PURPOSE: To prefoam the titled resin particles without fusing of particles, with a high efficiency and uniformly, by pressurizing, heating the volatile foaming agent containing thermoplastic resin particles which are dispersed in a water in a pressure vessel under a specified condition, then discharging them in a low pressure zone through an orifice.
CONSTITUTION: The foamable thermoplastic resin particles 2 which contain a volatile foaming agent are dispersed in a water 3 by an agitating device 4 in a closed pressure vessel 1 and the space 5 within the vessel is pressurized with a pressurized air, etc. from a pressure holding valve 6 to the pressure higher than the vapor pressure of the foaming agent and heated by a heating device 7 to the temperature higher than the softening temperature of the resin. Then, a discharge valve 8 is opened. The mixture of the resin particle and the water is discharged to a discharge pipe 11 of an atmospheric pressure via a discharge conduit 9 and an orifice plate 10 and the prefoamed particle 12 is recovered in a net sack 13, etc. Desirably, the orifice has one or more open hole of 0.05W 300mm2.
MORI KIYOSHI
ANDOU MASAO
SENDA KENICHI
NISHIDA TATSUHIKO
| JPS561344A | 1981-01-09 | |||
| JPS58125729A | 1983-07-26 |
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