NZ521591A - Oxidising treatment of a fibrous textile mass such as wool that can be given in the form of a web capable of being traversed homogeneously by a gas such as ozone and/or oxygen - Google Patents

Abstract

A method for oxidising a textile mass is described, in particular woollen, to modify the surface of the fibres whereof it is formed, consisting of: a) transforming said textile mass into a textile mass containing 12.5 to 60 % (g/g) of water and having a structure such that a gas can pass through it uniformly and thoroughly; and b) passing through the mass, for 5 to 20 minutes at room temperature, a gas mixture containing 20 to 150g of ozone per m3, which is continuously injected through the mass while it moves along on a carrier system, being alternately directed on both surfaces of each pass. Such treatment is preferably carried out in a sealed chamber, the ozone being destroyed in output.

Description

5215 91 Process for oxidizing or activating a fibrous mass with a gaseous mixture containing ozone The invention generally relates to the oxidizing 5 treatment of any fibrous mass that can be given the form of a web capable of being traversed homogeneously and completely by a gas.

A fibrous mass is to be taken here as meaning any mass of fibers of animal, vegetable or synthetic origin. 10 The oxidizing treatment of textile fibers, in particular proteinaceous fibers, is more particularly concerned and, quite especially, that of wool in the broader meaning of the term (sheep's wool, goat's wool, lama's wool, etc.) 1 5 More precisely, the invention relates to an oxidizing treatment, in particular a non-polluting and nondestructive treatment, of a fibrous mass such as defined hereabove, for the purpose of imparting thereto special qualities such as, in the case of wool, non-felting 2 0 capability and, in the case of wool and other different fibers, non-shrinking capability or the ability to fix dyes, for example.

As more particularly concerns wool, the following should be pointed out. 2 5 Wool fiber is a fiber of animal origin that is 97% proteinaceous. Morphologically, the fiber takes the form of a cylinder, the diameter of which varies from 15 to 40 micrometers for a length of from 20 to 150 millimeters. The fiber comprises two distinct parts: the center of the 3 0 fiber, known as the cortex, and the scales that cover the cortex. The scales as a whole are designated by the term cuticle. The scale is fixed to the cortex by a cement, but only over two thirds of its length. As a result, the end part is free and can be raised depending on the state of 3 5 the fiber. This raising phenomenon occurs when the degree of moisture of the fiber varies and the fiber is in movement, which enables it to encounter other fibers. As 2 the scales are then parted from the cortex, there occurs an interlocking phenomenon, which' becomes irreversible owing to the closing of the scales. This phenomenon is commonly referred to as 'felting'.

Felting is a major drawback as regards the upkeep of the wool. Indeed, as explained earlier, felting is linked to the movement of the fibers and their water content. That is why a woolen article has to be washed with the greatest care. It is particularly advisable to wash it by 10 hand and to dry it flat, which is a considerable constraint and, to a certain extent, restricts the development of woolen articles that require frequent washing, such as garments.

There has thus very long been a need for treatments 15 making it possible, at least to a large extent, to prevent the felting of wool when it is washed and, more recently, with the widespread use of washing machines, to machine wash it.

There is also a need for increasingly efficient 2 0 treatments for other applications, in particular for dyeing wool.

The scale is an important part of the wool since it is the site of numerous chemical reactions that occur in wool treatments, i.e. dyeing, the addition of auxiliary 2 5 products (for example, bactericidal agents), waterproofing products or resins to prevent felting.

Furthermore, combed wool naturally has a shade which, depending on its quality, varies from white to brassy. Various bleaching agents are used in the wool industry, 3 0 most of these being chlorine derivatives the use of which is increasingly restricted on account of the toxicity of their wastes.

The reactivity of wool scales can be increased for the purpose of enhancing the efficiency of these 3 5 treatments, or of reducing their duration or cost. By way of example, mention may be made of two treatments widely used in the wool industry. 3 The first example relates to dyestuffs. To obtain the desired coloration, the wool has to be placed in a dye bath, which will be brought to boiling temperature so as to enable the pores of the scales to be opened, which 5 allows the dye to diffuse inside the scales, with this taking place over periods in the order of an hour. Any treatment that enables the scales to be modified will facilitate dyeing.

Furthermore, numerous treatments have been suggested with a view to making wool machine washable. The most efficient treatment enabling the "machine washable" certificate to be obtained is to coat the wool fiber with a resin, which has the effect of preventing the wool from felting. In this treatment, the wool scales have to be 1 5 oxidized in advance to make it possible for the resin to be fixed. The different processes use oxidizing agents of a chemical type, primarily chlorine based. These products give rise to pollution which will eventually cause their use to be prohibited. 2 0 That is why alternative processes for facilitating resin fixation have been studied. Some of these consist in replacing chorine by less polluting oxidizing agents, such as permanganate, persulfates or hydrogen peroxide. Other processes aim to supplant the use of resin by reducing the 2 5 thickness of the scales or to remove the scales from the fiber completely. These processes also necessitate pre-treatment 9f the fiber by oxidation, which is followed by a treatment using a protease, for the purpose of detaching or completely destroying the scales. 3 0 The latter process makes it possible to obtain a smooth fiber that is not only non-felting but is also finer than the natural fiber or the fiber treated using the other processes, which is a commercial advantage.

It now appears to be established that a pre- 3 5 treatment, in particular by oxidizing, prior to a possible treatment by a protease, is qualitatively and economically necessary to obtain a fiber of good quality, ready to 4 receive a subsequent treatment, in particular to make it machine washable and/or to dye it in compliance with present requirements.

