<p>The waste paper is dissolved in a pulper (1). Light fractions are separated out due to their ability to float in water. The separator device is a vessel (24) with a free water surface (25) and a mechanical device (26) for removing the light fractions from the water surface (25). In the inlet line of the vessel (24), a shutoff element (16, 20) can be inserted, by means of which the vessel (24) is periodically caused to overflow, whereby the light fractions floating on the water surface (25) can be flushed away. <IMAGE></p>
