EP0806472B2 - Cleaning kit for crockery and process therefor - Google Patents

Abstract

Dish-washing process comprises: (a) prewashing with a solution of an organic acid and/or a chelating agent for alkaline earth ions; (b) main washing with an enzymatic detergent solution; and (c) rinsing. Also claimed is a kit for carrying out the process

Description

The invention relates to a method for cleaning of screen in a multi-tank dishwasher as well as a kit consisting of pre-cleaner and main cleaner for use in this process.

The mechanical cleaning of dishes is widespread in the commercial sector. The use of enzyme-containing cleaners for this purpose is known, for example, from EP-B-0 578 666. Difficulties in machine cleaning of dishes often cause the removal of tannins, particularly those contained in coffee and tea, which, for example, are deposited on the skin in the form of iron complexes and form unsightly deposits there. To ent. Removal of tannin deposits usually requires aggressive (e.g. highly alkaline or active chlorine-containing) cleaning agents. To remove protein and starch deposits, the machine was proposed. upstream of a soaking bath after cleaning, contains : contains both enzymes and complexing agents (DE-A-17 92 359). However, since the soaking bath is not part of the mechanical cleaning, this procedure has proven to be. accordingly as cumbersome.

The invention is based on the object Process for cleaning dishes that without using overly aggressive cleaning agents extensive removal of tannins or tannin coverings of dishes.

a) Vorreinigen mit einer Lösung einer organischen Säure und/oder eines Komplexbildners für Erdalkaliionen wobei die Vorreinigerlösung auf einen pH-Wert von 2-5 gepuffert ist;

b) Hauptreinigen mit einer enzymatischen Reinigerlösung;

c) Nachspülen.

The inventive method defined in claim 1 has the following steps:

a) pre-cleaning with a solution of an organic acid and / or a complexing agent for alkaline earth ions, the pre-cleaning solution being buffered to a pH of 2-5;

b) main cleaning with an enzymatic cleaning solution;

c) rinsing.

Below are some in the frame terms used in the invention are explained.

The term "cleaning solution" (e.g. preliminary or Main cleaning solution) actually refers to the solution brought into contact with the dishes, which in the Usually obtained by diluting a cleaner with water becomes. The cleaning solution can be ready to use Preparation available in a storage container be and without further dilution with the dishes will usually be brought into contact however, the cleaning solution from a cleaner (usually a concentrate) by dilution with water.

The term "pre-cleaning" refers to one the process preceding the main cleaning, which is not must necessarily be the first step. Within the scope of the invention, further pre-cleaning steps, that are not defined in claim 1, be upstream. For example, a first pre-cleaning step (Pre-rinse) to remove coarse dirt be provided. Such a pre-rinse or clearing advantageously only takes place with Water without the addition of detergents, especially enzymatic detergents instead. It has showed that after clearing the dishes remaining detergent residues the effect affect the pre-cleaner solution sprayed on in step a) can. A complexing agent for alkaline earth ions is any substance that contains alkaline earth metals (in particular Calcium and / or magnesium) in aqueous solution can complex. An enzymatic cleaning solution is a wash liquor that uses enzymes as cleaning agents Contains substances. Usually the main cleaning solution other active ingredients such as surfactants, defoamers and contain other additives.

The term "rinsing" includes all following the main cleaning according to the invention Cleaning and / or rinsing steps. As part of the invention, it is conceivable that the invention Main cleaning is another main cleaning step with another cleaner. On this second main cleaning then closes the usual one Rinse and / or rinse. Usually will however, the main cleaning according to the invention directly a rinse aid (usually with a normal rinse aid), if necessary, a (further) rinse with water consequences. All of these variants are used by the 1 term used "rinse" includes.

