NZ243362A - Felt-free finishing process for wool using highly acid potassium permanganate - Google Patents

Description

24 3 3 6 j """ ' Cl?ss: Pi!h'ic-*:-.rt f.. ,., [[li'ftMm J P.O. J. - .. ,1^0 NEW ZEALAND PATENTS ACT, 1953 No.: Date: COMPLETE SPECIFICATION PROCESS FOR THE FELT-FREE FINISHING OF WOOL We, SCHOELLER HARDTURM AG, a Swiss company, of Hardturmstr. 122, 8005 Zurich, Switzerland, hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- - 1 -(Followed by page la) la- f C f 3 3 6 2 The present invention relates to a process for the felt-free finishing of wool or wool fibres, respectively.

It is generally known that during washing or generally during an extended contact with water, wool gradually starts to become felted, i.e. the individual fibres in woollen fabrics lose their elasticity and become frizzy and the textile material is compacted. For this reason woollen articles must either be chemically cleaned, or must be washed extremely gently - undoubtedly unfavourable prerequisites in a time where it should be possible to wash all articles as universally and problem-free as possible in the washing machine.

For this reason the number of known felt-free finishing processes of wool or wool fibres respectively are many, and the most widely used and best known finishing process is undoubtedly the so-called Chlorine Hercosett process, which is applied mainly to combed wool tops, and the use of which gives good felt-free finishing results. A detailed evaluation of this process can be dispensed with, as this process is very well known in the branch in question and from the corresponding literature. For environmental reasons the chlorination of the wool fibres carried out in the first phase of this process is becoming increasingly problematical, as the waste water resulting from the chlorination phase contains absorbed chlorine compounds, so-called AOX substances (= Absorbable, Organic Halogen compounds). The conditions imposed by the legislator for the future with regard to the admissible amount of AOX of chemical installations are such that the further use of the Chlorine-Hercosett process is to be questioned. Another disadvantage of this process lies in the use of a polyamide resin in a further process phase, carried out to reinforce the felt-free effect and to protect the stem of the wool fibres treated with chlorine.

Against the background of these disadvantages, the enzyme treatment of wool was developed, in which connection reference is made to the article by H.R. Haefely, Textilveredlung 24, (1989), 7, 8, pages 271 -276. It is true that by means of this "enzyme process", the use of the undesirable polyamide can be dispensed with, but in practice it was found that, as before, a first phase chemical pre-treatment of the wool is necessary, even though with a greatly reduced effect.

It is, therefore, an object of the present invention to propose a felt-free finishing process, the efficiency of which in respect of the felt-free finishing corresponds to that of the known processes, but with which a chemical pre-treatment by means of chlorine can be completely dispensed with.

According to the invention this object is achieved by means of a process in accordance with the wording of claim 1. According to the invention it ie> proposed that for the felt-free finishing the wool or wool fibres, respectively, should be treated for a period of less than one minute with an essentially highly acid, aqueous solution of potassium permanganate.

It is known from the past to use potassium permanganate in an alkaline solution or also together with sodium hypochlorite for the felt-free finishing of wool. However, such potassium permanganate based processes were largely replaced by the Chlorine-Hercosett process, because, whilst the wool was treated as gently as possible, the felt-free finishing effect was too weak. Evidently, the oxidizing effect of the potassium permanganate in an alkaline medium or together with sodium hypochlorite does not suffice to finish the wool or wool fibres in such a felt-free way that they meet the presently demanded standards in respect of the washing thereof. An attempt was made, it is true, to also use potassium permanganate in an acid medium, but the felt-free finishing effect was such that with an adequate felt-free finishing the fibres got too badly damaged.

According to the invention and surprisingly it has now been found that when using an appropriate, moderately concentrated, highly acid (pH < 1), aqueous potassium permanganate solution and an extremely short treatment time of the wool or wool fibres, these can be finished felt-free in accordance with the known and demanded standards, without the fibre stem being damaged.

