EP0014919B1 - Method for treating textiles in jet-dyeing devices - Google Patents

Description

The present invention relates to a process for treating strand-like textile material made of natural or synthetic fibers or of mixtures of such fibers, with gaseous and / or liquid treatment agents in jet dyeing plants, the textile material to be treated being introduced into a pressure-tight sealable container, there in endless form circulates and at least for the duration of the treatment operation, during which the treatment agent is circulated in the same direction and thus simultaneously acts on the textile material, and instead of the sole circulation of a treatment liquid in contact with the textile material and possibly in the state of the pull-out phase the goods advance takes place partly by means of the driving energy of a flowing gas. Such a method is known from FR-A-2 214 248.

Methods for treating strand-like textile goods are well known in the textile industry. The main feature of this working technique is that the treatment liquor is circulated in the dyeing apparatus in such a way that it is tangentially pressed onto the textile material, which is combined into a strand and passed past the nozzles, via one or more nozzles, and thus the strand by means of its kinetic energy also set in motion. The result is a circulation of the strand, similar to a reel runner, but here the movement of goods is not caused by the reel train, but by the liquor circulation and the fleet pressure generated in the nozzles.

FR-A-2 390 533 now relates to a method of the type mentioned above (hydraulic goods transport) for pulling dyeing of fiber material with heat-fixable dyestuffs under isothermal conditions, according to which the hot dyeing liquor pressed into the closed dye container already partially transports the textile strand during the liquor filling phase takes over. According to this state of the art, the goods are first preheated in a closed jet with steam. The goods are at rest or are moved by means of the drive roller or reel present in various jet dyeing machines. Under no circumstances does the goods drive take place with the steam blown into the jet for heating. Only when the liquor is transferred from the batch vessel to the jet does it partially take over with the feed of goods through the nozzle, until there is sufficient treatment liquid in the circuit that it can drive the goods solely through the circulation. According to the statements in this FR-A-2 390 533, the goods drive is always dependent on the drive reel or - during the actual dyeing operation - on the presence of liquor in the jet.

Also using a jet dyeing device, a method for wet treatment of continuous fiber materials in a low liquor ratio is described in DE-A1-26 59 086, according to which the drive for moving the textile material through a lifting roller (reel, roller) and through Effect of suction is achieved, the suction effect is provided by a jet nozzle, which comprises the line of goods and sprayed from the outside with a liquid jet of recirculating treatment liquor (in the direction of the flow of goods). In addition, a gas stream is allowed to act on the circulated product / liquor system via a further separate nozzle in order to cause the liquid containing a foam-forming agent to foam. A better distribution of the liquid in the product line is expected. However, this measure also has the consequence that the inert gas mixes with the recirculating liquor and thus exerts additional suction on the product line. Under the given circumstances, there can therefore be no question of the gas flow bringing about the goods drive. Rather, the interaction of lifting roller and the suction effect generated by inert gas and liquor are decisive for the transport of goods.

In all of these known treatment processes using the dyeing jet, the transport of the textile goods through the zone of action is dependent on the presence of treatment liquid (liquor), i.e. The introduction of textile goods into the apparatus itself, which also takes place via the nozzles, presupposes the presence of liquid in the system. In certain cases, especially if a pretreatment of the goods has already been carried out continuously or if such pretreatment is completely dispensed with for reasons of rationalization, in dyeing practice there is a need to introduce the strand-like textile material into a nozzle dyeing system without using a liquid treatment bath.

The process known from FR-A-2214248 goes a certain step further in this direction, in which the goods are advanced for the circulation of goods by means of the drive energy of an inert gas. So little fleet is used here that it can no longer be used for the transport of goods because its quantity is insufficient. This working technique brings the entire treatment fleet by metering it into the driving, cold inert gas stream on the material to be treated. A full come dry loading of the jet with the fiber material is not yet accessible in this way.

Likewise, when performing many dyeing and other treatment processes in jet dyeing systems, it is felt to be disadvantageous that the flow of goods while the treatment fleet is being drained and refilled from another fleet, i.e. with each bath change, even if only briefly, must be interrupted or only maintained with purely mechanical means (reels, rollers). In addition, an impairment of the performance of such known procedures is also seen in the fact that the filling of the dyeing jet with the pretreatment liquor, including the simultaneous drawing in of goods, and the subsequent heating of the textile material by means of steam to the dyeing temperature require separate work steps.

Finally, in all of these known processes, the goods can naturally only be heated via the liquor itself.

The object of the present invention is therefore to enable goods to be transported into or within the system in the case of jet systems which are not or only insufficiently filled with treatment liquid. Such a case is particularly relevant for wet treatment operations if a very short liquor ratio is aimed for.

