How to adjust the surface friction coefficient of nonwoven fabrics?

2025-12-03 14:35:11

The adjustment of the surface friction coefficient of nonwoven fabrics is mainly achieved through three dimensions: fiber surface treatment, structural design, and functional additives. Fiber surface treatment is a direct method. Plasma treatment can introduce polar groups or micro/nano-scale rough structures onto the fiber surface, thereby altering the interaction forces at the contact surface. Low-temperature plasma treatment, while maintaining the fiber's intrinsic properties, adjusts the friction coefficient by changing the surface chemical composition. Physical vapor deposition (PVD) technology can construct low-friction coatings such as diamond-like carbon films on the fiber surface, significantly reducing sliding resistance. Chemical grafting modification fixes silanes or fluorocarbon compounds onto the fiber surface through covalent bonding, forming a stable low-friction interface.

Structural design provides a more macroscopic control of the friction coefficient. By changing the fiber arrangement density and orientation, anisotropic frictional characteristics can be created, with friction differences between the machine direction and the transverse direction reaching over 30%. The construction of three-dimensional structures, such as surface embossing or textured designs, can reduce the actual contact area, thereby lowering the apparent friction coefficient. In multilayer composite structures, the combination of surface layers with different frictional properties with the substrate can achieve gradient changes in frictional performance. The choice of fiber diameter and length also affects frictional behavior; short, fine-denier fibers more easily form smooth surfaces, while long, coarse-denier fibers generate higher frictional resistance.

The use of functional additives provides flexible adjustment methods. Solid lubricants such as graphite and molybdenum disulfide powders, added to the fiber web at a ratio of 1-3%, can form a transfer film at the friction interface; silicone oil or fluorine-based finishing agents form a molecular-level lubricating layer on the fiber surface through impregnation treatment; the introduction of nanoparticles (such as SiO2 or TiO2) modulates frictional properties by changing the surface morphology. The selection of these additives must consider compatibility and durability with the substrate to avoid migration or shedding during use.

Post-processing plays a crucial role in shaping the coefficient of friction. The combination of hot rolling temperature and pressure affects surface smoothness; high temperature and light pressure produce a glossy surface and reduce friction, while low temperature and high pressure retain more fiber hairs and increase friction. The water pressure and nozzle arrangement in the hydroentangling process determine the degree of fiber entanglement, thus affecting surface bulkiness. The type and distribution of chemical adhesives also change interfacial properties; polyurethane adhesives generally provide a lower dynamic coefficient of friction than acrylic adhesives. The combined use of these adjustment methods allows the surface friction coefficient of nonwoven fabrics to be precisely controlled within a wide range of 0.15-0.8.