EP0372038A1 - Animal hair treatment process - Google Patents

Abstract

A method of treating animal hair fibers comprises a first step of obtaining a plurality of discrete masses of animal hair fibers optionally in their alignment and their original shape, followed by a second step in which the plurality of masses are thoroughly cleaned separately from each other in a cleaning medium. The cleaning step comprises an initial treatment of the tip of the fibers followed by another treatment in which the fibers are completely immersed in the cleaning medium which is advantageously an organic solvent. Thorough cleaning can also be done in a batch process in which the masses of animal hair fibers are placed in separate permeable containers which are then soaked in the cleaning medium. In another embodiment, a continuous process can be adopted in which the masses of animal hair fibers are placed separately in a spaced relationship on a conveyor belt then passing through the cleaning medium. The plurality of animal hair masses are advantageously combined in an aggregate before carding.

Description

ANIMAL HAIR TREATMENT PROCESS This invention relates to a process for treatment of animal hair fibres and in particular wool by minimising fibre entanglement. In general, the most common methods of removing dirt, suint and grease from raw wool have involved the use of scouring systems which feed the contents of wool bales into aqueous scour vats. The separate processes of (i) packing of - wool in these bales_. (ii) the wool opening process which feeds wool into the delivery hopper, and (iii) the ensuing "slumping" of the wool as well as the movement and agitation of wool as it moves through the scouring vats all lead to a high level of fibre entanglement. This is a legacy of on- farm packing and handling and/or processing in aqueous media at the scour factory.

This entanglement must subsequently be removed so the wool can be converted to yarn. The removal of entanglement occurs mainly during the carding process where dry scoured wool is fed into a machine (or card) which aligns the fibres in parallel. This process causes substantial breakage of the fibres and there is a concomitant penalty inherent in removing the tangle. The breakage means that there is a low top: oil ratio of wool coming from the card and a simultaneous low average fibre length (approximately 30% reduction) for the aligned (parallel) fibres coming from the card when compared to the fibres fed into the card. These aligned and untangled fibres coming off the card constitute carded slivers which are then further processed to make a top. The low top:noil ratio and low average fibre length in the top reduce the value of the product of topmaking.

It therefore is an object of the invention to provide an animal hair treatment process which minimizes or alleviates fibre entanglement.

The process of the invention may include the following steps:

(i) providing a plurality of discrete masses of animal hair fibres optionally preserved in their original alignment and form; and (ii) scouring the plurality of masses separately from each other.

The process of the invention is applicable to any appropriate animal having hair fibres that may be scoured. For example the animal hair fibres may be selected from wool fibres, cashmere and other goat hair fibres , alpaca hair fibres, camel hair fibres, sable hair fibres, chinchilla hair fibres, fox hair fibres, astrakhan hair fibres, weasel hair fibres, racoon hair fibres, civet hair fibres and lamb hair fibres.

It will also be appreciated that the animal hair fibre masses may also be in the form of a mass of loose hairs, web, sliver or top. Preferably however the masses of hair fibres are constituted by fleeces of hair fibre which, when removed from the animal may be in the form of a coherent or cohesive mass.

Optionally the mass of hair fibres may be attached to a skin support but this is not essential.

It will therefore be appreciated from the foregoing that the discrete masses of animal hair fibres are not packed or pressed into a bale for transport which contributes to

- entanglement because the fibres in the bale then have to be separated using hooks land the like which damage the hair fibres.

