Frothed energy absorbing polyurethane materials and process of manufacture
OwnerWilliam Bruce Kemmler, John Bruce Applebyinventors
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Abstract
The present invention is directed towards a method of manufacturing frothed polyurethanes from raw materials that may best be described as quasi-prepolymer types where a partial prepolymer is reacted with a polyol. A partial pre-polymer, such as 4-4′-diphenylmethane diisocyanate, may be combined with a 4000 MW propylene-oxide based polyether polyol, such as polypropylene glycol which may be end-capped with a polyethylene glycol, or a 6000 MW propylene-oxide based polyether polyol, such as polypropylene glycol which may be end-capped with a polyethylene glycol, and a catalyst to produce frothed polyurethane material in sheet form having enhanced compressibility and elastic recovery.
Claims14
A frothed polyurethane composition consisting essentially of 35% to 65% by volume of a partial pre-polymer and 65% to 35% by volume of a propylene-oxide based polyether polyol in complimentary proportional percentage amounts exhibiting greater resiliency, energy absorption and force dissipation with materials of similar thicknesses, and of a substantially lighter weight and greater dimensional return elasticity.
A method for forming a frothed polyurethane composition exhibiting greater resiliency, energy absorption and force dissipation with materials of similar thicknesses, and of a substantially lighter weight and greater dimensional return elasticity comprising the steps of:
- a. blending in a high pressure mix head complimentary proportional percentage amounts of 35% to 65% by volume of a partial pre-polymer and 65% to 35% by volume of a propylene-oxide based polyether polyol;
- b. directing high pressure relatively inert gas at controlled volumetric flow rates into the mix head with the complimentary proportional percentage amounts of the partial pre-polymer and propylene-oxide based polyether polyol;
- c. dispersing the reactive mixture through a spray head creating a frothed polyurethane composition deposited onto a backing member or form at a predetermined thickness for curing,
- whereby the resulting composition has a molecular weight in the range between 4000 and 6000, a Shore Hardness in the range between 20A and 30A, and at least a 25% reduction in weight due to the frothing effect of the high pressure relatively inert gas.
Dependencies are inferred from the claim text.