At well over 1 million sq ft and growing, the triennial plastics showcase will have operating equipment at 400+ booths.Read more
PFFC's "On Print" columnist Dene Taylor will present educational session on packaging.Read more
The fundamentals of air entrainment, entrapment, and rheology are critical to product success.Read more
The high barrier performance of EVOH, even after abuse, has allowed for conversion from foil and metallized film laminations to co-extruded barrier films.Read more
News | New Products
Guardian chucks offer new handwheel, journal seat, and housing design
New version of the Sanilox system can be seen on company’s redesigned website
Patent-pending films developed by Pregis for inflatable cushioning applications
Thermoplastic elastomers are said to protect the freshness, quality, and safety of food and beverages
The company has had a busy and productive decade as a supplier of protective packaging solutions
An impressive array of speakers also will address economic trends, building winning organizational cultures, and more
SpearRC developed to offer PET bottle the benefits of pressure-sensitive labels
Directories | Reports
PFFC brings you exclusive White Papers from our online sponsors.
Visit Kelly on Static from Static control expert Dr. Kelly Robinson, president of Electrostatic Answers; Kelly has 27+ years of experience in problem-solving and consulting.
Visit Tim's Web Lines to handle and wind your paper, film, foil, and similar products. Take advantage of Tim’s 25+ years just like over 100 converters have.
Visit Mark's Coating Matters from fluid coating expert Mark D. Miller; Process improvement and project management for precision roll-to-roll coating applications.
Visit Marketing Mojo for dynamic marketing insights from Stephanie Millman that inspire new ideas on how to stay on top of your customer’s mind.
Visit Yo’s Yarns to share the thoughts, impressions, experiences, and news that impact the converting industry. . . or anything else that happens to be on her mind!
Visit Tom's Poly Ploys, where Tom will be writing on various topics that the typical polymer processor would encounter on the job.
- 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.