EP0797698B1 - Device for fixing dye in reactive dyeing - Google Patents

Abstract

The invention concerns a dye-fixing device for use in the reactive dyeing of cellulose articles (6), the device comprising a dyeing fluid (10) containing the reactive dye. The impregnated article (6) is treated in an air dryer (14) comprising a chamber (15) with an inlet and an outlet (16, 17) for the articles, an extraction duct (24) and a circulating fan (36). According to the invention, until the article (6) reaches the chamber outlet (17), the residual moisture in the article is maintained at a minimum value at which the dye reacts with the cellulose fibres. Simultaneously, and irrespective of the weight of the article, a given water vapour content is set in the air in the chamber. To this end, water vapour injectors (30) are provided in the chamber (15), in addition to the extraction duct (24), and associated with a common first controller (34) which regulates the chamber climate as a function of a climate-measuring device (35). The chamber temperature is additionally regulated by a second controller (38) which controls the circulating fan (36) as a function of a residual moisture measuring device (37) associated with the article (6) at the chamber outlet (17).

Description

The invention relates to a device for fixing color when Reactive dyeing of cellulose ware with an application pad a dye liquor containing the reactive dye on the Goods and with an air dryer downstream of the foulard (see e.g. DE-A-1460769), the one chamber with goods inlet and outlet and with controllable Has suction channel and controllable circulation fan. Prefers The circulation fan sucks the air with the help of a fan via a heating register. The fan and / or that Heating registers can be controllable. One can therefore also from a circulating fan heater.

The device is preferably provided for a reactive dyeing process with a fleet of colors, which tools for Binding the reactive dye to the cellulose fibers, to execute. In the context of the invention, the term "cellulose ware" includes textile webs of cellulose yarn or fibers, including cotton, viscose, PES / viscose, PES / Co, Viscose / wool, PA / wool, modal fibers and the like. If it is said that the air dryer has a chamber with incoming and outgoing goods -Exhaust and with suction duct and circulation fan, so will thus at the same time a plurality of at least two chambers Inlets and outlets and / or a plurality of at least two Suction channels and circulation fans per chamber.

For the continuous dyeing of knitted or woven goods, e.g. also from 100% cellulose, with reactive dyes Mainly four processes used worldwide, namely the Pad batch process with a cold residence time between the Padding and washing, the pad-dry heat-setting process with a dry and a hot air fixing passage between padding and washing, the pad-steam process with a steaming passage between fouling and washing and the pad-dry-pad-steam process with an intermediate drying stage and a steaming level between fouling and washing.

The reactive dyes used can be after Strength of your reactivity. The reactivity the dyes have an influence on the duration of the residence time Pad-batch process, on temperature and time in the pad-dry heat setting process and on temperature and time in the pad-dry-pad-steam process. The amount of color yield and / or the degree of fixation depends on the reactivity. One in The following series have increasing reactivity also in cold dyeing systems with dyes to be used at 40 ° C: Monochlorotriazine, vinyl sulfone, dichloroquinoxaline, monofluorotriazine, Difluorochloropyrimidine and dichlorotriazine.

In order to bind the reactive dye into the fiber, depending on Process from the inking units to the most diverse types of tools and quantities recommended. For example, come with the pad batch process up to 30 g / l soda, 35 ml / l NaOH 38 ° Bé, 70 ml / l water glass 37 - 40 ° Bé and 80 g / l urea in question. At the Bad-dry heat setting processes are used up to 30 g / l soda, 5 g / l table salt, 20 g / l sodium bicarbonate and 200 g / l urea and the pad-steam process and the pad-dry-pad-steam process up to 30 g / l soda, 20 ml / l NaOH 38 ° Bé and 250 g / l table salt / Glauber's salt used. These tools, especially caustic soda, water glass, soda, urea and table salt, that are used in relatively high amounts go with the intended application partly in the exhaust air, the largest But part of it after washing after fixing the color into the sewage.

