Filter paper

The important parameters are wet strength, porosity, particle retention, volumetric flow rate, compatibility, efficiency and capacity.

[1]: 113  Some heavy duty qualities are made to be rinsed and thereby extend the life of the filter.

[2] The raw materials (pulp) for the filter paper are coarse long fiber, often from fast growing trees.

Most notable are the (paper) coffee filter systems introduced by Melitta (1908, 1932, 1936, 1965), Chemex (1941) and Hario (2004).

[1]: 114 Horizontal plate filter paper is commonly utilized in industrial processing.

Filter papers for lubrication oils are impregnated to resist high temperatures.

[1]: 113 Filter papers are widely used in laboratory experiments across many different fields, from biology to chemistry.

Generally, filter papers are used with laboratory techniques such as gravity or vacuum filtration.

[6] Grade 1 qualitative filter paper has the pore size of 11 μm.

This grade of filter paper is widely used for many different fields in agricultural analysis, air pollution monitoring and other similar experiments.

This filter paper is used for monitoring specific contaminants in the atmosphere and soil testing.

It is very useful as rapid filter for cleanup of geological fluids or organic extracts during experiment.

During the manufacturing, producers use acid to make the paper ash-less and achieve high purity.

Quartz fiber filter paper has a high resistance to chemicals, does not absorb NOx and SOx dioxides, is unaffected by humidity and is easily sterilized.

[12] Polytetrafluoroethylene (PTFE) filter has wide operating temperature (−120 °C ~ 260 °C) with high air permeability.

The resistance to high temperature makes PTFE filter paper suitable for use in autoclaves.

It is often used to filter hot oils, strong solvents and collecting airborne particulates.