EP3665322B1

EP3665322B1 - Light-promoted stain removal system

Info

Publication number: EP3665322B1
Application number: EP18752733.8A
Authority: EP
Inventors: Yile LIAO; Kannan Udayappan PRAVEEN
Original assignee: Koninklijke Philips NV
Current assignee: Koninklijke Philips NV
Priority date: 2017-08-07
Filing date: 2018-08-07
Publication date: 2021-10-06
Anticipated expiration: 2038-08-07
Also published as: EP3665322A1; CN111032951A; US20200270791A1; CN111032951B; WO2019030215A1

Description

FIELD OF THE INVENTION

The invention relates to the field of stain removal.
The invention may for example be used in the field of fabric care, such as garment care.

BACKGROUND OF THE INVENTION

Oxidizing agents are widely used in area of cleaning, disinfecting and bleaching. Oxidizing agents like hydrogen peroxide having formula H₂O₂, carbamide, sodium percarbonate, sodium perborate are also very widely added in laundry powders and detergents to remove stains on garment.
The chemical reacting mechanism of stain removing by oxidization mechanism is illustrated by Fig. 12.
The stain comprises colored molecule (chromophore) defining a first product P1.
The colored molecule is then oxidized by an oxidization agent or bleach, resulting in an intermediate product P2.
Water is then applied to the intermediate product, resulting in a colorless molecule defining a final product P3.
As the H₂O₂ concentration in commercial stain removing products is low, the bleaching reaction is not very effective and requires comparatively longer time to diminish the stain color, normally 5 min to 30 min treatment time is needed depending on the stain age and stain type.
Reaction can be accelerated by using high temperature (e.g. 70 degreeC) to reduce the treatment time significantly. But there is a risk of user's skin being injured if apply the high temperature stain removal system without taking off the stained cloth.
Published patent US2015225891A1 relates to a method of cleaning a substrate comprising a fabric material with optical energy, comprising applying cleaning agent to the fabric material, and applying optical energy from a source of optical energy to the fabric material having the cleaning agent applied thereto, the optical energy having one or more optical parameters selected for cleaning the fabric material.

SUMMARY OF THE INVENTION

It is an object of the invention to propose a stain removal system that avoids or mitigates above-mentioned problems.
The invention is defined by the independent claims. The dependent claims define advantageous embodiments.
To this end, the stain removal system for treating a stained area on a cloth comprises:

a container for containing a bleach chemical, wherein the container is a removable cartridge,
a system for carrying the bleach chemical to the stained area under a liquid form,
a light source for generating light radiation over the stained area.

Light acceleration is a good substitution of heat. A stain removal system with light source integration allows fast stain removing and user can use it to treat a stain on clothes while they are wearing it.
Small and light weight of the light source also enables designing a compact, portable stain removal system that is convenient for user to handle and bring along.
The invention also relates to a cartridge forming a container for containing a bleach chemical. The cartridge is adapted to cooperate with a stain removal system as described above. The cartridge may for example be adapted to couple to the stain removal system via a coupling valve arrangement. This may allow firm holding of the cartridge and also prevent any leakage of the bleach chemical. The coupling valve arrangement may be a part of the cartridge, or may be a part of the system to which the cartridge is adapted to cooperate.
The invention also relates to a method of treating a stained area on a cloth by a stain removal system as described above.
Detailed explanations and other aspects of the invention will be given below.

BRIEF DESCRIPTION OF THE DRAWINGS

Particular aspects of the invention will now be explained with reference to the embodiments described hereinafter and considered in connection with the accompanying drawings, in which identical parts or sub-steps are designated in the same manner:

