EP0678126A1 - Method and apparatus for cleaning textile fibres or other materials - Google Patents

Abstract

The invention relates to a method for cleaning textile fibres or other materials which comprises contacting said textile fibres or other materials with a finely-divided particulate material, the particles of which have a capacity to adsorb oil, grease and other contaminants. The invention also relates to a method for controlling parasitic infestations in animals involving the finely-divided particulate material and an apparatus for cleaning textile fibres or other materials.

Description

METHOD AND APPARATUS FOR CLEANING TEXTILE FIBRES

OR OTHER MATERIALS

This invention relates to a method and apparatus for cleaning textile fibres or other materials which may be contaminated by oils, waxes, grease and similar impurities. If these oily contaminants are accompanied by dirt and similar inorganic substances, and suint, these are also largely removed along with the oils and greases by the cleaning method and apparatus.

The process of wool scouring is used in both the woollen and worsted systems. About 14% of the wool sold in Australia is destined for the woollen system, much of it from the edges of the fleece (bellies, pieces, locks and crutchings). This wool is traditionally cleaned in water containing soap or non-ionic detergent to remove grease, dirt and suint and is also often carbonised to remove vegetable matter such as grass seeds.

About 86% of Australia's greasy wool enters the worsted system, which gives a higher-valued product from the longer fibres in the bulk of the fleece. After scouring, the clean wool is subjected to the complex and expensive steps of carding and combing. These processes remove shorter fibres and vegetable matter and result in the wool emerging as a continuous web of parallel fibres ("tops") ready for drawing, doubling and finally spinning on the worsted system. The operations of backwashing and dyeing (if required) can also be performed at various stages, for example, after carding, after spinning, etc.

The worsted system nas evolved specifically to cater for the longer fibres (50 to 75 mm) and the attributes they can impart to the finished products.

For modern high-speed carding, combing and spinning operations it is important for textile fibres to be as clean as possible, for example, less than 0.4% grease content. Any residual grease will hold residual dirt and degraded protein, including inner-root-sheath protein. These residual contaminants can have a deleterious effect on processing and on the quality of the final product. Such deleterious effects are exaggerated in the production of superfine yarns for light weight fabrics.

On the other hand, larger amounts of residual grease can be tolerated in the hand spinning and cottage industries, where a small percentage of residual grease on the fibres prior to spinning is in fact desirable.

Environmental constraints associated with the cleaning of natural textile fibres are likely to increase in coming years, both within Australia and overseas. There is thus an incentive to devise new processes which can overcome the environmental problems associated with traditional aαueous scouring.

Cleaning with dry powders has long been practised, for example, talcum powder followed by beating to clean a fur coat; bran, pollard or kieselgiώr to clean a dog's pelt; and powder application followed by vacuum cleaning to remove stains from a carpet.

More recently, a wool scouring process has been described in which melted grease is sponged from wool fibres by an absorbent powder (G.H. Robertson and J.P.Morgan., Text. Chem. Col., 1973, 5, 98-101). The absorbent powder is expanded-bead polystyrene, a resilient, non-friable and non-biodegradable plastic. The powder particles are deformable so that the particles which are large (150 to 350 microns) relative to the wool fibre diameter (15 to 30 microns) maybe employed. The process involves applying the powder to greasy wool which has been "opened" by hand carding. The wool and powder mixture is then heated to liquefy the grease and the powder particles are compressed to increase the fibre-particle contacts. This process is claimed to produce a fibre which contains about 0.5% grease and about 4.5% suint when given twenty 80 psi compressions at a temperature above about 66 °C.

Other dry powder wool scouring processes have also been investigated or advocated in the past, but none has been adopted by the textile industry. These have included processes using gypsum (United States Patent Specifications No.s 1323185, 1218573, 1323641, 1449613 and 1449826 and British Patent Specification No. 359559), kieselguhr (Australian Patent Specification No.11862/33), aluminium silicate (AustraUan Patent Specification No. 18917/34) and cereal flours (United States Patent Specification Nos. 2982676 and 2979782).

A requirement accordingly exists for a dry powder cleaning process for wool and other textile fibres which avoids or minimises the environmental and cost problems of earlier processes, is effective in cleaning the fibres to the requisite degree, whether for subsequent use in high speed machinery or in simpler small-scale and hand spinning operations, both in the woollen and worsted fields, and which leads to minimum fibre breakage during subsequent mechanical processing of the wool fibres.

According to one aspect of the present invention there is provided a method for cleaning textile fibres or other materials which comprises contacting said textile fibres or other materials with a finely-divided particulate material, the particles of which have a capacity to adsorb oil, grease and other contaminants.

The present invention also p^rovides a cleaning agent which comprises a finely- divided p.articulate material, the particles of which have a capacity to adsorb oil, grease and other contaminants.

The particles of the particulate material may have a hydrophobic surface layer, such as, for example, an oleophilic surface layer which has a capacity to adsorb oil, grease and other contaminants.

Preferably, the textile fibres or other materials are contacted at a temperature at or above the softening/liquefaction point of the grease contaminants.

The particulate material is preferably in powder form. Suitable materials include inorganic oxides such as anhydrous alumina (aluminium oxide) for example alpha and gamma forms of anhydrous alumina, magnesia (magnesium oxide) for example EMAG 75, titanium dioxide (titania or nitile), zirconium dioxide (zirconia) or silicon dioxide (silica); inorganic hydrous oxides such as hydrated alumina for example aluminium hydroxide; inorganic hydroxides such as anhydrous or hydrated alumina (aluminium hydroxide); inorganic carbonates such as calcium carbonate (chalk) for exar- ie Omya 40, magnesium carbonate (magnesite), calcium magnesium carbonate (dolomite) or strontium carbonate; inorganic silicates such as calcium silicate (wollastonite), sodium aluminium silicate (sodalite), aluminium silicate (kaolinite) for example Microwhite Kaolin and Kaolin K10, magnesium silicate (talc), zirconium silicate (zircon) or more complex natural or synthetic zeolites (aluminosilicates) for example spent cracking catalyst from the oil refining industry; inorganic phosphates such as calcium phosphate, magnesium phosphate or zirconium phosphate; inorganic sulfates such as calcium sulfate, strontium sulfate, barium sulfate or zinc sulfate; carbon for example carbon black; and sulfur for example powdered sulfur; or mixtures thereof. Magnesia, chalk, kaolin and alumina are preferred inorganic materials for use in the method of the invention.

A useful material for the first-stage degreasing of raw wool is anhydrous alumina including both the smelter grade material used for the electrowinning of aluminium which is mainly a mixture of the alpha and gamma forms and the chromatographic grade material which is mainly the gamma form. Alumina can also be used for a second-stage cleaning. If the amount of residual alumina then present on the fibres is thought to possibly present an unwanted mild abrasive action during subsequent carding, gilling and combing, further cleaning may be performed with a softer material such as chalk (with or without a fatty acid surface layer), talc or kaolinite. These latter materials displace die fine "sandy" alumina particles and their soft and somewhat "oily" nature means that any residual material will then provide a lubricating action for the fibres and assist to reduce both mechanical wear and also fibre breakage during the subsequent mechanical operations.