The invention is based on the surprising Realization that the combination of a pre-cleaning step with the means mentioned in claim 1 and a subsequent main cleaning with an enzymatic Detergent solution to a particularly good one Tannin removal leads. This was for the specialist not to be expected since neither an organic acid nor a complexing agent and an enzymatic cleaner each alone for a good cleaning effect Has tannins. The pre-cleaning step alone accordingly leads to none or at most a slight removal of tannins or Tannin deposits, but this seems figuratively speaking to "loosen" so that a far distance in the subsequent main cleaning step with a enzymatic cleaner is possible.

The pre-cleaner can be mono- and / or dicarboxylic acids contain 1 - 3 carbon atoms. Preferred under these acids are formic and / or acetic acid, formic acid is particularly preferred. As a pre-cleaner For example, a 0.1-80%, preferably 30-50%, more preferably about 40% solution of formic acid in water (preferably fully desalinated or fully softened water with less than 0.1 ° dH) use Find. Lower concentrated formic acid solutions (e.g. 5 - 10%) can also be advantageous be used. A formic acid solution with a the concentration is below 10% unproblematic and only as "lovely", not however, like more concentrated solutions, as "caustic" Classified. With all percentages Unless otherwise stated, it is Weight. When using this cleaner with water (preferably fully desalinated or fully softened water) diluted to a cleaning solution. The cleaning solution preferably contains 0.01 - 1%, more preferably 0.05-0.2% formic acid.

In a further preferred embodiment the invention contains the precleaner (instead of or in addition to the acids mentioned above) complexing organic acids and / or their salts. "Complexing" means that this acid with alkaline earth ions (especially calcium and / or magnesium) can form complexes in aqueous solution. Prefers the pre-cleaner contains at least one acid from the Group of the so-called food acids, these Group includes Citric acid, malic acid, Tartaric acid, lactic acid and / or salts of the aforesaid Acids. The pre-cleaner solution is buffered to a pH of 2 - 5. Be special as a buffer preferably used amines, preferably alkanolamines, more preferably mono-, di- and / or Triethanolamine. It has been shown that amines Reinforce the mesh effect of the pre-cleaner and one more better "loosening" of the organic tanning agents enable.

One has a particularly good network effect Pre-cleaner solution, the citric acid and an alkanolamine (especially monoethanolamine) contains.

The concentration of the total amount from organic Acid and / or complexing agent in the pre-cleaner solution is preferably 0.01-5%, more preferably 0.05 to 1%. The pre-cleaner can, for example, 0.8 - 30% monoethanolamine and 1 - 30% citric acid contain. This pre-cleaner becomes one with water Diluted pre-cleaner solution, preferably in the form that there is a monoethanol concentration in the pre-cleaner solution from 0.01 to 1%, more preferably 0.05 - 0.2% results.

Contacting the pre-cleaner solution with the dishes, for example, by immersing the dishes done in a pre-cleaner solution. Prefers is, however, spraying the pre-cleaner solution onto the Dishes. The term "spray" includes both finely divided spraying as well as showering. When applying the pre-cleaner solution by spraying it is possible to use different components of the Keep the pre-cleaner in separate storage containers, sprayed separately and so only in situ on the Mix dishes. So you can, for example, the organic Acid and / or the complexing agent on the one hand and a buffer on the other hand separately on the dishes be sprayed on. Buffering to the desired one The pH value then only takes place in situ after mixing on the dishes. For example. can be a pre-cleaner component a 0.8 to 40% aqueous monoethanolamine solution be the second pre-cleaner component a 40% aqueous citric acid solution. These components are diluted with water before spraying and sprayed on the dishes pre-cleaner solution created by mixing 0.01-1%, preferably 0.05-0.2% monoethanolamine and contains citric acid. Spraying the pre-cleaner solution or their components can by known Spray frames are made.

It is preferred to leave the pre-cleaner solution sprayed on act on the dishes before main cleaning. The exposure time can range from 2 s to 3 min, preferably about 5 - 30 s. Because to carry out the inventive method a multi-tank dishwasher a certain exposure time results automatically by moving the dishes from Before in the main cleaning course. The action can either with continued spraying or but take place in an area where the dishes is no longer sprayed.

