DE102019102831A1 - Method and device for the plasma treatment of a material web and method and device for producing a hollow extrudate with a plasma-treated inner surface - Google Patents

Abstract

The invention relates to a method for plasma treatment of a material web (12, 210), in which the material web (12, 210) to be treated is provided in which the cross section of the material web (12, 210) at least in one area of the material web (12, 210 ) is changed in such a way that the material web (12, 210) forms a treatment space (28) which is at least partially closed in cross section, and in which an atmospheric plasma jet (36, 128) is generated and in the treatment space (28) onto the material web (12, 210) ) is directed so that the material web (12, 210) is acted upon by the atmospheric plasma jet (36, 128). The invention also relates to a device (10, 10 ', 10 ", 50) for plasma treatment of a web of material (12, 210). In addition, the invention relates to a method and a device for producing a hollow extrudate (410) with a plasma-treated inner surface.

Description

According to a first aspect, the invention relates to a method and a device for the plasma treatment of a material web. Furthermore, according to a second aspect, the invention relates to a device and a method for producing a hollow extrudate with a plasma-treated inner surface.

From the prior art, for example EP 0 761 415 A1 or EP 1 230 414 A1 , Plasma nozzles and methods are known for changing the surface of a material by means of plasma treatment, for example for hydrophilizing the surface or for plasma coating with the addition of a precursor.

For the plasma treatment of a material web, the width of which cannot be covered by the plasma jet of a single fixed plasma nozzle, it is customary to arrange a plurality of plasma nozzles next to one another transversely to the direction of extent of the material web, in order to treat the material web simultaneously over the entire width while it is being transported under the plasma nozzles becomes. Individual plasma nozzles are also used, which are moved in a pendulum motion across the width of the material web.

However, it has been found that a uniform plasma treatment, in particular a uniform plasma coating of a material web, can hardly be achieved in this way. 1 shows schematically the treatment of a material web 2nd , which extends perpendicular to the plane of the drawing, with several plasma nozzles arranged side by side 4th . Although the material web 2nd this way across the entire width with those from the plasma nozzles 4th escaping plasma rays 6 acted upon. Like that in 1 However, the intensity-location diagram (Ix diagram) shown shows that the intensities of the individual plasma beams add up 6 not to a uniform intensity distribution across the width of the material web 2nd but result in an uneven plasma intensity, with typically maximum intensity directly below the individual plasma nozzle and minimum intensity between the plasma nozzles.

2nd shows another common configuration in which to treat the web 2nd a plasma nozzle 4th in a pendulum motion across the width of the material web 2nd is moved back and forth (double arrow 8th in 2nd ). Because of the turning points on the side edges of the material web 2nd this also leads to uneven treatment, as can be seen in the 2nd shown intensity-location diagram results. In the in 2nd case shown, the plasma intensity is excessive in the edge regions. Depending on the operation and movement of the plasma nozzle 4th a mid rise can also occur. A fairly even treatment can be achieved by using the plasma nozzle 4th over the side edges of the material web 2nd is moved out so that the turning points outside the material web 2nd lying and braking, turning and accelerating the plasma nozzle 4th outside the web 2nd he follows. However, this leads to the plasma nozzle 4th a considerable amount of time outside the area of the material web 2nd is located, so treatment is quite inefficient.

Against this background, the object of the present invention is to provide a method and a device for plasma treatment of a material web with which a more uniform plasma treatment, in particular plasma coating, of the material web can be achieved in a simpler way.

This object is achieved according to the invention by a method for plasma treatment of a material web, in which the material web to be treated is provided, in which the cross-section of the material web is changed at least in one area of the material web such that the material web forms a treatment space which is at least partially closed in cross-section, in which an atmospheric plasma jet is generated and directed at the material web in the treatment room, so that the material web is exposed to the atmospheric plasma jet.

In the method, the material web to be treated can in particular be transported lengthwise through a treatment area and the cross-section of the material web can be changed such that the material web in the treatment area forms the treatment room which is at least partially closed in cross-section. In this way, practically any length of material web can be effectively and uniformly plasma-treated. In the methods described above, the treatment intensity can be set as a function of the transport speed of the material web.

