The masterbatch industry has also been greatly developed along with the development of related industries. The production level of masterbatch technology has also made unprecedented progress, and the application field of masterbatch has also been continuously expanded. However, due to the influence of the traditional Chinese market competition model, it is always the pursuit of "low quality, low price, and usability", which results in the production of downstream masterbatch application enterprises is not stable enough, the quality is low, and the product is not competitive. Many masterbatch application manufacturers have been widely recognized, especially polypropylene manufacturers with high quality requirements pay more attention to the impact of masterbatch quality on polypropylene quality. For this reason, according to the requirements of the Polypropylene Chemical Fiber Industry Association, the effect of color masterbatches on the quality of polypropylene
First, the dispersion of masterbatch in polypropylene fiber
Polypropylene fibers with various colors are caused by the uniform dispersion of pigment particles in the polypropylene fibers. The key is that the pigment particles are fully refined and evenly distributed (mixed) in the polypropylene fibers. Refining and dispersing means that pigment particles are sufficiently refined and uniformly distributed (mixed) in polypropylene fibers. Refining and dispersing is to break up the aggregates or rounds of the pigment to minimize the particles, and the key is to uniformly disperse. The effect of dispersion on the brilliance, transparency, gloss, fiber strength, elongation, and aging resistance of colored polypropylene fibers , Electricity negative rate and so on.
Generally speaking, pigments with a particle size of less than 1um can be used for fibers or ultra-thin films, and more than 5um will cause fiber surface? ** Fumigation? More than 10um will cause spots and streaks on the surface of the fiber. As the diameter increases, the breaking strength and elongation of the fiber continue to decrease. 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 higher the hiding power.
Since the pigment particles have three types: primary particles, aggregates, and reunions, the general commercial pigment particles are larger than the reunions (about 75-250um), so it must be dispersed. The so-called pigment dispersion means reunion. The process of body pulverization and refinement.
The dispersion of pigments is firstly wetting the pigment with a wetting agent and coating it on the surface of the pigment to reduce the cohesion between the pigments and reduce the energy required to break up the pigment mass. Secondly, the pigment is pulverized and refined, leading among the pigment particles. The free motion (impact stress) and the pigment round body break the round body particles by 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 pigment surface is increased, which results in the instability of the refined pigment. Therefore, the pigment surface needs further coating treatment to reduce the newly formed interface surface. It can prevent re-aggregation, and then the pigment is mixed and dispersed in the melt, that is, the pigment that is wet and pulverized is evenly distributed to the material that needs to be colored.