WO2006058990A1 - Continuous textile converting method and installation therefor - Google Patents

Abstract

The invention concerns a method for continuously converting textile materials by passing same in a microwave field and contacting same with a surface capable of being heated. The inventive method consists, after depositing treating agents on said textile material, in: continuously passing the textile material and its deposited treating agents inside a chamber; applying inside the chamber a microwave radiation at atmospheric pressure; contacting inside the chamber the textile material with a surface capable of being heated; extracting the steam from inside the chamber throughout retention time of the textile material in the chamber.

Description

 METHOD OF CONTINUOUS TEXTILE ENNOBLICATION AND INSTALLATION IMPLEMENTING SAID METHOD

The present invention relates to a continuous process of finishing with or without tension of textile materials by passing them in a microwave field and contact with a surface capable of being heated. The invention also relates to an installation implementing said method.

In France, the finishing sector annually consumes approximately 50 million ^m3 of water which must then be decontaminated before being discharged into the environment (EU Directive 21/271 / EEC of 21 May 1991).

In conventional dyeing processes, large amounts of treated water are used, which generates a large amount of wastewater. The costs of remediation are often exorbitant for these companies. In addition, these large volumes of water are heated for long hours resulting in high energy consumption.

Various types of textile finishing processes have been proposed which aim to reduce the amount of water required for the treatment of textile materials and / or the duration of treatments and / or the amount of energy consumed during these treatments.

Some of these processes use microwaves, because of the multiple benefits they provide:

the microwaves penetrate immediately into the textile materials and induce a very rapid heating thereof, since, unlike all the other heating methods, heating does not depend in this case on the thermal conductivity; this results in a significant time saving;

they provide uniform heating of the textile material;

they allow a control of the interactions between the textile material and the treatment reagents according to the treatment applied to the textile material, by the simple adjustment of the flow as a function of the weight of the fabric;

- the total absence of energy losses by heat radiation, which results in savings and better working conditions. The present invention aims to provide a textile finishing process to reduce water pollution at the source by limiting the consumption of water, energy and dyeing auxiliaries.

For this purpose and according to a first aspect, the invention relates to a continuous process in the continuous treatment of a textile material, comprising a step of depositing on said textile material treatment agents, characterized in that it includes the following steps:

- continuously pass the textile material and its deposit of treatment agents inside a chamber; - Apply inside the chamber microwave radiation at atmospheric pressure;

bringing into contact within the enclosure the textile material with a surface capable of being heated;

extracting the water vapor from inside the enclosure during the entire residence time of the textile material in the enclosure.

In some embodiments, the deposition step comprises a step of impregnating said textile material in a bath containing the reagents necessary for the treatment and a squeezing step until a given carry rate is obtained. The textile material is impregnated with reagents and expressed in order to obtain a transport rate of between 40 and 200%.

In other embodiments, the deposition step comprises a step of printing said textile material.

The power of the microwave radiation is a function of the weight of fabric treated and is between 0.8 and 3 kWh per kg of treated textile material. The residence time of said textile material in the enclosure being of the order of 60s to 240s. These durations can be modulated according to the quality and nature of the material.

Preferably, said heatable surface is the outer surface of a rotating cylinder. Its temperature can be brought to 210 ^° C. According to a second aspect, the subject of the invention is an installation for the continuous treatment of a textile material comprising depositing means. treatment agents on said material, characterized in that it also comprises: an enclosure having an inlet opening and an outlet opening of the material; o application means on the textile material of a microwave radiation inside the chamber; a surface capable of being heated and coming into contact with the material during the movement thereof inside the enclosure; o means for extracting the water vapor formed inside the enclosure.

The invention will now be described in detail.

The present invention relates to a textile finishing process that significantly reduces the amount of water and energy used, the duration of treatment and the discharge of effluents.

Textile finishing, which includes all the treatments that can be done to a textile to improve its appearance or its properties, is divided into three parts: pre-treatments, dyeing and post-treatments .

The pre-treatments are intended to prepare the textiles to make them white, able to be dyed or to give them special properties.

The process according to the invention also makes it possible to carry out various post-treatments such as: drying, primer, softening.