Suitably when the _. animal hair fibres are removed from the animal by clipping or shearing they form coherent masses or fleeces which may be subsequently packed for transport in any appropriate fashion so long as the masses are separated from each other by appropriate means. For example the masses may be formed into layers or mats which are separated by layers of plastics sheet or the like. Any pattern of packing on a container may be adopted. For example each mat of fibres may be arranged in stacked relationship or alternatively they may be coiled about each other in spiral or concentric fashion. If desired a press may be used to press the separate mats of fibre into a *_* container or box. However, the press may be used in such a manner to avoid fibre entanglement. Alternatively vacuum packing may be adopted if required. Suitably before packing the animal hair fibres may be subjected to preliminary evaluation as is known in the art to assess strength of fibre, diameter, preliminary scour test evaluation and wool top evaluation. In another embodiment and especially where transportation is not required such as on-site or on-farm scouring the discrete masses of hair fibres may be taken straight to the scouring apparatus after being removed from the animal. In one embodiment separated masses of hair fibre suitably in the form of entire skirted fleeces may be taken to the scouring location by conveyor from the shearing shed or other site where the animal hair is removed from the animal. Any suitable scouring process may take place as is known in the art and this includes aqueous scouring and/or scouring using organic solvents. However, the scouring processes utilized may be gentle in nature so as to inhibit fibre entanglement and/or breakage. In a preferred form of the invention the separate masses of animal hair or fleeces may be scoured at room temperature and an aqueous scour medium may contain a surface active or other emulsifying agent for the removal of wool grease together with dirt release agents such as alkali metal silicates. Ammoniated detergents also may be utilized.

Preferably an aqueous scouring step is utilized followed by an organic solvent scouring step although either form of scouring step may be utilized in the process of the invention. If desired an organic solvent washing or cleaning step may be utilized prior to aqueous scouring. The preferred solvent is 1,1,1 trichloroethane for its relative cost and ease of recovery, although any other organic solvent may be utilized if required.

Where two phase mixtures of trichloroethane (TCE) are used, it is preferred to use from 0-250ml of water per litre of TCE with it being particularly preferred to limit the water content to 90ml/litre TCE for ease of stripping at drying time. More than 250ml/litre is not desirable since excessive decomposition of the solvent occurs, resulting in production of potentially destructive hydrochloric acid. The treatment with the solvent may be undertaken in either a batch or continuous process depending on the scale of operations. It is contemplated that, for on-station processing, batch processing may be more appropriate in terms of the capital cost of plant. For industrial scale applications, it is regarded that a continuous process would be chosen.

Where a batch process is used, the wool is advantageously contained in_. dip baskets that are dipped and agitated in a bath containing the solvent. Preferably, the wool is sequentially immersed in more than one bath to effect a thorough scour. In fact it is particularly preferred to place the wool in the dip baskets with the normally outer part of the fleece orientated downwards. Preferably, the basket is then slowly immersed in the solvent batch until submerged, and agitated to effect loosening of retained dirt and to ensure optimised dissolution of any residual wool grease. The basket is preferably rapidly removed from the solvent bath, the passage of solvent down through the fleece effective removal of dirt, grease and suint from the wool. The "tip down" configuration fo the wool reduces the number of solvent passes required. Where a continuous process is used, the fleece is preferably loaded onto a conveyor belt such as a perforated or metal mesh travelling belt which travels through one or more solvent baths. Again, it is particularly preferred to orient the fleece with the outer surface downwards. The solvent is then preferably slowly pumped into the bath until the fleece within the bath is immersed. The belt and fleece may be agitated from above or below to effect loosening of the fibres and the release of any residual dirt, grease and suint, after which the solvent is preferably rapidly released to effect the flushing effect of the solvent under gravity as described above.

In either the batch or continuous processes described above, agitation may be provided by mechanical or other means. It is particularly preferred to use ultrasonic vibration of the solvent medium to effect the agitation since an appropriate choice of frequency and energy input causes localized cavitation and vapour production within the medium. The bubbles of vapour then permeate the wool causing dislodgement of dirt and grease, and enhancing fibre separation without damage. Experience has shown that ultrasonic energy is appropriately supplied to the solvent baths by attaching transducers thereto which are capable of delivering ultrasonic energy at a frequency of 25KHz and at a power density of 40 watts per litre of solvent/wool medium. It is noted that this frequency of operation creates the optimum bubble formation in the present solvents.

Alternatively, agitation may be effected by entraining gas or vapour bubbles in the solvent by external means. For example, it is contemplated that gas jets may be employed to inject air, nitrogen or any other preferably inert gas into the solvent to effect agitation.

The organic solvent scouring step suitably uses chlorinated hydrocarbons such as trichloroethane, methylene chloride, or mixtures thereof and two phase solvent systems thereof. This results in superior drying performance of the wool. This overcomes problems of post processing of wool related to excessive water retention such as fibre shattering during the cryogenic deburring described hereinafter.

