Device with opposing features for ultrasonically cleansing hair - Patent application

Abstract

The present invention relates to a cosmetic device for cleansing hair, comprising a handpiece (18) including: an ultrasonic transmitter; and a probe (2) cooperating with a counter shaped portion (3) to clamp a strand of hair between a bearing surface (31) of the counter shaped portion (3) and a distal outer surface (22) of the probe (2). The present invention also relates to a cosmetic method for cleansing hair, using said device, preferably together with a cleansing composition comprising at least one surfactant.

Description

[Technical field]

[0001] The present invention relates to a handheld device for ultrasonically cleansing hair. The present invention also relates to a method of using said handheld device in the presence of a cosmetic composition, in particular a shampoo. [Background technology]

[0002] More generally, a cosmetic product is a product as defined in Regulation (EC) No. 1223 / 2009 of the European Parliament and of the Council of 30 November 2009 on cosmetic products.

[0003] Various devices for cleansing the hair are known.

[0004] Some documents in the hair field relate to multifunctional combs or hairbrushes with a water reservoir and an ultrasonic atomization system, such as US Pat. No. 5,399,623, US Pat. No. 5,499,637, US Pat. No. 5,499,647 or US Pat. No. 5,523,663.

[0005] Others relate to bowls or basins for cleansing the hair, such as US Pat. No. 5,399,623, US Pat. No. 5,499,637 or US Pat. No. 5,499,663.

[0006] Still other documents relate to shower devices, such as US Pat. No. 5,399,633.

[0007] US Patent No. 5,399,633 refers to the use of an emulsifier to cleanse hair extensions, which involves moving the hair strands through multiple sections that allow for washing, rinsing and then drying, respectively.

[0008] Patent Document 10 relates to a handheld device with two separate spaces for containing water and shampoo, respectively, and an ultrasonic wave emission system for washing hair. However, this device cannot easily grasp the treated portion of the hair, resulting in a lack of effectiveness and loss of surfactant solution.

[0009] Patent document 11 relates to a method for treating hair fibers by applying a cosmetic composition and by acoustic wave treatment, these two steps being separate. The document does not mention the application of ultrasound to cleanse the hair. The shampooing is only mentioned as a post-treatment of dyeing, since the two purposes are mutually contradictory, i.e. closing the scale for shampooing and opening the scale for acoustic wave treatment, and therefore it is outside the scope of acoustic wave treatment.

[0010] US Patent No. 5,399,633 relates to a system for removing parasites from hair by means of a device comprising an ultrasonic transmitter for generating ultrasonic radiation and a number of tines extending from the base of the device, the number of tines including vibrating and reflecting tines, the ultrasonic radiation being transmitted by the vibrating tines and reflected by the reflecting tines so as to damage the parasites present between these same tines. This document does not mention any use other than the removal of parasites and their larvae. In particular, it does not mention any washing of hair. Moreover, the use of the device described in this document does not involve the use of any composition, whether cosmetic or otherwise.

[0011] Patent document 13 relates to a device for damaging parasites while they are on the body surface of a mammal, comprising an ultrasonic transmitter for generating ultrasonic radiation and a handheld device coupled to said ultrasonic transmitter, suitable for being placed near the parasites and transmitting ultrasonic radiation thereto, said handheld device comprising a number of tines extending from a base of the device, and the number of tines and / or the ultrasonic transmitter comprising at least one vibrating element coupled to the number of tines. According to this document, removal of the parasites may be performed by combing or under vacuum after irradiation. No application of washing hair during irradiation is mentioned.

[0012] Patent document 14, filed by the applicant on February 28, 2020, discloses a device for applying a hair formulation, comprising an electrostatic charger electrically connected to an electrode, a body structure having one or more teeth at a front end, the tips of the teeth including an electrode, and a cartridge containing the hair formulation.

[0013] Ultrasonic treatment is only performed in the device variants with electrostatic chargers, more specifically in the nebulizer variants that generate mist from shampoo formulations. The nebulizer is located upstream of the comb teeth in the device. This mist is discharged through an orifice located at the distal end of the teeth. The nebulizer, which may include an ultrasonic generator, is located upstream of the comb teeth in the device. Therefore, ultrasonic waves are not emitted to hair.

