Cellulose filter papers
Filter papers from cellulose are the most used filters for all kinds of applications in laboratory, technical and industrial filtration. Generally, two types of filter papers are disinguished.
- Qualitative filter paper
- Quantitative, ashless filter paper
Qualitative filter paper
Qualitative filter paper is the standard paper which is suitable for most applications. It is used in general laborary filtration, e.g. for the determination of dry matter or clarification of liquids. Qualitative filter papers are available as circles and pre-folded filter. All grades can be found here.
Quantitative, ashless filter paper
Quantitative filter paper, also called ashless filter paper, is acid-washed and has an extremely low ash content (< 0.01 %). It is used for ignition residue testing or for contatmination-free filtration. Available products can be found here.
Hardened filter paper
Qualitative and quantitative filter papers are both available as hardened versions. These papers are wet-strengthened and therefore, exhibit a high mechanical stability in wet condition. They are particularly suited for applications, where the residue is removed from the filter with a spatula. They are often used for quantitative routine procedures and analytical gravimetric analysis.
Filter paper is available in different surface structures.
- Smooth - standard
- Crepped - higher stability and faster filtration
- Embossed - larger surface area
Smooth surface
Crepped surface
Embossed surface
Available dimensions and formats
MACHEREY-NAGEL filter papers made from cellulose are available in different formats and sizes. If a product is not available in the webshop, please do not hesitate to contact us!
Many other sizes and cuts are available on request.
Technical parameters of filter papers
Ash content / residue on ignition
The ash content is determined in accordance with DIN 54370: 10 g filter paper are weighed after ignition in a platinum crucible at 800 °C. Results are expressed as % of original paper weight.
Basis weight
The basis weight is determined for a sample of 10 x 10 cm. It is measured in g/m².
Filtration speed
For determination of the filtration speed in accordance with DIN 53137 the duration of flow of 10 mL distilled water through a quadrant-folded, freely suspended filter circle of 12.5 cm diameter is measured. Results are expressed in seconds.
Thickness
The thickness of a paper is measured with a touch pressure device. Especially for soft and creped papers it is important that the touch pressure is not too high. Otherwise the papers are compressed and a falsely low thickness is obtained.
Particle retention
Particle retention refers to the efficiency of filter papers in retaining certain precipitates. It is characterised by the permeability of the paper for precipitates of iron(III) oxyhydrate, lead sulfate, calcium oxalate and barium sulfate.