In most cases, total cleaning with magnesia, chalk or kaolinite is preferred. Alumina can be preferred when the powder is to be recovered for subsequent re-use by combustion of the adsorbed grease in a furnace. Chalk and magnesia are most preferred when it is intended to apply the used material for horticultural or agricultural purposes. These purposes can include use as a fertiliser and soil conditioner, as a feed stock in vermiculture and as an additive to poultry or to fish food used in aquaculture. A more preferred material, on the basis both of cost and efficiency, is kaolin, with second-stage cleaning (if required) using fresh kaolin, magnesite, alumina or magnesia. A particularly- preferred material, both for first-stage and second-stage cleaning, is EMAG 75, a finely- powdered magnesia obtained by purification and decomposition of naturally-occurring low-iron magnesite.

It has also been found that for various applications, including the degreasing of wool, the method can be made even more efficient if additives such as anhydrous sodium bicarbonate, sodium carbonate, slaked lime, magnesia, or various organic compounds such as anionic, non-ionic or cationic polymers and detergents and organic solvents such as eucalyptus oil which can assist to soften the grease are added in a small amounts, such as, for example, about 1% to about 20%, to the primary cleaning agent such as alumina, chalk, kaolin or similar materials.

For example, sodium bicarbonate is an effective additive to chalk, alumina and kaolinite, while magnesia is a particularly effective additive to these materials. The inorganic additives can also play a useful role if the grease adsorbed to, for example, alumina, is to be subsequendy destroyed by a high-temperature incineration step. If any chloro-organics are present in the grease, for example, from certain pesticide residues, the hydrochloric acid which might otherwise be generated can be converted by a high- temperature reaction with the additive to yield sodium, calcium or magnesium chloride. The same is true for any sulfur-containing compounds which otherwise might give rise to free sulfuric acid and which could now be converted into the metal sulfate.

Organic additives to assist in the method may include cationic polymers such as a polymer of ethyleneimine for example Corcat P18, Corcat P150 or Corcat P600 or an acrylic polymer having amino or quaternary ammonium side chains such as the Ultrion, Optimer or Alfloc cationic flocculants marketed by d e Nalco Chemical Company; cationic detergents such as cetyltrimethylammonium chloride; non-ionic detergents and polymers such as sucrose esters of long-chain fatty acids, alkylaryl ethers of polyethylene glycol) or carbowaxes for example Polyethyleneglycol 6000; and anionic detergents such as sodium or ammonium dodecyl sulf ates, dodecylbenzene sulfonates or sodium salts of fatty acids (common soap) or of sulfated oils for example sulf ated castor oil.

The particulate material may have a surface coating comprising a long-chain fatty acid, such as, for example, stearic acid, oleic acid or palmitic acid, or mixtures thereof which are readily available from the saponification of animal fats. A coated chalk or magnetite powder may be made by grinding die calcium or magnesium carbonate to the desired particle size and dien passing it into a heated chamber to which is also admitted an appropriate quantity of vaporised fatty acid or fatty acid mixture. By chemical reaction on the surface (which liberates an equivalent amount of carbon dioxide), die surface of the inorganic material becomes coated widi a layer of chemically- bound fatty acid. This renders diat particle non-wettable by water, but easily wettable by hydrophobic materials such as oils and grease.

Materials of this kind are available commercially, e.g., "Omyacarb 2T¹, which is calcium carbonate coated widi stearate. This product which is available from Omya Southern Pty. Ltd. is extensively used as a filler for synthetic plastics such as PVC. Its hydrophobic nature allows, in contrast to calcium carbonate itself, ready mixing widi the molten plastic and also wid plasticisers such as dioctyl phd alate. These Omyacarb 2T particles have an average diameter of 2.7 micron, a surface area of 3.3 m² per gram, an oil absorption of 15g per lOOg, .and a dioctyl phdialate absorption of 18g per lOOg.

Products similar to Omyacarb 2T maybe produced using mixtures of long-chain fatty acids obtained from tallow, vegetable oils, fats and waxes, and from od er long chain carboxylic acids. Metal carbonates other than calcium carbonate may also be used, for example, magnesium carbonate, strontium carbonate, barium carbonate and dolomite, which is a natural molecular mixture of calcium and magnesium carbonates.

The paniculate material is preferably added to the textile fibres or other materials in a ratio of about 0.4:1 to about 3:1, respectively, more preferably a ratio of about 0.5:1, respectively. It will be appreciated diat this ratio will depend on d e amount of grease and oil present, the type of particulate material used, d e nature of the textile fibres or other materials to be cleaned and whedier the method is used as a first or subsequent cleaning step.

A principal application of the method of d e invention is in die cleaning of raw wool from sheep. However, it will be appreciated that the method can also be readily extended to die cleaning of other natural fibres such as animal fibres for example goat hair (mohair or cashmere), llama hair (alpaca), camel hair, horse hair and rabbit fur; insect-derived fibres for example silk; vegetable fibres for example cotton, flax, rhamie, jute, manila, sisal and phormium; and cellulose fibres generally, including fibres destined for die manufacture of paper and otiier felts as distinct from yarns. Synthetic fibres which have become soiled with grease or dirt subsequent to manufacture may also be cleaned by die method of die invention. Other natural and artificial fibres for the subsequent production of woollen, worsted and otiier textile yarns may also ^a used in the method of the invention.

The method of the invention is also applicable to the removal of grease, fats, dirt and other impurities from keratinous materials such as skins, hides and leather, m particular, the method is useful in the preliminary cleaning of sheepskins produced in the abattoir, prior to fellmongering or subsequent tanning of the skin to make leather.

In the known processes, the skins are often heavily salted to inhibit bacterial or fungal attack prior to transport to the fellmongery and tannery. On subsequent washing, tangling and felting of die wool fibres can occur, so that the value of the wool obtained after fellmongering is reduced.

It has been found diat skins from freshly-killed animals, together with the attached wool or hair, can be cleaned and degreased using the method of d e invention. The hides can be tumbled in a horizontal closed banel widi a powder such as chalk, kaolinite or magnesia and tiien separated from the used powder. The process can be repeated if necessary until the desired level of cleanliness is achieved. Alternatively, the skins can be attached by small hooks to a flexible open-mesh belt and conveyed into, through and out of a fluidised bed of powder held at about 65 ^βC to about 70 ^βC, widi each skin remaining in the bed for a sufficient time, for example, about 10 to about 20 minutes, for cleaning to occur. In these processes, grease is taken up from the skins as well as from the wool or hair and in many cases no further treatment (such as salting of die hides) is needed prior to tanning. Commercial apparatus for establishment of a pulsed, heated, fluidised bed of suitable size is readily available.

The method of die invention may also be used in die removal of oils and grease from the surfaces of other materials such as metallic, ceramic, wooden, plastic and cellulosic materials. In these applications of the method, the colour of the powder used is often of lesser significance than is the case for wool and otiier textile fibres, where white or near-white powders are advantageous, and d e use of coloured zeolites, kaolinites, carbon black and powdered sulfur, or mixtures thereof with sodium bicarbonate or magnesia, becomes feasible.

Another application lies in the use of the particulate materials of the invention in die control of parasitic infestations in animals such as lice, mites or fly strike in sheep.

According to another aspect of the present invention there is provided a mediod for controlling parasitic infestations in animals which comprises applying the finely-divided particulate material defined above to the afflicted, or affliction-prone areas of the animal in order to absorb and remove grease, dirt, suint, and dags and thereby reduce d e likelihood of infestation.

The particulate material is preferably applied in a jet of air to the afflicted, or affliction-prone areas of the animal. Chalk, kaolin and alumina are preferred particulate materials, and magnesia, either alone or in admixture with chalk, kaolin or alumina, is especially preferred for these purposes.

