First developed for the photographic film and food industries, curtain coating – also known as contour coating – is extensively used throughout the paperboard, specialty paper, adhesives, battery, and fuel cell industries. It is quickly becoming a preferred coating method where uniform coating coverage and thickness are essential, allowing producers to optimize the cost of expensive coating materials and optimize performance.
Knowing curtain coaters play a crucial and growing role in these applications, Trinseo recently installed a 5-layer slide die curtain coater at our Midland, MI (USA) pilot coater facility. This tool complements our laboratory curtain coater capability in Rheinmünster, Germany, allowing us to collaborate with customers as we jointly develop products that meet new quality, sustainability, and innovation goals across many applications and industries.
Curtain coating can be used to optimize coating performance and total material costs. This technique produces a uniform application coating weight in one coating application step. Compared to traditional coated paper and paperboard coating techniques, less coating is required to fill the system (no return loop), and coating is rarely dumped during web breaks and coating transitions, reducing waste.
More importantly, this process enables a multilayer approach to coating design, whereby multiple layers of different coatings can be applied to a substrate to capitalize on each layer’s respective performance benefits. Research by Trinseo and others on multifunctional barrier coating systems using curtain coaters has demonstrated that curtain-coated substrates can offer sufficient barrier properties against multiple media simultaneously, such as oil and grease, water, moisture vapor, and oxygen.
Packaging Design and Sustainability
Looking forward, curtain coaters coupled with unique coating materials like those offered by Trinseo could find utility to help the paper and board industry meet its brand owners’ goals for more sustainable packaging. Curtain-coated pulp-based substrates can achieve similar barrier performance to some laminated plastic packaging structures. Additionally, most coatings applied to the substrate during curtain coating can be recycled in traditional paper recycling processes. Designing new curtain-coated packaging materials to be recyclable would create a sustainability advantage.
Brand owners are moving away from single-use, non-recyclable plastics towards recyclable and innovative coated paper and paperboard packaging solutions.
Collaborating with Customers
Our Midland pilot coating facility is equipped and staffed to promote a collaborative, low-risk testing environment. Customers work with our technical experts to design trial programs to test the best combination of new products utilizing Trinseo’s technology expertise and know-how. This asset is complemented by our high-speed lab curtain coater at our Rheinmünster application development center.
Customers can trial materials with our curtain coater to see how combinations of products perform under dynamic simulation under the appropriate drying, curing, and web handling conditions – eliminating the cost and risk of running full production trials on their larger machines.
Curtain coating continues to demonstrate performance benefits for many industries and can enable companies to design new and innovative products and support sustainable product development. Trinseo is proud to offer this capability to our valued customers and will continue to offer capabilities that enhance a collaborative atmosphere for product development.