Friday, November 02, 2007
Paint products: Accelerated stability and quality testing
Part I: Direct measurement of separation and segregation by multisample analytical centrifugation
Scope
To assure continued consumer satisfaction the following stability issues of paint products have to be minimized or avoided:
- syneresis - separation of the liquid dispersion media
- Pigment segregation - change of colour composition inside a container
- Particle segregation - change of particle size distribution inside a container
These stability issues have to be addressed not only during development of new paint products but also for quality assurance during production on a regular basis. This application note demonstrates that multisample analytical centrifugation can be used as an efficient tool for the accelerated evaluation of separation stability of paint products.
In addition this technique provides for high resolution data of particle size distributions of pigments or emulsions.
In part II the application of multi-sample analytical centrifugation for optimization of deagglomeration of pigment particles will be addressed.
Formula V - Formulation Science and Technology 2007
' Formulating opens the way for tailoring products for specific applications and combining components with often contradicting properties. Formulation science and technology is a core discipline for industries and applications like home care, cosmetics, plant protection and coatings but also of emerging importance in fields like electronics, composite materials and biomedical technology.'
Poster contributions
Accelerated screening of formulations towards freeze-thaw stability
The formulation of dispersion based products as well as process development/monitoring and quality assurance require efficient and objective analytical tools for shelf life prediction and stability determination. Freeze/thaw stability is often used as measure of long term stability. On the other hand high freeze/thaw stability is often required as a material property. To this end the potential of multisample analytical centrifugation was evaluated as an accelerated test procedure.
Thickener performance traced by multisample analytical centrifugation
Polymeric thickeners are important ingredients to adjust flow properties and stability of formulations. The effect of polymeric additives on dispersion properties is rather complex (viscosity of the continuous phase, adsorption and depletion effects, interaction with other ingredients). Therefore optimum formulation requires extensive experimental investigations.
