There are two types of end-use applications for air filters—one is for building air conditioning units that are used to cool offices and large stores and another is for industrial air conditioning units, used for air conditioning of cleanrooms and workshops. The combined domestic consumption of air filtration media for both end uses was about 37,000 tons in Japan last year. Demand for filtration media, both for building air conditioners and industrial air conditioners, was sluggish in 2011.

Classified by performance basis, air filters are sorted into several categories: pre-filters, middle-class and high-efficiency filters and HEPA/ULPA filters. Different filter media are used for each. Nonwovens made from either synthetic fiber, glass fiber paper or mats are used as the filter medium. The quantity of nonwovens demanded for filter media in 2011 is estimated to be about 18,000 square meters.

Nonwoven manufacturers of filter media

Nonwovens made with chemical bonded and thermal bonded technologies are applied to the pre-filters. The major nonwovens manufacturers supplying these markets are Japan Vilene, Kanai Juyo Kogyo, Toyobo and Kurashiki Textile Manufacturing. Japan Vilene is the largest producer, maintaining more than 50% marketshare. Combined with sales of the second largest, Kanai Juyo Kogyo, the two companies control more than 80% of the marketshare.

Meltblown nonwovens are used for middle class and high-efficiency filters. The major nonwovens manufacturers of this material are Tapyrus, Japan Vilene and Kuraray; the marketshare occupied by these three companies is more than 90%. Tapyrus is the largest producer among them. Japan Vilene has produced filters  and all of the meltblown nonwovens made by Vilene are used internally to fuel the company’s filter business. Meanwhile, Tapyrus and Kuraray have not produced filters, and all of the meltblown nonwovens manufactured by these companies are sold to other filter makers.

In terms of air filters, although these products have been developed using nanofiber nonwovens by electrospinning, these nonwovens are not in high demand. Price competition for the air filters is very intense. Accordingly, the filters of nanofiber nonwovens are more expensive than the competition. Therefore, productivity  improvement and cost reductions will likely be necessary before these nanofiber-based nonwovens become more widely accepted.