The object of the present invention is a method for hair straightening through exposure to a modified atmosphere and to a variation in temperature, as well as a relative straightening device.
As is known in the field of hair treatments, and in particular the straightening of curly or frizzy hair, the changes on the hair are made through mechanical, thermal and chemical actions.
At present, the most common straightening method by thermal/mechanical action involves heating the hair during combing, in order to make it smooth, usually with a hair dryer and a brush or with a hair plate. As is known, this method has only a temporary effect, lasting from a few hours to a few days, and with a significant deterioration of the hold if the hair is exposed to moisture or other external factors.
In order to counteract these negative effects, therefore, chemical products are often used which allow an extension of the duration and the hold of the straightening. This known method, however, exposes the subject treated to unpleasant vapors, long treatments, and not always positive results, as well as a weakening of the hair due to the aggressiveness of the chemical reagents used.
The known methods (see for example
The object of the present invention is to solve the problems of the prior art taking into account the needs of the field.
In particular, the object of the present invention is to provide hair straightening by means of a method which does not involve the use of aggressive or damaging chemical compounds for the hair, and ensures a lasting straightening without causing excessive stress on the hair.
This object is achieved by a straightening method according to claim 1, as well as by a straightening device according to claim 10. The dependent claims describe preferred embodiments of the invention.
Further features and advantages of the straightening method and of the respective device will be apparent from the detailed description that follows, illustrated by way of non-limiting example in the accompanying figures in which:
The method according to the present invention provides for subjecting the hair to a thermal and mechanical action, by means of a straightening plate, simultaneously with exposure to an atmosphere enriched with hydrogen gas.
The straightening method provides for:
In particular, the plate is heated to a working temperature T of between 200 °C and 250 °C, preferably to 230 °C.
The gas environment around the hair during the passage of the plate is composed of air in which:
In an embodiment example, the method involves applying a pure hydrogen gas flow to the hair through nozzles distributed along the plate or in its vicinity, allowing at its dispersion the proper dilution, and at the same time passing the plate slowly over one lock at a time. The hydrogen flow is supplied with a flow rate between 150 ml/min and 250 ml/min, preferably 200 ml/min.
Preferably, the method involves passing the plate slowly over a lock at a time carrying out at least a total of ten passages on the same lock. The passages can be consecutive, or interspersed with an intermediate treatment step.
The method may also include a pre-treatment step in which the hair is moistened with an aqueous solution. For example, the pre-treatment step involves moistening the hair with water, spraying a total of 1.2 ml.
In a further example, the hair is moistened with demineralized water.
In a further example, the hair is moistened with saline water containing 3% sodium chloride.
In a further example, particularly suitable in the case of bleached hair, the aqueous solution comprises 0.1% polyglutamic acid. This solution allows improving the structure and the shine of the hair.
In a further embodiment, the method can also provide a pre-treatment step in which the hair is combed with a brush (set treatment).
In a further embodiment, the method can also provide a pre-treatment step in which the hair is washed with shampoo and dried with a hair dryer.
The method can also provide an intermediate treatment step, provided between the straightening passages, in which the hair is moistened with an aqueous solution. It is important that this step does not leave residues of runny water.
The method also includes a post-treatment step, in which the hair is washed with shampoo, even more than once.
The locks are classified according to the type: African; Very frizzy; Soft curly; Frizzy curly; Frizzy and wavy.
Both natural locks and bleached locks are selected.
A standard treatment protocol is defined in which the hair is moistened (sprayed with water for a total of 1.2 ml), the plate is heated to a temperature of 230 °C, and the hydrogen flow is made to escape from the center of the plate (flow rate of 200 ml/min).
The steps of the method followed in the various tests are defined below:
The results of the tests carried out were evaluated considering the straightening degree obtained, gloss and tactile consistency. The evaluation was then summarized in: negative result; sufficient result; good result. This evaluation (summarized in
As can be seen from the result of test 7P, a plate temperature of 160° is considered insufficient to obtain a sufficient result; the plate must therefore have a temperature of at least 200 °C, preferably of 230 °C.
Furthermore, as can be seen in the result of test 3P (performed as a reference sample for sufficiency, by a known chemical straightening treatment), the tests relating to the method according to the present invention all lead to a better straightening result, with the sole exception of test 4P performed on bleached hair.
With reference to
The device 1 comprises a gas flow generator 10 connected, through a conduit 14, to a dispensing plate 20 heated to a working temperature T.
The gas flow generator 10 comprises a hydrogen generator 11.
In an embodiment example, the hydrogen generator 11 is a hydrolyser. The electrochemical method for hydrogen production uses electrolysis which separates hydrogen and oxygen from water. The electricity applied in the system breaks the chemical bonds between the two atoms that make up a water molecule; the two gases that form hydrogen and oxygen migrate, the first one towards a cathode and the second one towards an anode.
In a further embodiment example, the hydrogen generator 11 is a proton exchange membrane (PEM). It is a hydrolysis cell with a polymer membrane, in which the production of hydrogen takes place simply using only distilled water without using corrosive solution.
In a further embodiment example, the hydrogen generator 11 is at least one hydride cylinder. In particular, in the medium-low pressure anhydrous hydrogen cylinder, the gas is present in a compound based on metal hydrides (canister) previously loaded by a suitable device. These cylinders have the advantage of storing hydrogen at low pressure and can be refilled. The advantage of this implementation is the total safety and independence from corrosive liquids and compounds in free gaseous form.
The gas flow generator 10 further comprises, connected to the hydrogen generator 11, an enrichment device 12 for enriching the gas flow with vapor from liquid, e.g. steam.
In an embodiment example, the enricher 12 is a bubbler.
In a further embodiment, the enricher 12 is an ultrasonic wet mist generator in the presence or absence of heating of the mixture.
The gas flow generator 10 further comprises pumping means 13 adapted to push the gas flow, through the conduit 14, towards the dispensing plate 20.
The gas flow generator 10 further comprises means for regulating the gas flow (not shown).
The dispensing plate 20 (shown in detail in
The dispensing plate 20 comprises a front straightening portion 22, which houses a pair of heating elements 21, and a rear handle portion 23 which allows an easy manual use of the dispensing plate 20.
In particular, the front straightening portion 22 further comprises dispensing means 24 for the gas flow, connected to the conduit 14. The dispensing means 24 are adapted to dispense the gas flow precisely at the heating elements, to allow the correct execution of the method according to the present invention, which provides for applying a gas flow to the hair while simultaneously passing the plate (straightening) on the locks.
Innovatively, the straightening method according to the present invention allows obtaining excellent levels of hair straightening without the use of aggressive chemical compounds or harmful for the hair.
Advantageously, the straightening method according to the present invention ensures a lasting straightening without causing excessive stress on the hair.
It is clear that a man skilled in the art can make changes and variations to the straightening method and to the relative device described above, all falling within the scope of protection as defined in the following claims.
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.