As published in Converting Quarterly on Feb 1, 2015, by: E.J. (Ted) Lightfoot, Ph.D., and P.R. (Randy) Schunk, Ph.D.
Abstract
This article highlights ways in which advanced scientific tools can bring practical value to the coating industry and introduces a series of vignettes designed to inspire people working in traditional coating markets to look at new ways of improving and optimizing their current capabilities and to inspire others to move into high value in-use growth markets.
Introduction
The purpose of this article is to introduce an upcoming series of vignettes in Converting Quarterly on the scientific study of coating and drying, written by contributing members of the International Society for Coating Science and Technology (ISCST). Although the process of continuous web coating dates back well over a century, and the engineering science of coating dates back nearly a century (the pioneering work of Landau and Levich [1] is often cited as the origin of modern coating science), interest in coating science has blossomed over the past 40 years. This period of rapid growth is associated with a series of symposia dedicated to scientific understanding of the coating process – as distinct from coating formulations – that started under the auspices of Area 1k of the American Institute of Chemical Engineers. The AIChE symposia on the Mechanics of Thin Film coatings evolved into the International Coating Science and Technology Symposium, sponsored by the ISCST; however, the European Coating Symposium, the Japanese Coating Symposium and the Asian Coating Workshop share this heritage. It is hard to define what differentiates these scientific symposia from other technical meetings on coating, such as the AIMCAL Web Coating & Handling Conference, but anyone who has attended both has felt a difference. The purpose of this series of articles is to give readers of Converting Quarterly a feel for what science can do for industry.
Who uses coating science?
One obvious difference between an ISCST symposium and an AIMCAL technical conference is that the former features predominantly academic speakers. AIMCAL is an industrial association, and most of the presentations at technical meetings are given by technical staff (or management) from industry. Science and technology progresses where it can, industry focuses on what it needs. In some areas, scientific advancements have far outstripped the (perceived) need; in other areas, science has provided little practical help. But those from industry who frequent the ISCST meeting (and the other related symposia) generally find great value in the science. Research topics in coating science conveyed through ISCST conferences over the decades span a broad range. However, the majority of contributions fit into the categories given in Table 1. Anti-trust regulations limit public disclosure of process economics; thus, corporations are generally reluctant to report economic impact of coating science. However, some record of the impact has been evident in open and conference literature. For example, the demise of the photographic industry occurred in inverse order of the commitment to coating science. Invalidated boasting of line-speed increases through numerical optimization generally starts at around 50% and ranges up to doubling the throughput of a given line multiple times. In other cases, the goal has been the elimination of defects and reduction in defect frequency by several orders of magnitude that would not be uncommon. This series of articles will give concrete examples of how scientific analysis of some aspects of coating can be
extraordinarily profitable. Nonetheless, industrial participation in “scientific” symposia represents a small fraction of the industry at large. Thus, it appears the primary limit on the impact of coating science on industry is one of market penetration.
Why has industry been slow to embrace coating science?
The limited penetration of coating science into industry can be rationalized as a natural consequence of volume. Products expected to have sales of a million dollars a year can support a certain investment in research and development. Those expected to sell in the tens of millions of dollars can afford a higher level of technology. Those expected to sell in the hundreds of millions generally benefit from yet another level. But that argument does not explain the success of high-tech startups that engage in scientific symposia or the large companies that choose not to engage in the coating-science community. There are other factors that influence the choice of pursuing coating science. First, science tends to move slowly (by industrial standards). But much of what constitutes coating science is not new – i.e.: mathematical modeling of the coating process has been used effectively for almost three decades. Growth industries tend to have shorter time horizons than mature industries and that may limit the ability of growth industries to employ some scientific means. However, more and more new products depend on high technology – i.e.: controlling complex microstructure – to survive on the market. These technologies may embrace coating science from the start. However, as “technology-push” companies they also have to cross what has been called a “valley of death” before they become profitable. Industry is also known to have a cultural stratification in how corporations respond to discontinuous innovation – innovation that changes how one does business. At the coarsest level, corporations can be divided into an “early market” and a “late market” that are separated by a “chasm [2]”. The “early market” focuses on the advantages of the new way of doing business, while the “later” or “mainstream” market shares an unwillingness to change how they do work until they can integrate this change into a comprehensive business practice. The distinction between continuous and discontinuous change can be appreciated best by example. A new analytical device – i.e.: a nano-indenter or an atomic force microscope – can be run by the same analytical group that serves the business today. That would be a continuous change. On the other hand, the use of computer modeling to optimize the coating process is a fundamentally different way to work than running statistically designed experiments on a coater. Modeling typically requires dedicated resources with more specialized training and skill sets than those of the usual engineers who support a coating machine. That would be a discontinuous change. Since statistical methods remain the flagship approach to managing the fitness for use constraints [3] that are the hallmark of the coating industry, the mainstream of the coating industry has not adopted modeling as a core technology.
