Multi-purpose air permeable composites
AssigneeHughes Aircraft Company
InventorsRobin W. Rosser, Leon B. Keller
Life of this patent
Estimating the term…
Abstract
Composites, comprising organic polymeric fibers and solid particles, are described which exhibit a wide range of functional characteristics. The materials are light in weight, structurally strong and are air permeable. The fabrication of protective clothing for use in chemical warfare environments is a typical use for which these composites are suitable.
Claims27
A tailorable air permeable composite, suitable for use in the fabrication of protective clothing, filters and other structural membranes comprising selected solid particles interstitially located within a web-like network of interconnected, branched organic fibers wherein said fibers are formed from solution in the presence of said particles and coil about and entrap said particles in situ during the formation of said fibers, without coating said particles, thereby forming a stable solid-in-solid suspension that is structurally strong, porous and light in weight.
A tailorable air permeable composite comprising solid microscopic particles interstitially positioned within a web-like network of submicroscopic interconnected, branched organic fibers wherein said fibers as formed coil about said particles thereby entrapping said particles, and intertwine with each other, to form a stable structurally strong lightweight porous material.
An air permeable absorptive fabric for use in the fabrication of protective clothing prepared by the process of:
- providing a polymer-solvent solution by dissolving a selected fiber forming polymer, or mixture of polymers, in an organic processing solvent at an elevated temperature;
- adding absorptive solid particles to said solution and mixing said particles with said solution to form a suspension of said particles in said solution;
- applying constant agitation to said suspension while lowering its temperature to cause fibers to be formed from said solution-suspension which encircle, coil around and entrap said solid particles as they precipitate from said solution into a three-dimensional web-like fibrous mass;
- and
- subsequently removing traces of said processing solvent by extracting said solvent with a low boiling solvent and vacuum baking said fibrous mass, thereby providing a solid-in-solid composite fabric that is chemically absorptive.
A process for preparing multi-purpose air permeable composites comprising the steps of:
- forming a solvent-suspension of selected solid particles in a fiber forming polymer-solvent solution at an elevated temperature;
- applying constant agitation to said suspension while lowering the temperature of said suspension thereby causing polymeric fibers to form, encircle, coil about said particles, and entrap said particles while said particles are coprecipitated from said solvent suspension with said fibers;
- and
- subsequently extracting said solvent from said coprecipitated particles and fibers to thereby yield a three-dimensional web-like network of polymeric fibers having solid particles permanently entrapped within the interstices of said network that exhibits functional characteristics commensurate in scope to the functional characteristics of said solid particles.
A process for forming a fiber-solid particle mass composite having improved air permeability and structural characteristics which comprises:
- (a) providing a fiber forming solution;
- (b) suspending selected solid particles in said solution characterized in that the mean diameter of said particles is greater than the mean diameter of fibers which form from said solution;
- and
- (c) treating said solution in a manner sufficient to cause fibers to precipitate therefrom and simultaneously entrap said particles thereby removing said particles from said solution to form a three-dimensional fiber-solid particle mass which retains its structural integrity without the aid of a resin or other particle-to-fiber bonding agent.
A process for preparing an air permeable composite fiberized cloth comprising the steps of:
- providing a piece of open weave cloth;
- forming a solvent-suspension of selected solid particles in a fiber forming polymer-solvent solution at an elevated temperature;
- immersing said cloth in said solvent-suspension;
- applying constant agitation to said cloth to provide constant agitation to said suspension while lowering the temperature of said suspension thereby causing polymeric fibers to form, encircle, coil about said particles, and entrap said particles while said particles are coprecipitated from said solvent-suspension with said fibers on said open weave cloth and into the open spaces thereof;
- and
- subsequently extracting said solvent from said coprecipitated particles and fibers and said cloth to thereby yield a fiberized cloth comprising a three-dimensional web-like network of polymeric fibers having solid particles permanently entrapped within the interstices of said network, wherein said fiberized cloth exhibits functional characteristics commensurate in scope with the functional characteristics of said solid particles.
An air permeable absorptive fabric for use in the fabrication of protective clothing prepared by the process of:
- providing a piece of open weave cloth;
- providing a polymer solvent solution by dissolving a selected fiber forming polymer, or mixture of polymers, in an organic processing solvent at an elevated temperature;
- adding absorptive solid particles to said solution;
- immersing said cloth in said solution containing said particles and agitating said cloth to mix said particles with said solution to form a suspension of said particles in said solution;
- applying constant agitation to said cloth to provide constant agitation to said suspension while lowering the temperature of said suspension to cause fibers to be formed from said solution-suspension which encircle, coil around and entrap said solid particles as they precipitate from said solution onto said open weave cloth to form a fiberized open weave cloth;
- and
- subsequently removing traces of said processing solvent by extracting said solvent with a low boiling solvent and vacuum baking said fiberized open weave cloth, thereby providing a solid-in-solid composite fabric that is chemically absorptive and comprises said open weave cloth fiberized with said polymer and said solid particles entrapped therein.
Dependencies are inferred from the claim text.