Abstract: The invention relates to a continuous extrusion process for preparing cold water swelling phosphate-cross-linked starch derivatives, wherein the process consists of the subsequent steps of gelatinising an alkaline starch in a first zone (10) in the extruder; adding of POCl3 as cross-linking reagent in a second zone (11) in the extruder; cross-linking the obtained gelatinised starch by means of the POCl3 in the second and third zone (11, 12) in the extruder, and neutralising the obtained cross-linked gelatinised starch that is present in a fourth zone (13) in the extruder; recovering the obtained cross-linked, gelatinised starch in a fifth zone (14) in the extruder.

Abstract: The invention relates to a process for preparing a randomly-bonded polysaccharide, comprising as ingredients a saccharide, a polyol and an acid serving as a catalyst, the process comprising the steps of feeding the ingredients into a reactor in order to dehydrate the fed ingredients to an essentially anhydrous syrup, polycondensating the essentially anhydrous syrup at elevated temperatures in the said reactor while removing the reaction water, wherein the reactor is a mixing kneader device with counter-acting blades, wherein during the feeding step the saccharide, the polyol and the acid serving as catalyst are simultaneously or consecutively fed to the reactor, and in that during the dehydratation and polycondensation step the free water and reaction water is removed from the mixing kneader device by kneading and mixing the fed ingredients and the subsequent essentially anhydrous syrup under reduced pressure in the reactor, and during the polycondensation the essentially anhydrous syrup is continuously knead