WO2006067439A1

WO2006067439A1 - A method of disinfecting textile articles during laundering and a laundry preparation

Info

Publication number: WO2006067439A1
Application number: PCT/GB2005/004971
Authority: WO
Inventors: David James Dore
Original assignee: Quill International Industries Plc
Priority date: 2004-12-23
Filing date: 2005-12-21
Publication date: 2006-06-29
Also published as: GB0428202D0

Abstract

A method of disinfecting textile articles during laundering is disclosed wherein at least one wash cycle is followed by at least one rinse cycle and at least one laundry preparation is used. The laundry preparation collectively o comprises a terpene, a heat-activated bleach, and a mixture of an anti-microbial agent and a surfactant or an oil. Preferably, the temperature of the water during the wash cycle is maintained between 40°C and 80°C inclusive and preferably at 60°C.

Description

A METHOD OF DISINFECTING TEXTILE ARTICLES DURING LAUNDERING AND A LAUNDRY PREPARATION

5 The present invention relates to a method of disinfecting textile articles during laundering, particularly heavily soiled and biologically contaminated textile articles such as hospital linen, hospital workwear, meat-workers overalls and the like, and to a laundry preparation for use in said method.

10

In commercial laundries, industrial-size washing machines containing up to ioo kg of articles for washing are used which depend on a constant flow of pre-heated water and into which metered quantities of washing powder and adjuncts are pumped by dosing apparatus. Conventionally, in

15 order to wash heavily soiled or biologically contaminated articles such as hospital linen, hospital workwear and the like, it is necessary to use high- temperature water, mechanical action within the washing machine, and high alkalinity and enzyme detergents. In addition, in order to disinfect the wash articles to predetermined standards, United Kingdom National Health

20 Service protocols require that during the washing process the articles are subjected to a temperature of at least 65⁰C for at least ten minutes or a temperatures of at least 71⁰C for at least three minutes. Typically, bleaches, which also act as biocides, are added to the wash to increase the biocidal efficacy of the process. However, this can cause problems because the

25 maximum temperature at which conventional bleaches such as sodium hypochlorite can be used within a washing process is 60⁰C if damage to the washed articles is to be limited. As the washing cycle of such articles usually takes place at around 80⁰C, a separate bleaching cycle must be carried out wherein a cooler water temperature is used. This prolongs the washing

30 process and involves the use of a considerable quantity of water that still requires heating to the appropriate temperature. _ O _

The cost of pre-heating the water to temperatures of 60⁰C and greater for use in the washing process makes up a significant proportion of the cost of such a process. Typically the water is heated by injecting steam into it and significant time and energy is taken up producing the steam for this purpose. Also, as the washing cycle itself is likely to be for times in excess of 20 minutes, steam continues to have to be generated throughout the washing cycle to ensure that the washing liquor is maintained at the correct temperature. Such heavy washing also typically requires at least two and sometimes more rinse cycles to remove the washing preparations from the articles and reduce their alkalinity to acceptable levels. The waste wash and rinse waters are therefore also potentially environmentally damaging.

Also, some fabrics, such as polycottons, which comprise a mixture of synthetic and natural fibres are liable to suffer "thermal shock" if they undergo a water extraction process such as spinning or pressing immediately after a high temperature washing cycle. This means than they become creased in such a way that the creases are set into the fabric until they are washed again. To prevent thermal shock, this type of fabric must be cooled in stages from say an 80⁰C wash down to a 60⁰C wash and then down to a 40⁰C wash before they can rinsed and the spun or pressed. All of this takes considerable time and energy to carry out the required number of wash cycles at different temperatures.

It should also be appreciated that it has been found that thermal disinfection alone, i.e. the subjection of textile articles to an elevated temperature for a predetermined period of time, has been found not to work sufficiently effectively in vitro and especially in the case of spore forming bacteria. Thermal disinfection of textile articles is only effective in a laundry process because the microbes present on the textile articles are subjected to the mechanical action of the washing process, which destroys some of them, and to the dilution of the washing process whereby they are physically washed out of the articles. If water samples are taken from the washing machines used to launder, for example, hospital textiles at various places in the washing process and these samples are plated and incubated at predetermined temperatures for predetermined times, then it is found that a significant number of live bacterial colony forming units can be counted. The details of the tests carried out are given below and it will be appreciated that as live bacterial colonies can be incubated from waste water from the washing process then it is likely that significant numbers of live bacteria and other pathogens remain on the textile articles themselves, surviving the standard thermal disinfection process. The fact that biological agents survive the washing process also means that the waste water from the washing process must be subjected to an additional sterilization process before it can be safely disposed of. Also, periodically it is necessary to sterilize the washing machines themselves as biofilms build up over surfaces of the machines contacted by the waste water.

