A New Material for Skin Concerns: What Is "Moist Fiber," Developed by Momotani Juntenkan Ltd. with 130 Years of Technology?

Have you ever felt itching or discomfort when clothing touches your skin? In recent years, there has been a noticeable increase in people suffering from atopic dermatitis and allergies, especially in developed countries.

Rising to meet these skin concerns is the pioneering cosmetic maker, "moist fiber," which developed the world's first fiber. I spoke with Teizo Sugino, the director of the Next Research & Innovation Lab at Momotani, about the potential of this new fiber and the story behind its development.

Founded in 1885 (Meiji 18), Momotani Juntenkan Ltd. started with the creation of "acne-removing beauty water" by its founder to address his wife's skin concerns. Upholding the founding spirit of "wanting to be of service to as many people as possible," the company has continued to launch numerous products to this day.

Many may be familiar with their products like "Moist Labo" and "MEDI SHOT." However, why did a cosmetics company decide to develop a fiber like Moist Fiber?

“The development of Moist Fiber began with the recognition of the increase in atopic dermatitis. Many people suffering from atopic dermatitis and allergies can be found in developed countries, and it is believed this will continue to increase with global development. However, many aspects of atopic dermatitis and allergies remain scientifically unexplained.

"We are conducting daily research with the intention of using our extensive knowledge from years of cosmetic development and scientific evidence uncovered in our research institute to assist people troubled by atopic dermatitis and allergies.”

Even for those without atopic dermatitis, conditions like eczema and itching can occur. Numerous functional fibers have been developed, and some may cause irritation or discomfort for those with sensitive or dry skin.

“Clothing is often referred to as a second skin and serves as a significant barrier between the skin and the external environment. Therefore, we aimed to develop a material that allows individuals with sensitive skin to enjoy fashion freely by utilizing our cosmetic development expertise in fiber development.”

For over 130 years, Momotani Juntenkan has been researching skin flora and sterilization technology. One outcome of this is the world’s first antibacterial ingredient "Floracontroller FC161."

Moist Fiber is a new material that incorporates this FC161 into the fiber, in collaboration with the fiber company, Omikenshi Co. Ltd.

“In the past, it was believed that bacteria should be eliminated for beautiful skin; however, recent views recognize that beneficial bacteria also exist for the skin. Understanding skin condition requires not only information such as moisture and oil levels, but also the balance of skin flora.”

According to Sugino, Staphylococcus aureus is a harmful bacterium that releases toxins that damage the skin's barrier function.

“Moist Fiber, which contains FC161 that suppresses only harmful bacteria, provides moisture to the skin when in direct contact and helps regulate skin flora. It is developed as a 'wearable cosmetic' that allows skincare simply by wearing it.”

Momotani Juntenkan's Moist Fiber is patented as it incorporates FC161 into the fiber using a special technique. There is a significant difference in processing methods and efficacy verification compared to typical moisturizing products on the market.

“There are many fiber products that claim moisturizing functions, but most of these express the fiber's own moisture-absorbing capabilities, which differ from moisturizing effects on the skin. Additionally, there are two methods for imparting moisturizing ingredients onto fibers: the blending method during fiber formation and the post-processing method applied after the fibers are created.”

Generally, post-processed items tend to lose effectiveness during washing, but the blending method adheres strongly to the fiber, making it resistant to washing. Rayons derived from pulp were chosen as the material.

“Rayon is easy to blend with components and excels in moisture retention, providing a pleasant wearing experience, making it applicable to various fiber products. However, Rayon alone tends to be fragile, so we are referencing insights from fiber companies and clients during product development.”

The processing of Moist Fiber utilizes technology from cleansing oils.

"To be effective, it is necessary to incorporate a sufficient amount of ingredients. Therefore, we applied our cleansing oil formulation technology. Since cleansing oils contain very little moisture, they are suitable for incorporating a large amount of oil-soluble active ingredients. Moreover, when added to the water tank during fiber manufacturing, it can micro-emulsify the active ingredients, allowing for efficient absorption into the fibers."

Thorough verification of effectiveness was also conducted.

"We measured the skin moisture level after 4 hours of wearing and assessed skin barrier function and flexibility after 8 hours to confirm the effectiveness. In the apparel industry, the focus is often limited to texture, but we aim to validate effects from multiple angles, similar to cosmetics, to help those with skin concerns."

In the effort to commercialize Moist Fiber, many challenges were encountered.

"The variety of fibers and materials presented a difficult point. In the research, the effectiveness was confirmed with fabrics containing 30% Moist Fiber, but in actual product development, there were cases where the effectiveness could not be verified."

Upon investigation, it was discovered that the pH level of the fibers posed a problem. One fiber was skewed toward alkalinity, affecting efficacy. Additionally, the processing agents used in the dyeing process had such strong antibacterial properties that they killed beneficial skin bacteria.

"Even the sewing process caused differences in effectiveness, so we made adjustments, such as using Moist Fiber for the threads that touch the skin. We started from a situation where there was almost no process to turn apparel products into cosmetics, facing numerous challenges."

The path to commercialization was long, requiring 2 to 3 months for the creation of a single sample.

"It took more time than typical cosmetic development, which was frustrating, but collaboration with the textile industry led to new insights, resulting in the world’s first Moist Fiber fabric."

Momotani Juntenkan will showcase Moist Fiber at the upcoming Osaka Expo. In the "Sustainable Future Co-Creation Project" within the "Kira Kira Zone," they plan to propose a vision of "a comfortable and exciting future without skin troubles."

"Many apparel manufacturers are participating in this project, and Momotani Juntenkan is the only cosmetics manufacturer involved. While utilizing Moist Fiber, we want to convey messages about the future and the environment, such as 'clothes that photosynthesize' and 'transparent-looking clothes.'"

They are also planning exhibitions that utilize scents and interactive experiences where visitors can learn about skin resident bacteria through games. "Through Life Science x Technology, we hope that many people will feel a 'future without skin troubles,'" said Sugino.

The global market for atopic dermatitis is expected to reach a value of 21.4 billion US dollars by 2030［1］. Moist Fiber has the potential to be a salvation for many people with skin concerns, as well as to invigorate the cosmetics and apparel industries.