The polypropylene fiber with various colors is caused by the uniform dispersion of pigment particles in the polypropylene fiber. The key is that the pigment particles are fully refined and evenly distributed (mixed) in the polypropylene fiber. Refining and dispersing is to fully refine the pigment particles and evenly distribute (mix) them in the polypropylene fiber. Refined dispersion is to break the aggregates or aggregates of the pigments to minimize the particles, and the key is to evenly disperse. The dispersion effect has an effect on the color, transparency, gloss, fiber strength, elongation and aging resistance of the colored polypropylene fiber. , The negative rate, etc. have an impact.

Generally speaking, the pigment dispersion particle size is less than 1um before it can be used for fibers or ultra-thin films, and more than 5um will cause the fiber surface to be dull, and greater than 10um will cause spots and streaks on the fiber surface, and increase with the particle size. The breaking strength and elongation of large fibers continue to decline. The finer the particle size, the stronger the coloring power and the better the dispersibility. At the same time, the smaller the particle size, the larger the surface and the increase in hiding power.

Because the pigment particle state has three types: primary particles, agglomerates, and agglomerates, and general commercial pigment particles are particles larger than agglomerates (about 75-250um), so they must be dispersed. The so-called dispersion of pigments is to reunite The process of body smashing and thinning.

In the dispersion of pigments, the first is to wet the pigment with a wetting agent and coat it on the surface of the pigment to reduce the cohesive force between the pigments and reduce the energy required to break the pigment agglomerates. The second is the pulverization and refinement of the pigment, leading the pigment particles. The free movement of the pigment (impact stress) and the pigment agglomerates break the agglomerate particles through the shear stress of the surrounding medium. After the pigment is dispersed and refined, the particle size is reduced, the surface area is increased, and the free energy of the surface of the pigment also increases, resulting in fineness. The modified pigment is not stable, so further coating treatment is required on the surface of the pigment to reduce the surface energy of the newly formed interface to prevent re-agglomeration. Then the pigment is mixed and dispersed in the melt, that is, the wetted and crushed pigment is evenly distributed. Disperse into the material to be colored.