This invention relates to a dispensing system to be used for solid detergent products for institutional washing machines.
The invention also relates to a detergent supply pack and a dispensing device, which are adapted for use in a dispensing system according to the invention.Furthermore, the invention relates to a method of dispensing a solid detergent product into the wash liquor to be fed to a washing machine.
Hitherto, various products and packs have been developed to provide institutional washing machines, especially dishwashing machines, with a supply of detergent material from which measured amounts of detergent product are dispensed to the wash liquor in the washing machine. These products include detergent products in powder-form, in liquid-form and in paste-form, which are generally packed in supply packs or containers. More recently, solid detergent blocks for institutional washing machines have been developed, which have the advantage of being discretely shaped.
Furthermore, solid detergent blocks can contain more concentrated product than the other above-mentioned product types. These block-form detergent products are generally dissolved by simply spraying with water in a dispensing device, and then are delivered to the wash liquor. Since detergent products which are suitable for use in institutional washing machines, often have a high alkali content, contact with the skin should be avoided. Block-form detergent products appear to be very suitable for avoiding skin contact.
US-A-4,569,781 (Ecolab) describes a detergent container for a cast detergent solid suitable for use in dishwashing machines. The container contains a detergent product produced from a melt and allowed to solidify. The detergent product is subsequently dissolved from the container on contact with a stream of aqueous liquid from a spray means when placed in a dispensing device. The advantage of a block form detergent product and dispensing device of this type is that, with proper handling, contact with the skin is virtually eliminated. Owing to the shape thereof, however, the container described in this patent has shown to leave residues of detergent after emptying by spraying. This situation is unacceptable for economic, safety and environmental reasons. Detergent residues in the container are a potential danger source to the user when a supposedly empty container is being replaced by a completely full container.
Moreover, from an environmental point of view such a rigid container is less attractive because of its impact to the environment and non-collapsibility.
US-A-4,426,362 (Ecolab) describes a dishwasher distributor for a solid block form moulded detergent product. The block form detergent product of this reference is positioned with its casting mould in the receiving means of the distributor so that the casting mould surrounds the detergent block during the flushing out process and touches it on all sides except for one free face. Once again, contactless handling of the detergent product is provided, but once again, complete emptying is not guaranteed.
US-A-4,774,014 (Henkel) discloses a detergent supply pack for a cast detergent block which pack is suitable for ready dissolution of the block in the dispensing device associated with an institutional dishwashing machine, such that water consumption is not appreciably higher than in the case of powder-form detergents, even towards the end of the block.
However, the detergent supply pack has to be opened before positioning the pack in the dispensing device and therefore skin contact with the alkaline detergent is possible.
EP-A-374,773 (Nors Hydro) discloses a flexible supply pack with a closing/release device comprising two parts and having means for partial or complete discharge therefrom.
EP-A-225,859 (Ecolab) and EP-A-231,603 (Ecolab) disclose chemical dispensing systems comprising a detergent supply pack for supplying solid state detergent material to a dispensing device associated with a washing machine, which supply pack comprises packaging material for said solid state detergent material and a closing/release device for promoting release of the detergent solid from the supply pack into the dispensing device, whereby the closing/release device consists of two parts.
It is an object of the present invention to provide a detergent dispensing system comprising a detergent supply pack for a detergent powder or, preferably, a block form detergent product and a dispensing device associated with an institutional washing machine, preferably a dishwashing machine, whereby an economic and effective use of the detergent in the dispensing device is ensured.
It is an other object of the invention to provide a detergent dispensing system whereby the detergent supply pack is adapted to the dispensing device such that the detergent can be introduced into the device without the need to open the pack before positioning the pack in the dispensing device and loading the device. This eliminates the risk of any skin contact and thus contributes to safety.
It is a further object of the invention that no residue is left inside the supply pack after emptying and that a minimal amount of packaging material is to be disposed of after introducing the detergent product into the dispensing device.
It was found that these and other objects can be accomplished by a detergent dispensing system according to the present invention.
The present invention provides a dispensing system comprising a detergent supply pack for supplying solid state detergent material to a dispensing device associated with a washing machine which supply pack comprises packaging material for said solid state detergent material and a closing/release device for promoting release of the detergent solid from the supply pack into the dispensing device, whereby the closing/release device consists of two parts, characterized in that the packaging material in fixed in between these two parts, in that these two parts are oblong parts, the dimensions of which being such that one of these parts can be placed inside the other part while leaving room to fix the packaging material of the supply pack, whereby the cross-section of the inner oblong part is shaped as a triangle and the outer oblong part is shaped as a hollow tube open to one side, and in that the closing/release device has means to fix the inner part with the outer part, whereby one of these parts is provided with a handle enabling removal of the whole closing/release device from the supply pack for opening the supply pack and introducing the detergent solid into the dispensing device.
The invention also provides a method of dispensing a solid detergent product into the wash liquor to be fed to a washing machine, whereby a dispensing system according to the invention is applied.
The invention provides a dispensing system comprising a supply pack for a solid state detergent product, which may contain detergent powder, detergent briquettes and/or detergent tablets. However, the supply pack preferably contains a compacted detergent block, which is readily dissolvable on contact with flushing water.
