Multi-Dosing Detergent Delivery Device

Abstract

The invention concerns a multi-dosing detergent delivery device that is removably insertable into an automatic dishwashing machine. The device comprises a cartridge capable of receiving therein a rack of dosage elements of a cleaning composition, a collection area formed in a lid area of said device suitable to collect water/wash liquor in a main wash cycle of a dishwasher and a directing means to direct water or wash liquor from said collection area selectively to an interior part of said device. In particular, the device of the present invention includes a sieve arrangement located in the lid area to prevent or impede particles from blocking water/wash liquor flow into said interior part of the device.

Description

This invention relates to a multi-dosing detergent delivery device containing a plurality of dosage elements of cleaning composition, for use in a ware washing machine, for example a dishwashing machine or a laundry washing machine.

In multi-dosing detergent delivery devices it is necessary to selectively feed a compartmentalized cartridge with water and thereby provide a directed water flow into a single compartment. This feeding system is susceptible of clogging and needs to be free of blockages for optimal water flow.

In European dishwashers a sophisticated water filtering system is takes care of food soil and lumps coming from soiled dishware. However, food soil can still enter the system while the consumer is handling soiled dishes when placing them in the rack of the dishwasher and in some cases the filtering system of the dishwasher is not efficient enough.

In dishwashers commonly in use in North America, this issue is even more severe. The dishwasher filtering system is generally much less efficient and therefore food particles stay for prolonged times in the washing liquor. The food particles are also pumped around in the dishwasher and can reach the water feeding system of the device. This leads in every second to third run to complete blockage of the feeding system and as a result to no or incomplete dissolution of the detergent in the main wash cycle of the dishwasher.

Attempting to solve the problems of ensuring proper dissolution of the cleaning composition within a given time frame in a dishwasher environment, is not a trivial exercise as dishwasher design varies around the world, and filtration systems in use in dishwashers show such variation.

Accordingly, it is an aim of preferred embodiments of the invention to provide a multi-dosing delivery cartridge capable of overcoming, or minimising the above mentioned problems and providing good resistance to blockages regardless of dishwasher type or placement of the device within any given dishwasher.

According to a first aspect of the invention, there is provided a multi-dosing detergent delivery device removably insertable into an automatic dishwashing machine, the device comprising a cartridge capable of receiving therein a rack of dosage elements of a cleaning composition, a collection area formed in a lid area of said device suitable to collect water/wash liquor in a main wash cycle of a dishwasher, a directing means to direct water or wash liquor from said collection area selectively to an interior part of said device, wherein the device further includes a sieve to prevent or impede particles from blocking water/wash liquor flow into said interior part of the device.

Preferably, said sieve is located in a lid area of said device and, most preferably, extends across substantially a full available water collection area of said lid.

Preferably, said sieve comprises a non-hydrophobic material.

Preferably, said sieve comprises a non-plastics material.

Preferably, said sieve comprises a stainless steel mesh.

Preferably, said mesh has a mesh size between 3.5 mm and 0.2 mm, most preferably between 1 mm and 0.4 mm.

In a preferred embodiment, said sieve comprises market grade, plain square weave, 304 stainless steel. Said mesh may have a preferred aperture size of 0.4 to 0.42 mm and be made from wire having a diameter in the range of 0.2 to 0.24.

Preferably, said device is a cylindrical device having a diameter of approximately 8 cm.

Preferably each dosage element is of elongate formation and is housed within a chamber having at least one opening for receiving sieved water/wash liquor from said directing means.

Preferably, the rack is in the form of a parallel array of elongate chambers, each containing a solid dosage element. Preferably, the nested form is generally cylindrical for easy placement within the device.

Preferably, each dosage element contains between 15 and 25 g of cleaning composition.