The proportion of the pre-cleaner solution used on the total used for pre and main cleaning Amount of detergent solution (the total amount of Detergent liquor) is preferably 0.1-10%, further preferably 0.1-1%.

The main enzymatic cleaner can in particular Contain proteases, amylases and / or lipases. As proteolytic enzymes are in particular commercially available from bacterial strains Suitable proteases.

• 0,08 - 2 Gew.-% N-C₈- bis C₁₂- Alkylpyrrolidone;
• 0,005 - 0,125 Anson-Einheiten wenigstens einer Protease und/oder 0,1 - 6 Kilo-Novoeinheiten wenigstens einer Amylase pro 1 Reinigerzubereitung;
• Puffer zur Pufferung auf einen pH-Bereich von 5 - 9.

In a particularly preferred embodiment of the invention, the main cleaner contains the following components:

• 0.08-2% by weight NC ₈ to C ₁₂ alkyl pyrrolidones;
• 0.005 - 0.125 Anson units of at least one protease and / or 0.1 - 6 kilo-Novo units of at least one amylase per 1 cleaner preparation;
• Buffer for buffering to a pH range of 5 - 9.

The concentration information given relates to the main cleaner and not to the main cleaner solution. The main cleaner is diluted with water to a main cleaner solution, its concentration in the aqueous solution is preferably 0.1-5%, more preferably 0.2-1%. The NC ₈ - C ₁₂ pyrrolidones contained in the main cleaner, in particular those with straight-chain alkyl groups, are commercially available compounds which are used in the prior art, inter alia, as surface-active agents in cosmetic formulations. The list of constituents in the main cleaner is not exhaustive; there may be conventional additives and auxiliaries, such as, for example, solubilizers, defoamers, fragrances, dyes, thickeners, preservatives and hardness dispersants. The same applies to the precleaner. Here too, the list of components mentioned in the claims and the description is not to be understood as exhaustive.

For example, short-chain Sulfonates or sulfates can be used. typical Examples of any to be added to the cleaner according to the invention Defoamers are biodegradable Adducts of ethylene oxide and propylene oxide with fatty alcohols with cloud points in water of ≤ 50 ° C or of propylene oxide to fatty alcohols. Particularly preferred are ethylene oxide / propylene oxide adducts with fatty alcohols, the commercial block adducts of the number average 2 to 5 moles of ethylene oxide and 2 to 4 moles of propylene oxide to 1 mole of fatty alcohols with 12 to 18, in particular Represent 12 to 14 carbon atoms; you can in the main cleaners in an amount of 1 to 3 % By weight may be included. The aforementioned defoamers are commercially available compounds that are used in the normal Operating temperatures of a dishwasher (approx. 50 to 60 ° C) have a defoaming effect; if necessary, the Main cleaners, if necessary, other common ones Defoamers included. The optimal amount of Defoamer to be added depends on the chain length the N-alkyl pyrrolidone; longer chain connections can have higher proportions of defoamers require.

According to a preferred embodiment of the invention, the main cleaner has a content of NC ₈ -C ₁₂ alkyl pyrrolidones in the range from 0.08 to 1.0% by weight.

According to a further advantageous embodiment According to the invention, the main cleaner has one Protease content ranging from 0.005 to 0.125 Anson units per 1 1 solution.

According to another, particularly advantageous The main cleaner has an embodiment of the invention a content of amylases in the range from 0.15 to 2.0 kilo-Novo units per 1 1 solution.

According to a further advantageous embodiment of the invention, the main cleaner has a pH in the range from 6 to 8 set by means of buffer substances; suitable buffer systems, e.g. B. NaHCO ₃ / Na ₂ CO ₃ and polycarbonates are familiar to the person skilled in the art.

The main cleaner according to the invention is preferred during the main cleaning step Detergent fleet dosed, the pre-cleaned dishes is in a known manner with the main cleaner fleet in Touched, the dishes are immersed, for example or showered with the fleet.