With this, the concentration of potassium permanganate in the reaction solution preferably is 0,5 - 3 gr of potassium permanganate per litre 24 3 3 6 2 of solution, whereas the concentration of industrial concentrated sulphuric acid (62*) is 15 - 40 gr per litre of solution.

The treatment time or the contact time of the aqueous potassium permanganate solution with the wool or the wool fibres is 5 - 20 seconds, preferably 5-10 seconds.

Further preferred process conditions are characterized in the claims 2 to 8 .

When using the process defined according to the invention it was found that, depending on which wool quality or wool origin is being treated, it may be advantageous when the short-time treatment with a highly acid, aqueous solution of potassium permanganate is carried out repeatedly, in which case the wool or wool fibres must after every treatment be treated or cleaned with a reducing agent, e.g. sodium sulphite, to remove the formed brownstone.

Furthermore it is proposed that the felt-free finishing of the wool or wool fibres preferably takes place in that they, preferably in the form of combed wool tops, together with an essentially highly acid, aqueous potassium permanganate solution, are fed through a substantially closed through-run trough or a through-run channel with inlet and outlet opening. Important, respectively essential in this connection is that the packing density of the combed wool tops in the through-run trough or channel is such that the reaction solution is moved along substantially at a constant speed relative to the combed wool top. In accordance therewith, preferably a bath ratio of 6 -9 1/kg wool is used in the through-run trough.

A suitable, preferred embodiment variant of such a reaction process or such a felt-free finishing of wool or wool fibres is characterized by the wording of one of the claims 11 or 12.

To perform the abovementioned preferred embodiment variants according to the invention, an apparatus is proposed in accordance with the wording of claim 13.

To perform the substantially continuous felt-free finishing of the wool by means of the reaction solution according to the invention, a reaction apparatus is proposed which is characterized by: a drawing-in device for the drawing in of the wool or the combed wool top and the charging with the reaction solution according to the invention, and following the drawing-in device, a substantially closed through-run trough or through-run channel with inlet and outlet opening, through which the to be treated material is fed together with the reaction solution.

Preferred embodiment variants of the apparatuses according to the invention for performing the process according to the invention are characterized in claims 14 to 18, and claim 19 describes an arrangement for the felt-free finishing which uses at least one of the said apparatuses. - 6 v* v* In the following the invention will be explained in greater detail with reference to the attached figures, wherein: Fig. 1 shows in longitudinal section a through-run channel according to the invention; Fig. la shows the through-run channel of Fig. 1 in cross-section along the line I-I; Fig. 2 illustrates another through-run channel shown in longitudinal section; Fig. 3 is a longitudinal section through a semi-circular through-run channel, formed by a trough-type container with a rotating body arranged inside same; Fig. 4 shows the apparatus according to Fig. 2 in cross-section along the line II-II; and Fig. 5 shows in longitudinal section two apparatuses according to Fig. 3 arranged next to one another.

Fig. 1 illustrates in longitudinal section and diagrammatically how the reaction of the felt-free finishing of wool or combed wool tops according to the invention takes place in a through-run trough or a closed through-run channel according to the invention. 2 For the felt-free finishing of a combed wool top 1, beforehand a highly acid, aqueous potassium permanganate solution is produced in a separate mixing tank or tube 5. To this end an aqueous potassium permanganate solution 2a, together with an aqueous sulphuric acid solution 2b, containing a wetting agent, e.g. ethylene oxide adducts, are introduced into the mixing tank 5 and mixed briefly to form a homogeneous reaction solution 7. This is subsequently fed immediately to a drawing-in tank 3, where the solution 7 is brought into contact with the combed wool top 1. It is important that the sulphuric acid solution 2b containing the wetting agent is combined and mixed with the potassium permanganate solution 2a only shortly before the contact with the combed wool top 1, because the potassium permanganate relatively quickly has a negative effect on the efficacy of the wetting agent or oxidizes same. On the other hand, if the sulphuric acid solution 2b and the potassium permanganate solution 2a were to be fed directly into the drawing-in tank 3, this would be unfavourable in so far that in this case the homogeneity of the solution is not perfectly ensured, as a result of which the uniformity of the finishing process of the wool would not be ensured.

