| 摘要 |
<p>A process and an apparatus for the continuous production of laminated panels. Polyurethane components, catalysts and additives, comprising a low-boiling blowing agent, are mixed under pressure to keep the blowing agent in a liquid state; the resulting mixture is frothed by gradually releasing the blowing agent under pressure controlled conditions, through a lay-down device (19) having an elongated pressure equalization chamber (26) provided with a pressure-drop slot (29) which lead into a frothing cavity (30). The slot (29) comprises facing surfaces which extend in the flow direction to maintain a back pressure in the equalization chamber (26) to keep the blowing agent in a liquid state avoiding turbulent evaporation during the frothing. The frothing foam is thereafter delivered to form a layer having a substantial height, being continuously supplied between peripheral sheet materials (14, 16, 21; 24, 25) which are made to advance and between which the frothed polyurethane mixture complete its expansion performing a foamed reinforcing core (20). <IMAGE></p> |