Now, as explained earlier, currently proposed 5 oxidizing treatments, including those that do not use chlorinated compounds, cause pollution.

According to the present invention it was hit upon the idea of making use of ozone to carry out the oxidizing treatment.

On several occasions in the past, it has been suggested using ozone to make animal fibers, such as, in particular, wool, non-shrinkable.

Thus patent US-A-4,189,303 discloses a process for making proteinaceous animal fiber based materials shrinkproof, which process consists in placing these materials in contact, for approximately 2 to 6 minutes, with an aqueous solution of ozone containing approximately *" 1 to 20 mg/1 of ozone, at a neutral pH and at a temperature of approximately 20 to 30°C. 2 0 The prior art description of patent US-A-4,189 , 303 summarizes and comments on three prior patents, namely patents GB-A-242,027, US-A-3,149,906 and US-A-3,404,942.

Patent GB-A-242,027 suggests impregnating the wool for several minutes with a 5% ammonia solution, to extract 2 5 the excess liquid therefrom and to expose it, in a humid condition, to air containing ozone in a concentration of 1 per 1000.

According to patent US-A-3,149,906, a stream composed of ozone and steam is blown through the textile to be 3 0 treated. The ozone content of the stream is approximately to 50 mg/1. The treatment is carried out at a temperature of approximately 60 to 95°C for 1 to 10 minutes.

According to patent US-A-3,404,942, a humid 3 5 proteinaceous fabric is heated on one side at a temperature of 80 to 17 0°C, while a gas stream containing ozone flows past on the opposite side.

The article entitled: Textile Research Journal, vol. 35(7), 1965, pages 638 - 647, describes the use of an ozone/oxygen gas mixture, among others, for treating moist wool fabrics at ambient temperature. There is nothing in 5 this document making it possible to conceive how the treatment that it describes, carried out on an laboratory scale, could be transposed onto an industrial scale for efficiently treating large-sized fibrous masses.

None of these treatments appears to have been 10 industrially exploited to obtain non-felting wool, and even less a machine washable wool, probably by reason of disappointing results that led the researchers to explore other channels than that of treatment with ozone, including for carrying out a pre-treatment of the scales 15 of the wool fiber.

It has now been found to be possible, in order to obtain a wool fiber of good quality, ready to receive a subsequent treatment, to carry out a pre-treatment in which polluting oxidizing agents used hitherto are 2 0 replaced by an oxidizing mixture containing a defined proportion of ozone under determined conditions.

According to one of its aspects, the invention relates to a process for oxidizing a fibrous mass in order to modify the surface of the fibers that compose it, which 2 5 process essentially comprises: a) transforming said fibrous mass into a fibrous mass containing 12.5 to 60% (g/g) of water and having a structure such that a gas can pass through it regularly and completely ; and 3 0 b) passing through said mass, for 5 to 20 minutes at ambient temperature, a gaseous mixture containing from 2 0 to 150 g of ozone per m3, which is injected" continuously through said mass as it travels on a carrier system, while being directed alternately onto the two faces of said 3 5 mass.

The expression "to modify the surface of the fibers that compose it" is to be taken here as meaning that the 6 treatment is essentially restricted to this surface and does not affect the central part of the fibers.

The modification in question is intended, in particular, to permit or facilitate subsequent treatments 5 such as, in particular, dyeing or enzyme treatment. This modification can also, in certain cases, directly impart to the fibrous mass a special quality, for example non-felting capability (non-shrinking) of the wool in the presence of water when it is not subjected to a high temperature and/or strong agitation, or bleaching.

By varying the different parameters of the process according to the invention (in particular water content, duration of the treatment and ozone concentration in the gaseous mixture), it is possible to modify a given type of 1 5 fibers to obtain the desired reactivity or, respectively, the particular quality desired. The corresponding parameters can be defined by preliminary tests.

The expression "a structure such that a gas can pass through it regularly and completely" is to be taken here 2 0 as meaning a structure such that the gas that passes through it is in contact with all the fibers and over their entire surface. A "web" of fibers generally corresponds to this definition.

"Ambient temperature" is to be taken as meaning a 2 5 temperature in the order of 15 to 30°C.

The gaseous mixture used can be any mixture containing from 20 to 150 g of ozone per m3, in the presence of one or more other gases that do not unfavorably affect the fibers, in particular their central 3 0 part. Generally, this mixture is composed of ozone in a mixture with oxygen or air, preferably with oxygen.

The process for oxidizing a fibrous mass according to the invention is implemented continuously. More precisely, the gaseous mixture containing ozone is injected 3 5 continuously through the fibrous mass of step a) as it travels on a carrier system, in particular a porous belt 7 or perforated cylinders, while being directed alternately onto the two faces of the fibrous mass.

According to one preferred form of embodiment, the fibrous mass takes the form of a continuous web, of 5 constant thickness over its entire width and length.

As the discharge of waste from large quantities of ozone into the atmosphere has polluting effects, in a particularly preferred form of embodiment, the process according to the invention is implemented in a sealed 1 0 enclosure and the ozone that is not consumed by the oxidation reaction of the fibrous mass is destroyed before the other gases in the mixture are discharged.

Different types of reactor that can be used in this particularly preferred form of embodiment of the process 1 5 according to the invention are described in the international patent application (PCT) filed in parallel in the name of the present Applicant and entitled "Reactor for treating a solid material with a noxious gas or gaseous mixture and plant including same". 2 0 Hereinafter is described the advantageous operating principle of a sealed reactor for treating a fibrous mass with a gaseous mixture containing ozone according to the invention.