Fig.1 depicts a first stain removal system according to the invention,
Fig.2 depicts a second stain removal system according to the invention,
Fig.3 depicts a third stain removal system according to the invention,
Fig.4 depicts a stain removal system according to the invention comprising a detachable container for containing a liquid bleach chemical,
Fig.5 depicts a stain removal system according to the invention comprising a container for containing a first type of solid bleach chemical,
Fig.6A is a zoomed view of the container as depicted in Fig.5 for containing a first type of solid bleach chemical,
Fig.6B is a zoomed view of a container for containing a second type of solid bleach chemical,
Fig.7 depicts a three-dimensional view of a stain removal system as depicted in Fig.5,
Fig.8A depicts an internal view of a stain removal system as depicted in Fig.5,
Fig.8B depicts a three-dimensional cross-section of a front end of the system as depicted in Fig.8A,
Fig.8C depicts a two-dimensional cross-section of a front end of the system as depicted in Fig.8A,
Fig.8D depicts a quantitative example of a two-dimensional cross-section of a front end of the system as depicted in Fig.8A,
Fig.9 depicts a stain removal system according to the invention comprising a heater fan,
Fig.10 depicts a stain removal system according to the invention comprising an infra-red lamp,
Fig.11 depicts a flow chart of a method according to the invention of treating a stained area by a stain removal system,
Fig.12 illustrates the chemical reacting mechanism of stain removing by oxidization mechanism.

DETAILED DESCRIPTION OF EMBODIMENTS

In the following, a bleach chemical refers to a group of chemicals that work through oxidation mechanisms to remove a stain. Including liquid type of bleach chemical like hydrogen peroxide and peroxy acids and solid type of bleach chemical like sodium percarbonate, sodium perborate, carbamide peroxide, etc.
The invention is based on the principle that light activation of hydrogen peroxide H₂O₂ helps peroxide decompose faster to form free radicals that react with organic molecules (stain colors).
Below is the light activated free radical generation:

H₂O₂ + hv → 2 OH• (1)

OH• + H₂O₂ → HO₂• + H₂O (2)

HO₂• + H₂O₂ → OH• + H₂O + O₂ (3)

2 HO₂•→ H₂O₂ + O₂ (4)
In above chemical reactions, "hv" corresponds to the chemical equation for photon.
Selection of the light source, wavelength, intensity and exposure time affect the bleaching efficiency.
Light source can for example correspond to UV light which has a high photon energy. Blue light can also be considered. Although light source of longer wavelengths has lower photon energy which may result in less efficient photo catalysis, more heat generated by the longer wavelength light can still increase the oxidizing reaction.
Typical spectrum for blue light is between 492nm to 455nm.
Preferably, to ensure an efficient stain removal, the power of the light source is at least 500mW.
In this invention, blue light is applied as an example but other light sources like IR, white light, green light etc. should not be excluded from the same principle.
Fig.1 depicts a first stain removal system 101 according to the invention for treating a stained area 102 on a cloth 103.
The stain removal system comprises:

a container 104 for containing a bleach chemical,
a system 105 for carrying the bleach chemical to the stained area 102, and
a light source 106 for generating light radiation 107 over the stained area 102.

The container 104 may for example correspond to a bottle or recipient, as illustrated. For example, the bottle can be detachable from the device 101.
The system 105 for carrying the bleach chemical may correspond to the spout of the bottle, for example forming an elongated outlet.
The liquid bleach chemical is externally provided and dosed by user onto the stained area. The bleach chemical is in liquid form for this type of execution.
The light source 106 is preferably arranged at a front end FE of the system. In particular, the front end FE corresponds to the part of the stain removal system cooperating with the stained area. The light source 106 is preferably but not limited to be light emitting diode (LED) lamps. Higher light intensity increases the radical generation rate and result in better stain removal results.
Fig.2 depicts a second stain removal system 201 according to the invention.
Compared to the embodiment of Fig.1 in which the container 104 containing a bleach chemical is a separate element, the container 204 for containing the bleach chemical in the embodiment of Fig.2 is integrated with all other elements. The container 204 is preferably arranged in a top part of the stain removal system 201.
The system for carrying the bleach chemical to the stained area 102 comprises a tube 202 along which a valve 203 is arranged. The valve 203 can be opened or closed (not shown) by a user, mechanically or electrically, in order to open or close the liquid circuit. When the valve 203 is open, bleach chemical liquid is flowing down by gravity force until reaching the stained area 102.
Fig.3 depicts a third stain removal system 301 according to the invention.
Compared to the embodiment of Fig.2, the system for carrying the bleach chemical to the stained area 102 comprises a tube 202 along which a pump 302 is arranged. The pump 302 is preferably an electrical pump that can be actuated by a switch (not shown) by a user. Alternatively, the pump 302 is a mechanical pump actuated by user via a manual actuator such as a lever. Compared to only using gravity for carrying the bleach chemical, using a pump allows having a faster and increased flow rate of bleach chemical carried to the stained area 102.
It is noted that in the various embodiments according to the invention, the container for containing a bleach chemical can take any form taken among:

a fixed reservoir that can be filled-in by user with a liquid bleach chemical, a removable / detachable reservoir (or cartridge) that can be filled-in by user with a liquid bleach chemical, or
a removable / detachable cartridge being pre-filled with a liquid bleach chemical.

