Pigmented Intermediates

Venue: Crowne Plaza Hotel

Location: Brussels,

Event Date/Time: Mar 04, 2002
Report as Spam


All pigmented coatings such as paint are made via concentrated pigmented intermediates which may be immediately converted to final product by various let-down procedures. Alternatively the final product is produced later by factory blending, or at the point of sale through tinting or inter-mixing schemes. The properties of a pigmented coating depend on the choice and ratio of components, the particle size and distribution of pigments and the order of addition. There is therefore a strong interaction between the formulation and processing which can be reflected in differences in key properties, such as hue and colour strength, on scale-up or in changing the production route.

Processing is one of the key operations within coating production and includes the dispersion of pigments into liquids, solutions or dispersions, and in some cases molten polymers. Dispersion involves the inter-related stages of wetting, stabilisation and deagglomeration which are influenced by kinetic and dynamic factors. During deagglomeration rheology plays a key role in both energy and mass transfer. The complexity of dispersion as a process has led to much industrial production requiring multiple test and adjustment routines for quality control. However operational efficiency requires minimal adjustment, or ideally RFT manufacture.

Among the advances that have been made which aid operational efficiency in processing are new pigment grades or forms, and in particular polymeric pigment stabilisers. There have also been advances in processing equipment which is reflected in the transition from vertical to horizontal bead mills, re-circulation milling, high energy rotor stator mills and finer ceramic media. Underpinning these developments are improved seal designs and the use of computational fluid dynamics to optimise design details. Despite all this progress it is not a simple matter to make the best selection. In addition to the dispersion rate and energy intensity factors there are other considerations such as cleaning, emissions to the atmosphere, cooling efficiency, operating costs and many more. This conference will provide a forum to discuss the latest developments in all factors influencing processing and scale up and their integration into best practice protocols.