Powder Flow Analyser case studies

Evonik Industries is the second largest chemicals company in Germany, and one of the largest speciality chemicals companies in the world.

The challenge

Evonik needed to develop a testing procedure to allow accurate and repeatable caking and flow assessment of their AEROSIL and SIPERNAT products which contained silica. By definition, these powders are much more free-flowing than standard powders and granules and even compressed samples are relatively unstable and easy to disturb when being loaded onto testing instrumentation.

The research

They developed a special rig which allows a prepared sample to be loaded onto their Powder Flow Analyser avoiding any potential damage to the compacted structure before the test begins. As a global supplier of specialty chemicals for the food, feed, pharmaceutical and chemical industries the new test allows the identification of the most appropriate flow agent for a particular application.

The outcome

This enabled the specification of addition levels to control clumping and crusting behaviour and to maintain free-flowing powders which are easier to handle and process.

The Food and Drug Administration is responsible for protecting public health by ensuring the safety, efficacy, and security of human and veterinary drugs, biological products, and medical devices; and by ensuring the safety of the US nation's food supply, cosmetics, and products that emit radiation.

The challenge

At the AAPS in 2008 researchers Shah, Tawakkul & Khan from the Division of Product Quality Research at the Food and Drug Administration presented their findings on the evaluation of powder flow by compendial and non-compendial methods, with help from the Powder Flow Analyser by Stable Micro Systems. The objective of their work was to carry out an evaluation of flow of pharmaceutical powders and granules. The understanding of their flow is crucial during mixing, packaging and transportation. Different grades and concentrations of magnesium stearate and granules prepared by various methods were used in a model formulation.

The research

Angle of Repose, Bulk & Tapped Density, Carr’s compressibility Index, and Hausner Ratio were the traditional Compendial methods employed whilst the Non-Compendial method of using a Powder Flow Analyser for the attribute measurements of Cohesivity Index, Caking Strength and Flow Stability were compared.

The outcome

The researchers successfully carried out an evaluation of flow of pharmaceutical powders and granules.

Since 1896, Nutricia have changed lives for the better through leading-edge nutritional science and expertise. They offer innovative nutritional solutions that positively impact the health of people with specific nutritional needs at key moments in life, from the first 1000 days and onwards to into old age.

The challenge

Powdered infant formula is now produced by over a dozen businesses in 40-50 manufacturing sites across the world. These formulations must adhere to stringent standards that permit the use of only a small number of constituents that must or may be present within specific ranges. Any deviations from the regulatory nutritional requirements must be reported to the regulatory organisations, which have the right to enforce compliance if necessary. The main obstacles that infant formula makers confront in their attempts to emulate human milk are those related to nutritional and microbiological qualities of newborn formula. However, there are concerns about nutrient imbalances and powder flow properties.

The research

Some of these problems are easy dosing by preventing clumping and ease dissolving of the powder in water which is related to a particle structure and size distribution. This remains to be a challenging task for the manufacturers as both moisture and fat present in infant formula potentially contribute to caking. A tool for the measurement of powder flow to assess formulation changes and the effects on powder flow properties is a welcomed solution to the development challenge.

The outcome

Nutricia used their Powder Flow Analyser to assist in the filing of their patent entitled ‘Infant Formulae and their Preparations’.

The International Advanced Research Centre for Powder Metallurgy and New Materials in Hyderabad is a state-of-the-art facility for research and development in advanced materials and associated processing technologies.

The challenge

Uniaxial die compaction of ceramic powders is one of the widely used forming processes. The quality of the compact depends significantly on the flow properties of the powders or granules which in turn strongly affect the powder processing conditions.

The research

With the aid of their Powder Flow Analyser, scientists have been attempting to elucidate and to correlate the compaction behaviour of Magnesium Aluminate spinel powder as well as granules formed from the powder particles. MGAl₂O₄ spinel is one of the emerging polycrystalline transparent ceramics which possesses superior properties for various optical applications. The flowability and diametral compression testing results of the compacts will assist in quantifying the physical properites of this powder to define its uses in this market.

The outcome

The Powder Flow Analyser enabled the prepared of a guide: 'Compaction Curves: A Tool for Qualitative Evaluation of Quasi-static Compaction Behaviour of Ceramic Powders' which can be used in the industry.

Teff (Eragrostis teff) is a cereal staple grain from Ethiopia and Eritrea in Africa and is the smallest grain in the world. It is ground into flour and often fermented to make a flatbread called injera.

The challenge

Recently Teff has been attracting the attention of the modern food industry, since it is a gluten-free grain encompassing highly appreciated nutritional advantages. As a relatively new raw material, little information on its handling and processing properties is available.

The research

Flowability, water sorption characteristics and thermal properties of flours from three Ethiopian Teff varieties were studied at the University of Valladolid with the aid of a Powder Flow Analyser. Wheat (whole and refined) and rice flours were included as references.

The outcome

Teff flours were less flowable than the reference flours and their flow properties were more sensitive to water activity changes. Quantitative assessment such as this will assist in the evaluation of such grains as suitable wheat flour substitutes in this field of growing product development interest. Read more about this research.

The term “minitablets” commonly refers to compressed tablets with size smaller than typical tablets with diameters between 1-4mm.

The challenge

Scientists from the Medical University of Gdansk have been investigating the use of novel tools for the assessment of powders and granules flow properties and for the analysis of the minitablets compression process. The purpose of this study was to apply rheological measurements to assess the flow properties of powders and granules and to compare the results with the standard pharmacopeial tests.

The research

Insights were provided regarding the methodology of rheological properties of powders and granules using a Powder Flow Analyser. Pharmacopeial methods and rheological tests using the PFA were performed to assess the flow properties of designed powder and fractionated granule mixtures – placebo and with benzodiazepines. Compression of 2.5 and 3 mm minitablets was carried out and the compression force registered during the process and weight uniformity were statistically analysed.

The outcome

The flow rate measurement and cohesion test on the PFA resulted in the best differentiation between mixtures. This study showed that the flow properties are the critical quality attributes determining the performance of minitablets compression. Find out more

‘Influence of functional ingredients, packaging material and storage time on physical properties of newly formulated, enriched instance coffee powders’ is a paper published at the Univeristy of Zagreb.

The challenge

Consumer demands for healthy, functional foods are growing rapidly nowadays. Coffee, as one of the most widespread commodities, represents an interesting aspect of enrichment, since it is consumed by millions of people on a daily basis.

The research

The aim of the study was to formulate enriched instant coffee powders with the purpose of estimating the influence of storage time, functional ingredients and packaging material on physical and sensory properties of the mixtures.

The outcome

Using their Powder Flow Analyser, researchers were able to establish that change in packaging materials has a significant effect on the cohesion of the coffee. This will have a detrimental effect on useability for the consumer and ultimately affect product satisfaction and repeat purchase. Find out more

Roasting degree and particle size are two major parameters that affect the mixture homogeneity of powdered food mixtures.

The challenge

Researchers from Ericiyes University (Turkey) investigated powder caking and cohesion behaviours of coffee powders as affected by roasting and particle sizes, using principal component analysis for flow and bioactive properties.

The research

This study focused on the flow properties of powdered coffees regarding their roasting degree (light and dark roasted) and particle sizes for aiming to assess the flow and physicochemical properties of coffee and the relationship with the bioactive, sensory properties and flowability. They used their Powder Flow Analyser to perform cohesion, caking and powder flow speed dependency tests to determine the flow properties of coffee samples.

The outcome

Differences in processing conditions of coffee were found to have a strong effect on the powder flowability, particularly at the smallest particle size. Read more