CN113164003A

CN113164003A - Method for removing stains during cleaning cycle of household appliance

Info

Publication number: CN113164003A
Application number: CN201980076388.4A
Authority: CN
Inventors: A·凯斯勒; A·迪特里希; T·尤克尔; T·巴斯蒂格凯特; T·多林
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 2018-11-23
Filing date: 2019-11-21
Publication date: 2021-07-23
Also published as: EP3656272A1; WO2020104611A1; KR20210093902A; EP3883448A1; US20220000329A1

Abstract

A method of removing stains, in particular tea stains, during the cleaning cycle of a domestic appliance, such as a dishwasher. The cleaning cycle includes at least one main wash cycle. The detergent is released during the main wash cycle when the temperature inside the household appliance exceeds a predetermined temperature threshold during the main wash cycle, wherein the predetermined temperature threshold is higher than 40 ℃, such as higher than 55 ℃.

Description

Method for removing stains during cleaning cycle of household appliance

Technical Field

The present invention relates to the field of cleaning procedures and more particularly to a method enabling optimal removal of stains arranged on objects, such as cups, inside a household appliance, such as a dishwasher. The method of the present invention is particularly suitable for removing tea stains from cups without the use of bleaching agents.

Background

Household appliances are used to clean stains on textiles, which are usually cleaned in washing machines, or on objects, such as dishes, cups or other dishes, which are usually cleaned with a dishwasher. Washing machines and dishwashers are very convenient devices that allow users to save time compared to manual cleaning, while obtaining a satisfactory level of cleanliness in a more environmentally friendly manner.

When cleaning textiles in a washing machine or dishes in a dishwasher, the user wants to remove all stains. In general, a suitable program can be selected on the machine depending on the degree of soiling of the objects to be cleaned or the total load inside the machine.

In dishwashers, it is generally possible to choose between intensive washing programs or more economical programs, each of which generally differs in terms of maximum temperature, duration, amount and type of detergent used.

A typical cleaning cycle in a dishwasher comprises a first "main wash" cycle during which detergent is released within the first few minutes after filling the dishwasher with water. The temperature will typically rise to over 40 ℃. After this main wash cycle one or more rinse cycles are carried out until the end of the cleaning cycle, which leaves the objects in the dishwasher dry.

Generally, dishwashing involves the use of a cleaning agent, such as a dishwashing liquid, a tablet or a sachet. The detergent may be dispensed either by a dispensing unit being an integral part of the household appliance or by a removable device separate from the household appliance and placed in the cavity of the household appliance. In the cleaning cycle, the first enzyme phase is typically dispensed within the first few minutes of the main wash cycle, followed by the alkaline agent after a few minutes. These cleaners are typically used at temperatures below 35 ℃ during the early stages of the cleaning cycle, and therefore their action on removing soils and stains may be longer throughout the cleaning cycle. In the final rinse cycle, a third cleaner (often referred to as a finish) is sometimes further used.

While the cleaning program is usually well-set and most stains can be eliminated by adjusting the temperature, the dosage of the cleaning agent and the duration of the cleaning cycle, it is difficult to remove some stains without returning to very high temperatures or dosages of cleaning agent. This is the case, for example, with tea stains on ceramic cups, where the best results are obtained with bleaches. However, bleaching agents are not always compatible with other items loaded inside the household appliance. Furthermore, liquid bleach-containing detergents are generally unstable and unsuitable for use in household appliances, in particular for storing them in cartridges or bags of removable or non-removable dosing systems.

For the foregoing reasons, there is a need for a method of more effectively removing stains during the cleaning cycle of household appliances.

Disclosure of Invention

In order to meet the above need, the present invention provides a method of removing stains in a cleaning cycle of a household appliance, the cleaning cycle comprising at least a main wash cycle, the method comprising:

-releasing an amount of main detergent during a main wash cycle when the temperature inside the household appliance exceeds a predetermined temperature threshold during the main wash cycle, wherein the predetermined temperature threshold is higher than 40 ℃.

Furthermore, the first detergent is released at a temperature below 40 ℃ during said main wash cycle.

The method of the present invention is particularly suitable for use in a dishwasher and is effective in removing persistent stains such as tea stains which are typically formed on ceramic dishware. The present invention successfully removes these stains without the use of bleach and without the need to use large amounts of cleaner or very high temperatures (above 70 ℃) during the cleaning cycle.

