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
Companies excelling in technical innovation, print excellence, and sustainability as well as industry leaders are among those honored by FTA
The 18th edition of the show is said to be the gateway to 380 million consumers in the East African Region
Shingle stream method uses company’s Tornado technology to enable automated variable overlap shingling for variable length sheeting and stacking
The 9th Annual IMDA Awards Competition will recognize IML packaging, IMD durable products, and labels in multiple categories
The companies will develop inspection solutions for sectors including labeling and packaging and also will co-develop print quality assurance solutions
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
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 18, 2013
If you'd like to hear from Mark Miller's own lips rather than read his Coating Matters blog post titled, "Visualization for Improved Coating Performance," click on his podcast below:
On many coating projects that I have been involved in, the coating defect that the team was trying to eliminate was apparent on the web, but where the defect originated was not known. This leads the process and product team down different paths of experimentation and analysis to understand the root cause of the defect. Sometimes this approach takes a couple hours, and sometimes it takes a couple months. Either way, time could be reduced with a better theoretical understanding of the flow dynamics.
So what techniques can be used to better understand fluid flow and defect analysis? Flow simulation software and lab-scale visualization techniques can provide great insight into the world of fluid dynamics. I have used these techniques in the past to reduce troubleshooting time and use of raw materials, reduce defects, and improve equipment design. We can see what the final product looks like off the winder. We can watch the fluid being coated on the web and after the curing step. What we cannot see is what is going on at the interface of the fluid and the substrate, or how the fluid is reacting as it travels from the tank to the pump to the coating head.
One technique that has been successfully used to see these difficult regions of the coating system is photo-visualization. Photo-visualization of a coating process requires high speed cameras, proper lighting, and light manipulation through mirrors and optics to develop an image that captures the fluid and defect of interest.
As an example, I have seen a fluid be coated against a quartz backing roll, where the camera is located inside the roll and captures an image of the fluid as it exits a slot die. Even without this unique design, placing optics where people can stand in a typical coating arrangement can bring better understanding of the flow dynamics involved at the fluid substrate interface. This perspective can answer questions that cannot be answered with internal flow computer programs or the naked eye.
Working back from what we can see to what requires a more complex arrangement of light management takes some time, but in the end, may be the only way to truly know what is going on at the coating head/substrate interface. Working back from this point into the coating head requires theoretical visualization.
Computer models of the manifold geometry, materials of construction, rheological information, and proper fluid models are critical to prediction of the flow behavior inside a coating head.
Taking the information obtained through designed experiments that systematically break down the process and product variables, combining them with visualization techniques, and closing the loop with theoretical internal flow data can provide the manufacturing engineer with the complete picture of fluid interactions. Interactions with piping, distribution, coating, surface reaction, and drying all lead to potential defects. Breaking each unit operation down to see what is happening leads to solutions with data instead of inference.
If you are interested in discussing this concept further, contact Mark D. Miller, founder and CEO of Coating Tech Service, LLC (www.coatingtechservce.com) at firstname.lastname@example.org or 612-605-6019.