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Web Handling & Converting

Blogmaster: Dr. David Roisum

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Wrinkling & Flatness

03

High edges, narrow layon rollers and other confusion

Posted by David Roisum on May 3, 2012
Q: A colleague of mine recently stated that use of a lay-on or rider roller that is not as wide as the web is 'common practice'. He sees this as a form of 'winding optimization', whereas the word that I would use is more like 'accommodation'.  We are winding a delicate .001" thick film that is ...

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Posted in: Nips, War Stories in Web Handling, Web Manufacturing, Winding, Wrinkling & Flatness
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24

Wrap Angle Rock Around the Clock

Posted by David Roisum on April 24, 2012
Wrap Angle Rock Around the Clock
At uber, ultra, very, big, great risk of over-generalizing and over-simplifying, I would like to offer you some ideas on some application range for wrap angles.  The application ranges include idlers, tendency and driven rollers and include systems that are and are not wrinkle-prone.  Here...

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Posted in: Design, Rollers, Spreading, Wrinkling & Flatness
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22

Wound Roll Wrinkles – Top of the Roll

Posted by David Roisum on March 22, 2012
The top of the wound roll is especially wrinkle prone.  Gage variations build to make wound roll geometries that are orders of magnitude cruder than rollers.  The nip and thus tightness of many surface winders increases thus making tighter wound rolls that are less able to cover up manufac...

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Posted in: Web Manufacturing, Winding, Wrinkling & Flatness
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20

Wound Roll Wrinkles – Bottom of the Roll

Posted by David Roisum on March 20, 2012
The bottom of the wound roll is especially wrinkle prone.  Here, the core has a geometry an order of magnitude cruder than a roller.  Here, the first wraps are likely ugly.  Here, the bending stiffness of a center-wound system is limper than a wet noodle.  Here, we have tension a...

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Posted in: Rollers, Winding, Wrinkling & Flatness
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28

Wishful Thinking - Baggy Webs

Posted by David Roisum on February 28, 2012
A few students are disappointed in the baggy web part of my Wrinkling module of my Web101 course.  What they expected was some ‘web handling tricks’ such as a tension setting or spreader or something that would make bagginess better.  However, by time they get to my class they&...

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Posted in: Materials, Problem Solving, Spreading, Upcoming Events, Wrinkling & Flatness
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15

Wishful Thinking – Tension and Wrinkling

Posted by David Roisum on February 15, 2012
Wishful Thinking – Tension and Wrinkling
Getting stuck in problem solving is epidemic.  We get stuck on wishful thinking, optimism, hope and a host of other ‘positive’ attitudes.  Now, don’t get me wrong, I am not suggesting that these traits are necessarily bad, only that they can be when you get stuck in a rut...

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Posted in: Problem Solving, Tension/Drive Control, Wrinkling & Flatness
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18

Core Shaft Deflection

Posted by David Roisum on January 18, 2012
Is there a “rule of thumb” or guideline for allowable winding shaft deflection for in-line slitting?  I am talking to a converter that wants to in-line slit a heavy extrusion coated product on his turret winder, possibly up to 66” wound roll diameter.  Is it as simple as ...

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Posted in: Design, Nips, Rollers, Winding, Wrinkling & Flatness
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12

Narrow (or is it) Web Handling

Posted by David Roisum on January 12, 2012
I am thinking of signing up for your course.  Does web handling apply to narrow webs? Narrow webs are sometimes defined as less than 1 meter wide.  Most web-handling directly applies to narrow webs.  A few exceptions occur on the narrowest of the narrow, i.e., ribbon-like materials.&...

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Posted in: Design, Nips, Slitting, Spreading, Tension/Drive Control, Winding, Wrinkling & Flatness
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05

How Soft is Soft?

Posted by David Roisum on January 5, 2012
How soft must a rubber-covered roller be in order to feel soft (i.e. to be effective) to improve winding?  This question must be posed and answered correctly for each situation because rubber covers are more expensive than plain steel AND will increase the risk of wrinkling due to both wear and...

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Posted in: Rollers, Winding, Wrinkling & Flatness
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15

The Last Roller

Posted by David Roisum on December 15, 2011
The last roller is special.  It is right before the winding roll.  Because the winding roll has such crappy geometry, such as having diametral profile variations two orders of magnitude greater than a roller, it is just waiting to misbehave.  So, how to we give our web the best chance...

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Posted in: Design, Rollers, War Stories in Web Handling, Winding, Wrinkling & Flatness
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Blogmaster

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Dr. David Roisum

Dr. Roisum is a well-known authority in the area of web handling and converting. He has authored seven books, including Winding, Rollers and Web-Handling and has coauthored or edited several others. He was a technical editor for Converting Magazine with a monthly column entitled "Web Works." An accomplished professional speaker and instructor, Roisum has been praised for his skill at translating highly technical information into a common sense practical reference. Dave has been honored by TAPPI with their Finishing & Converting Division Award, Thomas W. Busch Prize and Finest Faculty awards and is a TAPPI Fellow. Dave received his Ph.D. from the Web Handling Research Center where he later became an Industrial Advisory Board member.

Dave has worked for the Beloit Corporation as a designer of winding machinery and later as a manager of research, and for Kimberly-Clark as a converting expert serving all business units. He is now a principal of Finishing Technologies Inc., providing consulting services to more than 300 clients who convert or manufacture: paper, film, foil, nonwovens, textiles and many other materials. He has accumulated much practical experience working in nearly 1,000 plants over the course of more than three decades.