Trinseo’s Don Ventresca, Senior Technical Service and Development Specialist, and Gregory Welsch, Global Innovation Leader, Paper & Board, co-authored a paper recently published in Tappi Journal, entitled “Multifunctional Barrier Coating Systems Created by Multilayer Curtain Coating.”
The paper illustrates the unique combinations of barrier chemistries that can enable multifunctional barrier performance through the high utility of multilayer curtain coating technology, thus enabling paper-based materials to compete against plastic-based films.
Abstract: Functional coatings are applied to paper and paperboard substrates to provide resistance, or a barrier, against media such as oil and grease (OGR), water, water vapor as measured by moisture vapor transmission rate (MVTR), and oxygen, for applications such as food packaging, food service, and other non-food packaging. Typical functional barrier coatings can be created by applying a solid coating or extruded film, a solvent based-coating, or a water-based coating to the paper substrate using various means of coating applicators.
This paper focuses on water-based barrier coatings (WBBC) for OGR, water, MVTR, and oxygen barriers. The main goal was to create coated systems that can achieve more than one barrier property using multilayer curtain coating (MLCC). Curtain coating has emerged as the premier low-impact application method for coated paper and paperboard.
This paper provides examples using MLCC to create coating structures that provide multiple barrier properties in a single coating step. Barrier polymer systems studied include styrene butadiene, styrene acrylate, vinyl acrylic, and natural materials, as well as proprietary additives where required to give desired performance. The paper also shows how the specific coating layers can be optimized to produce the desired property profile, without concern for blocking, as the addition of a non-blocking top layer can be applied in the MLCC structure as well. Experiments on base sheet types also shows the importance of applying the multilayer structure on a pre-coated surface in order to improve coating thickness consistency and potentially allow for the reduction of more expensive layer components.
Application: For mills contemplating a new coater, this research shows that an MLCC coater is cost-effective and technically advantageous for production of barrier coated paper and paperboard grades. Also, for companies that already have MLCC coaters, this research shows that WBBC technology is currently available for production of multiple-layered barrier paper and paperboard grades.