• einen Vorreiniger, der Zitronensäure enthält und mit wenigstens einem Alkanolamin auf einen pH-Wert von 2-5 gepuffert ist, einen enzymatischen Hauptreiniger.

The invention further relates to a kit for carrying out the method according to the invention, which contains the following constituents:

• a precleaner that contains citric acid and is buffered to a pH of 2-5 with at least one alkanolamine, an enzymatic main cleaner.

Advantageous embodiments of the kit contained pre and main cleaners result from the above description of these cleaners in the frame of the method according to the invention in which it is applied become.

The invention is based on Exemplary embodiments explained. As part of this Embodiments are softened as water Hamburg city water with a calcium content below of 0.1 mM / l used.

Manufacture the main cleaner

25 g eines handelsüblichen Blockadduktes von 5 Mol Ethylenoxid und 4 Mol Propylenoxid an einen technischen C₁₂/C₁₄-Fettalkohol mit einem Trübungspunkt in Wasser von 28 - 32°C (Entschäumer),

1 g N-n-Octylpyrrolidon,

5 g einer handelsüblichen wäßrigen Lösung eines Gemisches von Amylasen und Proteasen mit einer Aktivität von 1,5 Anson-Einheiten bzw. 50 Klio-Novoeinheiten pro 1,

0,4 g Natriumbicarbonat und

0,1 g Natriumcarbonat,

ergänzt auf 100 ml Volumen mit Hamburger Stadtwasser; diese Zubereitung wurde mit einem handelsüblichen Polyacrylatdispergator bis zu einer Konzentration von 100 ppm versetzt und wies einen pH-Wert von 7,2 +/- 0,4 auf.

The following ingredients were mixed together:

25 g of a commercial block adduct of 5 moles of ethylene oxide and 4 moles of propylene oxide with a technical C ₁₂ / C ₁₄ fatty alcohol with a cloud point in water of 28-32 ° C. (defoamer),

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 Klio-Novo units per 1,

0.4 g sodium bicarbonate and

0.1 g sodium carbonate,

supplemented to 100 ml volume with Hamburg city water; this preparation was mixed with a commercially available polyacrylate disperser to a concentration of 100 ppm and had a pH of 7.2 +/- 0.4.

The resulting mixture was made up with water diluted a total volume of 1,000 ml.

Pre-cleaner

Vorreiniger 1:

40%ige wäßrige Ameisensäurelösung

Vorreiniger 2:

wäßrige Lösung mit einem Gehalt von 25 % Zitronensäure und 20 % Monoethanolamin.

The following pre-cleaners were used:

Pre-cleaner 1:

40% aqueous formic acid solution

Pre-cleaner 2:

aqueous solution containing 25% citric acid and 20% monoethanolamine.

example 1

For the implementation of the invention The procedure was a Winterhalter 2-tank box transport machine type WKTS-PWZNT 2600 used, the front of the tank for performing the main cleaning a spray device for spraying the Had pre-cleaner solution.

The possibly pre-rinsed and / or mechanically Pre-cleaned dishes are in the pre-cleaning stage sprayed with a pre-cleaner solution. For their manufacture 70 ml per hour of pre-cleaner 1 20 1 Water metered in continuously every hour. In the pre-cleaner solution this results in a concentration of 0.4 % Pre-cleaner 1 (corresponding to 0.16% formic acid).

The sprayed dishes are placed in the main cleaning tank driven, the one in this tank Main cleaner solution contains the main cleaner in one Concentration of 1-10 g / l, preferably 3-5 g / l, further preferably 4 g / l. With a lot of main cleaner fleet of 360 l / h becomes the main cleaner in one Amount of 1.5 l / h continuously to the main cleaning tank added.

After the main cleaning there is a rinse with a normal neutral rinse aid.

Example 2

The pre-cleaner solution was added by metering from 140 ml / h pre-cleaner2 to 20 liters of water per hour manufactured. The concentration of the pre-cleaner 2 in the pre-cleaner solution was 0.8% (corresponding to 0.2 % Citric acid). Main cleaning and rinsing identical to that in Example 1.