The disposal of traditional aqueous wool-scouring effluent by means of sewerage treatment such as the use of settling ponds, anaerobic and aerobic digestion, and die subsequent disposal of sludge and waste water, can be an expensive operation and one having many environmental concerns. The main option at some present scouring operations in Europe, Japan and die United States of America is sewerage treatment in an activated sludge plant, followed in some cases by expensive incineration of the sludge and tertiary treatment of the waste water. The disposal of effluent tiirough a grass filtration or lagoonal sewerage system, even when the residual sludge can be stored on site, requires large areas of land.

The metiiod of the invention is advantageous in diat a range of options is available for disposal or recycling of the used material, now significantiy contaminated wid grease. These options will vary according to d e particular powder used, but generally will include recycling the used material for further use, disposal of the used solid material in a land fill or sewerage treatment plant, and in particular, the conversion of the used material into other products (wid or without recovery of the initial powder) or sale of the used powder, with its grease, into a new market. The latter processes include d e recovery of part or all of the wool wax, recovery of the powder or modified powder for reuse in the cleaning method or in otiier applications, and die use of the powder plus grease in various agricultural and horticultural operations.

In the case of chalk, magnesite and magnesia in particular, the bulk of the used cleaning agent, containing the grease, suint and dirt, may be retuπied to the land as a highly effective fertiliser. This is particularly the case when the cleaning method is carried out in country locations in association with or close to agricultural or horticultural operations. Chalk, magnesite and magnesia loaded with wool grease are very attractive and useful fertilisers and soil conditioners for somewhat acidic soils, which occur widely in Australia and otiier parts of the world.

Soil acidity is becoming a major problem in agriculture, resulting in nutrient deficiencies and aluminium toxicity to plants, possibly affecting as much as 40% of the world's arable land (Huag, A. (1984) Cr . Rev. Plant Sci. 1, 345-373).

The presence of up to 20% or more of wool grease renders ti ese powders initially non-wettable in water; when added to soil, biodegradation of the adsorbed grease occurs and this assists the subsequent dissolution of the inorganic material. The used powders mentioned still behave as non-sticky free-flowing materials. The grease- laden powder can if required be converted by known methods into prill form, where each prill is 3-5mm in diameter and convenient for fertiliser application.

Another attractive agricultural enterprise for the disposal of solid waste from this method is the large-scale raising of worms (vermiculture), using species such as Lwnbricius rubella, Eisenia foetida, Perionyx excavata and various species of the genera Aporrectodea, Micmscolex and AUolobophora. The resulting worm casts and egg capsules are a high-value fertiliser and soil conditioner. Worms are readily able to consume wool grease along with solids such as challc, magnesite, magnesia, kaolinite and alumina and the other powders used in this cleaning method.

When alumina, silica, kaolinite, magnesia, titania, zirconia, silica, wollastonite, sodalite, kaolinite, zeolites, inorganic phosphates and sulfates, zircon, talc, or mixtures thereof are the preferred materials, the used material may be readily passed through a furnace (e.g., using fluidised bed combustion) to burn off the adsorbed grease. In some cases the recovered powder can be used again for die purpose of this invention. In the case of chalk, magnesite and dolomite, or mixtures thereof, the used powder may be incinerated to give saleable lime, magnesia or a mixture respectively. In all these cases, the adsorbed grease constitutes part of the fuel required for the incineration process.

Heating these same grease-laden powders under high vacuum also makes possible a distillation of the grease and its condensation in highly pure form. Boiling the greasy powders in water leads to wetting of the powder and d e release of some grease which floats to the surface of the water and can be skimmed off. If a cationic polymer (of the kinds marketed by Allied Colloids, Nalco, or SNF (through ICI Australia)) is added to an aqueous suspension of the greasy solids and air passed into the mixture, substantial amounts of the grease can be recovered by a flotation process.

Disposal in a conventional land fill is also feasible, as is also destruction of the grease in an anaerobic or aerobic digester. Such biodigestion allows recovery of the powder for reuse or sale.

Alternatively, the used material can be extracted with an organic solvent or can be washed in an aqueous solution of soap or detergent. Grease can be recovered by evaporation of the solvent or centrifugation of the aqueous liquor. These operations on grease-laden powder are much easier and cheaper to perform than the corresponding operations on the original greasy wool. The degreased solid can be recovered and reused.

When carbon black is used as a cleaning powder, d e carbon plus grease can be used as a fuel.

In all cases where the material is treated to allow for re-use of the powder for the purpose of this invention, the recovered material can, if required, be then separated from any adventitious clay, sand or dirt which may now be present as a result of the presence of such materials in the raw wool or other starting material, for example by air classification in a cyclone separator, by use of a shaking table or other suitable known means.

According to another aspect of the present invention there is provided a method for cleaning textile fibres or other materials which comprises the steps of: a) placing the textile fibres or other materials in an opening means, said opening means being arranged to open the textile fibres or other materials so that they can be readily coated with the particulate material defined above; b) heating the textile fibres or other materials; c) applying the particulate material to the opened textile fibres or other materials before or after step b); d) allowing the coated open textile fibres or other materials to cool; and e) separating the particulate material from the textile fibres or other materials. In step a), the textile fibres or other materials to be cleaned can be opened using machinery such as a "Step Cleaner", "Superior Cleaner" or "Ultra Cleaner", a battering Willow, a "continuous acting shaking machine" such as an HDB Shaker, or a "Fearnought" Opener.

In step e), the particulate material may be removed by subjecting the textile fibres or other materials to a succession of one or more processes using tumbling, opening or beating machinery such as those mentioned in step a) above or carding or gilling processes. The fibres or other materials are preferably subjected to multiple opening/carding processes to ensure complete separation of used particulate material from the cleaned textile fibres or other materials.

The method is particularly suitable for cleaning animal fibres such as raw wool, goat hair, llama hair (alpaca), camel hair, horse hair and rabbit fur. When animal fibres are to be cleaned, they are advantageously heated to a temperature at or above the softening/liquefication point of the grease contaminants.

Where the cleaning method is used to reduce the grease level down to about 1 to about 5% and the residual powder to about 1 to about 3%, with the intention that a final aqueous cleaning will still be applied (albeit at lower cost and widi reduced effluent disposal problems), it has been found that centrifugation of such aqueous cleaning liquors (after settling out of any suspended solids) yields a much superior wool grease (lanoline) product than would have been obtained from that wool had die initial cleaning method been omitted. This is because the cleaning method first removes photo- degraded lanoline from die outer surfaces of the greasy wool fibres, with the residual lanoline removed in any final detergent wash being of higher quality.

In the cashmere industry, the cleaning of the raw product and d e separation of down from guard hairs are processes of considerable difficulty and expense. In particular, aqueous detergent washing of the shorn fleeces can lead to considerable entanglement of the very fine cashmere fibres, with substantial loss of value due to fibre breakage in subsequent separation of down from guard hair, carding or similar operations used to separate the guard hairs. It has been found that cleaning of raw cashmere by the method of the invention leads to rapid spontaneous "opening" of the fleece, without felting or fibre entanglement, so that the subsequent physical separation of wool and hairs is greatly facilitated, and can be done at much higher speeds of operation than in the case of fleeces washed and prepared in a conventional manner.

Similarly, mohair (from Angora goats) responds dramatically to gentle cleaning by the method of the invention. As the small amount of grease present on the fibres transfers to the surface of the powder, the locks of mohair "open up" spontaneously as with cashmere, and direct carding is then a simple operation.