[0014] In general, the generation of static charges on hair can reduce the effectiveness of shampoo actives by inhibiting their adsorption as a result of repulsion phenomena. If hair is negatively charged, the adsorption of anionic surfactants and anionic polymers can be limited. If hair is positively charged, the adsorption of cationic conditioning polymers can be limited. [Prior art documents] [Patent documents]

[0015] [Patent Document 1] Chinese Patent No. 105124902 [Patent Document 2] China Utility Model No. 204909967 [Patent Document 3] Japanese Patent Application Publication No. 09-308518 [Patent Document 4] Japanese Patent Application Publication No. 08-001104 [Patent Document 5] China Utility Model No. 204448700 Specification [Patent Document 6] JP 2015-019670 A [Patent Document 7] China Patent Application Publication No. 107716391 [Patent Document 8] China Utility Model No. 2191621 Specification [Patent Document 9] US Patent Application Publication No. 2018 / 207690 [Patent Document 10] China Utility Model No. 2720876 [Patent Document 11] International Publication No. 2011 / 001084 [Patent Document 12] International Publication No. 2017 / 118984 [Patent Document 13] Australian Patent No. 2012221702 [Patent Document 14] US Patent Application Publication No. 2021 / 2667344 Summary of the Invention [Problem to be solved by the invention]

[0016] There is therefore a need to provide an improved portable device for cleansing hair using ultrasound that performs well for cleansing hair and at the same time uses significantly less water and less surfactant than known devices, in particular 10 to 20 times less water than known devices, to meet current environmental requirements. For further efforts, recycling of wastewater may be envisaged. [Means for solving the problem]

[0017] The subject of the present invention is a cosmetic device for cleansing the hair, comprising: - an ultrasonic transmitter having an ultrasonic transducer powered by a current generator and configured to generate ultrasonic vibrations; - a handpiece including a probe coupled to an ultrasonic transmitter for transmitting ultrasonic vibrations generated by a transducer to a hair strand to be treated, the probe extending along a longitudinal axis X between a proximal outer surface and a distal outer surface. wherein the hand piece also includes a counter shaped portion having a bearing surface for at least partially receiving a hair strand to be treated, and the probe cooperates with the counter shaped portion to sandwich the hair strand between the bearing surface of the counter shaped portion and a distal outer surface of the probe.

[0018] The device according to the invention allows for effective cleansing of hair. Ultrasound can also contribute to the release of chemical species of the cleansing composition, such as free radicals, which contribute to a more thorough cleansing of keratinous materials. Where appropriate, under the effect of acoustic waves, the foam of the cleansing composition generates shock waves that can exert a mechanical effect on the hair, thus improving cleansing.

[0019] Advantageously, the distal outer surface of the probe is positioned "close to the surface of the hair to be cleansed."

[0020] The present invention relates to a cosmetic method for cleansing hair, comprising: (i) providing a device as aforesaid; (ii) sandwiching at least a region of the bristle bundle between a bearing surface of the opposing feature and a distal outer surface of the probe; (iii) generating ultrasonic waves; and (iv) where appropriate, after relative movement of the bundle with respect to the probe, successively treating one or more other areas to clean the desired portion of the bundle. The present invention relates to a cosmetic method comprising the steps of:

[0021] Preferably, the method comprises, during operation (iii), an operation (v) which comprises applying to the hair a metered amount of a cleansing composition, which preferably comprises at least one surfactant, in particular anionic.

[0022] Preferably, the method is performed dynamically with a speed of movement of the bundle relative to the probe of between 5 mm / s and 5 cm / s.

[0023] Advantageously, the device does not have a static charger so as not to inhibit the action of the cleansing composition and to avoid charging the hair and making it sticky.

[0024] Preferably, the opposing profile does not have a circular or semicircular cross section perpendicular to the longitudinal axis X in order to optimize the cleansing quality.

[0025] [Main definitions] A "cross-section of a component of axis X" is a cross-section perpendicular to axis X of the component.

[0026] The expression "longitudinal axis of a component" refers to a line connecting all of the centroids of the cross sections of the component.

[0027] The expression "close to the surface of the hair to be cleansed" should be understood to mean close enough that the effect of the acoustic waves has a beneficial effect on the cleansing action. For example, the distal outer surface is located less than 15 mm, more preferably less than 10 mm, even more preferably less than 5 mm, and most preferably less than 2.5 mm from the surface of the hair to be cleansed. The probe may contact the hair to be cleansed.

