abstract |
Modified or filled rebond polyurethane foam structures having desired plushness and compression without adversely affected tensile strength at a given density as compared to unfilled rebond polyurethane foams are formed from an admixture of shredded or chopped polyurethane foam particles and a finely divided inorganic mineral filler, such as barium sulfate or calcium carbonate or mixtures of these and like mineral fillers, that is further mixed with a substantially non-foam forming liquid prepolymer binder that is free of surfactants in foam-stabilizing amounts. A portion of the polyurethane foam particles, from about 10 to about 60 parts by weight based upon 100 parts by weight, is replaced with filler. For each 100 parts by weight of the combined foam particles and filler, about 10 to about 30 parts by weight of prepolymer is added. After the wetted admixture is compressed to the required density, the prepolymer binder is cured with heat and/or steam. Surprisingly, the resultant filled rebond polyurethane foam structure is more plush and softer than unfilled rebond foam, and the filler is uniformly distributed throughout the cured binder and external to the foam cells of the foam particles. |