Study of the internal temperature of rigid polyurethane bodies using temperature sensors

This paper investigates the effect of filling polystyrene foam beads (EPS) on the foaming temperature regulation of rigid polyurethane (RPUF) composites and describes the temperature change process of the first 400 s of the foaming reaction for two systems with high foaming temperature and low foaming RPUF. Different contents of expandable EPS were used to regulate the foaming temperature of RPUF to reduce the internal structural defects of the composite foam material caused by excessive internal foaming temperature which is effectively optimized for its use and low cost. RPUF with HCFC-141B as the physical blowing agent and expandable EPS as the filler were studied. MATLAB software was used to simulate the foaming process of pure RPUF for both systems and to predict the foaming temperature. The comparison with experimental data was made, and it was concluded that the foaming temperature of pure RPUF was too high. In addition, the temperature of the EPS-doped PUF porous composites in the core region and the temperature variation of the upper and lower surfaces during the foaming process were measured using a probe temperature sensor. The internal temperature is represented by a three-dimensional temperature trapezoid. The maximum temperature of the foaming process decreases more rapidly with increasing EPS content. In addition, the high RPUF heat loss and the smaller EPS growth energy lead to an increase in the mass fraction.