Process for continuous production of high density detergent agglomerates in a single mixer/densifier

Abstract

A process for preparing high density detergent agglomerates having a density of at least 650 g/l is provided. The process comprises the step of continuously mixing detergent granules having a density of less than about 450 g/l in a moderate speed mixer/densifier wherein the granules are pulverized and densified to produce agglomerates having a density of at least 650 g/l . The mean residence time of the granules in the moderate speed mixer/densifier is at least about 12 minutes, and preferably from 12 to 15 minutes. The process further includes the step of either spraying a binder or adding a coating agent in the mixer/densifier to facilitate agglomeration of the granules. Thereafter, the agglomerates are dried to obtain the high density granular detergent agglomerates which are ready for packaging as a low dosage detergent.

What is claimed is: 
     
       1. A process for preparing high density detergent agglomerates comprising the steps of: (a) continuously mixing detergent granules having a density of less than about 450 g/l in a moderate speed mixer/densifier wherein said granules are pulverized and densified to produce agglomerates having a density of at least 650 g/l, the mean residence time of said granules in said moderate speed mixer/densifier being at least about 12 minutes, said moderate speed mixer/densifier imparts from about 1×10 11  erg/kg to about 5×10 11  erg/kg at a rate of from about 1.4×10 8  erg/kg-sec to about 6.9×10 8  erg/kg-sec;   (b) spraying a binder in said moderate speed mixer/densifier to facilitate agglomeration of said granules; and   (c) drying said agglomerates to obtain said high density granular detergent agglomerates having a density of at least 650 g/l.   
     
     
       2. A process according to claim 1 wherein the mean residence time is in range from about 12 minutes to about 15 minutes. 
     
     
       3. A process according to claim 1 wherein the porosity of said granules is in a range from about 50% to about 70% and the porosity of said agglomerates is in a range from about 5% to about 20%. 
     
     
       4. A process according to claim 1 wherein said binder is water. 
     
     
       5. A process according to claim 1 wherein said binder is selected from the group consisting of water, anionic surfactants, nonionic surfactants, polyethylene glycol, polyacrylates, citric acid and mixtures thereof. 
     
     
       6. A process according to claim 1 wherein the operating temperature of said moderate speed mixer/densifier is in a range from about 30° C. to about 40° C. 
     
     
       7. A process according to claim 1 further comprising the step of adding a coating agent in said moderate speed mixer/densifier to enhance free flowability of said agglomerates. 
     
     
       8. A process according to claim 7 wherein said coating agent comprises less than about 6% by weight of said agglomerates. 
     
     
       9. A process according to claim 1 wherein said detergent granules enter said moderate speed mixer/densifier at a temperature in a range from about 20° C. to about 25° C. 
     
     
       10. A process according to claim 1 wherein said agglomerates have a mean particle size of from about 400 microns to about 700 microns. 
     
     
       11. A process according to claim 1 wherein said moderate speed mixer/densifier comprises a centrally mounted shaft carrying impact tools, said shaft rotating at a speed of from about 100 rpm to about 120 rpm. 
     
     
       12. A process according to claim 1 wherein said moderate speed mixer/densifier comprises a plurality of cutters, each of which rotating at a speed of about 3600 rpm.