In common with other scouring processes, the wool after scouring by the process of the present invention is advantageously dried prior to deburring, carding and combing. It is surmised that, due to differential affinity of the wool for the solvents of the present invention over water, this results in the reduced drying effort recognized in wool scoured in accordance with the present invention. The wool is dried to the optimum level required for either deburring if required or to that required for efficient carding and combing.

In a particularly preferred scouring process adopted by the present invention the mass of animal hair fibre in tip down fashion may be passed through the scouring liquor in countercurrent manner wherein the fibres travel through the scouring liquor in an opposite direction thereof. The separate masses of animal hair fibre are retained in different baskets in a batch process or in separate sections of a perforated or mesh conveyor belt in a continuous process. It is preferred to pass the hair fibre in tip down fashion through the scouring liquor because approximately 50% of the impurities are located in the hair tips (i.e. approximately the top 2 cm of the animal hair) and such impurities are best removed by the flushing action of the solvent being drained from the mass of fibre.

If a plurality of scouring vats are utilized the separate fleeces or animal hair fibre masses may be squeezed dry after passage through each scouring vat. Suitably each scouring vat may be provided with a sump or drain for settlement of relatively heavy contaminants. It is sasier when using organic solvent scours to maintain the animal hair fibre masses separate from each other because the fibres do not "slump" or lose their coherent nature and thereby remain more separate. However in aqueous scours wool may "slump" and thus to overcome this problem the separate fleeces or masses of hair fibres may retain in a mesh bag or basket to inhibit "slumping". In this arrangement the mesh or perforated flexible bag may retain the coherence of individual fleeces. After passing through an aqueous scour the fleece or discrete fibre masses may be dried in any suitable fashion such as being spun dried or air dried. The same occurs after passage through an organic solvent scour. In drying after the aqueous scour the masses of hair fibres may be retained in their individual mesh bags. In this arrangement the spin dryer or centrifuge may be filled with solvent to reverse the fleece "slumping".

It is also within the ambit of the invention to process wool staples or fleece sections if such is considered appropriate.

Suitably the scouring apparatus utilized may include a conveyor of serpentine or sinusoidal shape comprising a plurality of peaks and troughs. The troughs may be located in associated scouring vats with wringers located downstream from each scouring vat.

In order to optimize cost benefits and to meet environmental constraints, it is desirable to recover solvent from all stages of the present process.' It is also desirable to minimize solvent turnover throughout the process. For example, in the multiple bath embodiments it is desirable for the final scour bath liquor after suitable make up to form the initial scour liquor. The make up solvent in part may be supplied by the condensate recovered from the preferred dryer gas effluent. The rest, and replacement solvent for the _ downstream solvent bath or baths may be provided by recovery of solvent from the solvent jet scour if used and the contaminated initial bath liquor.

It has been found that it is advantageous to filter the contaminated liquors to remove particulates through, for example, a pressure filter. After filtration, the solvent may be distilled to recover solvent or solvent azeotrope (as the case may be) leaving a residue of crude lanolin. However, it is particularly preferred to further pass the filtrate from the pressure filter through a bed of a cationic exchange substance in order to remove oxidized lanolin (wool grease) from the filtrate prior to low temperature vacuum distillation. This results in a purified lanolin by-product of higher value. The preferred cationic exchange substance is selected from the group consisting of bentonite and montmorillionite clays, with bentonite being particularly preferred. The suitability of the present solvent systems for solvent recovery by the above method, yielding as it does the surprisingly pure lanolin product, further evidences the suitability of the present solvents for integrated scour processes which are substantially non-polluting and economical. Wool fleeces are to varying degrees contaminated by burrs such as noogoora and the like which are not removed by scouring. It is preferable to remove burrs prior to carding and combing. In the past, deburring has been undertaken by carbonizing the burrs using concentrated sulphuric acid, followed by rinsing, drying and crushing the wool to in turn crush the carbonized burr. This process is understandably harsh and results in dingy wool which is tangled and has lost yet more character of the original wool.

As an alternative less harsh process it is now proposed to utilize cryogenic deburring as a further embodiment of the present invention, wherein the scoured wool is immersed in liquid nitrogen for sufficient time to freeze the burrs to make them brittle. The wool is then allowed to warm at ambient temperatures until the fibres are thawed but the burrs are still frozen. The wool is then crushed in an impact crusher to fragment the burr, which then winnows out of the wool during carding and combing.

