ABSTRACT
Finely ground scrap polyurethane foam (Mobius Powdered Urethane, or M-PU) is used commercially in the production of new slabstock. The ability to reformulate to maintain density, hardness, and other properties is key to mechanical recycling. Here, we present results of recent flexible slabstock trials with powdered urethane, and relate them using simple mathematical models for the density, hardness, SAG factor, and maximum block temperature. The models can be used to add powdered urethane to new formulations, or to define practical limits for the use of recycled powder in foams, or to estimate the cost savings achieved by using powdered urethane.
Comfort factor (or SAG factor) is generally improved by the addition of powdered urethane. When foams are formulated to maintain density and 40% ILD, the increase in SAG factor is due to an increase in 65% ILD and a slight decrease in 25% ILD.
