Methodology to estimate the yield stress applied to ultraconcentrated detergents as model systems

- Two gel detergents have been studied to estimate yield stress using different methods.
- The systems may be considered as different models due to its different flow behaviour.
- Yield stress value depends on the methodology followed to estimate it.
- The system, the purpose and the test time are the keys to select one specific method.

Two commercial highly-concentrated detergents have been studied as model systems in order to estimate the yield stress using different methodologies. Both exhibit clear viscoelastic properties with long relaxation times; the elastic component being dominant on the viscous one. They show different yield stress and time-dependent flow properties.While one of them exhibits apparent thixotropy, the other shows a thixotropy/antithixotropy transition, which predicts the occurrence of complex shear-induced microstructural transitions and the need to strict process control. Their flow curves illustrate the different fluidity of both gel detergents, which show standard shear thinning and “very shear thinning” properties, respectively.

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