A quilted fabric containing high surface area carbon fibers is made by uniting a central layer of flexible activated carbon fibers between a pair of outer layers of reinforcing fabric, positioned on each side of the layer of activated flexible carbon fibers, with a network of quilting stitching. The quilted fabric thus made is useful for fabricating protective clothing or gas masks for use by personnel who must enter areas which may contain noxious gases, or for face masks for combatting the air pollution problem. The quilted fabric makes possible the use of spun yarns of activated carbon fabric which have, per se, low tensile strength, but which can be made more economically than continuous filaments of higher tensile strength.
A laminated, highly sorbent, active carbon fabric which is permeable to mture vapor while sorbing substantial quantities of toxic chemical vapors, and process of making such a laminated fabric.
A material suitable for fabricating chemical warfare protective garments comprises at least one layer of an activated woven carbon fabric plus a body-side high absorbency rayon layer interposed between said at least one woven carbon fabric layer and the wearer's body. An innermost body-side layer of a ribbed fabric such as corduroy underlays the carbon and rayon layers to channel vapor away from the material. Chemical warfare protective garments having extended use life can be fabricated from this material.
An infusiblized, or infusiblized and slightly carbonized fiber of optically anisotropic pitch type is combined with a phenolic resin fiber to produce a high bulk density carbon fiber structure in the form of a laminate of mutually entangled carbon fiber sheets with improved handleability of fiber sheets and improved stability of a laminate structure formed through entanglement. A high flexural strength carbon-carbon composite material with a high volume fiber content is produced by impregnation with a precursor of carbon and subsequent carbonization of the carbon fiber structure of the kind as described above or a fiber laminate of mutually entangled sheets of the infusiblized, or infusiblized and slightly carbonized fiber of optically anisotropic pitch type blended with the phenolic resin fiber.
A composite material suitable for use as CBW protective clothing comprises, in combination: an outer layer (1) of an abrasion-resistant, water-repellent material; an intermediate layer (2) comprising activated charcoal cloth treated to provide liquid-repellency; and an inner layer (3) of an abrasion-resistant material laminated to the intermediate layer. This composite is light, breathable and has low thermal insulation properties, but provides good chemical protection.
Fibers having a high degree of flexibility and handleability are produced by oxidizing fibers spun from a carbonaceous pitch which has been transformed, in part, to a liquid crystal or so-called "mesophase" state to an oxygen content of from 17 per cent by weight to 30 per cent by weight. Because of their strength and handleability, these highly-oxidized fibers can be easily processed at high speeds by means of conventional yarn-transport systems, and readily woven or knit into cloth. Such cloth may then be heat treated to produce carbon or graphite cloth.
