Rengo Co., Ltd. has announced the development of a new flame- and heat-resistant sheet in collaboration with Marusan Paper Mfg. Co., Ltd.
The innovation combines mineral-derived rock wool with Rengo’s proprietary FineNatura™ cellulose nanofiber (CNF), resulting in a lightweight, high-performance material.
FineNatura™, produced since 2021 at Rengo’s pilot plant, is a chemically unmodified cellulose nanofiber characterized by its ultrafine structure. When blended with rock wool and molded into sheets a few millimeters thick, the resulting material offers excellent thermal insulation, flame resistance, and sound absorption.
FineNatura™ appearance. Source: Rengo
Compared to conventional sheets used in construction and related sectors, the new product delivers superior strength, rigidity, and soundproofing—particularly in blocking airborne noise. Its low weight and ease of handling further enhance its versatility.
Rengo and Marusan Paper plan to explore commercialization opportunities across a range of industries, promoting the sheet as a sustainable and multifunctional solution for next-generation building and industrial materials.
About Rengo
Rengo Co., Ltd. is a leading Japanese packaging manufacturer specializing in corrugated and paperboard products. Known for its innovation in sustainable materials, Rengo also develops advanced cellulose nanofiber technologies such as FineNatura™.
About Marusan Paper
Marusan Paper Mfg. Co., Ltd., a Rengo subsidiary, produces linerboard and specialty fiber-based materials. Based in Fukushima, the company focuses on flame-resistant, high-performance sheets for industrial use.
