DE2740966A1 - Flame heating fabrics prior to steaming - as preheating during dye fixing - Google Patents

Abstract

Flames are directed on wetted textile prior to its entry to a steaming chamber for dyestuff fixing. The water on the textile is raised to near its b.pt. Condensn. on the fabric during dyeing is avoided. Washing out of the fibre tips is thus reduced, dyed areas have a more distinct outline and residence times in the steamer are reduced. Pref. the flame is produced by gas jets arranged to spread the flame over the whole fabric width. The water in the fabric is raised to within 5 degrees C of b.pt. The water content in the fabric can be =50%. Steaming can be conducted at 102-140 degrees C. Dyeing can be conducted as a one or two phase fixing/dyeing process, e.g. with vat, sulphur or reactive dyes.

Description

A "two-phase process" is a dyeing process in which color

substances and fixatives from different, separate from each other Baths are applied to the textile material and the final dye fixation is generally brought about by thermal action. However, there are too a kind of two-phase procedure in which the final fixation of the applied Dye takes place at room temperature (two-phase cold pad process).

A particularly useful and widely used method of dye fixation in the context of the two-phase process is the continuous steaming process, according to the following the application of dye liquor or printing paste, with or without Intermediate drying, as well as the fixing chemical liquor, the material in a continuous steamer retracted and there the action of a steam atmosphere of about 1G0 ° C for fixation the dyes is exposed (conventional Klotz-Dmpf method). In all In these cases, the textile material is at room temperature when it enters the damper on, it is therefore significantly colder than the steam temperature, which is why there is condensation of steam and thereby a local dilution of the liquor, especially on the surface of the goods comes. The consequence of this is besides "gray veils" (weaker colored fiber tips especially with rayon and woolen fabric) a so-called sooty appearance and possibly also associated with dye migration in the course of the conventional steaming process with reduced color yields.

However, in patent applications P 26 58 863.6 and P 27 13 166.4 In this context it has been suggested how to use the steaming process upstream infrared preheating avoid the difficulties outlined above and achieves very good results in terms of color yield.

So you get a perfect product appearance by the fact that the padded Fabric heated to almost steam temperature with the help of infrared heaters will. The otherwise feared gray veil is excluded in this way.

However, such an infrared preheating is expensive and not problem-free. The main disadvantages are the dependency of such a system on the power supply, the need to preheat the radiant heaters, the afterglow of the same, as well as the high energy demand also comes from a relatively expensive source.

From DT-Gbm 1 904 984 there is a method for predrying textile material known, according to the open flames from burners directly to the through a combustion chamber transported wet web or flammable liquid on the Textiles are sprayed and ignited. According to this state of the art aiming at drying wet and not preheating goods padded with dyes, so that that reference does not make any statements about a possible dye migration in connection with this drying technique.

The object of the present invention is now to provide a To design a method that allows the difficulties outlined above as part of the usual two-phase steaming process for pad dyeing and printing of textile webs with dyes suitable for the type of fiber used as well as for fixing the applied dyes in continuous operation, wherein the impregnated with the aqueous liquor containing the dyes or printed with such an aqueous printing paste, optionally dried in between, and textile material padded with fixing chemicals just before entry in the steam treatment room while maintaining a residual moisture that is clearly is above the swelling water content of the fibers concerned, is preheated to be switched off and to create just as effective preheating as the infrared system allows, but without having to accept their disadvantages.

This object is achieved in that the wet textile web on both sides the effect of one or more open flames directed against the goods exposes, so that the liquor applied at room temperature is close to a temperature theirs Boiling point reached, and then to fix the dyes treated with steam without applying additional pressure.

In this particular two-phase process according to the present one Invention occurs before the steaming process, e.g.

in lightning dampers can be carried out with direct heating Flame rays hitting the fabric. For example, you can use the preheating proceed according to the procedure with the aid of a narrow gate. Similar devices are found in the Textile industry is used for scorching, but has to be built in a more complex way as they are the treatment of dry fabric webs for the purpose of burning them off Fiber and thread ends are used.

The action of the open flame can be in the claimed method It is advantageous to distribute it evenly over the entire width of the fabric with the help of guide plates.

The subject of the invention in question is therefore also a device for preheating textile webs with a direct flame, characterized by that the flame jets known from the narrow streets with the help of baffles be evenly distributed over the width of the fabric and the heating surface in several Zones with different Tcnpaturen is divided.

Through the process of preheating, harmful condensate is formed on the surface of the goods in the steamer prevents dye fixation detrimental dilution of the applied liquor avoided or the consistency of applied printing inks are not impaired, so that dye migration is not can occur. According to the present invention it is thus possible, perfectly Uniform colors and prints with sharp contours and sharp edges To achieve printing areas.

The preheating phase causes the applied liquor to have a temperature reached near their boiling point, the temperature difference to the steam temperature is kept as small as possible and ii should generally not be more than 5oC. Of course With this measure, some of the water evaporates the dye liquid on the surface of the goods as a result of this intense Heat treatment. Care is taken that the loss of moisture within the preheating section remains limited. The residual moisture of the textile material may neither during preheating nor in the course of further treatment below the swelling water content the fiber will sink. (According to Fischer-Bobsien, Internationales Lexikon Textilveredelng + Border areas, 4th edition (1975), the swelling value corresponds to the water retention capacity, i.e. retained% water amount based on dry fiber weight). Through the Reduction in the amount of liquid is primarily a condensate deposit when running in the damp goods in the damper with the effects described avoided. Simultaneously there is an improvement in the liquor ratio, as a result of which the dye yield is noticeably increased, which results in deeper colors. Among those used according to the invention Conditions, the liquor penetrates the entire fabric and also the fiber ends or the fiber tips protruding from the fabric evenly. According to the procedure reliably achieved that no dilution of the liquor due to the action of steam, so there is also no washing out of the fiber tips, which is why an undesirable one The gray haze effect is not noticeable in the goods dyed according to the invention.

