DE3922601C2 - Method and device for low-temperature plasma treatment of textile substrates - Google Patents

Description

The present invention relates to a method with the features of The preamble of claim 1 and a device for carrying it out of the method with the features of the preamble of claim 15.

Methods and devices have already been described for Sheets or yarns for a low-temperature plasma treatment subject.

DE-OS 33 12 307 describes a device and a method for Low temperature plasma treatment of fabrics and skeins. Here becomes an endless web of fabric or web between two Rolled bobbins, being between the first bobbin and the Distance from the first winding body arranged second winding body plate-shaped pair of electrodes is provided. When wrapping the endless Material web of the fabric or the skein is the fabric or the  Strand of yarn between the two plates of the pair of electrodes with one continuous speed passed, so that in the known Method or in the known device always only a single layer Low temperature plasma treatment takes place.

Similar methods or devices for continuous treatment of textile products with the help of a low-temperature plasma are also in the publications DE 33 12 432 A1, DE 33 00 095 A1, DE 32 48 730 A1 and DE 32 48 590 A1 are disclosed.

Such, on a continuously moving web of goods Fabric or a strand of yarn are performed not without problems. For example, it can be used here Wrapping the web to a disturbance in the winding process come, i.e. for example the fabric will not edge on Edge wrapped, which in turn leads to an unwanted Laying and the risk of imposition of the wrap occurs. This in turn leads to manual correction is required, which is very expensive because of this the low-temperature plasma treatment is interrupted and the The autoclave must be ventilated. They also require known methods an always constant transport speed, otherwise the low-temperature plasma treatment induced changes in properties of the treated material seen over the length of the web are uneven. This is also the reason why Such methods have not yet been put into practice have prevailed, especially in the known method in one relatively low throughput requires a lot of effort is.

The present invention has for its object a method of to provide the specified type, that for flat structures or for the fibers, filaments used for the manufacture of fabrics and / or yarns over their length and possibly width seen a special allows even treatment.  

This object is achieved according to the invention by a method with the Drawing features of claim 1 solved.

According to the invention is thus a method for treating fabrics or fibers, filaments and / or yarns used for the manufacture of fabrics with the aid of a low-temperature plasma, which is in the presence of a reactive gas at a pressure between 10 ^-1 Pa to 10³ Pa and a frequency between 1 MHz and 81.36 MHz or 2.54 GHz during a total treatment time of 2 to 30 minutes. In this case, before the low-temperature plasma treatment, a heap is first produced from the flat structures or from the fibers, filaments and / or yarns used for the production of the flat structures and then the heap is subjected to the low-temperature plasma treatment, during which the low-temperature plasma treatment gas that is not being moved flows through a gas. In contrast to the prior art mentioned at the outset, the substrate to be treated in the process according to the invention is therefore not plasma-treated in the form of a single-layer web, but rather as a heap, whereby under heap each ordered, evenly flowing multi-layer arrangement of the substrate to be treated, for example in the case of fiber tapes ( Card tapes), filaments, yarns or flat structures in the form of a winding body, in the case of fibers, filaments, yarns in the form of a muff or strand or in the case of fibers (flakes) in the form of a press cake.

In the present text, every three-dimensional is supposed to be under flat structures textile structures, such as a woven fabric, a knitted fabric, a Knitwear, a fleece, a card sliver or a velor, understood become.  

