Lubrizol releases white paper on physical foaming of TPU

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Amid the ongoing growth of running as a global sport and the increasing integration of professional training with everyday running, the midsole in running shoes has evolved from a component with a single function to a key system that influences performance, manufacturing efficiency, and sustainability goals. In line with this structural change, Lubrizol, a global leader in specialty chemicals, officially released today the white paper titled \"Empowering Performance for Faster Advancement: A New Ecosystem for TPU Physical Foaming in Running Shoes,\" which provides a comprehensive overview of the technical principles, manufacturing processes, and industrial collaboration framework related to TPU (thermoplastic polyurethane) physical foaming in the soles of next-generation running shoes. As the inventor of TPU technology, Lubrizol has conducted in-depth analysis, based on global advancements in material innovation and industrial practices, of the structural challenges related to the performance, manufacturing, and environmental aspects of running shoe midsoles. It has also demonstrated how physical foaming of TPU can overcome the limitations of chemical foaming of EVA, offering the industry a path toward achieving both improved performance and high-quality, large-scale production. The white paper further states that the upgrading of mid-sole technology requires close collaboration among materials, processes, and equipment, and it outlines a \"dual-track\" approach involving foam formation using autoclave molds and supercritical injection molding, each focusing respectively on achieving higher performance limits as well as improving manufacturing efficiency and automation levels, thereby supporting future multi-layered, global product systems. Ms. Zhang Lu, Global Vice President at Lubrizol, said: “The midsoles in running shoes are undergoing a profound structural transformation; the focus of competition is no longer limited to individual performance metrics, but is gradually shifting towards a comprehensive evaluation of manufacturing systems, consistency of experience, and industrial collaboration capabilities.” Through this white paper, we aim to transform Lubrizol’s long-term technical expertise in TPU physical foaming into a reference framework that will assist the industry in contemplating future manufacturing methods and collaboration models. We believe that the next phase of advancement in the running shoe midsole industry will depend on whether it is possible to establish an innovation ecosystem that is experience-oriented, efficiency-based, and centered on collaboration. This is not merely a technological evolution, but also a systematic upgrade of the entire industry’s value system. ”From the consumer perspective, global runners’ expectations regarding running shoes are continuously rising. They are no longer satisfied with merely temporary lightweight properties or rebound performance; instead, they place greater emphasis on long-term durability, consistent performance, and the stable quality of the products across different batches and markets. Under this trend, the white paper states that physical foaming of TPU is gradually becoming an important technical option to support global production systems and multi-regional manufacturing replication. Justin Park, Global Footwear Materials Director at Lubrizol, said: “Physical foaming of TPU delivers a fundamental improvement in three aspects: performance, wearing experience, and environmental performance.” It not only provides more efficient rebound feedback and longer-lasting comfort in running shoe midsoles, but also enables the industry to achieve more stable, efficient, and reproducible manufacturing processes. From the perspective of industrial development, the large-scale application of physical foaming technology has become an irreversible industry trend. ” The key insights from the white paper released this time are as follows: Ÿ Physical foaming is essential, with parallel advancements in two different technologies: Given that traditional EVA chemical foaming struggles to meet the requirements regarding performance, efficiency, and environmental sustainability at the same time, physical foaming, thanks to its technical advantages, has become an important direction for industry transformation. The two main technical approaches – autoclave mold foaming and supercritical injection molding foaming – each have their own strengths and complement one another, working together to drive the advancement of the midsole industry in running shoes. · TPU is an ideal material base for physical foaming technology: it enables a balance between structural stability and lightweight properties during the physical foaming process. In particular, engineered aliphatic TPU exhibits balanced and excellent performance in terms of rebound efficiency, compression deformation control, and aging resistance, thereby enabling the midsoles of running shoes to provide a reliable and consistent wearing experience across various usage cycles and manufacturing conditions. · Triple synergy creates pathways for high-quality, large-scale production, and the industrial ecosystem is being reshaped: The white paper emphasizes that the key to achieving high quality on a large scale lies in establishing a coordinated system that integrates \"materials, processes, and equipment\". Materials determine the upper limit of performance, processes enable the conversion of value, and equipment ensures stable replication. At the same time, the running shoe industry is shifting from linear supply chains to value platforms based on collaborative creation, using synergistic innovation to enhance the user experience, with the ultimate goal of returning to the consumer experience as the core value. In the field of physical foaming, Lubrizol has long been committed to innovation in materials and processes, continuously driving technological advancements in the use of TPU in shoe materials, and accelerating the commercialization of advanced technologies through its global presence. In February 2026, Lubrizol China’s Center of Excellence for Foaming Applications in Shanghai was officially established, becoming another key hub for foam technology innovation after Seoul, South Korea. By linking Lubrizol’s global materials R&D capabilities with regional application practices, the center fosters collaborative innovation with processors, equipment manufacturers, and brand owners to accelerate the transition from material design to commercial application. Through continuous investment and open collaboration, Lubrizol leverages its systematic technical capabilities and global resource network to support the steady improvement of performance, consistency, and sustainability in the running shoe midsole industry, while also continuing to drive the industrial development of TPU physical foam technology.