The process according to the invention can be used for the preparation, dyeing, printing and after-treatment of all natural, artificial and synthetic textile materials.

In an alternative embodiment, the textile material is, firstly, immersed according to the type of operation in a bath containing the products necessary for the chosen treatment: scouring, bleaching, dyeing, wet primer. The baths used may be those derived from dye cards with quantities adapted to very short bath ratios.

After its impregnation, the textile material is expressed in order to obtain a load factor of between 40 and 200%. Many auxiliary dyeing products, such as carriers, dispersants, unison agents, wetting agents, performance agents, antifoam, urea, have been removed from the baths through the use of microwaves.

In another embodiment, the textile material is first printed by a printing paste or by inks to form patterns.

The textile material is then introduced into an enclosure inside which microwave radiation is applied.

The microwave field is generated by one or more magnetrons of known type in order to obtain a sufficient power as a function of the quantity of textile to be treated and at the desired speed (required energy of the electromagnetic radiation between 0.8 and 3 kWh per kg of material). The duration of microwave treatments can range from 60 to 240 seconds.

The textile material is brought into contact, inside the enclosure, with a surface capable of being heated, while being exposed to microwave radiation. The textile material travels at a known speed, depending on the length of the path in the enclosure.

In a preferred embodiment, the textile material is brought into contact inside the enclosure with a heated surface at a temperature between 40 and 210 ⁰ C depending on the type of treatment of the nature of the textile to be treated. This makes it possible to obtain a synergistic effect between the action of the microwaves and the radiant heat energy of said surface, which will contribute to obtaining the desired technical effect corresponding to the treatment applied to the textile material, while limiting the duration as well as the consumption of water, energy and auxiliary dyes.

In another embodiment, the method of the invention is implemented without said surface being heated, its temperature being that ambient (between 20 and less than 40 ^° C.). This case applies in particular to the dyeing of cotton in direct dyes. In a preferred embodiment, the heatable surface is the outer surface of a rotating cylinder. The residence time of the textile material in the enclosure, which corresponds to the time of application of the microwave radiation, is between 60 and 240 s.

The method of the invention also comprises a step of extracting the water vapor formed inside the enclosure during the application of the microwave radiation. This is achieved by means of water vapor suction means such as a vacuum system.

The method may also include mixing the microwave radiation inside the enclosure to prevent stationary waves from appearing. The process is suitable for the application of both chemical treatments

(preparation and post-processing of textiles) as dyestuffs. These textiles can be in various forms: yarns, yarns, fabrics, nonwovens, felts and knits. Dyes or prints made using this process for all the usual classes of dyes and all kinds of fibers.

As regards the treatment of cellulosic fibers, it takes into account materials made of regenerated cellulose and natural cellulose.

Thus, for example, viscose, hemp, flax, jute and cotton can be processed, but also mixtures of materials such as the cotton / polyester / elastane blend.

For scouring these materials, using a bath containing a wetting agent-detergent which is resistant to basic pH and an alkaline agent in varying amounts depending on the impurity level of the material to be treated.

The bleaching of the cellulosic materials is carried out in the presence of an oxidizing agent (hydrogen peroxide), an alkaline agent (pH between 9 and 11) and a stabilizing agent for hydrogen peroxide. In order to obtain a higher degree of whiteness, it is possible to add optical brighteners to the whitening bath or to azure the material after bleaching.

The dyeing of cellulosic materials can be carried out with dyes such as direct dyes, reactive dyes. Other dyes such as sulfur dyes may be, after modification, used. The dyeing with the reactive dyes is carried out in an alkaline medium. The bath must be in a range of pH between 9 and 12. The use of a yield agent is most of the time necessary. The sulfur dyes are introduced into the impregnation bath in their soluble form. The bath contains a reducing agent to keep them in this form and an alkaline agent to have a pH of between 10 and 12.

The amount of dye introduced into the bath is a function of the desired height of the tone and the solubility limit of each of them under the operating conditions.

Treatments of synthetic fibers such as polyamides 6 and 66, natural such as wool or silk or fiber mixtures containing these materials can be carried out according to the same method.

