Peroxide generating device and method

Abstract

The present invention provides a peroxide generating device for application in an automatic fabric washing machine, comprising an electrochemical cell for the production of peroxide from tap water and air, and a pH modifying device for the production of acidic and alkaline water. Thereby enabling washing of the fabric articles without the need for added chemicals and improved fabric care, due to the separate dosing of peroxide.

1 . An automatic fabric washing machine comprising: 
 (a) A peroxide generating cell comprising an electrochemical cell for the production of peroxide from tap water and air, and being suitable for use in said machine when the machine is in operation; and    (b) a pH modifying device comprising an electrochemical cell comprising one or more cathode and anode electrodes for the production of acidic and alkaline water; whereby no added chemicals are needed when the device is in operation.    
   
   
       2 . A washing machine according to  claim 1 , wherein the electrochemical cell, comprising an anode and a cathode made of carbon, conductive polymer, metal, alloys or combinations thereof.  
   
   
       3 . A washing machine according to  claim 1 , wherein the pH modifying device can be fed with tap water or softened water, and is able to split this water in an alkaline and an acidic water stream.  
   
   
       4 . A bleach generating process using the washing machine of  claim 1 , wherein a detergent composition comprising a bleach precursor is added to the washing machine when in operation.  
   
   
       5 . A bleach generating process according to  claim 4 , comprising the steps of: 
 (a) using at least part of the alkaline water stream from the pH modifying device for the generation of peracid bleach out of the peroxide and the bleach precursor, thereby increasing the pH of the washing liquor to between 9 and 13; and    (b) using at least part of the acidic water stream from the pH modifying device in the washing machine, thereby lowering the pH of the washing liquor of the washing process carried out therein, thereby lowering the pH to between 7 and 9;    
   
   
       6 . A bleach generating process according to  claim 5 , wherein the generation of peracid bleach takes place either in the washing machine drum or in an in-line or off-line mixing device.  
   
   
       7 . A bleach generating process according to  claim 6 , wherein the mixing device for generating the peracid is selected from the group consisting of a static mixer, dynamic mixer, stirred tank or storage tank or a combination thereof.  
   
   
       8 . A bleach generating process according to  claim 4 , wherein the bleach precursor is selected from the group consisting of sodium nonanoyloxybenzene sulphonate (SNOBS); nonanoyloxy aminocaproyloxy benzene sulphonate (NACOBS); sodium-4-benzoyloxy benzene sulphonate (SBOBS); N,N,N′N′-tetraacetyl ethylene diamine (TAED); sodium-1-methyl-2-benzoyloxy benzene-4-sulphonate; sodium-4-methyl-3-benzoloxy benzoate; 2-(N,N,N-trimethyl ammonium)ethyl sodium-4-sulphophenyl carbonate chloride (SPCC); trimethyl ammonium toluyloxy-benzene sulphonate; sodium 3,5,5-trimethyl hexanoyl-oxybenzene sulphonate (STHOBS); and substituted cationic nitrites; and mixtures thereof.  
   
   
       9 . A bleach generating process using the washing machine of  claim 1 , wherein a detergent composition comprising a bleach catalyst is used.  
   
   
       10 . A bleach generating process according to  claim 9 , wherein at least part of the alkaline water stream from the pH modifier is used for adjusting the pH of the washing liquor.  
   
   
       11 . A process according to  claim 4 , wherein part of the acidic water stream is used in a pre-washing process.  
   
   
       12 . A washing machine according to  claim 1 , wherein the washing machine further comprises a water softening device for the production of softened water from tap water, said softened water having less than 5° FH, whereby no added substances are used.  
   
   
       13 . A washing machine according to  claim 12 , wherein the water softening device comprises a flow-through capacitor comprising: 
 (a) ‘n’ plates comprising a conductive surface and chargeable in response to an applied DC potential, and    (b) ‘n−1’ non-conductive spacers to separate said plates from each other,    wherein n is a positive integer, n being at least 2.    
   
   
       14 . A bleach generating process using washing machine of  claim 12 , wherein the peroxide generating device is fed with softened water produced in the water softening device.  
   
   
       15 . A bleach generating process using washing machine of  claim 12 , wherein the pH modifier is fed with softened water produced in the water softening device.  
   
   
       16 . A laundering process for the cleaning of fabric articles wherein the bleach generating process of  claim 5  is used, characterised in that the pH of the bleach activating step (a) of said bleach generating process and the pH of step (b) of said bleach generating process are independently chosen.  
   
   
       17 . A laundering process according to  claim 16 , wherein a low environmental impact detergent product (LEIP) is used.  
   
   
       18 . A laundering process according to  claim 16 , wherein a dosing system is applied for automatically dosing the detergent composition.