Furthermore, the above-mentioned object is achieved by a device for plasma treatment of a material web, in particular for use in the method described above, with a treatment area, with a transport system that is set up to transport a material web through the treatment area, with a guide device that is set up to change the cross section of a material web transported by the transport system such that the material web in the treatment area forms a treatment room which is at least partially closed in cross section, and with a plasma nozzle for generating an atmospheric plasma jet, wherein the plasma nozzle is set up and arranged to apply an atmospheric plasma jet to a material web transported through the treatment area during operation in the treatment room formed by the material web. The above-mentioned object is further achieved by using the above-described device for plasma treatment of a web-like material, in particular with the previously described method.

It was recognized that a material web can be plasma-treated in a simple and efficient manner and more uniformly by forming a treatment space that is at least partially closed in cross-section by changing the cross-section of the material web in some areas. A reaction space is created with the treatment space so that the wall surrounding the reaction space, i.e. the material web, can be plasma-treated. Even the provision of such a reaction space leads to an equalization of the plasma or any reactions in the plasma, e.g. B. in plasma polymerization, thereby allowing a more uniform plasma treatment, in particular plasma coating of the material web.

The treatment space formed by changing the cross-sectional shape of the material web and at least partially closed in cross-section also enables effective and uniform plasma treatment by means of a rotating plasma nozzle opening positioned in the treatment space. For this purpose, the plasma jet is preferably directed onto the material web by means of a nozzle opening rotating in the treatment room. Since the material web forms the treatment space, which is closed or at least partially closed in cross-section, the plasma jet reaches the material web surface over the entire width in this way, without the need to change directions in the nozzle opening rotation, which could otherwise lead to an uneven plasma treatment. In a corresponding preferred embodiment of the device, the plasma nozzle has a nozzle opening from which the plasma jet emerges during operation, the nozzle opening being arranged in such a way that it is positioned during operation in the treatment space formed by the material web, and the nozzle opening is set up for this to rotate in operation.

The material web to be treated can be, for example, a material web made of metal, plastic, rubber, textile material, fleece, fiber-reinforced plastic, for example carbon fiber (CFRP) or glass fiber reinforced plastic (GFK), or a combination thereof. Basically, there are no limits to the structure and materials of the material web; however, the material web should be such that its cross section can be changed in such a way as to form an at least partially closed treatment room.

The material web can in particular be made available as a flat material web, the uniform plasma treatment of which is difficult in a conventional manner. The material web is preferably a flat, continuous web (web material).

The cross section of the material web can be changed in particular by bending the side edges of the material web around or towards one another, so that the material web forms the treatment space which is at least partially closed in cross section.

The cross section of the material web can for example be changed in some areas to a (partially closed in the circumferential direction) C-shaped cross section or also to an (completely closed in the circumferential direction) O-shaped cross section. In principle, other cross sections are also conceivable.

If, for example, the material web is initially essentially flat and accordingly has a flat cross-sectional shape, the cross-section of the material web can be formed into a C-shaped or O-shaped cross-section by bending the side edges up and down, through which the cross-section is partially or completely closed treatment room is formed.

A similar principle is also known from another technical area, namely of tube belt conveyors, in which the cross section of a running conveyor belt is changed to a tube after a conveyed item has been fed in, so that the conveyed item is safe and e.g. can be transported dust-free.

The treatment room must be in the circumferential direction, i.e. H. in cross section, not be completely closed. Furthermore, the material web does not have to extend over the entire cross section of the treatment room. Instead, the treatment room can, for example, also be open on a peripheral side, for example upwards, or closed on a peripheral side by another surface, for example a guide surface.

The treatment room is particularly open in the direction of the longitudinal extent of the material web. In this way, for example, one of these two open sides can be opened Introduce or position the plasma nozzle or a nozzle head of a plasma nozzle with a nozzle opening in the treatment room.

Various embodiments of the method and the device are described below, the individual embodiments each independently of one another applying both to the method and to the device. In addition, the individual embodiments can be combined with one another.

