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)].
- 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.
These extremely strong filter papers have a high wet strength due to the addition of a small quantity of chemically stable resin. Normal qualitative applications will not introduce any significant impurities into the filtrate. The resins do, however, contain nitrogen so these grades should not be used in Kjeldahl estimations, etc. Some wet strengthened grades are available in folded (prepleated) forms.