The supply pack includes flexible packaging material which functions as a protective means against moisture uptake and also as a handling aid for the introduction of the naked detergent block into the detergent dispensing device of a washing machine, preferably a dishwashing machine, without contact with the skin. The packaging material is generally also collapsible in order to minimize the volume of packaging material to be disposed of after emptying the supply pack. As packaging material, any material which can perform the above mentioned functions, may be used, such as cardboard, coated paper, and laminated material, but plastic material such as polyethylene and polypropylene is preferred. The most preferred type of packaging material is polyethylene.
If a solid detergent block is applied, the supply pack of the invention thus comprises flexible packaging material which conforms to the shape of the detergent solid, a solid detergent block which is usually produced by compaction of dry mixed powder, and release means for releasing the solid detergent product from the supply pack into the distributing device.
Generally, solid detergent blocks constitute a non-dusty and therefore attractive product form in view of the often aggressive chemicals used. Furthermore, they are economical in use because they can be manufactured and transported as very concentrated products. In EP-A-375,022 (Unilever) information can be found with respect to the type of solid detergent block which is preferably used with the supply pack according to the present invention.
In order to eliminate skin contact, the supply pack of the invention comprises a closing/release device essentially consisting of two parts in between which the flexible packaging material of the pack is fixed. In other words, these parts act as a sort of closing clamp for the detergent supply pack.
These parts have an oblong shape, whereby their dimensions are such that one of these parts can be placed inside the other part while leaving just enough room to fully close the supply pack.
The cross-section of the inner part is shaped as a triangle and that of the outer part as a hollow tube open to one side.
The inner part is connected to the outer part in order to ensure simultaneous removal of both parts when opening the pack. For reasons of easy handling, inner and outer part are preferably connected by way of a plastic hinge.
Furthermore, the dispensing system according to the invention comprises a dispensing device of which the dimensions are such that solid detergent material, preferably a solid detergent block, can be effectively and safely introduced into it from out of a detergent supply pack according to the present invention. If a solid detergent block is to be applied, the supply pack containing the detergent block is placed on a support to facilitate the introduction of the detergent block into the dispensing device when opening the supply pack by removal of the closing device. Thereafter, the naked detergent block is allowed to fall down onto a grid-type support provided with a flexible sealing in the bottom part of the detergent dispenser, such that only the bottom side of the block is contacted with water originating from a spray nozzle situated underneath this support. By contacting only the bottom part of the detergent block, excessive degradation of moisture-sensitive components present in the block is avoided.
This configuration is advantageous as the distance between the bottom side of detergent block and the spray nozzle will not vary during the washing operation resulting in a constant dissolution rate of detergent material and consequently a constant concentration of detergent product in the wash liquor fed into the washing machine.
In order to ensure that the dispensing device cannot be opened just after adding fresh solid detergent material, it is desirable that the device can only be opened after the detergent solid inside the device has decreased to below a certain level. For ensuring a continuous operation of the dispensing device, an indicator or alarm is preferably provided signalling that the device can be opened and a new detergent solid introduced.
The invention is further illustrated by Figures 1-7, of which:
Referring more in detail to these drawings, in Figure 1 (1) indicates the tube-shaped outer part of the closing/release device, in which the triangle-shaped inner part (2) is situated. Also means (3a) is shown by which the inner part is connected to the outer part. As a result, using handle (3) the entire closing device can be removed from the supply pack (4), which is depicted in Fig. 2.
As shown in Figure 3, this supply pack can be introduced into the dispensing device (6) by way of handle (5).
The dimensions of this dispensing device which is schematically shown in Figure 4-7, are such that the contents of the detergent supply pack can be safely and effectively introduced into it. Before introducing the contents of supply pack (4), a top lid (12) of the device (6) is turned from a horizontal into a fixed vertical position (see Figure 5).
Thereafter the supply pack is placed on top of a spring-loaded support lid (7) and the handle (5) of the supply pack is positioned onto hook (11) which is connected to the top lid (12) (see Figure 6).
By pulling handle (3) in order to remove the entire closing device and pushing a spring-loaded lever (10) backward, the detergent material is made to fall into the dispensing device and to push the support lid (7) into a vertical position. Thereafter, the lever (10) is pushed back into its position of preference by action of spring (13).
After the empty supply pack is removed, the top lid (12) can be closed and the inner part of the hook (11) automatically fixed by the action of the spring loaded lever (10). As a result, the dispensing device is completely closed and cannot be opened by unauthorised people (see Figure 7).
During operation, the detergent material (14) is positioned on a grid-type support (9) provided with a flexible sealing and being sprayed on by way of spray-nozzle (8). The fexible sealing connected to th grid-type support is located such that only the bottom part of the detergent material is contacted with water.
When the detergent material inside the dispensing device (6) has been dissolved so far that the spring loaded support lid (7) has turned back into a horizontal position (see Figure 4), lever (10) turns such that the fixation of the top lid hook (11) is released. Support lid (7) thus acts as an indicator telling the operator that the contents of a new supply pack can be introduced into the dispensing device.
For this purpose, support lid (7) may be connected to an alarm system which is activated when the fixation of the top lid hook (11) is released.