The exchange between the gaseous mixture and the 2 5 fibrous mass takes place in this case by passing the gas through the mass in movement. The principles of counterflow and multiple effect are applied, which makes it possible to reduce the ozone concentration in the gaseous mixture and thus reduce its concentration in the 3 0 leakage at the entry to the reactor.

To do so, the gaseous mixture is introduced at the exit of the fibrous mass and its ozone concentration is depleted by passing it through treatment cells. Thus, the ozone concentration decreases in each cell and tends to 3 5 reach zero at the entry to the reactor.

For example, the reaction enclosure is divided into cells the tightness of which is obtained by means of 8 rollers. The gaseous mixture^is introduced at the exit of the fibrous mass, passes through- the fibrous mass in movement and then enters the following cell in the reverse direction. The gaseous mixture, the ozone of which is 5 depleted, is extracted at the entry of the fibrous mass.

To prevent the fibrous mass from being entrained by the gaseous stream, it is held between two porous conveyor belts (an upper conveyor and a lower conveyor, respectively). These two porous belts imprisoning the 10 fibrous mass move on a porous support, creating a pressure drop that facilitates the homogenous diffusion of the gaseous mixture through the fibrous mass.

According to one variant based on the same principle, in the reactor, the cells are replaced by stages ensuring 15 that the fibrous mass is turned over. An input and output lock system can be purged under the control of a probe which reacts to the presence of ozone at a threshold exceeding one ppm.

The schematic diagrams of reactors that can be used 20 advantageously to implement the process of oxidizing with a gaseous mixture containing ozone according to the invention are given in annexed Figs. 2 and 3, which will be described later.

The process according to the invention is 2 5 particularly applicable to the oxidation of wool, as illustrated in Examples 1 to 12 described in the experimental part that follows, and by the comparison of annexed Figs. 8 to 13.

Example 1 shows that the wool that undergoes the 3 0 process of oxidation with ozone according to the invention has a sensitivity to enzyme hydrolysis comparable with that of wool treated with chlorine.

Insofar, in particular, as the ozone not consumed by oxidation can easily be re-transformed into oxygen by 3 5 simple heat treatment, the process according to the invention is advantageously capable of replacing existing 9 oxidizing treatments that pollute, in particular treatments using chlorine or its compounds.

In addition, the oxygen-laden effluent gaseous mixture can be recycled after simply passing through an 5 ozone generator.

Example 2 shows that the efficiency of the subsequent treatment with the proteases can be modulated by acting on the relative moisture content of the fibrous mass of wool at the time of the ozone treatment.

Example 3 shows that the ozone treatment is capable of reducing the average diameter of the wool fibers, that is to say of enhancing their fineness while, at the same time, imparting thereto, after enzyme hydrolysis, sufficient non-felting capability to obtain the "machine washable" label without resorting to applying resin.

Example 4 shows that, for the same duration of treatment, the fineness of the fibers increases and the felting tendency decreases when the ozone concentration in the gaseous mixture increases. 2 0 Example 5 shows that the ozone treatment is capable of enhancing, on its own, the whiteness of the wool.

Example 6 shows that pre-treatment with ozone is at least as efficient as a chlorine treatment for sensitizing the wool to the application of a resin. The process 2 5 according to the invention is thus very advantageously applicable to producing machine washable wool through the application of a resin.

Example 7 shows that the ozone treatment followed by enzyme hydrolysis meets the most severe requirements as 3 0 to obtaining a considerable non-felting capability.

Examples 8 to 12 which were implemented in a pilot plant, the reactor chamber of which was 1.5 m long by 3 0 cm wide, confirm the results obtained in the other examples as to fineness and non-felting capability. 3 5 Description of the figures.

Fig. 1 is the schematic diagram of the chain of ozone treatment used in examples 1 to.5 and 7 that follow. 1 0 Oxygen is fed into a "thermostatically controlled ozone generator by water at 10°C. The ozone/oxygen mixture produced is sent to the bottom of a closed reactor provided with a grid on which are disposed, in the form of 5 a web, the wool fibers to be treated. The gaseous mixture passes through this web from bottom to top and escapes in the direction of a valve that limits the flow to 1 1/min. towards the ozone detector, within the framework of ozone consumption measurement in the reactor. The total flow of 1 0 gaseous mixture leaving the reactor is sent to a thermal ozone destroyer. The gas at the output from the destroyer is oxygen which can either be released to atmosphere or recycled to the ozone generator.

Annexed Fig. 2 diagrammatically represents a reactor 1 5 for the oxidizing treatment of the wool washed by a mixture of oxygen (or air) and ozone, as well as its environment in the case of obtaining machine washable wool .

The wool is transported into the reactor by a 2 0 conveyor band and enters the sealing chamber and then passes through the rollers of a roller press that ensures tightness with the oxidizing chamber. Inside the oxidizing chamber are two drums of perforated sheet metal rotating in opposite directions. The gaseous mixture is introduced 2 5 into the oxidation chamber and extracted by an extractor the admission of which is located inside the drums. There is thus created a depression which has the effect of forcing the gaseous mixture through the layer of wool while pressing the latter against the drums. The fact that 3 0 there are two drums makes it possible to increase the contact time. Tightness at the exit from the reactor can be obtained in the same way as at its entry. According to a variant shown on the diagram, the wool can be output by means of a system that allows the wool to drop into a 3 5 treatment bath, for example, using a protease, tightness being ensured by the bath barrier located in the conduit through which the wool drops. 11 The sealing chamber is"connected to a blower which enables an overpressure to be created in this chamber, in relation to the pressure in the oxidation chamber.