In the tests, three hospital laundries using conventional industrial- size tunnel washing machines that batch wash up to 35 kg of textile articles at a time per compartment were selected using conventional laundering processes. The water used in and discharged from the machines at five different times during a laundering process using conventional laundry preparations and bleaches was sampled. The samples were taken from the following five parts of the washing machine.

1. The main fresh water feed inlet into the machine.

2. The pre-wash tank where final used rinse water is mixed with new wash water for use during the next washing cycle.

3. The main wash drain where used waste water from the main washing cycles is discharged.

4. The rinse drain where used rinse water from the rinsing cycles is discharged. 5. The press drain where water pressed out of washed textiles, for example by rollers or equivalent pressing mechanism, is discharged. Using standard bacterial culturing techniques, each of the water samples was used to seed nutrient media contained in two previously sterilized Petri dishes. One of these dishes was then incubated at 22⁰C for 72 hours whereas the other dish was incubated at 37⁰C for 48 hours. The number of colony forming units (CFU) were then counted for each dish. The results are as follows.

It will be appreciated that the significance of the two different incubation temperatures and periods is that microbes that contaminate the environment tend to proliferate at lower temperatures, such as room temperature, whereas pathogenic bacteria that can live within the body and cause disease tend to proliferate at temperatures closer to normal body temperatures. Of the two sets of results, therefore, the results for incubation at 37⁰C are the more significant as regards the efficacy of disinfection.

The results are disturbing as they are indicative that the current disinfection protocols for biologically contaminated textiles are not sufficiently rigorous to kill many pathogens.

The object of the present invention is to provide a method of disinfecting textile articles during a laundry process and a laundry preparation for use in such a process which improves the biocidal efficacy of the laundering process and which eliminates the need to use hydrogen peroxide as a separate bleaching product. It is an additional object to provide a method of disinfecting textile articles in a laundering process which reduces the quantity of water required in the laundry process and which produces less potentially environmentally damaging waste water.

According to a first aspect of the present invention there is provided a method of disinfecting textile articles during laundering wherein at least one wash cycle is followed by at least one rinse cycle and at least one laundry preparation is used, the laundry preparations used collectively comprising a terpene, a heat-activated bleach, and a mixture of an anti-microbial agent and a surfactant or an oil.

Preferably, during the wash cycle the water is maintained at a temperature between 40⁰C and 80⁰C inclusive. However, advantageously the water is maintained substantially at a temperature of 60⁰C.

Preferably also and in accordance with a second aspect of the present invention, a laundry preparation is provided for use in the method according to the first aspect of the present invention comprising a heat-activated bleach and in which a terpene and a mixture of an anti-microbial agent and a surfactant or an oil have been dispersed.

In a first embodiment, the laundry preparation is in powder form and the liquid terpene and a liquid mixture of the anti-microbial agent and the surfactant or oil have been dispersed throughout the powder.

In a second embodiment, the laundry preparation is in liquid form and the liquid terpene and a liquid mixture of the anti-microbial agent and the surfactant or oil are dispersed therein.

Alternatively, the laundry preparation comprises two components, the first component, which may be in liquid or powder form, comprising the terpene and the heat-activated bleach is used during at least one wash cycle - to -

and the second component comprising a liquid mixture of the antimicrobial preparation and said surfactant or oil is used during at least one rinse cycle. This means that the liquid mixture of the anti-microbial preparation and said surfactant or oil are used as a conditioner after the main laundering of the textiles has taken place.

Although the ingredients of the laundry preparation are individually known, most surprising results have been obtained in the disinfection of biologically contaminated textiles which challenge the requirements of the protocols currently in use. The degree of disinfection and cleaning during laundering is significantly better than conventional methods even at a lower wash temperature of 6o°C. It is believed that this is for three main reasons which when combined substantially improves the biocidal efficacy of the laundering process over conventional method and eliminates the need for separate bleaching cycle in addition to reducing the quantity of water required in the laundry process and at the same time producing less potentially environmentally damaging waste water.

First, the combination of the terpene and the heat-activated bleach produces excellent cleaning results on and stain removal from all forms of heavily soiled textile materials. Conventional laundry powders saponify greases and oils by using a high pH washing liquor. This, in combination with an elevated washing temperature and the mechanical action of the washing machine, removes oil and grease soiling by turning it into a soap that is then dissolved in the water. However, in the method of the present invention the terpene acts as a solvent to dissolve oil and grease soiling directly, the resulting solution then being dispersed and saponified within the washing liquor. This enables the laundry preparation to be formulated such that it has a greatly reduced alkalinity over conventional preparations so that pH neutralizers do not have to be used as part of the final rinsing process. Preferably, the laundry preparation contains up to 15% by weight a powdered detergent and up to 10% by weight a terpene. However, it has been found that the laundry preparation is effective if it contains the terpene at 5% by weight. This terpene may advantageously comprise d-limonene or dipentene or a mixture of d-limonene and dipentene, such as an equal mixture of d-limonene and dipentene. Terpenes are oily liquids and the desired liquid terpene is added to the powdered ingredients of the preparation after they have been dry-blended. The terpene is simply mixed into the blend to disperse the liquid into the dry powder ingredients. Preferably, the liquid terpene is sprayed into the blended powdered ingredients, which are then further blended to disperse the liquid.