Surprisingly, it has been observed that by dispensing the alkaline phase at higher temperatures in the main wash cycle, stains which are difficult to remove, such as tea stains, can be effectively removed. In the prior art method, when the temperature inside the machine hardly exceeds 30 ℃, the detergent is dispensed in the main wash cycle very early at the beginning of the main wash. However, when the detergent is applied only at a relatively high temperature of more than 40 ℃, the combined action of the temperature and the cleaning action of the active ingredient contained in the main detergent improves the cleanliness of the object to be cleaned.

The "main wash" cycle refers to the period during which the active detergent is released. Other detergents, especially finishes, may be further released in subsequent rinse cycles.

The combination of dosing the first detergent (e.g. a detergent comprising an enzyme) at a temperature below 40 ℃ with dosing the main detergent comprising e.g. a base at a temperature above 40 ℃ results in an improved cleaning effect.

According to one embodiment, the predetermined temperature threshold may be selected among one of the following values: 50 ℃,55 ℃, 58 ℃,60 ℃, the maximum temperature reached in the main wash cycle before the temperature drop, 95% of the maximum temperature reached in the cleaning cycle.

It has been observed that the above effect is particularly enhanced for the above temperature threshold. If the machine is running a program that does not reach a temperature above 50℃, the main detergent can be dispensed before it is lowered again when the temperature inside the machine reaches the maximum temperature. The determination of the temperature may for example be done by a temperature sensor located on the dosing device or somewhere inside the machine. The times to reach these temperatures can also be estimated from a database describing the machine running program. Such a database may be provided by the manufacturer, may be determined based on previously run programs, or may be found through an external source (e.g., a network).

According to one embodiment, the primary cleaning agent may comprise a base.

The term "base" encompasses detergents with a pH value above 7. More particularly, it targets detergents with pH higher than 8, and preferably detergents with strong alkalinity with pH higher than 10.

According to one embodiment, the method may further comprise:

-releasing the first detergent at a temperature below 40 ℃ in the main wash cycle;

-releasing the primary detergent at least 5 minutes after the start of the release of the first detergent.

The main detergent may further benefit from dispensing the first detergent at an earlier stage of the main wash at a lower temperature. The first cleaning agent typically comprises an enzymatic phase. By delaying the release of the alkaline phase, the efficiency of the cleaning cycle can be further increased. The timing of the release of the primary cleaning agent may be related to the heating rate inside the household appliance. Dispensing of the main detergent may also begin at least 2 minutes after the end of the release of the last portion of the first detergent.

According to one embodiment, the method may further comprise:

-releasing a first detergent comprising an enzyme at a temperature below 40 ℃ in a main wash cycle;

-releasing the second cleaning agent after the first cleaning agent has been released.

In this case, the main detergent is released at a higher temperature in addition to another detergent or the like released at an earlier stage of the main washing cycle. This mode can be realized when the household appliance, in particular a dishwasher, runs a pre-stored cleaning program and adds only one additional step, namely the supplementary release of a quantity of main detergent at a higher temperature, outside the standard operation of the selected pre-stored cleaning program. Alternatively, both the first and second cleaning agents may be enzymes, e.g., the same type of enzyme, that are released at different times during the cleaning cycle. For example, the first detergent may be released during a pre-wash of the cleaning cycle, while the second detergent may be released during a main wash of the cleaning cycle.

According to one embodiment, the primary cleaning agent may comprise at least one chelating agent.

According to one embodiment, the primary detergent may comprise at least one first chelating agent and at least one second chelating agent.

Preferably, the first and second chelating agents have different properties. It has been found that chelating agents are capable of interacting with soils such as tea stains, especially at temperatures above 50 ℃, thereby improving the efficiency of the cleaning cycle in a dishwasher.

The combined effect of two chelating agents having different properties, for example, the use of a chelating agent such as citrate, phosphonate or tartrate in combination with other chelating agents such as methylglycinediacetic acid (MGDA), ethylenediamine-N, N' -disuccinic acid (EDDS), tetrasodium-N, N-bis (carboxymethyl) -L-glutamic acid or N, N-dipropyl-2, 3-dihydroxyterephthalamide, further enhances the cleaning effect at temperatures above 40 ℃.

According to one embodiment, the first chelating agent may be selected from citrate, phosphonate or tartrate, and the second chelating agent may be selected from methylglycinediacetic acid (MGDA), ethylenediamine-N, N' -disuccinic acid (EDDS), tetrasodium-N, N-bis (carboxymethyl) -L-glutamic acid or N, N-dipropyl-2, 3-dihydroxyterephthalamide.

According to one embodiment, the first detergent may be dosed at a ratio between 0.1 and 10 times the amount of the second detergent relative to the second detergent.

