After the color formula of a white masterbatch mixing method yarn is determined, the white masterbatch is evenly dispersed in polypropylene slices before spinning, which is the key to ensure product quality. There are two specific hybrid approaches. One is the gravimetric method and the volumetric method. After the white masterbatch is melted in the middle or rear of the extruder, it is injected into the polypropylene melt with a small extruder with good uniformity
Second, in order to reduce the fiber color difference after color matching, the white masterbatch should be diluted and the mixing ratio should be controlled. Filament shall not be less than 3%~10%, and staple fiber shall not be less than 1%~3%. Monochromatic expanded continuous filaments should be spun by a three-color device. The white masterbatch must be fed into the extruder after mixing. At the same time, in order to improve the mixing capacity of the melt itself, a mixing device can be added to the extruder part.
Third, select white masterbatch according to the selection range. Polypropylene masterbatch can be divided into fine denier grade and coarse denier grade. The coarse denier white masterbatch color cannot be used for fine denier color matching. When matching colors, the number of spinning fiber monofilaments should be considered, and the same grade of white masterbatch should be selected.
The white masterbatch selected four is the product of the same manufacturer, and high-concentration white masterbatch should be selected to reduce costs. The pigments of white masterbatches can be divided into high, medium and low grades. When matching color, different grades of white masterbatches should be appropriately selected according to the quality requirements of the fiber. In order to avoid the quality change of the finished fiber due to the difference in light stability and thermal stability of the pigment, the color matching should also choose a white masterbatch color with the same light stability and heat resistance stability and meeting the fiber quality requirements. The concentration of crude fiber is lower than that of fine fiber, and the amount of white masterbatch is proportional to the square root of the denier number of fiber.