Second, the inclusion of the heat-activated bleach within the preparation means that the bleaching becomes more effective as the temperature of the washing water increases. Preferably, the preparation comprises between up to 10% by weight a heat-activated bleach such as sodium percarbonate or sodium perborate. During the wash cycle the water is maintained at between 40⁰C and 80⁰C inclusive but advantageously the water is maintained at around 60⁰C. At this temperature the heat-activated bleach is at its most effective and as the bleaching takes place during the washing cycle a separate bleaching cycle at a cooler water temperature is not required. It will be appreciated that the heat-activated bleach also acts as an anti-microbial agent. Also, the use of a temperature substantially lower than 80⁰C means that significant savings can be made in the energy that would otherwise be used on heating the washing water. It is also possible to reuse the final rinse water, mixed with fresh water, directly in a prewash or soak cycle for the next batch of washing without having to cool it. This significantly reduces costs and the consumption of water. The lower temperature used in the method also has the significant advantage that thermal shock of the articles being washed can be more readily avoided.

Third, the mixture of an anti-microbial agent, and a surfactant or an oil together form an homogeneous solution or dispersion. The surfactant or oil tends to coat the surface of the textile material with a thin mono- molecular film within which dispersed pockets of the anti-microbial agent are held. The anti-microbial agent acts directly to kills microbes present on the surface of the textile and the mono-molecular film acts as a sacrificial layer that retains the anti-microbial in position to prevent further contamination occurring until the layer has worn away. This is particularly important when dealing with spore-forming bacteria as any spores retained within the textile fibres will be coated by the mono-molecular film, as will the surrounding fibres. If the spore germinates in due course during use of the textile, the anti-microbial dispersed within the mono-molecular layer will then act to kill the germinated cell. The laundry preparation therefore has a residual effect on germinating spore activity and later microbial contamination which lasts for a significant time after laundering of the textile. It has also been found that the combination of the terpene with the mixture of an anti-microbial agent, and a surfactant or an oil act in concert in two ways. First, the terpene dissolves dirt and coatings from around spores and bacteria in order that they can be acted on by the anti-microbial agent either or germination or directly. Second, spores tend to adhere to textile fibres via virtue of an outer sticky later formed around the outer coat of the spore. The terpene dissolves this stick}' coat and thereby makes the spore easier to wash out of the textile into the wash water where it can be completely coated by anti-microbial agent within the wash water. The mono- molecular film also conditions the textile and tends to repel dirt to reduce resoiling or recontamination of the article.

The outstanding results obtained by the method according to the invention can be gauged by a consideration of the results of the following field trials. These took place at Hospital A mentioned above using the same conventional industrial-size tunnel washing machine as in the previous tests and again the same tests were performed as previously but using a laundry preparation and method according to the present invention. The results are given the in the following table next to the results already detailed above for comparison purposes. _ q _

It can be seen that use of a method and laundry powder in accordance with the present invention virtually eliminates live microbes from the whole of the washing machine and therefore by implication from the textiles being washed. It was also found that use of the laundry preparation removed biofilms from the drains and feeds of the washing machine itself, hence the reduction in live bacterial colonies incubated from the main water feed inlet. This is particularly advantageous because in most industrial laundries handling biologically contaminated textile, the washing machines used have to be periodically taken out of use to be sterilized by removal of any biofilm build-up. Use of the laundry preparation according to the present invention will effectively make the washing machines self-sterilizing. These results are all the more outstanding when it is considered that an extremely small quantity of anti-microbial agent is actually used. This is explained in further detail below.

Preferably, the mixture of the anti-microbial agent and the surfactant or the oil dispersed within the powder contains the anti-microbial agent at less than 2% by weight. Preferably also, the mixture of the anti-microbial agent and the surfactant or the oil dispersed within the powder contains the surfactant or the oil at less than 4% by volume. Preferably, the surfactant is a siloxane, particularly a polysiloxane and especially either polydimethylhydroxysiloxane or polydimethylsiloxane.

A particularly advantageous mixture of an anti-microbial agent, and a surfactant or an oil for use in the laundry preparation of the present invention comprises ioo ppm cocoalkylch^'methylbenzylammonium, ioo ppm dodecyldimethylammonium chloride, 6o ppm bronopol, 50 ppm polymeric biguanide hydrochloride, and 180 ppm ethanol in water containing 1% by volume polydimethylhydroxysiloxane or polydimethylsiloxane.

