A composite core material and methods for making same are disclosed herein. The composite core material comprises mineral filler discontinuous portions disposed in a continuous encapsulating resin. Further, the method for forming a composite core material comprises the steps of forming a mixture comprising mineral filler, an encapsulating prepolymer, and a polymerization catalyst; disposing the mixture onto a moving belt; and polymerizing said encapsulating prepolymer to form a composite core material comprising mineral filler discontinuous portions disposed in a continuous encapsulating resin.

A method of forming carbon-carbon composites includes molding carbon fibers with a compound comprising a blend of benzoxazine resin and cyanate ester resin; and pyrolyzing the compound to form the carbon-carbon composite. A carbon-carbon composite includes carbon fibers impregnated with a compound comprising a blend of benzoxazine resin and cyanate ester.

Disclosed is a method for manufacturing gas cylinders. The disclosed method for manufacturing gas cylinders comprises: a) a step of producing a liner using a liner blower machine; b) a step of applying an adhesive to the threads of the produced liner; c) a step of coupling a bushing to the threads of the liner; d) a step of leaving the liner having undergone step c) for 30 minutes to 2 hours at room temperature so as to naturally harden the adhesive; e) a liner-flaming step of heat-treating the outer surface of the liner with plasma; f) a step of coupling a shaft to the liner; g) a winding step of mixing multiple fiberglass strands with a resin and a hardening agent, and wrapping the mixture around the outer surface of the liner; h) a dry-hardening step of drying the cylinder made of the composite material and having undergone the winding step for 70 to 90 minutes at a temperature of 70 C. to 90 C.; i) a cooling step of leaving the cylinder made of the composite material for 15 to 40 minutes at room temperature so as to lower the surface temperature of the cylinder having undergone the dry-hardening step to a level of 35 C. or lower; j) a step of separating the shaft from the cylinder made of the composite material; k) a step of assembling a valve to the bushing installed in the cylinder made of the composite material; and l) a step of checking the state of the gas cylinder including the cylinder made of the composite material.

A composite core material and methods for making the same are disclosed herein. The composite core material comprises mineral filler discontinuous portions disposed in a continuous encapsulating resin. Further, the method for forming a composite core material comprises the steps of forming a mixture comprising mineral filler, an encapsulating prepolymer, and a polymerization catalyst; disposing the mixture onto a moving belt; and polymerizing said encapsulating prepolymer to form a composite core material comprising mineral filler discontinuous portions disposed in a continuous encapsulating resin.