Patent ID: 11866557
Assignee: HANWHA AZDEL, INC.
Field: Macromolecular chemistry, polymers (Chemistry)
Classification: CPC C | IPC C

Claim 6:
7. A method comprising:
producing a flame retardant thermoplastic fiber-reinforced porous core by combining reinforcing fibers, a first thermoplastic material and a compounded material comprising a flame retardant compounded with a second thermoplastic material, wherein the flame retardant thermoplastic fiber-reinforced porous core comprises a web formed from the reinforcing fibers held in place by the first thermoplastic material and the second thermoplastic material, wherein the compounded material comprises an antioxidant that turns from a first color to a second color upon exposure to an environment comprising oxidizing agent present at a first concentration, and wherein the antioxidant turns from the second color back to the first color upon exposure to an environment comprising oxidizing agent present at a second concentration lower than the first concentration, wherein the flame retardant thermoplastic fiber-reinforced porous core is stored in the environment comprising oxidizing agent present at or below the second concentration to maintain the flame retardant thermoplastic fiber-reinforced porous core at the first color; and
storing the produced flame retardant thermoplastic fiber-reinforced porous core layer in the environment comprising NOX present at the first concentration for at least 24 hours to turn the antioxidant in the flame retardant thermoplastic fiber-reinforced porous core from the first color to the second color.