In practice, a 0.5% solution of an anti-microbial agent and a surfactant in water, such as that proposed in the previous paragraph, is dispersed within the powdered constituents of the laundry preparation at a rate of 2 litres per 500 kg of powder. This means that the anti-microbial agent is present in the laundry preparation a quantities of less than 0.01% by weight. Such tiny quantities of anti-microbial agent are far lower than would otherwise be expected to produce the results detailed above. It also means that the impact of waste water from the laundry process is not environmentally damaging because both the quantity of anti-microbial agent discharged in the water is very small and the harmful microbes contained within it are by and large destroyed. Hence additional heat treatment of the waste water to kill any surviving microbes is not necessary.

It has been found that use of the anti-microbial agent and surfactant as aforesaid at dilutions of around 1/5000 in the rinsing water used during a final rinse cycle in a laundry process gives excellent results that far exceed expectations.

The anti-microbial agent used can be chosen according to the type of microbes that it is expected to encounter in the laundry process. Typically, therefore, the anti-microbial agent comprises at least one agent selected from amphoteric compounds, iodophores, phenolic compounds, quaternary ammonium compounds, hypochlorites and nitrogen based heterocyclic compounds.

Particularly preferred quaternary ammonium compounds include benzenethanaminiumn N-dodecyl-N, N-dimethylchloride, benzenethanaminiumn N-dodecyl-N, N-dimethyl-N-tetradecylchloride and benzyl-Ci2-C16-alkyldimethyl-ammoniumchloride.

Amphoteric compounds suitable for use as the anti-microbial agent include dodecyl beta-alanine, dodecyl beta-aminobutyric acid, dodecylamino-di (aminoethylamino) glycine and N (3-dodecylamino) propylglycine.

By the term "iodophores" is meant complexes of iodine or triodine with a carrier, such as a neutral polymer. The carrier typically increases the solubility of iodine in water, provides a sustained release of the iodine and reduces the equilibrium concentrations of free iodine. Suitable polymeric carriers from which iodophores can be prepared include polyvinylpyrrolidone., polyether glycols such as polyethylene glycols, polyvinyl alcohols, polyacrylates, polyamides, polyalkylenes and polysaccharides.

Suitable phenolic compounds include methyl, ethyl, butyl, halo and aryl substituted phenol. Preferred phenolic compounds include 2- phenylphenol, 2-benzyl-4-chlorophenol, 2-cyclopentanol-4-chlorophenol, 4- t-amylphenol, 4-t-butylphenol, 4-chloro-2-pentylphenol, 6-chloro-2- pentylphenol, p chloro-meta-xylenol, 2,4,4-trichloro-2-hydroxydiphenol, thymol, 2-ipropyl-3-methylphenol, chlorothymol, 3-methyl-4-chlorophenol, 2,6dichloro-4-n-alkyl phenols, 2,4-dichloro-meta-xylenol, 2, 4, 6- trichlorophenol and 2-benzyl-4-chlorophenol.

Suitable hypochlorites include chlorine dioxide and its precursors, as well as N, N-dichloro-4-carboxybenzenesulponamide (halazone), 1,3- dichloro5,5-dimethylhydantoin (halane) and various chloroisocyanuric acid derivatives.

Suitable nitrogen based heterocyclic compounds include pyridine derivatives, such as 4-pyridine carboxylic acid hydrazide, sodium 2pyridinethiol-l-oxide and bis- (2-pyridylthio) zinc-i, I-dioxide.

However, preferably, the anti-microbial agent is selected from benzenethanaminiumn N-dodecyl-N, N- dimethylchloride, benzenethanaminiumn N-dodecyl-N-N-dimethyl-Ntetradecylchloride, benzyl-Cte-Clό-alkyldimethyl-ammoniumchloride, 2phenyl phenol, 2-octyl- 2H-isothiazol-3-one, 5-chloro-2-methyl-2H isothiazol-3-one and 2-methyl- 2H-isothiazol-3-one.

It is a known that various types of bacteria form spores. Spores do not carry out any metabolic reactions and as a result they are especially suited to withstand severe environmental stress and are known to survive prolonged exposures to heat, drying, radiation and toxic chemicals such as antimicrobial agents. Although fungi, viruses and vegetative cells of pathogenic bacteria are sterilized within minutes at 70⁰C, many spores are not sterilized at this temperature and some can survive boiling for hours.

The outer coat of spores is made of a keratin-like protein which comprises as much as 80% by weight of the total protein of the spore. It is this protein coat which is responsible for the resistance of spores to chemical sterilizing agents. However, it is known that certain compounds can cause dormant bacterial spores to germinate and to convert into vegetative cells. When in this state, the vegetative cell can be killed by conventional antimicrobial agents.

