AU615559B2 - Animal hair solvent treatment process - Google Patents

Description

ib ,a OPI DATE 05/01/90 APPLN. ID 38301 89 PCT AOJP DATE 01/02/90 PCT NUMBER PCT/AU89/00250 INTERNATIONAL APPLICATION P ISHD D H T COOPERATION TREATY (PCT) (51) International Patent Classification 4 International Publication Number: WO 89/12121 D01C 3/00 Al (43) International Publication Date: 14 December 1989 (14.12.89) (21) International Apolication Number: (22) International Filing Date: PCT/AU89/00250 8 June 1989 (08.06.89) (81) Designated States: AT (European patent), AU, BE (European patent), BR, CH (European patent), DE (European patent), FR (European patent), GB (European patent), IT (European patent), JP, KR, LU (European patent), NL (European patent), SE (European patent), SU, US.

Published With international search report.

With amended claims.

Priority data: PI 8703 PJ 2856 9 June 1988 (09.06.88) 22 February 1989 (22.02.89) (71) Applicant (for all designated States except US): WOOL CLEANING TECHNOLOGIES LIMITED [AU/AU]; 3rd Floor, 79 Eagle Street, Brisbane, QLD 4000 (AU).

(72) Inventor; and Inventor/Applicant (for US only) HOPKINS, Peter, Stewart [AU/AU]; 29th Level, 123 Eagle Street, Brisbane, QLD 4000 (AU).

(74) Agent: G.R. CULLEN COMPANY; 8th Floor, 79 Eagle Street, Brisbane, QLD 4000 (AU).

(54) Title: ANIMAL HAIR SOLVENT TREATMENT PROCESS (57) Abstract A process for treating wool with an organic solvent for an optimum contact time to improve the fibre strength whereafter said contact time said fibre strength decreases with further effluxion of time. Suitably the contact time has an upper limit of minutes and a lower limit of 2-3 minutes dependent upon the sort of agitation employed in the treatment process. Preferably the solvent is selected from halogenated hydrocarbons or halogenated ethers and the treatment process also combines a separate process for minimising fibre entanglement wherein a plurality of discrete masses of animal wool fibres optionally in their original alignment and form are scoured separately from each other in a scouring medium for the minimum contact time prior to being combined as an aggregate before carding.

WO 89/12121 Pcr/AU89/00250 1 ANIMAL FAIR SOLVENT TREATMENT PROCESS This invention relates to a process for treating wool and in particular relates to a new solvent treatment process.

In general, the most common methods of removing dirt, suint and grease from raw wool have been aqueous processes relying on the use of surface active agents in hot or cold neutral or alkaline water, combined with raking type agitation of the wool. It has been recognized that these traditional methods of aqueous scouring result in fibre entanglement resulting from "slumping" of the wool. This fibre entanglement results in fibre breakage during subsequent carding and combing processing steps. Typically the average fibre length in processed wool tops is 70% to 1b of that of raw or greasy wool. This in turn results in reduced quantity and quality of wool reporting as valuable wool top products.

Recent advances in aqueous scouring systems have mainly been directed to reducing the consumption of scour chemicals such as in Soviet Patent No. 1183575.

Other advances, such as that disclosed in U.S.

Patent 3708262 to Kanegafuchi Spinning Co. Ltd., Japan, disclose the use of preliminary scouring of the raw fleece in order to reduce the trauma to the fibres. In the above specification scour liquid is drawn down gently through the fleece by suction to remove at least part of the grease and dirt from the wool.

Soviet Patent No. 996532 discloses the use of ultrasonic agitation of the liquid scour medium in an attempt WO 89/12121 PCT/AU89/00250 2 to reduce the physical damage to the wool fibres. This disclosure recommends ultrasonic oscillation of the aqueous medium at between 100KHz and 250KHz, stating that at lower frequencies complete removal of contaminants is not obtained whilst at frequencies higher than 250KHz, the wool fibres roll up, which has a negative affect on spinning.

Although the above represent significant improvements over traditional hot aqueous scouring processes, all of the above processes realize some loss of fibre length in the wool tops over that of the raw wool. This loss of fibre length is generally believed to be caused by the use of aqueous systems with resultant "slumping" of the wool fibres.

