A titan-modified hydroxyapatite photocatalyst developed by the University of Tokyo and Fujitsi Laboratories has been applied to nonwovens by Kurashiki Textile Manufacturing in Japan.

These are being used in antimicrobial filter media and protective masks, and their efficacy in blocking bacteria and influenza virus has been proven by several testing institutes in Japan.

A mask tested for effectiveness at blocking staphlococcus aureas bacteria showed a bacteriostatic activity value of less than 2.2, or 99% efficiency.

Irradiation and chemical graft technologies have also been applied to a new type of chemically-reactive media by Kurashiki.

Employed as a filter media this has a high ion-exchange capacity, the company reports.

When modified by sulfonation or the application of amine, the nonwoven achieves rapid adsorption of gases for use in industrial clean rooms. In liquid filtration uses, many metal ions can also be rapidly adsorbed.

Kurashiki is also producing a halogen and phosphate free anti-flammable nonwoven for air filter media. The company’s flame retardant system can be applied to many types of substrate, including pleatable types which can be customised in terms of weight and air permeability. Applications are in automotive cabin filters, HVAC and buildings.