Wednesday 4 July 2012

Nano-web Filters from India

Mahammad Safikur Rahman and Anil Kumar (above) of ATIRA (India) were developing high efficiency nonwoven filters using layers of nanofibre webs.  Ahmendabad’s Textile Industry Research Association had acquired a 1m wide Elmarco Nano-Spider pilot line as part of a strategy to become a center of excellence for nanofibres in India.  They were developing face-masks, cigarette filters, water filters and automotive air filters from multilayer structures of spunbonds, meltblowns and card webs with nanofibre webs sandwiched between layers as necessary.  

The nanofibre webs were being electrospun from PA6 and polyvinyl alcohol at between 20nm and 500nm diameter and laid directly onto spunbond PP prior to further lamination.  The permeability and thickness of the nanofibre layer was being controlled by varying the line speed between 0.5 and 2.5 m/min.  Automotive air filter paper had been coated with nanowebs at 1-9m/min giving air permeabilities varying from 236 l/m2/sec (untreated) down to 101 l/m2/sec at 1m/min coating speed.

Additional functionality could be met by adding carbon (active or nanotubes), silver or other chemicals to the electrospinning dope.  Barrier fabrics for medical use (SNS fabrics) had been developed with 2.5 times the water vapour permeability, yet 2.5 times the particle retention efficiency and 99.9% antibacterial and antiviral activity.

ATIRA, set up with government and private funding, welcomes collaboration with the world’s nonwovens industry.

(from EDANA Middle East Symposium  - Dubai - 14th and 15th Feb 2012)

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