Evaluation on Accuracy of the Rheological Data of PIM Feedstocks.

Abstract

The rheological characterization with capillary rheometer requires three major corrections named as the Rabinowitsch, Bagley and Mooney corrections. Due to the amount of time and effort needed to complete the correction procedure, some engineers may avoid the corrections. However, engineers who want to avoid it should understand how much the theological data is affected by influencing factors. In this article, the correction values made by the Rabinowitsch and Bagley corrections were analyzed for PIM feedstocks in terms of particle shape and size, powder concentration, binder composition, temperature, shear rate and capillary length. Two types of SUS powders with irregular and round particle shapes and a zirconia powder were used with wax-based binders. As results, particle shape and size were the major influencing factor followed by powder concentration. Also a longer capillary is recommended for less error as long as it does not cause thixotropic phenomenon. Without extensive experiment, a feasible result could be obtained only by the Rabinowitsch correction for feedstocks with round particle shape at a relatively low powder concentration. However, the correction is strongly recommended for feedstocks with irregular particle shape at a relatively high powder concentration.