The method according to the invention has a number of advantages. So allows treatment of the aforementioned in a particularly simple manner Substrates, since these substrates are not like the ones listed at the beginning State of the art, are plasma treated during rewinding, but the substrates stationary during the low-temperature plasma treatment remain, so that the disturbances described above in the Invention according to the procedure. This in turn leads to the Low temperature plasma treatment does not have to be interrupted, which is the Reproducibility and uniformity of the inventive Ensures process-induced effects. Also could be more surprising be found that the low-temperature plasma treatment effects caused by the thickness of the pile are even, so no difference in treatment effects between the inner ones Layers, the middle layers and the outer layers of the pile occur. The reason for this is believed to be the obvious fact that the Low temperature plasma treatment formed electrons, ions, neutral Molecules and / or radicals that crosslink, oxidize, roughen and / or etching with the surface of the material being treated react, be distributed evenly over the thickness of the pile, so that the aforementioned non-uniformities over the thickness of the Haufwerkes seen in the method according to the invention do not occur. This even distribution is obviously related to the fact that Heap during the low-temperature plasma treatment with the gas, which as Carrier for the aforementioned electrons, ions, highly reactive molecules and / or radicals, without formation of deadly areas is evenly flowed through and that, for example, at a Flow through the pile viewed from the inside in no increased concentration on the inner layers of the pile Electrons, ions, highly reactive molecules and / or  Radicals are trained. Rather, it can be assumed that there is always one constant saturation concentration of the aforementioned particles the surface forms, so that uneven treatment effects on the Seen the thickness of the pile can not occur. So could For example, it can be found that the staining behavior caused by a low temperature plasma treatment is affected between the inner substrate layers, the middle substrate layers and the outer Substrate layers of a treated according to the inventive method Substrate is not changed, which by appropriate coloring tests and subsequent colorimetric evaluation was checked. Also the Wetting ability, particularly in the case of synthetic fibers through a Low temperature plasma treatment is affected, results between the inner layers, the middle layers and the outer layers none Differences, as determined from appropriate experiments could be.

Also have coatings or pigment prints that are based on fabrics are applied by the method according to the invention before the order were treated, compared to non-treated fabrics much better adhesion, which results in reduced abrasion and expresses better fastness. In addition, it was found that fibers, filaments, yarns or corresponding fabrics in particular made of polyester, polyamide and / or polypropylene, according to the Invention treated in accordance with the procedures, a much lower Surface resistance compared to untreated substrates exhibit, this lower surface resistance was permanent. At the treatment of a polyethylene and a polypropylene fiber fleece found that the fleeces each compared to a corresponding non-treated fleece has a significantly higher water content had acquisition and water storage capacity, so that overall due to  Favorable property changes of the previously described, for example substrate treated according to the method of the invention appropriate procedures with a high throughput of goods are particularly economical and is easy to do.

The low temperature is usually used in the method according to the invention Tur plasma treatment at a vacuum between 5 Pa and 500 Pa carried out. You get particularly good results if you use the Low temperature plasma treatment at a vacuum between 50 Pa and 300 Pa, preferably between 70 Pa and 200 Pa.

Another embodiment of the method according to the invention provides that the low temperature plasma treatment in at least two Carries out treatment periods, these treatment periods preferably distinguish by the treatment pressure. This is how it looks Embodiment of the method according to the invention that first a pressure between 5 Pa and during a first treatment period 120 Pa, preferably between 70 Pa and 120 Pa, and during a subsequent second treatment period between 130 Pa and 250 Pa, preferably between 130 Pa and 200 Pa. Such a pressure change ensures that the pile flows particularly well and evenly through the gas is seen so that unevenness across the thickness of the pile be completely avoided. The first treatment preferably closes period immediately after the second treatment period, and in particular, both treatment periods alternate repeated several times.  

In the previously described embodiment of the invention It is possible to measure the different treatment pressures abruptly stop the first and second treatment periods, d. H. the previous one mentioned treatment pressures to increase or decrease abruptly. Becomes however, a winding body of this type according to the method according to the invention treated, there is a risk that the winding body from the Carrier sleeve detaches, which ensures a uniform flow through the Viewed over its thickness winding body is no longer guaranteed. Around Avoiding this is a further development of the previously described Embodiment of the method according to the invention that the pressure increase in the transition from the first to the second treatment period or Lowering pressure during the transition from the second to the first treatment period continuously, preferably in the form of a sinusoidal Pressure curve is carried out. This pulsates the winding body or gas flowing through the pile at a frequency which is the same as its length Duration of the first and second treatment period corresponds.

Usually in the method according to the invention first and second treatment periods each over a period of time from 10 seconds to 160 seconds, preferably between 20 seconds and 60 seconds.