In a preferred, selected exemplified embodiment a potassium permanganate solution 2a was used with a concentration of 50 gr KMn04/l. The concentration of the added sulphuric acid solution is 35 gr industrial concentrated sulphuric acid (62*) per litre of solution. In the chosen example, the mixing ratio between the flows 2a and 2b is 1:18. A polyphosphonic acid may be added to the acidifed potassium permanganate, in the range of between 1.5-4.5g of polyphosphonic acid per litre of potassium permanganate solution. In this regard,in a further example, in addition bpprox. 2 gr/1 of a polyphosphonic acid was added to the sulphuric acid solution. This *? v \J U &» 24 3 3 6 ?. prevents the precipitation of brownatone (Mn02), as a result of which a correct surface treatment becomes really possible.

The combed wool top 1 is now guided via a, for example, driven carrier roller 9, together with the reaction solution through an inlet opening 11 into a closed through-run channel 13, which, as illustrated in Fig. la, has a rectangular cross-section. To ensure a proper wetting of the wool during the drawing-in into the through-run channel 3, as indicated above, the solution is preferably mixed with a commercial wetting agent. As the packing density of the combed wool top in the through-run trough 13 is relatively great, the reaction solution 7 together with the combed wool top are moved simultaneously to the outlet opening 15 of the through-run trough or closed channel. In the present example the packing density is about 100 gr wool per litre of channel volume, and the selected bath ratio is approx. 6,5 1 reaction solution per kg of wool.

On leaving the through-run trough or closed channel 13 at the outlet opening 15, the combed wool top 1 is drawn off via take-off rollers 17 and at the same time the reaction solution present in same, and which has finished reacting, is squeezed out. The reaction solution which also comes out of the trough 13 passes via en edge 19 into a collecting tank 21, in which the spent reaction solution 23 is collected. This is subsequently either re-concentrated via a pipe 25 and fed back to the drawing-in tank 3, or is used elsewhere, or it is dis charged into the waste water after having been neutralized.

O 3 6 2 Because the reaction solution 7 is constantly moved along through the through-run trough or closed channel 13, fresh reaction solution 5 must continuously be fed to the drawing-in tank 3, which, also without a suitable regulation, will ensure a largely constant concentration gradient throughout the entire apparatus. Furthermore, because of the relatively high packing density of the to be treated combed wool top in the through-run trough, a constant bath ratio is ensured along the entire reaction zone. In the chosen example the quantity of reaction solution 7 fed continuously to the drawing-in tank 3 is about 4,4 1/ minute, whereas at the same time 656 gr of wool per minute are fed through the through-run trough 13.

It now speaks for itself that the reaction time or the contact time of the reaction solution with the wool can be influenced by the length of the channel or the trough 13 and/or by the speed at which the combed wool top 1 is moved through the trough or the channel 13. Thus, for example, the contact time or the reaction time may be only a few seconds, e.g. 5-10 seconds.

A further advantage of the apparatus according to the invention is that the volume of the reaction solution can be kept very small, i.e. per 1 kg of combed wool top one can, for example, work with a treatment bath with a volume of 5 - 12 1. This value naturally depends on the packing density in the through-run trough.

What is important for the felt-free finishing according to the invention is that the wool or combed wool top is wetted completely with the * "7 "jF V v? 6 2 solution of chemicals at the inlet or in the drawing-in tank, and that while the wool passes through the closed channel to the outlet opening 15, the reaction takes place to such an extent that the chemical treatment of the outer layer of the individual wool fibres, or wool hairs, the so-called cuticle, is completed in as far as possible in accordance with the requirements for a felt-free finishing, whereas the actual fibre stem or the cortex has not yet been attacked by the reaction solution. For an as uniform a6 possible felt-free finishing of the wool, it is also important that the bath ratio can be kept constant along the entire channel, to which end it is necessary that the supply of reaction solution 7 or bath corresponds to the amount of fed-in combed wool top 1. By a correct choice of the packing density, it can furthermore be ensured that the rate of flow of the bath relative to the wool inside the channel 13 can be kept constant.