[0028] The expression "counter-shape" denotes an element whose shape is complementary to that of the probe and which is capable of blocking the hair between it and the probe. The counter-shape and the probe can advantageously be moved relative to each other in order to insert the hair to be treated in a position where the probe and the counter-shape are spaced apart, and then to apply pressure to the hair so as to ensure a particularly better contact between the probe delivering ultrasound and the hair in a position where the probe and the counter-shape move together or in the use position of the device.

[0029] "Ultrasound" consists of radio waves with frequencies ranging from 16KHz to 10MHz.

[0030] To generate ultrasonic or ultrasonic wave motion, a "high frequency generator" converts normal mains power frequencies of 50 Hz to 60 Hz into high frequency vibrations, preferably in the range of 16 kHz to 60 kHz.

[0031] The "ultrasonic transducer" or transducer then converts these electrical vibrations into acoustic vibrations of the same frequency. A transducer is nothing but a resonant system driven by an energy supply suited to its natural vibrations. The transducer converts the electrical energy into acoustic energy in the ultrasonic range, from a few mW to a few kW.

[0032] A "sonotrode" is a metal part or tool that is coupled to a transducer, which restores this vibrational energy in a target element, for example a hair. According to the frequency range of standard ultrasound use, the sonotrode resonates at a frequency by "contracting" and "expanding" x times per second with an amplitude of a few micrometers. This half-wavelength acoustic wave resonance follows the characteristics of the constant elasticity of the material, its density ρ, the propagation speed and frequency of sound through this material. Sonotrodes are made of titanium, aluminum or steel, with or without heat treatment. Small diameter sonotrodes are sometimes called probes. The shape of the sonotrode depends on the amount of vibrational energy and the physical constraints of the exact application.

[0033] "Acoustic waves" are generated by one or more ultrasonic transducers. According to the present invention, acoustic waves are ultrasonic wave motions.

[0034] The acoustic waves may be generated by a single transducer or, in a variant, by at least two transducers. Each transducer may include a sonotrode, typically made of metal, which may define a surface from which the acoustic waves are emitted. The transducers may include at least one piezoelectric material.

[0035] The acoustic waves may be generated permanently as soon as the device is switched on, or as a variant may be generated only when certain operating conditions are met, for example the presence of the device in the vicinity of a hair.

[0036] The acoustic waves may be generated by a sinusoidal signal or a signal of more complex shape, for example with frequency or amplitude modulation. The acoustic waves are preferably emitted at a single frequency, which may allow them to be more precisely focused on a given area, but as a variant they may be emitted at several different frequencies. The acoustic waves may be emitted continuously or in the form of pulses.

[0037] The device may also include a system for detecting the presence of the device upon contact with hair to be treated and adjusting the function of the transducer in response to this detection.

[0038] A "probe" allows for the emission and reception of, for example, ultrasonic signals.

[0039] [Suction unit] The device according to the invention may have a suction system to collect the used cleansing composition and residues resulting from washing (natural or chemical dirt, damaged keratin residues present on the surface of the hair). The suction system may have, for example, a fan and a filter, and / or a pump and a filter, and / or a liquid collection system to collect particles, and / or an electrostatic system to attract particles to the surface by creating an electric potential field. The device according to the invention may have a reservoir of used surfactant composition, which is sucked in by the suction system.

[0040] Preferably, the output of the suction unit is set to between 80 air watts and 120 air watts.

[0041] The Air Watts standard is the ratio between air flow, suction power and electricity consumption. According to the ASTM International Standard, this standard is calculated as follows: P=1 / 8.5×F×S where P is the power output in air watts, F is the air flow rate in CFM, and S is the height of the water column.

[0042] Air Watts therefore indicates the overall performance of the suction unit's motor and therefore the effectiveness of the suction unit.

[0043] [recycling] Advantageously, the cleansing composition is delivered to contact the hair so that it can be at least partially recovered for recycling and / or filtration.

[0044] The recovered composition may be filtered to remove solid debris or its particulate phase before being re-injected into the hair tress to be cleansed.

[0045] Preferably the composition is withdrawn by aspiration or absorption, for example using a porous support.

[0046] Advantageously, the treatment and cleaning unit comprises a treatment unit inlet for receiving used composition, including composition that has been in contact with hair, and a separator.