Preferably, each chamber comprises a sleeve, for example of a plastics material. Alternatively any other suitable material may be used, such as, cardboard-based material (especially covered by a water-resistant material). Laminated cardboard with a suitable laminate is one material which may be used. Each sleeve may have at least one opening to allow the dosage element to be washed away in use. Preferably each sleeve has two openings, at opposite ends so that water may enter one end (the upper end in use) and leave the other end (the lower end in use), carrying with it dissolved or broken away cleaning composition. An upper opening may suitably be of area at least 10 mm², preferably at least 30 mm², and most preferably at least 60 mm². Suitably it may be of area up to 200 mm², preferably up to 160 mm², and most preferably up to 120 mm². The upper face of the sleeve may suitably be left totally open. A lower opening may suitably be of area at least 3 mm², preferably at least 6 mm², and most preferably at least 10 mm². Suitably it may be of area up to 200 mm², preferably up to 60 mm², and most preferably up to 20 mm². The lower face of the sleeve is preferably not left totally open, so that it retains the dosage element in place, until in use it dissolves. There may be one or more intermediate openings in the side face of the sleeve, i.e. between the upper opening and the lower opening, and the size thereof preferably conforms to the definitions given above for the lower opening.

Preferably the sleeves are formed in one piece. That piece may be in the form of a moulded or thermoformed tray having multiple compartments, into which the dosage elements are placed. The backing material may be secured over the tray to entrap the dosage elements. In such an embodiment the tray and backing material together form the sleeves. Alternatively, the backing material may be on the inside of the sleeves so that the dosage elements project outwards therefrom e.g. a central core of backing material with sleeves containing backing material projecting radially outwards.

The dosage elements are of a solid cleaning composition and as such may be of a particulate material, for example powder or granules, provided that the material is retained until it is washed away in use; for example in a sleeve as described above. Preferably however the dosage elements are of a solid cleaning composition in the sense of being non-flowable. Preferably they are of a coherent mass; preferably formed by a moulding or shaping process, for example injection moulding, extrusion, casting or compression forming. In a particular embodiment of the invention the solid cleaning composition may be a viscous gel or paste provided that it is sufficiently viscous so as to be non-flowable.

Preferably the dosage elements are identical to each other.

Preferably the dosage elements are of substantially the same cross-section along their length; in particular, they preferably do not taper.

Preferably the rack is such that, in its nested form, each pair of dosage elements is separated by a spacing, at least for part of the depth of the dosage elements. The spacing preferably extends part-way towards the backing; for example between one-third and two-thirds of the distance to the backing. The device cartridge into which the nested rack is placed, in use, preferably has an array of walls radiating from a hub, wherein spacings must be mated with divider walls when the article is located in the device cartridge. There could be one-to-one correspondence between spacings and divider walls, but preferably there are more spacings than divider walls. Three or four divider walls will generally suffice to cause the nested rack to be located correctly in the device cartridge. In general we may say there are preferably 3-8 divider walls, preferably 4-6.

The multi-dosing detergent delivery device is generally a plastics body, rigid and substantial, but the nested rack, once the dosage elements have gone, is light and may even be rather flimsy. It suitably comprises just the backing material and the sleeves (which may be light thermoformed sheet, or film). The rack is intended as a refill, whilst the remainder of the multi-dosing delivery device, comprising cartridge, collection area and directing means, is retained. The wastage of material when the rack of dosage elements is exhausted is very small. The invention may thus be seen as a desirably ergonomic solution.

Preferably the device has means to deliver water to the rack of dosage elements in sequence, one in each wash. Such means may operate automatically or be operated by the user, before a wash is commenced.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 shows a rack of dosage elements for use with a multi-dosing detergent delivery device of the present invention in a nested form, in a perspective view, generally from above;

FIG. 2 shows the article of FIG. 1 in nested form, in side view;

FIG. 3 shows the article of FIG. 1 in flat form;

FIG. 4 shows the dosage element of FIG. 3 in plan view;

FIG. 5 a shows the article of FIG. 1 being introduced into a multi-dosing detergent delivery device of FIG. 5b, the cap, containing the dosage element selecting device, being shown removed, as FIG. 5c;

FIG. 6 shows the article of FIG. 1 having been located within the holder of FIG. 5b; and

FIG. 7 shows the fully assembled device, with the cap of FIG. 5c having been placed on the holder and article assembly of FIG. 6a.