During the felt-free finishing reaction described above, it may now and then be possible that manganese oxide or so-called brownstone is formed in the bath, which is precipitated and may deposit itself, for example, in the combed wool top and in the treatment apparatus. It is true that it has been found that by using sulphuric acid in combination with polyphosphonic acid products the formation of brownstone in the bath is greatly reduced. Nevertheless it is necessary that, following the reaction stage described above, the combed wool top is subjected to an after-treatment, which can be done in the known manner by means of reducing agents.

* T T £ . 4 J o 0 Now and then, depending on the nature of the wool quality and the nature and quantity of the accompanying fibrous substances, the brown stone formation on the wool may even cause the felt-free finishing to be inadequate, because the reaction with potassium permanganate is impeded. It may, therefore, be advantageous when the short-time treat ment with a highly acid potassium permanganate solution is applied repeatedly, e.g. by arranging several of the apparatuses according to the invention behind one another, as illustrated in the figures. In that case a cleaning stage will always have to be provided between every two felt-free treatment processes, in which stage the cleaning or "washing out" of the brownstone takes place by means of the usual reducing agents, e.g. by means of sodium bisulphite.

The reaction apparatus according to the invention, illustrated in Fig. 1, can also be used, by the way, to treat any textile or also non-textile, fibre-like lengths or strands with a reaction solution which has a high reaction speed with the to be treated textile or non-textile material. What is important here is that the reaction is limited to only the outer layer of the fibres or the individual fibrillae of the textile or non-textile material, but that, for example, as mentioned above, the fibre stem (cortex) is not attacked by the reaction solution.

The reaction apparatus according to the invention, illustrated in Fig. 1, also has the great advantage that no pumping or feeding devices need to be provided to convey the reaction solution, since 24 3 3 6 2 as a result of the set packing density this is moved along by the moving through of the to be treated textile material. Fig. 1, for example, shows clearly that the overflow edge 19 at the end of the apparatus is positioned at a considerably higher level than the reaction solution in the drawing-in tank 3. If, for example, the packing density is chosen too small, or if the through-run trough is not closed, the reaction solution would continually flow backwards and a moving along of the reaction solution together with the textile material would not be possible at all.

Fig. 2 again shows another embodiment of a proposed reaction trough or closed channel 13 according to the invention, wherein the through-run trough is no longer arranged in a straight upward line, but is semi-circular in the conveying direction of the to be treated combed wool top 1. The drawing-in tank as well as the take-off device are constructed substantially the same as with the apparatus of Fig. 1, but at the end of the through-run channel 13 of Fig. 2 a collecting tank 15 is provided, with a discharge channel 19.

The advantage of the reaction apparatus according to Fig. 2 is that as a result of the very large radius of curvature of the through-run trough 13, the friction of the combed wool top 1 is greatly reduced. The friction, caused by the pulling effect of the rollers 17, can be reduced further by providing longitudinal grooves in the walls of the through-run trough 13.

Fig. 3 shows another preferred embodiment variant of the apparatus according to the invention of Fig. 2, again in longitudinal section. This apparatus comprises a trough-like tank 12 with semi-circular bottom, the bottom being largely orbicular. Let into the stationary trough 12 is a closed rotating body 41, the axis of rotation 43 of which is arranged in the centre point of the circular bottom of the trough 12, and is connected to the trough in such a way that the rotating body 41 can rotate freely. Here, it is important that the radius r of the rotating body 41 is smaller than the inside radius R of the tank bottom 10. By arranging the rotating body 41 in the trough 12, the peripheral surface 45 of the rotating body 41 and the inside surface of the bottom 10 of the trough 12 form the described through-run trough or closed channel 13 according to the invention, which in turn ensures that the combed wool top 1 can be moved from the inlet opening 11 to the outlet opening 15. At the end the trough 12 is provided, in front of the inlet opening 11, with a protruding part 3 which forms the drawing-in tank, and behind the outlet opening 15 an overflow edge 16 or overflow channel 19 is provided to discharge the reaction solution. For the rest the mode of operation of the rotary apparatus according to Fig. 3 is analogous to that of the apparatus according to Fig. 1.