A possible disadvantage of cryogenic deburring when used after conventional scouring processes is that, due to differential thawing of the wool, some fibres may remain frozen and are subsequently shattered during the crushing step. It is theorized that the source of the thawing problems of the wool is the water content of the aqueous scoured wool. The present process, by the use of the present solvents, provides wool of a lower and more homogeneous water content. This renders the scoured wool more suitable for cryogenic deburring since it is the water, having a higher specific heat than wool, is presumed to be the cause of prolonged thawing times of wool.

Wool tips scoured in accordance with the present invention are preferably subsequently immersed in liquid nitrogen for approximately 25 seconds. The wool is then drained of liquid nitrogen and preferably allowed to dry at ambient temperature for 50 to 70 seconds. The wool containing the frozen burrs is then preferably crushed in an impact crusher to effect disintegration of the burrs.

A major advantage of the present inventive process lies in the retention of the character of the source raw wool throughout the process. This enables the scoured wool to be assessed for its spinning and other characteristics after scouring, whereas wool scoured by prior art processes has lost character and cannot be so assessed. Overseas buyers have tended to buy raw wool to ensure that the spinning performance of the wool could be accurately assessed. When wool scoured by the present process has attained market acceptability it will be possible to establish wool scouring plant running a process in accordance with the present invention at the shearing shed, thus reducing shipping costs. Also scoured wool is easier for mechanical packing apparatus to handle, eliminating the standard shipping bale and enabling the use of, for example, high density vacuum packing. obviously, the scoured wool is a higher value commodity than raw wool.

During experimentation using the process of the invention it was noted that staple configuration was important and that loading of a perforated conveyor or basket with the wool in the tip down position during tip scouring and TCE scouring involving total immersion of the fibres provided advantages of:-

(a) minimizing entanglement;

(b) facilitated the removal of contaminants by a positive flushing action of the solvent;

(c) allowed for differential scouring of tip and separate discard of this waste which included dirt and low value lanoline;

(d) allows for slow immersion and rapid withdrawal cycles of solvent dynamics to keep the contaminants continually moving in a distal (i.e. towards tip) direction. The use of sedimentation and/or filtration minimized the extent of re-contamination which is a common problem in traditional scouring; (e) the technique also facilitates the use of cryogenic deburring because solvent scouring and comprehensive drying permits a disparate rate of thawing of the burr against wool fibres after freezing both in liquid nitrogen.^' Capitalizing on the tip down configuration provides the advantage as only the wool tips have to be immersed in liquid nitrogen and thus this allows only the tip and burr to freeze. After waiting for the tip wool to thaw the frozen burr can be crushed for subsequent conversion to powder; (f) whole fleeces which are scoured yet remain untangled using the process of the present invention create a good opportunity to feed the untangled wool into a card which may be of modified design since only a gentle action is required unlike conventional card machinery.

It must also be realized that in conventional aqueous scouring processes it is not possible to get the staples to stand upright throughout the scouring process.

The fibres "slump" and this means that the advantages (a) , (b) , (c) , (d) and (e) described above are not obtained.

However, in relation to the present inventio -which concerns initial aqueous scouring followed by solvent scouring the fibres do not "slump". This effect is enhanced if the tips only are immersed and the physical parameters of aqueous scouring (temperature and pH) which concern the aqueous liquor are carefully controlled. One of the major disadvantages of solvent scouring is the requirement for clean solvent. This places heavy demands on the distillation of dirty solvent, demands which have been traditionally met by very large distillation equipment. In an attempt to reduce the magnitude of this problem we have studies a number of filtration processes. The one reported herein uses industrial chromatography to "clean up" dirty solvent and reduce our dependence on distillation. A montmorillenite clay with high cation exchange potential (i.e. bentonite) successfully removes dirt and high molecular weight (oxidised) lipids from contaminated solvent. The oxidised lipid is retarded in the proximal fraction of the filter bed and can readily be scraped off to allow fresh bentonite to be used in its stead. This oxidised lipid (and dirt) mixture has a potential use as an organic fertilizer.