Advantageously, therefore, the laundry preparation additionally comprises a spore germinating agent, typically at less than 0.1% by weight. Preferably, the spore germinating agent comprises at least one of L-alanine, L-arginine, L-phenylalanine, glutamic acid, inosine, sucrose, lactose, adenosine dLvaline, dL-cysteine, tyrosine, lactate, malate, guanine, methione, priopionate, formate, C02 I xanthosine, mannose, adenine, fumarate, oxaloacetate, quaternary ammonium compounds, dipicolinic acid, phosphate, and cobalt. However, advantageously the spore germinating agent comprises L-alanine because it acts over a wide spectrum of spore types.

The spore germinating agent can be added to the laundry preparation in several ways. If it is solid, such as a powder, it can be simply mixed into the other powdered constituents. Alternatively, it can be added as an aqueous solution or dispersion and diffused throughout the powder by adequate mixing.

In use, the spore germinating agent will start to act in the main wash as soon as the laundry preparation has been added to the water in the drum of the machine. Typically, a main wash cycle lasts for up to twelve minutes, which is sufficient time for the spore germinating agent to act to cause germination of a substantial number of the spores on the textiles being washed and within the washing water. These can then be killed by the antimicrobial agent within the laundry preparation.

Preferably, the laundry preparation comprises a degreasing emulsifier detergent such as, for example, nonyl phenol ethoxylate. Alternatively, the degreasing emulsifier detergent may comprise an alcohol ethoxylate.

The other ingredients of the powder preparation preferably comprise up to 70% by weight inorganic salts. For example, the preparation may comprise up to 33% by weight sodium carbonate and up to 40% sodium chloride. The sodium carbonate acts in known manner as a water softener and provides alkalinity when dissolved in the washing water. The sodium chloride is believed to act as a synergistic ionic accelerator which improves the action of the other ingredients. A builder, such as sodium tripolyphosphate, may also be added at up to 25% by weight.

A free-flow agent, such as sodium carboxymethylcellulose may also be added to the preparation.

Other optional ingredients may be added to the preparation to produce particular effects. Such ingredients comprise optical brightening agents, enzymes, bleaches, biocides, flame-retardant compounds, dirt repellents, and perfumes.

Various basic examples of a laundry preparation in accordance with the present invention will now be listed. In all cases, the preparation is manufactured by dry blending the powdered ingredients and by adding into the dry mix the liquid terpene component and the liquid anti-microbial agent and surfactant. The liquid constituents are preferably sprayed and mixed in to disperse the liquids throughout the dry powder ingredients. The proportions of the ingredients set forth in the examples are percentages by weight.

Example 1

Nonyl phenol ethoxylate (9 ETO) 4%

Sodium carboxymethyl cellulose 2%

Sodium percarbonate 8% Sodium carbonate 25.8 %

Sodium tripolyphosate 25%

Sodium chloride 30%

D-limonene 5%

Example 2

An alcohol ethoxylate 4%

Sodium carboxymethyl cellulose 2%

Sodium perborate 8% Sodium carbonate 22%

Sodium tripolyphosate 25%

Sodium chloride 33-7%

Dipentene 5%

Polysiloxane with trace antimicrobial agent as described above 0.2%

L-alanine 0.1%

Example 3

Nonyl phenol ethoxylate (9 ETO) 4%

Sodium carbonate 22%

Sodium percarbonate 896

Sodium tripolyphosate 25%

Sodium chloride 33-7%

Sodium carboxymethyl cellulose 2%

D-limonene 2.5%

Dipentene 2.5%

Polysiloxane with trace antimicrobial agent as described above 0.2%

L-alanine 0.1%

Example 4

Nonyl phenol ethoxylate (9 ETO) 4%

Sodium perborate 8%

Sodium carbonate 24.8%

Sodium tripolyphosate 24%

Sodium chloride 34°/o

Sodium carboxymethyl cellulose 2%

Nitrilotriacetic acid 3NA 2%

D-limonene 2.5%

Dipentene 2.5%

Polysiloxane with trace antimicrobial agent as described above 0.2% The above formulations can all be adjusted slightly to take into account the addition, in small quantities, of the additional ingredients such as optical brighteners, blue speckles, perfumes and other common additives to washing powders, for example by adjusting the proportion of sodium chloride in the composition.

It is important to store powdered laundry preparations in which the liquid terpene and liquid anti-microbial agent and surfactant components have been mixed in a way that reduces both vaporization of the terpene into the atmosphere and the absorption of moisture from the atmosphere by the terpenes and other ingredients of the preparation. Bags or sacks made from metallized polyester film are suitable for this purpose as they retain the terpene within the dry ingredients and prevent the passage of moisture therethrough.

In order that the efficiencies of the laundry preparation and method proposed herein can be appreciated, reference should be made to the following table wherein a typical laundry process for laundering heavily soiled hospital cottons in a washer-extractor type washing machine is described. A method in accordance with the present invention is described in the first table labelled Table iA and can be compared with a conventional laundry method as described in the table labelled Table lB. In both cases, the washing processes used the same type of articles and the same type of conventional industrial washing machine. In the tables, the time taken for the washing machine to perform various functions within one washing or rinse cycle of a washing processes is indicated, these functions being defined as follows.

