Folding

Quadrant-Folded Filter Paper

Why folding or buying pre-folded filter paper instead of using flat discs?
Flat funnels increase filtration speed using a vacuum pump while conical funnels simply use gravity. Flat discs are suitable for both flat (Büchner, Hartley or Hirsch funnels) and conical funnels. So the choice depends on the application or available funnel. While you can always fold a flat disc into a conical shape, if you have a lot of recuring analyses to perform, buying pre-folded filter can save you the folding time.

Grade 1 folded Grade 2 folded Grade 4 folded

Quadrant-Folded shapes

Quadrant-Folded filters have a cone shape so they fit standard connical funnels (58 or 60°), not Büchner or Hirsh funnels.
There are a few variations in folding of the shape:

  • asymetrical cone (all folds on one half)
  • symetrical pyramid (folds are on opposite sides)
  • asymetrical pyramid (folds are adjacents)
  • custom folding (see fluting)

Discs sizes

Before folding the discs, we cut them starting from rolls or sheets. This allow us to cut any diameters.
Here are some example of the most common diameters we fold:

Sugar Industry
⌀210, 215, 225, 250 mm | 10 in

Packaging

Our designers can arrange any custom printing, packaging and labeling as an integral part of our Private Label offer.
If you prefer we can also use standard white boxes developped for our clients. We make sure the box sizes match the different diameters, folding and filter paper thickness.
Some examples:

  • stacked opened by 250 or 500 in a hot shrink sleeve
  • flat in a box by 250 or 500 with dividers
  • custom box / distributors