In an effort to reduce the exhaust air and waste water during reactive dyeing of cellulose to prevent the necessary Reduce machinery and reduce the dyeing process Energy expenditure in less time than before can, the inventor came to the realization that reactivity of the dyes themselves with the drying behavior of the treated To connect goods so that an optimal Color yield without the high or aggressive amounts of auxiliaries, such as urea, water glass, soda, sodium hydroxide solution and / or Cooking salt can be achieved (see e.g. DE-A-2552 562).

Accordingly, the invention has for its object a device to create that allows the reactivity of the deployed Dyes with the drying behavior of this product to be connected in such a way that an optimal color yield already without the aggressive amounts of aids mentioned in one combined - preferably continuous - dwellings Drying process can be achieved.

For the device described at the beginning with an air dryer, the one chamber with goods inlet and outlet as well as controllable Has suction channel and controllable circulation fan the solution according to the invention in that the chamber controllable Steam injectors have one in the chamber on the Control means of suction channel and steam injectors switched Kliwaweßgerät for regulating a predetermined steam content in the air circulation is provided and that the goods at the goods outlet Output residual moisture meter in control connection with the circulation fan for regulating a still reactive residual moisture is assigned to the goods up to the goods outlet.

The invention ensures that in the chamber or in Air dryers maintain a certain vapor content in the air and to ensure that the goods at the exit of the Chamber still has a reactive residual moisture. At the same time is achieved that regardless of the weight of the goods, the means also independent of that with the goods in the dryer or the chamber introduced amount of water, constantly, too for lightest goods, a certain, predetermined steam content is adjustable in the air of the chamber.

When applied, it turned out, among other things, that one except the respective reactive dye as an aid (for binding of the dye to the cellulose fibers) exclusively Wetting agent and sodium bicarbonate (NaHCO3) or similar dye liquor containing weak alkali excellent dyeing results delivers when the cellulose ware soaked in the liquor in an air dryer by indwelling treatment of on the order of 2 minutes with an order of 25 minutes Vol.% Steam content of the air is fixed. When trying could the numerical values 1 to 3 minutes and more and from 15 vary up to 50 vol.% or more.

According to the invention, the chamber should have controllable steam injectors. This means that the chamber means for controlled injection of steam. Every chamber can be any number of steam injectors, including the number one. The steam injectors and their Control means should be designed so that the steam inlet to shut off completely or gradually from zero to a maximum is to be switched on. There will be more or less large amounts of steam required if the vapor content of the chamber air is below a given measure would fall. For example occur when the goods entering the chamber are not enough Carries liquid with it. On the other hand, is the steam content of the Chamber air - measured by a Kliwa measuring device - becomes too large Regulated air extracted with the suction channel until the predetermined steam content (in vol.%) is set.

Adherence to the aforementioned chamber climate is admittedly for the Procedures important, but not sufficient, must be added a specified retention time of the goods in the ready to react Status. So it must be prevented that the goods before expiration the dwell time reaches a state in which the applied Dyes no longer or no longer sufficient can react with the cellulose fibers or the like. The is generally the case if the goods have a minimum residual moisture, e.g. - depending on the type of goods - 10 to 30% of the weight of the goods, falls below.

For the appropriate regulation of the chamber climate therefore points the device according to the invention at the goods outlet of the chamber or just behind the outlet outside the chamber, a residual moisture meter, the so-called initial residual moisture meter, with which the measure of the residual moisture is measured, which the goods are still in possession when they have passed through the chamber is. Depending on the measurement results of this initial residual moisture meter will the circulation fan or the circulation fans of the dryer controlled so that the drying performance the dryer, preferably by reducing the speed the circulation fan is reduced until the goods at the chamber exit has the required minimum residual moisture.

