Abstract: Ballistic resistant composite materials having high positive buoyancy in water are provided. More particularly, provided are foam-free, buoyant composite materials fabricated using dry processing techniques. The materials comprise fibrous plies that are partially coated with a particulate binder that is thermopressed to transform a portion of the binder into raised, discontinuous patches bonded to fiber/tape surfaces, while another portion of the particulate binder remains on the fibers/tapes as unmelted particles. The presence of the unmelted binder particles maintains empty spaces within the composite to materials which increases the positive buoyancy of the composites in water.

Abstract: Ballistic resistant composite materials having high positive buoyancy in water are provided. More particularly, provided are foam-free, buoyant composite materials fabricated using dry processing techniques. The materials comprise fibrous plies that are partially coated with a particulate binder that is thermopressed to transform a portion of the binder into raised, discontinuous patches bonded to fiber/tape surfaces, while another portion of the particulate binder remains on the fibers/tapes as unmelted particles. The presence of the unmelted binder particles maintains empty spaces within the composite materials which increases the positive buoyancy of the composites in water.

Abstract: A method for improving the translation efficiency of fiber strength into composite strength is provided. A single unidirectional tape, single unidirectional fiber web or a stack of unidirectional web/unidirectional tape plies formed from partially oriented fibers/tapes is primed under mild conditions followed by subjecting the primed plies to an axial extension stress in the axial fiber direction of each fiber ply by passage through a compression apparatus. The axial extension stress extends the fibers, strengthening them, while also compacting the plies together and thereby forming a composite having improved strength. Production yield is improved by avoiding maximal fiber stretching and thereby avoiding typical manufacturing loss, and low weight composite armor having increased strength is achieved.

Abstract: Multi-ply, hybrid composite materials useful in the formation of thin walled, hollow, tubular articles having improved resistance to hoop stress. Two different, single-ply pre-pregs are impregnated with binders and laminated together with the fibers of the layers oriented at a bias relative to each other. The hybrid composite is rolled into a tubular article having excellent strength uniformity along the full length of the tubular article.

Abstract: A method for improving the translation efficiency of fiber strength into composite strength is provided. A single unidirectional tape, single unidirectional fiber web or a stack of unidirectional web/unidirectional tape plies formed from partially oriented fibers/tapes is primed under mild conditions followed by subjecting the primed plies to an axial extension stress in the axial fiber direction of each fiber ply by passage through a compression apparatus. The axial extension stress extends the fibers, strengthening them, while also compacting the plies together and thereby forming a composite having improved strength. Production yield is improved by avoiding maximal fiber stretching and thereby avoiding typical manufacturing loss, and low weight composite armor having increased strength is achieved.

Abstract: Ballistic resistant composite materials having high positive buoyancy in water are provided. More particularly, provided are foam-free, buoyant composite materials fabricated using dry processing techniques. The materials comprise fibrous plies that are partially coated with a particulate binder that is thermopressed to transform a portion of the binder into raised, discontinuous patches bonded to fiber/tape surfaces, while another portion of the particulate binder remains on the fibers/tapes as unmelted particles. The presence of the unmelted binder particles maintains empty spaces within the composite materials which increases the positive buoyancy of the composites in water.

Abstract: Viscoelastic, lightweight composite armor that is resistant to backface deformation, and to a method for evaluating the effectiveness of composite armor in resisting backface deformation. The index of retraction of a composite is determined by evaluating the degree of composite retraction at the site of impact of projectile after movement of the projectile is stopped. The degree of retraction indicates the ability of the composite to resist backface deformation.

Abstract: Ballistic resistant composite materials having high positive buoyancy in water are provided. More particularly, provided are foam-free, buoyant composite materials fabricated using dry processing techniques. The materials comprise fibrous plies that are partially coated with a particulate binder that is thermopressed to transform a portion of the binder into raised, discontinuous patches bonded to fiber/tape surfaces, while another portion of the particulate binder remains on the fibers/tapes as unmelted particles. The presence of the unmelted binder particles maintains empty spaces within the composite materials which increases the positive buoyancy of the composites in water.

Abstract: Multi-ply, hybrid composite materials useful in the formation of thin walled, hollow, tubular articles having improved resistance to hoop stress. Two different, single-ply pre-pregs are impregnated with binders and laminated together with the fibers of the layers oriented at a bias relative to each other. The hybrid composite is rolled into a tubular article having excellent strength uniformity along the full length of the tubular article.

Abstract: Viscoelastic, lightweight composite armor that is resistant to backface deformation, and to a method for evaluating the effectiveness of composite armor in resisting backface deformation. The index of retraction of a composite is determined by evaluating the degree of composite retraction at the site of impact of projectile after movement of the projectile is stopped. The degree of retraction indicates the ability of the composite to resist backface deformation.

Abstract: A process for forming defect-free fibrous composite materials. More particularly, a process for forming blister-free fibrous composites without having to actively monitor or control blister formation during molding of a stack of plies, and to blister-free composite materials fabricated therefrom. Fibrous plies are coated with a dry, particulate binder without impregnating the plies with the binder. Gaps between fibers/tapes allow air to diffuse out of the stack without affecting the binder coating, thereby avoiding blister formation.

Abstract: Ballistic resistant composite materials having high positive buoyancy in water are provided. More particularly, provided are foam-free, buoyant composite materials fabricated using dry processing techniques. The materials comprise fibrous plies that are partially coated with a particulate binder that is thermopressed to transform a portion of the binder into raised, discontinuous patches bonded to fiber/tape surfaces, while another portion of the particulate binder remains on the fibers/tapes as unmelted particles. The presence of the unmelted binder particles maintains empty spaces within the composite materials which increases the positive buoyancy of the composites in water.