This chromatography system allows the low molecular weight lipid (i.e. the high grade lanolin) to remain in the solvent phase and thereby permit its subsequent recovery by distillation. The costs of distilling this "σleaned-up" filtrate is markedly less than a process involving distillation without prior use of bentonite. These lower costs reflect a reduction in the rate at which solvent has to be distilled and also a reduction in level of solvent contaminants which in turn means that less heat energy is required to vaporise the solvent. EXPERIMENTAL

Wool is placed tip down on a basket or conveyor and the tip slowly immersed to a depth of approximately 2 cm of scour liquor (either aqueous or solvent) .

The wool is left to thoroughly wet the tip (2 min aqueous or 30 sees solvent) before withdrawal. The dirty scour liquor produced by the tip saturation is kept separate

- since it is contaminated with dirt, pesticides and oxidised lipid as well as some non-oxidised lipid.

The process is then continued by slow immersion of the whole staple in a solvent (TCE preferred) scour liquor followed by a rapid removal of the staples from the solvent. This is effected by movement of the basket of wool or by pumping and withdrawal of solvent in the conveyor system. The slow immersion and quick withdrawal process is repeated for a period of 6-8 minutes per sample of wool being cleaned. The process is designed to move contaminants in a distal direction (i.e. towards the tip) and thereby continually draw these contaminants in one direction along the staple profile. A cascade effect is used to ensure that wool is being exposed to solvent which itself contains progressively less contaminants as the cleaning process continues. Solvent cleaning is covered in a separate component of this submission. Quantitative expression of solvent contamination varies from <3g/l of lipid at the outlet (cleaned wool) end of the cascade to a value of up to lOOg/l of lipid at the inlet (dirty wool) end of the cascade. These values are for lipid contamination but would include some dirt particles which do not quickly settle. The settled dirt particles (sediment) are normally removed by using a gravity sink which enables ready removal of the heaviest contaminants.

The chromatography bed for bentonite- trichloroethane is described as follows:- - wt of bentonite 1kg void volume 1.31 position of dirt/lipid retardation on column occurs in proximal or top 8% of chromatography bed.

These figures relate to one single elution of dirty solvent containing 35g/l total contaminants. The data presented in Table 1 indicates the extend to which dirty solvent can be "cleaned up" using this industrial chromatography system. The materials and methods were as described above. Sources of dirty solvent were obtained by cleaning 30, 60, 90, 120 and 150 g samples of greasy wool in separate 1 litre volumes of clear TCE. The wool had a clean scoured yield of 66% and the figures in column 1 reflect the outcome of cleaning the wool, allowing heavy sediment to settle (two minutes) and decanting supernatants as text aliquots. TABLE I

Level of Solvent combination ^Solvenc Power

Column 1 reflects total contamination; column 2 contamination after sediment removal; column 3 the contamination after separation of heavy sediment and elution through bentonite. These figures represent efficiency of dirt, grease, suit removal following 1 x 5 minutes immersion of greasy wool samples in each solvent solution.

It is clear from this data that high levels of contamination such as 50 g/1 can be successfully cleaned with one passage through the industrial chromatography system. The eluate so produced has high solvency power for wool cleaning and a low level of contamination.

By the performance also of the present invention improved processability of animal hair fibres after scouring may be measured by suitable parameters such as the top/noil ratio and average fibre length in the top. These two parameters are largely dependent on the degree of fibre entanglement and tensile strength of the wool. By experiments now undertaken improved top/noil ratio and average fibre lengths have been obtained in regard to wool processed by the present invention.

It is also pointed out that in addition to the chlorinated hydrocarbons used in the present invention that other halogenated hydrocarbons may be used such as brominated or iodated derivatives. Also halogenated ethers may be utilized.

Also in regard to agitation techniques that could be employed in both the aqueous scouring step or the organic

- solvent scouring step as stated previously directional air/water jets or air/solvent jets may be used for example in a spa bath arrangement. These directional jets may be used in addition to or to replace conventional agitation steps used in aqueous or organic solvent scouring processes whereby the wool may be passed through vats of aqueous scouring liquor or vats of organic solvent.

The abovementioned directional jets may also be used in the treatment step with the solvent to improve fibre strength if desired.

