Continuous Process for Recycling of Polyurethane Foam

Abstract

The investigation deals with the recycling of high resiliency polyurethane (PU) foam by the application of high-power ultrasound in a continuous ultrasonic reactor. The foam has been decrosslinked at various screw speeds and various amplitudes, then blended at different ratios with the virgin polyurethane rubber (PUR) and cured. The die pressure and the total power consumption have been recorded as a function of processing conditions. Rheological and mechanical properties, hardness as well as gel fraction and crosslink density of the decrosslinked foam and cured blends have been measured and compared in an attempt to find out the optimum condition for decrosslinking. Blends have also been prepared using different proportions of ground samples and virgin rubber, and a comparison of the properties between these blends and the blends of the decrosslinked foam has been carried out. The results show that compared to the ground samples, the blends of the decrosslinked samples are easier to mix and exhibit enhanced properties.