In a first embodiment, a precursor is introduced into the plasma jet. The precursor is activated, fragmented and / or excited to a chemical reaction by the plasma jet, so that a layer forms on the material web. Since the plasma jet and thus also the precursor in the plasma jet act very uniformly on the material web, a very uniform plasma coating of the material web can also be achieved with this method. The thickness of the deposited layer can be controlled by the amount of precursor and / or by the speed at which the material web is transported through the treatment area or relative to the nozzle opening.

For example, an organic molecule can be used as a precursor, for example an organic molecule that polymerizes under the action of the plasma jet and thereby forms a plasma-polymerized layer on the surface of the material web. In addition to organic precursors, inorganic precursors can also be used.

By using a precursor, in particular a uniform carbon layer can be deposited on the material web, which has proven to be particularly difficult with the previous plasma coating methods. For this purpose, an aliphatic precursor, for example methane or acetylene, or else an aromatic precursor is preferably used. If a gaseous precursor, for example methane or acetylene, is used, it can simultaneously be used as the working gas for a plasma nozzle for generating the plasma jet.

Instead of introducing the precursor into the plasma jet, the precursor can also be applied directly to the material web, in particular before or while the plasma jet is being swept over it.

In a further embodiment, a protective gas is introduced into the treatment room. The protective gas can, for example, be nitrogen, an inert gas or mixtures thereof. In this way, the plasma treatment, in particular plasma coating, can be carried out under protective gas in order, for example, to prevent oxidation of a precursor. Since the material web forms the treatment room, which is essentially closed in cross section, complex design structures for maintaining the protective gas atmosphere are unnecessary.

In one embodiment, the cross section of the material web is changed such that the material web forms a treatment room with an essentially circular cross section. Furthermore, the axis of rotation of the nozzle opening is preferably positioned in the middle of the essentially circular cross section. In this way, a particularly uniform treatment of the material web can be achieved since the distance between the nozzle opening and the material web exposed to the plasma jet remains essentially constant when the nozzle opening rotates.

In a further embodiment, the material web to be treated is provided as a roll product on a roll and unwound from the roll. After exposure to the plasma jet, the material web is preferably rewound on a roll. In a corresponding embodiment, the device has a rolling device for rolling a material web from a roll and / or a rolling device for rolling a material web onto a roll. In this way, long material webs can be processed to save space.

In a further embodiment, the cross section of the material web is changed after the application of the plasma jet to the material web, in particular to a flat cross-sectional shape. In particular, the cross section of the material web can be changed back to the original shape. If, for example, the material web to be treated is provided on a roll as a roll, unwound from the roll and the cross-section is changed in such a way that it forms the treatment room before it is exposed to the plasma jet, it can, for example, return to the treatment area after exposure to the plasma jet brought flat cross-sectional shape and rewound on a roll.

In a further embodiment, the treatment space, which is at least partially closed in cross section, is formed by a plurality of material webs or different sections of the same material web. For example, it is conceivable that two material webs are treated at the same time, the cross sections of the material webs being changed such that the material webs together form the treatment room, for example a first one Material web the lower part of the treatment room and a second material web the upper part of the treatment room.

Furthermore, it is conceivable that the treatment room is formed by different sections of the same material web, for example by guiding a material web in such a way that a section of the material web with an inner front face a first part of the treatment room and another section of the material web with an inner rear face a second section of the treatment room. In this way, the material web can be evenly plasma-treated on both sides, in particular plasma-coated.

In a further embodiment, the material web to be treated consists of unconnected filaments arranged next to one another. It was recognized that the method described above can not only be used to plasma-treat coherent material webs, but also a plurality of filaments, such as threads, yarns or wires, in that the filaments, for example after unwinding the individual filaments from a respective spool, be arranged side by side such that they form a material web.

In a further embodiment, the guide device comprises a plurality of guide rollers which are arranged in such a way that the cross section of a material web guided over the guide rollers is changed such that the material web in the treatment area forms the treatment space which is at least partially closed in cross section. The use of guide rollers to change the cross section of the material web is particularly suitable for material webs with higher rigidity, for example rubber or plastic webs. The cross section of such material webs can be changed in a simple manner and with simple means by means of the guide rollers.

