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
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
Attendees at the Spring meeting will have the opportunity to tour International PaperBox and learn about the company’s best practices
The PrimaPak package for Kar’s Nuts Second Nature Wholesome Medley is a silver winner in FPA competition
The association’s agenda includes a series of conferences and meetings to provide education and recognition to members of the narrow web industry
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 email@example.com or 612-605-6019.