To the influence of foreign gases in the method according to the invention exclude and thus reproduce the result of the treatment particularly to design bar, sees a further variant of the invention Procedure before that at the beginning of the low-temperature plasma treatment sets a pressure that is less than the pressure during the Low temperature plasma treatment and that you can then adjust supplies the gas to the required treatment pressure. By such Procedure is also ensured that at the beginning of the Low temperature plasma treatment the gas flows through the heap so that Foreign gases are displaced within the pile.  

Regarding the frequency in the low temperature plasma treatment to note that this varies in particular between 1 MHz and 20 MHz. Particularly good ones Results are achieved in the method according to the invention if the Frequency of the low-temperature plasma treatment is 13.56 MHz.

There is also the option of using the low-temperature plasma Treatment at a frequency of 27.12, 40.68 and / or 81.36 MHz to lead. Of course, it is possible to use the low-temperature plasma act not only with one frequency but also with several frequencies to make.

With regard to the power density in the method according to the invention, it should be firmly stated that this depends in principle on the amount of the pile, the effects brought about by the low-temperature plasma treatment and the selected frequencies. Usually, at the aforementioned frequencies, the power density in the low-temperature plasma treatment varies between 2 W / dm ³ and 25 W / dm ³ , preferably between 8 W / dm ³ and 14 W / dm ³ , the aforementioned powers being based on the volume of the particular autoclave used.

Particularly good results can be achieved in a further embodiment of the method according to the invention if one works at a frequency of the low-temperature plasma treatment of 2.45 GHz. Here, the pressure preferably varies between 70 Pa and 120 Pa, while the power density in such a treatment between 0.1 W / dm ³ and 5 W / dm ³ , preferably between 1.5 W / dm ³ and 3 W / dm ³ , lies.

In principle, any gas can be used in the process according to the invention which forms or emits ions, highly reactive molecules, radicals and / or electrons under the influence of the gas discharge, which then, as stated above, with crosslinking, oxidation, roughening and / or etching of the React surface of the plasma-treated material. For example, as a gas in the process according to the invention, O ₂ , O ₃ , CO ₂ , CO, N ₂ O, NH ₃ , SO ₂ , SiCl ₄ , CCl ₄ , CF ₃ , Cl, CF ₄ and / or SF ₆ can both be used as Individual gases as well as gas mixtures are used, with particularly good results being achieved using oxygen. If, on the other hand, a chemical modification of the surface, for example plasma polymerization or plasma graft polymerization, is desired in the process according to the invention, appropriate monomers are used for this purpose, which self-crosslink and / or react with the surface of the treated substrate.

The treatment time in the method according to the invention, as mentioned, between 2 minutes and 30 minutes is like the power density depends on the quantity of the pile and the extent of the desired effects.

If the method according to the invention is used for fabrics, filaments or If yarns are used, the pile is preferably made by winding the fabrics, filaments or yarns on a perforated sleeve forth, so that a winding body produced in this way correspondingly well from the gas can be flowed through. It is particularly advantageous if you have a perforated metal sleeve is used because this metal sleeve is still considered can use another electrode, as described below becomes.

To ensure a particularly even and good flow through the pile with the Ensure gas, especially in the case of large-volume and / or dense If piles are required, it is advisable to alternate the piles to flow through with the gas from outside to inside and from inside to outside. This can be done, for example, in the method according to the invention  achieve that in the first treatment period described above Heap from the inside out and in the second one that follows Treatment period the pile from the outside in or vice versa flows through, so that in addition to the pressure change described above during the low temperature plasma treatment also the direction of flow of the gas is changed.

The invention is also based on the object of a device to carry out the method according to the invention To provide that using relatively few Components a particularly flawless and even treatment of the substrate.

This object is achieved by a device with the characteristics Drawing features of claim 15 solved.

The inventive device for performing the method has a essentially cylindrical reaction chamber, at least two at a distance electrodes arranged from each other, a voltage source for the Electrodes, a vacuum source connected to a gas discharge device and a gas supply device. Here is inside the device a mounting device for the pile is provided while the Electrodes are arranged so that the pile between the Electrodes.