As an alternative to aqueous scouring, and in an attempt to overcome the inherent problems associated with it, there have been proposed several solvent and solvent related processes for scouring wool. For example, both British 'atent No. 1233901 and U.S. Patent No. 3,619,116 propose the use of trichloroethylene or perchlorethylene as the scour liquid, with the usual vigorous agitation. The used solvent is then extracted with water/alcohol and distilled to recover solvent and purified lanolin.

Other advances using solvent scouring technology include that disclosed in Australian Patent Application No.

40379/85 to Extraction de Smet which involves a washing using an aqueous/alcoholic solution. This is then followed by rinsing the wool in a hydrocarbon solvent.

U.S. Patent No. 3,600,124 discloses a process using a hydrophilic solvent or mixture of solvents (such as WO 89/12121 PCT/AU89/00250 3 acetone) as a post-scour to a conventional aqueous scour.

Similarly, U.S. Patent No. 4,343,619 proposes the use of a solvent post scour to reduce the residual grease content of the wool.

Japanese Patent Application No. 138032/76 conversely discloses the use of an initial solvent scour using high flash point petroleum solvent prior to an aqueous scour. The stated object of this process is to reduce the waste water quantity whilst increasing wool grease recovery, and as such it is thought that the resultant scoured wool will have the same properties as conventionally scoured wools.

South African Patent Application No. 5106/73 proposes the use of an emulsion scour comprising an aqueous medium, a non-ionic surfactant and a non volatile solvent selected from animal and vegetable oils. Again, this method has the inherent properties of aqueous scours.

Reference is also made to a wool scouring process described in U.S. Patent 4,343,619 and Australian Patent 533,117. This process included the following steps:treating greasy wool with organic solvents including 1,1,1, trichloroethane and methylene chloride; and (ii) subjecting the wool treated after step to ,j an aqueous washing or scouring procedure as described above.

The above process only used the organic solvent as a preliminary scour followed by the normal and conventional aqueous scour. Thus it is considered that the disadvantages as described above with aqueous scours were applicable to P~i ,2 WO 89/12121 PCT/AU89/00250 4 this process.

However, it also must be borne i: mind that the above process only disclosed use of 1,1,1, trichloroethane as a preliminary cleaning step prior to use of an aqueous cleaning or scouring step. The above process could not be utilized in many applications because of the problems and cost in conversion of existing plant or equipment using an aqueous scouring step to incorporate preliminary treatment by immersion of the greasy wool in the organic solvent.

Further, this procedure still involves the use of a final aqueous cleaning or scouring step. Such a step will still result in "slumping" of the wool fibres leading to subsequent entanglement and resultant fibre breakage during combing and/or carding.

Also the disclosure of U.S. Patent No. 4,343,619 and Australian Patent 533,117 states that it is essential that in the abovementioned initial step of cleaning the greasy wool with the organic solvent it is also essential that the organic solvent include 0.1 to 10% of a raw animal hair grease which has been extracted from the same type of greasy animal hair undergoing processing. The inclusion of the raw animal hair grease, is not required in regard to the present invention and thus the process and apparatus of the present invention is simplified.

Also U.S. Patent No. 4,343,619 and Australian Patent No. 533,117 refer to the production of a scoured :N animal hair material retaining 1 to 3% by weight of residual soapy substance and 0.3 to 5.0% by weight of-residual fatty WO 89/12121 PCT/AU89/00250 The process of the invention includes the steps of: contacting said animal fibres for an optimum contact time of 2-15 minutes in an organic solvent to increase the fibre strength thereof; and (ii) removing said organic solvent to provide animal fibres suitable for carding and/or topmaking.

characterised in that steps and (ii) are t1-OLu_ OLA6:AtnrN\ ci i~c-eir.

carried outi 1p h In regard to the present invention it has now been discovered that there is an optimum contact time between the *0

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S S a 00 e *6 WO 89/12121 PCT/AU89/00250 substance. Again the deliberate inclusion of these substances is not required in the present invention. Also U.S. Patent 4,343,619 and Australian Patent 533,117 refer to the inclusion of an additional step of moving either one or both of the aniral hair material and the scouring liquid in relation to each other at a relative speed of 3 to 60 m/min.

This additional step is not essential in the present invention particularly in batch processing. However for continuous processing on belt conveyors this counter-current flow of scouring fluid and wool fleece is preferred but the relative flow rates are not critical to scouring performance.

