| 摘要 |
<p>PCT No. PCT/AT93/00073 Sec. 371 Date Aug. 19, 1994 Sec. 102(e) Date Aug. 19, 1994 PCT Filed Apr. 26, 1993 PCT Pub. No. WO93/22119 PCT Pub. Date Nov. 11, 1993In a process for recycling of gas-containing synthetic plastics material, this material at first is comminuted, molten, degased and filtered. The degased synthetic plastics material is supplied in the same plant before its solidification for gas introduction, and in order to homogenize the gas content, the gas amount introduced into the synthetic plastics material per time unit is controlled in dependence from the synthetic plastics material amount supplied per time unit to the gas introduction, and preferably the pressure of the synthetic plastics material to which gas is to be added, is kept almost constant. The apparatus suitable for performing this process comprises an extruder (12,13) for plasticizing and degasing the synthetic plastics material, the outlet (15) thereof is connected by means of at least one line (16) to a mixer (25), to which also a device (29) for supplying gas is connected. A melt pump (23) for the synthetic plastics material is inserted into the line (16) and the amount of melt delivered by this pump is used as a command variable for the gas supply, for which a device (29) is provided that is controlled by a control unit (22) proportional to the speed of the melt pump (23) (FIG. 1).</p> |