The cleaning agents of the invention has been shown to be efficacious not only in removing grease from textile fibres and from skins and hides, but also for the cleaning of a wide range of metal parts (which can be oily from machining), of ceramic objects, of plastic materials and indeed the cleaning of any solid surface contaminated widi oils, fats, waxes or grease.

Naturally, the types of equipment used for contacting the oily or greasy objects with powder and then removing the cleaning agent from such materials or objects will often be quite different from those used for the cleaning of skins, hides and textile fibres, but the principles remain the same. In particular, the application of cleaning agents of the invention in a jet of compressed air to a greasy surface, with a subsequent clean-air jet being used to remove any residual material, is one means of carrying out the method of the invention. Magnesia, alumina and kaolin are preferred powders for this "sand blasting" type of operation. A second widely-applicable method is to pass the greasy metal, ceramic, plastic, wooden or other objects continuously through a fluidised bed of powder heated to the appropriate temperature, as outiined above for the degreasing of abattoir skins. Various methods are available for fixing the objects to be cleaned to a moving open-mesh belt or container.

It has further been found that in certain cases of minimal contamination by vegetable fault, the wool after powder cleaning, gilling and optionally an aqueous back- washing, can be put directiy through a combing operation without necessity to card die wool. This has substantial advantages, since conventional carding often leads to fibre breakage, with loss of value. Even if carding after powdering is required for efficient separation of grease and powder, the lubricating nature of the powders employed means that minimal damage occurs to the fibre during such operation, in contrast to the situation of carding following aqueous scouring.

According to a further aspect of the present invention there is provided an apparatus for cleaning textile fibres or other materials comprising a first container arranged to receive a quantity of textile fibres or other materials which are to be cleaned, said first container having opposed top and bottom walls formed with a plurality of apertures, said first container being housed witiiin a second container so that an inorganic material introduced in a top portion of said second container will pass through the top wall of the first container, through the textile fibres or other materials contained in d e first container and through the bottom wall of the first container.

Preferably, the apparatus also includes means to circulate air and suspended inorganic material within the first and second containers.

The apparatus may also include means to vibrate the first container within the second container.

According to a still further aspect of the present invention there is provided an apparatus for cleaning textile fibres or other materials comprising an outer vessel containing an inner vessel, said vessels being arranged for rotation about their longitudinal axis, said inner vessel being arranged to receive a quantity of textile fibres or other materials which are to be cleaned, said inner vessel being arranged to be substantially sealed so that a particulate material can be inserted in die inner vessel and die inner vessel rotated so as to distribute the particulate material to the textile fibres or other materials, said inner vessel being arranged to be removable from said outer vessel and said outer vessel having a circumferential wall formed from a material having a plurality of apertures therein such that the textile fibres or other material can be contained in d e outer vessel while allowing used particulate material to fall through the apertures.

Preferably, the apparatus is contained in a sealed housing.

According to a still further aspect of the present invention there is provided an apparatus for cleaning textile fibres or other materials comprising a first barrel arranged for rotation about its longitudinal axis, said first barrel being angled such that textile fibres or other materials inserted in die first barrel at an input end gravitate when the first barrel is rotated to an output end and wherein the first barrel is heated.

Embodiments of the apparatus of invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a schematic cross-sectional front view of an apparatus suitable for cleaning 4-5 kg of wool at a time;

Figure 2 is a side view of the inner and outer cylindrical vessels of the apparatus shown in Figure 1;

Figure 3 illustrates a side view of an apparatus suitable for the commercial cleaning of wool; and

Figure 4 is an end view of the apparatus shown in Figure 3.

Figures 1 and 2 illustrate an apparatus 10 suitable for cleaning a small amount of wool (e.g., 4-5 Kg) or other goods. The apparatus 10 is likely to have application only in the cottage or craft industry, and also for small scale tests in further developing the technology by controlled experimentation. In the following description it will be assumed that raw wool is being cleaned.

The apparatus 10 is arranged to tumble the wool with a cleaning agent in powder form. The apparatus 10 comprises a cabinet or external housing 11 in which is mounted a double cylindrical vessel arrangement. This arrangement comprises an outer cylindrical vessel 12 having circumferential wall made of mesh and a first end which is closed by an end plate 14. End plate 14 is formed with a narrow circular groove 15 in the side face directed inwardly of the outer cylindrical vessel 12. This groove is arranged to receive in a close fit the inner end portion of an inner cylindrical vessel 18 which is arranged to be coaxially mounted within the outer cylinder 12. In operation, the open circular end of the inner cylindrical vessel 18 presses firmly against the bottom of the groove 15 in the end plate 14 of the outer cylindrical vessel 12 and thereby is sealed against loss of powder during the cleaning cycle.

For this scale of apparatus to handle 4-5 Kg wool at a time, the inner cylindrical vessel 18 is suitably 1.5m in length and lm in diameter, with all other measurements in proportion. A smaller version suitable for experimental work on a 300- 500g scale has an inner cylindrical vessel 600mm long and 560mm in diameter.

The inner cylindrical vessel 18 has a single shelf or "paddle" 40 running down its length which protrudes into the cylinder for a distance equal to about one third of die diameter of die cylindrical vessel, i.e., 300-350mm. This paddle 40 serves to tumble together the powder and d e wool fibres as the vessel is slowly rotated. A typical speed of rotation is between 10 and 20 rpm, with the contents of the vessel being heated to 65- 75° by a stream of hot air passing into and through the cabinet 11 and around the cylindrical assembly. The outside of the cabinet is lagged to conserve heat.

The end plate 14 of die outer cylindrical vessel 12 is welded to a shaft 22 which passes through a ball race assembly 23 in the wall of the cabinet 11 and continues to a gear train and electric motor 20. The gear train allows adjustment of the speed of rotation of the cylindrical vessels.

The near end of the outer cylindrical vessel 12 is welded to a circular plate or rim 24 to which are attached three bolts set equidistantly around the circumference. These bolts locate into holes in a similar circular rim 26 which is welded to die near end of the inner cylindrical vessel 18. A cover plate or lid 28 fits in turn over the three bolts and can in this way be fixed tightiy to the end of the cylindrical assembly so as to seal it against loss of powder and other materials during the cleaning operation. When cleaning is judged complete die hot air supply is shut off and rotation stopped.

The inner cylindrical vessel 18 consists of light weight metal such that when cleaning is finished and die outer cover plate 28 removed, die inner cylindrical vessel 18 can be easily withdrawn. At the same time the wool plus the bulk of the used powder can be pushed forward into the outer cylindrical vessel 12. With the inner cylindrical vessel 18 nearly removed, any remaining powder can be brushed into the outer cylindrical vessel 12 and die inner cylindrical vessel 18 can then be fully withdrawn and set aside.

A tumbling device is then clipped into place along the inside length of the outer cylindrical vessel 12. This device consists of a set of smooth rods each 300mm in length and 60mm apart fixed to a bar which can be slotted into a groove placed along the length of the cylinder 12. For ease of fixing, the outer cylindrical vessel 12 is first rotated so that the cleaned wool and used powder are at the bottom and d e groove is at the top and hence clear of all the wool and powdei. The cover plate 28 is then replaced to again seal the assembly and rotation is started to assist the separation of used powder from the cleaned wool fibres. A tumbling time of two minutes is usually sufficient.

The wool can then be withdrawn by hand, allowed to cool to room temperature and stored pending further processing. Before carding and/or gilling or direct hand spinning, die wool can, if required, be further "depowdered" by passing it through a step cleaner as used in the cotton industry, or through a machine such as a battering willow, a continuous-acting shaking machine or a fine wool opener, these machines being well known to those skilled in textile industry technologies.