It is an object of this invention to provide a process of scouring wool which alleviates at least some of the problems associated with the prior art and also significantly improves fibre strength. This in turn may lead to an increase in fibre length and value of the subsequent wool top products for yarn and fabric manufacture.

The increase in fibre strength may also increase wool top to noil (short fibre) ratios by lower fibre breakages..

it is a furthe of the n4-_ apparatus suitable for use in the above process.

The process of the invention inclu e the steps of treating wool with an organic solvent ionally comprising a halogenated hydrocarbon, h genated ether or mixtures thereof for an optimu contact time *9 improve the fibre strength.

n regard to the present invention it has now been n -'111A .I7, Aall--~---i

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ii~8~~(~f~fd~i~i~~n~rUtii~Wll~i~~W~"~~P~I WO 89/12121 PC/AU89/00250 organic solvent which preferably is a halogenated hydrocarbon inclusive of trichloroethane and mjthylene chloridek In other words, there is an upper limit relative to the contact time which is dependant on various factors such as method of agitation, the specific solvent and the specific animal hair being processed. Also animal hair quality may be a factor such as fibre diameter, original fibre strength and fibre type.

It has therefore been discovered that the abovementioned upper limit relative to contact time is suitably of the order of 15 minutes and more suitably minutes for normal agitation methods and in some cases less than 5 minutes for extreme agitation methods ultrasonic vibration).

It has been further found in the case of extreme agitation methods (ultra-sonic vibration) that after the aforesaid upper limit has been reached that the fibre strength decreases with the duration of time to eventually reach its original value. As the fibre strength decreases beyond its upper limit the fibre becomes increasingly brittle. This fibre brittleness has been the observed disadvantage of solvent scoured wool in the past. This invention not only increases fibre strength but stops the solvent reaction process at a point where no real damage is done to other fibre properties.

In the case of wool subjected to normal agitation methods (including submersion -I.nd jetting of the submersed wool with low pressure high solvent jets) the fibre strength i i:i t~ j

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1 WO 89/12121 PCT/AU89/00250 7 increases progressively during the first 10 minutes. The actual fibre strength values after 10-15 minutes are variable and unpredictable in that they can continue to increase or decrease or can even remain constant. Preferably fresh or unused organic solvent is utilized in this invention which may flow counter-current to the wool in a bath. The contact time between the immersed wool and the organic solvent is preferably 6 to 10 minutes and the residual fatty substance content of the spnnt solvent from the scouring operation is suitably less than 3% (preferably 1.5% to in order to obtain the desired scouring conditions.

If desired a rinsing step may be employed where fresh organic solvent is applied to the scoured or cleaned wool to remove detergent residues added to the solvent in the bath.

The wool if desired can be initially treated in an initial &queous or organic solvent based scouring step.

However, more preferably the aforementioned minimum contact time with the organic solvent can be used as a scouring step particularly when treating raw wool or greasy wool.

The initial aqueous scouring step may comprise any suitable conventional aqueous scouring step as is known in the art and which have been broadly summarized above.

Initial aqueous scouring may also include tip scouring to minimise wool slumping. Initial scouring using an organic S-' solvent is preferred particularly when the organic solvent is capable of enhancing the strength of the fibres. Suitably the initial scouring step is such that It does not cause i WO 89/12121 PCT/AU89/00250 8 fibre entanglement and/or breakage.

The preferred solvent in regard to the treatment step of the invention is 1,1,1, trichloroethane (TCE) for its relative cost and ease of recovery. A detergent is used to t ps improve TCE performance in cleaning dirty fibre4teps. This detergent may be any that is compatible with organic solvents such as an aliphatic liquid hydrocarbon.

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 some processing, batch processing may be more appropriate in terms of the capital cost of plant. For large 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 baskets that are dipped in a bath containing the solvent.

In fact it is particularly preferred to place the wool as an integral fleece in the dip baskets with the normally outer part of the fleece orientated (tip) downwards.

Where a continuous process is used, the fleece is preferably placed on a conveyor belt such as a perforated plastics or metal mesh belt such that the fleece travels preferably tip down through the solvent bath in a partly submerged and i submerged manner. Such a belt may need ribs or cleats to maintain fleece movement relative to the counter-current TCE solvent flow.. I If required the wool may be contained in a flexible iB i.

WO 89/12121 PCT/AU89/00250 mesh or perforated container to facilitate access to the wool by the TCE and removal of same from the wool.