When cleaning heavily with tannic acid deposits contaminated coffee / teaware according to these the two embodiments are compared Comparative tests in commercial belt dishwashers, where the pre-cleaning (under permanent spraying) omitted and main cleaning and Rinsing were carried out identically, a clear one Reduction of waste from not clean Dishware to about half.

It should be noted that in these embodiments Amount and pH of the pre-cleaning solutions were chosen so that it was entered the pre-cleaner solution in the main cleaning tank only to a relatively small reduction in the pH of the main detergent fleet is coming. The cleaning effect of the enzymes that are only within one certain pH value is therefore optimally unfolded or only slightly affected.

Claims (16)

1. A method of cleaning dishes in a multitank rinsing machine, characterised by the following steps:

   a) precleaning with a solution of an organic acid and/or a complexing agent for alkaline earth ions; wherein the precleaner solution is buffered to a pH value of 2 - 5;

   b) main cleaning with an enzymatic cleaning solution;

   c) rinsing.
2. A method according to Claim 1, characterised in that the precleaner contains mono and/or dicarboxylic acids having 1-3 carbon atoms.
3. A method according to Claim 2, characterised in that it contains formic acid and/or acetic acid.
4. A method according to any one of Claims 1 to 3, characterised in that the precleaner contains complexing organic acids and/or the salts thereof.
5. A method according to Claim 4, characterised in that the precleaner contains at least one acid from the group comprising citric acid, malic acid, tartaric acid, lactic acid and/or salts of the aforementioned acids.
6. A method according to any one of Claims 1 to 5, characterised in that amines, preferably alkanol amines, more preferably mono, di and/or triethanol amine are used as a buffer.
7. A method according to any one of Claims 1 to 6, characterised in that the concentration of the total quantity of organic acid and/or complexing agent in the precleaner solution amounts to 0.01 - 5 % by weight, preferably 0.05 - 1 % by weight.
8. A method according to any one of Claims 1 to 7, characterised in the organic acid and/or the complexing agent, on the one hand, and a buffer, on the other hand, are sprayed separately on to the dishes.
9. A method according to any of Claims 1 to 8, characterised in that the sprayed-on precleaner solution is left to act before the main cleaning.
10. A method according to any one of Claims 1 to 9, characterised in that the proportion of the precleaner solution used amounts to 0.1 - 10 % by weight, preferably 0.1 - 1 % by weight of the total amount of cleaner solution used for precleaning and main cleaning.
11. A method according to any one of Claims 1 to 10, characterised in that the main cleaner contains proteases, amylases and/or lipases.
12. A method according to Claim 11, characterised in that the main cleaner contains the following constituents:

    0.08 - 2 % by weight N-C₆- to C₁₂- alkyl pyrrolidones;

    0.005 - 0.125 Anson unit of at least one protease and/or 0.1 - 6 kilo-Novo units of at least one amylase per 1 of cleaner preparation;

    buffer for buffering to a pH range of 5 - 9.
13. A kit for carrying out the method according to any one of Claims 1 to 12, characterised by the following constituents:

    a precleaner which contains citric acid and at least one alkanol amine is buffered to a pH value of 2 - 5;

    an enzymatic main cleaner.
14. A kit according to Claim 13, characterised in that mono, di and/or triethanol amine are used as a buffer.
15. A kit according to Claim 13, characterised in that the main cleaner contains proteases, amylases and/or lipases.
16. A kit according to Claim 15, characterised in that the main cleaner contains the following constituents:

    0.08 - 2 % by weight N-C₈- to C₁₂- alkyl pyrrolidones;

    0.005 - 0.125 Anson unit of at least one protease and/or 0.1 - 6 kilo-Novo units of at least one amylase per 1 of cleaner preparation;

    buffer for buffering to a pH range of 5 - 9.