Breathable non-woven composite barrier fabric and fabrication process

A process for forming an adhesive bonded non-woven composite fabric having a moisture or vapor transmission rate of greater than about 240 grams per square meter for 24 hours at about 75.degree. F. and about 65% relative humidity, said fabric providing a barrier to passage of biological liquid when the composite fabric is subjected to contact with synthetic blood at 0 psi for 5 minutes followed by synthetic blood contact at 2 psi (13.6 kpa) for 1 minute followed by synthetic blood contact at 0 psi for 54 minutes, said composite fabric exhibiting no visible penetration of the synthetic blood;

• said composite fabric having a breaking strength of at least 14 pounds per inch;
• said process comprising:
• unwinding at least one continuous thermoplastic non-woven web and at least one continuous thermoplastic microporous film;
• inserting adhesive bonding materials at multiple spaced-apart locations between the continuous thermoplastic non-woven web and the continuous thermoplastic microporous film;
• contacting a side of the at least one thermoplastic non-woven web adjacent to said adhesive bonding material to a side of the continuous thermoplastic microporous film;
• continuously transporting said contacted web and film adjacent to said adhesive bonding material through an adhesive curing zone, said curing zone providing a dwell time sufficient to cure said adhesive without degrading either the film or webs.

A non-woven composite fabric comprising:

• a microporous thermoplastic film having at least one film surface adhesive bonded to a layer of non-woven thermoplastic material, the bonding occurring at multiple spaced-apart locations through the agency of specifically introduced adhesive material;
• said composite fabric having a barrier to passage of biological liquid when the composite fabric is subjected to contact with synthetic blood at zero psi for 5 minutes followed by synthetic blood contact at 2 psi (13.6 kpa) for one minute followed by synthetic blood contact at zero psi for fifty-four minutes, said composite fabric exhibiting no visible penetration of synthetic blood;
• the composite fabric providing a barrier to viral penetration when the composite fabric is subject to contact with .O slashed.X174 bacteriophage suspension at a titer of 10.sup.8 PFU/mL for 5 minutes with no applied pressure, 1 minute at 13.8 kPa (2.0 PSIG), and 54 minutes with no applied pressure;
• and
• said non-woven composite fabric having a moisture or vapor transmission rate of greater than about 450 grams per square meter for twenty-four hours at about 75 degrees F and about 65% relative humidity.

A process for forming an adhesive bonded non-woven composite fabric having a moisture vapor transmission rate of greater than 450 grams per square meter for 24 hours at about 75.degree. F. and about 65% relative humidity, said fabric providing a barrier to passage of biological liquid when the composite fabric is subjected to contact with synthetic blood at 0 psi for five minutes followed by synthetic blood contact of 2 psi (13.6 kpa) for 1 minute followed by synthetic blood at 0 psi for 54 minutes, said composite fabric exhibiting no visible penetration of the synthetic blood;

• said composite fabric providing a barrier to viral penetration when the composite is subject to contact with .O slashed.X174 bacteriophage suspension at a titer of 10.sup.8 PFU/mL for five minutes with no applied pressure, one minute of 13.8 kpa (2.0 PSIG), and fifty-four minutes with no applied pressure;
• said process comprising:
• unwinding at least one continuous thermoplastic non-woven web and at least one continuous thermoplastic microporous film;
• inserting adhesive bonding materials at multiple spaced apart locations between the continuous thermoplastic non-woven web and the continuous thermoplastic microporous film;
• contacting a side of the at least one thermoplastic non-woven web adjacent to said adhesive bonding materials to a side of the continuous thermoplastic microporous film adjacent to said adhesive bonding material;
• and
• continuously transporting said contacting web and film adjacent to said adhesive bonding materials through an adhesive bonding zone providing a dwell-time sufficient to cure said adhesive without degrading either film or webs.

A non-woven composite fabric comprising:

• a microporous film having at least one film surface coated with a thin layer of breathable urethane and one film surface bonded to a layer of thermoplastic materials, the bonding occurring at multiple spaced apart locations through the agency of specifically introduced adhesive material;
• said composite fabric having a barrier to passage of biological liquid when the composite fabric is subjected to contact with synthetic blood at zero psi for 5 minutes followed by synthetic blood contact at 2 psi (13.6 kpa) for one minute followed by synthetic blood contact at zero psi for fifty-four minutes, said composite fabric exhibiting no visible penetration of synthetic blood;
• the composite fabric providing a barrier to viral penetration when the composite fabric is subject to contact with .O slashed.X174 bacteriophage suspension at a titer of 10.sup.8 PFU/mL for 5 minutes with no applied pressure, 1 minute at 18.8 kPa (2.0 PSIG), and fifty-four minutes with no applied pressure;
• a non-woven composite fabric having a moisture or vapor transmission rate of greater than about 450 grams per square meter for twenty-four hours at about 75.degree. F. and about 65% relative humidity;
• and
• the microporous film coated with breathable urethane having resistance to low surface tension liquid wet out.