ADSORPTION: The natural phenomenon of a gas, vapor, or liquid being attracted to and held on the surface of a solid.

AUTOCLAVE: Sterilizing apparatus that uses steam at high pressure.

BRIDGING: A condition of filter element loading in which contaminant spans the space between adjacent sections of a filter element, thus blocking a portion of the useful filtration area.

CENTIPOISE: One one-hundredth of a poise. A poise is the unit of viscosity expressed as one dyne per second per square centimeter.

COALESCER: A mechanical device, which unites discrete droplets of one phase prior to being separated from a second phase. Can be accomplished only when both phases are immiscible. Requires a tight media which is preferentially wettable and, by its nature of being tight, the media is also a good filtering material. Good coalescing permits gravity separation of the discontinuous phase.

DILATANT: A flow condition where certain liquids will show an increase in viscosity as the rate of shear or flow volume is increased.

DROPLET: A minute drop, which mates to form larger drops capable of falling by gravity.

EMULSIFICATION: A dispersion of one substance in the form of minute drops within another substance.

ENTRAINMENT: Mist, fog, or droplets of a liquid that are usually considered to be a contaminate when used in the filtration industry.

FILTRATE: Filtered fluid that flows out of a filter.

HYDROPHILIC: Water accepting or water wetting. Having an affinity for water. Capable of uniting with or dissolving in water. Effective coalescing requires a media to have hydrophilic characteristics which cause free or entrained water to commingle into droplets which, when mated with other droplets, form into drops which separate by gravity. Opposite of hydrophobic.

HYDROPHOBIC: Non-water wetting. Having an antagonism for water. Not capable of uniting or mixing with water.
Hydrophobic features are induced in the process of cellulose manufacture. Opposite of hydrophilic.

IMPINGEMENT: The direct high-velocity impact of the fluid flow upon or against an internal portion of the filter.

IMPREGNATION: Process of treating a coarse filter medium with resins.

KARL FISCHER: Analytical method of determining amount of water present in a sample by titration.

NEWTONIAN: A liquid that does not change in viscosity with a change in rate of shear, agitation or flowrate.

SURFACTANTS: Coined expression for surface-active agents, which are sometimes called emulsifiers or wetting agents. First appeared in hydrocarbons with the advent of the catalytic cracking process in refining. Caused by the forming of sodium sulfonate and sodium naphthanate molecules. Affects liquid/liquid separation by reducing interfacial tension and forming into a slime, which binds off the fibers used in coalescing media.

THIXOTROPIC: A liquid that shows a marked reduction in viscosity as the rate of shear, agitation or flowrate is increased.

TURBIDITY: Stirred up sediment or contaminant in a fluid.

VISCOSITY: Degree of fluidity; property of fluid’s molecular structure by virtue of which it resists flow. The resistance of flow exhibited by a liquid resulting from the combined effects of cohesion and adhesion. The units of measurement are the poise and the stoke.

The terms and definitions for this glossary were provided by Rosedale Products Inc., a technology developer in the field of liquid filtration systems and waste minimization products.