The used powder which collects at the bottom 19 of the housing 11 can be withdrawn from time to time. A screw maybe provided at the bottom 19 of the housing 11 to convey the used powder to a storage or disposal location. A door 13 is fitted to the cabinet opposite the open end of the cylinder assembly. This door is closed while heating and cleaning is in progress and also during the depowdering cycle.

In all apparatus of this kind it is useful to arrange for dust extraction apparatus to operate at key points where powder could escape into the general working environment so that any powder which might otherwise become a health hazard is entrained in an air stream and delivered to a bag filter.

Figure 3 illustrates an apparatus 50 suitable for use in the commercial cleaning of wool fleeces. The apparatus 50 is arranged to tumble the raw wool with a dry cleaning powder as the wool and powder travel along the length of a cylindrical barrel 52 of approximately l-2m in diameter and approximately 5-15m in length. The cylindrical barrel 52 is fitted with a single paddle 54 which serves to lift and tumble the wool and powder as the barrel 52 rotates.

The barrel 52 is mounted on two sets of rollers 55A and 55B and is set at an angle such that fleeces placed in d e barrel 52 at the higher input end 52A will gravitate towards die lower output end 52B as the barrel rotates and tumbling occurs. The barrel 52 is heated directiy on its external surface by a set of gas jets 56 placed between the two sets of rollers and which can be controlled by a tiiermostat mounted inside die barrel 52.

Two separate feed hoppers for raw wool 60A and powder 60B are provided at d e input end, and a discharge hopper 60C to hold die wool at the output end.

From this discharge hopper 60C the wool can be delivered to a second barrel which functions like a trommel used in die mining industry. Like the first barrel 52 the second barrel is fitted wid a single paddle to tumble the wool. The sides of die second barrel are of open meshwork with apertures of about 5-lOmm. The apertures can retain the wool but allow the used powder to fall away into a cabinet which surrounds die second barrel and has sloping sides so that the powder concentrates at the bottom from which it can be removed continuously or intermittently by means of a screw. In use, the wool is first opened by means of a battering willow, a fine wool opener or similar machine and placed in die feed hopper 60A. Rotation of the barrel 52 is started and the gas jets are ignited to bring die barrel 52 to about 80°. Wool and powder are then fed in at a controlled rate and the gas jets adjusted by d e thermostat inside the barrel 52 so that the wool and powder at a given point along the barrel 52 reach a temperature of around 65-75°. The angle of the barrel 52, the rate of rotation, and the rate of heating can all adjusted so d at any particular portion of wool first reaches the desired temperature and then spends a further 5-20 minutes in the barrel 52 before being discharged into d e exit hopper 60C. The rate of rotation is typically between 5 and 15 rpm, with preference for the lower speeds so as to minimise any possible tangling of the wool. The middle section of the barrel 52 is constructed from a number of interlocking identical sections, each l-2m in length so that the overall length of the barrel 52 can be increased or decreased as needed depending on the rate of feed of the wool, the powder being employed, and die grease and dirt content of the material being cleaned.

The first barrel 52 is contained within a room or large cabinet which can be lagged to reduce heat losses and from which the combustion gases from the burners are exhausted to atmosphere. Alternatively the exhaust gases can be used to preheat the wool stocks which are being "opened" prior to being loaded into the feed hopper 60A.

Variations are possible in the introduction of the powder to the wool. Pre-used powder Pl can be introduced with the raw wool and fresh powder P introduced further down die barrel. Or alternatively a fresh powder P can be first mixed with the raw wool and a different powder Q introduced further down the barrel. Both P and/or Q can be pure powders or mixtures. In general, principles of countercurrent flow of wool and powder are employed if relevant, and heat exchangers are used where possible to ensure maximum use of the heat energy delivered by the burners.

However, in most cases it is sufficient to introduce clean powder with the raw wool since most of the grease is not removed from the fibre until the powder is shaken out in the "final depowdering" stage, which may follow the preliminary depowdering in the second, open mesh cylinder 62. Where such further depowdering is needed following the removal of "free" powder in the second cylinder, the wool can be passed through a step cleaner, a battering willow or fine wool opener or the like, prior to carding and/ or gilling.

The method of the invention is further described in and illustrated by the following Examples. These Examples are not to be construed as limiting the invention in any way.

In the Examples, the following wool samples were used:

Type of Wool Grease and Dirt % Yield % Suint % (wool + moisture)

DG1 18.7 1.7 79.6 merino, 21 microns

AWC wool 16.9 19.1 64.0 merino, very dirty and discoloured

Corrl 11.7 3.9 84.4 corriedale

TB1 9.0 1.0 90.0 caipet wool

DG4 19 1 80 merino, 22.6 microns, staple length, 98mm

The experiments described in the Examples were conducted in die apparatus as hereinbefore described and shown in Figures 1 and 2, with an inner (cleaning) barrel of length 840mm and diameter 560mm. This apparatus was convenient for treating wool samples from 100-500g in size.

Reference will also be made in the Examples to the following abbreviations:

SGA - smelter grade alumina as supplied by Queensland Alumina Ltd.; BDH - laboratory grade of alumina especially prepared for chromatography and obtained from BDH;

MWK - Microwhite Kaolin;

K10 - second variety of kaolin from Commercial Minerals Ltd;

Kaolin - kaolin sample from Weipa supplied by Comalco Ltd.;

Mag - finely ground sample of Magnesite FL20, a cryptocrystalline magnesite available from Queensland Metals Corporation. All the powdered material was less than 1mm, with very much fine material present down to low micron sizes;

4C30 - 4C-30 MgO (magnesia) product from Enviromag (Marketing) Pty Ltd;

EMAG - EMAG 75 a calcined magnesia product from Enviromag; and

OM-1, OM-1T, OM-2, OM-2T and OM-40 - Omyacarb products (calcium carbonate, chalk) from Omya Southern Pty Ltd. The numbers give an indication of average particle size in microns. The suffix T indicates that the chalk sample has been exposed to die vapour of a long-chain fatty acid such as stearic acid, which treatment results in the particles acquiring a surface coating of hydrocarbon chains, rendering them non-wettable by water but readily wettable by oils and grease.

The following inorganic materials are used in the experiments described in Example 1.6 below:

Ml - mixture of EMAG (10%) in OM-40 M2 - mixture of EMAG (20%) in OM-40 M3 - mixture of EMAG (10%) in SGA M4 - mixture of EMAG (10%) in K10 M5 - mixture of EMAG (20%) in K10 M6 - mixture of EMAG (15%) in Mag

Ul - once-used sample of Om-40 which had been previously used to clean DG4 wool at a 3:1 ratio. Example l

G = grease; D = "dirt", i.e., residual inorganic materials.

In each case, the result quoted is the average of two separate analyses.

After cleaning with powder for the times stated, the wool was tumbled in the "depowdering" barrel for two minutes to separate as much "free" powder as possible. The wool was then carded on a small commercial carding engine with a feed tray about 600mm wide and a main swift and working rollers about 1000 mm in width. This proved to be an ideal machine for removing the last of the powder from the cleaned wool. In most cases a second carding of the first sliver resulted in only a small further lowering of the residual grease and powder content.

The results are separated into six categories:

(1.1) Challc; (1.2) Magnesite; (1.3) Magnesia; (1.4) Alumina; (1.5) Kaolin, (1.6)

Mixtures and Used Inorganic Materials.