The cleaning step using trichloroethane (TCE), methylene chloride, or mixtures thereof also results in superior drying performance of the wool.

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 essential to use a centrifugal or other type of spin drying step to achieve maximum physical solvent removal from tIF~3 tips the wool. This should be done preferably with the.-to*.s of the wool oriented outwardly or upwardly in the direction of solvent flow to achieve a flushing action for final removal of impurities. The wool is then dried to the optimum level required for either deburring if required or to that required for efficient carding and combing.

Suitably the wool may be rinsed in TCE or other organic solvent in the centrifuge or spin dryer to maximize removal of dirt or other impurities and traces of residual detergent.

In regard to one embodiment of the invention the wool after immersion in the aqueous scour normally leaves the final wash and passes through a wringer or other suitable mechanical dewatering step prior to drying. In relation to this invention the hot wool can preferably be taken straight from the dryer and immersed in TCE. The immersion time may be at least 2 minutes and need be no longer than 15 minutes depending on the method of agitation. The wool can be then i€ I BI WO 89/12121 PCT/AU89/00250 taken from the TCE bath and placed in a spin dryer. The i relatively high specific gravity of the TCE and the relatively open configuration of the wool fibres allows for quick and efficient removal of solvent from the wool.

Residual solvent levels of less than 2% on a dry wool weight basis can be achieved. The size of the spin dryer and the g forces are typically 200 to 400 but can be in the range 50 to 1000.

Alternatively wet aqueous scoured wool can be processed. The water carried from the aqueous scour into the TCE medium can be separated using conventional techniques exploiting the different specific gravities of TCE and water.

This thereby enables recycling of the TCE to be carried out with consequential minimisation of losses. This procedure is not however recommended.

In order to minimise costs 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 recycle rates throughout the process.

The solvent is recovered by distillation leaving the wool wax as a residue for further refining into valuable lanolin products. Solvent scouring maximizes recovery of wool waxtypically 95% recovery.

The unexpected advantage conferred by the present process on the scoured wool is the actual initial increase in the measured tensile strength of the wool compared to traditional aqueous scoured wool. This increase in scoured wool fibre strength is regarded as resulting in increased i i i WO 89/12121 PCT/AU89/00250 11 wool top fibre length after further processing a more valuable wool top product).

The mechanism by which this fibre strength increase occurs is associated with internal changes to the fibre subsequent to solvent penetration. These changes await biochemical elucidation though it is probable that appropriate solvent treatment causes a biochemical reaction with the cell membrane complex (CMC) of keratin. This complex is congruent with both cortical and cuticular cells.

It provides a matrix which is normally the weakest component of keratin. The complex consists of lipid and lightly crosslinked protein material and although it represents only a small proportion of keratin it is nevertheless important as it very largely determines the tensile strength of that keratin. Exposure ofthis CMC to appropriate solvent has, in our hands, led to an increase in tensile strength and this probably reflects changes which induce lipid (e.g.

cholesterol t iglycerides and free fatty acids) removal from the fibre in the initial period of contact. Eventually under ultra-sonic vibration extreme agitation conditions and occasionally under normal agitation conditions the i sphingolipids and phospho lipids may be extracted and this will lead to reduced fibre strengths after the initial strength increase period.

In the present invention the proposed solvents have a higher vapour pressure than water and both a lower specific heat and latent heat of vaporization. Therefore it takes less time and substantially less energy to dry the t ,i^ 'c -r i in *'C P.

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WO 89/12121 PC/AU89/00250 scoured wool. Even when the solvents of the present invention are used on wet wool after an aqueous pre scour, drying times and energies are considerably reduced by the formation of solvent/water hydrotropes when using specific aetergents active in a TCE solvent. This enables easy physical removal of the water content in the spin drying section of the sol at recovery process relative to water rxtraction alone. .iis water content of the hydrotrope is then recovered w. 'h the wool wax product in the solvent recovery distillation step.

Another advantage of the present invention is an improvement in the average colour of the scoured wool, from off-white for aqueous scoured wools to off white to very white for wools scoured in accordance with the present invention.

EXPERIMENTAL

Greasy wool staples were scoured so that twenty five individual staples forming each group to be tested were tested on AWTA (Australian Wool Testing Authority) certified testing device.

In accordance with Table 1 attached hereto the samples were averaged to provide a mean tensile strength for that treatment group. Table 1 identifies the extent to which trichloroethane (TCE) solvent and various treatment regimes can influence the tensile strength of aqueous scoured wool.

