Flow Properties of Lubricants Under High Pressure

In this paper, results are given of a preliminary study of the rate-of-shear versus shear-stress relationship for several oils known to undergo apparent solidification when subjected to high pressure. Lard, rapeseed, sperm, and one mineral oil were tested under a temperature range of −5 C to 20 C while subjected to pressures up to 50,000 psi. Experimental curves of flow versus pressure difference were obtained for capillary flow, and these curves were transformed mathematically to the desired curves of rate of shear versus shear stress. A brief discussion of some of the problems inherent in capillary testing of plastic materials is included in this report.