The gases escaping both from the oxidation chamber 5 and from the sealing chamber are sent to a thermal ozone destroyer.

Fig. 3 annexed shows a simplified variant of the reactor of Fig. 2 and its environment. According to this variant, the system of drums is replaced by belts with 1 0 porous conveyor bands.

The reactors of Figs. 2 and 3 ensure the protection of the environment as follows.

The gaseous mixture that has passed through the wool is discharged into the atmosphere after passing through a thermal ozone destroyer.

The ozone concentration of the air present in the sealing chamber is measured continuously. When it reaches a limit value, air is blown into this chamber so that the ozone is sent to the ozone destroyer. 2 0 Annexed Fig. 4 shows variations in absorbance at 280 nm of the supernatent of the enzyme treatment according to Example 1 as a function of the duration of hydrolysis in minutes, for a wool fiber treated with chlorine, a fiber treated with ozone and a raw fiber, 2 5 respectively.

Annexed Fig. 5 shows the variations in absorbance at 2 80 nm of, the supernatent of the enzyme treatment according to Example 2 for a wool fiber treated with ozone at a relative humidity levels of 50% and 12,5%, 3 0 respectively.

Figure 6 diagrammatically represents a continuous chain of treatment of the washed wool to make it machine washable, by enzyme hydrolysis after oxidation by ozone according to the invention. 3 5 This chain essentially comprises: - a feeding station; - an oxidizing reactor; 1 2 - finishing treatment station.

The feeding station is connected to a drum type stretching means which transforms the washed wool that is in the form of a wad into a web of suitable thickness. 5 The reactor, diagrammatically represented in Fig. 6, can be, in particular, of the type of Fig. 2 or, preferably, of Fig. 3.

The wool thus oxidized undergoes enzyme treatment and then, after rinsing, it is dried, carded, combed and 10 placed on reels.

Annexed Fig. 7 diagrammatically represents a chain of treatment of the combed wool to make it machine washable, by enzyme hydrolysis after oxidation using ozone according to the invention. 1 5 The principle of this chain of treatment is the same as in the case of Fig. 6, except that the feeding station includes a means enabling the ribbons to pass into the stretching system the function of which is to laminate the web of ribbons so as to feed the reactor with a thin web. 2 0 It is possible to humidify the ribbons before they enter the stretching means.

The chains of treatment of Figs. 6 and 7, which are described to clarify matters with regard to the treatment of the wool to make it machine washable, can easily be 2 5 adapted to other fibers and to other "finishing" treatments after ozone treatment, such as, for example, dyeing, by ,replacing the hydrolysis bath by a dye bath.

Fig. 8 is a 2000-fold enlarged photograph of a non-treated raw sheep's wool fiber. 3 0 Fig. 9 is a 2000-fold enlarged photograph of a raw sheep's wool fiber treated with GC 897 subtilisins at 2 00 Hl/1 .

Fig. 10 is a 2000-fold enlarged photograph of a sheep's wool fiber treated for 15 minutes with a stream of 3 5 2 1/min. of oxygen containing 100 g of ozone/m3.

Fig. 11 is a 2000-fold enlarged photograph of a sheep's wool fiber treated for 15 minutes with a stream of 1 3 2 1/min. of oxygen containing 100 g of ozone/m3 and then with the enzyme GC 897 at 200 fil/1. ■ Fig. 12 is a 2000-fold enlarged photograph of a sheep's wool fiber treated with chlorine at 2%. 5 Fig. 13 is a 2000-fold enlarged photograph of a sheep's wool fiber treated with chlorine at 2% and then with the enzyme GC 897 at 200 (xl/1.

No significant difference between the photographs of Figs. 8 and 9 is observable. This result shows the 1 0 inefficiency of an enzyme treatment alone using the subtilisins of GC 897 (200 |ll of GC 897, 1 liter of borate buffer solution, pH 9.5 / 0.25M / 55°C / 5 min.).

The photographs of Figs. 10 and 12 show that the treatments with ozone (100 g/m3, 2 1/min., 15 min.) and by 15 chlorination with 2% of chlorine, respectively, erode the surfaces of the fibers the edges of the cuticles of which become markedly less salient.

The photograph of Fig. 13 shows that the chlorination treatment with 2% of chlorine followed by enzyme 2 0 hydrolysis (GC 897 at 200 jxl/l, 1 liter of borate buffer solution, pH 9.5 / 0.25M / 55°C / 5 min.) is partially destructive: fragments of fiber begin to be detached from the cortex.

The photograph of Fig. 11 illustrates the average 2 5 type of fiber obtained with an ozone treatment according to the invention (100 g/m3, 2 1/min., 15 min.), followed by enzyme hydrolysis (GC 897 200 li.1/1, 1 liter of borate buffer solution, pH 9.5 / 0.25 M / 55°C / 5 min.). The fiber obtained is perfectly smooth. It has neither scales 3 0 nor signs of deterioration.

Experimental part EXAMPLE 1: Enhancement of the sensitivity of the wool to enzyme 3 5 attack 14 This example illustrates the necessity of pre-treating the fibers by oxidation to-make them sensitive to enzyme attack.