If the device according to the invention two or more in a row switched air dryer chambers, it is sufficient in general, the chambers overall a single output residual moisture meter to be assigned to the last chamber at the goods outlet. If it is not certain that the goods are already at the goods entrance has the required minimum residual moisture, can also an input residual moisture meter at the entrance to the chamber or chambers be set. With this device you can, if necessary upstream device for diving or wetting the goods with the liquor or squeezing the liquor and / or controlled to moisten the goods.

The goods can be in the area between the foulard and the chamber entrance also a colorimetry regulating the foulard according to EP 0 411 414 B1 can be assigned. The moisture and color measuring devices are preferred to combine. This is especially true, for example then when the measurements reciprocate over the Width of the goods or web should extend.

According to the above, it can be said that the invention Device wise - apart from the regulation of the color distribution according to EP 0 411 414 B1 - preferably two control loops, namely a first control loop with a first controller for control the circulating air volume and thus the dryer output chamber temperature via the circulation fan depending on the Output residual moisture of the goods and a second control loop and a second controller for regulating the chamber climate by optional Activate a fan in the extraction duct or one Valve for blowing steam through the steam injectors into Dependence on a climate measurement in the chamber.

In the device according to the invention, the earlier are Coloring processes used aggressive or environmentally harmful Aids to a certain extent through a controlled steam content substituted on drying. In individual cases you can use liquor be worked on, which are only about 1 contain up to 2 g / l wetting agent and about 10 g / l sodium bicarbonate. The larger the result, the better the coloring results Reactivity of the dyes used. In this Reactive substances have proven to be particularly favorable the base of dichlorotriazine. Improvements and further refinements the invention are specified in the subclaims.

Based on the schematic representation of an embodiment details of the invention are explained.

This system shown has an inlet area 1 with Dock 2, trough 3 and high inlet 4. The in the direction of transport 5 running textile web 6 is following the trough 3 fed to a dyeing pad 7 with a liquor trough 8 and a squeezer 9, provided with liquor 10 and in the squeeze 9 evenly drained. After a short air passage 11 - if necessary with moistening device 12 - and possibly with compensator 13, the web 6 is an air dryer, in the exemplary embodiment, this is a hot flue 14. Of the The contents of the hotflue should be so large that the invention preferred residence time can be maintained.

The moistening device 12 is preferably used when starting up the system for moistening a precursor / follower and for Establishing the required chamber climate within the Hotflue 14 enclosing chamber 15 used. The chamber 15 has a goods inlet 16 and a goods outlet 17. In the Chamber are two rows of in the embodiment Guide and conveyor rollers 18, over which the web 6 in meandering is redirected. The material web treated in hotflue 14 6 can be the goods 6 following the goods outlet 17 for example via a trough 19, a high outlet 20 a dock 21 wound or directly to a washing machine, e.g. via a compensator 22 to a washing machine 23 or the like.

Features preferred within the scope of the invention are a suction channel 24, the floor inlets 25 and ceiling inlets 26 within the chamber 15 may have and the one at its outlet 27 Has fan 28 with frequency or speed controlled motor. The suction channel 24 is therefore able to control of the exhaust fan motor more or less accordingly or withdraw no exhaust air 29 from the chamber 15 at all. Basically can this regulation also by controlling the associated Heating register or its heating medium. The fan motor generally follows any control commands more elastic than a heater.

Another preferred feature of the device according to the invention are steam injectors 30, e.g. at the bottom 31 of the chamber 15, which have a controllable valve 32 (or a controllable valve Valve) or shut off with more or less steam a corresponding steam source 33 are to be supplied. Prefers the fan 28 and the steam injectors 30 become a first Assigned controller 34, which depending on the one within the chamber 15 arranged control measuring device 35 obtained Climate values - vapor content of the air in chamber 15 - the Should regulate chamber climate. Then the first controller 34 should either the steam content of the chamber climate by starting the Reduce fan 28 or increase fan speed or enlarge by starting the steam injectors 30. The first controller 34 accordingly belongs to a first control loop to regulate the chamber climate with the help of the fan 28 or the steam injectors 30 depending on those with the climate meter 35 determined value of the vapor content of the chamber air.

