First, MAMEO TEAM summarize the abstracts and research conclusions of six studies, then elaborate on the relationship between fabric moisture content and fabric-skin dynamic friction, as well as the correlation between fiber hydrophilicity and friction peaks, based on experimental data:
| Study Title | Abstract | Research Conclusions |
| Materials Design towards Sport Textiles with Low-Friction and Moisture-Wicking Dual Functions | Focusing on the two key comfort properties of sport textiles—moisture transfer and low friction—a double-layer nanofiber nonwoven pad was developed. The inner layer consists of polyacrylonitrile-polyvinylidene fluoride (PAN-PVDF) core-shell nanofibers, while the outer layer is a thick cellulose acetate nanofiber pad treated with a substrate. This study explores the moisture-wicking and friction-reducing effects of this double-layer structure. | The double-layer structure achieves efficient moisture wicking and low friction through a synergistic effect. The hydrophilic outer layer rapidly draws away moisture, and the hydrophobic inner layer acts as a lubricant when in contact with the skin. This “push-pull effect” prevents excessive moisture accumulation in the fabric at the skin-contact interface, thereby reducing frictional irritation. The findings provide a feasible approach for the design of sport textiles. |
| Assessing the accumulated stickiness magnitude from fabric–skin friction: effect of wetness level of various fabrics | Addressing the issue that moist skin tends to increase adhesion and friction between fabric and skin, which in turn causes discomfort or skin damage, this study uses a magnitude estimation method to evaluate fabric stickiness. Seven types of fabrics were tested at different moisture levels—achieved by drying them for varying durations on a moist “skin” surface—to simulate the state of fabrics worn after sweating. | The stickiness between fabric and skin follows a power function relationship with moisture content. Hydrophilic thick fabrics (e.g., cotton) exhibit higher saturated moisture content when in contact with moist skin, resulting in greater stickiness and higher accumulated stickiness values. Differences in fiber composition and fabric surface structure lead to variations in perceived stickiness, and stickiness is positively correlated with friction. Importantly, hydrophilic fabrics require more moisture accumulation before reaching the friction peak. |
| Human wetness perception of textile materials under dynamic skin contact | It is known that increased fabric moisture content raises friction and the perception of wetness during dynamic contact, but the impact of fabric surface texture on wetness perception remains unclear. This study selected 8 fabrics with different surface textures, divided them into groups by thickness, and had participants rate wetness and stickiness. Experimental parameters for fabric-skin contact (on the forearm) were controlled using specialized equipment. | Smoother fabric surfaces lead to a stronger perception of wetness, as they have more contact points with the skin, resulting in higher friction. Wetness perception and stickiness show a linear correlation (R²=0.64), and the predictive model becomes more accurate (R²=0.85) when thickness is included as a parameter. During dynamic contact, increased moisture content raises friction, and the surface texture of fabrics with different hydrophilicity indirectly influences the wetness feedback caused by friction. |
| AN EXPERIMENTAL STUDY OF FRICTION BETWEEN SKIN AND NONWOVEN FABRICS | Targeting the problem of dermatitis caused by friction between incontinence pads and skin, this study tested the friction between 5 types of nonwoven fabrics and skin (using the forearms of female volunteers as the test site). It explores the relationship between nonwoven properties and skin friction to provide a basis for optimizing the material design of incontinence pads. | Hydrophilic nonwovens containing viscose reach their friction peak at a moisture content of 35%-40%, while hydrophobic nonwovens containing polyester hit their friction peak at around 10% moisture content. The experiment confirms a positive correlation between fiber hydrophilicity and the moisture content at which the friction peak occurs: the more hydrophilic the nonwoven, the higher the moisture content required to reach the friction peak. |
| Interpersonal differences in the friction response of skin relate to FTIR measures for skin lipids and hydration | To investigate the causes of individual differences in skin friction response, this study uses infrared spectroscopy (FTIR) and in vivo friction testing to analyze the relationship between stratum corneum moisture, skin lipid properties, and friction coefficient. It identifies the physiological factors affecting skin friction. | Stratum corneum moisture content shows a strong correlation with friction coefficient; lipid viscosity is also correlated with friction, but lipid quantity has no impact. When using hydrophilic fabrics (e.g., cotton, viscose), fabric moisture content increases with skin perspiration, and the friction coefficient first rises and then falls. Notably, the moisture content at the friction peak is much higher than that of hydrophobic fabrics (e.g., polyester). While individual skin physiological characteristics influence friction response, the rule governing the impact of fiber hydrophilicity on friction peaks remains consistent. |
| The Influences of Hydrophilic Finishing of PET Fibers on the Properties of Hydroentangled Nonwoven Fabrics | Conventional polyester (PET) fibers are hydrophobic, making them difficult to process into hydroentangled nonwovens—and the resulting nonwovens also exhibit hydrophobicity. This study selected two types of PET fibers treated with different hydrophilic agents and untreated PET fibers to produce hydroentangled nonwovens. It examines the effects of PET fiber hydrophilicity and friction properties on nonwoven characteristics. | Hydrophilic finishing improves the hydrophilicity of PET fibers and their suitability for hydroentanglement processing. Hydrophobic untreated PET nonwovens reach their friction peak at low moisture content, while PET nonwovens with hydrophilic finishing show a significant increase in the moisture content required to reach the friction peak, along with a reduction in the overall maximum friction coefficient. Enhanced fiber hydrophilicity alters the moisture content threshold at which the friction peak occurs, thereby reducing frictional irritation. |
Relationship Between Fabric Moisture Content and Fabric-Skin Dynamic Friction
There is a “first increase, then decrease” dynamic relationship between the two, with variations in the inflection point and magnitude of change among fabrics with different hydrophilicity. For example, viscose-containing nonwovens reach their friction peak at 35%-40% moisture content, while polyester nonwovens hit their peak at around 10% moisture content. Untreated polyester nonwovens show a rapid rise in friction coefficient to the peak during the low-moisture stage, whereas hydrophilically treated polyester requires much higher moisture content to reach the peak. At low moisture levels, moisture softens the skin, increases the contact area between fabric and skin, and forms liquid bridges to enhance adhesion—all leading to a rise in friction as moisture content increases. Once moisture content exceeds the threshold corresponding to the friction peak, moisture acts like a lubricant or diffuses through the moisture-wicking function of hydrophilic fabrics, reducing frictional resistance at the contact interface and thus decreasing friction.
Correlation Between Fiber Hydrophilicity and Friction Peaks
The two exhibit a positive correlation—that is, the more hydrophilic the fiber, the higher the moisture content required to reach the friction peak, and the gentler the friction coefficient at the peak. Experimental data show that fabrics made from hydrophilic fibers such as cotton (moisture regain: 8.5%-30%) and viscose (moisture regain: 13%-40%) reach their friction peaks at much higher moisture content ranges, while fabrics made from hydrophobic fibers like polyester (moisture regain: 0.4%-20%) hit their peaks at low moisture content. For polyester fibers treated with hydrophilic agents, the moisture content at the friction peak of their nonwovens is significantly higher than that of untreated polyester nonwovens. Additionally, fabrics with a hydrophilic cellulose acetate outer layer paired with a hydrophobic inner layer can prevent a sharp surge in friction peaks through rapid moisture wicking. This is because hydrophilic fibers can store more moisture, delaying the saturation of moisture at the contact interface. Only when moisture accumulates to a relatively high level do factors (e.g., increased contact area caused by moisture) that elevate friction reach their peak—ultimately buffering frictional irritation.
