Web20180a - Time Constants - Intro

Time constants are not only useful in many of the general sciences, they can also be a useful concept in certain web handling applications. The product/process designer can take these concepts even further and use them to quantitively predict how long the web or wound roll will take to stabilize to a new condition. In this series we will cover topics as varied as moisture and temperature change in both the web and wound rolls, as well as wound roll shape, bagginess and more. My 10th book, the must-have, 750 page, Web Handling Handbook, is available through Destech as both print and e-book. https://www.destechpub.com/product/web-handling-handbook/ https://www.youtube.com/watch?v=u3gA8RmTARA You can buy unlimited lifetime access to nearly everything I own copyright to. This includes some 500 videos, including my two-day web handling and two-day winding courses, 400+ short clips on web handling, converting, winding, machine/control design, and industrial problem solving. It includes two searchable databases listing nearly everything published except patents. Finally, it also includes thousands of other pages of reference materials, all for only $2K US. Bonus Material I first used time constants in web handling to model moisture changes in a wound roll of paper in storage. See my original paper: Roisum, David R. Moisture Effects on Webs and Rolls. Tappi J., vol 76, no 6, pp 129-138, June 1993. Alternatively, you can view the diffusion process in a wound roll beginning at 14:00 at https://www.youtube.com/watch?v=I7GviDV-IeA