Surface Roughness of Particles

Measuring the surface roughness of individual particles can now be undertaken by utilising white-light interferometry. 3DP is a non-contact surface profiling technique which is rapidly being adopted by a wide range of industries. The benefits of the technique are demonstrated in this short case study.

The surface roughness of particles is important in numerous industries where powder flow or abrasion properties need to be controlled. This ranges from the delivery of micronised pharmaceuticals via inhaler devices to the efficacy of grinding media.

CSMA were approached by a titanium dioxide powder manufacturer to determine the surface roughness difference between powder manufactured by a freeze granulation method and that manufactured by the spray drying technique. The manufacturer’s aim was to determine which production method resulted in smoother particles which could improve flow during processing of the powders into solid products.

3DP was undertaken on powders manufactured by both methods.
3DP provided 3D images of the powders:

The images show the spray dried particles have a significantly smaller mean particle size (15µm) compared with the freeze granulated samples (50µm).

From this data surface roughness parameters can be determined.

The mean surface roughness of these powders were calculated to be:
Freeze granulation 1.417μm (standard deviation 0.718)
Spray Dried 1.017μm (standard deviation 0.10)

The conclusion of the analysis was that the spray dried powder particles showed greater surface roughness homogeneity which would in turn lead to better flow of the powder.

For further details of the 3DP technique please visit the 3DP section of the web site

Or contact us at enquiries@ceram.com, tel: +44 (0)1782 764269.