TECHNOLOGY AND INNOVATION CENTER

As an air conditioning equipment manufacturer dedicated to improving air quality, Daikin Industries develops various component parts for its air conditioning equipment. One of its most-groundbreaking achievements has been the world's first air filter utilizing a porous nanofibrous polymeric membrane. To learn more about it, we interviewed the TIC members who were involved in the development of this trailblazing air filter as part of the global expansion of the Daikin filter business: Hideyuki Kiyotani, Kunihiko Inui, and Yoshiyuki Shibuya. While recounting the filter's evolution, they shared the challenges that they faced during the initial development stages, the joys of innovation, and the unique episodes specific to TIC.

――Please tell us where your career paths at Daikin have taken you?

Kiyotani: Since joining in 1995, I've always have been involved in the development of air filters. There was a period when I temporarily worked on developing O-rings, and the team itself was dispatched to another company, but even then, I continued performing filter-related work there too.

Inui: I joined in 1992 and was initially assigned to the Product R&D Department, where I investigated the properties of plastics. Later, when it came time to process fluoropolymers, I transferred to the Filter Group. Currently, I am working separately from the development team in support of patent application procedures.

Shibuya: I joined the company in 1980 and was originally put in charge of work other than filters. However, in 1996, I was given responsibility for the development of filter materials for air filters. From 2008, I spent about two years involved in setting up filter manufacturing equipment at a Daikin Group company, American Air Filter (AAF). Later, I worked on joint development of filter materials and filters. Upon reaching retirement age in 2019, I was rehired and remain involved with development.

Inui: In terms of specialization, it's crucial for team members to collaborate across various fields, from knowledge of fluoropolymer materials to processing, air filter expertise, and air quality evaluation tests. At TIC, the groups involved in actual filter development conduct daily R&D activities and operate under an organizational structure that includes members proficient not only in chemistry but also in information and sensing systems.

――Daikin successfully developed the world's first PTFE HEPA filter. What are its special characteristics, and what advantages does Daikin have over other companies?

Kiyotani: In 1995, Daikin released the PTFE HEPA filter. Until then, HEPA filters utilized glass fibers for particle capture, but we were the first in the world to replace them with PTFE. We discovered that by rapidly stretching the filter material, it could form a porous membrane consisting of ultrathin PTFE fibers suitable for air filtration. Consequently, we commercialized it as a nanofiber-level air filter.

Owing to its history of selling resin materials in the Chemicals Division, one of Daikin's strengths lies in its ability to adapt to various arrangements and processing methods. Additionally, the collaboration with Group companies, such as AAF and Nippon Muki, is another advantage enabling production under an integrated system that extends to the final product, the filter units.

――Are there any episodes in which you overcame hardships during development or other anecdotes that you would care to share?

Kiyotani: When I joined the company, the mass production system was not yet fully established. I remember struggling with production because there were instances of product contamination, which led to products being rejected during inspections and discarded as defective items.

――Would you say that being in competition with them might pose a challenge to developing filters in collaboration with other chemical manufacturers?

 

Kiyotani: There is certainly that aspect to consider. It can be challenging to determine which companies to collaborate with for joint development. It's necessary to establish a division of responsibilities, such as "we'll handle this aspect of the field, but not that one," before engaging in collaboration. However, when we initially considered developing air filters with PTFE, we had always intended to have downstream products of our own.

――Please share your outlook on the future of the filter industry.

Kiyotani: Looking ahead, our goal is to further enhance the quality of air with Daikin's filters by utilizing them in various fields.

Inui: PTFE filters currently offer the lowest pressure drop, helping to reduce energy loss and making them environmentally and energy efficient. We aim to contribute on a global scale by leveraging these benefits.

Shibuya: We will continue to develop PTFE filters to further reduce pressure drop and contribute to energy efficiency. PTFE filters are used in semiconductor devices and cleanrooms because they do not expel impurities. However, the market for PTFE filters is still relatively small. Therefore, we aim to enhance our technology through collaboration with resin processing manufacturers, expand our market share, and enthusiastically compete.

――Finally, do you have a message to convey to those considering joining Daikin?

Inui: I come from a background in chemistry and started with material development for fluoropolymers, and now I handle patent-related tasks. At Daikin, engineers have the opportunity to excel in a wide range of fields. In the future, I hope to see the development of various high-performance materials, not just fluoropolymers. With the expected growth in the semiconductor industry, there's potential for Daikin to contribute as a cornerstone supporting cutting-edge technology.

Kiyotani: In terms of fundamental research, PTFE filters operate at the nanoscale, where physical phenomena differ from conventional macro-scale understanding. For instance, at the nanoscale level, air slips and reduces resistance, but the theoretical explanation of this phenomenon remains elusive. I believe there will be many more new discoveries ahead. We welcome participation from those interested in such research endeavors.

Shibuya: Daikin not only operates in the air conditioning business but also extends its filter business worldwide through its Group companies. Therefore, I believe that there are exciting opportunities to work in various countries. Personally, I have had business trips for technical meetings and technical services to a total of 13 countries, including countries in the EU and Asia. For those who aspire to work overseas, who are proficient in languages, and who seek opportunities to excel, I believe that this workplace is highly attractive. If you are interested, come work together with us!

※The information and profiles are based on the time of the interview.