In Fig. 4 the rotary apparatus according to Fig. 3 is shown in cross-section along the line II-II, from which it can clearly be seen that the rotating body 41 is arranged in the trough-like tank 12 in such a way that it practically fills out the latter, but nevertheless can T /r* -1" - V 'i 5 o rotate freely. At the bottom end of the rotating body 41 the through-run trough or closed channel 13 can be seen, through which the wool 1 is fed.

Depending on the nature of the material to be treated or fed through, it may suffice when the rotating body 41 is freely rotatable. If the combed wool tops 1 are very loose or tear easily, it is possible to drive the rotating body 41 or the rotary drum 41 synchronously with the take-off rollers 17. Furthermore it is possible to provide the surface 45 of the drum 41 with transverse grooves, whereas the bottom 10 of the trough-like tank 12 preferably has longitudinal grooves. Finally, for cleaning purposes it is advantageous to arrange a discharge device 14 at the bottom end of the trough 12, so that the trough or the channel 13 can be emptied.

The apparatus according to Fig. 3 and 4 can be operated under substantially the same reaction conditions as mentioned with reference to Fig. 1. Basically, the same requirements and reaction conditions apply as mentioned under Fig. 1. In addition, reference is made to the following example: Example of a 1:1 prototype of a rotary apparatus according to Figures 3 and 4 for the carrying out of operational tests.

To carry out operational tests for the felt-free finishing of combed wool tops, a prototype was used with the following dimensions: .'3362 r = 50,0 cm; R = 51,2 en; resultant height of the reaction channel 13: 1,2 cm; width of the rotating roller or the rotor 41: 61,3 cm; length of the reaction channel: 122 cm (the channel extends over an angle section of 138,5"); cross-section of the reaction channel: 75,7 ci:.

In the longitudinal section according to Fig. 3 one has the following areas: inlet area according to reference numeral 3: 170 cm'; through-run trough or channel 13: 147 cm2; outlet area according to reference numeral 16: 31 cm1.

For test purposes a combed wool top was used with the following characteristics: number of individual bands: 36; mass of one individual band: 20 g/m; mass of the complete combed top: 720 g/m; immersion length of the combed top in the apparatus according to Fig. 4: 155 cm, of which 24 cm in the inlet area, 122 cm in the reaction channel and 9 cm in the outlet area. fleece weight in the immersion area: 1,12 kg; fleece volume in the immersion area: 0,86 1; fleece weight in the reaction channel 13: 878 g; fleece volume in the reaction channel 13: 0,68 1; combed top density in the channel area 13: 0,095 g/cm3. 24 3 3 5 Finishing tests were carried out under the following conditions: bath volume without combed top: 21,4 1 bath volume with introduced combed wool tops: 20,5 1; bath volume without wool in the reaction channel 13: 9,28 1; bath volume in the reaction channel 13 with introduced combed top: 8,6 1.

This results in the following bath ratios: related to the overall plant: 18,3 1/kg of wool; related to the reaction channel 13: 9,8 1/kg of wool.

