US20140137339A1

US20140137339A1 - Method of sanitizing textile articles and the like

Info

Publication number: US20140137339A1
Application number: US14/087,585
Authority: US
Inventors: Richard John Stacey Burnet; Paul Parsons; Subhash Chander Anand; Karthick Kanchi Govarthanam; Subbiyan Rajendran
Original assignee: Aburnet Ltd
Current assignee: University of Bolton; Aburnet Ltd
Priority date: 2012-11-22
Filing date: 2013-11-22
Publication date: 2014-05-22
Also published as: DE102013223939A1; GB2510235A; GB201320624D0

Abstract

Provided herein is a method of removing hair from a textile article or the like. The method comprises providing a solid or liquid composition comprising sodium hydroxide, dispersing the solid or liquid concentrate in an aqueous medium that is contacted with the textile article or the like, such that the concentration of sodium hydroxide in the aqueous medium is 1-15% w/w, and maintaining the aqueous medium in contact with the textile article or the like at a temperature between 10° C. and 120° C. for a period of between 1 and 180 minutes. The sodium hydroxide causes dissolution of hair from the textile article. There is also provided a concentrate comprising sodium hydroxide used in such method. Such method is particularly useful in treating human hairwear, especially hairwear used in sanitary conditions, such as food production, and for pet products to which animal hair may adhere.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to GB 1221027.4 filed on Nov. 22, 2012 and GB 1314327.6 filed on Aug. 9, 2013, both of which are incorporated herein by reference in their entireties.

TECHNICAL BACKGROUND

This invention relates to a method of sanitizing textile articles and the like. In particular, this invention relates to a method for removing hair from items of workwear as part of a laundering process, as well as in other domestic sanitary applications. The invention may also be of particular utility in the removal of animal hair from textile articles and the like that are used by or in association with domestic pets or other animals.

BACKGROUND

In many environments, such as food preparation and medical establishments, it is important that high levels of hygiene are maintained. As part of maintaining appropriate hygiene levels, it is important to ensure that all clothing and other workwear worn by those working in such environments is clean and in good condition. High levels of hygiene are also desirable in a domestic environment particularly where pets or other animals are present. Normal laundering processes are appropriate for removing dirt and stains, but they may not effectively remove hair that has become attached to clothing and other garments during use.
Hair easily becomes caught on the surface or inside the structure of textiles. It is believed that this happens through two mechanisms: electrostatic and mechanical forces. Electrostatic forces exist between the positively charged amino acids in keratin (the protein which makes up hair), and the negatively charged functional groups in many textiles (e.g., the carboxylic acid groups in polyesters). Mechanical forces cause hair to become entrapped in textiles when a garment is worn or a textile item is in direct contact with hair. Movement of the garment or textile item against the hair causes individual hairs to be forced into the structure of the fabric. For example, the movement of a hat against a wearer's head, or of an arm cover against a wearer's arm, causes hairs to become lodged in the fabric structure of the hat or arm cover. Textiles can also become contaminated with hair through contact with other items. For example, if two items of workwear come into contact with each other or are washed together using conventional laundering processes, hair and other dirt can be transferred between the garments, thereby spreading contamination.
Because of this, the removal of hair from textiles is difficult. As a result, it is common for workwear to be disposed of after a single use, because there is no appropriate method for reliably removing all of the hair from a garment, and so maintaining an appropriate level of hygiene. The same problem is also found in domestic environments and commercial environments involving animals such as horse stables or veterinary surgeries where, for example, dog and/or cat hairs easily become caught in clothing, on furniture or carpets and on pet/animal bedding and accessories. The presence of large amounts of hair is a common cause of domestic washing machine breakdowns and the transfer of hairs from contaminated items to other non-contaminated items during the cleaning process is also highly undesirable.
There are a number of commonly used mechanical devices for removing hair from fabric. One such device is a roller with a sticky surface. As the sticky surface of the roller is rolled across the fabric, it sticks to hairs and draws them from the fabric. However, being very labor-intensive, such hand-held devices have limited application in environments in which large quantities of items need to be cleaned. In addition, rollers may not be effective in removing hairs that have become lodged within the structure of the fabric, making it impossible to ensure that all hairs have been removed. Similar problems are encountered with other commercially available mechanical devices for removing hairs, such as vacuum cleaners, which are sometimes specifically sold for removing (pet) hair.
Where it is important that all of the hair is removed from an item, e.g., due to a need to maintain a high level of hygiene, the difficulty in reliably removing all of the hair often results in items being thrown away and replaced after a single use. For example, in automotive paint spraying, food preparation, food processing and the packaging industry, hats and hairnets are often disposed of at the end of each day as they cannot be effectively cleaned for re-use. Particularly where large numbers of people require clean and hygienic workwear on a daily basis, such a practice is expensive and environmentally unfriendly. In the domestic environment, incomplete removal of hair when laundering items affects the efficiency of the cleaning process as hair left behind can necessitate additional washing machine cycles to remove residual hair or ultimately the need for additional servicing or replacement of the washing machine itself due to blockages caused by the build-up of hair. Such practices are expensive and environmentally unfriendly.