In a further embodiment, the guide device has an inlet guide surface which is shaped in such a way that the cross section of a material web guided over the inlet guide surface is changed before passing through the treatment area in such a way that the material web forms the treatment space which is at least partially closed in cross section. With such an inlet guide surface, the material web is supported flatly when the cross-section changes and can therefore be brought into the desired shape without causing wrinkles.

The inlet guide surface can be funnel-shaped at least in sections. Due to the continuously decreasing cross-section of the funnel, the material web is continuously and gently formed until it forms the treatment room, which is at least partially closed in cross-section.

In a further embodiment, the guide device is also set up to change the cross section of a material web transported by the transport system after passing through the treatment area, in particular to a substantially flat cross-sectional shape. In this way, the material web can, for example, be brought back into its original shape after the treatment, so that it can be processed more easily, in particular wound up again.

In a further embodiment, the guide device has an outlet guide surface which is shaped in such a way that the cross section of a material web guided over the outlet guide surface is changed after passing through the treatment area, in particular to a substantially flat cross-sectional shape. The guide surface can in particular be funnel-shaped in sections. In this way, the material web is brought back to its original shape gently and evenly without wrinkling.

For example, the guide device can have a double funnel, with a funnel that narrows in cross section in front and a funnel that widens in cross section behind the treatment area.

In a further embodiment, the guide device in the treatment area has a treatment guide surface for guiding a material web transported through the treatment area. In this way, the material web is supported flat in the treatment area, so that the cross-sectional shape of the material web remains within the treatment area and a uniform treatment of the material web is ensured. If the cross-section of the material web in the treatment area is not completely closed, the treatment guide surface can also close the missing part to a closed cross-section, so that the treatment space is given a completely closed cross-section by the treatment guide surface, whereby a further homogenization of the plasma treatment is achieved.

In a further embodiment, the guide device has a coolable or heatable guide surface for guiding the material web. In particular, the inlet, the outlet and / or the treatment guide surface can be cooled or heated. By heating the Plasma treatment can be intensified. By cooling, thermal loads emanating from the plasma treatment can be dissipated from the material web, so that in particular heat-sensitive material webs can be treated better.

In a further embodiment, the guide device has a guide surface with a plurality of openings and a flow device for extracting or blowing out air through the openings. In particular, the inlet, the outlet and / or the treatment guide surface can have corresponding openings. By sucking air through the openings it can be achieved that the material web is sucked onto the guide surface, so that wrinkles are prevented. Furthermore, sucking the material web onto the guide surface has the advantage that the plasma jet can penetrate deeper into the material web. For example, when treating a material web made of nonwoven, it was found that the plasma jet can penetrate the nonwoven better if a suction device is provided on the opposite side of the material web. The blowing out of air through the openings leads to the formation of an air film between the guide surface and the material web and can in this way reduce the friction between the material web and the guide surface, so that better sliding of the material web on the guide surface is achieved.

In a further embodiment, the device has a housing surrounding the treatment area with an inlet opening for running a material web into the treatment area and with an outlet opening for running the material web out of the treatment area. In this way, the treatment area can be shielded from the environment, so that a plasma treatment can be carried out regardless of the environmental conditions. Furthermore, a treatment area surrounded by such a housing can be easily integrated in-line in a larger system.

Another object of the present invention is to plasma-treat the inner surface of a hollow extrudate in a simple and uniform manner, in particular plasma-coating.

According to a second aspect of the present invention, this object is achieved according to the invention by a device for producing a hollow extrudate with a plasma-treated inner surface with an extrusion device, which is set up to extrude a hollow extrudate from an extrusion nozzle, and with a plasma nozzle for generating an atmospheric plasma jet, wherein the plasma nozzle is arranged in the region of the extrusion nozzle in such a way that an internal surface of a hollow extrudate extruded from the extrusion nozzle during operation is acted upon by the plasma jet emerging from the plasma nozzle.

Furthermore, the above-mentioned object is achieved by a method for producing a hollow extrudate with a plasma-treated inner surface, in which a hollow extrudate is produced by extruding the hollow extrudate from an extrusion nozzle, in which an atmospheric plasma jet is generated, and in which an inner surface of the hollow extrudate in the region the extrusion nozzle is subjected to the plasma jet.