The enzyme attack is carried out on three lots of 5 fibers obtained as follows: 1. Fibers treated with chlorine: 300 g of combed, carded sheep's wool fibers are introduced into 6 liters of acetate buffer, 0.1M / pH 4, and incubated for 5 minutes at 20°C. 4% v/v of ® Basolant DC (chlorocyanurate with 62-64% of active chlorine), marketed by the BASF company, are added, and then the preparation is incubated for 45 minutes at 2 0°C. The free radicals formed are neutralized by reduction by means of 0.3% (w/v) sodium metabisulfite at 20°C for 15 15 minutes. The fiber sample is rinsed with distilled water, manually dewatered and dried for 24 hours at ambient temperature. 2. Fibers treated with ozone The ozone is generated by an Ozat-IA™ ozone generator 2 0 made by the Ozonia company, from over 90% pure oxygen. The rated production of the apparatus is approximately 80 g of 03/h, i.e. a production rate of 6% (g/g) . The precise concentration of the ozone in the oxygen is measured by U.V. photometry at 254 nm, by means of a BMT 963 on-line 2 5 analyzer made by the Ozonia company. .05 ± 0.05 g of dry sheep's wool are immersed into 1 liter of, distilled water, possibly containing hydrogen peroxide and/or sodium hydroxide. After dewatering, the fibers are placed on the grid of a reactor such as the one 3 0 shown in the schematic diagram of annexed Fig. 1.

The gaseous mixture based on oxygen with 100 g/m3 of ozone passes through this grid for 15 minutes. 3. Raw fibers (sheep's wool) Enzyme attack of fibers 1., 2. and 3. is carried out 3 5 according to a protocol suggested by the work of Peters D.E., Bradbury J.H., Material digest by trypsin from fibres and cortical cells, Aust. J. Biol. Sci. 2J5., 1225- 1 5 1234 (1972). 1.05 ± 0.05 g "of dry fibers 1., 2. or 3 . , respectively, (relative humidity: 12.5%) are introduced into 100 ml of borate buffer solution, 0.25M / pH 9.0, at 60°C. After 5 minutes' pre-incubation, 140 jll of BACTOSOL 5 WO (CLARIAN®, Ref. 2900098) and 10 y,l of GC 897 (GENECOR®) are introduced into the reaction mixture. At different time intervals, 2 ml of reaction supernatent are sampled and introduced into a hemolysis tube containing 0.5 ml of 0.1M HC1 to halt the reaction. The contents of the tube 10 are filtered (AIT CHROMATO cellulose acetate filter, diameter : 13 mm, porosity : 0.22 |um) and the absorbance of the filtrate is measured at 280 nm by means of a PERKIN ELMER LAMBDA spectrophotometer.

Absorbance at 280 nm is a function of the quantity of 15 peptides salted out by the wool during enzyme hydrolysis. The higher it is, the more sensitive the wool is to enzyme hydrolysis.

The results obtained with the three samples of fibers undergoing this hydrolysis are grouped together in Table I 2 0 below.

TABLE I Absorbance of the supernatent at 280 nm Time (minutes) Chlorinated fibers Ozonized fibers Raw fibers 0 0.063 0.041 0 1/6 - 0.218 0.18 0 1/3 0.289 0.25 0.005 1/2 0.338 0.008 2/3 0.379 0.392 0.01 /6 0.416 _ 0.015 1 0.452 0.446 0.019 2 0.569 0.526 0.042 3 0.649 0.588 0.0745 4 0.726 0.639 0.096 0.781 0.684 0.121 1 6 These results are represented in the form of a graph in Fig. 4, which shows, for each sample of fibers, the changes in the absorbance of the supernatent at 280 nm as 5 a function of the duration of the hydrolysis.

This example highlights the fact that the ozonized wool has a sensitivity to enzyme hydrolysis comparable with that of chlorinated wool, whereas the wool that has not undergone an oxidizing pre-treatment has practically 10 no sensitivity.

EXAMPLE 2 : Effect of the moisture content on the efficiency of the treatment for sensitizing the wool fibers to enzyme attack The relative humidity of two samples of sheep's wool fibers is fixed at 12.5 and 50%, respectively. These samples are introduced into the ozonization chamber used in Example 1 and subjected to the same ozonization treatment (100 g of 03/m3, 2 1/min., 15 minutes) . The 2 0 sensitivity to enzyme attack of each of the samples is determined according to the technique described in Example 1.

The results obtained are grouped together in Table II below. 3 5 17 TABLE II Supernatent absorber at 2 80 nm Time (minutes) Ozonized fibers (r.h. = 50%) Ozonized fibers (r.h. = 12.50%) 0 0.041 0 1/6 00 O 0 1/3 0.25 0 1/2 _ 0.004 2/3 0.392 0 /6 _ 0.01 1 0.446 0.014 2 0.526 3 0.588 0.04 4 0.639 0.086 0.684 0. 092 mJ These results are presented in the form of a graph in 5 Fig. 5, which shows, for each sample, the changes in the absorbance of the supernatent at 2 80 nm as a function of the duration of hydrolysis.

This example highlights the fact that the efficiency of the treatment of sensitization to proteases depends on 10 the relative moisture content of the fibers at the time of oxidizing pre-treatment with ozone. It shows that it is preferable to work with a relative humidity of 50%, rather than with 12.5%.

EXAMPLE 3 : 1 5 The effect of ozone on the diameter of the fibers and their felting capability Within the framework of the research that led to the invention, an analytical method was developed that makes it possible to evaluate the enhancement of the reactivity 2 0 of the wool. This method consists in subjecting the wool, after its oxidizing pre-treatment with ozone, to 1 8 proteolytic hydrolysis and in then measuring its fineness and its felting capability.

A sample of 10.00 ± 0.05 g of carded sheep's wool with a water content of 5 0% is placed on the grid of the 5 reactor used in Example 1. A stream of gaseous mixture (2 1/min.), composed of oxygen containing 30 g of ozone/m3, passes through the wool. The experiment is conducted 4 times with variable durations of ozone pre-treatment (0 to 20 min.).

