Savings in time required to quadrant-fold circles to fit conical filter funnels in repetitive or multiple analyses
Decreased overall filtration time because of the extra surface area exposed; the normal slow down of filtration speed due to the loading of particulate is postponed
Increased total loading capacity as more filter area is available
Maintained flow rate due to the reduction in filter paper contact with funnel side and, the self-supporting shape of the filter itself
The prepleating does not significantly affect any of the technical data and the same figures may be used for the flat circles
Grade 2V: 8 µm
Widely used for general purpose filtration. Has excellent particle retention and a good filtration speed and loading capacity. Also available in flat stock form as Grade 2.
Grade 5V: 2.5 µm
The maximum degree of fine particle filtration in the qualitative range. Capable of retaining the fine precipitates encountered in chemical analysis. Slow flow rate. Excellent clarifying filter for cloudy suspensions and for water and soil analysis. Also available in flat stock form as Grade 5.
Grade 113V: 30 µm
Very thick and strong filter with creped surface for extremely high loading capacity, particularly in folded form. Fastest flow rate of any qualitative grade. Ideal for coarse particles and gelatinous precipitates. Also available in flat stock form as Grade 113.
Grade 114V: 25 µm
Strong filter with very fast flow rate. Ideal for coarse particles and gelatinous precipitates. Smooth surface. Also available in flat stock form as Grade 114.
Grade 287 ½
Kieselguhr paper with a medium to slow flow rate. Additional adsorption effect, e.g., for the separation of very fine semi-colloidal turbidity, for clarifying milk serum, starch solutions, soil suspensions or sugar-containing solutions prior to polarimetry or refractometry. Also available in flat stock form as Grade 287.
Grade 520 a ½: 15-18 µm
A thin paper with great wet strength and a very high flow rate. Frequently used in technical applications such as the filtration of viscous liquids and emulsions (e.g., sweetened juices, spirits and syrups, resin solutions, oils or plant extracts). Also available in flat stock form as Grade 520 a.
Grade 520 bII ½: 15-19 µm
A thick paper with high wet strength offering a very high flow rate. Also available in flat stock form as Grade 520 bII.
Grade 588 ½
Fast filter paper. Stated in a number of standards and methods, e.g., Aflatoxin determination in animal feed (BS 5766-7) and Mercury determination in sludge (EPA method 105). Also available in flat stock form as Grade 588.
Grade 591 ½: 7-12 µm
A thick filter paper with very high loading capacity for fast filtration of medium to coarse precipitates. Offers high absorbency and increased wet strength. Also available in flat stock form as Grade 591.
Grade 595 ½: 4-7 µm
Very popular, thin filter paper, medium-fast with medium to fine particle retention. Used for many routine analytical applications in different industries (e.g., particle separation from food extracts or filtration of solids from digested environmental samples, e.g., for ICP/AAS analysis). Also available in flat stock form as Grade 595.
Grade 597 ½: 4-7 µm
A medium fast filter paper with medium to fine particle retention. Used for a wide variety of analytical routine applications in different industries like food testing (e.g., determination of fat content) or removal of carbon dioxide and turbidity from beverages (e.g., beer analysis). Also available in flat stock form as Grade 597.
Grade 598 ½: 8-10 µm
A thick filter paper with high loading capacity. Combines medium retention with medium-fast to quick filtration speed. Also available in flat stock form as Grade 598.
Grade 602 h ½: < 2 µm
A dense filter paper for collecting very small particles and removing fine precipitates. Used in sample preparation, e.g., in the beverage industry for residual sugar determination, acidic spectra, refractometric analysis, and HPLC. Also available in flat stock form as Grade 602 h.
Grade 0858 ½: 7-12 µm
Grained, with medium fast flow rate and medium retention. A universal filter paper, used for the filtration of extracts, oils, beer, syrups etc., also applied in filter presses or for the aspiration of liquids. Available flat stock form as Grade 0858.
Grade 0860 ½: 12 µm
Comparable to Grade 0858 but with a smooth surface, slightly thinner and faster. Also available flat stock form as Grade 0860.
Grade 0905 ½: 12-25 µm
A creped paper for coarse particles, offers a very high filtration speed. Available flat stock as Grade 0905.
Grade 1573 ½: 12-25 µm
A fast filter paper with high wet strength. It has a very smooth surface making it easy to scrape or wash off precipitate. Resistant against: sulfuric and nitric acid solutions (up to 40% at 50°C), hydrochloric (up to 10% at 100°C, 20% at 60°C, 25% at 20°C), alkalis (up to 10% at 20°C). Also available in flat stock form as Grade 1573.
Grade 1574 ½: 7-12 µm
A medium fast filter paper with high wet strength. This paper has the same chemical resistance characteristics as Grade 1573 (see under Grade 1573 above). Also available in flat stock form as Grade 1574.
Grade 2555 ½
A medium fast filter paper. Used for the filtration of the mash for the determination of the extract in malt and wort and for removing carbon dioxide from beer.