For example, both the first detergent and the second detergent may be enzymes, typically, but not necessarily, the same type of enzyme. The first detergent may be dosed at 3/5 and the second detergent may be dosed at 2/5 of the total amount of released enzyme. By dispensing the enzyme at two different times of the cleaning cycle, better overall cleanliness results can be observed at the end of the cleaning cycle of the household appliance. Alternatively, the first detergent may be an enzyme and the second detergent an alkali. When dispensing the main detergent, care should be taken to adjust the alkalinity inside the household appliance.

According to one embodiment, the method may further comprise:

-determining the amount of primary detergent to be released based on the value of said predetermined temperature threshold, the amount of primary detergent being higher when the predetermined temperature threshold is lower.

It has been observed that there is a correlation between the amount of main detergent released and the cleanliness of the cleaned object during the cleaning cycle of the household appliance. For a predetermined temperature threshold set above 55 ℃, the dose of primary detergent may be set to a lower value, for example between 15 and 25 grams. For a predetermined temperature threshold of 40 ℃, the dose of primary detergent may advantageously be set to a higher value, for example between 25 and 40 grams.

According to one embodiment, the amount of primary detergent to be released may be between 3 and 40 grams.

According to one embodiment, the method may further comprise:

-obtaining information about the internal temperature of the household appliance at different times of the cleaning cycle.

The temperature inside the household appliance can be measured using sensors at regular time intervals or estimated based on the temperature variation of the cleaning program the machine is running. This information need not necessarily be the temperature itself, but may be a relevant parameter that can determine the temperature inside the machine. For example, it may be the setting of a heating unit inside the machine, the tension or current measured on such a heating unit, information provided by external sensors or manually by a user or information obtained from a remote source (e.g. a network). The household appliance (dishwasher) may also communicate temperature measurements made inside the household appliance to the dosing device, for example, through an "API" (e.g., "application programming interface").

According to one embodiment, information about the temperature inside the household appliance at different times of the cleaning cycle may be provided by a temperature sensor.

According to one embodiment, the information about the temperature inside the household appliance at different times of the cleaning cycle can be provided by a database of programs run by the household appliance.

The sampling rate of the query (or just its reception) of such temperature-related information may occur, for example, at a frequency in the range of 0.01Hz to 1 kHz.

According to one embodiment, the method may further comprise:

-releasing a quantity of primary cleaning agent from a removable dosing device located inside the household appliance.

The removable dosing device may be, for example, an automated unit comprising cartridges containing different cleaning agents and a dispensing unit capable of releasing controlled amounts of cleaning agents at controlled times. Different types of hardware may be part of the dosing device for controlling the dispensing of the cleaning agent or for communicating with external devices, such as a data processing unit, a user-operable household appliance or a mobile device or server.

According to one embodiment, the method may further comprise:

-releasing a quantity of primary detergent from a chamber configured to contain detergent in the household appliance.

According to one embodiment, the method may further comprise:

-acquiring information related to the presence of tea stains between objects arranged inside the household appliance.

For example, the presence of a mug or cup inside the machine can be evaluated based on a particular vibration signal during loading inside the machine. Turbidity of the water during the cleaning cycle or a specific marker recognizable by the biosensor may also be used to determine the presence of tea stains. Otherwise, the user can select a special program or an option in a program that parameterizes the household appliance to implement the method of the present invention. Such a selection may also be considered as "information about the presence of tea stains" or a hypothesis thereof. The program may be selected by pressing a button on the machine or may be selected in a menu selectable on the machine or on a human-machine interface enabling the setting of programs on the household appliance. The user may set a "tea stain" cleaning option for the currently selected program in the home appliance or through a removable device or server (e.g., "app").

The invention also relates to a system for removing stains in a cleaning cycle of a household appliance, the cleaning cycle comprising at least a main wash cycle, the system comprising:

-a non-transitory data processing unit configured to acquire information about the internal temperature of the household appliance at different times of the cleaning cycle;

-a dosing device containing a main detergent and capable of receiving information from the non-transitory data processing unit, the dosing device being configured to release a first detergent in the main wash cycle at a temperature below 40 ℃ and to release an amount of main detergent in the main wash cycle at a time provided by the non-transitory data processing unit, the time being associated with a temperature inside the household appliance exceeding a predetermined temperature threshold in the main wash cycle, wherein the predetermined temperature threshold is above 40 ℃.

Such a system may be implemented in different forms. The non-transitory data processing unit may be a piece of dedicated hardware placed on the dosing device (e.g. in case the dosing device is a removable automatic dosing device to be placed inside the household appliance). It may also be a separate device incorporated into the household appliance or removably placed inside or outside the household appliance. The non-transitory data processing device may also be part of another device, such as a removable device, a smartphone, a tablet, a computer, a server.