Why talk about coating science now?
If engineering science technologies, like modeling and simulation, represent a cultural mismatch with the mainstream of the coating industry, why dedicate a series of articles in Converting Quarterly to them? Because the world has changed in two key ways. First, the barriers to adopting these techniques are shrinking. Second, many of the growth opportunities for coating lend themselves better to a combination of scientific and empirical investigation than the traditionally empirical (Edisonian) approach. In the past, large coating companies maintained specialized laboratories and modeling groups and even identified “coating science” as a core capability. However, very few of these companies continue today with the coating-science competency. The majority of the science that finds its way into industrial practice today comes through academic-industrial partnerships, engineering research centers or the national laboratory system. As a result, it is no longer necessary to dedicate internal resources, develop the tools in-house or wait years for results – if the problem you want to understand has been addressed before. Although many traditional techniques and markets for coating remain strong, much of the projected growth in coating is expected to come from areas where coating science has had its greatest success. Pre-metered methods (both single and multilayered) are currently the fastest growing coating methods [4] and these are the methods where mathematical modeling has been most successful. At least one hardware vendor has added finite element modeling of the coating process to their capabilities [5].
High-tech applications such as microelectronics, photonics or nano-structured coatings and nano-films require a higher degree of sophistication in processing and metrology than most traditional coating markets. Mass-production of nanostructured materials is most accessible through layer-by-layer thin-film coating, embossing and imprinting processes. In all cases, each layer begins as a liquid coating of a material (dispersion, polymer, etc.) with a specific functional purpose. After or during solidification, they can be structured in all directions at the nanoscale through fundamental chemical and mechanical means. Through such an approach, stacks can be tuned for virtually any purpose, including optical, chemical sensing, circuitry, barriers for voltage/electrical standoff and even decorative. It is projected that these levels should reach those of the traditional industries when such operations can be perfected in a cost-effective and environmentally friendly way. Based on National Science Foundation (NSF) estimates, by the year 2015 nanotechnology markets will represent $440 billion per year in chemicals and materials, $70 billion per year in defense and aerospace, $300 billion per year in electronics and computing and $180 billion per year in medicine and healthcare. The total marker for nanotechenabled products and services could reach a staggering $1 trillion. A good portion – greater than 50% – will involve nano-structured coatings.
Conclusion
The “coating science” community fosters collaboration in applying science to advance coating technology. The articles in this series will give examples of how such collaboration can improve coating processes and product performance. Our hope is that these articles will inspire some to look at optimizing their processes and others to move into high-value growth markets.
References
1. L. Landau and V. G. Levich, Acta Phys-Chim USSR 17 42 (1942)
2. Geoffrey A. Moore, Crossing the Chasm: marketing and selling hightech products to mainstream customers, Rev. Ed. New York: Harper Collins (2002)
3. For a discussion of the degree of complexity faced by industry, see Tim Oberle, Processing Techniques for Engineering High Performance Materials, CRC Press (2013)
4. Edward D. Cohen, Coating Method Trends, Converting Quarterly Web Coating Blog post April 3, 2012
5. D. Eggerath, “Viscosity dependency on liquid curtain stability,” 2013 European Coating Symposium Mons, Belgium, Sept 11, 2013
E.J. (Ted) Lightfoot, Ph.D., holds a B.S.E. from Princeton University and an M.S. and Ph.D. from the University of Illinois at Urbana-Champaign. He was an industrial fellow at the University of Minnesota Center for Interfacial Engineering. Ted is a founding director and former president of the International Society for Coating Science and Technology and he currently chairs the Scientific Advisory Committee of the ISCST. He has been employed in various roles relating to the coating, drying, laminating and extrusion industries by E.I. du Pont de Nemours & Co. for over 30 years. Ted is currently assigned as a principal investigator in DuPont’s Photovoltaic FluoroMaterials business. He can be reached at 716-879-1711, fax: 716-879-4568, email: e.j.lightfoot@dupont.com
The original article can be found online here.