Patent Publication Number: US-2015069086-A1

Title: Automatic detergent dispensing device

Description:
This invention relates to an independent device suitable for dosing a detergent composition into a ware-washing machine. By independent, this means that the device is suitable for use inside any commercial ware-washing machine and operates independently of the control mechanisms of the ware washing machine. Alternatively the device may have the capacity for some interaction with the control systems of the ware washing machine. 
     This invention preferably relates to a device capable of using/dosing multiple detergent compositions, rinse aids, and other additives within one complete wash cycle of an automatic washing machine. The various cleaning compositions may be dosed into the machine at varying quantities, times, sequences, and for varying durations during a washing machine cycle. The use of multiple cleaning compositions allows for increased and optimized cleaning performance. 
     Preferably the device is suitable for use in an automatic dishwashing machine. 
     Current conventional systems used in automatic dishwashers only dose one detergent composition per wash cycle with the optional addition of a rinse agent composition at the very end of the washing machine cycle. The detergent compositions are primarily either enzymatic based or incorporate a hypohalite oxidative bleach (e.g. sodium hypochlorite, sodium dichloroisocyanurate, etc.). 
     Enzymatic detergents provide excellent cleaning on enzyme sensitive soils (primarily protein and starch based) but fail to provide performance on hard to remove stains, such as coffee, tea, and tomato stains. 
     Hypohalite based (for example, chlorine bleach based) detergents provide excellent cleaning on the hard to remove stains but fail to provide performance on the enzyme sensitive soils. 
     Because enzymes and hypohalite oxidizing bleaches are incompatible within the same formula matrix, the consumer must make a trade-off decision on performance and use one detergent composition or the other. This presents an obvious dilemma to the consumer—whether to get good cleaning on an enzymatic sensitive stain to the detriment of a hard to remove stain or vice versa. 
     The use of multiple detergent compositions within one washing machine cycle would mitigate this trade-off decision and provide optimal performance across the range of stains and soils normally encountered in an automatic dishwasher. However, given the incompatibility of enzyme based detergents and hypohalite detergents, the detergent compositions must be kept separate and dosed at different times so that the performance of each detergent is not affected by the presence of the other detergent. 
     In addition the separation of these ingredients also has a major benefit in terms of storage stability of the detergent composition. 
     One of the principle difficulties associated with automatic detergent dispensing devices is that of controlling the release of the detergent. 
     Release mechanisms are usually complicated and add significant cost to a device. With a multidosing device capable of releasing different ingredients separately, this problem multiplies as each agent requires a separate mechanism. Solid dispensing devices can become jammed as powders or solid detergent tabs swell from the ingress of humidity. Liquids require accurate measurement and separate pumping mechanisms. However liquids often increase the general detergent composition stability problems, both in terms of shelf storage and machine storage where they would be subject to multiple heat cycles. 
     It is an objective of the present invention to provide a simple, reliable and cost effective method of controlling the release of a treatment composition from a dispensing device. The method may be used with solid or liquid treatment compositions. It is preferable that each dose be separated from the other so that any humidity ingress would only effect a single dose and not all the dose present in the device. 
     At its most elemental the present invention comprises an independent automated detergent dosing device suitable for use in a ware-washing device. The device comprises at least one chamber that is sealed with a non-water soluble film; and wherein the at least one chamber contains a treatment composition and wherein the treatment composition is dosed by the controlled removal of the non-water soluble film from the at least one chamber such that the chamber is exposed to the wash liquor by direct ingress of the wash liquor to the chamber or via gravity. 
     In the present invention, the term “removed” or “removal” can mean the complete and total removal of the film from the chamber. Alternatively it can also mean only a partial removal of the film such that the treatment composition within the chamber can enter the wash liquor. This can be via gravity of by wash liquor ingress into the chamber through the partial removal of the film. 
     The removal of the film can be achieved by a variety of methods. A partial removal may happen by a simple piercing of the film with a blade or point, such that most of the film still remains in contact with the chamber while the treatment composition is exposed. 
     However it is preferred that the film is totally removed from the chamber. Once removed the chamber and its contents are completely exposed to the wash liquor. The method is simple and effective. The method is not prone to jamming or measurement inaccuracy. 
     It is a further object of the present invention is to provide a device capable of dispensing a plurality of treating compositions into a multistage automatic washing machine, the device comprising at least two chambers, each chamber containing a detergent or treating composition, wherein the detergent is released into the wash cycle by the removal of a film layer from the chamber, exposing the chamber to the wash liquor. 
