Abstract: A sieve plate of polymeric material for use in a distillation column, characterized in that said plate comprises:(a) a circular base portion provided with(i) a central axial aperture adapted to receive a shaft,(ii) an additional aperture capable of receiving a tubular member, and(iii) a plurality of perforations such that the perforations represent in total a free area of between 3 and 20%, the perforations having a uniform average diameter between 0.6 and 4.0 mm,(b) a flexible, flared-lip portion around the circumference of the base portion capable of sealing contact with the inner walls of a column, and(c) means for retaining the sieve plate on a shaft.