[0047] According to a particular embodiment of the invention, the treatment and purification unit comprises a sterilization unit for killing bacteria in the recycled composition, said sterilization unit comprising a UV lamp, and / or an ozone or oxidant generator, and / or a chemical or sterilant dispenser, and / or a heating device.

[0048] Preferably, the treatment and purification unit includes a filter having a pore size of 50 microns or less. The filter may be a pleated or non-pleated non-woven fabric.

[0049] [Spray or nebulizer] The device according to the invention may be a motorized device comprising an atomizing component for misting, atomizing or nebulizing the cleansing composition. Preferably, the device according to the invention comprises a unit for treating and recycling the used cleansing composition.

[0050] In one embodiment, the nebulizer includes a compressor, a pump, and uses ultrasound to generate a mist from the cleansing composition and air.

[0051] [Preferred embodiment] Preferably, the application element according to the invention has one or more of the following features, either alone or in combination:

[0052] The opposing profile defines the boundary of the receptacle, the bottom of which defines the bearing surface, This profile promotes blocking and retention of the bundle.

[0053] The probe has an axial guide channel passing through it. Preferably, the probe has a flared hollowed-out shape. The guiding of the waves is optimized by the guide channel.

[0054] The probe has a flared shape towards its distal end, which allows easier passage of ultrasound waves and, optionally, ejection of the cleansing composition.

[0055] The bearing surface of the counter shaped portion and the distal outer surface of the probe are parallel. Preferably, the contact angle between the longitudinal axis of the probe and the hair is close to 90°. In this case, the base of the probe is advantageously flat against the hair, which provides a better treatment effect.

[0056] In one variant, the hand piece includes a first comb or a first brush positioned next to the probe and directed towards the opposing profile to untangle and aerate the hair strands before, during or after their treatment with ultrasound, thereby facilitating the passage of ultrasound between individual hairs.

[0057] In this variant, the opposing profile includes a second comb or a second brush arranged outside the bearing surface and directed towards the probe.

[0058] Thus, the opposing profile preferably comprises a groove formed in its inner contour and located between the first comb or brush and the second comb or brush in the use position of the device, said groove providing a space to facilitate the evacuation of the used composition during combing or brushing.

[0059] The ultrasonic frequency used by the transducer ranges from 16 kHz to 10 MHz, preferably from 16 kHz to 60 kHz.

[0060] The device includes a cleansing composition supply duct connected to the outlet of a reservoir containing the cleansing composition.

[0061] The device preferably comprises a spent composition exhaust duct connected to the opposing profile.

[0062] The device preferably comprises a unit for treating and recycling the used cleansing composition. The device therefore comprises a system for recovering the used cleansing composition, in particular the soiled surfactant solution. Even more preferably, this recovery device comprises a suction device.

[0063] Further features and advantages of the invention will become apparent on reading the following detailed description of a non-limiting implementation example thereof and on examining the accompanying schematic and partial drawings. [Brief description of the drawings]

[0064] [Figure 1] FIG. 2 is an oblique perspective view of a device according to the invention; [Diagram 2] FIG. 2 is an exploded view of the device of FIG. 1. [Diagram 3] 3 shows the device according to FIGS. 1 and 2 connected to a reservoir containing a cleansing composition. [Figure 4] 1 illustrates the positioning of a hair bundle in a device according to the invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0065] An embodiment of the invention is shown in Figures 1 and 2 in which the processing device includes an ultrasonic transducer 13 for emitting acoustic waves at the input of the probe. The transducer 13 is powered by a current generator 15 which may or may not form part of a handpiece 18 and is present, for example, in a base station to which the handpiece 18 is connected via a cable.

[0066] The device 1 has a facing portion 3 for receiving a hair strand that is exposed to acoustic waves emitted by a hollowed-out, flared probe 2. The probe 2 has a longitudinal axis X extending between its proximal outer surface 21 and its distal outer surface 22.

[0067] The probe 2 and opposing feature 3 are movable relative to one another between a spaced apart configuration (not shown) for introducing a hair strand therebetween, and a configuration in which they move together for processing, as shown in FIG.