For the degreasing of the wool, the bath may contain an alkaline agent, in order to obtain a pH of between 8.5 and 9.5 and a suitable detergent agent. Natural polyamides may require bleaching. The oxidizing bleaching bath contains an oxidizing agent such as hydrogen peroxide, an alkaline agent and a stabilizer. The reducing bleaching bath contains a reducing agent such as sodium hydrosulfite. These bleaching agents are introduced in a variable amount into the treatment bath depending on the type of polyamide treated. The dyeing of polyamides can be carried out with anionic dyes such as acid dyes, metallics 1/1 and 1/2, and reactive dyes. Dyeing is carried out in acidic medium (pH between 3 and 7). Synthetic polyamides can be dyed with cationic or disperse dyes. It is also possible thanks to the process to dye the synthetic fibers with the disperse dyes in a slightly acid medium (pH between 5.5 and 6.5). In most cases the addition of an anti-migrant agent is necessary. Post-dyeing of polyester, for example, can also be carried out by the process using an alkaline bath containing sodium hydrosulfite.

The process also relates to dyeing the mixtures. It is thus possible to treat, for example, materials made of cotton and polyester or wool and polyester or any other mixture. The method further enables the treatment of elastane-containing materials. The operating conditions to which the material is subjected do not deteriorate the properties of elastane.

Depending on the particularities of each material, auxiliary dyeing products may be added in small quantities to the various treatment baths.

The present invention will be better understood on reading the following examples which are given, without limitation, in order to better illustrate the characteristics of the textile finishing process which is the subject of the present invention.

Example 1: Unclogging of cotton

An unbleached fabric 100% cotton 120 g / m ² is impregnated at 25 ⁰ C using a bath containing: - 10 g / 1 of wetting agent such as mercerisin OR, - 150 ml / I of hydroxide 30% sodium

- 6 g / 1 of sodium carbonate.

The time of contact with the bath is the time required for good impregnation and the rate of carriage is 70%. It is then exposed to a microwave field with a radiation power of 1200 W and is brought into contact with a heated surface at 50 ⁰ C while undergoing microwave radiation. The treatment time is 180 s. The fabric is then rinsed hot, then cold.

Example 2: Dyeing cotton with reactive dyes

A 100% cotton fabric of 120 g / m ² previously bleached and bleached is impregnated at 25 ^° C. using a bath containing:

- 10 g / 1 of reactive dye of commercial name red cibacrone CR,

6 ml / l of 30% sodium hydroxide, 10 g / l of sodium carbonate,

30 g / l of sodium chloride. The carrier rate is 70%. The fabric is exposed to a microwave field with a radiation power of 1200 W and brought into contact with a heated surface at 150 ⁰ C while undergoing microwave radiation. The treatment time is 120 s. The fabric is rinsed cold, hot, then soaped and finally rinsed again.

Comparison of the COD release of a reactive dye cotton dye with a conventional Pad-Batch process:

The bath used for the pad-batch is the one recommended in the cards:

20 g / l of dye (red cibacrone CR, yellow cibacrone CR, blue cibacrone CR),

- 70 ml / 1 of sodium silicate,

- 6 ml / 1 of sodium hydroxide

- 24 hours cold storage.

The COD releases in the effluents from the pad-batch process were compared with those from a cotton dye according to the invention. The results are shown in diagram 1, in which the dark columns relate to the pad-batch process and the light columns to the process according to the invention.

Yellow Red Blue

Diagram 1

These results show that for the yellow and blue dyes, the COD discharges in the effluents of the process according to the invention are significantly reduced compared with the conventional pad-batch process. Example 3: Dyeing the polyester in disperse dyes

A 290 g / m ² 100% polyester fabric is impregnated at 50 ^° C. using a bath containing: 10 g / 1 of Foron RD-GL red-colored dispersed dye,

- 1 ml / 1 of acetic acid,

- 10 g / 1 of anti-migrant such as Solidokol K.

The carrier rate is 70%. The fabric is exposed to a microwave field with a radiation power of 1200 W and is brought into contact with the heated surface at 180 ⁰ C while undergoing microwave radiation. The treatment time is 120 s. The fabric is then rinsed, stripped, and rinsed again.

