| abstract |
In order to dry finely divided, expandable styrene polymers having a particle size of from 0.02 to 3 mm, the bead polymers, in the form of a slurry in water, are freed from the majority of the water and subsequently exposed to a gaseous medium. The drying is carried out in two steps, by jointly conveying the bead polymer and a first gas stream, warmed to from about 45 DEG to 120 DEG C., through a flow dryer, the ratio between the gas and the bead polymer being from 2 to 40 kg/kg, separating the bead polymer from the first gas stream, immediately transferring the bead polymer into a fluidized bed and treating the polymer with a second gas stream at from about 0 DEG to 75 DEG C. Styrene polymers obtained in this way are free-flowing and can be foamed without difficulty in commercially available prefoaming units. They are used, inter alia, in the construction industry, for example as aggregate for insulation plaster. |