Fluting Filter Paper

“Fluted “ filter paper (LEFT) is used when you wish to separate a liquid and a solid, keeping the liquid and discarding the solid. This arrangement of folds in the filter paper will allow the liquid to pass through it very quickly and give you a lot of surface area on which to collect the solid “impurity”.

If you wished to keep the solid sample and discard the liquid, you would make a simple cone of the filter paper (RIGHT). This would make it much easier to remove the solid from the filter paper than if it was on a fluted filter paper.

To “flute” filter paper, you do the following:

Fold the large circle of filter paper in half (2), then in quarters (3) being careful not to press the creases too hard as this tends to weaken the paper and cause possible tears later on.
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Take the straight edge on one side and fold back to the centre fold (4). Do the same on the other side (5). You should now have a “fan” with alternating folds. Open the “fan” up with the centre fold going away from you (6).
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Starting at one side, fold the straight edge up towards the first fold (7). Fold back along the preformed fold and then fold again towards the centre fold (8). Reverse the direction of the centre fold (9). Continue folding back and forth until you get another smaller-sized fan. ( 10, 11, 12)
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Open the “fan” and look for the two areas called the “boxes”, where there are two folds going in the same direction instead of alternating (13). Pinch the paper (14) to make another fold between the two folds in each box (15). Then invert the filter paper before you place it in the glass funnel. [NOTE: inverting the filter paper will insure that any grease or dirt transferred from your fingers will be on the “inside” of the filter paper rather than the “outside”, when it is being used. Whatever is collected on the inside of the filter paper is something that will be disposed of.]
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