Patent ID: 6458230
Filing Date: 2002-10-01
Classification: C08F,D04H,D06M

Abstract:
A method of recycling fibers and fiber bonding agent, comprising:a) preparing a bonding agent comprising an aqueous addition polymer dispersion having an addition polymer fraction which films at the temperature the aqueous dispersion is employed as a bonding agent, wherein the polymer contains acidic or basic functional groups which confer water-solubility to the polymer upon pH adjustment to either an acidic or basic aqueous medium; b) mixing fibers with the dispersion, thereby obtaining a fibrous composite product bound with the polymeric bonding agent of step a); c) subsequently, placing a quantity of the bonded fibrous material of step (b) in an aqueous solution adjusted to a pH which dissolves the polymer bonding agent of the fiber; and d) separating the polymer bonding agent free fibers from the bonding agent solubilized in the aqueous medium, thereby permitting reuse of the fibers independently in the preparation of another bonded fibrous composite material and the reuse of the polymer bonding agent by adjusting the aqueous solution to a pH at which the polymer exists as a dispersion in an aqueous medium, thereby placing the polymer in a redispersed form as a bonding agent for mixing with fibers to form another bonded fibrous composite material.