Method and apparatus for cleaning objects in an automatic cleaning appliance using an oxidizing agent

Abstract

A method and apparatus for cleaning objects in an automatic cleaning appliance is provided that includes the steps of introducing a load of objects into a wash zone of the automatic cleaning appliance, applying a wash liquor and at least one of electromagnetic, chemical and mechanical energy to the load of objects in the wash zone to remove soil from the load of objects, and subsequently applying an oxidizing agent to the load of objects through the medium of a fluid applied to the load of objects. The oxidizing agent may be generated in association with the automatic cleaning appliance.

Description

BACKGROUND OF THE INVENTION [0001] Cleaning a soiled load of objects in automatic cleaning appliances generally involves the use of chemical energy (such as detergent), mechanical energy (such as through agitation of the object load in a wash liquor or the manner of dispensing the wash liquor against the object load, such as spraying) and / or thermal energy (such as through an elevated temperature of the wash liquor). Different combinations of these energy inputs provide various levels of soil removal from the load. Depending on the type of objects in the load, there may be attendant damage, such as when the load comprises fabric, resulting in the generation of lint or the fading of various colors of the fabric, etc. Other types of objects could be subject to chemical etching or other types of damage. [0002] Numerous types of chemical wash additives are known, such as detergents which include surfactants and emulsifiers, as well as enzymes, all used to dissolve, loosen and / or remove ...

AI Technical Summary

Benefits of technology

[0006] A method and apparatus for cleaning a soiled load of objects in an automatic cleaning appliance is provided which overcomes the problems noted above and permits the use of an oxidizing agent in an automatic cleaning appliance so that it does not detract from the effectiveness of the chemistry of the wash liquor and which does not pose a thermal load on the wash liquor while the wash liquor is being applied to the objects in an elevated temperature enhanced wash process.

[0010] The method of the present invention may be practiced in an automatic cleaning appliance wherein the wash zone is arranged to rotate about a vertical axis or where the wash liquor is dispensed from a rotating spray arm. In such a machine, the oxidizing agent may be introduced to the wash zone in a lower region of the wash zone in order to assure a proper mixing of the oxidizing agent with the wash liquor before it is introduced to the object load. An additional embodiment includes adding the oxidizing agent to the top of the wash bath after a majority of the working fluid has entered the bath. Optionally, the oxidizing agent may be introduced via a recirculation pump that takes fluid from the sump and re-introduces the flow into the top of the tub. Finally, the oxidizing agent may be added simultaneously to the lower region of the wash zone as well as the top half of the wash zone through a flow splitter or diverter valve. This option provides the aforementioned mixing advantage as well as providing direct contact of the oxidizing agent to the soiled objects.

Problems solved by technology

Depending on the type of objects in the load, there may be attendant damage, such as when the load comprises fabric, resulting in the generation of lint or the fading of various colors of the fabric, etc.

Other types of objects could be subject to chemical etching or other types of damage.

With a fashion trend changing from white fabric to vibrant colors, the use of chlorine-based bleaches has become problematic.

One of the potential drawbacks associated with oxygen bleaches is that they have an adverse effect on some of the components found within many detergent formulations.

For example, the hydrogen peroxide can deactivate enzymes, thus decreasing the washing performance of automatic cleaning appliances.

The application of additives to the wash liquor places a thermal burden on the wash liquor, in those situations where the wash liquor is heated above ambient temperature to provide thermal energy to the soil removal process.

Typically the additives are maintained at ambient temperature, so additional energy is required to elevate the additives to the temperature of the wash liquor, or else the temperature of the wash liquor is detrimentally lowered upon the addition of the additives.

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