Further preferred features of the device according to the invention are those in chamber 14 (optionally preferred in each Chamber) arranged circulation fan 36 and a at the goods outlet 17th or output residual moisture measuring device positioned immediately afterwards 37. The latter is switched to a second controller 38, which controls the circulation fan or fans 36. The second Controller 38 thus forms the circulation fan 36 and the Output residual moisture meter 37 a second control loop.

The first control loop with the first controller 34 comprises the chamber climate measuring device 35, not just the fan motor 28 of the suction channel 24, but also - alternatively - the valves 32 of the steam injectors 30 controls. With the first controller 34 the vapor content of the air in the chamber 15 can therefore be independent are regulated by the amount of moisture - currently or goods dependent - transported with the goods 6 in the chamber 15 becomes. The amount of moisture also depends, for example, on the weight of the goods from. A lot of moisture becomes with heavy goods, with lighter Goods brought little moisture into the chamber 15. With the suction channel 24 the humidity can be reduced. An important Aspect of the invention is therefore that alternative to the suction channel 24 steam injectors 30 are provided. With With the help of the steam injectors 30, the steam content of the air in the chamber 15 can be increased if the incoming goods 6 does not bring enough moisture into the chamber.

One aspect of the method, the implementation of which is the inventive Device serves is a certain length of stay to ensure the goods 6 in the chamber 15. While the goods must be at least as long as the total length of stay be damp that the applied liquor in the desired React way with the cellulose fibers or the like can. Since the goods at the entrance to the chamber, at the goods inlet 16, comes practically immediately from the foulard 7, she has there is generally sufficient residual moisture there. If that should not be the case, the humidifier 12 can be switched on. For possible inspection of the goods 6 at the goods inlet 16 can therefore an input residual moisture meter 39 are provided.

As said, the device according to the invention enables Goods 6 to the chamber exit, at the goods outlet 17 so damp keep the system ready for reaction to the goods and applied paint liquor for binding the color to the cellulose fibers remains. To control and maintain this condition the second control loop with the second controller 38 according to the invention intended. Provides, for example, the output residual moisture meter 15 a residual moisture is too low, so the amount of circulating air is reduced by the second controller 38 the speed of the circulation fan or fans 36 is reduced, so that the goods dry more slowly.

If, for example, a product with 200 g / m ² with 70% residual moisture enters chamber 15 and leaves the chamber after the prescribed dwell time with 15% residual moisture, a product with only 100 g / m ² and also 70% residual moisture would enter the chamber ( Goods inlet 16) under otherwise identical conditions already have a residual moisture of 15% within the chamber 15 - perhaps after about half the prescribed dwell time - and then be too dry for a further reaction of the dye liquor and cellulose ware. In order to avoid this, in the device according to the invention, the amount of circulating air is reduced via the speed of the circulating fan 36 so that the light goods leave the dryer with at least the same residual moisture of 15% as the heavy goods. For example, it may be necessary for the second controller 38 to reduce the speed of the circulation fans 36 to approximately half the value.

If, on the other hand, a heavier product with, for example, 400 g / m ² also enters the dryer with 70% residual moisture, when the circulation fan 36 is set corresponding to the product with 200 g / m ^2, the product will leave the dryer with about 30% residual moisture. In this case, the dwell time (of the reaction-ready goods) is respected in any case. However, one can increase the speed of the circulation fans 36 - if this is possible - so that a faster drying takes place; for the result of the color fixation, however, the residual moisture with which the goods 6 leave the hot flue 14 does not matter if only the prescribed minimum moisture is present.