According to the invention, this object is achieved in that, in the process mentioned at the outset, the kinetic energy which occurs when the liquid coming out of a nozzle or, respectively, comes into contact with the liquid from a nozzle or at least during a substantial part of the total treatment time, at least during the loading / pretreatment stage a nozzle combination under excess pressure exiting gas is transferred tangentially in the direction of travel to the textile material, at least to a significant extent used for transporting the strand of goods into or through the plant, this gas being heated and due to its temperature causing affinity between the treatment agent and the textile material and maintains.

In accordance with the principle of the present invention, to use a gas stream as a drive means for the strand-like textile material, the difficulties which arise when goods are transported solely by means of a liquid are surprisingly overcome. Appropriately and in accordance with the respective procedural measure, the textile goods are transported solely by gas in the fleet-free working phases and by fleet and / or gas in the fleet-using (flooded) phases, with a smooth transition from one drive type to the other being realized leaves.

Due to the spraying of the product line with gas in jet dyeing systems according to the invention, it is now possible to load the system with the textile goods even without liquid, i.e. without the involvement of a pretreatment bath with an empty jet system. For the use according to the new method, the fiber material to be treated can therefore be in a dry or moist state. In many cases, flowing steam is advantageously used as the heated gas, which means that when the dyeing tank is loaded, it is vented and the textile goods and the nozzle dyeing system are heated up evenly and quickly in accordance with the steam temperature. The subsequent treatments in the liquid media can then be carried out isothermally by introducing the treatment liquors at the temperature of the warmed-up textile material. Unnecessary cooling in the intermediate stages of the individual process steps can thus be avoided and necessary reheating avoided.

A particularly valuable application of the method according to the invention relates to the application of heat-fixable dyes according to the exhaust method and consists in that the textile material to be dyed is either after it has been introduced into a dyeing container or after a previous pretreatment combined with the loading process when the textile material is introduced into the dyeing container Steaming is vented and - after sealing this container from the surrounding atmosphere - heated by the steam to about dyeing temperature, then the entire dyeing liquor is filled at about dyeing temperature and with the help of excess pressure acting on the liquor in the closed and steam-filled dye container and in contact with it brings with the textile material, and finally carries out the circulation of the dyeing liquor and the circulation of the textile material under isothermal conditions. By partially or completely operating the jet nozzle (s) with heated gas, usually steam, it is thus possible to also produce piece colorings according to the so-called Rapidcolor principle.

In other cases, air or, where the oxygen contained in it should interfere, nitrogen can be used as a heated propellant to start or stop the flow of goods.

After the dyeing container has been filled with the treatment liquor, the textile goods can now continue to move with both the treatment liquor and the gas stream. In general, in the method according to the invention, in the course of the wet treatment operation, the goods are conveyed by means of a gas flow and by means of the liquor circulation by means of a circulation pump. In addition to such an additional or Only spraying the strand-like textile goods with gas, it is possible to mechanically support the circulation of goods in the jet system at the same time by a driven roller or a roller system.

Because of the measures explained above and also through special precautions which ensure an improvement in the sliding properties of the textile material on the container bottom, it is now possible according to the invention to carry out the treatment process in a very short liquor ratio.

Increased lubricity of the material to be dyed is achieved by guiding the textile material over a multitude of round rods, polygonal rods or lath-shaped profiles arranged parallel to the direction of the flow above the container base.

The smooth surface condition of the above-mentioned sliding devices, made of heat-resistant synthetic material, preferably polytetrafluoroethylene, promotes a uniform distribution of the goods entering the store and their further transport and thus prevents a locally undesired compression of the textile material. The outer diameter of the profiles can be 0.5 to 5 cm, advantageously 1.5 to 3 cm. The sliding device described is generally arranged 1 to 10 cm above the base of the dyeing tank, but this distance is irrelevant for carrying out the method according to the invention.

The lateral spacing of the bars or profiles from one another is chosen in such a way that, depending on the nature of the strand-like textile goods, the goods are guided securely. It is expediently 1 to 3 cm and can be adapted to the requirements.

The precautions according to the method according to the invention furthermore allow the treatment bath to be drained and refilled under isothermal as well as - if not necessary - non-isothermal conditions at temperatures below or above 100 ° C. with simultaneous further circulation of material by transporting the textile goods by means of gas flow. This measure also leads to a considerable reduction in the total treatment time. Undesired downtimes are avoided.

In addition, such a process control enables for the first time several heat treatment steps, possibly even under high temperature conditions, without the goods coming to a standstill and without the textile material cooling in between. This makes it possible to continue the transport of goods without liquor and without heat losses in the intermediate stages of the process. In such a case, the goods are expediently carried out according to the different process stages optionally by gas and / or liquid flow. This variant has a particularly advantageous effect, for example, in the alkalization processes of textile goods made of polyester fibers or threads and subsequent dye treatment.

