were conducted on a british standard drainage device tappi test procedure number t 221 om 88 determinations are made initially with various volumes of pulp furnish to determine the appropriate volume of furnish which will produce a sheet of the desired basis weight this volume is used in all testing and is agitated in a separate container at a specific shear rpm consistent with the mill 39 s processing conditions the component test dosages are added and allowed to mix for 15 seconds each this treated volume is then added immediately to the drainage device where water is then added manually to the grooved line approximately 6 9 liters total volume this slurry is then mixed with the device plunger for 4 cycles the draining lever is then depressed while simultaneously starting a timer capable of measuring to 0 1 seconds the pulp slurry will then drain from the device and is observed for fibrous mat formation on the device wire the timer is stopped when all water has drained from the cylinder to the point where the fibrous mat formed has lost its gloss or sheen simulating a dry line on a paper machine the time of dewatering or drainage is noted for all component dosages drainage times were not converted to 60 gram sq m od oven dried per tappi t 221 the fibrous mat is removed for press and oven drying and can.