The device described above has the advantage that it Comparison to the prior art described in the introduction according to DE-OS 33 12 307 has a relatively small size because the Device according to the invention on large-volume unwinding or winding device lines and associated drive units can be dispensed with. This  in turn, causes the vacuum source, which is preferably a conventional vacuum pump is compared to the above led the state of the art in their performance accordingly lower can be dimensioned so that the device according to the invention under economical and economical to manufacture operate.

Regarding the design and arrangement of the electrodes, the device according to the invention several possibilities.

A first embodiment of the device according to the invention thus provides that the electrodes are arcuate in cross section and almost completely the mounting device and thus the pile enclose. This can be achieved, for example, in that the Electrodes of wall sections of the cylindrical reaction chamber are formed, it being necessary that these sections consist of an electrically conductive material and the corresponding Electrode sections through an electrically insulating layer from each other are separated.

A preferred embodiment of the device according to the invention provides that the cylindrical reaction chamber consists of two half-shells, these two half-shells, which are made of a metal, the Form a pair of electrodes. Here are these half shells, as already described above, by an electrically insulating layer connected with each other.

Another possibility is that the reaction chamber from one electrically non-conductive material, for example glass, is made, and the electrodes are arranged inside or outside the reaction chamber  are. In such an embodiment, for example Electrodes also consist of two metallic half-shells, which are along the inner wall or along the outer wall of the reaction chamber extend.

Of course, in the device according to the invention each electrode can also consist of a number of individual electrodes, for example between 4 and 12 , which can be positioned differently within the reaction chamber.

For example, the substrate to be treated before the treatment wrapped on a perforated sleeve, this is another execution form of the device according to the invention that within the perforated Sleeve is arranged at least one further electrode. Here is the associated counter electrode or are the associated counter electrodes arranged outside the pile in the reaction chamber. The for this required counter electrode or the counter electrodes exists or exist then for example from a section of the wall of the reaction chamber, if this wall section consists of metal.

Another embodiment of the device according to the invention provides that the sleeve itself, which is made of metal, has at least one electrode forms. Likewise, the sleeve can be made from two corresponding half-shells are electrically insulated from one another, and thus produce two electrodes receive.

To ensure a particularly good and even flow through the pile ensure sees another embodiment of the invention Device before that the mounting device either the gas supply direction or the gas discharge device is assigned. In case that  the mounting device is provided with the gas supply device the gas discharge device outside the mounting device within the Reaction chamber, preferably in the area of the end faces or the jacket, arranged. In the event that the gas discharge device of the bracket Direction is assigned, the gas supply device is within the Reaction chamber, preferably in the area of the end faces or the jacket, intended. This ensures that the gas from the inside of the pile to the outside or, in the case of the second possibilities described above, from outside flowed inwards. The gas supply device or gas discharge device can be designed for example as a perforated tube then simultaneously serves as a carrier of the winding body.

A particularly suitable embodiment of the device according to the invention provides that the mounting device has a first gas supply device and a first gas discharge device is assigned while the Reaction chamber outside the mounting device, preferably in the area the jacket or the end faces a second gas supply device or has second gas discharge device. Here, during a first Treatment period the gas via the first gas supply device in the Inside of the pile introduced while it was through the second Gas discharge device is suctioned off. This means that during the flows through the pile from the inside out during the first treatment period becomes. During the second treatment period, the gas is replaced by the second Gas supply device directed from the outside to the pile and inside the Haufwerkes deducted by the first gas discharge device, so that the Haufwerk from outside to inside during this second treatment period is flowed through the gas. To achieve this, the first and second are Gas supply and gas discharge devices with a first and a second Provided valve assembly which are switched such that the previously described flow through the pile is achieved. Of course  it is also possible to switch the valve arrangements so that in the the first treatment period, the pile from the outside in and in the second treatment period flows through the pile from the inside out becomes.

Advantageous developments of the method according to the invention and the Device according to the invention are specified in the subclaims.

