Influence of TiO_2 attributes in highly loaded master-batch applications

摘要

TiO_2 exerts a strong influence on several key attributes critical to highly-loaded masterbatches,such as,throughput,dispersion and melt flow properties.Designing the next generation TiO_2 suitable for highly loaded(70+wt%)applications involves balancing the bulk and surface modifications to the TiO_2.This paper will present the results and conclusions from a multi-pigment study utilizing 6sigma tools for design of experiments.Grade selection for a given application is a function of the range of operating conditions,as highlighted by the studies involving 3 different TiO_2 products at 70-80 wt% loading and a wide range of fill factors using the Banbury batch internal mixer.The batch data is interpreted for its impact on a continuous mixing operation.Melt properties of the master-batch such as screen pack dispersion,melt index and capillary rheology are studied for comparing the performance of the pigments.Key attributes that help to mechanistically explain the observed behavior will be discussed.Challenges in developing the next generation of TiO_2 for the highly loaded master-batch applications will be highlighted.