Operating conditions of the apparatus: Table 1: 1 | Combed top j speed | (m/min) Combed top throughput (kg/min) Bath throughput (1/min) 1 Dwell-time | immersion area | (sec) j I 4,0 2,88 22,5 23,2 | I 5,0 3 ,60 28,1 18,6 | 1 6,0 4,32 33 ,7 ,5 | 1 7,0 ,04 39 ,3 13,3 | I 8,0 i ,76 44,9 11,6 | i The speed ratio of combed top to reaction bath is largely constant. 24 3 3 6 2 Number of revolutions of the rotary rotor 41 {circumference = 3,14 m) : Table 2 1 - - | Combed top 1 Number of | | speed revolutions | | (m/min. ) (-/min) | 1 4,0 1 ,27 j I 6,0 1,91 | | 8,0 i 2,55 | i With the operating conditions indicated in the foregoing and the proposed apparatus according to the invention, combed wool tops were finished felt-free with various oxidizing agent solutions, e.g. with permanganate solution, etc., in accordance with the process defined by the invention. In the final analysis, it is a question of optima-tion, taking into account the selected oxidizing agent, the selected concentration, the set pH-range, etc., how the apparatus according to the invention is to be operated or how the operating data are to be chosen.

Also the apparatus according to Fig. 3 and 4, the same as the apparatus according to Fig. 1 and 2, can be used universally anywhere where a textile or non-textile material is to be treated briefly with a highly reactive reaction solution, wherein the reaction may take place only at the surface of the material.

Fig. 5 shows in longitudinal section two apparatuses according to Fig. 4 arranged behind one another. Via the drawing-in or the protruding part 3, the combed wool top 1 is immersed in the reaction solution 7 and pulled into a first semi-circular reaction channel 13a through the inlet opening 11. This through-run channel 13a is formed by a first tank 12a comprising a semi-circular bottom and the corresponding rotating body 41a rotating therein around the axis of rotation 43a. After passing through this first reaction channel 13a, the combed top is guided over a shoulder 51 into an adjoining reaction channel 13b, which is formed in the same way by a second tank 12b comprising a semi-circular bottom and the corresponding rotating body 41b rotating therein. The same as with the apparatus according to Fig. 3, the combed wool top leaves the through-run channel 13b via the outlet opening 15 and is drawn off by the take-off rollers 17, in which the reaction solution is squeezed out. The reaction solution itself is discharged via the overflow edge 16.

By arranging such semi-circular tanks behind one another, it is possible to considerably increase the throughput speed of the combed wool top and at the same time to keep the contact time constant by making the reaction path longer. Naturally, depending on the requirements and circumstances, it is also possible to arrange three or more such apparatuses behind one another. The same also applies, of course, to the apparatuses illustrated in the Figures 1 to 4.

If necessary, it is even possible to arrange a cleaning process between the various apparatuses arranged behind one another, by means 243362 of which any occurring brownstone can be removed from the wool, e.g. with sodium bisulphite solution. Naturally it is also possible to use any other reducing agent to remove the brownstone from the wool.

Following the reactions in Fig. 1 to 5, it is possible, of course, to treat the combed wool top with a synthetic, preferably polyamide resin of silicone elastomers, or an enzyme, in accordance with the known processes, to further improve the freedom from felt of the woollen material. The diagrammatic reaction process illustrated in Fig. 1 to 5 can, of course, be changed, varied or modified in any way. In the final analysis it is a question of optimation whether the potassium permanganate and sulphuric acid concentrations of the reaction solution are chosen higher, whilst the reaction time is shortened, or whether a less concentrated solution is used whilst the reaction time is increased accordingly. Also the selected temperature is in the final analysis a question of optimation. The essential feature of the invention is that the woollen material is treated briefly with an essentially aqueous, relatively highly acid potassium permanganate solution, wherein the reaction solution preferably contains a wetting agent.

The reaction apparatuses illustrated by way of example in Fig. 1 to 5 may, of course, be changed or modified in any way. It is possible, for example, to make the through-run channel round by constructing the walls of the apparatuses accordingly. Also the c\rawing-in and take-off zones of the apparatuses according to Fig. 1 to 5 can be modified in any way, as this concerns customary conveying or feeding 3 3 6 2 and take-off techniques which do not form part of the present invention. Also the mixing and feeding of the reaction solution, as well as the discharging thereof, the possible re-concentrating or regulating of the concentration in the reaction solution is a known technique and further details thereof are also not given in the present invention. It is also possible to make the described apparatuses according to the invention of any materials, in which connection preferably transparent plastic materials are used, e.g. polyacrylate, polycarbonate or polyamide, wherein the material that is used must, of course, have an adequate chemical resistance to the chosen reaction solutions. However, it is also possible, of course, to make the apparatuses of stainless steel, aluminium, glass or other materials.