[0068] The probe 2 and the counter shape 3 may be supported by an upper arm and a lower arm, respectively. The upper arm and the lower arm may, for example, be independent of each other or connected to each other at one end by a joint. The handpiece 18 thus forms a tong. The invention is not limited to a particular manner of connection of the probe 2 and the counter shape 3. However, the presence of a joint may be preferred due to the ergonomics it offers.

[0069] The probe 2 and the counter shape 3 define between them an area for the treatment of the hair, intended to receive the strand of hair to be treated, which is moved during treatment, for example in a direction from the root towards the ends of the hair, in order to ensure that the strand is thoroughly cleansed.

[0070] It can be seen from the figure that the probe 2 comprises a partially hollow elongated body including a flared flat head intended to contact or be in close proximity to a hair bundle spread out in a sheet on a bearing surface 31 formed by the bottom of the receptacle 30 such that the area of ​​the bundle to be treated is positioned facing the distal outer surface 22 of the probe 2.

[0071] The probe 2 forms a removable component associated with the counter shaped part 3, which has a cooperating shape by providing a space between the bearing surface 31 and the distal outer surface 22 constituting a recess 60 for the bundle. In the example shown, the probe 2 is moved by the user along the longitudinal axis X of the handpiece 18, away from or towards the counter shaped part 3, in order to bring the distal outer surface 22 and the bearing surface 31 into opposition to one another and at the same time to allow clamping of the bundle.

[0072] For example, grooves 39 may be located on the edge of the upper surface 36 of the counter profile 3 to facilitate drainage of used cleansing composition.

[0073] 1 and 2, the two first combs 32, 33 are arranged opposite each other on either side of the probe, and the two second combs 34, 35 are arranged opposite each other on either side of the longitudinal edge of the counter shaped portion. The two first combs 32, 33 are symmetrical to each other with respect to the mid-plane of the probe 2, and the two second combs 34, 35 are symmetrical to each other with respect to the mid-plane of the counter shaped portion 3.

[0074] Figure 3 shows a device according to figures 1 and 2 in which the cleansing composition is supplied through a supply duct 45 connected to a mixer 41 which may be connected to a water reservoir 42 and to a reservoir of concentrated cleansing solution 43, advantageously comprising at least one surfactant, preferably anionic. The cleansing composition passes through the probe through an axial guiding channel before being dispensed, for example by a sprayer or nebulizer, onto the hair after passing through the outlet orifice of the guiding channel.

[0075] The opposing profile 3 has a used cleansing composition discharge duct 44 which passes, for example, through the side wall 37 of the recess 60 for receiving the hair bundle and opens into a cup 48 for collecting the used composition.

[0076] The supply and exhaust ducts can be equipped with a motor system 40 to make the exhaust easier.

[0077] FIG. 4 shows diagrammatically a hair strand M ready to be inserted between the probe 2 and the combs 34 , 35 of the counter profile 3 when the probe 2 is brought closer to the counter profile 3 .

[0078] To use the device according to the invention, the probe 2 and the counter shape 3 are moved away from each other so that a hair bundle can be placed between them. The probe 2 and the counter shape 3 are then brought together to sandwich the bundle between the distal outer surface 22 of the probe 2 and the bearing surface 31 of the counter shape 3.

[0079] The handpiece 18 preferably has a base station 19 having a cylindrical shape. The base station 19 houses a source of electrical energy, such as one or more accumulators or cells, and a printed circuit board carrying the electronic components of the device. These components may, for example, ensure the generation of the pressure required for the atomization of the possible cleansing composition, control of the various electrical elements, and perform auxiliary functions such as calculation of the amount of product remaining to be atomized, for example to inform the user of the need to replace the cartridge containing the cleansing composition.

[0080] The user turns on the power supply and exposes the hair strand to ultrasonic vibrations for a selected period of time, particularly at least 1 second. Spraying of the cleansing composition may begin and stop simultaneously when the transducer 13 is powered on, or the start of spraying and the powering on of the transducer may be staggered in time.

[0081] The user then moves the bundle relative to the receptacle 30 so that the bundle is thoroughly cleansed over its entire length or desired length.

[0082] The cleansing composition preferably comprises one or more surfactants.Preferred surfactants are nonionic, anionic or amphoteric surfactants.Even more preferably, the cleansing composition contains at least one anionic surfactant.The anionic surfactant may be, in particular, an alkyl sulfate salt or an alkyl ether sulfate salt.