According to one embodiment, the dosing device may be a removable dosing device configured to be positioned inside the household appliance.

The invention also relates to a non-transitory computer-readable storage medium on which a computer program is stored, the computer program comprising instructions for carrying out the method for removing stains in a cleaning cycle of a domestic appliance as described above.

In other words, the invention also relates to a computer program product comprising instructions for carrying out the method for removing stains in a cleaning cycle of a domestic appliance as described above.

Drawings

The present disclosure will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and:

FIG. 1 illustrates a set of devices that may be used to implement a method in accordance with an exemplary embodiment;

FIG. 2 shows a schematic diagram of components that may be part of a system according to an embodiment;

FIG. 3 illustrates a simplified workflow of a method according to an exemplary embodiment;

fig. 4-8 show 5 examples of graphs of the internal temperature of a dishwasher over time during a cleaning program.

Detailed Description

The present invention relates to a method that provides a more efficient and economical means of removing stubborn stains such as tea stains that can typically be found on ceramics (cups) without the use of bleach.

To this end, the invention delays the dispensing of detergent during the main wash cycle of the household appliance until the temperature reaches a predetermined temperature threshold.

The method can be applied to various household appliances, but is particularly effective for removing stains during the cleaning cycle of a dishwasher.

Fig. 1 shows an environment 1 in which an electric household appliance 300 may receive a detergent dispensed from a dosing device 200, the dosing device 200 being configured to dispense the detergent during a cleaning cycle of the electric household appliance. A removable device 400, such as a cell phone, tablet computer or any other computer or similar device, may further interact with the dosing device 200 and/or the household appliance 300. The removable device 400 may for example be used for setting parameters for dispensing a cleaning agent or for selecting a cleaning program from programs that may be run on the household appliance 300. The removable device 400 may further receive information from or send information to the dosing device 200 and/or the household appliance 300. For example, the movable device may provide the household appliance 300 and/or the dosing device 200 with information about the status of objects inserted inside the household appliance 300, such as the nature of these objects, the presence of stains, such as tea stains, the type of stain and the degree of soiling of the inserted object.

The dosing device 200 may be a separate device as shown in fig. 1, comprising a plurality of cartridges with different detergents (e.g., enzyme-containing liquid, alkali-containing liquid, and finish) and a dispensing unit coupled to the cartridges. The dosing device may also be an integral part of the household appliance 300, for example a dosing chamber thereof.

Fig. 2 schematically illustrates a system 22 that may be used to implement the method of the present invention. The system comprises the dosing device 200 and the non-transitory data processing unit 20 already described in connection with fig. 1. The non-transitory data processing unit 20 processes information about the temperature inside the household appliance 300 and communicates with the dosing device 200 to indicate when to dispense an amount of main detergent or any other detergent. The non-transitory data processing unit 20 may also indicate the amount of detergent to be released by the dosing device 200. The non-transitory data processing unit 20 may be an integral part of the dosing device 200 or a separate element. The non-transitory data processing unit 20 may also be part of the household appliance 300, for example, inside the removable device 400 or part of another element that is able to communicate with the dosing device 200.

The non-transitory data processing unit 20 may generally include at least one processor 212, a storage element 211 (e.g., a hard disk drive or volatile memory, such as random access memory), an interface 213 capable of displaying information to a user and/or receiving input from a user and optionally a sensor 214. The memory element 211 may be used, for example, to download information from the network, to store information transmitted by the removable device 400 or received via the interface 213, for example. It may also comprise pre-stored information, for example about the programs run by the household appliance 300, in particular the temperature variation over time inside the household appliance 300. The received or already stored information may be stored in the memory element 211. The sensor 214 may be a device, such as a temperature sensor, capable of determining the temperature inside the household appliance 300 during a cleaning cycle. The non-transitory data processing unit 20 may also include other sensors (instead of or in addition to temperature sensors), such as timers, accelerometers, spectrometers, pH meters, conductivity measurement sensors, turbidity measurement sensors.

The information about the temperature inside the household appliance 300 may be transmitted to the non-transitory data processing unit 20 via an external source, such as an external sensor located in the household appliance 300, or by accessing a database comprising information about the temperature inside the household appliance 300 at different times of the cleaning cycle.

Information may be transferred between the non-transitory data processing unit 20 and the dosing device 200 and/or the household appliance 300 and/or the mobile device 400 via a wired or wireless connection. Wireless communication may be implemented using, for example, Radio Frequency Identification (RFID), Near Field Communication (NFC), bluetooth, Wireless Local Area Network (WLAN), thread, Zigbee.

