Bristow Wheel

Absorption Tester

Laboratory instruments designed for paper testing measure the high-speed sorption behavior of liquid into a moving substrate under controlled contact times. The bristow wheel achieves this by releasing a known volume of fluid from a stationary applicator onto a strip of paper mounted on a rotating wheel. This configuration calculates the absorption coefficient from the resulting trace length across various wheel speeds.

Dynamic Behavior

Print run operations require precise control over the initial milliseconds of ink contact to prevent offset and feathering. The contact time on the bristow wheel can be adjusted to fractions of a second to match the speed of a commercial press. Liquid enters the porous structure of the sheet under the combined forces of capillary action and hydraulic pressure.

Fluid Interaction

Converting processes on high-speed gluer lines demand rapid water removal from adhesives to form a secure bond. When the test fluid is applied at high wheel speeds, the paper surface must absorb the moisture quickly to avoid adhesive failures. This method provides critical data for optimizing coat weights and drying rates in industrial packaging plants.

Operators run the test at multiple speeds to map the sorption profile across a range of contact times. That profile dictates the machine speed limits during the actual manufacturing run.