Toray Industries, Inc., announced today that it has developed a new polyvinylidene fluoride (PVDF) ultrafiltration (UF) membrane with exceptional virus removal rate and high water permeability for water treatment. It can thereby contribute to safe and economical water supplies treated with minimal energy for various applications, from food and beverages through wastewater reuse. Toray will accelerate application testing with a view to commercialization.
Toray has been offering PVDF UF membrane, in which the company pursued high strength and high water permeability, for water treatment. In recent years, there has been growing expectations for UF membranes to enhance pathogenic virus removal and water permeability without reducing safety or increasing costs. It has been the difficult problem for years to develop these UF membranes because reducing pore diameters to remove viruses make membrane resistance high, which results in decreasing water permeability.
Toray overcame that challenge by improving its technology in following two key respects.
1. Using phase separation control technology to create a uniformly dense structure
Toray focused on minimizing coarse voids exceeding 100 nm through which viruses can easily pass. By laminating layers which have homogeneous pore size distribution, Toray create a uniform dense structure without coarse voids. This uniform dense structure made it possible to create thinner dense structure than conventional UF membrane and showed 99.99% removal of the Essherichia coli phage MS2, which has a diameter of around 27 nanometers.
2. Innovative hollow fiber membrane manufacturing technology
Dense structure increases resistance and impede water flow. Toray resolved that issue by using a proprietary hollow fiber membrane process technology built on the experience in water treatment and artificial kidney applications to create a thin, uniformly dense structure. Toray achieved excellent virus removal and water permeability (see figures 1 and 2) by increasing porosity in whole membrane except for the uniform dense structure, thus securing more water channels and boosting overall membrane permeability.
The Toray Group is leveraging its innovative technologies and advanced materials in its drive to provide universal access to water and air and help restore the environment in keeping with the Toray Group Sustainability Vision and Toray Vision 2030, under which it pursues sustainable and healthy growth.
In the years ahead, Toray will do much In keeping with its corporate philosophy of contributing to society by creating new value with innovative ideas, technologies, and products. It will help pave the path toward a recycling-based economy by scaling up, socially implementing, and evaluating its technology over the long term. It also looks to accelerate research into diverse applications extending from food and beverages to reusing wastewater.