Filter paper is a semi-permeable paper barrier placed perpendicular to a liquid or air flow. It is used to separate fine substances from liquids or air. Filter paper comes in various porosities and grades depending on the applications it is meant for. The important parameters are wet strength, porosity, particle retention, flow rate, compatibility, efficiency and capacity.
Filter papers are used for the separation of solids from the liquid component of a solution. This is a technique of filtration that uses gravity to draw the liquid through the filter paper. The other is the vacuum or suction filtration technique. There are two main methods of using the gravity filtration technique.
Qualitative filter papers are manufactured from high-quality cotton liners, ensuring quality, reproducible and uniformity. With average 0.1% ash content. Qualitative filter papers are used for analytical and routine analyses, when no gravimeter analyses are required. A wide range of retention/flow rate combinations matches numerous laboratory applications.