The tensile strength units are provided in neTrtons per kilotex. Paired samples were then tested after various immersion times in TCE and the results are provided as stated t i": t :i J i: ii t

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II~ WO 89/12121 PCT/AU89/00250 13 in Table 1. In this regard the samples were steeped in an open topped vessel and subsequently dried, before having their tensile strength measured as described above.

ft=' Wool staples were initially scoured using traditional aqueous scouring technology as described below.

These samples were processed as individual staples so that the tensile strength could be measured after scouring (aqueous control Table The Wool School at the Brisbane TAFE College kindly enabled us to use their traditional aqueou; scour system utilizing KLEENIT detergent (obtained from Campbell Bros. Ltd.) which is designed for the processing of small test batches.

After aqueous scouring the wool was dried in a forced hot air stream and half the staples condition to allow regain of moisture. All staples were then immersed in 1,1,1, trichloroethane solvent for various times (Table 1), air dried, conditioned and then tested for tensile strength.

Before testing the samples were spun dried in a centrifuge having a g force of approximately 300. The centrifuge utilized was a LIGHTBURN spin dryer serial no. 6504. Hence, there is described in. Tab-e 1 traditional aqueous scoured samples (aqueous control) and similar samples which have had an additional treatment by way of immersion in TCE. These samples were all measured for tensile strength and the following points summarize the major findings in relation to the treatment of aqueous scoured wool with solvent to increase tensile strength.

1. TCE treatment increases tensile strength of scoured I:'i i i::n i dirt from the wool, Soviet Patent No. 996532 discloses the use of ultrasonic agitation of the liquid scour medium in an attempt 1 WO 89/12121 PCT/AU89/00250 14 wool.

2. This effect takes place after a minimum immersion period of 2 minutes, 3. The preferred period of immersion is 2-3 minutes for violent agitation (ultra-sonics) and 6-10 minutes for gentle and normal agitation methods.

4. Immersion in methylene chloride or TCE methylene chloride mixtures also imparted the same result.

Immersion of aqueous scoured wool straight from the less i oven gave a slightlyiimproved tensile strength over that observed using dry, conditioned wool at room temperature.

Alternatively, wet wool taken from the final rinse bowl of an aqueous scour can be squeeze dried and then treated in TCE as above to achieve similar results (Table 2).

Increases in tensile strength can therefore be achieved by using a TCE immersion treatment either after this final rinse or after the drying process.

Also attac]'ed hereto are FIGS 1A, 2A, 2B,- 3 and 4A which illustrate the above described behaviour of wool treated in accordance with the invention. Thus FIG 1A illustrates wool treated with vigorous ultra-sonic agitation, FIGS 2A and 2B illustrate wool treated with normal agitation, FIG 3 illustrates an increase in wool tip quality achieved by the process of the invention, and FIG 4A illustrates a graphical analysis of results of fibre testing. I Reference may also be made to Table 3 which refers I i to testing of wool samples already illustrated above in FIGS '*I 2A, 2B and 3.

00 TABLE 1

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The effects of various TCE immersion times on the tensile strength of aqueous scoured dry wool with gentle agitation. c Treatment Strength (N/Ktex) H.

Greasy 30.6 27.8 Control O Aqueous 41.3 65.3 45.2* 45.2 35.4** 35.4 45.0 32.0 D Control TCE I min 46.0 472 37.8 TCE 2 min 53.0 56.3 39.9 (D P, TCE 3 min 49.6 52.9 55.8 44.6 r TCE 4 min 53.0 54.9 37.

TCE 5 min 50.1 84.0 59.8 61.4 51.7 53.8 54.0 45.0 32.5 So TCE 10min 49.1 83.6 61.1 60.3 54.0 55.0 48.6 35.6 35.8 TCE 15min 50.3 53.8 55.4 34.3 37.0 0 TCE 30min 44.0 35.1 47.4 TCE 60min 45.0 34.9 50.7 Figures in this column refer to the use of CH CI (methylene chloride) in lieu of TCE. Mixtures of 0 TCE:CH CI also provided a similar change in strength.

**Figures in this column represent the result of samples immersed in TCE immediately after removal from 0 0 oven iueVn.hscl.nrfrt..eueo...l mtyen hoie)i iuo TE itre f

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TABLE 2 The effects of various TCE immersion times on the tensile strength of aqueous scoured squeeze dried wool.