Function Definition

Fill Filling a drum of the machine with water to desired level Heat Heating the water to a desired temperature, as indicated

Wash Tumbling the drum to cause a mechanical washing action after the indicated chemical additions have been added to the water to create an aqueous washing liquor

Drain Draining the aqueous washing liquor from the drum

Rinse Tumbling the drum to cause a mechanical rinsing action after any indicated chemical additions have been added to the water to create an aqueous rinsing liquor

Low Extract Spinning the drum at a relatively low rpm to extract washing liquor from the articles themselves

High Extract Spinning the drum at a higher rpm than that used in the Low Extract to extract all free washing liquor from the articles

The meanings of other terms used with the tables are as follows.

Low Dip: This refers to the level to which drum is filled with water. If a 'Low Dip' is used, the water level is relatively low so that the actual volume of water used is lower resulting in a higher concentration of any chemical additions thereto than with a 'High Dip' function and also a greater mechanical action on the articles when the drum is rotated during washing and rinsing functions.

High Dip: This also refers to the level to which drum is filled with water. If a 'High Dip' is used, the water level is higher than that in the 'Low Dip' level so that the actual volume of water used is greater resulting in a lower concentration of any chemical additions thereto than with a 'Low Dip' function and also a lower mechanical action on the articles when the drum is rotated during washing and rinsing functions.

Med Dip: This is an abbreviation for 'Medium Dip' and again refers to the level to which drum is filled with water. If a 'Med Dip' is used, the water level is higher than that in the 'Low Dip' level but greater than that in the 'High Dip' level with concomitant effects on the mechanical action and concentration of the chemical additions.

Chemical Additions: These comprise the laundry preparations that are used in the washing and rinsing functions. In the Tables iA the preparation is as defined herein in accordance with the invention. In the Tables lB, the detergents used are conventional industrial washing powders, which generally do not contain any significant terpene, heat-activated bleach or anti-microbial content. Other preparations comprise conventional laundry bleaches, such as hydrogen peroxide and conventional alkalinity neutralizers, named 'sour' in the trade. In both cases, the quantities stated are per kg of articles to be laundered.

Laundry Process for Hospital Soiled Cottons

TABLE lA - Method in Accordance with Present Invention

Total Wash Process Time - 45 minutes

Function Parameters Time Chemical Additions

Fill Med dip 3 g/kg Preparation formulated in accordance with the present method

Heat 4θ^ϋC 2

Wash 4

Drain 1

Fill Low dip 12 5 g/kg Preparation formulated in accordance with the present method

Heat 60⁰C 2

Wash 10

Drain 1

Low Extract 1

Fill High dip 3

Rinse 2

Drain 1

Low Extract 1

Fill High dip 3

Rinse 2

Drain 1

Low Extract 1

High Extract 8

TABLE 2B - Conventional Method

Total Wash Process Time - 63 minutes

Function Parameters Time Chemical Additions

Fill Low dip 1 5 g/kg Conventional detergent

5 ml/kg Bleach

Heat 40⁰C 2

Wash 5

Drain 1

Fill Low dip 1 10 g/kg Conventional detergent

5 ml/kg Degreasing emulsifier

Heat 80⁰C 5

Wash 12

Drain 1

Fill Med dip 2 5 ml/kg Bleach ..

Heat 60⁰C 3

Wash 6

Drain 1

Low Extract 1

Fill High dip 3

Rinse 2

Drain 1

Low Extract 1

Fill High dip 3 200 ml sour

Rinse 2

Drain 1

Low Extract 1

High Extract 8 In addition to the foregoing, it was found that using the laundry preparation and method according to the invention in a standard industrial tunnel-type washer (a continuous batch washer, i.e. CBW machine) enabled considerably less water to be used in the washing process. Conventionally in such machines around 9.7 litres of water are required per kg of textile materials whereas it was found that using the present invention only 5.6 litres per kg of textile materials was required. This leads to considerable savings as not only is less water used but less heat is required to raise the temperature of the water.

The laundry preparation and method according to the invention are particularly effective in the washing of heavily biologically soiled textiles at a temperature, 6o°C, which is considerably lower than the 80⁰C conventionally used for such articles. A maximum of only two wash cycles is carried out so that at least one complete wash cycle is omitted as compared to conventional methods. It will be appreciated that this is a considerable advantage to commercial laundries in particular because it means that they can achieve the same cleaning efficiency in a much shorter time and without having to heat the large quantities of water required for at least one wash cycle. The cost is therefore considerably reduced.