The system 20 described above can generally be used to implement the improved stain removal method of the present invention. The stain removal method comprises delaying the dispensing of a primary detergent, typically comprising lye, in a primary wash cycle of a cleaning cycle of the household appliance 300. Maximum efficiency is observed when the main detergent is not dispensed at the beginning of the main wash cycle but when a predetermined temperature threshold is exceeded, for example a temperature threshold higher than 40 ℃.

Fig. 3 shows an example of a method 30 for removing stains in a cleaning cycle of a household appliance, the method comprising obtaining information 31 about the temperature inside the household appliance 300 at different times of the cleaning cycle. This information may be provided by the sensor 214 or may be read in a database comprising a record or estimate of the temperature inside the household appliance 300 over time.

The method is performed by early release of a first detergent 32, typically comprising enzymes, during a main wash cycle, at a temperature inside the household appliance 300, typically below 30 ℃.

Then, when the temperature inside the household appliance 300 exceeds 40 ℃, the method proceeds by releasing a quantity 33 of the main detergent (generally a detergent comprising an alkali). The moment when such conditions are fulfilled can be determined using the measured temperature or by estimation based on knowledge of the temperature inside the household appliance over time.

It should be noted that the release may increase when the predetermined temperature threshold is close to 40 deg.c, whereas the release may decrease if the predetermined temperature threshold is close to 55 deg.c, advantageously higher than 58 deg.c.

The predetermined temperature threshold may be set to a fixed value (e.g., 40 deg.C, 50 deg.C, 55 deg.C, 58 deg.C, or 60 deg.C), or dynamically associated with events observed during the cleaning cycle. For example, once the temperature within the household appliance 300 reaches a maximum and begins to decrease, the dispensing of the primary detergent may begin. If the database contains expected or predicted temperature changes over time inside the household appliance 300, the conditions for dispensing the main detergent may be set to a temperature exceeding a certain percentage of the maximum temperature corresponding to the maximum temperature in the main wash cycle, e.g. 80% or 90% or 95% of the maximum temperature value, or the expected time at the expected temperature. In that case, a timer may be used to trigger the dispensing of the primary detergent.

Another possibility is to further set the time separating the start of the main cycle from the release of the main detergent. For example, it may wait 5 or 10 minutes after the main wash cycle begins, or wait 5 or 10 minutes after the first detergent begins to be dispensed in the main wash cycle and then release the main detergent.

Generally, the amount of main detergent released during the main wash cycle may be between 3 and 40 grams, depending on the degree of soiling inside the household appliance 300 and the load of the objects and the selected predetermined temperature threshold.

According to another embodiment, an amount of primary detergent may also be dispensed outside the normal cleaning cycle when the temperature inside the household appliance 300 exceeds a predetermined temperature threshold. In this case, the first detergent, which normally contains the enzyme phase, can be dispensed within the first few minutes of the main wash cycle, and then within the next ten minutes the second detergent, which normally contains the base, is released, while the temperature is still below 40 ℃, and then a much smaller amount of the main detergent can be dispensed inside the household appliance at a higher temperature above 40 ℃ than in the above example.

The above method may be stored in a cleaning program of the home appliance 300 and prepared to be selected by a user. It can also be added as an option to any procedure of the household appliance, for example as a decontamination option, particularly suitable for removing tea stains, in particular in a dishwasher. The user may make a decision to run a cleaning program comprising the above-described method. The user selects such a special program or option, either on the household appliance 300 or via any other interface, for example on the removable device 400. Alternatively, the dosing device 200 or the non-transitory data processing unit 22 may decide to carry out the method of the invention based on, for example, information about the presence of difficult to remove stains, such as tea stains.

The cleaning strategy may also be adjusted when such difficult to remove stains are determined to be present or in the event that an external source (e.g., a user) indicates that such stains may be present. If the preselected program does not reach a temperature above 40 c, the main cleaning cycle can be adjusted to encompass a shorter time frame during which the temperature exceeds 40 c (advantageously 55 c or higher) to dispense the main cleaning agent at such higher temperatures.

The control of the household appliance using the above method may be provided in the form of an application program on, for example, a mobile phone, or in the form of a computer program loaded into any electronic device capable of communicating with the household appliance and updating its program.

Fig. 4 to 8 provide 5 examples of cleaning cycles of different dishwasher interiors that benefit from the above method of cleaning stains. In the example provided below, 102 objects, including various articles and soil types, are placed within the dishwasher.

The articles comprise a knife, a teaspoon, a big soup spoon, a salad bowl, a pan, a cup, a mug, a cup mat, a plate, a screen, a small shovel, a soup ladle, a pot, a glass bowl, a chopping board, a fork and a pot.

