Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
2001-11-27
2003-12-30
Webb, Gregory E. (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
C510S221000, C510S424000, C222S103000, C222S105000
Reexamination Certificate
active
06670314
ABSTRACT:
TECHNICAL FIELD
The present invention is in the field of dishwashing, in particular it relates to dishwashing methods including methods for washing dishware/tableware in an automatic dishwashing machine using dishwashing products in unit dose and especially pouch form. The methods of the invention are especially useful for the removal of cooked-, baked- and burnt-on soils from cookware and tableware.
BACKGROUND OF THE INVENTION
Unitised doses of dishwashing detergents are found to be more attractive and convenient to some consumers because they avoid the need of the consumer to measure the product thereby giving rise to a more precise dosing and avoiding wasteful overdosing or underdosing. For this reason automatic dishwashing detergent products in tablet form have become very popular. Detergent products in pouch form are also known in the art.
It is normally the objective of the detergent formulator chemist to optimise the amount of actives delivered to the wash for a given unit cost. The amount of actives delivered to the wash is, among other factors, determined by the shape, size and density of the unitised dose form.
One of the drawbacks of unitised dose form such as tablets is that they have a fixed shape. The shape of dishwashing machine dispensers, on the other hand, is different from manufacturer to manufacturer. Tablets are designed to have a size and shape which fit all machine dispensers, this fact together with the mechanical properties of tablets usually constrains the amount of product composition which can be incorporated in the tablet. Similar considerations can also apply in the case of detergent products in pouch form.
Another drawback of detergent tablets is the fact that their manufacturing process requires the additional step of powder compaction. This slows down the dissolution rate of the ingredients forming the tablet, or requires the use of complex and expensive disintegrant systems, or makes it difficult to achieve differential dissolution of the detergent active ingredients.
Another factor that can contribute to the inefficient delivery of actives to the wash, in the case of tablets, is the need for adding carrier materials, as for example porous materials able to bind active liquid materials, binders and disintegrants. In particular, the incorporation of liquid surfactants to powder form detergent compositions can raise considerable processing difficulties and also the problem of poor dissolution through the formation of surfactant gel phases.
There is still the need for a unitised dose form which allows for optimum delivery of active components across different washing machine types and which provides improved processing and dissolution characteristics.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention, there is provided a method of washing dishware/tableware in an automatic dishwashing machine having a single or multi-compartment product dispenser which is normally closed and sealed after charging the machine and prior to delivery of the dishwashing product into the wash liquor and wherein the dishwashing product comprises one or more dishwashing compositions in a unit dose form. The unit dose forms used herein are deformable and preferably have a shape and size such that they are compressibly contained within the product dispenser. The dishwashing product has a deformability, as measured following the method described hereinbelow of greater than about 5%, preferably greater than about 8%, more preferably greater than about 10% and even more preferably greater than about 20%. The shape and size of the product are also such that it occupies at least about 60%, preferably at least about 70%, more preferably at least about 80%, especially more than about 85% of the volume of the corresponding compartment of the product dispenser in its closed state. Provided that in the case of single compartment dispensers the dishwashing product can occupy at least about 40%, preferably at least about 50% of the volume of the product dispenser compartment in its closed state. The term “compressibly contained” as used herein means that the product is in a state of compression within the closed product dispenser across at least one transverse section of the product. Preferably the product is in a state of compression across the smallest transverse section of the product in a direction generally perpendicular to the product dispenser closure means.
The deformability of the unit dose form may be measured using an Instrom materials tester (or similar) according to the following procedure. The unit dose form is placed on a flat surface such that it lies on a base of maximum footprint and a corresponding flat probe is brought down upon the upper surface of the unit dose form. The movement of the probe is continued until a sufficient reaction force is created to cause the unit dose form to fracture or burst. The deformability of the unit dose form may be defined as:
{
displacement
of
probe
after
touching
unit
dose
form
up
to
burst
point
total
unit
dose
form
thickness
}
×
100
The volume of the unit-dose containing product dispenser compartment in its closed state lies in the range from about 15 to about 70, preferably from about 18 to 50 and more preferably from about 20 to 30 ml. In the case of multi-compartment dispensers, the individual compartments generally have a volume of from about 10 to about 35 ml, preferably from about 15 to about 30 ml. The total volume of the product dispenser (both multi and single compartments) on the other hand is generally from about 20 to about 70 ml, preferably from about 30 to about 50 ml.
The deformability herein is measured when the unit dose form is resting on its maximum footprint. The deformability measured when the pouch is placed in this position is sometimes referred to herein as “vertical deformability”. The deformability measured when the unit dose form is rotated into a perpendicular plane is referred herein as “horizontal deformability”. In preferred embodiments the unit doses have differing vertical and horizontal deformability (so-called anisotropic deformability), the vertical and minimum horizontal deformability in the perpendicular plane preferably differing from each other by at least about 30% preferably at least about 40%. It is also preferred that the minimum horizontal deformability is greater than the vertical deformability. Anisotropic deformability is preferred herein from the dispenser fit, packaging and the feel and handling viewpoints.
The term “unit dose” herein refer to a dose of detergent product incorporating one or more dishwashing compositions and sufficient for a single wash cycle. Suitable unit dose forms include capsules, sachets and pouches which can have single or multiple compartments. Suitable unit dose forms for use herein include water-soluble, water-dispersible and water-permeable capsules, sachets and pouches. Preferred for use herein are water soluble pouches, based on partially hydrolysed polyvinyl alcohol as pouch material. Dishwashing compositions incorporated therein can be in liquid, gel, paste or pouch form, but preferably composition in liquid gel or paste form are substantially anhydrous for reasons of pouch stability.
In a preferred aspect of the invention, dishwashing product comprises a dose sufficient for a single wash cycle of an anhydrous dishwashing composition. The term anhydrous as used herein is intended to include compositions containing less than about 10% of water by weight of the composition, preferably less than about 5% of water and more preferably less than about 1%. The water can be present in the form of hydrated compounds, i.e. bound water or in the form of moisture. It is preferred that the composition contains less than about 1%, preferably less than about 0.1% free moisture. Free moisture can
Greener Simon John
Kinloch James Iain
Sharma Sanjeev
Smith David John
Bamber Jeffrey V.
The Procter & Gamble & Company
Webb Gregory E.
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