Deciphering the Aging Mechanism of Polypropylene (PP) Nonwoven Fabric

Polypropylene (PP) nonwoven fabric is highly susceptible to aging and degradation during production, processing, and use. This is primarily due to the inherent structural characteristics of PP material and external environmental factors such as processing temperature, oxygen, light, and pollutants in the air. Visual changes mainly manifest as discoloration, powdering, and brittleness, while macroscopic performance changes are characterized by a sharp decline in tensile strength and elongation at break. The service life of the products is significantly shortened, leading to substantial material waste. Additionally, discarded products are difficult to degrade naturally and return to the environment, resulting in pollution.

The aging of PP nonwoven fabric is primarily caused by the degradation of its base resin material, polypropylene (PP). The factors contributing to this aging include: the inherent structural characteristics and residual impurities of the PP material itself; various auxiliary additives such as inorganic fillers and additives in the formulation; thermal and oxidative aging due to processing temperatures and oxygen, as well as mechanical degradation from screw shear during manufacturing; photo-oxidative aging from sunlight, particularly ultraviolet rays, in conjunction with oxygen during use; and discoloration caused by airborne pollutants under environmental conditions.