Treatment Strength (N/Ktex) Aqueous Control min TCE 20'C min TCE 40'C min TCE 60'C min TCE 75'C 45.2 59.0 55.4 56.0 65.3 74.8 75.2 36.2 45.8 46.1 Temperature measurements refer to temperature of final aqueous wash bowl.

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Wool samples used in TCE solvent scouring Certificate results on lots used) Sample No. Wool Type TABLE 3 fibre strength tests as per Figures 2A, 2B and 3 (AWTA Test as per F i b r e Diameter (mucron) 22.9 21.8 22.0 26.0 24.7 21.9 23.0 21.9 Table 1 Sample 7 Schlumberger Yield 70.9 70.3 73.2 67.9 71.4 71.4 76.8 71.4 F i b r e Fibre Strength (N/Ktex) 21 22 25 35 26 34 38 34 F i b r e Length (mm) Vegetable Matter 0.3 0.2 0.3 2.1 0.9 1.3 0.3 1.3 64 p ~J i. -L "'NT0 I WO 89/12121 PCr/AU89/00250 18 In the case of scouring the greasy wool with the solvent, it was further found that with ultrasonic vibration at 25kHz that the wool samples having an initial tensile strength of 35 N/Ktex increased to a peak of 56 N/Ktex after 2-3 minutes and then decreased to 40 N/Ktex after 20 minutes.

It is also pointed out that in addition to the chlorinated hydrocarbons preferably 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 solvent jets (from the sides and underneath) may be used for example in a bath arrangement or preferably large volume, low pressure solvent jets from above the submerged wool fibres. These jets may be used to replace the conventional agitation raking mechanism used in aqueous scouring processes thereby simplifying the apparatus or equipment recommended.

In another possible embodiment the wool scouring process could be carried out in large automatic washing machines using gentle agitation, soak, wash, rinse and spin dry cycles with water or solvents (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 special washing machine designed with gentle 1 1 1 :!i r i.

r i i-iii j~II i--.-li 1 i ZI WO 89/12121 PC"T/AU89/00250 19 agitation to minimize fibre entanglement would suitably have automatic valves to direct the solvent scour liquors and residues to a standard scour liquor treatment process for residue removal by filtration or centrifugation and then later to direct the solvent liquors to the solvent distillation and lanolin recovery processing steps.

The process of the invention may be applied not only to greasy wool requiring scouring but also used to treat dried or wet aqueous scoured wool as may be considered appropriate. The treatment with halogenated hydrocarbon may occur after aqueous scouring or can preferably be the actual scouring process.

It will also be appreciated from the foregoing that the term "wool" refers to animal hair generally and that the process of the invention can be applied to animal hair fibres inclusive of civet cat hair fibres, weasel hair fibres, raccoon hair fibres, astrakhan hair fibres, fox hair fibres, mink hair fibres, chinchilla hair fibres, sable hair fibres, angora and cashmere goat hair fibres, camel hair fibres and alpaca hair fibres.

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 i process of the invetion utilizing a continuous procedure; i A methods (including submersion ,nd jetting of the submersed wool with low pressure high solvent jets) the fibre strength L LUi ~ac~rMa~f~ll~~YBlir~ WO 89'12121 PCT/AU 49/00250 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 oreorganic solvent. c sseparate fleeces tc=e broken N So\ t fc-reovc\ Q.rs A re.c-o \n up into clumps of wool before/ Mt--s-c.oureI T-e. cS c= ve-

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S 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 stak of separate fleeces aqueous scoured wool or greasy wool) which are placed tip down in baskets 11 carried by conveyor 12 having head rollers 13, tail rollers 14, and intermediate iF.ler rollers 15 approaching tip pre treatment zone 16 in scouring i tank 9, which is defined by downward ramp 17, level portion 18 and upward ramp 19. The tips of the fleece may be i subjected to gentle cleansins action as described previously.

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h: .1 iPCT/AU9/00250 PCT/AU89/00250 WO 89/12121 The remainder of each fleece does not contact the scouring medium 20 which ray 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 containing halogenated hydrocarbon which is retained in bath 9. The contact time is as described previously and is preferably 6-10 minutes.

