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Web Handling & Converting

Blogmaster: Dr. David Roisum

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War Stories in Web Handling

26

The Optimum Component Repair Time

Posted by David Roisum on January 26, 2012
The Optimum Component Repair Time
From the previous post we noted that nearly everyone has an idea of the costs of maintenance.  (We used cover grinding as an example, but the application is much wider than this).  The more frequently you grind the greater the maintenance costs.  If that is the only cost management ha...

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Posted in: Maintenance, Problem Solving, War Stories in Web Handling
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24

The Sawtooth and Excessive MTBS (poor maintenance practice)

Posted by David Roisum on January 24, 2012
The Sawtooth and Excessive MTBS (poor maintenance practice)
The Third Law of Thermodynamics and Murphy’s Law both require that things break down.  When do you get around to fixing them?  Maintenance culture tends to fall into one of two patterns.  The first is to fix it when it has to be fixed, i.e., the machine will no longer run saleab...

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Posted in: Maintenance, Problem Solving, Rollers, War Stories in Web Handling, Web Manufacturing
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03

Reasonable, But Wrong

Posted by David Roisum on January 3, 2012
Plants have been a lifelong passion; I have grown (and killed) more than 1,000 species.  I would read, study and try best-practices for many areas of horticulture.  For example, the practice of putting drainage gravel at the bottom of containers/pots was taught by nearly every source for m...

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Posted in: Problem Solving, Spreading, War Stories in Web Handling, Winding
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22

Machine Builder Competence II

Posted by David Roisum on December 22, 2011
How to tell at a glance if your machine builder doesn’t know what they are doing: Lack of calibrated load cell readouts Lack of calibrated nip readouts Tension not steady
Posted in: Design, Nips, People, Tension/Drive Control, War Stories in Web Handling
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20

Machine Builder Competence I

Posted by David Roisum on December 20, 2011
Three simple (but surprisingly effective) ways to know whether your machine builder is competent: Fewest idler rollers Fewest idler roller diameters Fewest idler roller surface types
Posted in: Design, People, Rollers, War Stories in Web Handling
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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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13

The First Roller

Posted by David Roisum on December 13, 2011
Your supplier has provided you with a pretty crappy wound roll.  Captured inside the roll for weeks, the web is just waiting to misbehave.  Let it loose and it will misbehave at the first opportunity; the first roller.  However, if you tame the web at that first roller; it might make ...

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Posted in: Design, Spreading, War Stories in Web Handling, Winding, Wrinkling & Flatness
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29

(Over) Specifying Roll Diameter and Length Simultaneously

Posted by David Roisum on November 29, 2011
I am winding a fluffy product with final specifications on Outside Diameter and Mass. The basis weight and caliper (thickness) ranges are quite wide compared to the final product desired OD and mass. The density (basis weight/thickness) of the media definitely can change within the supply roll of me...

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Posted in: Design, Materials, War Stories in Web Handling, Winding
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22

Baggy Web Conversation

Posted by David Roisum on November 22, 2011
The following is historical fiction.  One where certain essential details are accurate, but the ‘conversation’ has been rewritten to protect the guilty. Dear Dr. Roisum, I was your student in a Converting School back in 20__. We now have a difficult web-handling problem caused ...

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Posted in: Materials, Measurement, Problem Solving, Rollers, Spreading, War Stories in Web Handling, Winding, Wrinkling & Flatness
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06

Baggy Web Survival Strategy

Posted by David Roisum on September 6, 2011
The first time you get baggy material, send the roll back to the supplier. What will they do? They will pay the claim. What will they not do? Fix the problem. The second time you get baggy material, try to find some measure of bagginess and a threshold of pain. Candidates include roll hardness...

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Posted in: (Other) Converting, Problem Solving, War Stories in Web Handling, Web Manufacturing, 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.