In another possible embodiment the wool scouring process in a batch procedure could be carried out in large automatic washing machines using agitation, soak, wash, rinse and spin dry cycles with water (plus detergents) for the first cycle to remove dirt etc., and then solvent for the soak, wash, rinse and spin dry cycles or any combination thereof.

The specially designed washing machine would have automatic valves to direct the aqueous scour liquors and residues to a standard scour liquor treatment process and then later to direct the solvent liquors to the solvent and lanolin recovery processing steps. The wool fleece should be in tip outward configuration and should be confined within an open mesh container to avoid fibre entanglement. This container could be flexible or fixed with flexible being preferred.

Suitably before passing each separate fleece through to the scouring bath the tips are pre treated so as to remove impurities such as dirt, grease, sweat and the like and loosen the tips which may be annealed together by the impurities.

In one form of pre treatment the tips may be passed through an aqueous system. In this arrangement suitably the tips are in a tip down orientation and passed through a shallow bath or vat in which only the tips are immersed. The bath may also contain an appropriate detergent such as those described previously. In this arrangement the water may pass through the perforations in a perforated belt or through a mesh basket to contact the tips. After application of this treatment the impurities may fall into the vat and these may include oxidized lanolin, greases, sweat, salts and the like. A press may also be used to ensure contact of the tips with the water in the form of liquid or spray. In the aqueous pre treatment the water may be applied to the tips in the form of a spray or mist and may also be heated to emit a tip cleaning vapour admixed with detergent.

In this arrangement it will also be appreciated that the wool fleece may be stationary and the aqueous system or vat move through the stationary tips which in some cases may also adopt a tip up orientation.

In another system of tip pre treatment that may be used the tips may be subjected to an atmosphere of suitable - organic solvent such as those described previously or which may include petroleum or oil based solvents such as naphtha. In this arrangement the tips may be sprayed with a mist or spray of organic solvent. . Suitably one litre of organic solvent may be used per fleece which may be 4-5 kg in weight. The tips may be in a tip up or tip down orientation with the tip up orientation being preferred. Suitably the fleece may pass through the pre treatment zone in 30 - 60 seconds and then be subjected to a drying or retention period of 3-4 minutes before the entire fleece is subjected to a scouring action. Suitably in this arrangement the tips may pass through a vat containing the mist of organic solvent equipped with a reservoir of organic liquid in the base thereof. Again the impurities from the tips such as those described above may fall to the bottom of the vat. Again while it is possible for the vat to move through the stationary tips it is very much preferred for the tips on a perforated conveyor belt or mesh basket to move through a stationary vat.

In the above process water is a more effective cleaning agent than organic solvents and thus may be the preferred agent utilized in regard to tip pre treatment. However, in regard to the process of this invention organic solvents are preferred scouring agents because they do not cause "slumping" of the animal hair fibres as is the case with water. Thus aqueous scouring agents are suitable avoided especially with the objective of minimizing fibre entanglement.

Reference may now be made to a preferred embodiment of the present invention wherein:

FIG 1 is a flow sheet of the process of the invention; FIG 2 is a schematic drawing of the process of the invention utilizing a batch procedure;

FIGS 3a, 3b and 3c are schematic drawings of the process of the invention utilizing a continuous procedure;

FIG 4 is a schematic drawing illustrating the process of the invention utilizing an alternative continuous procedure to that shown in FIGS 3a, 3b and 3c; and

FIG 5 illustrates a schematic drawing of a recycling procedure for cleaning of solvent used in the process of the invention. In the drawings there is shown a flow sheet in FIG

1 which is self explanatory. The wool fleeces which are rolled up separately from each other are unrolled before being placed tip down on a mesh conveyor and subjected to a tip pre treatment procedure before being scoured in an organic solvent. This causes separate fleeces to be broken up into clumps of wool before drying of the scoured wool. Used solvent is then passed to a centrifuge to recover spent solvent which is subsequently filtered to remove dirt and oxidized lanolins. The spent solvent is then distilled and - the subsequently obtained recovered solvent is passed to the tip pre treatment medium. Wool wax may be recovered from the distillation procedure for subsequent transportation to the refinery for utilization as lanolin products.