The rack of dosage elements of FIG. 1 is manufactured as a flat plastics tray of elongated blister pockets 2, shown in FIG. 3, comprising a thermoformed plastics tray. The open end of each blister pocket 2 is formed all around its perimeter with an endless flange 4 (which can be seen in FIG. 2). Solid rods or sticks of a cleaning composition 6 (intended in this embodiment to be used for cleaning in an automatic dishwasher machine) are introduced into the blister pockets. This can be done in different ways. For example in one embodiment the cleaning composition can be injected or cast into the pockets. However in this embodiment the rods or sticks are pre-formed by injection moulding or extrusion, then cut to length, then introduced into the pockets. It may be noted that they are introduced into the pockets to fill each pocket to the bottom end 8, but to leave a space 10 at the top end. This space 10 is left so that water can enter the pocket, via opening 12 in the upper end wall of the pocket and, as is discussed later, may also help in providing complete dissolution of cleaning composition within a reduced time period. In this embodiment each such opening 12 is circular, and 8 mm in diameter. An identical opening (not shown) is formed in the lower end wall of the article, to allow water and entrained or dissolved cleaning composition to exit the pocket.

Once all of the pockets have been provided with the rods or sticks of cleaning composition (by whatever means) a backing sheet 14 is laid over the open ends, and secured to the flanges 4. The backing may be adhered thereto by any convenient means, for example by heat or adhesive.

Next, the flat article, now in the form of a rack or linear array of rods or sticks, may be curled into its nested form shown in FIG. 1. In this embodiment the nested form is a generally cylindrical array. It may be retained in its nested form by a piece of adhesive tape 16.

The backing may be printed on its outwards-facing side with information, for example a trade mark, with product get-up, and/or with usage information.

As shown in FIG. 4, each rod or stick—and correspondingly each blister, has a flat base wall 18 abutting the backing sheet 14. From the base wall 18, each rod or stick, and each blister, generally tapers to a narrower distal end wall 20. The side walls initially taper gradually, as at 22, 24, then undergo a somewhat abrupt inward dislocation 26, then taper at an intermediate rate (between that of the side wall portion 22 and the dislocation 26) at 27, until the distal end wall 20 is reached.

The rods or sticks may be regarded as having the general shape of a triangular prism (i.e. trigonal). To be more precise, as noted above the side walls taper in a discontinuous manner.

It will be noted that the rods or sticks are located on the backing sheet with a separation 28 between them, at their base walls 18.

It may further be noted that the rods or sticks have a separation 30 between them, at their distal end region, when in their nested form.

The backing sheet has, as a result of the mould into which it is thermoformed during manufacture, preferential fold lines 32. These fold lines 32 are aligned with the spacings 28 between the rods or sticks.

The end result of these features is as follows, and can be clearly seen in FIG. 1: when the article is formed into its nested shape the backing sheet is displaced about its fold lines 22, in an articulated manner. This nesting or folding is permitted by the spacings 28 and 30; if the sticks or rods simply abutted against each other the operation would not be permitted, due to physical obstruction. As can be seen in FIG. 1 the spacings 30 in the distal end regions may remain even in the nested form (though obviously narrowed).

In use, the rack of dosage elements is a refill which is supplied in its nested form shown in FIG. 1, and also FIG. 5a. In that nested form it is inserted into a holder, shown in FIG. 5b. The holder is a cylindrical tub having a hub-like axial projection 40 extending upwards from its base substantially the whole axial length of the tub. Projecting outwardly from the projection 40 are four fins 42, set at 90° intervals. The fins extend approximately four-tenths of the radial distance of the holder.

The holder has a hanging handle 44.

The bottom wall of the holder is a large opening (not shown).

The holder has a lid shown in FIG. 5c. The lid defines a water/wash liquor collection area which extends across substantially a full upper surface area of the lid (in other words, across substantially the full cross-sectional area of the cylindrical device) and has a central indexing device 46 surrounded by a sieve 48, to allow particulate-free water to enter the holder. The central indexing device has a push button 50 and, around it, a dial 54 carrying numbers, equalling the number of rods or sticks of cleaning composition. Each time the dishwasher is to be used, the user presses the button to advance the control dial by one number, bringing the next rod or stick of cleaning into use. This is done by rotating an apertured disc within the lid by one position so that water entering the holder is directed via directing means comprising the aperture thereof, now in alignment with the next rod or stick. Water enters the appropriate blister through the opening 12 which is aligned with the opening within the lid. The water may fill the spacing 10 above the rod or stick. The rod or stick is soaked by the water and dissolves and/or crumbles away, leaving the blister through the bottom opening.

