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An Introductory 1D Wound Roll Model Code
Many of you have little or no access to winding models. Enclosed with this book you will find a CD that
has an introductory code called WINDaROLL written in visual basic in the background of Microsoft
Excel®. If you wish to run these codes you will need to set the level of macro security inside Excel to
levels that will allow the program to execute. In Excel select the Tools menu. It will drop down and one of
the choices will be Macro, please select that. Next amongst the list of choices under Macro you will find
Security, please select that. Now you are given a choice of security levels, please select Medium.
Whenever you attempt to run WINDaROLL a selection box will appear asking you if you wish to enable
the macros, you will have to select Enable Macro if you wish to run the code. This setting has now been
made in Excel and will appear every time you open a file that has a macro attached to it. You should
evaluate each time you open a file in Excel that has macros attached to it whether you wish to enable the
macros or not. Macros are sometimes used to spread computer viruses so users should always beware of
what macros they are enabling.
The code prompts you for the required input data by shading the required cells blue. You will find that,
depending on the options you select, that different cells will have the blue color. This code will allow you
to make 1D model computations with simplistic algorithms for wound-in-tension for center winding, center
winding with a nip, and surface winding. It will also allow you to study the effects of air entrainment and
thermoelasticity. Again simplistic algorithms have been employed in the model, for instance the
hydrodynamic nip air film expression is used rather than the more complex elastohydrodynamic
expression, but the influence of entrained air is seen both in the radial modulus and the wound-in-tension.
The code is setup allowing one set of British Engineering units and one set of SI for input. You may find
some of the input units awkward, for instance in SI units you will find yourself providing the input for
caliper in units of centimeters. Do not attempt to alter these units, their choice was a compromise and their
use is intertwined throughout the code.
With this code you can examine the effects of winding tension and nip force profiles, linear tapers are
programmed for each variable. You can study constant tension versus constant torque which was explained
in Chapter 7. You can study how different winder types will wind a given web which was discussed in
Chapter 9. You can explore the effects of air entrainment that were presented in Chapter 10. Your selection
of winder type will determine what air entrainment expressions are employed. You can also study the
effects of thermoelasticity that were presented in Chapter 11. If you wish you can also study the effects of
hygroscopic activity if you replace the thermal expansion coefficients with hygroscopic expansion
coefficients for the web in the radial and circumferential directions and the hygroscopic expansion
coefficient for the core. The change in temperature will become the change in moisture content. This is
possible because the formulation of the thermoelasticity model and the hygroscopic roll model are
identical.
At the time of this writing these codes have been checked out and found to be functional on Microsoft
Excel 2003 for Windows® and on Microsoft Excel for Mac OS X® on the Apple Macintosh® operating
system. The code will not execute correctly in its entirety in OS 9. It is also my experience that you will
find the code executes much slower on the Macintosh version of Excel. On a laptop PC with modest
computing power I have found that 1000 laps will wind in less than 5 seconds.
The example which the code will run if you execute it with the as saved inputs is for the fine coated paper
wound at constant tension at 500 psi or 3.45 MPa. These results were shown in Figures 7.2a and b.
Software Disclaimer
The software provided with this book is provided ’as is’ without warranty of any kind, either express or
implied, including, but not limited to, the implied warranties of fitness for a purpose, or the warranty of
non-infringement. Without limiting the foregoing, the authors makes no warranty that:
i. the software will meet your requirements
ii. the results that may be obtained from the use of the software will be effective, accurate or reliable
iii. the quality of the software will meet your expectations
iv. any errors in the software will be corrected.
This software and its documentation that have been made available:
vi. could include technical or other mistakes, inaccuracies or typographical errors.
vii. may be out of date, and the authors make no commitment to update such materials.
The authors assume no responsibility for errors or omissions in this software or documentation.
In no event shall the authors be liable to you or any third parties for any special, punitive, incidental,
indirect or consequential damages of any kind, or any damages whatsoever, including, without limitation,
those resulting from loss of use, data or profits, whether or not the authors have been advised of the
possibility of such damages, and on any theory of liability, arising out of or in connection with the use of
this software.
The use of this software is done at your own discretion and risk and with agreement that you will be solely
responsible for any damage to your computer system or loss of data that results from such activities. No
advice or information, whether oral or written, obtained by you from the authors shall create any warranty
for the software.
Copyright on Software
The copyrights to the WINDaROLL software belong to J. K. Good (Copyright 2007 by J. K. Good). Your
right to use this software was granted by your purchase of this book. Duplication or distribution of this
software by any means for other than your own use without the permission of J. K. Good will constitute a
violation of the copyright.
Trademark Acknowledgements: Windows and Excel are registered trademarks of Microsoft Corporation.
Macintosh and Mac OS are registered trademarks of Apple Computer Corporation.