Foaming method and foaming equipment for pre-foamed particles

The invention discloses a foaming method and foaming equipment for pre-foamed particles. The foaming method comprises the following steps: filling foamed particles with high-pressure gas to form the pre-foamed particles; the pre-foaming particles are put into hot water within 2-30 s, foaming is conducted for 15-40 s, then the particles are fished out, in the foaming process, the temperature of the hot water is kept to reach the temperature condition needed by foaming, and the foaming time is in direct proportion to the filling pressure of the high-pressure gas; and the foaming particles obtained after hot water foaming are subjected to pressure maintaining and drying. According to the invention, the pre-foamed particles are put into hot water for foaming within a certain time, the dissipation of filled high-pressure gas is prevented, in the foaming process, the temperature and pressure conditions of the hot water are maintained, the foaming time is controlled, and the pre-foamed particles are completely wrapp