Optimisation of machine components in thermal bonding process of nonwovens: Effect of the conveyer belt on the porous web performance

A complementary study to our previous research to aid in the optimisation of the thermal bonding machine components for improved thermally bonded nonwoven production is introduced. The effect of the conveyer belt on the nonwoven’s thermo-fluid flow behaviour is investigated in detail. A hybrid model consisting of the discrete conveyer belt geometry and the continuum porous nonwoven web, is presented. A comparison study to predict the thermal and flow field differences in 3D and 2D formulations of the same problem is elucidated. The thermal and fluid flow distributions within the conveyer belt, nonwoven and the air domain are predicted with particular focus on the conveyer belt component of the Low & BONAR pilot machine. It has been shown that the developed 2D model provides accurate results for the conveyer belt temperatures. The three-dimensional flow effects on the thermal boundary have been predicted. The 3D approach is shown to be superior in depicting the wake behind the central conveyer belt thread. The amplitude of the wavy geometry is determined to be introducing different degrees of geometric three dimensionalities in the wake. The industrial partner Low & BONAR (former COLBOND bv.) provided technical data for the nonwoven and machine components.