Drying of Coatings and Other Applications with GARField

Drying of Coatings and Other Applications with GARField 

The relatively low entry level instrumentation cost and the relatively simple experimental methods associated with GARField - both comparable to a standard bench-top relaxation analysis spectrometer as commonly used by the food industry, for example, for water/fat ratio determinations - offer potential advantages to the industrial based user. Indeed, the overwhelming majority of the applications development work described here has been carried out in collaboration with major multi-national industrial corporations such as ICI Paints, Unilever and Uniqema, with industry sponsored research laboratories and associations such as Traetek, and with a range of small-medium sized enterprises. 

The field orientation allows the excitation field, Blr of the sensor also to be oriented in the vertical direction parallel to the gradient. This differs from the situation in STRAFI. The advantage of the GARField layout is that a B1 excitation/ sensor coil can be made from a small surface winding below the sample, able to excite/sense a well defined central region of the sample away from edge effects. 

Detailed quantitative analyses of the data allowed the production of a mathematical model, which was able to reproduce all of the characteristics seen in the experiments carried out. Comparing model profiles with the data enabled the diffusion coefficients of the various components and reaction rates to be estimated. It was concluded that oxygen inhibition and latex turbidity present real obstacles to the formation of uniformly cross-linked waterborne coatings in this type of system. This study showed that GARField profiles are sufficiently quantitative to allow comparison with simple models of physical processes. This type of comparison between model and experiment occurs frequently in the analysis of GARField data. 

A separate approach to the problem of VOC release during film formation is the use of polymer films cast from aqueous emulsions. Alkyd emulsions in particular have been proposed as new environmentally friendly paints and have therefore 

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