In cleaning performance tests of the device a specific number of soiled dishes with specific soils are used. In the tests, it was found that there is a “bottle neck” within the device that limits water flow, this bottle-neck being equivalent to a constriction provided by a hole having the dimensions of approximately 3 mm×4 mm. In a tests featuring a North American design of dishwasher in every second wash the bottle neck would, in the absence of a sieving system become completely blocked mainly by minced meat soil.

By including a sieve 48 within the device, the following results were achieved.

Plastic sieves were initially used (made out of Polypropylene or Polyethylene) however, these were surprisingly only found to be effective in terms of providing sufficient water/wash liquor flow with very large mesh sizes (4 mm in diameter or more). Such a large size is required because plastics material has hydrophobic features leading to air bubble formation and a relatively high observed surface tension/contact angle of the water on plastic which, on smaller meshes limits water/wash liquor flow severely. Unfortunately however whilst a large mesh size will allow sufficient clean water flow, the mesh size is so large that it does not provide any effective filtration to filter efficiently soil from the washing liquor.

Surprisingly, metallic mesh sieves have been found to be particularly effective. Stainless steel mesh sieves with various mesh sizes have been tested. Up to a mesh-size of 0.3 mm aperture water can pass through. Stainless steel sieves of a certain mesh size can efficiently filter the washing liquor entering the device and on the other hand do not reduce the water flow to an unacceptable level (not more than 35% reduction in water flow) and, indeed, can help to remove the bottleneck from the interior of the device and smooth overall flow.

Particularly preferred sieve meshes have been found to be stainless steel sieves with a mesh size between 3.5 mm and 0.2 mm apertures , and most preferably between 0.4 to 1 mm aperture for the efficient filtering of food soil without reducing the water flow significantly. In preferred embodiments of the invention, the sieve utilised is known as market grade, plain square weave, 304 stainless steel having a mesh size of 0.415 mm and made from 0.22 mm diameter wire.

In devices in accordance with the invention, somewhat surprisingly, we have found that excellent dissolution of the rods or sticks is achieved. It might have been expected that dissolving dosage elements of the cleaning composition by directing water to one end of them in an axial or lengthwise direction might be an inefficient method. In fact, dissolution or dispersion is excellent and the arrangement is very space-efficient, in not taking up very much of the “footprint area” available within the dishwashing machine.

In determining the minimum footprint of the device, a number of factors are involved. Firstly, it is generally the case that for an efficient cleaning cycle to be carried out by a dishwasher a dosage element should contain between 15 and 25 g of cleaning composition. For efficient working within the device of the present invention, an average density of the composition is set within the range of 1.0 to 1.5 g/cm³ and the preferred hardness of the composition is between 100N-400N.

In arriving at required dimensions for the device, dishwasher environments were analyzed for flow of water/wash liquor and it was found that, in general, water flow rates within a dishwasher are in the range of 1 g of water to 15 g of water per square centimetre per minute.

Tests have shown that standard dishwashing cleaning compositions (detergents) show a complete dissolution after 5 to 20 minutes in a standard dissolution test comprising complete immersion of detergent in water, at 40° C., under mechanical action.

Where a cleaning composition having a 10 minute standard dissolution time is utilised, a minimal water flow of 200 g of water per minute is required through a chamber, whereas for a 20 minute standard dissolution time cleaning composition, a 500 g per minute water flow has been found to be required. Preferably the device of the present invention utilises a cleaning composition having a standard dissolution time of 5 minutes.

It has been found that a device which can collect and direct by any means a minimum of 50 g of water per minute into a chamber is able to dissolve a cleaning composition having a standard dissolution time of 5 minutes therein in a 50° C. normal programme.

