Here are 3 web handling rules Tim Walker keeps forgetting to tell you.Read more
Music City plays host to converters attending the Flexographic Technical Assn.'s annual conference and exhibition.Read more
When looking for process, product, and profit improvements for your PSA tapes and labels, consider going back to the drawing board.Read more
Folding carton and corrugated converters will find equipment displays and educational opportunities in die-cutting, foil stamping, embossing, and more.Read more
News | New Products
The Graphium hybrid digital inkjet press has many new features, and company also announces new label production workflow
The XN Cantilever Load Cell is loaded with features said to make it a cost-effective drop-in component for tension measuring
Company seeks patent for its UltraPerf Rule for corrugated board, said to reduce corrugated board wrapping and improve dimensional accuracy control
COMET will expand its electron beam business with the purchase, adding PCT’s BroadBeam line of EB solutions
The event, again co-locating with CPP EXPO, features a floor area for unique print applications and a pavilion focusing on print of the future
Company will present the Varyflex V2 offset press and the iFLEX label press at an event held in conjunction with Converflex
Indonesian workshop with strategic partner Fuji Yusoki Kogyo showed benefits of fully automated processes, even where low wage structure is in place
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.