The vapor permeability and wear resistance of full-body protective garments

Abstract

Studies of the solvent vapor permeability of polymeric materials that may be used in the construction of full-body protective garments were completed. These investigations demonstrated that vapor permeability is a function of polymer type, the nature of the solvent and is directly proportional to solvent concentration. The solvents used in this study were: aniline, carbon disulfide, carbon tetrachloride, cellosolve, phenol and toluene. The polymers tested were: natural rubber, supported NBR nitrile, unsupported NBR nitrile, Saranex-laminated Tyvek and Viton. Other studies measured the wear resistance of these materials and their durability to repeated laundering. The results of these studies showed that both Viton, a perfluorinated hydrocarbon and Saranex-laminated Tyvek, a laminated polyethylene spun-bound fiber, both demonstrated superior permeation resistance to most solvent vapors. However, Saranex-laminated Tyvek showed poor stability to laundering and clearly is suitable only as a disposable garment material. Natural rubber, although resistant to repeated cleanings, was the poorest of the materials tested in terms of permeation resistance to solvent vapors. The other two polymers occupy intermediate positions between natural rubber and Viton or Saranex-laminated Tyvek. Each polymer was subjected to three wear tests; creasing, stretching, and abrasion. To perform these tests, a wear test apparatus was designed and constructed specifically for this purpose. In general, Saranex-laminated Tyvek and Supported NBR Nitrile exhibited the poorest resistance to wear especially to creasing and stretching. Of the remaining polymers, both Viton and natural rubber performed extremely well and showed excellent resistance to wear in all three tests. Based on the vapor permeation, laundering and wear tests, Viton demonstrated the best overall performance. Saranex-laminated Tyvek shows superior vapor permeation resistance but poor resistance to wear and laundering. It is obviously best suited for use as a disposable garment. Finally, the other three polymers, natural rubber and supported and unsupported NBR nitrile, while useful under special circumstances, may not be as suitable as Viton or Saranex-laminated Tyvek as general purpose materials.