SUMMARY

There has now been devised an improved method of sanitizing textile articles and the like, which overcomes or substantially mitigates the above-mentioned and/or other problems associated with the prior art.
According to a first aspect of the invention, there is provided a method of sanitizing a textile article or the like, which method comprises providing a solid or liquid composition comprising sodium hydroxide; dispersing the solid or liquid composition in an aqueous medium that is contacted with the textile article or the like, such that the concentration of sodium hydroxide in the aqueous medium is 1-15% w/w; and maintaining the aqueous medium in contact with the textile article or the like at a temperature between 10° C. and 120° C. for a period of between 1 and 180 minutes; wherein the sodium hydroxide causes dissolution of hair from the textile article.
According to another aspect of the invention, a concentrated composition suitable for and intended to be dispersed in an aqueous medium is provided. The concentrated composition comprises sodium hydroxide at a concentration such that, when the concentrated composition is, in use, dispersed in an aqueous medium the sodium hydroxide is present at about 1% to about 15% w/w, wherein the concentrated composition is in the form of

- a) a liquid concentrate comprising sodium hydroxide at a concentration of about 20% to about 50% w/w put up in a container having a volume of about 0.3 to about 1.0 liter; or
- b) a solid concentrate comprising sodium hydroxide in an amount of about 10 to about 300 g in the form of a tablet or powder, which solid concentrate comprises sodium hydroxide at a concentration of at least about 60% w/w in combination with a carrier.