The invention provides a device with which it is possible to use a method for color fixing in reactive dyeing of cellulose ware or cellulose fibers of all kinds in one Color liquor, the tools for binding the reactive dye to the cellulose fiber contains, the cellulose ware fouled with the dye liquor in an air dryer a duration treatment with a given duration subjected to the predetermined vapor content of the air in the drying chamber can be. In the device, the residual moisture Cellulose ware kept at a value until the exit of the chamber, in which the reaction of the dye with the cellulose fibers takes place. At the same time, regardless of the weight of the goods, that means also independent of the one with the goods in the Amount of water introduced into the dryer, constantly - even at lightest goods - a certain vapor content in the chamber air adjustable.

Reference list

1 =

Infeed area

2 =

Docke

3 =

trough

4 =

high enema

5 =

Direction of transport

6 =

Would

7 =

Dyeing pad

8 =

Fleet trough

9 =

Squeeze

10 =

Color fleet

11 =

Air passage

12 =

Humidifier

13 =

Compensator

14 =

Hotflue

15 =

Chamber (14)

16 =

Goods entry

17 =

Goods outlet

18 =

Guide and conveyor roller

19 =

trough

20 =

high spout

21 =

Docke

22 =

Compensator

23 =

Washing machine

24 =

Suction channel

25 =

Floor inlet (24)

26 =

Ceiling inlet (24)

27 =

Outlet

28 =

fan

29 =

Exhaust air

30 =

Steam injector

31 =

ground

32 =

Valve

33 =

Steam source

34 =

first regulator

35 =

Climate measuring device

36 =

Circulation fans

37 =

Initial residual moisture meter

38 =

second controller

39 =

Input residual moisture meter

Claims (7)

1. Device for fixing dyes on reactive dying cellulose articles (6) with a padding machine (7) for applying a dye bath (10) containing the reactive dye onto the article (6), and with a dehumidifier (14) connected after the padding machine (7), which dehumidifier comprises a chamber (15) with an inlet and outlet for the article (16, 17) and with a controllable suction channel (24) and controllable circulating fan (36), characterised in that the chamber (15) has adjustable steam injectors (30), in that in the chamber (15) a climate measuring device (35) connected to the control means (34) of the suction channel (24) and steam injectors (30) is provided for adjusting a given steam content in the recirculated air, and in that the article (6) at the outlet (17) is assigned an exit residual moisture measuring device (37) in control connection with the circulating fan (36) for adjusting the still potentially reactive residual moisture of the article (6) up to the article outlet (17).
2. Device according to claim 1, characterised by a first control unit (34) for controlling the chamber climate by the optional triggering of a ventilator (28) in the suction channel (24) or a valve (32) for injecting steam through the steam injectors (30) in dependency on the climate measurement in the chamber (15), and a second control unit (38) for controlling the chamber temperature by means of the circulating fan (36) depending on the output measurement of residual moisture in the article (6).
3. Device according to claim 1 or 2, characterised in that the suction channel (24) comprises a ventilator (28) with a speed-controlled drive motor.
4. Device according to at least one of claims 1 to 3, characterised in that between the padding machine exit and the article inlet (16) of the dehumidifier (14) there is an air passage (11) that is short compared to the time the article (6) spends in the dehumidifier.
5. Device according to at least one of claims 1 to 4, characterised in that at or immediately in front of the article inlet (16) of the chamber (15) an input-residual moisture measuring device (39) is assigned to the article (6).
6. Device according to at least one of claims 1 to 5, characterised in that at least one hot flue (14) is provided as the dehumidifier.
7. Device according to at least one of claims 1 to 6, characterised in that, in particular on using a dye bath (10) containing only wetting agents and a weak alkali such as sodium bicarbonate in addition to the reactive dye as an additive for binding the dye onto the fibres of the article (6), the climate and residual moisture measuring devices (35, 37) assigned to the chamber (15) and the article (6) and the control units (34, 38) of the suction channel (24) and the steam injectors (30) controlled by the results of the measurements on the one hand and the circulating fans (36) on the other hand are designed to provide a drying time of the reactive damp article (6) in the dehumidifier of a given period, in particular about 2 minutes, with a given steam content of air, in particular in the order of 25 vol. % steam content.

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