A process for changing the morphology of a superabsorbent polymer gel (SAP polymer gel) with a single-screw extruder for changing the morphology of superabsorbent polymer gel (SAP polymer gel), having: - an input aperture for the introduction of SAP polymer gel, - connected to the input aperture, a channel, - arranged in the channel, a screw for conveying, and changing the morphology of, the SAP polymer gel and - connected to the channel, an output aperture for the discharge of the SAP polymer gel with changed morphology, where the screw has a shank and has screw flights arranged on the shank and is arranged and configured to convey the SAP polymer gel from the input aperture to the output aperture by means of the screw flights, where the channel has an input zone arranged at, or in the vicinity of, the input aperture, an output zone arranged at, or in the vicinity of, the output aperture, and a conveying zone extending along the channel from the input zone to the output zone, wherein - the screw has a first pitch value of a pitch of the screw flights along the conveying zone of the channel and, following in conveying direction, has a second pitch value of the pitch of the screw flights along the conveying zone of the channel, and where the second pitch value is smaller than the first pitch value, and - a shank diameter (d) of the shank of the screw increases along the channel, where the process has the following steps: - introduction of the SAP polymer gel from a polymerization process into the single-screw extruder, - operation of the single-screw extruder in order to change the morphology of the SAP polymer gel, and - discharge of the SAP polymer gel with changed morphology from the single-screw extruder to a drying process. - an input aperture for the introduction of SAP polymer gel, - connected to the input aperture, a channel, - arranged in the channel, a screw for conveying, and changing the morphology of, the SAP polymer gel and - connected to the channel, an output aperture for the discharge of the SAP polymer gel with changed morphology, where the screw has a shank and has screw flights arranged on the shank and is arranged and configured to convey the SAP polymer gel from the input aperture to the output aperture by means of the screw flights, where the channel has an input zone arranged at, or in the vicinity of, the input aperture, an output zone arranged at, or in the vicinity of, the output aperture, and a conveying zone extending along the channel from the input zone to the output zone, wherein where the screw has a shank and has screw flights arranged on the shank and is arranged and configured to convey the SAP polymer gel from the input aperture to the output aperture by means of the screw flights, where the channel has an input zone arranged at, or in the vicinity of, the input aperture, an output zone arranged at, or in the vicinity of, the output aperture, and a conveying zone extending along the channel from the input zone to the output zone, wherein - the screw has a first pitch value of a pitch of the screw flights along the conveying zone of the channel and, following in conveying direction, has a second pitch value of the pitch of the screw flights along the conveying zone of the channel, and where the second pitch value is smaller than the first pitch value, and - a shank diameter (d) of the shank of the screw increases along the channel, where the process has the following steps: - introduction of the SAP polymer gel from a polymerization process into the single-screw extruder, - operation of the single-screw extruder in order to change the morphology of the SAP polymer gel, and - discharge of the SAP polymer gel with changed morphology from the single-screw extruder to a drying process. - introduction of the SAP polymer gel from a polymerization process into the single-screw extruder, - operation of the single-screw extruder in order to change the morphology of the SAP polymer gel, and - discharge of the SAP polymer gel with changed morphology from the single-screw extruder to a drying process.