The device according to the invention is described below using a Embodiment explained in connection with the drawing. Show it:

Fig. 1 is a side schematic sectional view of a first imple mentation form for the treatment of a package and

Fig. 2 is a schematic front view in section of the device shown in Fig. 1.

The generally designated in FIGS. 1 and 2 with 1 is formed as a cylindrical reaction chamber, wherein the cylindrical reaction chamber is made of glass and has an end face arranged loading door 2. Provided within the reaction chamber is a holding device 5 which, in the embodiment shown, holds a pile formed as a winding body 3 . In the embodiment shown, the winding body 3 consists of a yarn spool. Here, the yarn is wound on a cylindrical metal sleeve 4 , which has a plurality of perforations 4 a. The reaction chamber also has two gas supply openings 8 which are arranged diametrically opposite one another and extend through the glass jacket of the reaction chamber. On its opposite end of the loading chamber of the reaction chamber, a gas discharge device 6 is arranged, which is connected to a vacuum pump, not shown.

A vacuum pressure cell 7 is assigned to this gas discharge device 6 . The glass wall 12 of the reaction chamber is enclosed by a half-shell-shaped pair of electrodes 10 , each electrode of the pair of electrodes extending approximately over half the circumference of the glass wall 12 of the reaction chamber. The two electrodes 10 are kept at a distance by an insulator 11 .

The device described above works as follows:
First, the winding body 3 wound onto the perforated sleeve 4 is introduced into the reaction chamber via the loading door 2 and fixed in the position shown in FIGS. 1 and 2 by means of the ceramic holder device 5 .

After the reaction chamber has been closed, it is evacuated to a gas pressure of about 5 Pa by means of the vacuum pump (not shown) via the gas discharge device 6 , this pressure being determined via the measuring device 7 .

Then the gas, preferably oxygen, is continuously supplied by the two gas supply devices 8 , while the gas discharge device 6 constantly evacuates the reaction chamber. By varying the gas supply quantity and the setting of the suction power of the vacuum pump, it is possible to set any pressure curve during the low-temperature plasma treatment, as described above.

A plasma is ignited by applying a high-frequency voltage to the electrode pair 10 , the frequency and power densities being described above. At the end of the treatment, the oxygen supply and the voltage supply to the electrodes are interrupted and the reaction chamber is ventilated via the gas supply lines 8 so that the treated winding body can be removed after the vacuum pump has been switched off.

Claims (25)

