VISCOSITY, APPARENT OF PETROLEUM WAXES: ASTM D2669
EXPLANATION
This test method is applicable to fluid hot melts having apparent viscosities up to 20 Pa•s at temperatures up to 175° C.
TEST SUMMARY
Approximately 800 g of the sample is melted on a hot plate or in an oven. An 800 mL beaker, which is jacketed with an electric heating mantle, is filled with the melted sample to a level of about 1 in. from the top. The viscometer, with attached spindle and guard, is properly positioned. Stirring is begun and continued while the temperature of the sample is brought to slightly above the highest desired test temperature. Heating is discontinued but stirring is maintained until the sample cools to the chosen temperature. At this point the apparent viscosity is determined. Additional determinations are made as the sample cools. Results of temperature and apparent viscosity are plotted on a semilog paper, and values at any particular temperature are determined from the curve.
TEST PRECISION
See the precision results as follows:
High-Viscosity Sample, MI-65-20:
58 weight % of a 68° C (155° F) melting point wax.
42 weight % of an ethylene-vinyl acetate copolymer containing 27 to 29 % vinyl acetate and having a melt index of from 12 to 18.