The stripping that removes the unbound dye was done in full bath or using the present invention. The results obtained are shown in Table 1.

Stripping in full bath Stripping using the method according to the invention

3 g / l of sodium hydrosulfite, 40 g / l of sodium hydrosulfite,

3 g / l of sodium hydroxide, 40 g / l of sodium hydroxide,

- Bath report 1/20, - Carry rate 60%

- Treatment time 20 min at 9O ⁰ C "Surface temperature 180 ⁰ C

- 120 s processing time

COD of the effluents before COD of the effluents after COD of the effluents before COD of the effluents after treatment of these: treatment of these: treatment of these: treatment of these:

711 mgO 2 / l 539 IDgO ₂ /! 83 IHgO ₂ /! 43 IDgO ₂ /!

Table 1

These results show a significant reduction of the COD in the effluents from the stripping according to the invention compared with stripping in full bath. Example 4: Dyeing wool with acid dyes

A 310 g / m ² 100% wool fabric, previously degreased, is impregnated at 50 ^° C. using a bath containing:

10 g / l of acid dye of commercial name floxine erio solid KL, 4% of sulfuric acid (relative to the weight of textile material).

The contact time with the bath is 5 seconds and the rate of carriage is 80%. The fabric is exposed to a microwave field of 1200 W radiation power and is contacted with an unheated surface while undergoing microwave radiation. The treatment time is 120 s. The fabric is then rinsed.

Example 5: Dyeing cotton in direct dyes

A 100% cotton fabric 120 g / m ² previously bleached and bleached is impregnated at 25 ⁰ C using a bath containing: - 40 g / 1 of direct dye commercial orange sirius 3 GDL name,

The carriage rate is 50%. The fabric is then exposed in an enclosure to a microwave field of 1200 W radiation power and is contacted with an unheated surface while undergoing microwave radiation. The treatment time is 120 s. The fabric is rinsed cold, hot, then soaped and finally rinsed again.

Example 6: Dyeing the cotton / polyester mixture r50 / 50) in reactive and dispersed dyes

A knit made of 50% cotton and 50% polyester of 200 g / m ² previously bleached and bleached is impregnated at 25 ^° C. using a bath containing:

- 15 g / 1 disperse dyes of the name Red Foron RD GL 200%

- 1 ml / 1 of acetic acid,

- 10 g / 1 solidokol K

The carrier rate is 70%. The knit is then exposed in a chamber to a microwave field with a radiation power of 1200 W and is brought into contact with a heated surface at 150 ^° C. while undergoing radiation. microwave. The treatment time is 240 s. The fabric is rinsed, stripped, rinsed.

It is then impregnated at 25 ^° C. with a bath containing:

30 g / l of reactive dye of commercial name Bleu cibacrone CR, 10 g / l of sodium carbonate,

6 g / l of sodium hydroxide,

30 g / l of sodium chloride.

The carrier rate is 70%. The knit is then exposed in a chamber to a microwave field with a radiation power of 1200W and is brought into contact with a heated surface at 150 ⁰ C while undergoing microwave radiation. The treatment time is 120 s. The fabric is rinsed, soaped and rinsed.

Example 7 Printing of Cotton with Reactive Dyes

A 100% cotton fabric of 120 g / m ² previously debunked and bleached is printed at 25 ° C using a paste containing:

- 40 g / kg of sodium alginate,

20 g / kg of sodium carbonate (Na ₂ CO 3), 2 ml / kg of sodium hydroxide (NaOH) at 36 ° Be,

25 g / kg of dye

- Water, sufficient quantity for 1 kg.

The fabric is printed using a rotating frame. The pressure exerted on the squeegee is 2 bars. The fabric is then exposed in an enclosure to a microwave field with a radiation power of 1200 W and it is brought into contact with a heated surface at 150 ^° C. while undergoing microwave radiation. The treatment time is 120 s. The fabric is rinsed cold, hot, then soaped and finally rinsed again.

