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Time for Unwinding Upgrade?

Published: September 01, 2009, By By Timothy J. Walker Contributing Editor

How do you know when its time to upgrade from a brake-controlled to a driven unwinding process?

Winding Doesn't Add Up

Published: August 01, 2009, By By Timothy J. Walker Contributing Editor

When things in life are linear, they make sense. Driving two hours usually gets you twice as far as driving one hour. Adding two doughnuts a day to your

Playing the Wrinkle Blame Game

Published: July 01, 2009, By By Timothy J. Walker Contributing Editor
Imagine you are an unwind operator. You unwrap the next roll of input material, splice it into the machine, and hit the run button. Then you see them

Stress & Strain

Published: June 01, 2009, By By Timothy J. Walker, Contributing Editor

A properly tensioned web always will lead to better slitting. Good tensioning is important up to, through, and out of the slitting blades. A poorly tensioned

The Coefficient of Winding Trouble

Published: May 01, 2009, By By Timothy J. Walker Contributing Editor
In winding, the important coefficient of friction (COF) is always about the two surfaces that will come in contact as the entering layer hits the winding

The Great Span Length Debate | Part 2

Published: April 01, 2009, By By Timothy J. Walker Contributing Editor
Last month, we debated roller spacing (a.k.a. web span length) relative to cost, safety, out-of-plane deviations from gravity, bagginess, and misalignment. Let's continue the debate.

The Great Span Length Debate | Part 1

Published: March 01, 2009, By By Timothy J. Walker Contributing Editor
There are at least half a dozen things that come to mind in the great span length debate. Let's review the checklist to figure out what span length is right for you.

How Much Misalignment Is Trouble?

Published: February 01, 2009, By By Timothy J. Walker Contributing Editor
Shear wrinkles are the most common wrinkle mechanism, forming a diagonal crease and appearing to walk across rollers like an inch worm. The way to create

How Much Misalignment Is Trouble?

Published: January 01, 2009, By By Timothy J. Walker Contributing Editor
Most converting equipment suppliers and manufacturers take care to ensure the rollers of their machines are aligned. Designing for good alignment, machining

Who's Driving This Nip?

Published: December 01, 2008, By By Timothy J. Walker Contributing Editor
What is the best way to drive a set of nipped rollers? Two rollers and two drive options (driven or not) lead to four options. To make this discussion

Shifty Answers to Nip-Induced Tracking

Published: November 01, 2008, By By Timothy J. Walker Contributing Editor
Nipping rollers are used in many value-adding processes in web converting roll coating, laminating, embossing, calendering, high-speed winding, and more.

Do You Have a Need for Speed?

Published: October 01, 2008, By By Timothy J. Walker Contributing Editor
Faster, faster, faster. As you reach the designed capacity of your existing process, before buying new equipment, most converters will ask if they simply

A Wealth of Accumulators

Published: September 01, 2008, By By Timothy J. Walker Contributing Editor
A good accumulator should be like money in the bank easy to deposit and readily available to withdraw when you need it. A web accumulator is like a bank,

Winding: What We Know & What We Don't Know

Published: August 01, 2008, By By Timothy J. Walker Contributing Editor
Winding is an amazingly complex process. Our understanding of winding can be broken into three areas: the winding process, winder design, and wound roll

Idler Roller Bearings: Living the Good Long Life?

Published: July 01, 2008, By By Timothy J. Walker Contributing Editor
Most bearings are designed for a hard life, expecting to end up on a drive shaft of a high-speed motor with a heavy load. Some bearings, however, end

Web Lines: The Spin on Idler Roller Testing

Published: June 01, 2008, By By Timothy J. Walker Contributing Editor
It's an election year, so I'd like to join the political pundits and offer some spin of my own, but my spin will be free of political opinions. Instead,

A Recipe for Scratching

Published: May 01, 2008, By By Timothy J. Walker Contributing Editor

This month we're having another session of Do the Opposite. I'm going to tell you how to make great scratches. The solution to stopping scratches is to

Your Guide to the Right Web Guide

Published: April 01, 2008, By By Timothy J. Walker Contributing Editor

Webs are blind they don't know where they are going. With a well-aligned roller, sufficient tension, and good traction, the web has a tendency to track

Buyers & Suppliers: Can We Dance?

Published: March 01, 2008, By By Timothy J. Walker Contributing Editor

Buying equipment is a partnership between the equipment buyers and equipment suppliers. The dance begins when a buyer has a need (and hopefully the money)

Web Lines: Thinking About New Equipment?

Published: February 01, 2008, By By Timothy J. Walker Contributing Editor
A new year often brings new budgets and thoughts about new equipment. If you are lucky enough to be handed a project to buy new converting equipment,

Get a Grip: Driving Your Web

Published: January 01, 2008, By By Timothy J. Walker Contributing Editor

In my October 2007 column, In Search of Tension Isolation, I myth-busted the belief that a high traction driven roller can completely isolate one tension

Differential Winding Limits: Part I

Published: November 01, 2007, By By Timothy J. Walker Contributing Editor
The purpose of differential winding is to apply a desired torque to two or more rolls winding on a single shaft. Differential winding allows multiple rolls to turn at differing speeds, with each roll free to slip at the speed required to compensate for roll-to-roll diameter variations and strand-to-strand length variations.

In Search of Tension Isolation

Published: October 01, 2007, By By Timothy J. Walker Contributing Editor
In web handling, one of the myths told most frequently is that of the independent tension zone, protected from other tension zones by the protective powers of the tension isolation. Like most myths, we want to believe, but alas, scientific reason is the myth buster.

Support Your Rollers

Published: September 01, 2007, By By Timothy J. Walker Contributing Editor
How should a roller be supported or attached to your equipment? To answer this question, let’s review your roller support needs and your options to meet these needs.

Baggy Webs: Part 4 Minimizing

Published: August 01, 2007, By Timothy J. Walker, TJWalker & Assoc. Inc.

What does minimizing a baggy web mean? Two things. First, we would like to minimize the level of bagginess in our webs. Second, we would like to minimize the waste associated with running the inevitable baggy web in our processes. To minimize the creation of baggy webs, we must take on their causes.

Baggy Webs: Part III-Causes

Published: July 01, 2007, By By Timothy J. Walker, TJWalker & Assoc. Inc.
We know baggy webs are a problem and we know we can measure them. What do we do next? First, we need to find a way to fix it in the short term. Second, we can work on a long-term plan to prevent baggy webs from happening.

Under Pressure (A Brighter Look)

Published: June 01, 2007, By By Timothy J. Walker, TJWalker & Assoc. Inc.

Mr. Starcevic taught my 8th grade algebra class and was one of my most memorable teachers. He quizzed us every week, and as he passed out our graded results,

Baggy Webs: Part II Measuring

Published: May 01, 2007, By By Timothy J. Walker TJWalker & Assoc. Inc.

I'm not usually a big fan of management adages, but this is one I often can support: You can't manage what you don't measure. How do you expect a defect

Baggy Webs: Part I Nightmares

Published: April 01, 2007, By By Timothy J. Walker, TJWalker & Assoc. Inc.

This is the first of four columns on baggy webs, starting with understanding the problems they create. To most converters, the ideal web is one that is

Under Pressure (Revisited...and Revised)

Published: March 01, 2007, By By Timothy J. Walker, TJWalker & Assoc. Inc.

If I have any repeating theme to understanding web handling, it is to follow the stresses and strains. In nipped processes, you need to follow the compressive stress (aka pressure).

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