflectance.
[0029] It is immediately evident from FIG. 1 that the fabric
softener and the color protector are capable to preserve better the
white (higher reflectance value) than the detergent only. Some
variation in the measurement are normally caused by the measurement
noise but, despite of that, the trend is absolutely evident.
[0030] The measurement done on the red samples (FIG. 2) shows a
clear increase of the `whiteness` of the sample, that means simply
a fading of the original color, when the pre-treatment is not used
(detergent only).
[0031] It is absolutely evident that the pre-treatment with both
chemicals (softener and professional protector) reduces
substantially the fading, preserving the brilliance and the
sharpness of the color for a longer time. It is also clear that if
the garment looses less color, there is less dye in solution that
can be transferred to other items.
[0032] The blue specimen (FIG. 3) behaves in a very similar manner.
Once again there is a clear evidence of color protection with both
chemicals.
[0033] The black sample (FIG. 4) shows a quite surprising trend to
increase the color intensity. This may be due to a starting value
of reflectance that is very low (the absolute magnitude is around
4% of reflected light) and so even small variations due to the
noise of the measurement are amplified by the low reference figure.
Despite of that, the trend of the protection effect is well
visible.
[0034] As shown in the charts, there is evidence of color
protection and reduction of colour transfer by using both the
fabric softener and professional protector. Very similar results
have been obtained by using other commercial fabric softeners,
particularly "Fabuloso concentrato" (30 ml) produced and sold by
Colgate, W-pro fabric softner produced and sold by the applicant
(30 ml), Carrefour softner (25 and 50 ml). The content of ammonium
cationic compounds in "Fabuloso concentrato" (as declared by the
producer) is higher than 25%, while in the other two softeners it
is above 15%.
[0035] In general, good results in terms of colour protection are
obtained with a concentration of the commercial fabric softener
comprised between 1 and 10 ml of softener per litre of water, i.e.
a volume concentration between 0.1% and 1%.
[0036] Unfortunately, the behaviour of the two chemicals (softner
and colour protector) interferes with the action of the detergent.
Cationics surfactants (fabric softener) and in general the quats,
react with the anionic surfactant of the detergents forming
unsoluble compounds. This causes two different, undesired effects:
[0037] the concentration of the available anionic surfactant
decreases, decreasing the cleaning power of the washing solution;
[0038] the insoluble compound may precipitate on garments or on
washer surfaces; this may cause spots on the garments and, in the
long run, deposition of sludge on the washer.
[0039] In order to minimize the interaction between the color
protection and the washing action, it is important to reduce as
much as possible the amount of quats remaining in the solution
after pre-treatment.
[0040] The above is achieved by increasing the spin speed between
the pre-treatment and the main wash or even by introducing a rinse
step after pre-treatment. The applicant has discovered that the
concentration of ammonium compounds on the fabric even after a
water rinse step is sufficient for yielding the colour protection
effect.
[0041] Temperature, duration, chemical concentration, spin speed,
are among the parameters that require tuning to get the optimal
performance, depending also on the washing machine used and on the
fabric softener used. This tuning can be easily done by a person
skilled in the art of designing washing machines.
[0042] The pre-treatment has been preferably structured as follows:
[0043] pre-fill of clean water; [0044] introduction of the
protective chemical by water flow, while tumbling; [0045] heating
to a predetermined temperature, preferably between 5.degree. C. and
30.degree. C., while tumbling; [0046] tumbling for a predetermined
time (usually comprised between 5' and 20') to mix carefully;
[0047] drain of the used liquor; [0048] spin extraction.
[0049] At the end of the above steps, the normal washing cycle will
start, which can be preceded by the already mentioned extra rinse
phase.
[0050] In conclusion, there is a clear evidence that the
pre-treatment according to the invention works for the color
protection and brings a clear advantage for the consumer using a
domestic washer. It protects the colors, particularly of cotton
garments, maintaining for much longer the original brightness.
[0051] The experiments done so far by the applicant show without
any doubt that the theory works and the special cycle according to
the invention delivers an unmatched result in a domestic washer as
far as colour protection is concerned.
[0052] The modifications of a usual washing machine in order to
make it fit for carrying out a method according to the invention
are quite limited. In the detergent and additives distributor it is
necessary to add a container or drawer which can be flushed by
water into the tub and the user interface has to be provided with a
button or knob which is related to the special "colour" program,
driven by a control process unit which controls either the amount
of water to be added in the preliminary step, the duration of
tumbling, the temperature to be reached in such preliminary phase
and the final spinning speed and time.
* * * * *