Claims (22)

243362 WHAT«tfWE CLAIM IS

1. a process for the felt-free finishing of wool or wool fibres, characterized in that the wool or wool fibres, respectively, is/are treated for a period of less than one minute by means of an aqueous solution of potassium permanganate having a pH of lower than 1.

2. a process according to claim 1, characterized in that the treatment of the wool or wool fibres, is carried out with an aqueous solution (pH < 1) of potassium per manganate with a concentration in the range of 0.5- 3 gr of potassium permanganate per litre of aqueous solution.

3. A process according to any one of the claims 1 or 2, characterized in that the aqueous solution of potassium permanganate for the treatment of the wool or wool fibres, is mixed with concentrated sulphuric acid, wherein the concentration of sulphuric acid in the solution lies in the range of 15 - 40 gr of concentrated, industrial sulphuric acid (about 62% by weight) per litre of solution. - 22 -

4 . a process according to any one of the claims 1-3, characterized in that, prior to the treatment of the wool or wool fibres, 1.5 - 4.5 gr of a polyphosphonic acid per litre of potassium permanganate solution is added to the aqueous solution of potassium permanganate, before or at the same time as the potassium permanganate solution is acidified.

5 . a process according to any one of the claims 1-4, characterized in that for the production of the aqueous solution of potassium permanganate for the treatment of the wool or wool fibres, shortly before the treatment approximately 1 part by weight of an aqueous solution of potassium permanganate with a concentration of about 50 gr/1 of solution is mixed with approximately 18 parts by weight of an aqueous solution of about 35 gr of industrial concentrated sulphuric acid (about 62% by weight) per litre of solution.

A process according to any one of the claims 1-5, characterized in that the treatment time or contact time of the aqueous, highly acid potassium permanganate solution with the wool or wool fibres, is 5 - 20 seconds.

7. A process according to any one of the claims 1-6, characterized in that the felt-free finishing of the wool or wool fibres, with the aqueous potassium permanganate solution takes place in a bath ratio in the range of 5 - 12 1 of solution per kg of wool or wool fibres, respectively.

8 . A process according to any one of the claims 1-7, characterized in that the felt-free finishing of the wool or wool fibres, takes place at a temperature of 20°C to 40UC.

9• a process according to any one of the claims 1-8, characterized in that the treatment for a period of less than one minute with an aqueous solution of potassium permanganate having a pH of less than 1 is carried out repeatedly, and after every treatment the wool or wool fibres, is/are cleaned with a reducing agent to remove the formed brownstone.

10. A process according to any one of the claims 1-9, characterized in that, following the felt-free finishing, the wool or wool fibres, is/are subjected to an after-treatment with a synthetic resin or silicone elastomers, or is/are treated enzymatically. - 24 - 243362

11. a process for the felt-free finishing of wool or wool fibres, characterized in that the wool or wool fibres, respectively, are fed, together with a reaction solution consisting substantially of an aqueous potassium permanganate solution having a pH of lower than 1, via a drawing-in device into a substantially closed through-run channel with inlet and outlet opening, are guided or moved through the channel together, and after the outlet opening are separated again and drawn off by suitable means.