In a second step, all the samples are subjected to enzyme treatment (GC 897 200 \xl/l, in 1 liter of borate buffer solution, pH 9.0 / 0.25M / 55°C). The felting capability and the changes in the fineness (average diameter) of the fibers of each sample are determined, 1 5 respectively, according to the IWTO 20-69 and IWTO 12-95 standards.

The results obtained are grouped together in Tableau III below.

TABLE III Ozone consumption (mq/q of wool) Fineness (|Xm) (IWTO 12-95) Density of the ball (g/cm3) (IWTO 20-69) Control 0 21.4 0.192 minutes 4.2 21.4 0.125 14 minutes 12 .8 0.053 minutes 26 .3 0.053 This table clearly shows that the ozone treatment makes it possible to reduce the average diameter of the fibers (increase in fineness) and their felting capability 2 5 (density of the ball) .

EXAMPLE 4 : The experiments of Example 3 are repeated but using, for the ozone treatment, a gaseous mixture containing 100 g of ozone/m3. 1 9 The results obtained are gathered together in Table IV below.

TABLE IV Ozone consumption (mg/g of wool) Fineness (J-tm) (IWTO 12-95) Density of the ball (g/cm3) (IWTO 20-69) Control 0 21.4 0.192 minutes 24 .8 0.057 14 minutes 46 18.4 not measurable minutes 60 17 .5 not measurable This table shows that the amplitude of the reduction of the average diameter of the fibers and of the felting capability increases, for a given duration of ozone treatment, as a function of the concentration of the ozone 10 in the gaseous mixture.

EXAMPLE 5 : Bleaching the wool with the ozone treatment Samples of 10.00 + 0.05 g of wool are treated for 10 minutes by means of a mixture of oxygen and ozone having 1 5 30 and 100 g of ozone/m3, respectively, the flow of the mixture being 2 1/minute.

These samples are then treated, or otherwise, with proteases (GC 897 at 200 (xl/1, in 1 liter of borate buffer solution, pH 9 / 0.25 M, 55°C) . 2 0 The whiteness of the wool treated is, in each case, measured by means of a MICROCOLOR reflectometer. It is expressed according to the IWTO 3 5 method and the degree of whiteness is represented by the letter W. The lower the W value, the whiter the wool. 2 5 The results obtained are gathered together in Table V below.

TABLE V Test W (whiteness) Raw fibers El 49.4 Ozone fibers 30 E2 44.4 Ozone fibers 100 E3 44.7 Ozone fibers 30 + enzymes E4 44.5 Ozone fibers 100 + enzymes E5 42.6 This table makes it possible to note that the 5 whiteness of the wool fibers is enhanced by the ozone treatments.

The improvement is comparable in the case of tests E2 to E4, and markedly greater in that of test E5.

EXAMPLE 6 : 1 0 Sensitization of the wool fibers to the application of a resin, caused by ozone pre-treatment In this example, the samples tested receive an application by exhaustion of Hercosett® 125LX resin made by the HERCULES company. This resin is a polyamide resin 1 5 treated with cationic epichlorhydrin which is reactive vis-a-vis the fibers.

This resin is chosen as it claims the status of anti-felting finishing agent for wool in the exhaust process after chlorination. It was developed to■obtain a marked 2 0 reduction in the contribution of the resin to the halogenated organic compound content in the effluents. The samples tested are as follows: 1. - 40 g of a control material (raw fiber) in the form of a ribbon of combed sheep's wool at 20 g/m of wool fibers 2 5 with an average fineness of 21.5 |im; 2. - 40 g of a so-called "03 treated" material according to the invention in the form of 4 sections of 10 g each (treatment for 10 g of wool: 15 minutes in a flow of 2 1/min. of oxygen containing 100 g of ozone/m3) ; 2 1 3. - 75 g of a so-called "Cl2 treated" material in a ribbon of combed sheep's wool (2% chlorination).

The general conditions of application of the resin are as follows. 25 g of wool are disposed in a pot of dye of the AHIBA TURBOMAT laboratory system containing 0.5 liters of a 6 g/1 solution of Hercosett 125LX with a pH of between 7.8 and 8.2 obtained by the addition of 28% ammonia. This bath is applied to the wool at 30°C for 45 minutes. 10 The sections of ribbon are then padded (45 kg/cm) twice and then dried in hot air at 85°C for 15 minutes. Next, the resin is polymerized by exposing the sample to a temperature of 110°C for 4 minutes.

A few grams of each of the samples are carded by hand 15 after the finishing treatment and 1 g of the carded sample is made to undergo the test on reactivity of the fibers to ® the dyestuff Bleu Lanasol 3R which is an equivalent to Procion M3 blue.

This test is currently used to determine the ® 2 0 homogeneity of the applications of Hercosett 125LX to the wools that have undergone a chlorinating pre-treatment.

In this test are determined two values, L* and b*, which are colorimetric parameters that make it possible to indicate the taking efficiency of the Bleu Lanasol 3R. 2 5 They thus make it possible to measure the application efficiency of the Hercosett® 125LX resin capable of absorbing the coloration. b* corresponds to the yellow-blue chromatic component and J* to the clarity of the sample tested. 3 0 Thus, the lower the value b*, the greater the blue coloration of the sample.

Furthermore, the lower the clarity value L*, the greater the coloration intensity.

