Patent ID: 8304518

Claim:
Method for thermal treatment of polyester pellets, to obtain a partial crystallization, the method comprising the steps of: (a) feeding polyester melt to an underwater granulation system and granulating the melt to obtain pellets; (b) transporting the pellets from the underwater granulation system to a water-solids separator to dry the pellets; (c) feeding the dried pellets to a crystallization reactor that is at least slightly inclined relative to a horizontal plane, the pellets having a temperature of greater than 100 degrees C.; and (d) transporting the pellets through the crystallization reactor to a discharge point, wherein the pellets travel through the crystallization reactor only by force of their own weight, the pellets having a temperature of greater than 130 degrees C. at the discharge point, wherein the increase in temperature is a result of the intrinsic heat present in the pellets and no external energy or heat is supplied.