Daiwabo Neu Develops Caustic Soda-Free Dyeing Technology

Daiwabo Neu Co., Ltd. has developed a dyeing and processing technology that uses no caustic soda (sodium hydroxide). Since neutralization during wastewater treatment is unnecessary, this innovative process reduces the environmental load, such as lower water consumption. The company applied for patents for its new technology this February, and hopes to promote practical use including product developments in fiscal 2019 ending in March 2020.

Caustic soda is one of the basic chemicals essential for dyeing and processing, and is widely used for the scouring and bleaching of textiles and the preparation of dye liquor. But depending on the method of application, the fibers might be damaged by its strong alkalinity, and disposal of the spent solution requires neutralization, so the environmental load of wastewater treatment is not small.

Daiwabo Neu has been conducting research on components replacing caustic soda, and succeeded in developing a dyeing and processing technology that uses no caustic soda on cotton materials. Products processed with this new technology have the same level of water absorption and whiteness as conventionally processed articles, and their texture is also said to be outstanding as no damage is incurred to the fibers. This technology can be applied to cotton and other cellulosic fibers, as well as to protein fibers such as silk and wool, which are weak to alkalinity, so it can be applied to cotton/silk and cotton/wool blends.

Since wastewater treatment can also eliminate the neutralization process, it is expected to lessen environmental impact, such as reducing the amount of chemicals and water used. In regard to the dyeing and processing ability and environmental load reduction effects of this new technology, experiments to verify and confirm its effects have been conducted at cooperative Japanese dyehouses.

Since two years ago, Daiwabo Neu has been promoting the “Ecology Sustainable Project”, undertaking developments with the environment taken into consideration. The new caustic soda-free dyeing and processing technology was developed as part of this project.