DETAILED DESCRIPTION

According to a first aspect of the invention, there is provided a method of sanitizing a textile article or the like, which method comprises providing a solid or liquid composition comprising sodium hydroxide; dispersing the solid or liquid composition in an aqueous medium that is contacted with the textile article or the like, such that the concentration of sodium hydroxide in the aqueous medium is 1-15% w/w; and maintaining the aqueous medium in contact with the textile article or the like at a temperature between 10° C. and 120° C. for a period of between 1 and 180 minutes; wherein the sodium hydroxide causes dissolution of hair from the textile article.
The method of the invention is advantageous primarily in that it may reliably remove hair from textile articles and the like, thereby enabling the re-use of items which would otherwise have been disposed of. In addition, this method may easily be used in situations where large numbers of items require cleaning in a relatively short space of time. This is particularly useful in industries which employ a large number of people, and so require a high number of clean items of workwear for staff on a daily basis. The ability to re-use items of clothing and workwear multiple times results in a significant cost saving, as well as reducing the environmental impact of the industry. Higher cost products offering better protection and comfort to the worker may become economical to use if they can be washed and re-used. The sodium hydroxide may remove all of the hair from the article by fully or partially dissolving the hair. One method by which the sodium hydroxide may work is by breaking the hydrogen and ionic bonds within the structure of the hair, resulting in a breakdown of the protein structure and dissolution of the hair. In addition, the method is advantageous in that it dissolves the hair rather than simply removing the hair from the textile product. Hair and in particular pet hair is known to be a cause of washing machine breakdown due to blockages which may lead to water leaks. Also, the transfer of unremoved hair from a contaminated item to clothing, etc. is highly undesirable. Furthermore, a second wash may be avoided as all the hair is removed and there is no requirement to wash remaining hair through the system. It will be appreciated that reducing the number of product washes is beneficial to the product life-time and also to the environment.
The textile article or the like to which the sodium hydroxide is applied in the method of the invention may be an item of workwear. Such items include items of apparel such as overalls, caps or other headwear, including hairnets, arm coverings and gloves, and overshoes etc. A preferred aspect of the invention concerns the treatment of headwear, particularly human headwear. By “textile” is meant, in the context of the present invention, any material consisting of a network of natural and/or artificial fibers, or any item made wholly or predominantly therefrom. Such items may also be other household or industrial items commonly made from fabric, e.g., furniture covers, pet bedding, other pet accessories, equestrian items including saddlecloths, blankets, girth straps, bandages, fly veils, or other item of horse wear, etc. Textiles may be woven, nonwoven (including spun-bonded, thermally bonded and melt-blown nonwovens) or knitted and may, for example, be manufactured from fibers of polyester, cotton, nylon, viscose, polypropylene or any other suitable material. A preferred aspect of the invention is the removal of pet hair, including horse hair, and thus the textiles to which this invention relates are particularly for use in the care of animals. The invention may also be applicable to the sanitizing of items of workwear that are manufactured from materials that are not “textiles”, e.g., plastics materials in sheet form or pet and equestrian grooming brushes and combs. The method as applied for equestrian use is a particular embodiment of the present invention. The invention may also be applicable for cleaning any items incorporating hook-and-loop fasteners (Velcro-type). Hair is particularly difficult to remove from such fasteners by known methods such as rollers with a sticky surface, conventional laundering etc. Plastics materials and other small items, such as brushes and combs, may be put in a bag and washed in a conventional laundry process.
Typically, the method of the present invention forms part of a laundering process, by which is meant a process for the cleaning of textiles. For example, a laundering process may be a process of washing using a machine or by hand, and may include additional processes, either before or after application of the sodium hydroxide.
The hair-dissolving chemical is sodium hydroxide. Additional active ingredients used for hair removal preparations, e.g., hair-dissolving chemicals, may also form part of the treatment according to the present invention, and may include thioglycolic acid and salts thereof, e.g., sodium thioglycolate or calcium thioglycolate.
Without wishing to be bound by theory, it is believed that the sodium hydroxide may function by disrupting disulfide bonds in the keratin of the hair. This action is valuable in the method of the invention as the hair is completely removed rather than separated from the product and therefore requires no further processing to remove the hair from the treatment system.
The use of sodium hydroxide is particularly advantageous as, apart from its effect on hair present in the articles being laundered, sodium hydroxide may also assist in the removal of dirt or other contaminants. This may reduce the amount of detergent or other ingredients that need to be used in the laundering process. Sodium hydroxide may also be used at relatively low concentrations and is, at least at those concentrations, safe and easy to use, not presenting any difficulties in handling. Sodium hydroxide is widely available in suitable forms and is inexpensive.
Other inorganic chemicals that may be suitable for use in the invention, in combination with the sodium hydroxide, include perborates, peroxides and cyanates, e.g., sodium perborate, calcium peroxide, hydrogen peroxide, potassium cyanate, or mixtures thereof.
Another class of hair-dissolving chemical that may be suitable for use in the invention, in combination with the sodium hydroxide, is enzymes that are capable of breaking down, and hence causing the dissolution of, hair. Such enzymes include proteases, in particular enzymes derived from Bacillus strains.
However, enzymes may be deactivated at the relatively high temperatures commonly used in domestic and industrial laundering processes, and at lower temperatures may act too slowly to be practicable. Enzymes may also be relatively costly, and the discharge of substantial concentrations of such materials may be undesirable from an environmental point of view.
The concentration of sodium hydroxide in the composition will vary, depending on the anticipated quantity of hair to be dissolved, the ratio of product (i.e., weight of articles) to liquor (i.e., the washing liquor comprising water, the sodium hydroxide and any hair-dissolving chemical and other laundry additives, for example detergent), the weight of the articles from which it is desired to remove the hair, the nature of the material from which the hair is to be removed, the temperature of the treatment and the time period of the treatment. The concentration of the sodium hydroxide used in the present treatment process is from 1 to 15% w/w, suitably up to 10% w/w, for example from 1 to 10% w/w. Particular ranges are 1.5 to 10% w/w, 2 to 10% w/w, 2.5 to 10% w/w, 3 to 10% w/w, 4 to 10% w/w and 5 to 10% w/w. The concentration may be greater than 1% w/w and less than 10% w/w. In practice, it may be convenient to have a maximum concentration of 5% w/w or less than 5% w/w, for example from 1 to 5% w/w, as greater values may cause the degradation of some materials, particularly delicate materials, during the sanitizing process. Thus, preferred ranges of the sodium hydroxide are in the range 1.5 to 5% w/w, 2 to 5% w/w, 2.5 to 5% w/w and 3 to 5% w/w. A more preferred concentration of the sodium hydroxide is from 2 to 4% w/w. In some circumstances, it may be desired that the concentration is, for instance from 1% up to about 4%, 3% or 2% w/w. Such concentrations have been found to be suitable, for instance under certain sanitizing conditions which may be dependent on the nature of the material in which case satisfactory results have been achieved at a concentration of 1% to 3% w/w, e.g., 1% w/w, 2% w/w or 3% w/w.