Specifically, the application of the resin to the 3 5 sample tested is all the more efficient the lower the corresponding b* and L* values. 22 The results obtained are gathered together in Table VI below.

TABLE VI Sample L* b* Raw fibers 75.71 -3.38 Cl2 treated fibers 60.17 -11.79 03 treated fibers 54.62 -16.61 Raw fibers -Hercosett 64.35 13 .28 Cl2 treated fibers - Hercosett 36.75 -25.53 03 treated fibers -Hercosett 32 .56 -27 .32 This table shows that the blue tint is darkest in the case of the samples oxidized with chlorine or ozone.

The depth of tone is yet further accentuated in the case of the wools treated with Cl2 or 03 and the resin.

The bluest sample is the one that is finished with Hercosett 125LX after pre-treatment with ozone.

To conclude, the wool oxidized according to the ozone pre-treatment process is also affine in the case of resins ® such as Hercosett 125LX, and even more affine than a wool 15 oxidized by chlorination.

EXAMPLE 7 : Producing "machine washable" quality for a knit fabric obtained from fibers of wool treated with ozone and then subjected to enzvme hvdrolvsis 2 0 Within the framework of the European standards, the most drastic maximum limits of shrinkage measured according to the IWS TM31 test are applied to articles of textile footwear. In this case, shrinkage of surface area after one 7A cycle followed by 5 5A cycles must not exceed 2 5 8%. This shrinkage value thus corresponds to a limit that must not be exceeded. 23 Two samples of knit fabric of 100 cm2 were tested. The first was carried out with non treated sheep's wool fibers. The second was carried out with sheep's wool fibers treated with ozone (lOOg of 03/m3, 2 1/min., 15 5 minutes) and then with enzyme GC 897 (200 jil/1 of borate buffer solution, 0.25M / pH 9.1 / 55°C / 1 liter).

The dimensional changes in the samples were measured after one 7A washing cycle followed by 5 5A washing cycles and drying flat. The results are expressed by calculating 1 0 the percentage shrinkage of area of the woolen knit fabric in question.

The sample of untreated fibers presents a total shrinkage at the end of the test of 80%. Under the same conditions, the sample of fibers treated with ozone and 15 subjected to enzyme hydrolysis presented a shrinkage of only 4%. This result is perfectly comparable with that obtained in the case of chlorinated fibers. The fibers treated according to the present invention are thus of "machine washable" quality. Articles made from these 2 0 fibers can lay claim to the WOOLMARK "machine wash" label.

EXAMPLE 8 : Three ribbons of combed wool with a diameter of 21.7 nm and a metric weight of 48 g are immersed into water and then dewatered so as to reduce their moisture to 2 5 40%. These ribbons pass through a machine that enables them to be stretched 5.6 times. The web of wool obtained passes through the reactor at a speed of 0.3 m/min., which corresponds to a contact time of 5 minutes.

The reactor is fed with a gaseous mixture of oxygen 3 0 and ozone, the ozone concentration of which is 112 g/m3 and the flow rate of which is 3.5 m3/h.

The wool at the output from reactor is dried and is then subjected to the aforementioned enzyme treatment. The results obtained are gathered together in Table VII below. 2 4 TABLE VII Sample Production in kg/h Fineness (Urn) (IWTO 12-95) Density of the ball (g/cm3) (IWTO 20-69) Surface shrinkage (IWS TM 31) Combed wool 21.7 0.183 60% Ozonized wool 0.4 21.4 Not measurable Not measured Proteolyzed ozonized wool .3 Not measurable 1.9% EXAMPLE 9 : Three ribbons of combed wool of 22.1 |um in diameter and with a metric weight of 55 g pass through a machine enabling them to be stretched 1.22 times. The web of wool obtained is immersed into water and then dewatered to a moisture content of 40%. It passes through the reactor at a speed of 0.15 m/min., which corresponds to a contact time of 10 minutes.

The reactor is fed with a gaseous mixture of oxygen and ozone,, the ozone concentration of which is 112 g/m3 and the flow rate of which is 1.75 m3/h. 1 5 The wool at the output from the reactor is dried and then subjected to the aforementioned enzyme treatment. The results obtained are gathered together in Table VIII below.

TABLE VIII Sample Production in kg/h Fineness (|lm) (IWTO 12-95) Density of the ball (g/cm3) (IWTO 20-69) Combed wool 22.1 0.192 Proteolyzed ozonized wool 0.95 21.5 Not measurable EXAMPLE 10 : Three ribbons of combed wool of 22.1 jxm in diameter and with a metric weight of 55 g pass through a machine 5 enabling them to be stretched 1.22 times. The web of wool obtained is immersed into water and then dewatered to a moisture content of 40%. It passes through the reactor at a speed of 0.15 m/min., which corresponds to a contact time of 10 minutes. 1 0 The reactor is fed with a gaseous mixture of oxygen and ozone, the ozone concentration of which is 112 g/m3 and the flow rate of which is 3.5 m3/h.

The wool at the output from the reactor is dried and then subjected to the aforementioned enzyme treatment. The 15 results obtained are gathered together in Table IX below.

TABLE IX Sample Production in kg/h Fineness (Urn) (IWTO 12-95) Density of the ball (g/cm3) (IWTO 20-69) Combed wool 22 .1 0.192 Proteolyzed ozonized wool 0.95 21.5 Not measurable 2 0 EXAMPLE 11: Three, ribbons of combed wool of 22.1 Jim in diameter and with a metric weight of 55 g pass through a machine enabling them to be stretched 1.22 times. The web of wool obtained is immersed into water and then dewatered to a 2 5 moisture content of 40%. It passes through the reactor at a speed of 0.3 m/min., which corresponds to a contact time of 5 minutes.