It is desirable for the device to function when placed anywhere within a the dishwasher in which a minimum amount of water is available to it, and so it has been assumed that perhaps only 1 g water per minute per square cm is available. With this in mind, to assure that said water collection area is sufficient to provide 50 g of water per minute, a water collection area of 50 cm2 is desirable, meaning a cylindrical device will require a diameter of approximately 8 cm2. Whilst the foregoing may be the optimum dimensions for the device, it will be appreciated that the present invention may be seen to cover a range of devices with differing dimensions with, for instance, water collection areas in the range of 30 cm2 to 80 cm2 and that where high flow rates of water/wash liquor are known to be present a device, having reduced dimensions may be utilised. Most preferably, the ratio of said water collection area to cleaning composition standard dissolution time is within the range of 5 to 50 and, particularly in the range of 10 to 30.

Where we refer to standard dissolution times, what is meant is the time to take for the cleaning composition to be substantially completely disintegrated in a given test environment. In such a test dosage elements are provided in separate metal cages and mechanically agitated in 40° C. water. The dosage elements are, in fact, not completely dissolved as such as they contain some water insoluble ingredients, therefore we can not speak about complete dissolution but “standard dissolution” which equates here to complete disintegration.

It has surprisingly been found that the dissolution of cleaning composition within the device is aided when each dosage element is housed within a chamber having a larger volume than the cleaning composition stored within it—hence the spacing 10 above the rod or stick—and it may also be desirable to provide a spacing between a lowermost part of the cleaning composition stick and the bottom of its respective outer sleeve. Dissolution is particularly improved when the volume of the chamber does not exceed the volume of the dosage element by more than 40% and most preferably when the volume of the chamber exceeds the volume of the dosage element by between 15 and 20%.

As can be seen in FIG. 6a, when the article is located within the tub of the holder the fins 42 are located within spacings 30 of the nested article. The tolerance of the fins in the spacings 30 is not large and in this way it is assured, that the rods or sticks, and the upper openings 12, are in the correct orientation, to align with the opening within the lid.

FIG. 7 shows the fully assembled device.

As will be apparent to the skilled man, many variations may be made to the device without departing from the scope of the present invention. For instance, whilst the sieve 48 is shown in FIG. 5(c) is located within a central water collection area of the lid 46 surrounding the push button 50, it can be utilised advantageously in different types of device, for instance devices having automatic indexing systems driven by, for instance a wax motor. In such cases, the mesh may advantageously extend over a full top surface area of a lid of the device.

Claims

1. A multi-dosing detergent delivery device removably adapted to be insertable into an automatic dishwashing machine, the device comprising a cartridge adapted for receiving therein a rack of dosage elements of a cleaning composition, a collection area formed in a lid area of said device adapted to collect water/wash liquor in a main wash cycle of a dishwasher, a directing means to direct water or wash liquor from said collection area selectively to an interior part of said device, wherein the device further includes a sieve adapted to prevent or impede particles from blocking water/wash liquor flow into said interior part of the device.

2. The device of claim 1, wherein said sieve is located in a lid area of said device.

3. The device of claim 2, wherein said sieve extends substantially fully across the full available water collection area of said lid.

4. The device according to claim 1, wherein said sieve comprises a non-hydrophobic material.

5. The device according to claim 1, wherein said sieve comprises a non-plastics material.

6. The device according to 5, wherein said sieve comprises a metallic mesh.

7. The device according to 6, wherein said sieve comprises a stainless steel mesh.

8. The device according to claim 6, wherein said mesh has a mesh size of between 3.5 mm and 0.2 mm.

9. The device according to claim 6, wherein said mesh has a mesh size of between 1 mm and 0.4 mm.

10. The device according to claim 9, wherein said sieve comprises market grade, plain square weave, 304 stainless steel.

11. The device according to claim 6, wherein said mesh has an aperture size in the range of 0.4 mm to 0.42 mm.

12. The device according to claim 6, wherein said mesh comprises wire having a diameter in the range of 0.2 to 0.24.

13. A method of using a machine dishwasher for washing wares, comprising the steps of: placing the device according to claim 1 within a wire basket/rack of a dishwasher, and, operating the machine dishwasher through at least one machine dishwasher cycle.

14. (canceled)