The composition comprising the sodium hydroxide will generally be a liquid composition, most commonly an aqueous solution. The composition may be manufactured and supplied to end-users in its final form, suitable for direct application. More commonly, however, the composition will be supplied as a solid or liquid concentrate, for dissolution in a solvent (e.g., water) in situ or prior to use. A solid concentrate may have the form of a bulk powder or a tablet and may be added to the process in this form or in the form of a sachet, a block, pellets or sewn items, e.g., a fabric sachet, containing such formats. Liquid concentrates may be supplied in the form of a bulk liquid or gel, or as a sachet, capsule or ampoule. Most commonly, a liquid concentrate will be supplied in a volume and concentration that is such as to provide the desired concentration of the sodium hydroxide in use, i.e., when the concentrate is added to a standard volume of water, e.g., the standard fill volume of a domestic or industrial washing machine.
In currently preferred embodiments, the sodium hydroxide is formulated as a concentrated aqueous solution of sodium hydroxide with a concentration of 20% to 50% w/w, more preferably 30 to 50% w/w or 35-45% w/w, most preferably around 40% w/w. In some circumstances, lower concentrations may be envisaged, such as 20 to 40% w/w, e.g., 25% to 35% w/w. The product may be put up in a container having a volume of 0.3-1.0 liter, e.g., from 0.4-0.8 liter or from 0.5-0.7 liter. Preferred are 500 ml liquid containers, multiples thereof, e.g., 1 liter, 5 liters etc., or smaller denominations thereof, e.g., 125 ml or 250 ml.
The amount of sodium hydroxide composition used in the treatment is generally dependent on the weight of the articles to be washed as well as the concentration of sodium hydroxide in the aqueous composition. The liquor (washing liquid (e.g., water) including treatment and laundry additives) may be varied to suit the product weight. Suitably, the product (kg)/liquor ratio is one in which 1 kg product is combined with up to 10 liters liquor, for example 1:1-10 parts by weight, preferably up to 7 liters liquor, for example 1:1-7 parts by weight, and more preferably up to 4 liters liquor, for example 1:1-4 parts by weight. Typical domestic washing machines wash 3-8 kg product with 5-20 liters water. In a preferred method according to the invention, most commonly 2-6 kg product is washed with 6-10 liters water in a domestic process. Typical industrial washing machines wash 100-200 kg product.
The sodium hydroxide may also be supplied in powder or tablet format in combination with a carrier and any other desired ingredients such as detergent and/or effervescent materials. Similarly, tablets, sachets and the like will be manufactured such that addition of one (or more) such units to the solvent gives the desired concentration of sodium hydroxide.
Alternatively, aliquots of a bulk composition, whether solid or liquid, may be measured into the solvent to yield a composition with the desired concentration of sodium hydroxide.
The sodium hydroxide may be added at any time during the laundering process. For example, the sodium hydroxide may be sprayed onto the textile prior to washing the item, it may be added as part of the washing process, or it may be applied to the item after washing. Preferably, the method comprises a one-bath process for laundering and hair removal, in which the items to be laundered are immersed in a bath containing the composition. Preferably, such a process is contained in the main wash of a laundry process. Alternatively, the method may include a pre-soak operation and/or a rinsing step. In the pre-soak operation, the article from which hair is to be removed is soaked prior to washing. The pre-soak operation may involve soaking the article in a solution containing the sodium hydroxide, in a solution containing a detergent, in water, or in any other suitable solution. Advantageously, the sodium hydroxide is added to the main wash cycle of the laundering device as this will allow the treatment of the sodium hydroxide, added at an appropriate concentration for hair to be dissolved from the articles (e.g., 1 to 15% w/w), to occur at elevated temperature (e.g., 30 to 120° C.) for a desired period of time (between 1 and 180 minutes). More usually, the treatment time in the main wash lasts between 1 and 85 minutes, more preferably between 1 and 30 minutes. In another method according to the present invention, the articles are treated with the hair-removing chemical by washing, followed by a rinsing procedure. Typically, up to four rinses, for example, one rinse, or preferably two or three rinses, may be carried out to remove any undesired residue. This procedure may be preferred where it is desired to wear an article subjected to the present treatment next to the skin.
Alternative methods of application of the composition to the items to be laundered may also be possible. For instance, the sodium hydroxide may be applied as a coating on the item, e.g., by means of an impregnated roller or an impregnated wipe, or by spraying.
The composition may be utilized at room temperature or at an elevated temperature. It is desired to treat the articles in question in the range between 10° C. and 120° C. Preferably, the composition is applied at, or raised to a temperature of up to 100° C., for example between 20° C. and 100° C. Convenient upper limits may be 94° C., 95° C., 96° C., 97° C., 98° C. or 99° C. Typically, the temperature may be in the range between 30° C. and 100° C. or between 30° C. and 90° C. For example, the temperature may be 40° C., 60° C., 70° C., 80° C. or 90° C. Conveniently, the sodium hydroxide-containing composition is applied in a laundering process in which the material carrying the hair is washed at a temperature of at least 40° C., 50° C., 60° C., 70° C. or 80° C., e.g., a temperature in the range 40 to 100° C., 50 to 100° C., 60 to 100° C., 70 to 100° C., 80 to 100° C. or 90 to 100° C. or a temperature in the range 40 to 90° C., 50 to 90° C., 60 to 90° C., 70 to 90° C. or 80 to 90° C.
It will be appreciated by one skilled in the art that the time for which it is necessary that the sodium hydroxide is in contact with the article will vary depending, for example, on the article to be cleaned, the concentration of sodium hydroxide or the temperature. The sodium hydroxide is applied for between 3 and 90 minutes. Preferably, the sodium hydroxide is in contact with the article for a sufficient time that substantially all of the hair on the article is dissolved. More preferably, the sodium hydroxide is applied for between 10 and 60 minutes, or between 30 and 60 minutes.
The nature of the fabric from which it is desired to remove hairs will also determine the treatment conditions. More robust materials, such as cotton, may be treated with higher concentrations of sodium hydroxide at a higher temperature for a shorter time, whereas delicate synthetic materials, such as polyesters and polyamides, may require to be washed for a longer time, for example 60 to 90 minutes, at a lower temperature for example, 30-70° C. In addition, a higher weight of product will generally require a higher concentration of sodium hydroxide and/or a higher temperature and/or a longer washing time in order to maintain the same efficiency in removal of the hair.
In the method of the invention, additional ingredients that facilitate or enhance the removal of hair, as well as the conventional cleaning of the items to be laundered, may also be applied.
Such additional ingredients include those that are conventionally used in washing powders and the like, and may include some or all of the following:

