A process for increasing a granular particle density of a polymeric
product using at least one particle density promoting agent is described.
The process includes passing a gaseous stream comprising at least one
monomer through a fluidized bed reactor in the presence of a catalyst to
form a polymeric product having a first granular particle density of less
than or equal to about 850 kg/m.sup.3, contacting the polymeric product
with at least one particle density promoting agent to increase the
granular particle density of the polymeric product by at least 2%,
withdrawing the polymeric product having an increased granular particle
density and a recycle stream comprised of unreacted monomers, and cooling
and reintroducing the recycle stream into the fluidized bed reactor with
sufficient additional monomer to replace the monomer polymerized and
withdrawn as the polymeric product.