EP1347039A1 - Process for Cleaning Dishes - Google Patents

Abstract

Washing of kitchen- or table-ware comprising spraying with an alkaline cleaning solution of pH at least 10 prior to the main washing step using an enzymatic composition, is new.

Description

The invention relates to a method for cleaning dishes.

In the commercial sector (catering, canteen kitchens, etc.) Dishes are usually machine washed. Commercial dishwashers have short washing cycles because the dishes are quickly available for further use should. The removal of dried, encrusted or burnt-in food residues and other soiling is difficult because neither mechanical action with Brushing or the like in automatic dishwashing is possible, a long exposure time of chemical cleaning agents (such as household dishwashers) is possible. It is therefore known from obvious prior use particularly dirty dishes such as Pots, pans or baking sheets in a separate container soak in a detergent solution, only then carried out the usual mechanical cleaning. This is expensive.

a) Besprühen des Geschirrs mit einer alkalischen Reinigerlösung, die einen pH-Wert von wenigstens 10 aufweist,

b) Hauptreinigen mit einer enzymatischen Reinigerlösung.

Zunächst seien einige im Rahmen der Erfindung verwendete Begriffe erläutert.The invention has for its object to provide a method for cleaning dishes that allows a safe removal of stubborn dirt. The method according to the invention has the following steps:

a) spraying the dishes with an alkaline cleaning solution which has a pH of at least 10,

b) Main cleaning with an enzymatic cleaning solution.

First, some terms used in the context of the invention are explained.

The term tableware includes all used in the kitchen area Objects accessible for machine cleaning are, including pots, trays, pans, frying and Baking trays, etc.

According to the invention, these dishes are made with an alkaline Sprayed cleaner solution. The cleaning solution is ready to use Solution, usually from a liquid Cleaner concentrate or a solid (especially powder) formulated cleaner is made with water. It can be normal tap water (city water), act softened or demineralized water.

The spraying according to the invention is preferably a fine mist-like spray that covers the surface of the dishes with the detergent solution, without mechanical (in the form of hard water jets) on this surface act. The spraying should therefore have a chemical effect the cleaning solution and thus soaking the contaminants enable. According to the invention, however, it is also possible this spraying with large amounts of detergent solution and to carry out so-called hard spray jets, especially when if the alkaline detergent solution in a tank of a dishwasher is constantly circulated.

The main cleaning is carried out according to the invention with an enzymatic Cleaning solution. This contains enzymes as cleaning-active Active substances, preferably proteolytic enzymes such as, for example Amylases or proteases.

The invention is based on the surprising finding that the combination of a highly alkaline pre-cleaning with a enzymatic main cleaning for a good and quick removal even stubborn contaminants such as burnt food remains.

The pH of the alkaline cleaning solution is preferred at least 10.5, more preferably at least 11.

The preferred fine spraying with appropriately finely distributed According to the invention, droplets can be obtained with relatively small amounts Quantities of alkaline cleaning solution are carried out per unit of time. In a typical commercial dishwasher the amounts of cleaning solution sprayed in this way between 0.3 and 20 l / min, preferably 0.5 to 10 l / min, more preferably 1 to 5 l / min detergent solution. If an alkaline cleaning solution through the pumping system of the Dishwasher turned over and with hard spray jets the dishes are sprayed, the sprayed detergent solution amounts are usually at a few hundred l / min, typical are, for example, 300 to 400 l / min.

The alkaline detergent solution works preferably between 5 and 600 s, more preferably 10 and 300 s, more preferably 30 and 300 s, particularly preferably 60 to 180 s on the Dishes. This action can be continued Spraying the dishes (either with a fog-like spray or hard spray jets) happen. Is preferred it, however, after completely wetting the surface of the Tableware to provide an exposure time in which no further targeted and deliberate spraying of dishes with alkaline Detergent solution takes place.

The alkaline concentration in the alkaline cleaning solution is (calculated as potassium hydroxide) preferably 0.1 to 10 % By weight, preferably 0.1 to 5% by weight, more preferably 0.1 to 3% by weight, more preferably 0.2 to 2% by weight.

The method according to the invention can be used in so-called one-tank systems can also be carried out in multi-tank dishwashers. In In-tank dishwashers, the dishes remain stationary in the Dishwasher and the various washing and cleaning steps are carried out sequentially. In a one-tank dishwasher is therefore when applied without further spraying the corresponding nozzle system is completely switched off. It is particularly advantageous for a single-tank machine for spraying the alkaline cleaning solution anyway to use existing nozzle system that for applying the Rinse aid and / or rinse water is used. To this According to the invention, a customary one-tank dishwasher can can be used without this being converted or expanded would have to be with a separate nozzle system. With a multi-tank machine passes through the dishes on a transport device (usually a conveyor belt) various so-called Tanks in which all cleaning and rinsing steps (each one per tank) run simultaneously. To achieve one Exposure time without deliberate spraying can in this case a corresponding space between two Tanks are provided that the dishes pass through without doing so to be targeted by spray jets.

In practice, spraying for 12 s can follow, for example of an exposure time (without further spraying) of 120 s may be provided.

