Authors: Xiaoming Zhao, George Stylios
The peak stress value (PSV) at the interface between a coating polymer solution and a fabric during coating has been calculated using generalised Navier-Stokes and Carreau models for non-Newtonian flow. The model suggested that knife gap is the most important machine parameter affecting the coating process. A 20% decrease in knife gap for example leads to 100% increase in PSV in the coating paste, which subsequently can lead to poor adhesion between the paste and the fabric during coating. Coating speed was found to have less effect on the PSV, a 50% increase in speed leading to only a 30% increase in PSV, implying that this factor is less significant. The validity of the rheological models was confirmed by experimental investigations. Kew words Modelling, simulation, non-Newtonian flow, fabrics, coating