These articles provide a good example of the types of surfaces that may be found in dishwasher cleaned articles. The types of stains found in these 102 items were as follows: yolk, spinach, tea, milk, minced meat, oatmeal, egg and baked broadbean noodles.

The distribution of the items and the dirt is in accordance with the european norm EN 50242 for testing the efficiency of the cleaning procedure. In addition to the limitations set by this specification, dishwashers are also loaded with different types of materials, such as glass, ceramic or plastic articles (e.g. plastic tanks).

To test the effectiveness of the cleaning strategy employed, cups containing tea stains were graded from 0 to 10 in cleanliness, with 10 being associated with a perfect cleaning effect. In the following example, the grade provided to the tea stain is the average obtained in 6 cups inserted in the dishwasher. The overall cleanliness ratings for all articles are 0 to 5, with a rating of 5 being associated with a perfectly clean group of articles. The presence of droplets is also assessed using a method that includes counting the presence of droplets on the cleaning article. The scale goes from 0 (no droplets found) to 6 (6 or more droplets found).

Figure 4 shows the temperature change over time for the whole cleaning cycle of the MIELE G6730SC dishwasher. The selected program represented on FIG. 4 is labeled "QUICK POWER WASH 60 ℃". The graph of fig. 4 includes a vertical temperature axis 408 and a horizontal time axis 409. The cleaning procedure can be broken down into 6 cycles: the dishwasher is filled 401 with water, a main wash cycle 402, a first water exchange cycle 403, a first rinse cycle 404, a second water exchange cycle 405 and a final rinse cycle 406.

During the main wash cycle, the temperature inside the dishwasher rises to approximately 65 ℃. The dispensing of the cleaning agent includes: the first detergent 410 is released at the beginning of the main wash cycle, the finish 430 is released in the final rinse cycle, and the main detergent 420 is released in the main wash cycle.

Figure 4 shows 4 different occasions, labeled 2a-2d, for releasing the primary cleaning agent 420. The dispensing of the main detergent 420 is performed after a delay of more than 10 minutes after the dispensing of the first detergent 410. Theoretically, a delay 440 of about 7 minutes may also result in satisfactory results.

The first test was performed using the classic "QUICK POWER WASH 60 ℃ cycle of a dishwasher. The normal cycle includes releasing the primary detergent 2 minutes after dispensing the first detergent 410. Table 1 below summarizes the results observed after this normal cleaning cycle. Repeat twice with different doses of the first detergent (enzyme phase), the main detergent (alkaline phase) and the finish.

TABLE 1

As shown in table 1, the normal cleaning cycle of the dishwasher did not reach a satisfactory level of tea stain removal. In the case of high doses of detergent, the results remained below 9(9 is considered to be a satisfactory grade above which the user does not notice any tea stains on the cup).

Table 2 below provides the results observed when the main detergent 420 was dispensed at a higher temperature for more than 10 minutes after dispensing the first detergent 410. Both tests 4 and 5 were done with dispensing the main detergent at a temperature T above 60 ℃. Test 4 was done with a normal dose of main detergent, while test 5 was done with a higher dose of detergent than test 4.

TABLE 2

Table 2 shows that dispensing the main cleaner 420 at a regular dose at a temperature above 55 ℃ is able to perfectly remove tea stains. It further indicates that if the temperature threshold for dispensing the main cleaner is above 55 ℃, the dose has no significant effect on the cleanliness results.

Further testing tends to confirm these observations.

Figure 5 shows the temperature as a function of time throughout the cleaning cycle of an AEG FS56302WO dishwasher running a 60 minute program. The graph of fig. 5 includes a vertical temperature axis 408 and a horizontal time axis 409. The cleaning procedure can be broken down into 4 cycles: the dishwasher is filled 501 with water, a main wash cycle 502, a first water exchange cycle 503 and a final rinse cycle 504.

The dispensing of the cleaning agent includes: the first detergent 510 is released at the beginning of the main wash cycle, the finish 530 is released in the final rinse cycle, and the main detergent 520 is released in the main wash cycle.

Fig. 5 shows 4 different occasions, labeled 2 and 2a-2c, for releasing the primary cleaning agent 520. The "classic" or "normal" timing for dispensing the primary detergent corresponds to reference numeral 2 and is labeled 550. The dispensing of the main detergent 520 is performed after a delay of more than 10 minutes after the dispensing of the first detergent 510. Theoretically, a delay 540 of about 7 minutes may also lead to satisfactory results.

