April 20, 2022
Two of the key elements determining the performance and quality of pigment dispersions are rheological behavior and dispersion stability. It is crucial for development of a high-quality colorant to have the capability to measure and control these two properties with a high level of precision. To advance expertise in these areas, Chromaflo Technologies APAC has been investing in expanding capabilities in the evaluation and prediction of changes in rheology and settling characteristics of pigment dispersion over time, with a particular focus on predictive capability.
Dispersions are unstable from a thermodynamic point of view; however, they can be made kinetically stable for periods which determines their shelf life. This period of stability needs to be carefully understood and assessed as accurately as possible to ensure the most stable and highest quality product is the one reaching the customer and consumer. Evaluation of the destabilization process, however, can be very slow and time-consuming, potentially resulting in increased product development times. In order to evaluate stability evolution as early and quickly as possible in the development process (up to 200 times faster compared to visual testing), and to quantify formula alterations required, Chromaflo Technologies APAC has invested in the use of multiple light scattering methodology coupled with vertical scanning techniques. This approach enables fast and sensitive identification and evaluation of common destabilization mechanisms impacting pigment dispersions such as foam formation, syneresis, sedimentation, flocculation, etc.
Flow properties are also used as important quality indicators to be controlled to maintain the superior performance of pigment dispersions across various applications in the field. Traditional viscometers have limitations in the evaluation of flow properties since they only measure viscosity under single flow conditions. On the other hand, rheometers can measure rheological behavior of pigment dispersion that cannot be defined by the single value viscosity. Performing rheological profiles before and after thermal and mechanical stress regimes is a very powerful way to build confidence in a formulation in the early days of aging studies. The rheology profiles of pigment dispersions under a variety of shear rates can be used to predict the behavior of the products under different conditions—including in the field—including the variety of dispensing equipment and methods, storage, etc. with significant accuracy.
The utilization of these two experimental methodologies (in conjunction with other methods also employed) has been shown to enhance the accuracy of predictive assessment. Moreover, the valuable information obtained from these predictive tools can help develop a very clear picture of the anticipated performance of the product in the market under a variety of conditions.
Chromaflo Technologies APAC is employing these techniques to identify drawbacks of formulations as early as is possible in the dispersions development phase to achieve the final formulation of highly robust products in shorter development time without sacrificing accuracy to ensure products have the highest performance under the wide variety of application conditions found across the APAC region. So, with the focus on delivering ever-improving formulation robustness in parallel paths with ever-shortening developing cycle times, Chromaflo Technologies continues to strive to provide customers with the very finest quality products and technologies.