     Each chamber encloses a three dimensional space of sufficient volume to contain a treatment composition. This may be between 1 and 100 cm 3 , more preferably between 2 and 50 cm 3 , more preferably between 3 and 20 cm 3  and most preferably between 5 and 10 cm 3 . 
     Each chamber has an outer surface that is preferably predominantly solid and immovable. This may be achieved by tensioning a flexible and deformable chamber. However each chamber has at least one external surface that comprises a removable thin non-water soluble film. 
     The chambers may have any three dimensional shape desired. They may be regular polygons or they may be irregular. They may be shaped to enable efficient packing within the device. 
     Preferably the chambers are combined together to form racks of the chambers. The chambers can be combined in any pattern. The racks may comprise linear lines of chambers for example. Or the racks may comprise a circular pattern of chambers. 
     The device may comprise one or more racks of chambers. Each rack may contain chambers comprising the same or different treatment compositions. 
     Preferably the device may comprise two or more racks of chambers, more preferably three or more racks of chambers and most preferably four or more racks of chambers. 
     The surface area of each chamber that comprises a removable film is preferably less than 50% of the total area, more preferably less than 40% of the total area more preferably less than 30% of the total area and most preferably less than 20% of the total area. 
     The chambers are preferably rectangular or square in profile. Preferably the removable film covers one face of the chamber or chambers. 
     Preferably the chambers have a height of between 0.2 and 5.0 cm, width of 0.2 and 5.0 cm and a length of 0.2 and 5.0 cm. More preferably the chambers have a height of between 0.5 and 1.5 cm, a width of between 1.0 and 3.0 cm and a length of between 2.0 and 4.0 cm. 
     Preferably the film is polymeric. 
     Non-limiting examples of suitable thin film materials are polyethylene, polypropylene and PET. The films may also have more than one layer and comprise more than one material. Potentially this may include metal foils. The skilled person will be aware of other suitable materials. 
     Preferably the thin film is between 5 μm and 500 μm thick, more preferably between 10 μm and 200 μm thick, more preferably between 25 μm and 150 μm thick and most preferably between 50 μm and 100 μm thick. 
     Preferably the device is responsive to external conditions and releases the contents of the chambers when optimal in the wash cycle. Alternatively the device may operate on a simple timing basis. 
     If the device is to be sensitive to wash conditions to release the treatment compositions, the device may comprise one or more sensors. 
     Alternatively the device may simply be heat sensitive and possess one or more bimetallic strips or a wax motor. 
     Preferably the device will comprise two or more sensors and most preferably three or more sensors. 
     The sensors may comprise a pH sensor, water sensor (including for example a conductivity sensor, total internal reflection or vibration sensor) turbidity sensor, temperature sensor, light sensor or combinations thereof. The invention is not limited to these sensor types. The skilled person may include other sensors. 
     The device may comprise basic computational capability to interpret the inputs from multiple sensors. This will allow the device to correctly interpret when to release the different components in the wash cycle. 
     Preferably the device has at least two different types of treatment compositions, more preferably at least three different treatment compositions and more preferably at least four different treatment compositions. 
     Each treatment composition may be held separately in its own dedicated refill rack. Or alternatively each rack may hold different treatment compositions. 
     A treatment composition for the purposes of the present invention means any chemical or enzymatic formulation suitable for use in a ware washing machine. The skilled person is aware of suitable formulations that may be used with the device of the present invention. 
    
    
     Examples of suitable treatment compositions are bleaching compositions, enzyme compositions, surfactant compositions, pre-treatment compositions, rinse aid compositions, water treatment compositions and combinations thereof. 
     Preferably the film is removed by the action of an electric motor and associated gearing. This may collect the film on a roller. The roller may be present on or in a refill rack. The removal may be partial or total. 
     It is preferred that the device will be powered by a battery. This is preferred for the advantages batteries provide in terms of high energy density, simplicity and low cost. 
     Alternative sources of energy for the device are
         Some form of capacitor (capacitor/super capacitor/ultra capacitor)   Heat from the automatic washing machine   Water flow from the automatic washing machine       

     Powering the device from heat from the machine or water flow from the machine provide environmental advantages as no separate power source is required from the device. It may then take all its energy needs from the machine. 
     In a preferred embodiment the device comprises four different treatment compositions. 
     Treatment Compositions 
     Preferably the treatment compositions are detergent compositions. 
     Any composition that is suitable for use in cleaning may be used in the device of the present invention. 
