VISCOSITY, APPARENT OF HOT MELT ADHESIVES: D3236
EXPLANATION
This test method covers the determination of the apparent viscosity of hot melt adhesives and coating materials compounded with additives and having apparent viscosities up to 200 000 mPa. s at temperatures up to 175° C. It is believed that apparent viscosity determined by this test method is related to flow performance in application machinery operating under conditions of low shear rate. The results of this test may not correlate well with end use applications where high shear rates are encountered. This test method may be adaptable to viscosities higher than the present 200 000 mPa. s limit and temperatures above 175° C. However, precision of this case has not been studied.
TEST SUMMARY
A sample of molten material is maintained in a thermally controlled sample chamber. Apparent viscosity is determined under temperature equilibrium conditions using a precision rotating spindle type viscometer. Data obtained at several temperatures can be plotted on appropriate semi-log graph paper and apparent viscosity at intermediate temperatures can be estimated.
TEST PRECISION
Repeatability: 8.8 % of the mean
Reproducibility: 25.4 % of the mean
There is no bias.
