Satish Kumar, Principal Investigator

Gravure Coating and Printing Technologies

Gravure coating and printing are processes that are capable of producing thin coatings or fine patterns on substrates at high speeds by using a cylinder engraved with grooves (for coating) or cells (for printing). Gravure technology is already well established, but the controlling phenomena are not adequately documented. A complete understanding of the flow in gravure grooves and cells is vital for the prediction and optimization of coating and printing processes.

In gravure operations, the engraved cylinder is often used in conjunction with a smooth deformable cylinder in order to get thinner coatings and to avoid wear of the engraved cylinder’s surface. These researchers’ objective is to model the flow between a gravure groove/cell and a deformable roll. Because the gap between the two cylinders is usually so small that the flow is essentially one-dimensional, lubrication theory may be applied. The pressure distribution in the gap is governed by a very stiff nonlinear ordinary differential equation (ODE), whose solution requires special integration algorithms. Previous work by others on similar ODEs indicates that the International Mathematical and Statistical Library routine dgear, a variable-order predictor- corrector method, is suitable for solving such stiff systems.

The results of the calculations this group is running on the Supercomputing Institute’s workstations will yield information about how pressure distribution, flow rates, and surface separation profiles in the cylinder gap depend on groove/cell geometry. This information can then be used to optimize groove/cell design, something that is of great interest to companies engaged in gravure operations. The results obtained with the simplified model will be compared to observations obtained from flow visualization experiments, as well as to more detailed finite-element calculations.

Research Group

Xiuyan Yin, Graduate Student Researcher