12. A process as claimed in claim 11 wherein the wool or wool fibres are fed in the form of combed wool tops.

13. A process according to claim 12, characterized in that the combed wool top and the reaction solution are guided or pulled through a substantially closed channel or trough, wherein the trough or channel is formed by a stationary, substantially semi-circular, substantially orbicular, trough-shaped tank, with, arranged in the trough, a freely rotatable rotating body; the radius of which is smaller than the inside radius of the trough-shaped tank, and the width of which is the same as the inside width of the trough-shaped tank, so that between the peripheral surface of the rotating body and the inside tank bottom, an at least in the longitudinal direction substantially semi-circular, substantially closed channel or a trough with rectangular cross-section is formed, and wherein whilst the combe'd wool top together with the reaction solution are guided or moved through the closed channel or trough, the freely rotatable rotating body is rotated substantially synchronously to the conveying speed of the combed wool top.

14. An apparatus for performing a process according to any one of the claims 1-13 for the substantially continuous felt-free finishing of wool which together with a reaction solu tion is moved through a reaction apparatus, characterized by: - a drawing-in device for the drawing in of the material and the charging with reaction solution, and - following the drawing-in device, a substantially closed through-run trough or through-run channel with inlet and outlet opening for the feeding through of the to be treated material together with the reaction solution^

.An apparatus for performing a process according to any one of claims 1 to 13 for the substantially continuous treatment with a reaction solution of a material fed through a reaction apparatus, characterized by: - a drawing-in device for the drawing in of the material and the charging with reaction solution, and - following the drawing-in device, an elongated through-run trough or through-run channel with, arranged substantially at the ends, an inlet and outlet opening for the feeding through of the to be treated material together with the reaction solution, wherein the trough or channel is closed ' substantially on all sides, substantially

/ T ""p PS q oo o2 along the entire length, to be able to adjust a specific packing density, bo that as a result of the moving through of the textile material, the reaction solution is moved through the through-run trough or through-run channel. 16 .An apparatus according to any one of the claims 14 or 15 characterized in that the trough or channel is elongated, with a sub stantially uniform cross-section along the entire length of the trough or channel, wherein the cross-section of the trough or channel is round, square or substantially rectangular, and in that in front of the trough or channel a drawing-in tank is provided for the drawing in of the material and the charging with reaction solution and behind the channel or trough a collecting tank to collect or discharge the reaction solution, as well as take-off means for drawing off the material or for its further transport to a further treatment stage. 17.An apparatus according to any one of the claims 14 to 16/ characterized in that the trough or channel is formed by a stationary, substantially semi-circular, substantially orbicular, trofcgh-shaped tank with, arranged in the trough, a freely rotatfcble rotating body, the radius of which is smaller than the inside radius of the troijijgb^^ shaped tank and the width of which is substantially the same as the inside width of the trough-shaped tank so that between the peripheral surface of the rotating body and the inside tank bottom; an at least in the lon gitudinal direction substantially semi-circular, substantially closed channel or a trough with rectangular cross-section is formed.

An apparatus according to any one of the claims 14 - 16 characterized in that the trough or channel is formed by two or more successive stationary, substantially semi-circular, substantially orbicular, trough-shaped tanks, with, arranged in each trough, a freely rotatable rotating body, the radius of which is smaller than the inside radius of each of the trough-shaped tanks, and the width of which is substantially the same as the inside width of each of the trough-shaped tanks, so that between the peripheral surface of the rotating bodies and the inside tank bottom, an at least in the longitudinal direction substantially semi-circular, substantially closed channel or a trough with rect angular cross-section is formed.

An apparatus according fo any one of the claims 17 or 18, characterized

' '? E C 28 in that the rotating body ia driven in the conveying direction of the wool moved through the trough.

20. An arrangement for the felt-free finishing or wool or wool fibres, comprising at least one apparatus according to any one of the claims 14 - 19, wherein the apparatus or at least part of these apparatuses are provided with a cleaning device for cleaning the treated wool, suitable, for example, for removing brownstone, arranged behind the apparatus or between two successive apparatuses.

21. process for the felt-free finishing of wool or wool fibres substantially as herein described with reference to the examples.

22. An apparatus for felt-free finishing of wool or wool fibres substantially as herein described with reference to the accompanying drawings. A J PARK & SOM