What a Curl Needs
Curl control, moisturization, prevention of hair breakage and frizz are the primary issues to address when formulating products specifically for textured hair. Tightly coiled hair has elliptical cross-section diameters changing along the hair fiber length as it twists.
The number of cuticle layers along the hair shaft also varies, with weak spots created at the point of curvature where there are fewer layers. The cuticle consists of a number of tightly overlapping layers coated with 18-MEA, a hydrophobic lipid which minimizes the amount of water going in and out of the underlying cortex and plays an important role in protecting hair. Raised cuticles and loss of the lipid covering results in negatively charged “weathered” hair, characterized by tangling, frizz, breakage and loss of curl structure.
Curl geometry means that the helical configuration creates areas where the overlapping cuticle layers are unable to close, making textured hair more porous and vulnerable. Textured hair is also prone to dryness as natural lubricating oils produced by sebaceous glands in the scalp can’t “slide” down the shaft to reach the ends because of the bends and kinks.
Conditioning product efficacy is determined by the formula’s ability to neutralize the negative charge of damaged hair, as well as reduce static, and smooth and flatten the cuticle. Primary conditioning agents are positively-charged molecules and include cationic surfactants, polymers and amino functional silicones.
The negative charge of the hair is attracted to the positively-charged molecules resulting in good deposition on the strands, particularly on the more negatively-charged damaged areas. Secondary conditioning agents include emollients and oils, occlusive agents and humectants to lubricate and reduce friction between hair fibers to give a smooth feel and improve combability.
Shea offers an excellent sustainable, biodegradable alternative to synthetic ingredients as secondary conditioners in hair care products. Shea butter has long been used as a natural hair emollient by women in rural African communities. Shea butter is massaged into the scalp or used to coat hair strands to help seal in moisture and protect against the hot, dry climate. Consumers seeking products for textured hair rank ingredients as the top purchasing consideration with 54% citing shea as the most desirable, according to Phoenix Marketing International.
Lipex SheaLiquid TR (INCI EU: Butyrospermum parkii butter (or) Butyrospermum parkii oil) offers a functional alternative to other widely used benchmark plant oils for conditioners, such as argan oil or solid shea butters. A versatile, easy-to-use fluid, shea oil contains a high content of triterpene esters and contributes excellent anti-frizz properties, moisturization and glide. It gives rich emolliency and can be used in higher concentrations without increasing viscosity, making it ideal for providing body and texture to conditioning treatments and curl defining styling formulations. It also benefits from a fully traceable supply chain, originating from the Kolo Nafaso direct sourcing program run by AAK in Burkina Faso.
Wet Comb Force Reduction
In a recent independent study, Lipex SheaLight (INCI EU: Shea butter ethyl esters) and Lipex L’sens (INCI EU: Soybean glycerides (and) butyrospermum parkii butter unsaponifiables), alone and in combination, were shown to outperform both synthetic and placebo benchmarks in reducing wet combing force reduction, making them an excellent choice for formulating rinse-off conditioners for textured hair.
In addition to excellent wet combing force reduction, Lipex L’sens provides body to both hair and formulation. A highly polar, semi-solid emollient, it offers lanolin-like properties with respect to touch, structure, gloss, film-building and water-absorbing capacities, which can be of particular benefit when formulating specialized styling and treatment products for textured hair. In contrast, Lipex SheaLight is suitable for cold processing, sprayable and clear styling formulations, providing a low viscosity, lightweight alternative to non-volatile silicone oils, mineral oils and synthetic esters.
The hydrophobic properties of triglyceride oils make them particularly useful as conditioning and protecting agents in hair care formulations, as they can improve combability, enhance sensory properties and add shine. For optimal results, it is often advantageous to use a combination of ingredients. For example, a low-viscous, high-spreading shea butter ester helps distribute conditioning oils over the hair surface while a more polar ingredient, such as Lipex L’sens, will improve wet combing properties and give the necessary adhesion to the hair strands to combat frizz.
When selecting ingredients, stability and composition will always be the most important factors for consideration, but increasingly, sustainability and environmental properties are playing a role in driving choice, resulting in the rise in the number of tropical oils being used. However, for functionality, stability, mildness and sustainable credentials, shea butter and shea oils remain excellent options and should always be considered.
AAK Personal Care
Jari Alander is currently the director of customer innovation at AAK Personal Care, managing AAK’s technical customer interactions within personal care applications. He’s a physical chemist by training, specializing in lipid chemistry and applications since 1985.
After having worked with food applications, including dairy, chocolate and nutritional products, Jari has devoted his time to personal care applications since 2003, working in new product development, claims substantiation and application of AAK’s emollient technologies.
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