Abstract: A process for preparing water-absorbing polymer beads with high permeability by polymerizing droplets of a monomer solution, comprising monomers bearing acid groups, in a gas phase surrounding the droplets, wherein the monomer solution comprises polyvalent cations and the polymer beads have a mean diameter of at least 150 ?m.

Abstract: A process for continuously classifying water-absorbing polymer beads by means of at least one screen, at least one screen having at least one guide device on the screen surface.

Abstract: A process for preparing water-absorbing polymer beads with high permeability by polymerizing droplets of a monomer solution, comprising monomers bearing acid groups, in a gas phase surrounding the droplets, wherein the monomer solution comprises polyvalent cations and the polymer beads have a mean diameter of at least 150 ?m.

Abstract: A process for continuously preparing water-absorbing polymer beads, comprising the drying of a polymer gel on a forced-air belt dryer, the water content of the polymer gel being used to control the forced-air belt dryer during or after the drying.

Abstract: The present invention relates to a process for producing water-absorbent polymer particles by polymerizing droplets of a monomer solution in a surrounding heated gas phase and flowing the gas cocurrent through the polymerization chamber, wherein the temperature of the gas leaving the polymerization chamber is 130° C. or less, the gas velocity inside the polymerization chamber is at least 0.5 m/s, and the droplets are generated by using a droplet plate having a multitude of bores.

Abstract: A process for producing water-absorbing polymer particles by polymerizing droplets of a monomer solution in a surrounding gas phase in a reaction chamber, wherein the monomer solution is metered into the reaction chamber via at least one bore, and the diameter is from 210 to 290 ?m per bore and the metering rate is from 0.9 to 5 kg/h per bore.

Abstract: A process for producing water-absorbing polymer particles by polymerizing droplets of a monomer solution in a surrounding gas phase, wherein the polymer particles are coated with a permeability improver.

Abstract: A process for preparing water-absorbing polymer beads with high permeability by polymerizing droplets of a monomer solution in a gas phase surrounding the droplets, wherein a water-insoluble inorganic salt is suspended in the monomer solution and the polymer beads have a mean diameter of at least 150 ?m.

Abstract: A process for classifying water-absorbing polymer beads, wherein the polymer beads are separated into n particle size fractions by means of at least n screens and n is an integer greater than 1.

Abstract: The invention relates to the use of an apparatus for adding at least one solid or viscous liquid additive, or an additive dispersed in solvent, to a reactor interior of a reactor for preparing crosslinked, finely divided polymers by copolymerizing (a) water-soluble, monoethylenically unsaturated monomers and (b) from 0.001 to 5 mol %, based on the monomers (a), of monomers comprising at least two polymerizable groups, (c) from 0 to 20 mol %, based on the monomers (a), of water-insoluble monoethylenically unsaturated monomers, where the apparatus comprises at least one screw for conveying the at least one additive and the at least one screw ends in an addition orifice substantially flush with the inner wall of the reactor interior.

Abstract: A process for producing water-absorbing polymer particles, wherein an aqueous polymer gel is applied by means of a swivel belt to the conveyor belt of a forced-air belt drier, and the swivel belt, proceeding from one end position, is accelerated through a first pivot angle to an angular speed v1, decelerated through a second pivot angle to an angular speed v2 and decelerated through a third pivot angle to the other end position.

Abstract: A process for preparing water-absorbing polymer beads with high permeability by polymerizing droplets of a monomer solution in a gas phase surrounding the droplets, wherein a water-insoluble inorganic salt is suspended in the monomer solution and the polymer beads have a mean diameter of at least 150 ?m.

Abstract: A process for producing water-absorbing polymer particles by polymerizing droplets of a monomer solution in a surrounding gas phase in a reaction chamber, wherein the monomer solution is metered into the reaction chamber via at least one bore, and the diameter is from 210 to 290 ?m per bore and the metering rate is from 0.9 to 5 kg/h per bore.

Abstract: A process for continuously preparing water-absorbing polymer beads by determining at least one particulate delivery material mass flow by means of incident electromagnetic waves.

Abstract: A process for continuously preparing water-absorbing polymer beads, comprising the drying of a polymer gel on a forced-air belt dryer, the water content of the polymer gel being used to control the forced-air belt dryer during or after the drying.

Abstract: The present invention relates to a process for producing water-absorbent polymer particles by polymerizing droplets of a monomer solution in a surrounding heated gas phase and flowing the gas cocurrent through the polymerization chamber, wherein the temperature of the gas leaving the polymerization chamber is 130° C. or less, the gas velocity inside the polymerization chamber is at least 0.5 m/s, and the droplets are generated by using a droplet plate having a multitude of bores.

Abstract: A process for producing water-absorbing polymer particles by polymerizing droplets of a monomer solution in a surrounding gas phase in a reaction chamber, wherein the monomer solution is metered into the reaction chamber via at least one bore, and the diameter is from 210 to 290 ?m per bore and the metering rate is from 0.9 to 5 kg/h per bore.

Abstract: A process for producing water-absorbing polymer particles, wherein the water-absorbing polymer particles are surface postcrosslinked with unsaturated fatty acids or derivatives thereof.

Abstract: The present invention relates to a process for producing water-absorbent polymer particles by polymerizing droplets of a monomer solution in a surrounding heated gas phase and flowing the gas cocurrent through the polymerization chamber, wherein the temperature of the gas leaving the polymerization chamber is 130° C. or less, the gas velocity inside the polymerization chamber is at least 0.5 m/s, and the droplets are generated by using a droplet plate having a multitude of bores.

Abstract: The present invention relates to a process for producing water-absorbent polymer particles by polymerizing droplets of a monomer solution in a surrounding heated gas phase and flowing the gas cocurrent through the polymerization chamber, which comprises thermal postcrosslinking in the presence of steam.