| 摘要 |
PURPOSE:To produce highly foamed particles uniformly in a short period, by carrying out the blowing of a heating medium when pre-foaming is effected in such a way that an internal pressure is exerted in a foaming tank. CONSTITUTION:Foamable polystyrene resin particles containing 8% of butane as a foaming agent are introduced from a hopper 3 into the foaming tank 1. A low pressure steam is blown into the foaming tank 1, a discharge vavle 64 is closed, the blowing of steam is continued with the foaming tank 1 closed, and the resin particles are foamed with the internal pressure of the foaming tank 1 retained at 0.01-0.05kg/cm<2>. When the top surface of the foamed particle layer reaches a first detector 81, the blowing of steam is stopped, the discharge valve 64 is opened, and then blowing of steam is resumed with the foaming tank 1 being open to the atmosphere, and when the top surface in the foaming tank reaches a second detector 82, the supply of steam is stopped and the foamed particles are obtained. |