- a) one or more detergents;
- b) antimicrobial agents, which include antibacterial agents, antiviral agents and antifungal agents;
- c) fragrances;
- d) optical brighteners;
- e) anti-creasing agents;
- f) softening agents;
- g) fire retardants or flame proofing agents; and/or
- h) water repellents.

These additional ingredients may be applied to the items to be laundered separately from the sodium hydroxide. Alternatively, they may be included in the same composition as the sodium hydroxide and so are applied simultaneously with the sodium hydroxide. In the latter case, the additional ingredient(s) may be formulated with the sodium hydroxide in concentrated form, as described above.
Thus, according to a further aspect of the invention, there is provided a concentrated composition suitable for and intended to be dispersed in an aqueous medium, the concentrated composition comprising sodium hydroxide at a concentration such that, when the concentrated composition is, in use, dispersed in an aqueous medium the sodium hydroxide is present at 1-15% w/w, wherein the concentrated composition is in the form of

- a) a liquid concentrate comprising sodium hydroxide at a concentration of 20-50% w/w put up in a container having a volume of 0.3-1.0 liter; or
- b) a solid concentrate comprising sodium hydroxide in an amount of 10-300 g in the form of a tablet or powder comprising sodium hydroxide at a concentration of at least 60% w/w in combination with a carrier.