In FIG 2 there is shown a stack of separate fleeces 10 which are placed tip down in baskets 11 carried by conveyor 12 having head rollers 13, tail rollers 14, and intermediate idler rollers 15 approaching tip pre treatment zone 16 in scouring tank 9, which is defined by downward ramp 17, level portion 18 and upward ramp 19. The tips of the fleece may be subjected to gentle cleansing action as described previously. The remainder of each fleece does not contact the scouring medium 20 which may also be applied to the fleeces by agitation sprays 21 in the tip pre treatment zone 16. After passing through the tip pre treatment zone the fleeces in baskets 11 pass through level zone 22 wherein they are removed from the scouring medium before being passed into the scouring zone 23. There is also shown downward ramp 24 which passes baskets 11 into zone 23 wherein the fleeces are fully immersed in scouring medium 20 which is retained in bath 9. There are also provided drains 26 and 27 wherein spent scouring medium may be passed for filtration and further purification. After passing through scouring zone 23 the baskets 11 are conveyed up upward ramp 28 to unloading zone 29 wherein the fleeces 10 are unloaded into centrifuge 30 for drying purposes. The fleeces may then be passed to a - secondary conveyor 31 wherein the fleeces 10 are passed separately through a dryer 32 before being passed into a cryogenic bath 33 before being subjected to crushing rolls 34. The fleeces 10 may then be loaded onto table 35 in stacked relationship for subsequent treating operations which include carding for example. Conveyor 31 is controlled by head roller 31A, tail roller 3IB and intermediate idler rollers 31C as shown.

In FIGS 3a, 3b and 3c there is shown a plurality of fleeces 10 in stacked relationship loading and layout table 36 adjoining scouring tank 9. The fleeces 10 are loaded onto perforated or mesh conveyor 37 separately and subsequently passed into tip pre treatment zone 38. This zone includes skimmer box 39, pump 40 and agitation sprays 41, as well as drains 26 and 27 wherein spent scouring fluid 43 may be passed for purification treatment which includes filtering. The skimmer box 39 and pump 40 are useful in clearing top surface debris from scouring fluid 43. There is also included idler roller 44.

The fleeces 10 may then be passed into scouring zone 45 wherein the fleeces are fully immersed in scouring fluid 43 which also includes skimmer box 39 and pump 40. Agitation sprays 41 are also utilized in scouring zone 45 which also includes idler roller 44.

The fleeces 10 may then be subsequently passed through a rinsing zone 46 which is defined by upward ramp 47 - of conveyor 37. There is also included separator 48 which breaks fleeces 10 into clumps, head pulley or roller 49 and idler roller 44. The clumps may then be passed through chute 50 into centrifuge 51 powered by motor and gearbox assembly 52. In centrifuge 51 the fleeces 10 are collected into an aggregate. Subsequently wool and remaining solvent is passed from centrifuge 51 up conveyor 53 to cyclone separator 54 wherein the remaining solvent is discarded up chimney 55. The remaining solvent passed up chimney 55 may constitute about 3% of the initial solvent that is utilized. Subsequently cleaned wool may be inspected for quality at inspection point 56 before being passed up pneumatic conveyor 57 into storage bin 58 containing baffle 59 and dust collector 60. The final cleaned and scoured wool may be passed through discharge location 61 for subsequent transportation and storage. There is also provided electric motor 62, suction fan 63 for pneumatic conveyor 57 and air exhaust 64.

In FIG 4 there is illustrated an alternative continuous process which does not use a tip pre treatment procedure. The fleeces 10 from loading table 65 are passed into conveyor 66 above the level of scouring fluid 43 before being passed into scouring zone 45. Subsequently a continuous process as described above in FIGS 3b and 3c is utilized.

The recycling of solvent is shown in FIG 5 wherein the scouring tank 9 is supplied with clean detergent or solvent through line 67. The tank is provided with drains 26 and 27 wherein spent or dirty solvent is passed through line 68 to pressure filter 69 before reaching distillation vessel 70." The pressure filter 69 may be precoated with diato ite, bentonite, acid activated clay, carbon or montmorrilonite. There is also provided pump 71 as well as condenser 72 for passage of clean solvent through line 67. Stabilizers may also be added as shown if required. There is also provided line 73 for passage of wool wax 74 or other materials collected from the distillation vessel for further refining. Cooling water may be passed through condenser 72 through lines 75 and 76.