     The compositions may be in a solid form, liquid form gel form, paste form or gaseous form. The preferred form for the treatment compositions is solid. In the form of either powder or tablet. This is because a solid form provides the best stability for the many ingredients of the treatment compositions. 
     Non-limiting examples of treatment compositions that are suitable for use in the device of the present invention are given below. 
     Bleaching Composition. 
     Any type of bleaching compound conventionally used in dishwashing detergent compositions may be used according to the present invention. Preferably the bleaching compound is selected from inorganic peroxides or organic peracids, derivates thereof (including their salts) and mixtures thereof. Especially preferred inorganic peroxides are percarbonates, perborates and persulphates with their sodium and potassium salts being most preferred. Sodium percarbonate and sodium perborate are most preferred, especially sodium percarbonate. 
     Organic peracids include all organic peracids traditionally used as bleaches, including, for example, perbenzoic acid and peroxycarboxylic acids such as mono or diperoxyplphthalic acid, 2-octyldiperoxysuccinic acid, diperoxydodecanedicarboxylic acid, diperoxy-azelaic acid and imodoperoxycarboxylic acid and, optionally, the salts thereof. Especially preferred is phthalimidoperhexanoic acid (PAP). 
     The skilled person will be aware of other bleaching compositions that could be used with the present invention. 
     Bleach Activators 
     Suitable bleach activators such as TAED may be used in combination with the bleaching compound as desired. Bleach catalysts such Mn based compounds or salts may be used e.g. manganese acetate. The bleach activators may be in a separate treatment solution or may be combined in the same treatment composition as the bleach compound. 
     Rinse Aids 
     Preferably the cartridge chamber that is activated in the rinse segment contains a rinse agent. Suitable rinse aid components are: include surfactants such as those mentioned below, acids, such as citric acid and hydrotropes such as sodium cumene sulphate. 
     The skilled person will be aware of what formulations can be prepared that make effective rinse aids. 
     Water Softeners 
     Preferably the cartridge chamber that is activated in the treatment segment contains an anti-lime agent or a water treatment agent. Water softeners include phosphates and non phosphates such as MGDA, GLDA and citrate. 
     Anti Corrosion Agents 
     Preferred silver/copper anti-corrosion agents are benzotriazole (BTA) or bis-benzotriazole and substituted derivatives thereof. Other suitable agents are organic and/or inorganic redox-active substances and paraffin oil. Benzotriazole derivatives are those compounds in which the available substitution sites on the aromatic ring are partially or completely substituted. Suitable substituents are linear or branch-chain C 1-20  alkyl groups and hydroxyl, thio, phenyl or halogen such as fluorine, chlorine, bromine and iodine. A preferred substituted benzotriazole is tolyltriazole. 
     It is known to include a source of multivalent ions in detergent compositions, and in particular in automatic dishwashing compositions, for anti-corrosion benefits. For example, multivalent ions and especially zinc, bismuth and/or manganese ions have been included for their ability to inhibit such corrosion. Organic and inorganic redox-active substances which are known as suitable for use as silver/copper corrosion inhibitors are mentioned in WO 94/26860 and WO 94/26859. Suitable inorganic redox-active substances are, for example, metal salts and/or metal complexes chosen from the group consisting of zinc, manganese, titanium, zirconium, hafnium, vanadium, cobalt and cerium salts and/or complexes, the metals being in one of the oxidation states II, III, IV, V or VI. Particularly suitable metal salts and/or metal complexes are chosen from the group consisting of MnSO 4 , Mn(II) citrate, Mn(II) stearate, Mn(II) acetylacetonate, Mn(II) [1-hydroxyethane-1,1-diphosphonate], V 2 O 5 , V 2 O 4 , VO 2 , TiOSO 4 , K 2 TiF 6 , K 2 ZrF 6 , CoSO 4 , Co(NO 3 ) 2  and Ce(NO 3 ) 3 . Any suitable source of multivalent ions may be used, with the source preferably being chosen from sulphates, carbonates, acetates, gluconates and metal-protein compounds. Zinc salts are specially preferred glass corrosion inhibitors. 
     Enzymes 
     Any type of enzyme conventionally used in detergent compositions may be used according to the present invention. It is preferred that the enzyme is selected from proteases, lipases, amylases, cellulases, pectinases, laccases, catalases and all oxidases, with proteases and amylases, especially proteases being most preferred. It is most preferred that protease and/or amylase enzymes are included in the compositions according to the invention; such enzymes are especially effective for example in dishwashing detergent compositions. Any suitable species of these enzymes may be used as desired. 