Table 3, shown below, provides the results observed when the primary cleaning agent 520 was released at different times 2, 2a-2c as shown in FIG. 5. For release times 2 and 2c, normal and higher doses of detergent were tested.

TABLE 3

The table confirms the observations made in connection with fig. 4. Furthermore, although not shown in table 3, it has been found that an increase in the amount of primary cleaning agent dispensed even at lower temperatures below 55 ℃ but above 40 ℃ can result in very satisfactory removal of tea stains of high cleanliness grade.

Fig. 6 shows the temperature as a function of time during the entire cleaning cycle of a Bosch SMS68TW06E dishwasher running a short one hour program with a drying cycle of 1 hour. The graph of fig. 6 includes a vertical temperature axis 408 and a horizontal time axis 409. The cleaning procedure can be broken down into 6 cycles: the dishwasher is filled 601 with water, a main wash cycle 602, a first rinse cycle 603, a final rinse cycle 604, a zeolite drying cycle 605 and a drying cycle 606.

The dispensing of the cleaning agent includes: the first detergent 610 is released at the beginning of the main wash cycle and the main detergent 620 is released during the main wash cycle.

Fig. 6 shows 3 different occasions, labeled 2, 2a, 2b, for releasing the primary cleaning agent 620. The "classic" or "normal" timing for dispensing the main cleaner corresponds to reference numeral 2 and is labeled 650.

Table 4, shown below, provides the results observed when the primary cleaning agent 620 was released at different times 2, 2a-2b, as shown in FIG. 6.

TABLE 4

The table confirms the observations made in connection with fig. 4 and 5. Furthermore, although not shown in table 4, it has been found that an increase in the amount of primary cleaning agent dispensed at 40 ℃ may also result in very satisfactory removal of tea stains of high cleanliness grade.

Fig. 7 shows the temperature over time during the entire cleaning cycle of a Bosch SMS68TW06E dishwasher running a long two-hour program with a drying cycle of 1 hour. The graph of fig. 7 includes a vertical temperature axis 408 and a horizontal time axis 409. The cleaning procedure can be broken down into 5 cycles: the dishwasher is filled 701 with water, a main wash cycle 702, a first rinse cycle 703, a final rinse cycle 704, and a dry cycle 706.

The dispensing of the cleaning agent includes: the first detergent 710 is released at the beginning of the main wash cycle and the main detergent 720 is released during the main wash cycle.

Fig. 7 shows two different occasions, labeled 2, 2a, for releasing the primary cleaning agent 720. The "classic" or "normal" timing for dispensing the primary detergent corresponds to reference numeral 2 and is labeled 750.

Table 5, shown below, provides the results observed when the primary cleaning agent 720 was released at different times 2, 2a as shown in fig. 7.

Tests

1 and 2 were performed with a normal dose of detergent, while tests 3 and 4 were performed with a higher dose of detergent than

tests

1 and 2.

TABLE 5

The table confirms the observations made in connection with figures 4, 5 and 6. Furthermore, it can be seen that the dosage of detergent is the second means to act on the tea stain removal, the result of which is synergistically combined with the temperature at which the alkaline main detergent 720 is dispensed.

Another observation, which was made but not shown in fig. 7, is that by splitting the partition of the enzyme phase into two separate phases, the overall cleanliness can be further improved. A first portion of the enzyme phase, for example 3/5 of the total amount of enzyme phase, may be dispensed at the beginning of the cleaning cycle, either during the pre-wash cycle or the first few minutes of the main wash cycle. A second amount of enzyme phase, e.g., 2/5 of the total amount of enzyme phase, may be dispensed at a later stage of the cleaning cycle, e.g., about 10 minutes after the first amount is dispensed.

Figure 8 shows the temperature over time for the Bauknecht BFE 2B19 dishwasher running a short time boost program with a drying cycle throughout the cleaning cycle. The graph of fig. 8 includes a vertical temperature axis 408 and a horizontal time axis 409. The cleaning procedure can be broken down into 6 cycles: the dishwasher is filled 801 with water, a main wash cycle 802, a first rinse cycle 803, a second rinse cycle 804, a final rinse cycle 805 and a drying cycle 806.

The dispensing of the cleaning agent includes: the first detergent 810 is released at the beginning of the main wash cycle and the main detergent 820 is released during the main wash cycle.

Fig. 8 shows two different occasions, labeled 2, 2a, for releasing the primary detergent 820. The "classic" or "normal" timing for dispensing the primary cleaner corresponds to reference numeral 2 and is labeled 850.

Table 6 shown below provides the results observed when the primary detergent 820 is released at different times 2, 2a as shown in fig. 8.

