Rengo Co., Ltd. (Head Office: Kita-ku, Osaka; Chairman, President & CEO: Kiyoshi Otsubo) and SunRising Ltd. (Head Office: Takamatsuhigashi, Izumisano; President: Manabu Hatsuarashi) announce the joint development of a new plum wood charcoal paper yarn known as “PRUBONE” that boasts superior deodorant, antibacterial and virus-resistant properties.

Paper yarn is a thread of twisted finely sliced washi paper. PRUBONE is manufactured using washi with added powder from carbonized plum seeds, which are a high-volume waste product in Wakayama prefecture's renowned plum production. A totally new paper yarn has now been produced by blending washi with Cellgaia, a high-functional fiber possessing advanced antibacterial, deodorant, and virus-resistant properties which is also capable of rendering Japanese cedar allergens inactive.

Rengo's patented fiber Cellgaia is renowned for its advanced antibacterial and deodorant properties. To date it has been successfully used in a wide range of products including disposable masks, disposable pet undersheets, light incontinence pads and drainage net trash bags. However, it had not been applied in textiles, which require a more delicate texture.

SunRising had focused its attention on the deodorant effect achieved through carbonization of plum seeds, which were an industrial waste product. They sold clothing accessories that effectively utilized paper yarn made with plum wood charcoal powder, however they were unable to provide the antibacterial function that would be an effective sales point in the textile field.

With the combined knowledge of the two companies, Rengo's expertise in paper manufacturing from long years of experience, and the incorporation of Mino washi technology, they have successfully developed a new soft-textured yet strong paper yarn. In comparison with earlier paper yarns containing only plum wood charcoal powder, the addition of Cellgaia added superior anti-bacterial properties and further enhanced the deodorant capability.

Clothing accessories (scarves, etc.) made from this new plum charcoal paper yarn PRUBONE have already been commercialized under the PRUBONE brand name. They are sold through distributors such as the Japanese Consumers' Co-operative Union, JP Mitsukoshi Merchandising, Dinos Cecile Direct Shopping and regional Co-Ops and have proven very popular.

Cellgaia is creating high added-value for “Cool Japan” products developed through the blending of world-renowned Japanese technologies. We can look forward to even more applications for Cellgaia in the future.