Reiner observebed the so-called Ostwald flow patterns in the system of rubber-like materials in the solvent as toluene. This flow starts as the Newtonian flow in the range of low shearing rate, and the flow pattern is followed as non-Newtonian in the medium shearing rate until realtered as the second Newtonian at the high shearing rate.
This type of flow patterns are recognized as generalized Newtonian flow in the later age. This type of flow are observed by many invesigators as Philippoff.
This type of flow, however, is scarcely observed in the gel-type material or in the suspensions of powder-like material in the fluid. Especially, the flow patterns of these suspensions free from thixotropic effects, have not been observed until the present time. In this reports, the following items have been investigated, using three type viscometers known as the rotational viscometer in the low shearing rate ranging 0.4∼80sec-1, the Kriger-Maron viscometer as the medium shearing rate ranging 30∼2000sec-1, and BS type viscometer as the high shearing rate ranging 1000∼1000000sec-1,
(1) The clay powder suspensions show the typical Ostwald pattern when the thixotropic effects are completely separated by adopting the procedure of the author's previous papers.9)10)
(2) The flow pattern of the suspensions are customarily recognized as simply pseudo-plastic or dilatant type. The Ostwald's flow pattern of these suspensions may be consistent with these traditional concept when the procedures illustrated in Figs. 7 and 8 are adopted.
(3) The silica gels showed also typical Ostwald's pattern in the 2∼8% concentration range. The dilatant flow obtained from the ZnO-water system are decided as Ostwald-like pattern as measured in the wide shearing rate range.
