The present invention relates to a process for producing a Water-absorbing polymer structure based on acid group-containing monomers, comprising the process steps of:i) providing a monomer solution comprising the optionally partly neutralized, acid group-containing monomer;ii) mixing the monomer solution with fines which consist at least to an extent of 90% by weight, based on the total weight of the fines, of particles having a particle size of less than 850 μm, to obtain a monomer solution mixed with fines;wherein the mixing in process step ii) is effected in a mixer (1) in which a first stream (2) of the fines and at least one further stream (3) of the monomer solution are passed from different directions simultaneously to a rotating mixing tool (4).本發明係關於一種製造吸水性聚合物結構體之方法,該結構體係以含酸基團之單體為基質,該方法包含以下方法步驟:i) 提供一單體溶液,其係包含視需要經部分中和之含酸基團之單體;ii) 混合該單體溶液與粉體以獲得一混有粉體之單體溶液,該粉體之至少達90重量%係由粒徑小於850微米之顆粒構成,以該粉體之總重量計;其中該方法步驟ii)之混合係於一混合器(1)中施行,其中一第一粉體流(2)及至少一額外之單體溶液流(3)係由不同方向同時流至一旋轉混合工具(4)。