Cleaning and liquid contact with solids – Processes – Work handled in bulk or groups
Reexamination Certificate
1994-04-19
2001-07-10
Soderquist, Arlen (Department: 1743)
Cleaning and liquid contact with solids
Processes
Work handled in bulk or groups
C134S003000, C134S015000, C134S023000, C134S034000
Reexamination Certificate
active
06257253
ABSTRACT:
FIELD OF THE INVENTION
The invention is a method and composition for sanitizing and rinsing ware articles used for the preparation, serving and consumption of food. The invention provides spot-free, film-free ware products upon rinsing with an added sanitizing effect. The invention may be used in either manual or automated washing and rinsing processes to provide a high level of sanitizing efficacy without the harmful drawbacks of certain other sanitizing agents such as halogens. Generally, the sanitizing agent of the invention comprises one or more carboxylic acids and peroxide to result in a composition which preferably comprises, at equilibrium, hydrogen peroxide, carboxylic acid, and peroxycarboxylic acid.
BACKGROUND OF THE INVENTION
In high volume institutional food preparation and service installations, chemical sanitizing compositions are often used in manual and automated ware washing processes to destroy bacteria during rinsing operations to meet minimum sanitation standards. In many installations sanitation standards are met through the use of very high temperature rinse water (180°-195° F.). Where such temperatures are not achievable, a chemical sanitizing agent is often added to one or more aqueous material that contacts kitchenware or tableware to produce a bacteria killing effect at the low temperature conditions of approximately 120-140° F. The use of the terms “high temperature” and “low temperature” herein relate approximately to the above temperature ranges.
Low temperature methods and equipment are illustrated in the following, Fox et al., U.S. Pat. Nos. 2,592,884, 2,592,885, and 2,592,886, 3,044,092 and 3,146,718, as well as Fox, U.S. Pat. No. 3,370,597. In large part, these machines follow a cleaning regimen wherein the soiled kitchenware or tableware can be prescraped either manually or with an automatic machine scraping stage involving a water spray to remove large bulk soil. The ware can then be directed to a zone wherein the ware is contacted with an aqueous alkaline cleaning composition that acts to remove soil by attacking protein, fat or carbohydrate soils chemically. The cleaned ware can then be directed to a sanitizing stage wherein the ware is contacted with sanitizer material. Alternatively, the ware may be directed to a combined rinsing-sanitizing stage where the ware is contacted with a combination of rinse agent and sanitizer. Lastly, the ware can be directed to a stage where the articles are dried either actively by heating or passively by ambient evaporation.
The need for sanitization has lead to the consideration of various agents. One of the most common sanitizers for ware washing is aqueous sodium hypochlorite (NaOCl). However, while sodium hypochlorite is effective, low cost and generally available, sodium hypochlorite has several disadvantages. First, hypochlorite can react with hardness ions in service water including calcium, magnesium, iron, manganese, etc. Such chemical interaction can cause liming and mineral deposits on machine parts. Such deposits can tend to form in and on the water passages of a ware washing machine which can substantially change the flow rates of various aqueous materials through the machine. Any such change can seriously reduce the effectiveness of machine operation. Chlorine, as a constituent of sodium hypochlorite, may also present compatibility problems when used with other chemicals which have desirable sheeting and rinse aid characteristics, such as nonionic surfactants. Further, the interaction between sodium hypochlorite and various minerals in service water can result in the spotting and filming of ware products.
Sodium hypochlorite use tends to substantially increase the total dissolved solids present in aqueous sanitizing compositions. High concentrations of solids can tend to increase the tendency of agents to leave unwanted spotting and streaking upon drying. In fact, while chlorine has a noted sanitizing effect, the increased solids resulting from this constituent can film, spot and otherwise leave a residue on ware products subjected to the rinse. Chlorine may also react and degrade or corrode tableware comprising metals as well as metals found in the environment of use.
Sodium hypochlorite is also a strong oxidizing chemical and can substantially corrode a variety of materials used in machine manufacture and in tableware and kitchenware commonly used in today's institutional environment. Lastly, spills of sodium hypochlorite are unpleasant, can cause damage to bleachable surfaces, and are difficult to clean.
In the meantime, various rinse aid compositions have been developed for use in both low temperature and high temperature wash systems. For example, Fraula et al., U.S. Pat. No. 4,147,559 and U.S. Reissue Pat. No. 30,537 teach an apparatus and a method for rinsing and chemically sanitizing foodware items. The disclosure is primarily directed to machine related components for ensuring adequate cleaning and sanitizing.
Further, a number of rinse aid compositions, based largely on nonionic surfactants without sanitizers are also known. Altenschopfer, U.S. Pat. No. 3,592,774, teaches saccharide-based nonionic rinsing agents. Rue et al., U.S. Pat. No. 3,625,901, teach surfactants used as rinse aids having low foaming properties. Dawson et al., U.S. Pat. No. 3,941,713, teach machine ware washing rinse agents having an anti-resoiling or non-stick additive for treating aluminum or other such metal kitchenware. Rodriguez et al., U.S. Pat. No. 4,005,024, teach a rinse aid composition containing organosilane and monofunctional organic acids that act as rinse agents. Herold et al., U.S. Pat. No. 4,187,121, teach a rinse agent concentrate based on saccharide glycol ether technology.
Further, Morganson et al., U.S. Pat. No. 4,624,713, teach a solidified rinse agent composition containing a nonionic rinsing agent, urea, water and other components. Surveys of nonionic surfactants and rinse additives containing nonionic surfactants are found in Schick, “Nonionic Surfactants”, published by Marcel Dekker, and John L. Wilson,
Soap and Chemical Specialties
, February 1958, pp. 48-52 and 170-171.
However, none of these rinse aids have been able to combine effective sheeting and rinsing action with sanitizing efficacy. Accordingly, a strong need exists in the art to provide a rinsing sanitizing agent that can promote sheeting and removal of spotting, provide substantial sanitizing action, work safely within the environment, and result in operations without any substantial deposit formation on ware or dish machines or corrosion of machine components or kitchenware, tableware, etc.
BRIEF DESCRIPTION OF THE INVENTION
In accordance with a first aspect of the invention there is provided, a method of sanitizing and destaining ware comprising the step of applying a sanitizing, destaining concentrate composition comprising a peroxycarboxylic acid, a C
1-6
carboxylic acid, hydrogen peroxide, and a balance of carrier.
In accordance with a more preferred aspect of the invention, there is provided a method of sanitizing ware without creating a film residue comprising the steps of washing the ware in an automated ware washing machine, and rinsing the ware at a temperature ranging from about 120° F. to 140° F. with a sanitizing destaining concentrate composition comprising peroxy acetic acid, acetic acid, and hydrogen peroxide in an aqueous carrier. Optionally, the rinsing step may also comprise the introduction of a sheeting agent into the automated ware washing machine during the rinsing step or a combined product may be used where the sheeting agent is combined with the sanitizer.
The invention is a method for destaining and sanitizing tableware. The invention generally comprises a peroxyacid material which optionally may be used in combination with effective sheeting agents that provide improved destaining and sanitization, but does not cause significant corrosion of machine parts or ware. We have found that the effective concentration of the materials result in low total solids formulations which substantially res
Baum Burton M.
Groth Dale W.
Lentsch Steven Eugene
Oakes Thomas R.
Ecolab Inc.
Merchant & Gould P.C.
Soderquist Arlen
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