     Surfactants 
     Surfactants can form key components of detergent compositions. There are four main classes of surfactants are anionic, cationic, amphoteric and non-ionic. 
     Non-ionic surfactants are preferred for automatic dishwashing (ADW) detergents since they are defined as low foaming surfactants. The standard non-ionic surfactant structure is based on a fatty alcohol with a carbon C 8  to C 20  chain, wherein the fatty alcohol has been ethoxylated or propoxylated. The degree of ethoxylation is described by the number of ethylene oxide units (EO), and the degree of propoxylation is described by the number of propylene oxide units (PO). 
     The length of the fatty alcohol and the degree of ethoxylation and/or propxylation determines if the surfactant structure has a melting point below room temperature or in other words if is a liquid or a solid at room temperature. 
     Surfactants may also comprise butylene oxide units (BO) as a result of butoxylation of the fatty alcohol. Preferably, this will be a mix with PO and EO units. The surfactant chain can be terminated with a butyl (Bu) moiety. 
     Preferred solid non-ionic surfactants are ethoxylated non-ionic surfactants prepared by the reaction of a mono-hydroxy alkanol or alkylphenol with 6 to 20 carbon atoms. Preferably the surfactants have at least 12 moles, particularly preferred at least 16 moles, and still more preferred at least 20 moles, such as at least 25 moles of ethylene oxide per mole of alcohol or alkylphenol. 
     Particularly preferred solid non-ionic surfactants are the non-ionics from a linear chain fatty alcohol with 16-20 carbon atoms and at least 12 moles, particularly preferred at least 16 and still more preferred at least 20 moles, of ethylene oxide per mole of alcohol. 
     The non-ionic surfactants additionally may comprise propylene oxide units in the molecule. Preferably these PO units constitute up to 25% by weight, preferably up to 20% by weight and still more preferably up to 15% by weight of the overall molecular weight of the non-ionic surfactant. 
     Surfactants which are ethoxylated mono-hydroxy alkanols or alkylphenols which additionally comprise poly-oxyethylene-polyoxypropylene block copolymer units may be used. The alcohol or alkylphenol portion of such surfactants constitutes more than 30%, preferably more than 50%, more preferably more than 70% by weight of the overall molecular weight of the non-ionic surfactant. 
     Another class of suitable non-ionic surfactants includes reverse block copolymers of polyoxyethylene and poly-oxypropylene and block copolymers of polyoxyethylene and polyoxypropylene initiated with trimethylolpropane. 
     Another preferred class of non-ionic surfactant can be described by the formula: 
       R 1 O[CH 2 CH(CH 3 )O] x  [CH 2 CH 2 O] y  [CH 2 CH(OH)R 2 ] 
     where R 1  represents a linear or branched chain aliphatic hydrocarbon group with 4-18 carbon atoms or mixtures thereof, R 2  represents a linear or branched chain aliphatic hydrocarbon rest with 2-26 carbon atoms or mixtures thereof, x is a value between 0.5 and 1.5 and y is a value of at least 15. 
     Another group of preferred non-ionic surfactants are the end-capped polyoxyalkylated non-ionics of formula: 
       R 1 O[CH 2 CH(R 3 )O] x [CH 2 ] k CH(OH)[CH 2 ] j OR 2    
     where R 1  and R 2  represent linear or branched chain, saturated or unsaturated, aliphatic or aromatic hydrocarbon groups with 1-30 carbon atoms, R 3  represents a hydrogen atom or a methyl, ethyl, n-propyl, iso-propyl, n-butyl, 2-butyl or 2-methyl-2-butyl group, x is a value between 1 and 30 and, k and j are values between 1 and 12, preferably between 1 and 5. When the value of x is &gt;2 each R 3  in the formula above can be different. R 1  and R 2  are preferably linear or branched chain, saturated or unsaturated, aliphatic or aromatic hydrocarbon groups with 6-22 carbon atoms, where group with 8 to 18 carbon atoms are particularly preferred. For the group R 3 ═H, methyl or ethyl are particularly preferred. Particularly preferred values for x are comprised between 1 and 20, preferably between 6 and 15. 
     As described above, in case x&gt; 2 , each R 3  in the formula can be different. For instance, when x=3, the group R 3  could be chosen to build ethylene oxide (R 3 =H) or propylene oxide (R 3 =methyl) units which can be used in every single order for instance (PO)(EO)(EO), (EO)(PO)(EO), (EO)(EO)(PO), (EO)(EO)(EO), (PO)(EO)(PO), (PO)(PO)(EO) and (PO)(PO)(PO). The value 3 for x is only an example and bigger values can be chosen whereby a higher number of variations of (EO) or (PO) units would arise. 
