Polypropylene fibers mainly include short filaments, filaments, spunbonded non-woven fabrics and melt-blown non-woven fabrics. To prepare a masterbatch for polypropylene spinning, you also need to pay attention to many details, and the masterbatch used is not only In line with the excellent heat resistance and excellent dispersion and migration resistance of chemical fiber spinning, it is also necessary to meet the light resistance and weather resistance in chemical fiber applications.

Heat resistance

Because the spinning process of polypropylene fiber is different, its spinning temperature is 230~300℃, therefore, the selected pigment must have excellent heat resistance. Classic Pigment Red 48:2 is widely used in polypropylene carpet yarn. It is necessary to pay attention to the phenomenon that it will lose crystal water when spinning at high temperature and will absorb water and change color repeatedly when stored.

  In addition, copper and other metal ions can accelerate the oxidative decomposition of polypropylene resin, so the content of these metal ions must be strictly controlled. For example, copper phthalocyanine pigment, which uses cuprous chloride as one of the main raw materials, is used in C The control of copper ions in spinning is a very important indicator, and it must be refined if necessary to remove excess free copper ions.

Dispersion

When the masterbatch is used for the dispersion of polypropylene, consideration should be given to: breakage of the spinneret, tensile deformation, tensile breakage, replacement frequency and service life of filter components. Especially ultra-fine denier polypropylene is a new variety that is developing towards the thinning of artificial silk and fabrics. It has higher requirements for pigment dispersion. The polypropylene masterbatch uses the filtration pressure rise to characterize the dispersion quality of the masterbatch, and its value is called DF Generally, the DF value of polypropylene masterbatch is required to be less than 1.0.

  The dispersion of the pigment can be achieved by adding polyethylene wax, EBS and other dispersants. According to the type and performance of various dispersants, the amount of addition can be determined according to the required dispersion effect, but the principle of as little as possible must be observed, because too Too much dispersant will cause the melt viscosity to drop during spinning, and it is easy to float and break.

Weather resistance

Polypropylene fiber is the lightest fiber among common chemical fibers. It hardly absorbs moisture, has high strength, and the fabric made of it has stable dimensions, abrasion resistance, good elasticity, and good chemical stability. Therefore, it is widely used on sunshade cloth, so it needs good When choosing pigments with good weather resistance, pay attention to choosing pigments with large particle sizes and adding appropriate anti-oxidation, anti-ultraviolet and other anti-aging additives.

Melt Index

The masterbatch for polypropylene filament requires a melt index of 15-50g/10min, the masterbatch for spunbond non-woven fabric requires a melt index of 40-60g/10min, and the melt-blown non-woven fabric masterbatch requires a melt index of 800- 1500g/10min.4.5~5.0g/1min. Therefore, when choosing a masterbatch, pay attention to whether its melt index can reach the melt index required by polypropylene filament.

Water content

If the spinning speed of polypropylene filament is 600-800m/min, the moisture requirement of polypropylene resin and masterbatch is not high. Like the one-step method, the spinning speed is as high as 2000-3000m/min, or even faster. Slightly high water content of color masterbatch often causes abnormal spinning. Generally speaking, the water content of the masterbatch is required to be controlled at about 500mg/kg.

safety

As people's awareness of environmental protection continues to increase, polypropylene masterbatches are required to not contain a variety of restricted heavy metal factors, and various pigments containing lead and cadmium must not be used, which meets the requirements of ecological textiles.