Polypropylene monofilament fiber is a kind of synthetic polypropylene fiber, also know PP microfiber .The diameter of monofilament is between 15-60 microns. The common specifications are 18 microns and 34 microns. It is made of polypropylene of equal specification by direct drawing through several spinneret holes after melting. The fiber section can be circular or special-shaped, and several monofilaments become fiber bundles after stretching, qualitative and short cutting to a certain length. After mixing with concrete, the fiber bundle will be evenly dispersed in the concrete after mixing by mixer, and form an irregular and multi-phase three-dimensional support system.
Polypropylene monofilament fiber is mainly used in the field of mortar and concrete, as well as gypsum, papermaking and other products. In mortar or concrete, it is used to restrain the plastic shrinkage cracks of cement mortar and concrete before curing and increase the toughness of cement mortar and concrete, so as to improve the internal quality of cement mortar and concrete, reduce maintenance cost and prolong the service life of the project.
Main functions of polypropylene monofilament fiber in concrete:
1. Reduce and restrain the plastic shrinkage cracks of concrete and improve the durability of concrete. Polypropylene monofilament fiber can reduce and inhibit the formation of plastic shrinkage cracks in concrete, improve the impermeability and frost resistance of concrete, and improve the durability of concrete.
2. Prevent the segregation of concrete and improve the homogeneity of concrete. The existence of polypropylene monofilament fiber prevents this segregation phenomenon and thus prevents the formation of plastic settlement cracks.
3. Reduce and prevent early temperature shrinkage cracks of mass concrete. Polypropylene monofilament fiber can withstand the tensile stress caused by temperature difference, so as to reduce or prevent the formation of early cracks.
4. The melting point of polypropylene monofilament fiber is between 160-173 degrees. Therefore, when the concrete encounters a fire, after the fiber melts, a porous state will be formed in the concrete, which can effectively release the internal pressure caused by temperature change and improve the fire resistance of the concrete.