There are also provided drains 26 and 27 wherein spent scouring medium may be passed for filtration and further purification. Also shown is manifold 23A for application of detergent to scouring bath 20. After passing through scouring zone 23 the baskets 11 are conveyed up upward ramp 28 which includes manifold 28A for applying fresh solvent as a rinse before fleeces 10 are passed to unloading zone 29 wherein the fleeces 10 are unloaded into centrifuge 30 for 20 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 i include carding for example.

Conveyor 31 is controlled by head roller 31A, tail roller 31B and intermediate idler rollers 31C as shown.

solvent flow..

If required the wool may be contained in a flexible 'i' WO 89/12121 PCT/AU89/00250 22i In FIGS 3A, 3B and 3C there is shown a plurality of i fleeces 10 (aqueous scoured wool or greasy wool) 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. The fleeces are conveniently separated by ribs 37A (only a small number of ribs are shown for the purposes of clarity, but it will be appreciated that ribs 37A are attached to conveyor 37 along the entire length thereof).

A 10 The zone 38 includes skimmer box 39, pump 40 and agitation s: ys 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 cleiring 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 comprises halogenated hydrocarbons or halogenated ethers as described previously and wherein the contact time is 6-10 minutes. Scouring zone 45 also includes skimmer box 39 and pump 40. Agitation sprays 41 are also utilized in scouring zone 45 which also includes idler roller 44 as well as manifold 45A for application of detergent.

The fleeces 10 may then be subsequently passed through a rinsing zone 46 which is defined by upward ramp 47 of conveyor 37. In rinsing zone 46 fresh recycled solvent is applied to fleeces 10 to remove residual traces of impurities through manifold 46A. There is also included separator 48 separtor I be at least 2 minutes and need be no longer than 15 minutes depending on the method of agitation. The wool can be then

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f WO 89/12121 PCr/AU89/00250 23 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 dearbox 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 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 f 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

I

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 i il:te i 1 J l a traditional aqueous scoured wool. This increase in scoured wool fibre strength is regarded as resulting in increased WO 89/12121 PCT/AU89/00250 24 and 27 wherein spent or dirty solvent is passed through line 68 to pressure filter 69 before reaching distillation vessel The pressure filter 69 may be precoated with diatomite, 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 turther refining.

Cooling water may be passed through condenser 72 through lines 75 and 76.

Claims (14)

1.A proces s for treating animal fibres which include the steps of: contacting said animal fibres for an optimum contact time of 2-15 minutes in an organic solvent to increase the fibre strength thereof; and (ii) removing said organic solvent to provide animal fibres suitable for carding and/or topmaking. characterised in that steps and (ii) are carried out<. Ll .L.

2. A process as claimed in claim 1, wherein the optimum contact time has an upper limit of 10 minutes.

3. A process as claimed in claim 1, wherein the optimum contact time has an upper limit of 5 minutes.

4. A process as claimed in claim 1, wherein the contact time has a lower limit of 2-3 minutes where extreme ultrasonic agitation is employed.

5. A process as claimed in claim 1, wherein said treatment with solvent is preceded by an initial aqueous scouring step.

6. A process as claimed in claim 1, wherein the solvent is halogenated hydrocarbons or halogenated ethers.

7. A process as claimed :i claim 6, wherein the solvent is 1,1,1 trichloroethane.

8. A process as claimed in claim 1, wherein during the removal step the anim al fibres are subjected to drying in a spin dryer or centrifuge.

9. A process as claimed in claim 1, wherein during said optimum contact time said animhl fibres ar e treated with C S 00 C CeSS S 0S4~0 @055 CO 5* 9 CC *S CC Sc .4 detergent.

A process as claimed in claim 9, wherein said animal fibres are rinsed with fresh or unused organic solvent after immersion with said organic solvent.

11. A process as claimed in claim 1, wherein spent organic solvent recycled from said contact with said animal fibres has a residual animal hair grease substance content of less than 3%.

12. A process as claimed in claim 11, wherein said residual animal hair grease substance contact is between and

13. A process as claimed in claim 1 including the steps of: 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 for said optimum contact time to improve the fibre strength.

14. A process as claimed in claim 13, wherein the plurality of masses of animal fibres are combined in an aggregate prior to carding. DATED this twenty-sixth day of April 1991. WOOL CLEANING TECHNOLOGIES LIMITED By Their Patent Attorneys CULLEN CO S 0 i;0 V- 'A i^' L^ \v 'x'TOX V X/VT