High buoyancy composite materials

A method for forming a ballistic resistant material comprising:

• a) providing a first non-woven fibrous ply comprising an array of adjacent, unidirectionally oriented fibers or an array of adjacent, unidirectionally oriented tapes, or an array comprising both unidirectionally oriented fibers and unidirectionally oriented tapes, said first non-woven fibrous ply having an outer top surface and an outer bottom surface;
• b) applying a dry, solvent-free particulate polymeric binder to at least one surface of said first non-woven fibrous ply;
• c) applying at least one thermoplastic overlay onto a surface of said first non-woven fibrous ply, wherein said at least one thermoplastic overlay only partially covers said surface, and wherein said at least one thermoplastic overlay has a melting point below a melting point of said polymeric binder;
• wherein steps b) and c) are reversible;
• d) heating the at least one thermoplastic overlay to at least its softening temperature, and allowing it to bond to said surface of the first non-woven fibrous ply;
• e) applying a second non-woven fibrous ply onto the first non-woven fibrous ply on said at least one thermoplastic overlay, said second non-woven fibrous ply comprising an array of adjacent, unidirectionally oriented fibers or an array of adjacent, unidirectionally oriented tapes, or an array comprising both unidirectionally oriented fibers and unidirectionally oriented tapes, said second non-woven fibrous ply having first and second surfaces and said second non-woven fibrous ply comprising a dry, solvent-free particulate polymeric binder on at least one of said surfaces;
• and
• f) consolidating said first non-woven fibrous ply and said second non-woven fibrous ply under heat and pressure wherein at least a portion of the particulate polymeric binder of the first non-woven fibrous ply and at least a portion of the particulate polymeric binder of the second non-woven fibrous ply are melted, and whereby said binders bond the first and second non-woven fibrous plies together.

A method for forming a ballistic resistant material comprising:

• a) providing a first non-woven fibrous ply comprising an array of adjacent, unidirectionally oriented fibers or an array of adjacent, unidirectionally oriented tapes, or an array comprising both unidirectionally oriented fibers and unidirectionally oriented tapes, said first non-woven fibrous ply having an outer top surface and an outer bottom surface;
• b) applying a dry, solvent-free first particulate polymeric binder to at least one surface of said first non-woven fibrous ply;
• wherein said first particulate polymer binder only partially coats said first non-woven fibrous ply;
• c) applying a second non-woven fibrous ply onto the first non-woven fibrous ply, said second non-woven fibrous ply comprising an array of adjacent, unidirectionally oriented fibers or an array of adjacent, unidirectionally oriented tapes, or an array comprising both unidirectionally oriented fibers and unidirectionally oriented tapes, said second non-woven fibrous ply having first and second surfaces and said second non-woven fibrous ply comprising a dry, solvent-free second particulate polymeric binder on at least one of said surfaces, wherein said second particulate polymer binder only partially coats said second non-woven fibrous ply;
• and
• f) consolidating said first non-woven fibrous ply and said second non-woven fibrous ply under heat and pressure wherein at least a portion of the first particulate polymeric binder of the first non-woven fibrous ply and at least a portion of the second particulate polymeric binder of the second non-woven fibrous ply are melted, and whereby said binders bond the first and second non-woven fibrous plies together.