In currently preferred embodiments, the concentrated composition is an aqueous solution of sodium hydroxide with a concentration of 25% to 45% w/w, e.g., 30% to 45% w/w. The concentrated composition may be put up in a container having a volume of 0.3-1.0 liter, e.g. from 0.4-0.8 liter or from 0.5-0.7 liter.
The concentration of sodium hydroxide in the concentrated composition is preferably such that, when the concentrated composition is dispersed in the aqueous medium the concentration of the sodium hydroxide is less than 10% w/w, more commonly less than 5% w/w, for instance from 1% up to about 4%, 3% or 2% w/w, and most preferably 1% to 2% w/w, e.g. 1% w/w or 2% w/w.
The concentrated composition may alternatively be a solid concentrate. A solid concentrate may have the form of a bulk powder or pellets or the form of a tablet or block. The solid concentrate may suitably contain the sodium hydroxide in a concentration of 60-99%, preferably 60-95% w/w, more preferably 60-90% w/w. The solid concentrate may be added to water or may be added to the wash liquid in the desired number of units to provide the desired wash concentration, i.e., a wash concentration of 1-15% w/w. The carrier may comprise detergent and or effervescent materials as well as commonly used solid formulation ingredients.
One advantage of the invention is that by washing the hair-carrying materials, the articles do not need to be disposed of, such as disposal in land-fill sites. It is also desirable to launder the articles in an efficient way as possible to minimize the environmental impact. Treating a small quantity of small articles will allow treatment at a lower concentration and/or lower temperature and/or treatment time. However, a preferred cleaning process uses an optimized quantity of articles for the machine under consideration, such as industrial or domestic washing machines.
A further preferred process involves incorporating the hair-dissolving treatment during the main wash cycle as this is conducted at the elevated temperature for the period of time required for the present hair-dissolving process.
Preferred conditions present an optimized combination of temperature, concentration, ratio of product to liquor and treatment time. For any given concentration of sodium hydroxide, if the temperature is raised the treatment time may be reduced and vice versa. Desirably, the sodium hydroxide is used at a concentration in the range 1.5 to 5% w/w, preferably 2-4% w/w, and washing at a temperature greater than 50° C., especially 80-100° C., in a washing cycle which may typically take from 1 to 85 minutes, preferably between 1 and 60 minutes, more preferably between 1 and 30 minutes. In preferred embodiments the treatment period is between 5 and 60 minutes, especially between 5 and 30 minutes and most preferably between 10 and 30 minutes.
Preferred treatment conditions are a concentration of sodium hydroxide of from 1 to 10% w/w and a weight ratio of the articles to liquor (washing liquor) of 1:1-7 parts by weight wherein the main cycle wash is carried out at a temperature of between 50° C. to 100° C. for between 1 and 85 minutes. Especially preferred treatment conditions are a concentration of sodium hydroxide of from 1 to 5% w/w and a weight ratio of the articles to liquor of 1:1-4 parts by weight wherein the main cycle wash is carried out at a temperature of between 60° C. to 100° C. for between 1 and 30 minutes.
The concentrated composition may also comprise one or more additional ingredients selected from the group consisting of detergents, antimicrobial agents, fragrances, optical brighteners, anti-creasing agents, softening agents, fire retardants or flame proofing agents, and/or water repellents.
The invention will now be illustrated, by way of example only, with reference to the following Examples.

EXAMPLE 1

Use of Sodium Hydroxide to Dissolve Hair

Solutions of sodium hydroxide of concentrations between 2% and 10% were prepared by dissolving sodium hydroxide in water at room temperature, e.g., a 2% solution was prepared by dissolving 2 g of sodium hydroxide in 100 ml of water at room temperature.
Defined quantities of hair were immersed into the sodium hydroxide solutions and the action of the reagent was observed at different temperatures and over different time periods. The results can be seen in Table 1.

TABLE 1

The effect of sodium hydroxide on hair.