Fig.4 depicts a stain removal system 401 according to the invention.
Compared to the embodiment of Fig.3 in which the container 204 is not detachable, the container 404 in the embodiment of Fig.4 is detachable. The detachable container 404 takes the form of a cartridge containing liquid bleach chemical. The cartridge is coupled to the stain removal system 401 via a coupling valve arrangement 403 that allows a firm holding of the cartridge and also prevents any leakage of liquid chemical.
Fig.5 depicts a stain removal system 501 according to the invention comprising a container 504 for containing a first type of solid bleach chemical 502.
This embodiment comprises a water reservoir 503 and a water path 505a-505b for carrying water from the water reservoir 503 to the container 504 in order to dissolve the solid bleach chemical 502. The resulting dissolved solid bleach chemical releases a bleach solution, like H₂O₂, or mixture of H₂O₂ and peracetic acid, etc.
The water reservoir 503 comprises an opening 506 so that the user can fill-in water when the water reservoir 503 gets empty.
Preferably, a pump 302 is arranged along the water path 505a-505b to facilitate the carrying of water into the container, so that the solid bleach chemical 502 can be dissolved faster and more efficiently.
The solid bleach chemical 502 is arranged inside the container 504 which is closed by a detachable cover 507.
The solid bleach chemical 502 preferably defines a solid-chemical pill that can be dissolved by water. To this end, chemical powder is pressed into a certain shape (for example cylindrical) to form a pill.
Fig.6A is a zoomed view of the container 504 as depicted in Fig.5.
The container 504 comprises an inlet 601 to allow water W to enter in order to dissolve the solid bleach chemical 502. The detachable cover 507 comprises an outlet 602 to let the dissolved chemical solution DCS exit the container 504.
The detachable cover 507 is first detached by user from the body of the container 504. Then user inserts a solid bleach chemical 502 inside the container 504. Then user closes the container 504 by attaching the detachable cover 507 back to the body of the container 504. For example, the detachable cover 507 is detached / attached from the body of the container 504 via a screw arrangement (as illustrated), or a clipping mechanism (not shown).
Fig.6B is a zoomed view of a container 504b for containing a second type of solid bleach chemical 502b.
The container 504b is intended to be used similarly as the container 504 in the embodiment of Fig.5. The container 504b differs from the container 504 in that its size is smaller in order to accommodate a second type of solid bleach chemical 502b having a smaller thickness.
The solid bleach chemical 502b preferably defines a powder-chemical porous pouch. The porous material containing the powder-chemical preferably has a pore size smaller than the grain size of the chemical powder, and is made of non-water dissolvable material forming a soft pod for containing said solid bleach chemical. This powder-chemical porous pouch may look like a "tea-bag".
Fig.7 depicts a three-dimensional view of a stain removal system 501 as depicted in Fig.5.
It shows that the light source 106 is arranged at a front end FE of the stain removal system in order to conveniently face a stained area. The container 504 containing the solid bleach chemical and its cover 507 are arranged in the central part of the front end FE.
Preferably, as illustrated for example in Fig.5, the stain removal system 501 according to the invention further comprises a heating system for heating water of the water reservoir 503.
For example, the heating system is an electrical heater 508 arranged in thermal contact with a bottom part of the water reservoir 503.
The goal of using this heating system is to carry heated water into the container 504 containing the solid bleach chemical.
The heated water provides the benefit of:

dissolving more efficiently and faster the bleach chemical reagent contained in the solid bleach chemical 502 (or 502b), resulting in a higher concentration of reagent obtained quicker.
increasing the chemical reaction rate and efficiency of stain removal.

