ASTM D1084 Viscosity of Adhesives

Viscosity is a measure of the resistance of a fluid to deformation at a given rate. The internal friction of a liquid in motion is measured by its viscosity. The viscosity of Newtonian and near Newtonian flow characteristics can be determined using a variety of test methods. The SI unit for dynamic viscosity is pascal-second (Pa.s) or newton-second per meter square (N.s/m2).

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Scope:

The viscosity of free-flowing adhesives is determined using ASTM D1084. This test method is limited to self-leveling adhesives. ASTM D1084 excludes thixotropic and plastic materials whose viscosity is a function of stirring and adhesive history. Many industries use adhesives, including manufacturing, packaging, transportation, agricultural machinery and equipment, and the energy industry.

Test Procedure:

4 Test methods are available in ASTM D1084.

Test Method A: The adhesives are placed in the upper cylinder and the finger was used to close the cylinder’s exit. The surplus samples above the top level of the cylinder were cutted off with a straight edge. Then the samples were allowed to flow into the receiving cylinder. The material’s viscosity was measured using a stopwatch by counting the seconds from the moment the finger was removed from the orifice until the top of the meniscus reaches the 50 mL mark on the cylinder.

Test Method B: The viscosity of a single cylinder type rotational viscometer was determined by measuring the torque acting on a cylinder or disc surface spinning at a constant angular velocity in a laminar flow condition.

Test Method C: Instrument paddle has to be adjusted after conditioning the sample with standard weights of 50, 100, 200, 500, and 1000 g. Container has to be positioned on the platform and the paddle is lifted until the adhesive surface just reaches the mark on the stem.

Brake was released when the revolution counter needle crosses the zero mark. Timing device was used to record the time for 100 revs to the nearest 0.2 sec. At least three determinations were essential for ASTM D 1084.

Test Method D: After conditioning the sample hold the viscometer in a vertical position and completely immerse the cup into the sample being tested. Take the viscometer out of the sample and set it aside. Number of seconds were determined from the moment the top edge of the viscometer cup breaks the surface, the steady flow from the orifice breaks using a stopwatch. The time recording is used for estimating the material’s consistency and also to keep track of sample’s temperature and cup’s number.

Sample size:

Not specified

Data:

The data stated is regarded as standard when SI units are used, no other units are included in this standard.

Conclusion:

ASTM D1084 covers the determination of viscosity of free-flowing adhesives. This test method is limited to self-leveling adhesives.