It was found that hollow extrudates, such as hoses or pipes, can be plasma-treated in this way directly during manufacture, so that, for example, the surface properties of the inner surface of the hollow extrudate can be changed or the inner surface can be coated by means of plasma coating. The hollow extrudate can be, for example, a hose or a tube, in particular made of plastic. Furthermore, the hollow extrudate can also be a film tube, in particular in blown film production.

The extrusion device in particular comprises an extruder with which a melt, in particular liquid plastic, is extruded through the extrusion nozzle during operation. The extrusion nozzle preferably has a closed contour, for example an annular contour, and therefore leads to the extrusion of a hollow extrudate with a cavity in the middle. The plasma nozzle can in particular be arranged in the region of the extrusion nozzle in such a way that the nozzle opening of the plasma nozzle is surrounded by the closed, in particular annular, contour of the extrusion nozzle.

The plasma nozzle preferably has a nozzle opening which is directed towards the inner surface of the extrudate emerging from the extrusion nozzle during operation and rotates about the longitudinal axis of extension or about an axis parallel to it. In a corresponding embodiment, the plasma jet emerges from a rotating nozzle opening of a plasma nozzle arranged in the region of the extrusion nozzle. In this way, the inner surface of the hollow extrudate is evenly plasma-treated, in particular coated.

Further features and advantages of the previously described methods and devices result from the following description of exemplary embodiments, reference being made to the attached drawing. In the description of the exemplary embodiments, functionally corresponding components are different Embodiments with the same reference numerals. However, the components provided with the same reference numbers are not necessarily identical, but can differ from one another in particular in size, shape and arrangement in the individual exemplary embodiments.

• 1 ein Verfahren zur Plasmabehandlung einer Materialbahn aus dem Stand der Technik,
• 2 ein weiteres Verfahren zur Behandlung einer Materialbahn aus dem Stand der Technik,
• 3a-d ein Ausführungsbeispiel des Verfahrens und der Vorrichtung zur Plasmabehandlung einer Materialbahn,
• 4a-d ein weiteres Ausführungsbeispiel der Vorrichtung und des Verfahrens zur Plasmabehandlung einer Materialbahn,
• 5 eine Plasmadüse zur Erzeugung eines Plasmastrahls,
• 6 ein Ausführungsbeispiel für den Einsatz der Plasmadüse aus 5 in einer Vorrichtung zur Plasmabehandlung einer Materialbahn,
• 7 ein weiteres Ausführungsbeispiel einer Plasmadüse,
• 8 ein Ausführungsbeispiel für den Einsatz der Plasmadüse aus 7 in einer Vorrichtung zur Plasmabehandlung einer Materialbahn,
• 9 eine weitere Plasmadüse zur Erzeugung eines Plasmastrahls,
• 10 ein Ausführungsbeispiel des Einsatzes des Plasmadüse aus 9 in einer Vorrichtung zur Plasmabehandlung einer Materialbahn,
• 11a-c ein weiteres Ausführungsbeispiel des Verfahrens zur Plasmabehandlung einer Materialbahn, und
• 12 ein Ausführungsbeispiel des Verfahrens und der Vorrichtung zur Herstellung eines Hohlextrudats mit plasmabehandelter Innenfläche gemäß dem zweiten Aspekt der vorliegenden Offenbarung.

The drawing shows:

• 1 a method for plasma treatment of a material web from the prior art,
• 2nd another method for treating a material web from the prior art,
• 3a-d an embodiment of the method and the device for plasma treatment of a material web,
• 4a-d a further embodiment of the device and the method for plasma treatment of a material web,
• 5 a plasma nozzle for generating a plasma jet,
• 6 an embodiment for the use of the plasma nozzle 5 in a device for the plasma treatment of a material web,
• 7 another embodiment of a plasma nozzle,
• 8th an embodiment for the use of the plasma nozzle 7 in a device for the plasma treatment of a material web,
• 9 another plasma nozzle for generating a plasma jet,
• 10th an embodiment of the use of the plasma nozzle 9 in a device for the plasma treatment of a material web,
• 11a-c a further embodiment of the method for plasma treatment of a material web, and
• 12th an embodiment of the method and the device for producing a hollow extrudate with plasma-treated inner surface according to the second aspect of the present disclosure.