Alternatively, as illustrated for example in Figs.8A-8B-8C-8D, the heating system for heating water of the water reservoir 503 is formed by a water channel 801 arranged in a heat sink 802 of the light source 106 (not shown in this view).
In order to dissipate heat of the light source, the heat sink 802 is thermally coupled to the light source 106. The heat sink 802 comprises a water channel formed there into. The water channels have a water inlet 804 to which the tubing 505b is connected. When the light source 106 is switched-on, heat is dissipated and absorbed by the heat sink 802. As a result, water circulating into the water channel 801 gets heated before reaching the inlet 601 of the container 504 containing the solid bleach chemical. For example, as illustrated, the water channel 801 is spiral-shaped.
The water that passes in the water channel 801 is heated to a temperature dependent on:

1) the thermal energy generated by the heat sink 802 ,
2) the material type and material mass of the metal plate forming the heat sink 802. Material with very good thermal conductivity like aluminum, copper, or stainless steel is preferred,
3) the time water passing through the water channel 801, and
4) the amount or flow rate of water in the water channel 801.

The estimated temperature range of the heated water is between 40 and 80degreeC. The heated water then passes via the chemical to dissolve the solid bleach chemical and finally on to the garment. Chemical powder can be more effectively dissolved as the water temperature is elevated. And the stain removal effect can be also further increased as the temperature of chemical solution dosed is higher.
Fig.8A depicts an internal view of a stain removal system as depicted in Fig.5.
Fig.8B depicts a three-dimensional cross-section of a front end of the system as depicted in Fig.8A.
Fig.8C depicts a two-dimensional cross-section of a front end of the system as depicted in Fig.8A.
Fig.8D depicts a quantitative example of a two-dimensional cross-section of a front end of the system as depicted in Fig.8A.
Water flows via a tubing 505a-505b from the water reservoir in direction of the container 504 containing the solid bleach chemical. In a cost-effective embodiment, water is only carried under gravity. In another embodiment (as shown), a water pump 302 actuated by a button 803 is inserted along the tubing.
At the front end FE, the light source 106 is arranged, for example a plurality of LEDs. For example, two LED elements of 10W blue light each are arranged at a distance d1 = 1 cm between the center CC of the LED elements and the center of the front end FE. Under such conditions, a red wine stain can be effectively removed within 5 min. This example is illustrated in Fig.8D. With the same light position, the stain removal efficiency/speed is also dependent on chemical formulation selected, as well as the type, concentration, and size of the stain.
Preferably, the distance d1 between a central part of the light source (e.g. LED) and center central part of the front end FE of the system (logically corresponding to the center of the stained area 102 when the system is in contact with the cloth) has a value less 10 centimeters, considering the light intensity at the stain surface should be sufficient and the stain removal system must be as small as possible, in particular if it is a handheld device. Preferably the distance d1 has a value less than 5 cm.
Preferably, the stain removal system according to the invention further comprises a heating system for heating the stained area 102. The heat provided to the stained area 102 allows increasing speed of the chemical reaction during stain removal. Some examples will now be explained in more details along with Figs.9-10.
Fig.9 depicts a stain removal system 901 according to the invention comprising a heater fan 902. The stain removal system 901 is based on the stain removal system 301 depicted along with Fig.3, with an additional heater fan 902.
The heater fan 902 is preferably arranged at a mid-height position of the body of the stain removal system 901. The heater fan 902 combines an air fan 902a and a heating element 902b placed upstream in the air flow. The heater fan 902 primarily generates heat by convection to the stained area 102. The heater fan 902 is activated during the stain removal process.
A top hollow portion 903 is arranged to let (room-temperature) air to circulate towards the air fan 902a. Air flow is illustrated by arrows in dotted line style. A bottom hollow portion 904 is arranged to let the heated air to circulate towards the front end FE. In other words, air 905 that reaches the front end FE corresponds to heated air.
For example, the heater fan 902 is adapted to generate heated air up to 60 degrees Celsius at the front end. This range of temperature allows treating stain without taking off the clothes. At a temperature less than 60degreeC, combined with the use of the fan 902a, water evaporation of the treated stained area is accelerated significantly, leaving the treated clothes with less moisture.
Note that in Fig.9, a container 204 containing a liquid bleach chemical is illustrated. However, similar solution can be implemented with a container for containing a solid bleach chemical, as described above.
Fig.10 depicts a stain removal system 1001 according to the invention comprising an infra-red lamp 1002. The stain removal system 1001 is based on the stain removal system 301 depicted along with Fig.3, with an additional infra-red lamp 1002.
The infra-red lamp 1002 is arranged at the front end FE of the stain removal system 1001, with the goal to primarily generate heat by radiation to the stained area 102. For example, the infra-red lamp 1002 is adapted to generate heated radiation 1003 up to 60 degrees Celsius at the front end FE. This range of temperature allows treating stain without taking off the clothes.
Note that in Fig.10, a container 204 containing a liquid bleach chemical is illustrated. However, similar solution can be implemented with a container for containing a solid bleach chemical.
It is noted that the heater fan and the infra-red lamp can also be used after stain treatment, in order to dry the area where the stained area was initially.
Fig.11 depicts a flow chart of a method according to the invention of treating a stained area 102 by a stain removal system as described above.
As directly reflected by above description, the method of treating a stained area 102 on a cloth 103 by a stain removal system includes an initial step 1100 of retrieving (or receiving) the bleach chemical from a container, the container being in the form of a removable cartridge.
The method further comprises the steps of:

