Kowa Company Ltd. and the National Agricultural and Food Research Organization (NARO) recently announced they have successfully developed the technology to industrialise the silk thread emitted by a bagworm moth larva, which is touted as being “the toughest natural fibre that even surpasses the so-called strongest silk from spiders.” Kowa and NARO are continuing with their joint research on methods to mass produce bagworm silk, while aiming for its early commercialisation through corporate tie-ups.

Development trajectory

Although the predominant image of Kowa is a manufacturer of general pharmaceutical products both in Japan and worldwide, it actually began as a wholesaler of cotton cloth when it was founded in 1894. Kowa is now a conglomerate encompassing a wide range businesses dealing in health and the environment. Its textiles business has been actively developing natural materials, with a focus on researching functional silk. Amongst the dozens of unknown and unharnessed living organisms it has studied, bagworm silk is of particular interest to Kowa. The company’s research shows that bagworm silk surpasses spider silk in terms of functionality and performance.

It has set up the Kowa Research Laboratories for Advanced Science near NARO’s head office in Tsukuba City, Ibaraki Prefecture, to facilitate the ongoing joint research with NARO since 2016.

Advantages of bagworm silk thread

Bagworm silk has ideal properties as a structural material; it surpasses spider silk in elasticity, snap resistance and toughness. So far the issues affecting its mass production have been breeding the bagworms and mass producing their silk. However, efforts to establish separate methods for the mass and artificial breeding of bagworms and efficient silk collection have opened up a path to industrialisation.

Possible uses for bagworm silk include in protective clothing and sports products, and in materials used in airplane and car bodies. Equipped with both strength and elasticity, bagworm silk has immense hidden potential in a multitude of applications.