Temperature	Time	2% NaOH	5% NaOH	10% NaOH

40° C.	15 min	Hair softened	Hair softened	Starts to
		and loss of hair	and loss of hair	disintegrate
		colour	colour
	30 min	Hair softened	Starts to	30% partial
		and loss of hair	disintegrate	disintegration
		colour
	45 min	Hair softened	50% partial	30% partial
		and loss of hair	disintegration	disintegration
		colour
	60 min	Hair softened	70% partial	50% partial
		and loss of hair	disintegration	disintegration
		colour
60° C.	15 min	All colour lost.	50% partial	80% partial
		Minor partial	disintegration	disintegration
		disintegration.
	30 min	60% partial	90% partial	90% partial
		disintegration	disintegration	disintegration
			after stirring	after stirring
	45 min	100%	100%	90% partial
		dissolution	dissolution	disintegration
				after stirring
	60 min	100%	100%	95% dissolution
		dissolution	dissolution
80° C.	15 min	90% dissolution	95% dissolution	95% dissolution
		without stirring
	30 min	95% dissolution	95% dissolution	95% dissolution
	45 min	100%	100%	100%
		dissolution	dissolution with	dissolution
			residue
	60 min	100%	100%	100%
		dissolution	dissolution	with dissolution
			residue

It was found that under a number of conditions, for example, when immersed in 2% sodium hydroxide at 60° C. for 45 min, hair dissolves completely.
Controlled experiments were then carried out on 100% polyester hairnets which contained human hair. The hairnets were immersed in 2% sodium hydroxide at 60° C. for 45 min. After this time had elapsed the hairnets were inspected, and all human hair was observed to have been dissolved from the fabric.
Further experiments, following the procedure outlined above, were then carried out using lower concentrations of sodium hydroxide and a temperature of 60° C. The results can be seen in Table 2.

TABLE 2

The effect of low concentrations of sodium hydroxide on hair

Time	0.5% NaOH	1% NaOH	1.5% NaOH

15 min	No visible change	Changes observed in	Swelling of hair
		hair (curling)
30 min	No visible change	Swelling of hair	Loss of hair colour
45 min	Swelling of hair	75% disintegration	100% dissolution
60 min	Swelling of hair	90% dissolution	—

It was found that complete dissolution of hair is obtained by the use of a solution containing 1.5% sodium hydroxide at 60° C. for 45 min. Additionally, it was found that a 1% solution of sodium hydroxide did not completely dissolve hair after 60 min, but complete dissolution with this concentration was achieved after 75 min.

EXAMPLES 2 TO 4

Formulations for Domestic Use


	Concentration (w/w)

	Example 2	Example 3	Example 4

Water	57.25%	59.5%	50.5%
Sodium Hydroxide	32%	32%	41%
Detergent	8%	8%	8%
Non-staining dye	0.5%	0.5%	0.5%

The formulation may be supplied in a container with a volume of approximately 600 ml, such that when introduced to the drum of a domestic washing machine, the composition is diluted between 16- and 32-fold to give an operational concentration of sodium hydroxide between 1 and 2% w/w.

EXAMPLE 5 AND 6

Formulations for Industrial Use


		Concentration (w/w)

	Example 5	Example 6

Water	67%	58.25%
Sodium Hydroxide	32%	41%
Urea	0.5%	0.25%
Disinfectant	0.5%	0.5%

EXAMPLE 7

8 kg Product weight domestic washing machine
6 litre of water in main wash,
2 kg of product weight


		Grams
		required
	Concentration	for 6 Litre
Chemicals	(w/w)	m/c

Sodium	2%	120 g
Hydroxide
Effervescent	Appropriate to	Example for
Chemical	wash	light staining
such as	requirements	1%/60 g
Sodium	heavy/light soil
BiCarbonate
(Detergent)
Non	Dependant on	Example for
Staining	strength of	weak
Dye-L81021	colour	colouration
		0.0005%/3 g

EXAMPLE 8

8 kg Product weight domestic washing machine
6 litre of water in main wash
3 kg of product weight


		Grams
		required
	Concentration	for 6 Litre
Chemicals	(w/w)	m/c

Sodium	3%	180 g
Hydroxide
Effervescent	Appropriate to	Example
Chemical	wash	for light
such as	requirements	staining
Sodium	heavy/light soil	1%/60 g
BiCarbonate
(Detergent)
Non	Dependant on	Example
Staining	strength of	for weak
Dye-L81021	colour	colouration
		0.0005%/3 g

EXAMPLE 9

8 kg Product weight domestic washing machine
10 litre of water in main wash
5 kg of product weight


	Concentration	Quantities for
Chemicals	(w/w)	500 ml Bottle

Sodium	3%	300 g
Hydroxide
Urea	0.25%	2.5 g
Non Staining	Dependant on	Example for
Dye	strength of	weak
L81021	colour	colouration
Chromat.Blue.		0.0005%/3 g

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.