     Particularly preferred end-capped polyoxyalkylated alcohols of the above formula are those where k=1 and j=1 originating molecules of simplified formula: 
       R 1 O[CH 2 CH(R 3 )O] x CH 2 CH(OH)CH 2 OR 2    
     The use of mixtures of different nonionic surfactants is suitable in the context of the present invention for instance mixtures of alkoxylated alcohols and hydroxy group containing alkoxylated alcohols. 
     Other suitable surfactants are disclosed in WO 95/01416, to the contents of which express reference is hereby made. 
     In a particularly preferred embodiment of the present invention, the composition according to the first aspect of the present invention is one wherein the liquid non-ionic surfactant has the general formula 
       R 1 -[EO] n -[PO] m -[BO] p -Bu q    
     wherein: 
     R 1  is an alkyl group of between C 8  and C 20 ; 
     EO is ethylene oxide; 
     PO is propylene oxide; 
     BO is butylene oxide; 
     Bu is butylene 
     n and m are integers from 1 to 15; 
     p is an integer from 0 to 15; and 
     q is 0 or 1. 
     Examples of especially preferred nonionic surfactants are the Plurafac™ Lutensol™ and Pluronic™ range from BASF and Genapol™ series from Clariant. 
     The total amount of surfactants typically included in the detergent compositions is in amounts of up to 15% by weight, preferably of from 0.5% to 10% by weight and most preferably from 1% to 5% by weight 
     Preferably non-ionic surfactants are present in the compositions of the invention in an amount of from 0.1% to 5% by weight, more preferably 0.25% to 3% by weight and most preferably 0.5% to 2.5% by weight. 
     Each treatment composition is preferably held within multiple chambers. Preferably each type of composition is held within separate rack of chambers. A rack may be rigid or flexible. A rack may comprise a wide range of different materials. The rack may be injection moulded or thermoformed, for example. 
     A rack of chambers comprises a grouping of more than one chamber. Preferably the chambers within a rack share one or more external surfaces with the adjacent chamber or chambers. 
     Preferably the chambers are aligned and arranged in a linear fashion 
     Preferably the arrangement is such that a single thin film can form a continuous strip across all of the chambers in each rack. And that each chamber within each rack can be opened to the wash cycle consecutively. 
     Preferably the chambers have a recessed channel down each side to accommodate each side of the film. 
     Preferably each rack of chambers is also separately removable from the device. This may allow each type of composition to be independently refilled once all of the chambers have been exhausted. 
     Each rack may have a single type of treatment composition present in all the chambers or alternatively each rack may contain chambers with different treatment compositions. 
     The racks may have the same number of chambers or the racks may have a greater or smaller number of chambers. This will depends on the usage anticipated. 
     Preferably the racks of chambers will comprise between 2 and 30 chambers, more preferably between 5 and 20 chambers, more preferably between 8 and 15 chambers and most preferably between 10 and 12 chambers. 
     Additionally the size of the chambers may be different for different types of treatment composition. 
     Each rack of chambers may be described as a refill cartridge. Consumers may replace these independently when they are consumed. This allows for the fact that different treatment compositions may be exhausted at different rates. Racks containing formulations that will be used at the same rate may be fused together to be replaced in a single action. 
     As the device may be sensor controlled and react to conditions, the device may use more or one type of treatment composition than the others. This allows for the most efficient use of the chemistry. As only the expended compositions need to be replaced. 
     The film covered chambers will remain water tight through potentially multiple washing cycles. Only those chambers with their film removed will yield their treatment compositions to the wash cycle. 
     In one embodiment the rack of chambers is essentially a planar linear arrangement of chambers. These would be orientated so that a continuous length of sealing film will enclose all of the chambers. In use the film will be drawn down the rack, sequentially exposing more chambers. 
     In this embodiment the device would resemble a flat “plate” shape. Two electric motors may be required to control up to four different films (and therefore four different racks). Each motor may be geared to move two different films with forward and reverse motion. 
     In another embodiment the planar rack of chambers will be formed into the shape of a wheel. The outer circumference of the rack or wheel will comprise the continuous thin film. This will be drawn down in use, sequentially exposing more chambers. 
     In this embodiment there would still need to be two motors for the movement of up to four films. 
     In this embodiment the device would take the general shape of a cylinder.