Polyurethane casting inside a rotating drum is a controlled process that uses centrifugal force to shape and densify polymer components with high uniformity. Unlike static molds, rotation redistributes the reacting mixture radially, influencing wall thickness, bubble migration, and final mechanical properties. The process begins with two reactive liquid streams: a polyol blend and an isocyanate. When mixed, they undergo an exothermic polymerization to form polyurethane. This reactive mixture is introduced into a cylindrical mold mounted on a spinning axis. As rotational speed increases, centrifugal acceleration forces the liquid outward, coating the inner wall of the drum. Several physical effects dominate during this stage: * Density gradients drive entrapped gas bubbles inward toward the rotational axis, reducing voids in the final part. * Shear forces and viscosity evolution determine how evenly the material spreads before gelation. * Reaction kinetics (temperature-dependent) con...