The 3a-d show a first embodiment of the device and the method for plasma treatment of a material web. 3a shows a schematic perspective view, 3b-d show different sectional views according to the in 3a with cutting planes designated IIIb, IIIc or IIId.

The device 10th for plasma treatment of a flat material web 12th includes a rolling device 14 and a retractor 16 so that the web-shaped material web 12th from the unwinding device 14 now and then on the retractor 16 can be rolled up. The unwinding device 14 and the retractor 16 are driven and thus form a transport system 18th with which the material web 12th through a treatment area 20 the device 10th can be transported.

In front of the treatment area 20 is an inlet guide surface 22 provided in the form of a funnel. Behind the treatment area 20 is an outlet guide surface 24th provided in the form of a (inverted) funnel. The inlet guide surface 22 and the outlet guide surface 24th are through a tubular treatment guide surface 26 connected with each other. The guide surfaces 22 , 24th and 26 together form the management facility 27 .

The material web is in operation 12th from the unwinding device 14 unrolled, runs through the funnel-shaped inlet guide surface 22 , through the treatment area 20 and through the funnel-shaped outlet guide surface 24th to the retractor 16 , on which it is rolled up again.

The web of material 12th initially has a flat cross-sectional shape when rolling, as in 3b is shown schematically. Through the funnel-shaped inlet guide surface 22 is the cross section of the material web as in the 3a-d shown changed so that the material web in the treatment area 20 within the treatment guidance area 26 a treatment room which is at least partially closed in cross section, in the present example even completely closed 28 forms (s. 3d ). With the device 10th becomes the web of material 12th for this bent so that the side edges 30a-b in the treatment area 20 almost collide and the web of material 12th has a substantially O-shaped cross section. The one from the material web 12th formed treatment room 28 accordingly has a substantially circular cross section.

In the treatment area 20 is a plasma source 32 arranged with a nozzle opening 34 , out of which a plasma jet during operation 36 emerges laterally in such a way that the plasma jet 36 on the inner surface of the material web 12th reached. The plasma nozzle 32 is set up to open the nozzle 34 rotates in the circumferential direction (arrows 38 ), so that the plasma jet over the entire circumference of the circular cross section of the material web 12th and thus evenly over the entire width of the material web 12th acts. In this way, a uniform plasma treatment of the material web 12th reached. By introducing a precursor into the plasma jet 36 For example, a uniform plasma coating of the material web 12th can be achieved.

After passing through the treatment area 20 becomes the cross section of the material web 12th through the outlet guide surface 24th brought back to its original flat shape and then the material web 12th with the retractor 16 wound up.

The 4a-d show a further embodiment of the method and the device for plasma treatment of a material web.

The device 50 differs from the device 10th out 3a that instead of the inlet guide surface 22 , the treatment guide surface 26 and the outlet guide surface 24th leadership roles each 52 are provided, the cross section of the material web 12th change such that the material web 12th a treatment room which is at least partially closed in cross section 28 forms. How 4b (Sectional view showing the elements behind the cutting plane) shows the cross section of the material web 12th through the leadership roles 52 deformed from a flat cross-section to a substantially C-shaped cross-section, so that the treatment room 28 is not completely closed in the circumferential direction (see 4c ); Of course, it is also conceivable that the cross section of the material web 12th is deformed into an O-shaped cross-section, so that there is a closed treatment area in cross-section 28 results.

Even with this device 50 is done by changing the cross section of the web of material 12th so this is a treatment room 28 forms, and by the plasma treatment with the plasma nozzle 32 inside the treatment room 28 reached that web of material 12th can be plasma-treated uniformly over the entire width, in particular plasma-coated.

5 shows an embodiment of a plasma nozzle that can be used in the method or in the device for plasma treatment.

The plasma nozzle 62 has a tubular housing 64 in the form of a nozzle tube made of metal. The nozzle pipe 64 has a conical taper at one end 66 on which an interchangeable nozzle head 68 is mounted, the outlet of which is a nozzle opening 70 forms from the plasma jet during operation 36 exit.

