Spray-Drying Process

Abstract

A process for preparing a spray-dried detergent powder having (i) detersive surfactant; and (ii) other detergent ingredients; wherein the process comprises the steps of: (a) forming an aqueous detergent slurry in a mixer; (b) transferring the aqueous detergent slurry from the mixer through at least one pump to a spray nozzle; (c) contacting alkoxylated anionic detersive surfactant and/or acid precursor thereof to the aqueous detergent slurry after the mixer and before the spray nozzle to form a mixture; (d) spraying the mixture through the spray nozzle into a spray-drying tower; and (e) spray-drying the mixture to form a spray-dried powder.

1 . A process for preparing a spray-dried detergent powder comprising
 (i) detersive surfactant; and   (ii) other detergent ingredients;   wherein the process comprises the steps of:   (a) forming an aqueous detergent slurry in a mixer;   (b) transferring the aqueous detergent slurry from the mixer through at least one pump to a spray nozzle;   (c) contacting alkoxylated anionic detersive surfactant and/or acid precursor thereof to the aqueous detergent slurry after the mixer and before the spray nozzle to form a mixture;   (d) spraying the mixture through the spray nozzle into a spray-drying tower; and   (e) spray-drying the mixture to form a spray-dried powder.   
     
     
         2 . A process according to  claim 1 , wherein in step (c) the alkoxylated anionic detersive surfactant comprises alkyl ethoxylated sulphate and/or acid precursor thereof. 
     
     
         3 . A process according to  claim 1 , wherein in step (c) the alkoxylated anionic detersive surfactant comprises C 8-18  alkyl ethoxylated sulphate having an average degree of ethoxylation of from about 0.5 to about 3 and/or an acid precursor thereof. 
     
     
         4 . A process according to  claim 1 , wherein in step (c) the alkoxylated anionic detersive surfactant comprises acid precursor of an alkyl ethoxylated sulphate. 
     
     
         5 . A process according to  claim 1 , wherein in step (c) additionally sodium chloride is contacted to the aqueous detergent slurry after the mixer and before the spray nozzle. 
     
     
         6 . A process according to  claim 1 , wherein the aqueous detergent slurry comprises from about 0 wt % to about 5 wt % detersive surfactant. 
     
     
         7 . A process according to  claim 1 , wherein the spray-dried detergent powder comprises:
 (a) from about 0 wt % to about 10 wt % zeolite builder;   (b) from about 0 wt % to about 10 wt % phosphate builder; and   (c) optionally from about 0 wt % to about 15 wt % silicate salt.   
     
     
         8 . A process according to  claim 1 , wherein the aqueous detergent slurry formed in step (a) comprises from about 0 wt % to about 2 wt % alkoxylated anionic detersive surfactant. 
     
     
         9 . A process according to  claim 1 , wherein the spray-dried detergent powder comprises from about 8 wt % to about 20 wt % alkoxylated anionic detersive surfactant. 
     
     
         10 . A process according to  claim 1 , wherein in step (d) the mixture is at a temperature of from about 60° C. to about 130° C. when it is sprayed through the spray nozzle into a spray-drying tower. 
     
     
         11 . A process according to  claim 1 , wherein the mixture formed in step (c) comprises from about 20 wt % to about 35 wt % water. 
     
     
         12 . A process according to  claim 1 , wherein the spray-dried detergent powder is spray-dried laundry detergent powder. 
     
     
         13 . A process according to  claim 1 , wherein the spray-dried detergent powder comprises
 (a) from about 15 wt % to about 30 wt % detersive surfactant;   (b) from about 0 wt % to about 4 wt % zeolite builder;   (c) from about 0 wt % to about 4 wt % phosphate builder; and   (d) optionally from about 0 wt % to about 15 wt % silicate salt,   wherein in step (c) the alkoxylated anionic detersive surfactant comprises C 8-18  alkyl ethoxylated sulphate having an average degree of ethoxylation of from about 0.5 to about 3 and/or an acid precursor thereof.