Claims

CLAIMS 1. A process for treatment of animal hair fibres including the steps of:

(i) providing a plurality of discrete masses of animal hair fibres optionally in their original alignment and form; and (ii) scouring the plurality of masses separately from each other in a scouring medium.

2. A process as claimed in claim 1 wherein after animal hair fibres are removed from an animal they are packed for transport in masses or fleeces which are separated from each other.

3. A process as claimed in claim 1 wherein after animal hair fibres are removed from an animal they are conveyed directly to a scouring location in separate masses or fleeces.

4. A process as claimed in claim 1 wherein the plurality of masses of animal hair fibres are scoured separately from each other using an initial fibre tip scouring step followed by a scouring step in which the fibres are fully immersed in the scouring medium.

5. A process as claimed in claim 4 wherein the fibre tip scouring step is carried out using an aqueous step scouring medium.

6. A process as claimed in claim 4 wherein the fibre tip scouring step is carried out in an organic solvent.

7. A process as claimed in claim 4 wherein the full immersion scouring step is carried out using an organic solvent as the scouring medium.

8. A process as claimed in claim 1 wherein the plurality of masses of animal hair fibres are placed in separate permeable containers such as mesh bags or baskets in a batch procedure and passed through the scouring medium.

9. A process as claimed in claim 8 wherein the baskets are passed through the scouring medium in counter current

- manner wherein the baskets travel in an opposite direction to the direction of travel of the scouring medium.

10. A process as claimed in claim 1 wherein the plurality of masses of animal hair fibres are passed through a scouring medium in separate sections of a perforated or mesh conveyor belt in a continuous procedure.

11. A process as claimed in claim 10 wherein the mesh or perforated conveyor belt is passed through the scouring medium in counter-current manner wherein the conveyor belt travels in an opposite direction to the direction of travel of the scouring medium.

12. A process as claimed in claim 4 wherein the plurality of masses of animal hair fibres are scoured in tip down fashion.

13. A process as claimed in claim 1 wherein the plurality of masses of animal hair fibres are dried separately in individual mesh bags or other permeable containers.

14. A process as claimed in claim 4 wherein the conveyor is of serpentine or sinusoidal shape comprising a plurality of peaks and troughs.

15. A process as claimed in claim 1 wherein the plurality of masses of hair fibres after scouring are subjected to a cryogenic deburring procedure wherein each mass has at least the tips thereof are frozen in liquid nitrogen prior to crushing the frozen burrs.

16. A process as claimed in claim 1 wherein after the scouring step spent scouring medium is passed through a

- filtering step so as. to provide regenerated scouring medium which is then recycled for further use.

17. A process as claimed in claim 1 wherein during the scouring step the plurality of masses of animal hair fibres are subjected to agitation.

18. A process as claimed in claim 17 wherein the agitation is ultrasonic agitation.

19. A process as claimed in claim 17 wherein the agitation comprises an application of air/water jets or air/solvent jets to the masses of animal hair fibres.

20. A process as claimed in claim 17 wherein the agitation comprises immersing each mass of animal hair fibre in an automatic washing machine in a permeable container.

21. A process for treatment of animal fibres including the steps of:

(i) providing a plurality of discrete masses of animal hair fibres in their original alignment and form;

(ii) scouring the plurality of masses of animal hair separately from each other in a scouring medium wherein the masses are contained in permeable containers before immersion in the scouring medium in a batch scouring procedure; and

(iii) combining the plurality of masses of animal hair in an aggregate prior to carding.

22. A process for treatment of a inal fibres including the steps of:

(i) provising a plurality of discrete masses of animal hair fibres in their original alignment and form;

(ii) scouring the plurality of masses of animal hair separately from each other in a scouring medium wherein the masses are contained in separate sections of a conveyor which is passed through the scouring medium in a continuous procedure; and

(iii) combining the plurality of masses of animal hair in an aggregate prior to carding.

23. A process for deburring animal fleeces wherein the fleeces are subjected to a cryogenic bedurring procedure wherein at least the tips thereof are frozen in liquid nitrogen prior to crushing the frozen burrs.