WHC Technical Topic: Impossible web handling

By Dr. David R. Roisum

We are often asked to do the impossible. Here I do not merely mean, “fix it without changing something the boss or customer might object to.”  Rather, what you are asked to do should not or even can not be done. By this I mean that economics will not allow solutions that are more expensive than the problem itself. By that I mean, physics will not allow some problems to be solved at all within the constraints imposed by product, process or customer.

In the next few minutes of this week's video clip, we will cover a half-dozen physically impossible goals. We will begin with motors and then proceed to tension control. However, the focus will be on product/process design. Examples here include calendering, laminator curl, wrinkling and winding. Finally, we will learn how to count machine knobs, independent process knobs and dependent goals to check and see if our system is currently over-constrained.

101.90e – https://www.youtube.com/watch?v=t_6VsxvyQ4I