Dv50 is the median of a volume-weighted particle-size distribution. It identifies the reported diameter below which 50 percent of the measured particle volume falls.
The “v” matters. Half the particle volume is not necessarily half the number of particles, and a volume distribution is not automatically a mass distribution when a blend contains materials of different densities.
Read the weighting before the number
Larger particles contribute much more volume per particle than smaller ones. A powder can therefore contain many fine particles while a smaller number of coarse particles account for a substantial volume fraction.
The reported diameter also depends on the sizing method. Laser diffraction interprets scattering through a model and reports equivalent spherical sizes rather than measuring every particle’s longest physical dimension.
For flakes or elongated particles, that equivalent diameter cannot describe all dimensions relevant to passage through an opening.
A median is not an upper limit
Particles larger than Dv50 remain part of the distribution. Two samples with the same median can have different distribution widths and different coarse tails.
Dv90 and Dv99 describe higher cumulative percentiles. They help describe those tails, but neither value is the maximum particle size: some measured particle volume remains above each percentile.
A report intended to address oversize material therefore needs the relevant distribution information and measurement conditions, rather than a median relabeled as a ceiling.
Dispersion matters as well. A measurement made after breaking up agglomerates can differ from one that retains them. The report should identify the preparation and dispersion used.
Why the sifter needs a separate evaluation
A jar sifter is part of a dispensing system. Its operation involves the powder bed, openings, fill level, handling motion and intended way of collecting powder.
An equivalent spherical size does not directly establish whether a flake will orient through an opening or whether cohesive particles will form an agglomerate during storage.
Opening shape, clear aperture and open area are also different specifications. With flexible mesh, its fitted condition can change the openings presented to the powder.
Packaging sample showroom.
An aperture selected from Dv50 alone therefore has no established relationship to the desired dose or handling experience.
Connect the report to the actual pack
For a loose-powder packaging project with SamBound New Material Technology Company Ltd., the container options shown at sambound.com provide product context. They do not provide a universal particle-size-to-aperture conversion.
A useful comparison combines the powder’s distribution and preparation record with the actual sifter and jar assembly. Keep the fill and handling conditions comparable when observing delivery.
The result to assess is how that powder passes through that fitted sifter under the intended handling conditions. Dv50 contributes information to the comparison without replacing it.
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SamBound New Material Technology Company Ltd.