(1.1) Chalk

Wool Wt (g) Pwdr Wt (g) Temp Time Sample G % D °C (min) No.

AWC 250 Om-2 1000 64 5 1-1 0.8 9.0

AWC 250 Om-2 500 67 5 1-2 2.6 7.3

AWC 100 Om-40 300 75 30

Card twice 1-17B 1.8 3.8

AWC 100 Om-40 300 75 10

Card twice 1-18B 2.3 3.9

AWC 100 Om-40 300 75 5

Card twice 1-19B 2.5 4.5

A 45g sample of 19B was then cleaned again with 5g only of EMAG (MgO), then carded again 1-19C 1.2 3.3

AWC 100 Om-40 300 73

Card twice 1-20B 2.9 6.0

Corrl 250 Om-1 750 80 5 61-14AC 1.5 4.6 DG1 250 Om-1 750 78 5 61-18AM 2.0 8.4 AWC 250 OM-40 750 75 5 61-20A 1.8 5.0 Treat again, 1:1 ratio 61-20B2 1.4 1.5

DG4 100 Om-40 300 70 1-25A 3.5 4.2

Card twice 1-25B 3.0 2.6

DG4 100 Om-40 300 70 1-28A 2.4 3.0

Card twice 1-28B 1.9 1.3

(1.2) Magnesite

Wool Wt (g) Pwdr Wt (g) Temp Time Sample G% D% °C (min) No. AWC 100 Mag 300 71 5 1-13A 3.5 4.9

Repeat the cleaning at 1.5 ratio of powder to wool: first carding 1-13B 2.4 3.1 second carding 1-13C 1.6 2.8

AWC 100 Mag 300 73 10 1-14A 3.5 4.8

Card second time 1-14B 2.8 3.2

Take 1-14B and clean again with SGA at 73 °C, using 0.5 ratio 1-14C 2.0 2.3

(1.3) Magnesia

Wool Wt Pwdr Wt (g) Temp Time Sample G % D **>

(g) °C (min) No.

AWC 100 4C30 300 70 5 1-21A 1.5 1.0 card twice 1-21B 1.2 0.6

AWC 100 EMAG 300 73 10 1-22A 0.4 1.9 card twice 1-22B <0.1 <0.1

AWC 100 EMAG 300 73 5 1-23A 0.7 1.6 card twice 1-23B <0.1 <0.1

DG4 100 EMAG 300 70 10 1-24A 0.4 0.9 card twice 1-24B 0.2 1.1

DG4 100 EMAG 300 70 5 1-27A 0.7 0.9 card twice 1-27B 0.8 0.2

DG4 35 EMAG 35 30 10 1-29B 7.5 2.1 (1.4) Alumina

Wool Wt (g) Pwdr Wt(g) Temp Time Sample G % D % °C (min) No.

Corr 200 SGA 600 73 5 1-3 1.3 1.3 DG1 250 SGA 750 74 1-4 A 2.6 1.7 card twice 1-4B 1.7 .05 card third time 1-4D 0.9 0.5

AWC 250 SGA 750 71 1-5 1.5 4.2 ird twice 1-5B 2.3 0.8

AWC 100 SGA 300 67 1-9B 3.6 3.0

(carded twice)

This product was then cleaned again with SGA at 1:1 ratio and again carded twice: 1-11B 1.8 2.8

TB1 10 BDH 300 65 15* 61-10A 1.0 3.7 repeat treatment, ratio 1:1 61-10B 0.6 6.9

Corrl 250 BDH 750 68 5 61-16AC 2.1 4.1

DG1 100 BDH 200 70 15* 61-19A 6.3 3.7

(1.5) Kaolin

Wool t (g) Pwdr Wt (g) Temp Time Sample G % D % (min) (min) No.

AWC 250 MWK 750 74 5 1-6A 0.7 3.1

AWC 100 MWK 200 72 5 1-39B 0.3 2.1

AWC 100 MWK 100 71 5 1-38B 1.9 2.2

AWC 250 K10 750 75 5 61-22A 0.4 1.9 card twice 61-22B <0.1 <0.2

AWC 100 K10 200 71 5 1-36B 1.5 1.8

AWC 100 K10 100 70 5 1-37B 2.6 1.7

DG4 100 K10 300 70 10 1-26A 1.5 4.8 card twice 1-26B 1.2 3.0

DG1 10 kaolin 300 65 20* 61-8A 2.9 5.5

Treat product again with kaolin, 2:1 ratio 61-8B 1.3 2.8

TB1 10 kaolin 300 65 18* 61-9A 1.7 2.1 treat again with kaolin, 1:1 ratio 61-9B 2.0 0.9

AWC 250 K10 750 75 5 61-22A 0.4 1.9

(1.6) Mixtures and Used Inorganic Materials

Wool Wt (g) Pwdr Wt (g) Temp Time Sample G % O ^eι °C (min) No.

DG4 500 Ml 1000 68 20 61-62A 1.2 _.0

DG4 500 M2 500 70 30 61-63A 0.4 0.8

DG4 500 M3 1000 72 25 61-64A 0.5 0.5

DG4 250 M4 500 65 30 61-65A 0.3 0.8

DG4 250 M5 250 70 25 61-66A 0.1 0.3

DG4 250 M6 250 72 20 61-67A 0.7 0.9

DG4 500 Ul 1500 70 10 1-45A 3.1 2.2

Example 2

A 50g sample of AWC wool was held loosely in an open wire mesh container and subjected to an air jet containing entrained Omyacarb 2T powder from a spray gun. The compressor used was a small commercial unit (10 cubit, per min.), and the jet of powder could be directed onto bare skin without harm. The wool was then hand carded. Only a trace of residual powder was found in the sample and the measured grease content was 2.6%.

Example 3

Example 2 was repeated using DG1 wool and EMAG powder. The residual grease content after hand carding was 0.3%, the residual powder was 0.2%.

Example 4

Used powders from the various experiments described in Examples 1.1 to 1.5, namely samples of used chalk, magnesite, magnesia, alumina and kaolin, and also various samples of used OM-1, OM-IT, OM-2 and Qm-2T were extracted with different organic solvents such as methylene dichloride, ethanol, acetone, light petroleum, trichlorethylene, perchlorethylene and eucalyptus oil. In all cases, subsequent evaporation of the organic solvent yielded a sample of wool grease.

Example 5

OM-2T (120g) was shaken for a few minutes in a closed vessel with Corcat P150 (10g), a viscous liquid polymer of ethyleneimine. The polyamine was adsorbed onto the surface of the powder, whereby the bulk density decreased by about 50%. When this experiment was repeated using OM-2T (120g) and the very viscous Corcat 600 (4g), the polymer was again rapidly adsorbed and the bulk density decreased by about 30%. Both these modified powders cleaned a raw wool sample substantially better than the corresponding OM-2T powder, yielding a lower residual grease content and less residual powder.

Example 6

OM-2T was added to a solid sample of Polyethylene Glycol 6000 (6g), and the mixture was shaken for one minute. The bulk density of the powder decreased by about 40%. This powder was very effective in the degreasing of wool, skins, cashmere and mohair.

