Solids Solutions: the specialist in powder and particle technology

Solids Solutions (also known as Delft Solids Solutions B.V.) is a leading contract research organisation based in Wateringen (near Delft), specialising in the physical characterisation of solid materials such as powders and granulates. With over 40 years of experience, the company analyses and improves properties such as porosity, surface area, particle size and powder behaviour. Customers from sectors such as pharmaceuticals, food, chemicals, cosmetics and building materials can count on customised services, ranging from analyses, consultancy services and innovative material development to the design of new equipment and methodologies.

What makes Solids Solutions unique?

The strength of Solids Solutions lies in the combination of research facilities and expertise in the field of bulk solids, powder measurements and process development. They have advanced laboratory setups for investigating flow, cohesion, segregation, dustiness, shear and particle strength. Their services include powder processing operations such as mixing, grinding, granulation, coating and pneumatic transport — from laboratory to pilot scale.

Thanks to their own process equipment — including mixers, granulators, and screening installations — and advanced characterisation techniques (e.g. the new PT-X powder flow tester), they offer complete support from material analysis to process engineering and design.

Mixing process: mixing solids

Mixing solids in powders is more complex than mixing liquids. Solids Solutions considers powder mixing technology to be a craft: with solids, mixing only occurs through mechanical action such as shaking, tumbling, vibration or high-shear processing.

The three main mechanisms of powder mixing – convection, diffusion and shear – ensure that components are dispersed through movement, individual particle displacement or slip plane formation within the mass. At the same time, undesirable de-mixing or segregation (e.g. fine vs coarse, light vs heavy) can occur, reducing homogeneity.

Solids Solutions offers various types of mixers — from cube mixers (2–12 L), convective mixers (5–20 L) to high-shear mixers (1–6 L). These can be used to effectively mix both free-flowing and highly cohesive materials. High-shear mixing often results in short mixing times and high homogeneity, especially with materials that are difficult to mix or rich in agglomerates.

For optimal quality, mixing is supported by representative sampling, segregation analysis and particle characterisation. This allows the degree of homogeneity to be assessed objectively.

Process development: milling powder

In addition to mixing, Solids Solutions offers advanced support for the milling powder process, i.e. reducing the size of particles by grinding. In the context of material development and unit operations, grinding powder plays a key role in adjusting particle size, porosity and the final product performance.

Powder milling encompasses various technologies such as ball mills, hammer mills, impact mills and air classification. Solids Solutions has the infrastructure to apply and optimise these techniques on a laboratory and pilot scale. By linking the results to properties such as surface area, porosity and flow behaviour, tailor-made solutions are created that meet specific industrial needs.

The aim of grinding processes is not only to reduce particle size, but also to improve product quality, storage behaviour, miscibility and end performance. By fine-tuning process parameters such as energy input, retention time and efficiency, they help customers develop robust and consistent production processes.

Applications and education

Delft Solids Solutions also offers high-quality courses such as “Powders & Granules – Processing and Unit Operations”. These courses cover unit operations such as mixing and grinding in detail, with a focus on practical choices of equipment and production parameters (such as powder size, shape and density).

Their activities in consultancy, troubleshooting and knowledge sharing are aimed at helping industries optimise powder processes – from the laboratory to the factory floor.