Process for reducing the VOC content of a polyolefin composition

Abstract

The present invention relates to a process for reducing the volatile organic compound (VOC, VDA 278 October 2011) content of a polyolefin composition, the polyolefin composition including a polypropylene homopolymer, a polypropylene copolymer, a polyethylene homopolymer, and/or a polyethylene copolymer, the process comprising the steps of a) subjecting the polyolefin composition having a VOC (VOC, VDA 278 October 2011) content, which is contained in an aeration vessel, to an aeration gas flow, and maintaining said aeration gas flow for an aeration time of 15 hours or less the aeration gas having a minimum temperature of at least 20° C. measured at an inlet of the aeration gas of the aeration vessel, and a maximum temperature of 99° C. measured at an inlet for aeration gas of the aeration vessel; the aeration vessel having—at least one inlet for aeration gas,—at least one outlet for aeration gas,—an inlet for the polyolefin composition having a VOC content,—an outlet for an aerated polyolefin composition at the bottom of the aeration vessel; wherein the polyolefin composition contains 20 to 55 pieces/g (pellet size 3-5 mm) as measured according to the specification; and wherein the polyolefin composition is present in the aeration vessel as a packed bed; and b) withdrawing the aerated polyolefin composition from the aeration vessel having a VOC content (VOC, VDA 278 October 2011) of not greater than 600 μg/g.

Dependencies are inferred from the claim text.