Example 7

A sample of sunflower oil (lOg) was shaken with several empty tins and a large handful of nails, screws, nuts and bolts. All the metal objects became coated with a fine layer of oil. This material was then shaken well with EMAG (lOOg) for about 10 min. The metal objects were then separated from the powder, shaken in a large sieve and blown with a stream of compressed air. All the objects were found to be free of oil and powder. A similar experiment was conducted with equal success using metal objects contaminated with lubricating grease. In this case the greasy objects plus EMAG powder were heated to 100° and agitated well, cooled, and the powder separated as before. Example δ

Example 7 was repeated using a mixture of small ceramic and small plastic objects in place of the nails, screws, etc. The EMAG powder was again effective in removing both sunflower oil and lubricating grease from these objects.

Example 9

A sample of mohair (20g, grease content 5%) was placed in a large stainless steel vessel with EMAG powder (20g) .and heated in an oven at 70° for 20 min. The contents were shaken briefly every five minutes. .After cooling, the mohair was hand carded. The residual grease and powder contents were both close to zero (<0.1%).

Example 10

A sample of DG1 wool (30g) was heated and intermittently shaken at 70 °C with OM-IT powder (80g) for 15 minutes. The wool was then cooled to room temperature, and carded by hand. A sample (l/6th) was removed and analysed for residual grease and powder. The remaining wool plus adhering powder was again cleaned as before, using one-half the amount of powder, namely 40g. The wool was again carded and a l/5th weight taken as a sample for analysis. The process was ^• repeated using successively smaller amounts of powder and smaller samples until six cleanings has been performed. The results are shown in Table 1 below.

Table 1

Cleaning Wool wt. Powder Carded Sample %G %D

No. wt. wool wt. wt.

0 18.7 1.7

1 30 80 33.8 5.6 13.8 23.3

2 28.2 40 27.0 5.4 8.2 23.4

3 21.6 20 19.1 4.8 5.7 18.5

4 14.3 10 12.9 4.3 3.6 13.9

5 8.6 5 8.0 4.0 2.7 9.5

6 4.0 2.5 3.9 3.9 2.1 6.1

These results show that OM-IT can substantially clean the wool, but that this particular powder is strongly retained by the (partly cleaned) wool, although as expected, the amount of powder retained decreases as the amount of residual grease decreases. Separate experiments showed that fully cleaned wool, with no residual grease, had very little if any natural affinity for the powders used in this invention.

Example 11

Example 10 was repeated using OM-1, i.e., finely powdered chalk with no surface layer of stearic acid. The cleaning action was much better than that observed using OM-IT. The residual grease was down to 1.4% after three cleanings, 0.5% after four and below 0.2% after five. The residual powder again decreased rapidly as the grease was removed. The detailed results are given in the Table 2 below.

Table 2

Cleaning Wool Powder Carded Sample %G %D

No. wt. wt. wool wt. wt.

0 18.7 1.7

1 30 80 28.3 4.7 5.1 14.7

2 23.3 40 20.5 4.1 2.8 7.7

3 16.4 20 14.9 3.7 1.4 3.6

4 11.2 10 10.9 3.6 0.5 2.4

5 6.3 5 6.7 3.4 0.2 0.6

Example 12

Example 10 was repeated using BDH chromatographic alumina as the cleaning powder. When this powder was being carded from the wool it separated readily and was easily collected. It did not disperse into the air as a fine cloud as was observed using very fine powders such as OM-IT and OM-1. After only two cleanings the residual grease was down to 1.4%.

Results are given in Table 3 below.

Table 3

Cleaning Wool Powder Carded Sample %G %D No. wt. wt. wool wt. wt.

0 18.7 1.7

1 30 80 24.8 4.1 4.4 3.6

2 20.7 40 19.3 3.9 1.4 0.9 Example 13

Example 12 was repeated but all operations were conducted at room temperature. After the first cleaning, the %G was 12.5 and the %D , 14.7; after the second cleaning the %G was 8.4 and the %D 14.6. It is clear from this result that heating of the wool to the softening or liquefaction point of the grease is a requirement for efficient cleaning. See also result using EMAG at 30 ^βC in Example 1.3 above.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Claims

CLAΓMS

1. A method for cleaning textile fibres or other materials which comprises contacting said textile fibres or other materials with a finely-divided particulate material, the particles of which have a capacity to adsorb oil, grease and other contaminants.

2. A method according to Claim 1, wherein the particulate material is an inorganic oxide, inorganic hydrous oxide, inorganic hydroxide, inorganic carbonate, inorganic silicate, inorganic phosphate, inorganic sulfate, carbon or sulphur or mixtures thereof.

3. A method according to Claim 2, wherein the inorganic oxide is anhydrous alumina (aluminium oxide), magnesia (magnesium oxide), titanium dioxide (titania or rutile), zirconium dioxide (zirconia) or silicon dioxide (silica).

4. A method according to Claim 2 or Claim 3, wherein the inorganic hydrous oxide is hydrated alumina.

5. A method according to any one of Claims 2 to 4, wherein the inorganic hydroxide is hydrated alumina (aluminium hydroxide).

6. A method according to any one of Claims 2 to 5, wherein the inorganic carbonate is calcium carbonate (chalk), magnesium carbonate (magnesite), calcium magnesium carbonate (dolomite) or strontium carbonate.

7. A method according to any one of Claims 2 to 6, wherein the inorganic silicate is calcium silicate (wollastonite), sodium aluminum silicate (sodalite), aluminium silicate (kaolinite), magnesium silicate (talc), zirconium silicate (zircon) or more complex natural or synthetic zeolites (aluminosilicates).

8. A method according to any one of Claims 2 to 7, wherein the inorganic phosphate is calcium phosphate, magnesium phosphate or zirconium phosphate.

9. A method according to any one of Claims 2 to 8, wherein the inorganic sulfate is calcium sulfate, strontium sulfate, barium sulfate or zinc sulfate.

10. A method according to any one of Claims 2 to 9, wherein the carbon is carbon black.

11. A method according to any one of Claims 2 to 10, wherein the sumir is powdered sulfur.

12. A method according to any one of the preceding claims, wherein the particulate material has a hydrophobic surface layer.

13. A method according to Claim 12, wherein the hydrophobic surface layer is an oleophilic surface layer.

14. A method according to Claim 12 or 13, wherein the surface layer comprises a long chain fatty acid.

15. A method according to Claim 14, wherein the long chain fatty acid is stearic acid, oleic acid or palmitic acid or mixtures thereof.

16. A method according to any one of Claims 12 to 15, wherein the particulate material is calcium carbonate coated with stearic acid.

17. A method according to any one of the preceding claims, wherein an additive is included to assist in softening of the oil and grease.

18. A method according to Claim 17, wherein the additive is an inorganic compound, organic polymer, organic detergent or organic solvent or mixtures thereof.

19. A method according to Claim 18, wherein the inorganic compound is sodium bicarbonate, sodium carbonate, slaked lime or magnesia.

20. A method according to Claim 18 or Claim 19, wherein the organic polymer is a cationic, anionic or non-ionic polymer.

21. A method according to Claim 20, wherein the cationic polymer is a polymer of ethyleneimine or an acrylic or similar polymer having amino or quaternary ammonium side chains.

22. A method according to Claim 21, wherein the acrylic or similar polymer is an Ultrion, Optimer or Alfloc cationic flocculent as marketed by the Nalco Chemical Company.

23. A method according to Claim 21, wherein the polymer of ethyleneimine is Corcat P18, Corcat P150 or Corcat P600.

24. A method according to any one of Claims 18 to 23, wherein the organic detergent is a cationic, anionic or non-ionic detergent.

25. A method according to Claim 24, wherein the cationic detergent is cetyltrimethylammonium chloride.

26. A method according to Claim 24, wherein the anionic detergent is sodium or ammonium dodecyl sulfate, dodecylbenzene sulfonate or a sodium salt of a fatty acid (soap) or of a sulfated oil.