carrying 1101 a bleach chemical under a liquid form to the stained area,
generating 1102 a light radiation over the stained area.

The above embodiments as described are only illustrative, and not intended to limit the technique approaches of the present invention. Although the present invention is described in details referring to the preferable embodiments, those skilled in the art will understand that the technique approaches of the present invention can be modified or equally displaced without departing from the protective scope of the claims of the present invention. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. Any reference signs in the claims should not be construed as limiting the scope.

Claims

A stain removal system (101, 201, 301, 401, 501, 901, 1001) for treating a stained area (102) on a cloth (103), the stain removal system comprising:
- a container (104, 204, 404, 504, 504b) for containing a bleach chemical, wherein the container is a removable cartridge (404);

- a system (105, 202, 302, 505a, 505b) for carrying the bleach chemical to the stained area under a liquid form; and

- a light source (106) for generating light radiation (107) over the stained area (102).
Stain removal system as claimed in claim 1, wherein said light source (106) is a light emitting diode (LED).
Stain removal system as claimed in any one of the preceding claims, wherein said light source (106) is adapted to generate said light radiation (107) in a blue spectrum.
Stain removal system as claimed in any one of the preceding claims, wherein said light source (106) has a power larger than 50mW, preferably larger than 500mW.
Stain removal system as claimed in any one of the preceding claims, wherein the light source (106) is arranged at a front end (FE) of the stain removal system.
Stain removal system as claimed in any one of the preceding claims, wherein the distance (d1) between center central part (CP) of the light source (106) and center central part of the front end (FE) of the system has a value less than 10 cm, preferably less than 5 cm.
Stain removal system as claimed in any one of the preceding claims, wherein said system for carrying the bleach chemical comprises:
- a tube (202) and a valve (203) arranged along said tube (202), and

- a tube (202) and a pump (302) arranged along said tube (202).
Stain removal system as claimed in any one of the preceding claims, wherein said container is adapted to contain a liquid bleach chemical or a solid bleach chemical.
Stain removal system as claimed in claim 8, wherein said container is adapted to contain a solid bleach chemical, and wherein said system further comprises a water reservoir (503) and a water path (505a, 505b) for carrying water into the container to dissolve the solid bleach chemical.
Stain removal system as claimed in claim 9, further comprising a heating system for heating water of said water reservoir (503), said heating system being taken among:
- a heater (508) in thermal contact with the water reservoir (503), and

- a water channel (801) formed in a heat sink (802) of said light source (106).
Stain removal system as claimed in any one of the preceding claims, further comprising a heating system (902) for heating the stained area (102), said heating system being taken among a heater fan (902) and an infra-red lamp (1002).
Stain removal system as claimed in any one of the preceding claims, corresponding to a portable cordless device.
Cartridge forming a container for containing a bleach chemical, the cartridge being adapted to cooperate with a stain removal system as claimed in any one of the claims 1 to 12.
Method of treating a stained area (102) on a cloth (103) by a stain removal system, the method comprising the steps of:
- retrieving (1100) a bleach chemical from a container, the container being in the form of a removable cartridge,

- carrying (1101) the bleach chemical under a liquid form to the stained area,

- generating (1102) a light radiation over the stained area.