Prodn. of high-density detergent granules

摘要

Prodn. of compacted granules for use in detergent compsns. is effected by prepg. a homogeneous premix contg. a olasticiser and/or lubricant, forcing the premix through a perforated die under a pressure of 25-200 bar, and cutting the extrudates into pieces corresp. to the predetermined granule size. The plasticiser and/or lubricant is an aq. surfactant paste and is added to the premix in an amt. of 0.5-10wt.%. The premix has a free H2O content of 4-8wt.%. The H2O content may be kept low by adding moisture-binding ingredients, esp. Na2SO4, Na2CO3 and/or zeolite, in anhydrous form. The premix is homogenised and extruded in a twin-screw extruder under a pressure of 80-180 bar. The cut extrudates are rounded (e.g., in a 'Marmurizer') while dusting with NaA zeolite, to produce granules with a dia. of 0.5-5 (esp. 0.8-3)mm. If necessary, the granules are dried in a fluidised-bed dryer at an air inlet temp. of up to 80 deg.C, corresp. to a granule temp. of 55-60 deg.C. Temp.-sensitive ingredients are added after drying, e.g., by spraying or as separate granules. The granules are used to prepare washing powders with a surfactant content of up to 35 (esp. 15-25)wt.%.