Closed-loop recycled polyurethane foam, methods of manufacture and products therefrom
View Patent ↗The present disclosure relates to the production of molded products containing recycled content, and more particularly polyurethane foam which includes polyol recovered from chemical recycling of polyurethane foam scrap, which polyol has been treated to optimize viscosity and/or reactivity characteristics.
1. A method for closed-loop recycling of polyurethane foam scrap comprising:
forming a recycled polyol by subjecting polyurethane foam scrap to glycolysis, wherein said recycled polyol has an average equivalent weight in the range of 100-500 and wherein said recycled polyol has a viscosity range of 40,000 cps at 20° C. to 2,000 cps at 50 ° C.;
adding at least a portion of said recycled polyol to a virgin polyol to produce a polyol blend, wherein said virgin polyol has a viscosity range of 1,760 cps at 15° C. to 218 cps at 45° C.;
forming a polyurethane foam from said polyol blend;
producing said polyurethane foam scrap from said polyurethane foam;
wherein said polyol blend comprises 65-95 parts by weight of said virgin polyol, 5-25 parts by weight of said recycled polyol and a viscosity reducer comprising a dibasic ester wherein said dibasic ester is present at a level of 1-10 parts by weight of the polyol blend, wherein the viscosity reducer reduces the viscosity of the polyol blend to a range of 1,100 to 1,300 cps at 20° C.;
wherein said foam formation is characterized by a gel time of 220 seconds or longer and/or a rise time of 345 seconds or longer.
2. The method of claim 1 wherein said dibasic ester has a viscosity in the range of 1.0 to 5.0 cps at 20° C.
3. The method of claim 1 wherein a polymerization catalyst is added to said polyol blend, wherein said catalyst is present at a level of 0.1 to 1.0 part by weight of the polyol blend.
4. The method of claim 1 wherein said dibasic ester comprises a dimethyl ester of adipic, glutaric and/or succinic acid.