1. A method for treating fabrics or fibers, filaments and / or yarns used for the manufacture of fabrics with the aid of a low-temperature plasma, which in the presence of a reactive gas at a pressure between 10 ^-1 Pa and 10³ Pa and Frequency between 1 MHz and 81.36 MHz or 2.54 GHz during a total treatment time of 2 to 30 minutes, characterized in that
before the low-temperature plasma treatment, a pile is made from the flat structures, fibers, filaments or yarns,
one subjects the pile remaining in the device to the low-temperature plasma treatment and
one flows through the pile with a gas during the low-temperature plasma treatment. 2. The method according to claim 1, characterized in that the pressure between 5 Pa and 500 Pa and the frequency between 1 MHz and 81.36 MHz is selected. 3. The method according to claim 1 or 2, characterized in that one the low temperature plasma treatment at a pressure between 50 Pa and 300 Pa, preferably between 70 Pa and 200 Pa. 4. The method according to any one of the preceding claims, characterized in that one with low-temperature plasma treatment during a a pressure between 5 Pa and 20 Pa, preferably between 70 Pa and 120 Pa, and during a subsequent one second treatment period a pressure between 130 Pa and 250 Pa, preferably between 130 Pa and 200 Pa. 5. The method according to claim 4, characterized in that one alternates the first and second treatment period several times repeated. 6. The method according to claim 4 or 5, characterized in that that he at the transition from the first treatment period in the second treatment period and the transition from second treatment period into the first treatment period continuously increases or decreases the pressure.   7. The method according to any one of claims 3 to 6, characterized characterized in that one for the first and second treatment periods, respectively a time between 10 seconds and 160 seconds, preferably between 20 seconds and 60 seconds. 8. The method according to any one of the preceding claims, characterized in that
one sets a pressure at the start of the low-temperature plasma treatment which is lower than the pressure during the low-temperature plasma treatment, and
then the gas is supplied until the required treatment pressure is reached. 9. The method according to any one of the preceding claims, characterized in that one the low temperature plasma treatment at one frequency of 13.56 MHz, 27.12 MHz or 40.68 MHz. 10. The method according to any one of the preceding claims, characterized in that one carries out the low-temperature plasma treatment at a power density between 2 W / dm ³ and 25 W / dm ³ , preferably between 8 W / dm ³ and 14 W / dm ³ . 11. Another embodiment of the method according to claim 1, characterized in that the low-temperature plasma treatment at a frequency of 2.45 GHz, at a pressure of preferably 70 Pa to 120 Pa, and at a power density between 0.1 W / dm³ and 5 W / dm³, preferably between 1.5 W / dm ³ and 3 W / dm ³ . 12. The method according to any one of the preceding claims, characterized in that the reactive gas selected is O ₂ , N ₂ O, CO ₂ , NH ₃ , SO ₂ , SiCl ₄ , CCl ₄ , CF₃Cl, CF ₄ and / or SF ₆ . 13. The method according to any one of the preceding claims, characterized in that the pile by winding the fabrics, filaments or yarns on a perforated sleeve, preferably a perforated metal sleeve. 14. The method according to any one of the preceding claims, characterized in that you alternate the pile from the outside in and from Flows inside with the gas. 15. Device for carrying out the method according to one of the preceding claims, wherein the device comprises a substantially cylindrical reaction chamber, at least two electrodes arranged at a distance from one another, a voltage source for the electrodes, a vacuum source connected to a gas discharge device and a gas supply device, characterized in that that a holding device ( 5 ) for the pile ( 3 ) is provided within the device and the electrodes ( 10 ) are arranged in the reaction chamber such that the pile ( 3 ) extends between the electrodes. 16. The apparatus according to claim 15, characterized in that the electrodes ( 10 ) are arcuate in cross section and almost completely enclose the mounting device ( 5 ). 17. The apparatus according to claim 16, characterized in that
the reaction chamber consists of two metallic half-shells which are connected to one another via an insulation layer, and
the half-shells or regions of the half-shells form the electrodes ( 10 ). 18. Device according to one of claims 15 to 17, characterized in that
the mounting device ( 5 ) comprises a cylindrical perforated sleeve ( 4 ),
at least one electrode is provided within the perforated sleeve and
the metallic wall of the reaction chamber forms the counter electrode. 19. Device according to one of claims 15 to 17, characterized in that
the mounting device ( 5 ) comprises a cylindrically perforated sleeve ( 4 ),
the perforated sleeve ( 4 ) consists of two mutually insulated half-shells and
each half-shell forms an electrode. 20. Device according to one of claims 15 to 19, characterized characterized in that one electrode from a row, preferably between 4 and 12, single electrodes is formed. 21. Device according to one of claims 15 to 20, characterized in that the holding device ( 5 ) is associated with the gas supply device ( 8 ) or the gas discharge device ( 6 ). 22. The apparatus according to claim 21, characterized in that the gas supply device ( 8 ) or the gas discharge device ( 6 ) is designed as a perforated sleeve for receiving the pile. 23. The device according to claim 21, characterized in that
the mounting device (5) comprises a first gas supply means (8) and a first Gasabführeinrichtung (6) are associated and
a second gas supply device and a second gas discharge device are provided outside the mounting device ( 5 ) in the reaction chamber. 24. The device according to claim 23, characterized in that the second gas supply device and the second gas discharge device in the area of the inner wall of the reaction chamber are provided.   25. The apparatus according to claim 23 and 24, characterized in that
the first and second gas supply devices have a first valve arrangement and the first and second gas discharge devices have a second valve arrangement and
the two valve arrangements are provided such that when the first gas supply device and the second gas discharge device are closed, the gas is supplied via the second gas supply device and the first gas discharge device is discharged and vice versa.