High surface intermeshing profile reactor

Disclosed is a polycondensation reactor for polyesters, polyamides or polyarylates in which a low I.V. material is introduced into the reactor and a relative high I.V. polymer exists the reactor. The reactor has at least two overlapping cyclindrical interior chambers, each with a rotating shaft through its length. Each shaft has a plurality of stirrers and spacers designed to wipe all interior surfaces of the reactor. The stirrers can be shaped as a cycloid or involute profile, for example. Generally the stirrers on each shaft are indexed from one another preferably by 90 DEG and interdigitate with stirrers on the adjacent shaft. Stirring the low I.V. material by rotating the stirrers (on the shafts) through the material spreads it into a plurality of thin films. At the temperature and vacuum conditions of the reactor, a volatile component is removed, thus causing the material to polymerize, by condensation, forming a relatively high I.V. polymer.