Tela de la Virus-Prueba para el desgaste médico

por Michael Johns, Project Manager | June 23, 2006
Breathable Viral Barrier (BVB)
Ahlstrom Corp. believes that protective clothing for doctors and paramedics made from its new line of virus-proof fabric will prove as potent a weapon as vaccinations in the battle against an avian influenza pandemic.

The Finnish company, whose U.S. operations are based in Windsor Locks, has reported rapid sales of surgical gowns, masks and other protective clothing made of its new breathable viral barrier.

The three-layer polymer fabric, made at Ahlstrom's nonwovens division, is designed to block entry of bacteria and viruses as small as .027 microns, including avian influenza, HIV and SARS, division President Paul Marold said. The H5N1 virus strain that has the world on edge is three times that size. "We're in an environment today where there is a lot of concern about pandemics and the passing of bacterias and viruses," Marold said.

"Vaccinations are one line of defense, but this is just as important."

The fabric consists of a soft inner layer and a repellent outer layer enclosing a breathable polymer membrane that lets humidity exit -- for the wearer's comfort -- but provides a much higher level of disease protection, said Marold, who is also Ahlstrom's worldwide general manager and vice president for medical fabrics.

Unlike the paper-based fabrics made at Ahlstrom, which are suspended in water and dried as thin layers on rollers, the new product is not "wet-laid," he explained. It is made by melting a plastic and spinning filaments thinner than a human hair into a dense web. The three layers are bonded together by a special adhesive as they dry.

The adhesive was a key achievement, Marold said.

"If we didn't have the proper adhesive, we'd essentially be making cardboard," he said. "You have to have a drapable product."

The breathable viral barrier was developed, in part, from the technology that Ahlstrom has long used to make paper and synthetic fabrics used in less protective medical attire and disposable hygienic wipes.

The effort began in 1998, Marold said, when Ahlstrom found itself ranked third or fourth in the growing but highly competitive medical nonwovens market. In cooperation with a customer, the Ohio-based medical products company now known as Cardinal Health Inc., Ahlstrom set out to capture a larger share.

"We spent a lot of time on: 'What are the performance requirements of the future?' " Marold said.

An experienced polymer scientist, Rahul Darmadhikary, who now is manager of technology for medical fibers, was hired to direct a development team of six scientists.