[0083] The concentration of the surfactant in the cleansing composition is preferably 0.05% by mass to 20% by mass, more preferably 0.1% by mass to 10% by mass, and even more preferably 0.2% by mass to 5% by mass, relative to the total mass of the composition.

[0084] The cleansing composition may also comprise one or more hair conditioning agents selected in particular from non-silicone cationic or amphoteric polymers, nonionic or cationic silicone oils or gums, mineral oils, oils of vegetable origin, waxes or butters of vegetable origin.

[0085] The cleansing composition may also contain other compounds selected from thickening agents, pearlescent or mattifying agents, basifying or acidifying agents, anti-UV agents, preservatives, anti-bacterial agents, anti-hair loss agents, grease control agents, fragrances.

[0086] The invention is not limited to the examples specifically described, and encompasses, inter alia, other configurations of the handpiece 18 and other aspects of the relative arrangement of the transducer 13 and the probe 2.

Claims

1. 1. A cosmetic device for cleansing hair, comprising: an ultrasonic transmitter having an ultrasonic transducer (13) powered by a current generator and configured to generate ultrasonic vibrations; a handpiece (18) including a probe (2) coupled to the ultrasonic transmitter for transmitting the ultrasonic vibrations generated by the transducer (13) to a strand of hair to be treated, the probe (2) extending along a longitudinal axis (X) between a proximal outer surface (21) and a distal outer surface (22), and the probe (2) configured such that a cleansing composition is dispensed by a sprayer or nebulizer through an axial channel passing through the probe and onto the hair; In a cosmetic device comprising: the handpiece (18) also includes a counter shaped portion (3) with a bearing surface (31) for at least partially receiving the hair strand to be treated, the probe (2) cooperating with the counter shaped portion (3) for clamping the hair strand between the bearing surface (31) of the counter shaped portion (3) and the distal outer surface (22) of the probe (2); A cosmetic device, characterized in that said counter shape (3) defines a boundary of a receptacle (30), the bottom of which defines said bearing surface (31).

2. 2. The device according to claim 1, characterized in that the probe (2) has an axial guiding channel passing through it.

3. 3. The device according to claim 1 or 2, characterized in that the probe (2) has a shape which expands in the direction of the distal end of the probe (2).

4. The device according to any one of claims 1 to 3, characterized in that the bearing surface (31) of the counter shape (3) and the distal outer surface (22) of the probe (2) are parallel.

5. The device according to any one of claims 1 to 4, characterized in that the handpiece (18) comprises a first comb or a first brush (32) arranged next to the probe (2) and directed towards the counter feature (3).

6. 6. The device according to claim 5, characterized in that the counter shape (3) comprises a second comb or a second brush (34) arranged outside the bearing surface (31) and directed towards the probe (2).

7. 7. The device according to claim 6, characterized in that the counter shape (3) comprises a groove (39) formed in the inner contour of the counter shape (3) and arranged between the first comb or first brush (32) and the second comb or second brush (34) in the use position of the device.

8. A device according to any one of the preceding claims, characterized in that the ultrasonic frequency used by the transducer (13) is in the range from 16 kHz to 10 MHz.

9. A device according to any one of the preceding claims, characterized in that it comprises a mixer (41) connected to a reservoir of concentrated cleansing solution (43) and a supply duct (45) connected to said axial channel.

10. 10. The device according to claim 9, characterized in that the concentrated cleansing solution (43) comprises at least one surfactant.

11. A device according to any one of the preceding claims, characterized in that it comprises a used cleansing composition evacuation duct (44) connected to said facing profile (3).

12. A device according to any one of the preceding claims, characterized in that it comprises a unit for treating and recycling used cleansing composition.

13. A cosmetic method for cleansing hair, comprising: (i) providing a device according to any one of claims 1 to 12, (ii) sandwiching at least one region of a bristle bundle between the bearing surface (31) of the counter feature (3) and the distal outer surface (22) of the probe (2); (iii) generating ultrasound; and (iv) where appropriate, after relative movement of the tuft of hair with respect to the probe (2), successively treating one or more other areas to clean desired portions of the tuft of hair. A cosmetic procedure that includes an operation that includes

14. 14. The method of claim 13, comprising an operation (v) comprising applying a metered amount of the cleansing composition to the hair during operation (iii).

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