Mark Miller helps you identify the right material selection for tooling that will carry fluid to your substrate.Read more
Product and Technology of the Year Awards praise Hazen for Titleist golf ball sleeves and cartons and SAM N.A. for slot die with internal …Read more
Web handling expert Tim Walker offers three options for this machine direction folding process.Read more
Marketing expert Mark Lusky offers 3 tips to help you rev up your reputation and credibility in the marketplaceRead more
News | New Products
Frito-Lay floor stand honored as Temporary Display of the Year and Most Creative Temporary Display
Demand for space is said to be strong for the 2016 trade fair for plastics and rubber, with 3,000 exhibitors expected to fill the halls
The 3600 Series undergoes an engine upgrade to run at higher speeds, reportedly with no loss in print quality
The Solution Coating Technical Center will offer customer trials and demos, toll coating, and R&D for the coating industry
The Tau 330 UV inkjet digital label press is said to provide up to 2 hours of uninterrupted printing, fewer changeovers, and less downtime
The DSS Compact Coex die is said to provide many benefits with less height and weight
The SPI Automatic Film Splicer performs non-stop film changes in food and beverage packaging operations
Directories | Reports
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- October 08, 2013
A simple question with a not so simple answer. Let's start by narrowing down the culprits.
If the web moves off centerline, there are a limited number of reasons this happens.
1. Roller misalignment
2. Roller diameter variations
3. Web bagginess
4. Nip pressure variations
5. External forces
Mechanism #1, roller misalignment and the parallel entry rule (see in my next blog!) are extremely important concepts to understanding webs and web handling. The parallel entry rule describes what the ideal web will do between misaligned roller if there is sufficient traction to bend the web. Without sufficient traction, the web behavior on misaligned roller is less predictable.
Mechanisms #2 through #4 are all dependent on the parallel entry rule. Therefore, which way a diameter variation, baggy web, and uneven nip will shift a web is also a function of traction.
Mechanism #5 (or external forces) includes the sundry possible interactions of the web to elements of the outside world, whether solid, liquid, or gas, including interaction with people, equipment, attached parts, air flow, or coatings.
But what's this Parallel Entry Rule? Nothing but the most important rule in web handling, that's all! Tune in for more with my next blog post.