Abstract:
Many paper, film, and foil webs are prone to buckling and wrinkling during handling from even slight machine imperfections, such as roller misalignment, deflection, and diameter variations, especially as products substrates are thinner, wider, or stiffer.
This workshop will present the process knowledge needed to eliminate buckling defects in spans between rollers (troughing) or on rollers (wrinkling). Wrinkling and troughing will be eliminated by root cause analysis and by strategic application of special anti-wrinkle or spreader rollers.
Unlike any other option in web handling education, the AIMCAL series of web handling "workshops" are one-of-a-kind training that combines classroom seminars with on-machine demonstrations. Who will benefit from this workshop?
This workshop is directed towards technical employees of any level with a need to understand the fundamentals of wrinkling and spreading. Though the seminar will include some engineering theory and equations, the workshop?s goal is to show how theory and experiment lead to practical solutions to common problems. Wrinkling / Spreading / Traction Seminar Outline
The workshop will aim for a 50-50 split between seminar and lab demonstration time. Seminar topics will include all the background needed to understand the lab demonstrations and more, including: - Definitions - traction, troughing, spreading, wrinkling, taxonomy, etc.
- Web properties influencing troughing and wrinkling
- Machine factors influencing troughing and wrinkling
- Factors influencing traction and relationships to troughing and wrinkling
- Web spreading devices ? theory and practice
- Traction, wrinkling, spreading measurement methods
- Wrinkling elimination action plan
Wrinkling / Spreading / Traction Demonstrations
Lab #1 - Learn The Sign Language of Wrinkles.
Characterize buckling in web spans (troughing) by direct observation or magnified with the "zebra-light." Learn how troughs change with tension, web thickness, and root cause.
Lab #2 - Creating Shear Wrinkles From Misaligned Rollers.
This is the classic experiment for defining a web's wrinkle sensitivity. What misalignment or roller diameter variations will create a wrinkled, creased web? The lab will also show how wrinkle sensitivity changes in web thickness, web width, web modulus, tension, span length, wrap angle, and web-roller coefficient traction.
Lab #3 - Full Speed Measurement of Web-Roller Coefficient of Traction.
See how loss of traction is measured as speeds increase and tension drop and what roller surfaces do the best job of preventing lubrication.
Lab #4 - Spreader and Anti-Wrinkle Roller Comparison of Effectiveness
Two classic experiments will be performed at full production widths (60-in) measuring both anti-wrinkle and spreading performance of the most widely used "special" rollers, including 1) bowed-axis roller, 2) flexible biased-groove rubber roller, 3) expanding surface roller, 4) machined and taped concave rollers, and 5) spiral ridged chevron roller.
Lab #5 - Bowed and Concave Roller Optimization
Learn how to best apply these two popular and effective anti-wrinkle rollers. See how bow roller depth, wrap angle, traction, and span lengths improve or degrade their effectiveness. See how concave roller profile and surface must be matched to the web strain and traction conditions. For more information, click here. |