The reactor is fed with a gaseous mixture of oxygen and ozone, the ozone concentration of which is 112 g/m3 3 0 and the flow rate of which is 3.5 m3/h. 26 The wool at the output from the reactor is dried and then subjected to the aforementioned enzyme treatment. The results obtained are gathered together in Table X below.

TABLE X Sample Production in kg/h Fineness ([Xm) (IWTO 12-95) Density of the ball (g/cm3) (IWTO 20-69) Combed wool 22.1 0.192 Proteolyzed ozonized wool 1.9 21.6 Not measurable EXAMPLE 12: Three ribbons of combed wool of 22.1 |0iri in diameter 1 0 and with a metric weight of 55 g pass through a machine enabling them to be stretched 1.22 times. The web of wool obtained is immersed into water and then dewatered to a moisture content of 40%. It passes through the reactor at a speed of 0.15 m/min., which corresponds to a contact 15 time of 10 minutes.

The reactor is fed with a gaseous mixture of oxygen and ozone, the ozone concentration of which is 112 g/m3 and the flow rate of which is 1.05 m3/h.

The wool at the output from the reactor is dried and 2 0 then subjected to the aforementioned enzyme treatment. The results obtained are gathered together in .Table XI below.

TABLE XI Sample Production in kg/h Fineness (Mm) (IWTO 12-95) Density of the ball (g/cm3) (IWTO 20-69) Combed wool 22 .1 0.192 Proteolyzed ozonized wool 0.9 21.7 Not measurable 27

Claims (25)

1. Process for oxidizing a fibrous mass in order to modify the surface of the fibers that compose it, which process essentially comprizes : 5 a) transforming said fibrous mass into a fibrous mass containing 12.5 to 60% (g/g) of water and having a structure such that a gas can pass through it regularly and completely ; and b) passing through said mass, for 5 to 20 minutes at 10 ambient temperature, a gaseous mixture containing from 20 to 150 g of ozone per m3, which is injected continuously through said mass as it travels on a carrier system, while being directed alternately onto the two faces of said mass . 15

2. Process according to claim 1, characterized in that the fibrous mass is a mass of textile fibers,

3. Process according to claim 2, wherein the textile fibers are proteinaceous fibers.

4. Process according to claim 3, wherein the proteinaceous fibers are wool fibers.

5. Process according to any one of claims 1 to 4, characterized in that the gaseous mixture is constituted by ozone in a mixture with oxygen or air.

6. Process according to claim 5, wherein the gaseous mixture is constituted by ozone in a mixture of oxygen.

7. Process according to any one of claims 1 to 6, characterized in that the carrier system is constituted by a belt or by perforated cylinders.

8. Process according to any one of claims 1 to 7, characterized in that it is implemented in a sealed enclosure and in that the ozone not consumed by the oxidation reaction of the fibrous mass is destroyed before the other gases in the mixture are discharged. intellectual property office of n.z. - 9 DEC 2003 28

9. Process according to any one of claims 1 to 8 ,f characterized in that the fibrous mass travels in counterflow to the gaseous mixture.

10. Reactor for implementing the process according to any one of claims 1 to 9, characterized in that it functions according to the principles of counterflow and multiple effect.

11. Process for reducing the mean diameter of the wool fibers, characterized 'in that it includes a step of oxidation of said fibers according to the process of any one of claims 1 to 9, followed by a...step of treatment with proteolytic enzymes.

12. Process for polishing the wool fibers without damage to their cortex, characterized in that it includes a step of oxidation of said fibers according to the process of any one of claims 1 to 9, followed by a step of treatment with proteolytic enzymes.

13. Process for increasing the whiteness of the wool fibers, characterized in that it includes a step of oxidation of said fibers according to the process of any one of claims 1 to 9, possibly followed by a step of treatment with proteolytic enzymes.

14. Process for increasing the reactivity of the wool fibers to the application of a resin or of a dye, characterized in that it includes a step of oxidation of said fibers according to the process of any one of claims 1 to 9.

15. Process for obtaining wool fibers of the "machine washable? type, characterized in that it includes a step of oxidation of said fibers according to the process of any one of claims 1 to 9, followed by a step of treatment by proteolytic enzymes. .

16. Chain of treatment for implementing the process according to any one of claims 11 to 13 and 15 or for the preparation of fibers and a subsequent treatment, characterized in that it essentially includes a fiber intellectual property office of n.z. - 9 DEC 2003 RECtlVtU 29 feeding station, a stretching means, a reactor for implementing the oxidation process according to any one of claims 1 to $, a system for subsequent treatment, a rinsing device, a drying device and a device for packaging the fibers*;

17. Chain of treatment according to claim 16, wherein the device for packaging the fibers is a device for placing them on reels.;

18. A process according to claim 1 substantially as herein described with reference to any example thereof.;

19. A reactor according to claim 10 substantially as herein described with reference to any example thereof.;

20. A process according to claim 11 substantially as herein described with reference to any example thereof.;

21. A process according to claim 12 substantially as herein described with reference to any example thereof.;

22. A process according to claim 13 substantially as herein described with reference to any example thereof.;

23. A process according to claim 14 substantially as herein described with reference to any example thereof.;

24. A process according to claim 15 substantially as herein described with reference to any example thereof.;

25. A chain of treatment according to claim 16 substantially as herein described with reference to any example thereof.;I '■WW* END OF CLAIMS I " 0F Nz I - 9 dec 2003 | RECEIVED