In addition, using the laundry preparation according to the present invention has the added advantage that at the final rinse stage of the washing process, the rinsing water is substantially ph neutral, i.e. ph 7, unlike many conventional laundry powders which tend to be still alkaline at this stage, typically between pH 8 and pH 9. This makes the method in accordance with the present invention ecologically friendly. A maximum of two rinse cycles is only every required and for these unheated water can be used.

It will be appreciated, therefore, that the laundry preparation and method in accordance with the present invention provides substantial savings to the benefit of the industrial laundry, the consumer and the environment. The benefits of the method can be summarized as follows. • Can be used with any conventional industrial washing machine

• Provides outstanding disinfection of biologically contaminated textiles without contamination of waste water • Self-cleans the washing machine itself by reducing the build-up of biofilms

• Water from the washing process does not have to be separately sterilized before being disposed of

• Provides substantial savings on water consumption, steam consumption, and wash dips

• The number of separate washing cycles are reduced increasing laundry throughput on a daily basis

• All types and classifications of laundry can be disinfected at a maximum of 6o°C, including heavily biologically contaminated textiles

• The savings include less wear and tear on boilers and machinery as the demand for steam is reduced by at least half

• The formulations detailed above for use in the method are very low in alkali • Thermal shock is avoided

Claims

1. A method of disinfecting textile articles during laundering wherein at least one wash cycle is followed by at least one rinse cycle and at least one laundry preparation is used, the laundry preparations used collectively comprising a terpene, a heat-activated bleach, and a mixture of an anti-microbial agent and a surfactant or an oil.

2. A method as claimed in Claim i, wherein during the wash cycle the water is maintained at a temperature between 40⁰C and 80⁰C inclusive.

3. A method as claimed in Claim 2, wherein during at least one wash cycles the water is maintained substantially at a temperature of 60⁰C.

4. A method as claimed in any of Claims 1 to 3, wherein the laundry preparation is in powder form, a liquid terpene and a liquid mixture of the anti-microbial agent and the surfactant or the oil having been dispersed throughout the power prior to use within the wash cycle.

5. A method as claimed in any of Claims 1 to 3, wherein a first laundry preparation comprising the terpene and the heat-activated bleach are used during at least one wash cycle and a second laundry preparation comprising a liquid mixture of the anti-microbial preparation and said surfactant or oil are used during at least one rinse cycle.

6. A laundry preparation for use in the method as claimed in any of Claims 1 to 4, comprising a heat-activated bleach and in which a terpene and a mixture of an anti-microbial agent and a surfactant or an oil have been dispersed.

7. A preparation as claimed in Claim 6, which is in powder form and in which the liquid terpene and a liquid mixture of the anti-microbial agent and the surfactant or oil have been dispersed throughout the powder.

8. A preparation as claimed in Claim 6, which comprises two components, the first component, which may be in liquid or powder form, comprising the terpene and the heat-activated bleach for use during at least one wash cycle, and the second component comprising a liquid mixture of the anti-microbial preparation and said surfactant or oil for use during at least one rinse cycle.

9. A preparation as claimed in Claim 6, which is in liquid form and in which the liquid terpene and a liquid mixture of the anti-microbial agent and the surfactant or oil are dispersed therein.

io. A preparation as claimed in any of Claims 6 to 8, which contains up to 15% by weight a powdered detergent and up to 10% by weight a terpene.

11. A preparation as claimed in any of Claims 6 to 10, which in total contains up to 5% by weight a terpene.

12. A preparation as claimed in any of Claims 6 to 11, wherein the terpene comprises d-limonene or dipentene or a mixture of d-limonene and dipentene.

13. A preparation as claimed in Claim 12, wherein the terpene comprises an equal mixture of d-limonene and dipentene.

14. A preparation as claimed in any of Claims 6 to 13, which in total comprises up to 10% by weight the heat-activated bleach.

15- A preparation as claimed in any of Claims 6 to 14, wherein the heat- activated bleach comprises sodium percarbonate and/or sodium perborate.

16. A preparation as claimed in any of Claims 6 to 15, wherein the mixture of the anti-microbial agent and the surfactant or the oil contains the anti-microbial agent at less than 2% by weight.

17. A preparation as claimed in any of Claims 6 to 15, wherein the mixture of the anti-microbial agent and the surfactant or the oil contains the surfactant or the oil at less than 4% by volume.

18. A preparation as claimed in any of Claims 6 to 17, wherein the surfactant or oil is a siloxane.

19. A preparation as claimed in Claim 18, wherein the siloxane is polydimethylhydroxysiloxane or polydimethylsiloxane.

20. A preparation as claimed in any of Claims 6 to 19, wherein the anti- microbial agent comprises at least one agent selected from amphoteric compounds, iodophores, phenolic compounds, quaternary ammonium compounds, hypochlorites and nitrogen based heterocyclic compounds.

