Industry-First Process and Adhesive Development Reduces CO2 Emissions in Film Packaging Production by Approximately 61%

Under a NEDO-subsidized project, Mitsui Chemicals, Inc. and Toray Industries, Inc. have jointly developed an industry-first process that performs solvent-free lamination and electron beam (EB) irradiation inline, along with the corresponding adhesive for the lamination process. By integrating Mitsui Chemicals' urethane adhesive technology with Toray's EB-curable flexo/offset printing technology, the companies successfully improved the adhesive performance of EB-curable adhesives significantly. The development of this inline lamination and EB irradiation process has achieved a reduction of 3.09 million kWh in annual power consumption and 1,290 tons in CO2 emissions, representing a reduction of approximately 61% in the lamination process of film packaging production. Moving forward, the companies aim to achieve both environmental compatibility and improved productivity by reducing energy consumption and CO2 emissions across the entire film packaging production process, from printing to lamination. Film packaging is multi-layered through lamination to enhance product protection, barrier properties, heat resistance, and chemical resistance. Leveraging its lightweight, transparency, and ease of processing, it is widely used for food packaging and refill pouches for shampoos and detergents. Furthermore, the shift from glass bottles, cans, and plastic containers to film packaging contributes to resource conservation and food loss reduction. The global market for film packaging was approximately 38 trillion yen in 2022, with an annual growth rate of 3.2%. In domestic film packaging production, the breakdown of CO2 emissions is 52% for the film process, 32% for the ink/printing process, and 16% for the lamination process. Efforts to reduce CO2 emissions are underway in the film and printing processes, such as the use of bio-based raw materials, mono-materialization, and solvent-free processes. On the other hand, the lamination process traditionally uses petroleum-based solvents in adhesives, consuming large amounts of electricity for heat drying after coating and combustion treatment. Furthermore, because the adhesive is not fully cured immediately after lamination, heat treatment (thermal curing for about 5 days) is required to prevent appearance defects. This process increases manufacturing time and power consumption. Therefore, reducing CO2 emissions in the lamination process has been an urgent issue. Against this backdrop, NEDO has been working with Mitsui Chemicals and Toray since fiscal 2023 as part of this project to develop an energy-saving flexible packaging lamination system. In this joint development, the companies adopted a solvent-free EB-curable adhesive instead of solvent-based adhesives and developed a new technology that performs lamination and EB irradiation inline. The current lamination process uses two-component thermosetting adhesives, which require solvent drying after application and heat treatment after bonding, emitting approximately 2,127 tons of CO2 per laminator annually. While using solvent-free adhesives can eliminate solvent drying, it faces challenges such as longer heat treatment times, lower processing speeds, and reduced adhesive performance. In this joint development, by applying EB-curable flexo/offset printing technology to urethane adhesives, the companies significantly improved adhesive performance. By making the lamination and EB irradiation process inline, solvent drying became unnecessary, and it became possible to shorten heat treatment time and lower temperatures. As a result, annual power consumption for the lamination process was reduced by 3.09 million kWh, and CO2 emissions were reduced by 1,290 tons, a reduction of approximately 61%. This new technology solves the issues of curability and processability found in conventional technologies and contributes to VOC-free production as it contains no solvents, making it an industry-first next-generation lamination process. These results provide an effective option for reducing Scope 3 emissions in supply chain emission calculations, as they can significantly reduce CO2 emissions in the lamination process without major changes to packaging specifications. Mitsui Chemicals and Toray will promote this technology combined with EB-curable flexo/offset printing technology to distributors and brand owners, aiming for standardization in food and daily goods film packaging, with the goal of social implementation by 2027.