A dense pre pleated filter paper for collecting very small particles and removing fine precipitates.

• 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 pre pleating does not significantly affect any of the technical data, and the same figures may be used for the flat circles.

Time-saving Hydocs qualitative grades are offered in this convenient form, which gives major advantages over flat circles.