| 摘要 |
Expanded thermoplastic microspheres are produced by heating unexpanded microspheres after they have been dried under agitation to a dry solids content exceeding 98 wt.%, pref. 99 wt.%. The microspheres, once dried, can be rewetted before expansion. - The dried unexpanded microspheres are pref. expanded by heating them using a number of overhead IR lamps located above a belt conveyor having an endless belt on which they are delivered by a dosing device comprising a dosing screw and a vibrating feeder. |
