Two important properties related to powder drying and stability
by Dr Majid Naderi, Science Development Manager
Published 13 April 2018
In order to understand and control manufacturing operations such as milling, granulation, crystallization and powder mixing, water vapor sorption properties of the starting, intermediate or final products are key factors in understanding the particle processing operation and/or the final product performance. Vapor sorption isotherms can provide a useful picture of many particulate products and show a strong dependency on various macroscopic properties, including the flow properties of bulk particles.
The moisture sorption properties of materials are critical for their shelf-life stability and the first property to consider in a drying experiment. This is especially true for powdered products which are vulnerable to either temperature or humidity shocks. Products can cake, become sticky and collapse, thus rendering them unsaleable. The gravimetric sorption technique DVS or Dynamic Vapour Sorption may be used to rapidly assess desorption isotherms and the kinetics of moisture loss and drying of various materials. The analysis of the experimental data may be performed using the Surface Measurement Systems Advanced Data Analysis add-in suite, facilitating rapid and reliable evaluation of the drying conditions.
Second, surface energy heterogeneity of crystalline solids is directly related to the cohesive nature (i.e. powder-powder interaction) of the powder. Understanding the cohesive nature of powders is vital for the successful development, processing, and storage of a wide range of materials. Various factors can change the rheological properties of powders, such as particle size, shape, surface texture, and compliance, but changes in surface chemical environment is often overlooked when determining the flowability of a particular powder. For this, Inverse Gas Chromatography Surface Energy Analyser is the perfect tool to use to understand the surface chemistry and performance of many particulate products and processes.
Below are some of application notes related to powder drying and stability:
Application note 11 – Moisture Stability of Powdered Milk Formulations
Application note 102 – Moisture Sorption Properties of Food Products and Packaging Materials Studied by DVS
Application note 224 – Surface Energetic Heterogeneity Profiles by iGC Surface Energy Analyzer