Claims

What is claimed is:

1. A method of removing hair from a textile article, the method comprising:

providing a solid or liquid composition comprising sodium hydroxide;

dispersing the solid or liquid composition in an aqueous medium that is contacted with the textile article, such that a concentration of sodium hydroxide in the aqueous medium is from about 1% to about 15% w/w; and

maintaining the aqueous medium in contact with the textile article at a temperature between about 10° C. and about 120° C. for a period of between about 1 and about 180 minutes, wherein the sodium hydroxide causes dissolution of hair from the textile article.

2. The method according to claim 1, wherein the concentration of sodium hydroxide in the aqueous medium is about 1 to about 10% w/w; wherein the aqueous medium is maintained in contact with the textile article or the like at a temperature between about 30° C. to about 90° C. for a period of between about 3 to about 90 minutes.

3. The method according to claim 1, wherein the textile article to which the sodium hydroxide is applied is an item of workwear.

4. The method according to claim 1, wherein the textile article to which the sodium hydroxide is applied is a carpet, an item of furniture, an item of clothing, a pet accessory, an equestrian item or item of horsewear, or an item incorporating a hook-and-loop fastener.

5. The method according to claim 4, wherein the hair to be removed is pet hair, including horse hair.

6. The method according to claim 1, wherein the method forms part of a laundering process.

7. The method according to claim 1, comprising one or more hair-dissolving chemicals selected from the group consisting of the group selected from thioglycolic acid or a salt thereof and enzymes.

8. The method according to claim 1, wherein the concentration of sodium hydroxide is from about 1% w/w to about 5% w/w.

9. The method according to claim 1, wherein the composition comprising the sodium hydroxide is an aqueous liquid or gel composition.

10. The method according to claim 1, wherein the composition is supplied as a solid or liquid concentrate.

11. The method according to claim 6, wherein the method comprises a one bath process.

12. The method according to claim 6, wherein the sodium hydroxide is contacted with the articles during the main wash of a laundry process.

13. The method according to claim 12, carried out in the presence of a washing liquor aqueous medium wherein the ratio of articles to the washing liquor aqueous medium is in the range from about 1:1 to about 1:10 parts by weight.

14. The method according to claim 6, wherein the method comprises a pre-soak operation.

15. The method according to claim 1, wherein the composition comprising the sodium hydroxide is applied as a spray or as a coating on the article.

16. The method according to claim 1, wherein the aqueous medium containing the sodium hydroxide chemical is maintained at a temperature of from about 70° C. to about 100° C.

17. The method according to claim 16, wherein the aqueous medium containing the sodium hydroxide chemical is maintained at a temperature of from about 80° C. to about 100° C.

18. The method according to claim 1, wherein the sodium hydroxide is in contact with the article for between about 1 minute and about 30 minutes.

19. The method according to claim 1, wherein one or more additional ingredients are applied to the textile article, the one or more additional ingredients being selected from the group consisting of detergents, antimicrobial agents, fragrances, optical brighteners, anti-creasing agents, softening agents, fire retardants, flame proofing agents, and water repellents.

20. A concentrated composition suitable for and intended to be dispersed in an aqueous medium, the concentrated composition comprising:

sodium hydroxide at a concentration such that, when the concentrated composition is, in use, dispersed in an aqueous medium the sodium hydroxide is present at about 1% to about 15% w/w, wherein the concentrated composition is in the form of

a) a liquid concentrate comprising sodium hydroxide at a concentration of about 20% to about 50% w/w put up in a container having a volume of about 0.3 to about 1.0 liter; or

b) a solid concentrate comprising sodium hydroxide in an amount of about 10 to about 300 g in the form of a tablet or powder, which solid concentrate comprises sodium hydroxide at a concentration of at least about 60% w/w in combination with a carrier.