Another advantage of the new way of working results in dyeing processes of woven goods that contain textured polyester threads, whereby the risk of wrinkles and breakage is significantly reduced by optimal shrinkage initiation. According to the method, the advantages are still present if the subsequent treatment after the first treatment bath is not isothermal.

The terms familiar to the person skilled in the art, jet dyeing system, dyeing apparatus, etc., should be understood in the context of the method according to the invention in such a way that the devices in question can also be used for such treatment operations for finishing the textile material where instead of dyes, others are permanently left on the goods Equipment. However, processes that only serve to prepare goods or post-treatment, primarily washing processes, can also be carried out according to the new principle.

The following examples are only intended to show the possibilities offered by the new process, without restricting it in any way.

example 1

In a nozzle dyeing plant of known design, dry knitwear made of textured polyester fiber material in strand form is run in, the goods being transported by a steam flow from the nozzle system at a set steam pressure of 1.5 bar gauge pressure (about 128 ° C.) and mechanical support by a driven roller he follows.

After the loading process, the fiber material is sewn together in such a way that an endless strand of goods is created. The dyeing jet's entrance opening is then closed and the textile material is re-circulated using a further steam flow (conditions as above). The condensate accumulating in the lower part of the dyeing tank is drained off and collected for further use. The effect of the steam increases the temperature of the textile material circulating to about that of the steam that is pressed in, and the dyeing container itself fills with steam of the same temperature.

in Form einer wäßrigen Dispersion enthält und die auf einen pH-Wert von etwa 4,5 eingestellt ist, aus einem geschlossenen Ansatzgefäß über die Düsen gegen den vorhandenen Dampfdruck (Kondensation) in den Färbebehälter einströmen.After this, 10-minute treatment for heating the textile material, with the help of compressed air, an approx 130 ° C hot, aqueous dye liquor, which - based on the weight of the goods - 0.25% of the disperse dye of the formula

contains in the form of an aqueous dispersion and which is adjusted to a pH of about 4.5, flow from a closed batch vessel through the nozzles against the existing vapor pressure (condensation) into the dyeing tank.

The inflowing liquor continues the transport of the strand of goods and, after the filling process has been completed, the circulation is continued by circulating the liquor by means of the circulation pump. During this treatment phase, the introduction of steam is throttled. With the press-in liquor, the textile material in circulation is now dyed with rapid circulation at a liquor ratio of 1: 5.5 for 20 minutes at about 130 ° C.

The fleet is then drained via the HT drain. The further transport of the textile goods is increasingly taken over by the steam of the nozzles in accordance with the progressive emptying of the dyeing apparatus. The first rinse liquor, which is around 105 ° C., is then introduced into the system without a standstill. The steam supply to the nozzles is then switched off. The goods are now transported solely via the cooling fleet. At about 80 ° C, the commonly used amounts of sodium hydroxide, hydrosulfic and auxiliary agents for carrying out the reductive cleaning are introduced into the bath. After a running time of about 10 minutes under these conditions, this liquor is drained off again and the aftertreatment is carried out. Rinsing finished with warm (approx. 50 ° C) and cold water.

The result is a completely level red color on the knitwear.

Example 2

70 kg of dry cotton jersey in strand form are run into a jet dyeing plant, the goods being transported by a steam stream from the jet system at a set steam pressure of 1 bar gauge pressure (about 120 ° C.) and at the same time by the treatment liquor which is also flowing through the jets. This heats up to 30 ° C and wets the paint through the mechanical action of steam and water flow.

After the loading process, the flow through the nozzles is interrupted and the knitted fabric is sewn together in such a way that an endless strand of goods is produced. The jet system is then vented by briefly operating the nozzles with steam alone. Then the entrance opening of the faffe jet is closed and the textile material is circulated again using a further steam flow (conditions as above) and circulation of the treatment liquor until the temperature of the liquor has reached 60 ° C.

During this process, the aqueous liquor is placed in the order given

• 20 cm³/1 Natronlauge 32,5%ig und
• 2,5 g/I Natriumdithionit

zu und läßt das Vorbehandlungsbad anschließend 5 Minuten zur Verteilung der Substanzen zirkulieren. Dann werden - bezogen auf das Gewicht der trockenen Ware - 3% des Farbstoffes Vat Orange 7 (C.I. Nr. 71105), in etwas Wasser von 40°C aufgeschlämmt, in den Färbejet eingebracht.1 g / l of a sequestering agent based on ethylenediaminetetraacetic acid sodium,

• 20 cm ^3/1 sodium hydroxide solution of 32.5% strength and
• 2.5 g / l sodium dithionite

and then circulates the pretreatment bath for 5 minutes to distribute the substances. Then - based on the weight of the dry goods - 3% of the Vat Orange 7 dye (CI No. 71105), slurried in a little water at 40 ° C., is introduced into the dyeing jet.

