| 摘要 |
The present invention relates to a method for producing expanded thermoplastic microspheres by heating. Unexpanded microspheres are dried under agitation to a dry solids content exceeding 98% by weight, preferably 99% by weight, before heating. The dried microspheres can be rewetted and then expanded by heating. The microspheres thus produced contain but minor amounts of agglomerates. The invention also comprises an apparatus for expanding the dried spheres. The apparatus has a belt conveyor (A), a device (B) for IR heating, a dosing device (C) for unexpanded spheres, and a collecting device (D) for expanded spheres. |
