From the perspective of material composition, Polypropylene staple fibers possess distinct physical properties. Their specific gravity is controlled within the range of approximately 0.91. This material characteristic enables the fibers with a unit weight to have a relatively large coverage area. In terms of strength performance, the dry and wet strength indicators of Polypropylene staple fibers tend to be consistent, which is attributed to the hydrophobic nature of its polypropylene molecular structure. This structure also endows the fibers with stable resistance to acid and alkali as well as resistance to microbial erosion. Under conditions of exposure to acidic or alkaline environments or burial, the attenuation of material performance is relatively controllable. 

Due to the lack of polar groups on the molecular chains of polypropylene, the dyeing process of polypropylene short fibers is usually completed before the spinning stage, that is, the fibers are colored using the color masterbatch coloring method. At the same time, its moisture regain value is relatively low, which also constitutes a consideration factor in the later processing of the fabric. 

Diversified application fields

The application fields of Polypropylene staple fibers exhibit a diversified distribution. In the geotechnical engineering field, it is processed into geotextiles or mixed into the concrete matrix. When used as a concrete reinforcement material, the uniformly dispersed polypropylene short fibers can inhibit the formation of cracks during the plastic stage and enhance the impact resistance of the structure. In transportation infrastructure projects, the woven geotextiles made of polypropylene short fibers can be involved in the reinforcement of soft soil foundations and assist in stress dispersion. 

The non-woven fabric industry is a major consumer of Polypropylene staple fibers. Through processes such as hot rolling or needle punching, it can be transformed into the covering layer for disposable hygiene materials, the base material for filtration materials, and the sound insulation felt for automotive interiors. In the field of hygiene materials, the finer polypropylene short fibers utilize the capillary effect, which helps maintain the dryness of the contact surface. In the field of home decoration, the felt or carpets filled with polypropylene short fibers are favored for their anti-termite and easy-cleaning properties. 

Regular product categories and production processes

The linear density of regular polypropylene staple fibers ranges from 1.5 dtex to 15 dtex. The cutting length is adjusted according to the end use. For example, the length of fibers used for concrete reinforcement is usually between 15mm and 20mm, while the length for spinning purposes is adapted to the regular cotton-type specifications of 38mm to 51mm. For specific scenarios, the industry has also developed modified short fibers such as UV-resistant, flame-retardant, and antibacterial types to meet the requirements of outdoor products or the medical field. 

The production process of polypropylene short fibers involves steps such as raw material blending, melt extrusion, stretching and setting, and cutting and packaging. The setting of the stretching ratio is directly related to the linear density and strength indicators of the fibers. In the post-processing stage, the curling process gives the fibers the necessary cohesion, facilitating the subsequent process of carding and forming a net. 

Currently, with the changes in demand in the infrastructure maintenance and hygiene products markets, the polypropylene staple fiber industry is adjusting towards a direction of functionality and differentiation.