21. A preparation as claimed in Claim 20, wherein the or each quaternary ammonium compound is selected from behzenethanaminiumn N- dodecyl-N, N-dimethylchloride, benzenethanaminiumn N-dodecyl-N, N- dimethyl-N-tetradecylchloride and benzyl-Ci2-CI6-alkyldimethyl- ammonium chloride.

22. A preparation as claimed in Claim 20, wherein the or each amphoteric compound is selected from dodecyl beta-alanine, dodecyl betaaminobutyric acid, dodecylamino-di (aminoethylamino) glycine and N- (3dodecylamino) propylglycine.

23. A preparation as claimed in Claim 20, wherein the or each iodophore is selected from a complex of iodine or triodine with polyvinylpyrrolidone, a polyether glycol, a polyvinyl alcohol, a polyacrylate, a polyamide, a polyalkylene and a polysaccharide.

24. A preparation as claimed in Claim 20, wherein the or each phenolic compound is selected from 2-phenylphenol, 2-benzyl-4chlorophenol,

2-cyclopentanol-4-chlorophenol, 4-t-amylphenol, 4-tbutylphenol, 4- chloro-2-pentylphenol, 6-chloro-2-pentylphenol, p-chlorometa- xylenol, 2,4,4-trichloro-2-hydroxydiphenol, thymol, 2-i-propyl- 3methylphenol, chlorothymol, 3-methyl-4-chlorophenol, 2,6- dichloro-4-nalkyl phenols, 2,4-dichloro-meta-xylenol, 2,4,6- trichlorophenol and 2benzyl-4-chlorophenol.

25. A preparation as claimed in Claim 20, wherein the or each hypochlorite is selected from chlorine dioxide or a precursor thereof, N, N-dichloro-4-carboxybenzenesulphonamide, 1,3-dichloro-

5,5dimethylhydantoin and a derivative of chloroisocyanuric acid.

26. A preparation as claimed in Claim 20, wherein the or each nitrogen based heterocyclic compound is selected from 4-pyridine carboxylic acid hydrazide, sodium 2-pyridinethiol and bis- (2pyridylthio) zinc-i, l-dioxide.

27. A preparation as claimed in any of Claims 6 to 19, wherein the antimicrobial agent is selected from benzenethanaminiumn N-dodecyl-N, N- dimethylchloride, benzenethanaminiumn N-dodecyl-N-N- dimethyl-Ntetradecylchloride, benzyl-Cl2-C16-alkyldimethyl- ammoniumchloride, 2phenyl phenol, 2-octyl-2H-isothiazol-3-one, 5- chloro-2-methyl-2H isothiazol-3-one and 2-methyl-2H-isothiazol-3- one.

28. A preparation as claimed in any of Claims 6 to 19, wherein the anti- microbial agent, comprises 100 ppm cocoalkyldimethylbenzylammonium, 100 ppm dodecyldimethylammonium chloride, 60 ppm bronopol, 50 ppm polymeric biguanide hydrochloride, and 1S0 ppm ethanol in water; and the siloxane or oil comprises polydimethylhydroxysiloxane or polydimethylsiloxane.

29. A preparation as claimed in any of Claims 6 to 8 or any of Claims 10 to 28 when dependent of Claim 7 or Claim 8, wherein a 0.5% solution of an anti-microbial agent and a polysiloxane in water, is dispersed within the powdered constituents of the laundry preparation at a rate of 2 litres per 500 kg of powder.

30. A preparation as claimed in any of Claims 6 to 29, which additionally comprises a spore germinating agent.

31. A preparation as claimed in Claim 30, wherein the spore germinating agent comprises at least one of L-alanine, L-arginine, L- phenylalanine, glutamic acid, inosine, sucrose, lactose, adenosine dLvaline, dL-cysteine, tyrosine, lactate, malate, guanine, methione, priopionate, formate, C02 I xanthosine, mannose, adenine, fumarate, oxaloacetate, quaternary ammonium compounds, dipicolinic acid, phosphate, and cobalt.

32. A preparation as claimed in Claim 30 or Claim 31, wherein the spore germinating agent comprises L-alanine.

33. A preparation as claimed in any of Claims 30 to 32, which comprises up to 0.1% by weight spore germinating agent.

34- A preparation as claimed in any of Claims 6 to 33, comprising a degreasing emulsifier in the form of a nonionic surfactant.

35. A preparation as claimed in Claim 34, wherein the nonionic surfactant is nonyl phenol ethoxylate or an alcohol ethoxylate.

36. A preparation as claimed in any of Claims 6 to 35, which comprises up to 70% by weight inorganic salts.

37. A preparation as claimed in any of Claims 6 to 36, which comprises up to 40% by weight sodium carbonate.

38. A preparation as claimed in any of Claims 6 to 8 or any of Claims 10 to 38 when dependent on Claim 7 or Claim 8, wherein the powder is bagged in bags or sacks comprised of a metallized polyester film.