The Stein Hall Viscosity Cup is used in viscosity testing where the number of seconds required for a set volume of adhesive to flow through the viscometer’s orifice. Viscosity is an important property of starch based adhesives and strongly affects bonding at the corrugator. Some pastes are too thick for certain paper and some are too thin, this is where viscosity testing is important. The apparent viscosity of adhesives used in the manufacture of corrugated containerboard is measured by the number of seconds required for 100 cc of adhesive to pass through an orifice in a disc. The instrument used throughout the industry since 1934 is called a Viscosity Cup or Stein-Hall Cup. The readings obtained do not directly correspond with any other viscosity scale.

The cup must be calibrated before performing the test. Check the orifice to make sure it is not plugged, corroded or worn. Manufacturing variations in orifice size and tube diameter make it necessary to calibrate each cup to a known standard. In addition, calibration may be required due to a worn disc or when replacing the disc.
 

Calibration Procedure: Place your finger over the orifice and fill the cup with 75°F (24°C) water. Remove your finger and, with a stopwatch, measure the time it takes for the level in the cup to drop from the upper pin to the lower pin. The time should be 15 seconds. If it is longer than that, bend the pins together and check the calibration again. If it is shorter than that, bend the pins apart and check the calibration again. Continue until the time is 15 seconds.

General Instructions Fill the cup with strained adhesive and, with a stopwatch, measure the time it takes for the level in the cup to drop from the upper pin to the lower pin. The time in seconds is the Stein-Hall viscosity. Record the time and temperature of adhesive