According to a second aspect, the subject of the invention is an installation for the continuous treatment of a plane textile material comprising either means impregnating said material and the expressing means, or printing means, characterized in that it also comprises: an enclosure comprising an inlet opening and an outlet opening of the material; o application means on the textile material of a microwave radiation inside the chamber; a surface capable of being heated and coming into contact with the material during the movement thereof inside the enclosure; o means for extracting the water vapor formed inside the enclosure.

In one embodiment, the deposition means comprise impregnation means and means for expressing said material.

In another embodiment, the deposition means comprise printing means.

The temperature of said surface is between 20 and 21O ⁰ C. The surface may or may not be heated depending on the nature of the textile material to be treated. The heatable surface is brought into contact with the textile material which travels at a speed as a function of the length of the path in the enclosure. The residence time of the textile material in the enclosure, which corresponds to the time of application of the microwave radiation, is between 60 and 240 s.

Preferably, the heating surface is the outer surface of a rotating cylinder.

In one embodiment, the cylinder is made of non-magnetic metal and inert with respect to the chemical compounds introduced into the baths and may comprise a PTFE coating.

The entry and exit of the material is effected through slots of suitable shape in order to avoid any wave propagation to the outside.

The means for extracting the water vapor formed inside the enclosure are those known to those skilled in the art, for example a pressure-reducing system or a ventilation system. The installation according to the invention may comprise means for mixing the microwave radiation inside said enclosure.

Claims

1. Process for the continuous treatment of a textile material, comprising a step of depositing on said textile material treatment agents, characterized in that it comprises the following steps: - to continuously pass the textile material and its deposit of treatment agents inside a chamber; - Apply inside the chamber microwave radiation at atmospheric pressure; bringing into contact within the enclosure the textile material with a surface capable of being heated; extracting the water vapor from inside the enclosure during the entire residence time of the textile material in the enclosure. 2. Method according to claim 1 characterized in that the deposition step comprises a step of impregnating said textile material in a bath containing the reagents necessary for the treatment and a squeezing step until a rate is obtained. given carriage. 3. Method according to claim 2 characterized in that the textile material is impregnated with reagents and expressed in order to obtain a carrier rate of between 40 and 200%. 4. Method according to claim 1 characterized in that the deposition step comprises a step of printing said textile material. 5. Method according to any one of claims 1 to 4, characterized in that the power of the microwave radiation is between 0.8 and 3 kWh per kg of treated textile material. 6. Method according to any one of claims 1 to 5 characterized in that the residence time of said textile material in the chamber is of the order of 60s to 240s. 7. Method according to any one of claims 1 to 6 characterized in that the temperature of said surface is between 40 and 210 ⁰ C. 8. Method according to any one of claims 1 to 4 characterized in that said surface is at room temperature. 9. Method according to any one of claims 1 to 8 characterized by the mixing of the microwave radiation inside the enclosure. 10. Method according to any one of the preceding claims characterized in that the surface capable of being heated is the outer surface of a rotating cylinder. 11. Installation for the continuous treatment of a textile material comprising means for depositing treatment agents on said material, characterized in that it also comprises: a. an enclosure having an inlet opening and an outlet opening of the material; b. means for applying to the textile material a microwave radiation inside the enclosure; vs. a surface capable of being heated and coming into contact with the material during the movement thereof inside the enclosure; d. means for extracting the water vapor formed inside the enclosure. 12. Installation according to claim 11 characterized in that the deposition means comprise means for impregnating said material and squeezing means. 13. Installation according to claim 11 characterized in that the depositing means comprise printing means. 14. Installation according to any one of claims 11 to 13 characterized in that the surface capable of being heated is the outer surface of a rotating cylinder. 15. Installation according to any one of claims 11 and 14 characterized in that said surface is a non-magnetic surface and inert with respect to the chemical compounds used. 16. Installation according to any one of claims 11 to 15 characterized that said surface has a PTFE coating. 17. Installation according to any one of claims 11 to 16 characterized in that the shapes of the inlet and outlet openings are made in such a way that there is no leakage of microwaves. 18. Installation according to any one of claims 11 to 17 characterized in that it comprises means for mixing the microwave radiation inside said enclosure. 19. Installation according to any one of claims 8 to 13 characterized in that the means for extracting water vapor formed inside the chamber comprise either a pressure-reducing system or a ventilation system.