Since hair cosmetics are so important in our daily life, EnterCo here introduces the hair efficacy evaluation in our own Innoderm Laboratory for you.
How is the hair damaged?
Arrangement and combination of hair problems with triple structure of hair
The hair shaft can be divided into three parts: hair scales, hair cortex, and hair medulla. Hair cortex stores moisture, protein, and pigments that determine the color of hair, such as eumelanin and pheomelanin.
In daily life, hair will inevitably be damaged by external factors, which will lead to changes in physical and chemical properties. From a microscopic point of view, if the hair scales are damaged; the moisture of the hair cortex is reduced; and the keratin is denatured, the hair will become dry, and easy to break with split ends. Excessive perm and dyeing will lead to the reduction of the less stable eumelanin in the hair, which will appear yellow.
Damaged hair under micro-structure
After understanding the structure of hair and the micro causes of hair damage, how can we judge whether the efficacy of hair cosmetics is effective?
What are the evaluation methods of hair efficacy?
For the evaluation of hair efficacy, the instrument method or sensory test method is generally used. (Note: this article mainly introduces the method based on the fibra.one—hair multi-function test system)
1. Hair softness, smoothness, and combing test
For hair products, improving the hair's softness and smoothness is one of the very important indicators. The main factors determining the hair's softness and smoothness are the friction on the hair surface and the stiffness of the hair itself.
■ The smaller the friction resistance coefficient is, the smaller the hair stiffness is, indicating that the hair is smoother;
■ The smaller the combing force is, the better the hair combability is, indicating the effect of hair care products is better.
The hair multi-function test system fibra.one can be used to conduct the combing test, friction performance test, and three-point bending resistance test.
2. Hair tensile strength test
Under normal circumstances, the strength of hair is closely related to the degree of damage caused by perming and dyeing and the use of hair care products. The commonly used method in the industry is to conduct a single hair tensile strength test (stress) through the fibra.one (hair multi-functional testing system) to verify hair care results.
A single strand of normal hair was randomly selected, and the tensile properties were tested, and the changes in the maximum breaking force before and after using the hair product were compared.
■ The bigger the maximum breaking force is, the stronger the hair stretch is, indicating the effect of hair products is better.
3. Hair gloss test
Hair gloss is an important reflection of the sensory judgement of hair texture. The hair scales of healthy hair are arranged regularly, and the light will be reflected evenly on the surface of the hair scales. According to this principle, we can use the skin gloss test probe GL200+ hair module to measure the hair gloss.
4. Hair moisture test
As mentioned above, the hair cortex stores moisture and proteins. The higher the damage to the hair, the easier the moisture in the hair will be lost. Therefore, the mass method can be used to measure the change in hair quality before and after the moisture evaporates.
Data of hair moisture measured by mass method
Data source: Innoderm laboratory
5. Sensory test method
In addition to relying on different instruments to measure various data above, the sensory test method can also be used to evaluate whether hair products are effective. It is generally evaluated by several trained and experienced professionals through scoring standards formulated by different laboratories. The main dimensions include: the combability of dry and wet hair, the feel of dry and wet hair, gloss of hair observed with the naked eye, etc.
As people pay more and more attention to hair care, the categories of hair products will become more and more refined, and the evaluation method of the actual efficacy of products will become more important.
If you have any questions related to the hair efficacy evaluation test, please get in touch with us via email@example.com.