Comfort Factors of Protective Clothing: Mechanical and Transport Properties, Subjective Evaluation of Comfort

The purpose of this research was to determine the mechanical and transport properties contributing to fabric comfort for a series of nonwoven fabrics known to resist spray penetration and to relate those properties to the subjective evaluation of comfort.

Seven fabrics that may be used in protective apparel were evaluated for their comfort properties. One hundred percent cotton woven chambray with and without a fluorocarbon finish served as control fabrics. Five nonwoven test fabrics known to resist spray penetration were selected. Three spun-laced or spun-bonded test fabrics contained 100% olefin fibers with either a fluorocarbon finish or a polyethylene coating. Both woodpulp, polyester-blended nonwovens had a fluorocarbon finish. One woodpulp, polyester fabric also contained a flame retardant finish.

For each fabric, standard ASTM test methods were used to measure air and water vapor permeability, fabric weight, thickness, flexural rigidity, breaking load and elongation, and bursting and tear strengths. The Kawabata Evaluation System (KES) was used to provide an objective evaluation of hand characteristics. A panel of judges subjectively ranked the seven fabrics on smoothness, stiffness, stretchiness, thickness, weight, and hand.

The woodpulp, polyester nonwoven fabric with a commercial finish was found to be the nonwoven fabric having comfort characteristics closest to those of the chambrays. Among the nonwovens, it was ranked the highest for hand by the panel of judges while the olefin nonwoven fabric with the polyethylene coating was ranked as having the least desirable hand. The woodpulp, polyester nonwoven with a commercial finish was comparable to the chambray fabrics in terms of fabric stiffness. Both woodpulp, polyester fabrics had better air and water vapor transmission properties than did the other nonwoven fabrics evaluated.

According to the subjective evaluations, the stiffer and smoother the fabric, the less desirable the hand. The olefin nonwoven fabric with the polyethylene coating strongly exhibited both of these characteristics. In the subjective evaluation, it was ranked as having the least desirable hand. Both spun-bonded olefins had the lowest air and water vapor transport properties of the fabrics evaluated. Lack of these properties makes the olefin nonwovens a poor choice for comfortable protective apparel.

The nonwoven fabrics had significantly weaker tensile and bursting strength properties compared to the two chambray fabrics. There were no significant differences between wet and dry strengths of the nonwoven fabrics. Therefore, the presence of moisture would not be expected to cause premature fabric failure. The spun-bonded olefins were the most durable of the nonwoven fabrics evaluated.