TABLE 6

The table confirms the observations made in connection with fig. 4-7. It is further demonstrated that the dosage alone is not sufficient to perfectly remove tea stains, but can be achieved by a synergistic effect of the timing of the dispensing of the main detergent 820 and the dosage of detergent.

Although not shown in the above example, it is also possible to dispense the main detergent twice in the calculated amount, once at the beginning of the main wash cycle in the "normal" release of detergent, and then a second dispensing of the main detergent at a higher temperature.

The steps of the above examples and embodiments may be implemented by a processor, such as a computer. A computer program product comprising the steps of the above method may be used to implement the method on a computer.

A computer program comprising instructions for implementing the method of the invention may be stored on different non-transitory computer-readable storage media. For example, they may include a processor or chip, an FPGA (field programmable gate array), an electronic circuit containing multiple processors or chips, a hard drive, a flash or SD card, a USB memory stick, a CD-ROM or DVD-ROM or Blu-ray disc, or a floppy disc 216.

While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the various embodiments in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments as contemplated herein. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of various embodiments as set forth in the appended claims.

Claims

1. Method for removing stains in a cleaning cycle of a household appliance (300), the cleaning cycle comprising at least a main wash cycle (402,502,602,702,802), the method comprising:

-releasing a first detergent (410,510,610,710,810) at a temperature below 40 ℃ during a main wash cycle;

-releasing an amount of main detergent (420,520,620,720,820) during the main wash cycle when the internal temperature of the household appliance exceeds a predetermined temperature threshold during the main wash cycle, wherein the predetermined temperature threshold is higher than 40 ℃.

2. The method of claim 1, wherein the predetermined temperature threshold is selected in one of the following values: 50 ℃,55 ℃, 58 ℃,60 ℃, the maximum temperature reached in the main wash cycle before the temperature drop, 95% of the maximum temperature reached in the cleaning cycle.

3. The method of any of the above claims, wherein the primary cleaner comprises at least one chelating agent selected from the group consisting of: citrate, phosphonate, tartrate, methylglycinediacetic acid (MGDA), ethylenediamine-N, N' -disuccinic acid (EDDS), tetrasodium-N, N-bis (carboxymethyl) -L-glutamic acid, or N, N-dipropyl-2, 3-dihydroxyterephthalamide.

4. The method of any of the preceding claims, further comprising:

-releasing the primary detergent at least 5 minutes after starting the release of the first detergent.

5. The method of any of the preceding claims, further comprising:

-releasing a first detergent comprising an enzyme at a temperature below 40 ℃ in the main wash cycle;

-releasing a second cleaning agent (450,550,650,750,850) after initiating the release of the first cleaning agent.

6. The method of claim 5, wherein the first cleaner is dosed at a ratio between 0.1 and 10 times the amount of the second cleaner relative to the second cleaner.

7. The method of any of the preceding claims, further comprising:

-determining the amount of primary detergent to be released based on the value of said predetermined temperature threshold, the amount of primary detergent being higher when said predetermined temperature threshold is lower.

8. The method of any of the above claims, wherein the amount of primary detergent to be released is between 3 grams and 40 grams.

9. The method of any of the preceding claims, further comprising:

-obtaining information about the internal temperature of the household appliance at different times of said cleaning cycle.

10. Method according to claim 9, wherein the information about the internal temperature of the household appliance at different times of the cleaning cycle is provided by means of a database of programs that can be run by the household appliance.

11. The method of any of the preceding claims, further comprising:

-releasing a quantity of said primary cleaning agent from a removable dosing device (200) located inside said household appliance.

12. The method of any of the preceding claims, further comprising:

13. System (22) for removing stains in a cleaning cycle of a household appliance (300), the cleaning cycle comprising at least a main wash cycle (402,502,602,702,802), the system comprising:

-a non-transitory data processing unit (20) configured to acquire information about the internal temperature of the household appliance at different times of the cleaning cycle;

-a dosing device (200) containing a main detergent (420,520,620,720,820) and capable of receiving information from the non-transitory data processing unit, the dosing device being configured to release a first detergent (410,510,610,710,810) in the main wash cycle at a temperature below 40 ℃ and to release an amount of main detergent in the main wash cycle at a time provided by the non-transitory data processing unit, the time being related to the temperature inside the household appliance exceeding a predetermined temperature threshold in the main wash cycle, wherein the predetermined temperature threshold is above 40 ℃.

14. The system of claim 11, wherein the dosing device is a removable dosing device configured to be located inside the household appliance.

15. A non-transitory computer readable storage medium having stored thereon a computer program comprising instructions for performing the method for removing stains in a cleaning cycle of a domestic appliance according to any one of claims 1-12.