A main cleaning follows the spraying according to the invention with an enzymatic cleaning solution. This Main cleaning can be done immediately after spraying (and the act) that are still done on the dish surface alkaline cleaning solution is then from washed off with the enzymatic cleaner. Alternatively, one Intermediate rinsing may be provided to remove the alkalinity from the dish surface largely eliminate. You work without Intermediate rinse, becomes alkaline adhering to the surface Detergent solution dragged into the main cleaning step, see above that possibly enzymatic cleaner in correspondingly larger amounts must be added to the desired composition the main cleaner solution. This is particularly so then the case when the enzymatic cleaner used according to a preferred embodiment of the invention a weakly acidic to weakly alkaline pH of in particular 4 to 9, preferably 5 to 9, more preferably 6 to 8. In this pH range, the used Enzymes work best.

The main enzymatic cleaning preferably takes 1 to 30 minutes, more preferably 2 to 20 minutes, more preferably 5 to 15 minutes. The main cleaning temperature is preferred between 30 and 70 ° C, more preferably 40 to 60 ° C. In in this temperature range they are generally heat-unstable Enzymes particularly effective.

The enzymatic main cleaning solution can preferably contain 0.08 to 2% by weight of surfactants, examples being NC ₈ -C ₁₂ alkylpyrrolidones. It can also contain 0.005 to 0.125 Anson units of at least one protease and / or 0.1 to 6 kilo-Novo units of at least one amylase per liter of cleaning solution. The desired pH value is set by means of suitable buffer systems such as, for example, the carbonate / bicarbonate buffer system or citric acid / citrate or the like. Possibly. it can contain conventional solubilizers such as, for example, short-chain sulfonates, sulfates or the like, further surfactants such as, for example, adducts of ethylene oxide and propylene oxide with fatty alcohols, preservatives, hardness dispersants and the like. This list of possible components is not exhaustive.

In the process according to the invention, spraying with is more alkaline Detergent solution and subsequent main cleaning no final list of the process steps. It usual pre-rinsing steps (for example a so-called pre-cleaning) be provided between alkaline spraying and enzymatic main cleaning can be a previously mentioned intermediate rinse be provided. Usually follows the main cleaning a rinse or rinse that with a usual rinse aid solution can happen.

Embodiments of the invention are explained below. All details are parts by weight.

example 1

An alkaline cleaner concentrate is produced according to the following recipe: Sodium hydroxide, 45% 65,00 Potassium hydroxide, 45% 19,00 Sodium hydroxide, solid 10.00 DTMP , Na salt 3.00 PBTC 3.00

Example 2

An enzymatic cleaning solution is prepared as follows:

25 g of a commercially available block adduct of 5 mol of ethylene oxide and 4 mol of propylene oxide with a technical C ₁₂ / C ₁₄ fatty alcohol, 1 g of Nn-octylpyrrolidone, 5 g of a commercially available aqueous solution of a mixture of amylases and proteases with an activity of 1.5 Anson Units or 50 kilo-Novo units per liter, 0.4 g sodium bicarbonate and 0.1 g sodium carbonate are made up with 100 ml Hamburg city water. A conventional polyacrylate dispersant is added up to a concentration of 100 ppm.

Example 3

Soiled in a one-tank container dishwasher Roasting trays placed. In a first step, these sheets 12 s with a 1% aqueous solution of the alkaline Sprayed cleaner according to Example 1. This spraying is done by feeding the solution into the supply lines to the rinse nozzles, which after cleaning is finished Spray on rinse aid. The surface of the roasting pans will completely wetted.

The alkaline solution is left to act for 120 s without that a further spraying takes place. Subsequently cleaning with a factor of 10 with water dilute enzymatic cleaning solution of Example 2. This Detergent solution is in the dishwasher for 10 min continuous spraying and rinsing of the roasting pan. The temperature of the cleaning solution is 60 ° C.

After completing the main cleaning, rinse with a usual rinse aid (duration of rinse aid step 12 s).

Burnt and crusted food scraps can come on completely removed from the roasting pan.

Claims (9)

Procedure for cleaning dishes with the steps: a) spraying the dishes with an alkaline cleaning solution which has a pH of at least 10, b) Main cleaning with an enzymatic cleaning solution. A method according to claim 1, characterized in that a fine, mist-like spraying takes place in step a). Process according to claim 2, characterized in that in step a) 0.3-20 l / min, preferably 0.5-10 l / min, further preferably 1-5 l / min, of cleaning solution are sprayed. Method according to one of claims 1 to 3, characterized in that the alkaline cleaning solution is allowed to act for 5-600 s, preferably 10-300 s, further preferably 30-300 s, further preferably 60-180 s. Method according to one of claims 1 to 4, characterized in that the alkali concentration (calculated as KOH) in the cleaning solution 0.1-10% by weight, preferably 0.1-5% by weight, further preferably 0.1- 3% by weight, more preferably 0.2-2% by weight. Method according to one of claims 1 to 5, characterized in that the enzymatic cleaning solution used in step b) has a pH of 4-9, preferably 5-9, more preferably 6-8. Method according to one of claims 1 to 6, characterized in that the main cleaning in step b) lasts 1 - 30 min, preferably 2 - 20 min, further preferably 5 - 15 min. Method according to one of claims 1 to 7, characterized in that the enzymatic cleaner contains proteolytic enzymes. Method according to one of claims 1 to 8, characterized in that the main cleaning takes place at a temperature of 30-70 ° C, more preferably 40-60 ° C.