- May 01, 2013, Mark Miller
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What does the future hold? If we could gaze into the crystal ball of fluid coating and know what the expectations for liquid coating onto substrates was going to be in years to come, what would the equipment and material scientists be working on today? Luckily, the world of roll-to-roll coating, curing and converting tends to follow an evolutionary path. Because of this stepwise development, predictions of disruptive technology play less into the converting industry.
So then we should be looking for trends instead of spikes. The trends tend to be focused on product and process needs for customer and engineering focus. Expectations are increasing for coated products as diverse as optical film and battery technology. The product performance is going up, while the price is being driven lower. With increased speeds, thinner coatings, and increased functional performance, awareness of coating techniques and technologies is required to be competitive. To gain a competitive advantage, chemists are packing more capability into every fluid molecule. As these fluids become more powerful, the costs of the materials go up. With increasing material cost, process engineers are being asked to reduce waste. The key to waste reduction is to look at pre-metered coating techniques that distribute the fluids evenly across a substrate with minimal waste.
Closed (versus open) liquid delivery and coating systems allow for pre-metered coatings, and also reduce the possibility for contamination. Medical products, optical screens, and other clean room products are driving coating systems to be uniform, bubble-free, and homogeneous. Controlling the coating to the size and shape required in the final product has led to many developments in discrete coating onto continuous webs. This requirement has developed into many mechanical, electrical, and hydraulic responses to the question of “how do you coat a rectangle onto a moving substrate?” The coating process engineers have made progress, but the equipment investment goes beyond the simple static coating station. So while there is more initial investment in equipment that has more capability, the reduction in waste and the more consistent and continuous coating recoups savings quickly.
All the sophistication in coating capability is not limited to the coating head and fluid delivery system however. Scientific principles and data collection are leading the charge to understand operating windows for products and increase the use of statistical process control (SPC) for product release. The use of data logging and experimental design to understand the limits of materials and equipment have provided a depth to the fluid coating world not previously mined. Combining SPC and operator knowledge can lead major product quality and process efficiency improvement projects.
SPC can lead the charge in reducing defects and costs associated with coating. From both the fluid and substrate perspective, a coating operation window can be developed around the rheology, viscosity, surface energy, line speed, and pressure profiles present within a specific equipment design. Simulation software can interpolate the data provided from an existing system to develop improvement projects to decrease operational costs. Coating defect libraries provide operators and process engineers with the insight required to attack a coating problem with a control plan.
Currently outside the spectrum of statistical and simulation operations is the developing world of reactive material chemistry in fluid coating technology. To gain an edge in developing fluids not available in one set chemical molecule, industrial chemists are pushing the coating world to understand and control reactive chemistries within closed systems. With defined residence times and exponential curing systems, the stepwise progression in the world of reactive chemistries is challenging. Chemists and process engineers have to collaborate more than ever, as the interactions between fluid formulation, process capabilities, and product performance collide in the new world of coated products.
Overall, the future of fluid coating technology is evolving towards a world of faster, thinner, and higher quality coatings that reduce energy use and yield better financial returns. While prognosticating the future is not required to successfully develop new fluid coated products, understanding the trends will lead to better decision making on the material and equipment fronts of your business.
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.