27. A method according to Claim 24, wherein the non-ionic detergent is a sucrose ester of a long-chain fatty acid, an alkylaryl ether of polyethylene glycol) or a carbowax.

28. A method according to Claim 27, wherein the carbowax is Polyethyleneglycol 6000.

29. A method according to any one of the preceding claims wherein the particulate material is added to the textile fibres or other materials in a ratio of about 0.4:1 to about 3:1, respectively.

30. A method according to Claim 29, wherein the particulate material is added to the textile fibres or other materials in a ratio of about 0.5:1 to about 1:1, respectively.

31. A method according to any one of the preceding claims, wherein the textile fibres are selected from natural and synthetic fibres.

32. A method according to Claim 31, wherein the natural fibres are selected from animal fibres, insect-derived fibres, vegetable fibres and cellulose fibres.

33. A method according to Claim 32, wherein the animal fibres are selected from raw wool, goat hair, llama hair (alpaca), camel hair, horse hair and rabbit fur.

34. A method according to Claim 33, wherein the goat hair is selected from mohair and cashmere.

35. A method according to Claim 32, wherein the insect-derived fibre is silk.

36. A method according to Claim 32, wherein the vegetable fibre is selected from cotton, flax, rhamie, jute, manila, sisal and phormium.

37. A method according to any one of Claims 1 to 30, wherein the other material is selected from keratinous, metallic, ceramic, wooden, plastic and cellulosic materials.

38. A method according to Claim 37, wherein the keratinous material is selected from skins, hides and leather.

39. A method according to any one of the preceding claims, wherein the textile fibres or other materials are contacted at a temperature at or above the softening/liquefaction point of the grease contaminants.

40. A method according to any one of the preceding claims, wherein the used particulate material is recycled for further use, disposed of and/or converted into other useful products.

41. A method according to Claim 40, wherein the grease is removed from the used inorganic material and the inorganic material is recycled to be further used in the method.

42. A method according to Claim 40, wherein the used particulate material is disposed of in a land fill.

43. A method according to Claim 40, wherein the used particulate material is disposed of by anaerobic and/or aerobic digestion.

44. A method according to Claim 40, wherein the used particulate material is returned to the land as a fertilizer and/or soil conditioner.

45. A method according to Claim 40, wherein the used particulate material is incinerated to produce agricultural (slaked) lime.

46. A method according to Claim 40, wherein the used particulate material is incinerated to produce agricultural magnesia.

47. A method according to Claim 40, wherein the used particulate material is further used in vermiculture or as an additive to poultry or to fish food used in aquaculture.

48. A method for cleaning textile fibres or other materials which comprises the steps of: a) placing the textile fibres or other materials in an opening means, said opening means being arranged to open the textile fibres or other materials so that they can be readily coated with the particulate material defined in any one of Claims 1 to 16; b) heating the textile fibres or other materials; c) applying the particulate material to the opened textile fibres or other materials before or after step b); d) allowing the coated open textile fibres or other materials to cool; and e) separating the particulate material from the textile fibres or other materials.

49. A method according to Claim 48 wherein the particulate material is removed by subjecting the textile fibres or other materials to a tumbling or a carding process.

50. A method according to Claim 48 or Claim 49 wherein the textile fibres or other materials are subjected to multiple carding processes.

51. A method according to any one of Claims 48 to 50 wherein the textile fibres are animal fibres.

52. A method according to Claim 51, wherein the animal fibres are selected from raw wool, goat hair, llama hair (alpaca), camel hair, horse hair and rabbit fur.

53. A method according to Claim 51 or Claim 52 wherein the animal fibres are heated to a temperature at or above the softening/liquefaction point of the grease contaminants.

54. A method according to any one of Claims 51 to 53 wherein the wool is heated to a temperature of about 60 °C to about 80 °C.

55. A cleaning agent which comprises the finely-divided particulate material as defined in any one of Claims 1 to 16.

56. A method for controlling parasitic infestations in animals which comprises applying the finely-divided particulate material as defined in any one of Claims 1 to 16 to the afflicted, or affliction-prone areas of the animal in order to absorb and remove grease, dirt, suint, and dags and thereby reduce the likelihood of infestation.

57. A method according to Claim 56, wherein the particulate material is applied in a jet of air to the afflicted, or affliction prone areas of the animal.

58. Apparatus for cleaning textile fibres or other materials comprising a first container arranged to receive a quantity of textile fibres or other materials which are to be cleaned, said first container having opposed top and bottom walls formed with a plurality of apertures, said first container being housed within a second container so that an inorganic material introduced in a top portion of said second container will pass through the top wall of the first container, through the textile fibres or other materials contained in the first container and through the bottom wall of the first container.

59. Apparatus according to Claim 58 further comprising means to circulate air and suspended inorganic material within the first and second containers.

60. Apparatus according to Claim 58 or Claim 59 further comprising means to vibrate the first container within the second container.

61. Apparatus for cleaning textile fibres or other materials comprising an outer vessel and an inner vessel, said vessels being arranged for rotation about their longitudinal axis, said inner vessel being arranged to receive a quantity of textile fibres or other materials which are to be cleaned, said inner vessel being arranged to be substantially sealed so that a particulate material can be inserted in the inner vessel and the inner vessel rotated so as to distribute the particulate material to the textile fibres or other materials, said inner vessel being arranged to be removable from said outer vessel and said outer vessel having a circumferential wall formed from a material having a plurality of apertures therein.

62. Apparatus according to Claim 61 further comprising means to heat the textile fibres or other materials placed in the inner container.

63. Apparatus according to Claim 61 or Claim 62 wherein the inner and outer vessels are cylindrical in shape.

64. Apparatus according to any one of Claims 61 to 63 wherein the apparatus is contained in a housing.

65. Apparatus according to any one of Claims 61 to 64 further comprising a paddle means extending along the length of said inner vessel, said paddle means being ananged to tumble the textile fibres or other materials.

66. Apparatus for cleaning textile fibres or other materials comprising a first barrel arranged for rotation about its longitudinal axis, said first barrel being angled such that textile fibres or other materials inserted in the first barrel at an input end gravitate when the first barrel is rotated to an output end and wherein the first barrel is heated.

67. Apparatus according to Claim 66, wherein the first barrel is heated by direct application of heat to the external surface of the barrel.

68. Apparatus according to Claim 66 or Claim 67, wherein the first barrel is mounted on rollers.

69. Apparatus according to any one of Claims 66 to 68 further comprising a second barrel, said second barrel being arranged for rotation about its longitudinal axis and being angled such that textile or other materials inserted in the second barrel at an input end gravitate when the second barrel is rotated to an output end, and wherein the circumferential sides of the second barrel have a plurality of apertures formed therein.

70. Apparatus according to any one of Claims 66 to 69 wherein the first and/or the second barrel is formed in sections such that the length of each barrel can be varied by inserting or removing barrel sections.

71. Apparatus according to any one of Claims 66 to 70 further comprising paddle means extending along the length of said first barrel, said paddle means being arranged to tumble the textile fibres or other materials such that the textile fibres or other materials follow a substantially helical path from an input end to an output end of the first barrel.

72. Apparatus according to any one of Claims 69 to 71 further comprising paddle means extending along the length of said second barrel, said paddle means being arranged to tumble the textile fibres or other materials such that the textile fibres or other materials follow a substantially helical path from the input end to the output end of the second barcel.