Quality requirements of polypropylene masterbatch

Masterbatch quality indicators include more content. Such as the appearance of the general size of 2 ㎜ × (3 ~ 4) ㎜, pigment particle size ≤ 1 um 90% or more, melting point, DF value, MI value, heat and weather resistance characteristics. These indicators are the masterbatch plant, polypropylene fiber plant issues of common concern.

(1) Filtration performance Fiber grade masterbatch with filter performance to characterize the quality of masterbatch, its value is called DF value is small, the spinning process of the filter component replacement cycle is relatively long, generally require polypropylene masterbatch DF value Less than 2.0 × 10 Pa · cm / g.

(2) melting point of polypropylene masterbatch dispersant using low molecular weight polyethylene wax, so the melting point of 110 ~ 120 ℃; and the general melting point of the pigment is high, more than the temperature of polypropylene spinning, so masterbatch in the thermal analysis There are two endothermic peak.However, the melting point of masterbatch can not characterize the quality of masterbatch quality advantages and disadvantages, and some enterprise standards in the provisions of the melting point of 130 ~ 160 ℃.

(3) Melt Flow Index (MI) The MI of the propylene chips is mainly used to characterize the molecular weight of the chips, and to determine the processing and finished product properties after the chips are cut into fibers. The masterbatch contains pigment, dispersant and carrier low molecular weight poly Ethylene wax, it can not be used to express the level of MI molecular weight, and because of the different varieties of pigments and change, so masterbatch MI is not the masterbatch control index, only for spinning reference. Select the spinning masterbatch MI than the color slice slightly larger, beneficial to both the size of similar and mixed. General requirements for the MI value (15 ~ 30) g / 30min.

(4) heat resistance Masterbatch heat resistance index refers to the masterbatch and polypropylene slices according to a certain percentage, respectively, at different temperatures to 5 to 10 minutes cycle spinning to observe the degree of color change. Color change can be used to assess the color change with a gray-like color card or color card comparison assessment, when its total color difference ⊿ E ≤ 3, the temperature is the masterbatch heat-resistant temperature, generally require heat 270 ~ 300 ℃, color change for the four.

(5) Weatherability coloring Polypropylene weathering, with reference to textile light fastness test method, the results with the assessment of the standard blue color fastness to assess the requirements in the light fastness of 5, the fact that more than in the 6 ~ 8.