With the liquor prepared in this way, the fiber material is dyed for 30 minutes at 60 ° C., the goods being transported exclusively through the circulating liquor.

After the dyeing time has elapsed, the liquor is drained, with steam from the conveying nozzles taking over the further transport of the textile material in accordance with the emptying of the apparatus. The colored goods are then rinsed by adding cold water. The rinsing is therefore seamless and without downtime.

The transport of goods by means of steam is maintained until there is enough water in the apparatus and this alone can take over this function. As soon as this is the case, the steam supply to the nozzles is switched off.

The rinse water has now reached a temperature of 30 ° C. The coloration is now rinsed clear by adding cold water in the overflow. Thereafter, the water supply is turned off for dyeing jet, the water in the apparatus at 30 ° C. and 33% for a treatment of 10 minutes, the applied to the leuco compound is Paser strength by the addition of 2 cm ^3/1 hydrogen peroxide is oxidized to the insoluble vat dye. The dyeing is then rinsed again without supply of cold water in the overflow.

After drying you get a level orange color of the jersey. The dyeing operation carried out here is distinguished by the following advantages: the seamless transition from one dyeing step to the other saves 20-30 minutes of dyeing time as a result of the measures according to the invention. Hydrosulfite consumption is reduced by approx. 10% compared to conventional methods.

Claims (12)

1. A process for treating a textile material in rope form made of natural or synthetic fibers or mixtures of such fibers with a gaseous and/or a liquid treating agent in a jet dyeing apparatus wherein the textile rope to be treated is introduced into a vessel which can be tightly closed against the surrounding atmosphere and, in an endless form, is circulated therein at least for the duration of the treatment period, during which period the treating agent is circulated in the same direction, thereby effecting simultaneous action on the textile material, and wherein, instead of transporting the textile rope, during all of said treatment period, by circulation of the liquid treating agents with which the textile material is in contact and optionally in condition of exhausting, the advance of the textile rope is performed by means of the propulsion energy of a circulating gas, which comprises using, at least for a substantial part of the whole duration of the treatment period, in any case at the stage of a charging/preliminary treating operation and during an liquor exchange of different liquid treating agents, the kinetic energy, which is transmitted when a gas issuing under excess pressure from a nozzle or combination of nozzles in said apparatus impinges on the textile rope tangentially in the direction of motion of the rope, at least in substantial part, for the transport of the material rope into and through said apparatus, said gas being heated and due to its temperature being capable of effecting and maintaining affinity between the treating agent and the textile material.

2. A process as claimed in claim 1, wherein the material transport due to said gas- impingement is assisted mechanically with a driven roller or a roller system.

3. A process as claimed in claim 1 or 2, wherein the material transport due to said gas- impingement is assisted by circulating a liquid treating agent in the direction of material transport.

4. A process as claimed in claim 1 or 2, wherein the material transport by said gas- impingement is continued during discharging and re-charging of a liquid treating agent.

5. A process as claimed in claims 1 to 4, wherein the material transport is effected alternatively, from one successive different treatment stage to the next, by the circulating gas and/or by the liquid agent.

6. A process as claimed in claims 1 to 5, wherein air or nitrogen is used as the gas issuing under excess pressure.

7. A process as claimed in claims 1 to 5, wherein steam is used as the gas issuing under excess pressure.

8. A process as claimed in claim 7, wherein steam is used for simultaneously deaerating the textile rope and the treatment vessel, as well as for heating said rope and vessel to approximately the temperature of a subsequent wet treatment operation.

9. A process as claimed in claim 7 or 8, wherein steam of approximately the same temperature as that of a subsequent wet treatment operation is used.

10. A process as claimed in claims 7 to 9, wherein following the action of the steam on the textile rope an isothermal dyeing operation according to the batchwise exhaustion technique is performed.

11. A process as claimed in claims 7 to 10, wherein for dyeing according to the batchwise exhaustion technique with a dyeing liquor which is a liquid treatment agent containing a thermofixable dyestuff suitable for the respective fiber type, the textile rope to be dyed is deaerated with steam directly after the rope has been introduced into the dyeing vessel, or after a preliminary treatment in combination with the introduction of said textile rope in said dyeing vessel; and after having tightly closed said dyeing vessel against the surrounding atmosphere, said textile rope is heated to substantially the dyeing temperature with steam; then the entire amount of dyeing liquor, at substantially the dyeing temperature and under an excess pressure, is rapidly forced into the closed dyeing vessel containing steam, thereby contacting said liquor with said textile rope; and finally recirculation of said dyeing liquor and circulation of said textile rope is performed under substantially isothermal conditions under at least autogenous pressure.

12. A process as claimed in claims 1 to 11, wherein several heat treatment operations are carried out successively, each by means of a gaseous and/or a liquid treating agent, without a standstill and without cooling of the textile rope, under isothermal conditions.