As already indicated above, according to the present invention of course, drying of those padded or printed with the dyes Goods to be avoided in any case.

However, this can be done in a simple manner using the speed of the goods rules. Even because of the short distance between the foulard and the steamer, before that There is a risk of drying on after the gas heater is located at the entrance Squeezing greatly reduced. The limited moisture reduction possible with the new process by 25 to 50% - i.e. the amount of fluid originally absorbed is reduced to a maximum of 50% - avoids local drying. A wicking effect of the The goods do not materialize, which is why the dyes cannot migrate.

In the context of the claimed procedure, the fleet must be on the goods can be heated to practically 1000C by preheating.

At such temperatures it takes place - if at all - in the steaming room very little condensation takes place. Less intense warming would have resulted Condensation would result in liquor dilution and would be detrimental to the dyeing result.

The preheating of the dyes just explained padded or printed goods, subsequent steaming process to fix the dyes can by blowing the continuously guided textile material with steam from 110 ° to lo00C in a pressureless room, e.g. on the stenter, or the steam treatment is made in a continuity damper at temperatures of 1020 to 108 "C.

The advantages of the claimed method are that it is easy to regulate the preheating and the low expenditure on equipment of the device used for this purpose. A blind is not necessary for the purpose of metering heat; it is also not a Preheating of the radiator as required or required for IR radiators.

there is no afterglow of the same.

You can use the new process especially when there is a shortage of electricity carry out. In addition, short reaction and fixing times save energy.

As dyes according to the method described, all can be used for the Two-phase process suitable dyes are used. Generally will Vat dyes, reactive dyes and sulfur dyes are used.

The conditions to be complied with according to the invention permit use of fiber types of all common basic substances.

Of course, it is also possible to use the dyeing process and printing on blended fabrics.

Example 1 A cotton fabric is mixed with a printing paste as follows Composition printed: 60 g of the dye Reactive Orange 7 with the C.I. + r.17 756, 500 g neutral thickening on alginate base and 440 g equalizing (thickening or water) to 1000 g and dried.

To fix the dye, a fixing solution consisting of 100 g table salt, 150 g soda lime, 50 g potash and 80 ml sodium hydroxide solution 32.5% and adjusted to a total volume of 1 liter by filling up with cold water has been made with 55% liquor application (of the weight of the goods) by patting on the printed Cotton fabric applied.

Thereupon the wet goods are through the flame area of a V3rrichtung driven according to claim 4, in the - similar to a Gassenge - flames be aimed directly at the wet goods, and thereby preheated. Direct the textile material treated in this way is then placed in a flash damper at 115 ° C. for 8 seconds muffled.

To post-treat the print, the goods are hosed down with cold water and rinsed thoroughly with cold water. Then the goods are rinsed with water at 600C 90 "C with an aqueous liquor with the addition of 0.5 g / l of the reaction product washed from one mole of nonylphenol with 10 moles of ethylene oxide, again with water rinsed and dried.

A full, even, sharp red print is obtained on the fabric.

Example 2 A well prepared, mercerized cotton fabric is padded with a 400C warm, aqueous padding liquor containing: 30 g / l des Reactive Blue 19 dye with the C.I. 61 200 and 10 g / l of the dye Reactive Black 5 with the C.I. 20 505 The uptake of the fleet when padding is 60% (of the weight of the dry goods). The fabric is then dried.

To fix the dye, the textile material treated in this way is now covered with a 200C warm, aqueous liquor with the addition of 200 g / l Glauber's salt Xalz. scwie 20 ml 32.5% sodium hydroxide solution at 50% liquor absorption (of the weight of the goods).

The wet goods are then passed through the flame area of the device driven according to claim 4 (as in example 1) and thereby preheated. Direct then the cotton fabric is steamed for 20 seconds at 1080C.

The aftertreatment of the dyeing takes place in a wide washing machine through in the 1st and 2nd compartment: rinsing at 600C with water in the overflow, 3rd and 4th compartment: Rinse at 800C with water, 5th and 8th compartments: boiling soaps with an aqueous bath containing 0.5 g / l oleylmethyltaurine, 9th compartment: rinsing with cold water.

After drying, a strong, dark blue colored fabric is obtained with good color penetration and perfect levelness.

Claims (4)

Method and device for dyeing and printing of textiles Product webs Patent claims: 1. Process for block dyeing and printing of textiles Material webs with dyes suitable for the type of fiber used and for fixing the applied dyes in a continuous operation according to a two-phase steam process, wherein the impregnated with the aqueous liquor containing the dyes or printed with such an aqueous printing paste, optionally dried in between, and textile material padded with fixing chemicals just before entry in the steam treatment room while maintaining a residual moisture that is clearly is above the swelling water content of the fibers concerned, is preheated, characterized in that the wet textile web on both sides of the action of a or exposed to several open flame (s) directed against the goods, sc that the liquor applied at room temperature reaches a temperature close to its boiling point, and then to fix the dyes without applying additional pressure treated with steam. 2. The method according to claim 1, characterized in that the direct exposure to fluff with the help of a narrow alley or a similarly constructed device performs. 3. Process according to Claims 1 and 2, characterized in that the effect of the open flame with the help of baffles evenly over distributed across the entire width of the goods. 4. Device for preheating textile webs with direct Flame, characterized in that the flame rays known from the narrow street be evenly distributed over the width of the fabric with the help of baffles and the heating surface is divided into several zones with different temperatures.