The present invention relates generally to chemical compositions, and more particularly, to specialty cleaning compositions which are useful in difficult applications, particularly those of cleaning cooking pots, pans and food service utensils.
It is well known that cooking utensils, such as pots, pans and flatware are soiled in use by a great variety of naturally occurring products which are difficult to remove. For example, during the time when a pot or kettle is used in kitchen service, it may, through ordinary use, oversight or neglect, accumulate numerous layers of baked-on, carbonized grease, protein material, and other decomposition products of food. In restaurant use, cooking pots and pans as are exposed to high temperatures for long periods of time, and are used to cook a large variety of products. These include meats, fats of various kinds, and fruits and vegetables. Such products, in turn contain not only proteinaceous material, but certain enzymes as well. Common foods also includes sugars, starches, and salts of various kinds.
When used continually, utensils are also exposed to spices and seasonings, various salts, and acids and bases. These include, for example, citric and other acids from fruits, various esters and alcohols, and certain relatively complex materials including dyes or dyelike compounds. Over a period of time, the residues of these compositions become hardened and baked on to the pans. The removal of such residues is very difficult because the compositions are no longer simply oils and greases which can be removed by conventional soaps.
In commercial food service, such as restaurant hotel, and catering operations, it is simply not practical to analyze the nature of each separate utensil stain or other residue, and consider the underlying substrate before attempting to clean it. Thus, various individual stains can be removed from most known kinds of cooking utensils by simple abrasive scrubbing, certain other materials may be removed by relatively long soaking, and still others may be treated by stronger, relatively rapidly acting chemicals. However, many compositions which are very effective against some stains are not considered safe for use with aluminum, a common constituent of food service utensils.
Other compositions are not desired for use with resin (commonly polymeric tetrafluoroethylene "TFE") coated products, while still others are considered damaging to stainless steel or copper. With the limited training facilities available for kitchen help, and with the need for speed and efficiency of cleaning, it is not uncommon for kitchen help not to differentiate among the materials from which various cooking utensils are made, and consequently either to fail to clean them effectively, or use cleaners which are adapted to clean one type of substrate but which are ineffective, or sometimes actually dangerous to others.
In particular, while there has always been and continues to be a strong need and demand for effective restaurant or other commercial cookware cleaners, there has heretofore been a lack of a suitable cleaning composition which is highly effective with both steel and aluminum, without being damaging to either.
Extended soaking is a very effective way of softening most cooking residues and dissolving them away, is not labor-intensive, and is simple. However, until the present, cleaners which are simple and safe for cooking residue have not been suitable for long term soaking of both aluminum and steel.
Many of those cleaners which were strong enough to soften deposits on steel actually attacked aluminum and dissolved it to the point where such cleaners could not be used. Other aluminum cleaners were generally not satisfactory for safe long-term soaking of aluminum, and were required to be watched and timed carefully to avoid damage. Alkali cleaners, because of their ability to saponify greases and oils, are highly desirable, but ordinarily attack aluminum in the absence of effective inhibitors. Inhibitors such as phenols, potassium salts of permanganates and chromates, are effective chemically but create problems of toxicity and color residue. Other compositions have further drawbacks, such as generating foam, or allowing redeposition of cleaned materials. Some inhibitors have been successful, such as those identified in my U.S. Pat. No. 4,613,449, but these inhibitors sometimes tend to form a gel or become unduly thick when not continually agitated. Moreover, there is still room for improvement generally in these compositions.
Consequently, there is and has been a demand for corrosion inhibitor systems which are non-toxic, which are safe in an environment surrounding food preparation and serving, and which will clean steel and/or iron, but yet not damage aluminum utensils, even after considerable time, and which possess improved corrosion inhibitors and displays desirable non-gelling characteristics.
According to the present invention, a cleaning system is provided which uses a relatively strong alkali, and a broad-spectrum inhibitor system comprised of a simple sugar, a calcium donor, sodium citrate, and an organic, nonionic antifoaming agent. The prior art having failed to provide an effective, strong cleaner which will remove cooking residues and yet not affect aluminum adversely, even upon relatively long soaking, it is an object of the present invention to provide an improved cleaner which is safe in food service environments and which include strong, long-term corrosion inhibitors to provide safety in use with aluminum.
Another object of the invention is to provide an aluminum cleaner and improved corrosion inhibitor system which is adapted for use in a commercial kitchen environment.
Yet another object of the invention is to provide a commercial cleaning system for food service articles which is economical to produce, and easy and long-lasting in use.
A further object of the invention is to provide a composition for cleaning cooking utensils which includes water, a strong base, together with an inhibiting system consisting of a simple sugar, sodium citrate, a calcium salt, and an anti-foaming additive.
A still further object of the invention is to provide an improved method of cleaning pots, pans and the like by immersing them totally over a long period in a solution containing materials adapted to attack stains and cooking residues on cookware without adversely affecting the aluminum from which the cookware is made.
Another object of the invention is to provide a highly effective aluminum cleaner and brightener which includes an inhibitor system which provides improved performance in respect to prior art calcium-sucrose inhibitors but which requires the use of far less sucrose to obtain equal or better results in use.
The foregoing and other objects and advantages of the inventions are achieved and practiced by providing a cleaner which includes, by weight, about forty to one hundred parts of water, 1 to 5 parts by weight of a strong caustic, 0.1 to 0.3 parts of calcium salt, 0.1 to 0.3 parts sucrose or like sugar, and 1.0% to 2.0% sodium citrate and up to 5.0 parts of a nonionic antifoaming additive. A nonionic or other surfactant, such as, an alkylphenyl polyethyleneglycol ether may be added, if desired.