At that of the nozzle opening 70 the nozzle tube is at the opposite end 64 to a working gas supply line 74 connected. The working gas supply 74 is connected to a pressurized work source (not shown) with variable throughput. In operation there is a working gas 76 from the working gas source through the working gas supply line 74 into the nozzle tube 64 initiated.

In the nozzle pipe 64 is still a swirl device 78 with a ring of obliquely drilled holes in the circumferential direction 80 provided by which in operation in the nozzle tube 64 introduced working gas 76 is twisted.

The downstream part of the nozzle tube 64 is therefore from the working gas 76 in the form of a vortex 82 flows through, its core on the longitudinal axis of the nozzle tube 64 runs.

In the nozzle pipe 64 is still an inner electrode in the middle 84 arranged, which is in the nozzle tube 64 coaxially in the direction of the nozzle opening 70 extends. The inner electrode 84 is electrical with the swirl device 78 connected. The swirl device 78 is through a ceramic tube 86 electrically against the nozzle tube 64 isolated. Via a high-frequency line 88 is attached to the inner electrode 84 a high frequency high voltage applied by a transformer 90 is produced. The nozzle pipe 64 is via an earth wire 92 grounded. The applied voltage causes a high-frequency discharge in the form of an arc 94 between the inner electrode 84 and the nozzle tube 64 generated. This area in the nozzle tube 64 thus represents a discharge space of the plasma nozzle 62 represents.

The terms “arc”, “arc discharge” or “arc-like discharge” are used here as a phenomenological description of the discharge, since the discharge occurs in the form of an arc. The term “arc” is also used elsewhere as a form of discharge for direct voltage discharges with essentially constant voltage values. In the present case, however, there is a high-frequency discharge in the form of an arc, that is to say a high-frequency, arc-like discharge.

Due to the swirling flow of the working gas, this arc will 94 in the vortex core in the area of the axis of the nozzle tube 64 channeled so that it is only in the area of rejuvenation 66 to the wall of the nozzle pipe 64 branches.

The working gas 76 , in the area of the vortex core and thus in the immediate vicinity of the arc 94 rotates at high flow speed, comes with the arc 94 in intimate contact and is thereby partially converted into the plasma state, so that an atmospheric plasma jet 36 through the nozzle opening 70 from the plasma nozzle 62 exit.

6 now shows an example of the use of the plasma nozzle 62 out 5 in a contraption 10 ' for plasma treatment of a material web, which in principle is like the device 10th out 3rd is constructed. 6 shows a cross section of the device 10 ' according to the cross section in 3d in the treatment area 20 .

The device 10 ' differs from the device 10th that as the plasma nozzle, the plasma nozzle 62 out 5 in the treatment area 20 within the treatment guidance area 26 is arranged. The plasma nozzle 62 is about the central axis 100 the treatment guide area 26 rotationally driven (arrow 102 ) so that the plasma nozzle around the axis 100 rotates and that from the nozzle opening 70 the plasma nozzle 62 escaping plasma jet 36 in operation across the entire width of the material web 12th is led in 6 has an O-shaped cross section.

The treatment guide area 26 is in 6 through a pipe 104 formed that a variety of openings 106 has, by means of a flow device, such as a fan 108 , Gas, especially air, from inside the tube 104 is suctioned off. In this way, the web of material 12th to the leadership area 26 pulled without wrinkling. Furthermore, gas has to be extracted through the openings 106 the advantage that when treating a material web 12th from fleece the plasma jet 36 penetrates better through the entire fleece, so that a more intensive plasma treatment of the entire fleece of the material web 12th can be achieved.

7 shows the nozzle head 68 ' an alternative plasma nozzle 62 ' . Except for the other nozzle head 68 ' the structure and mode of operation of the plasma nozzle differ 62 ' not from the plasma nozzle 62 out 5 . The nozzle head 68 ' is with the camp 110 rotatable in the nozzle tube 64 stored and has an inclined nozzle opening to the side 70 ' from which the plasma jet 36 at an oblique angle to the axis of the plasma nozzle 62 ' exit. The rotatable nozzle head 68 ' can be driven in rotation, for example by a provided compressed air supply 112 pointing to one on the nozzle head 68 ' provided fan 114 is directed. Alternatively, the nozzle opening 70 ' be aligned so that the direction of the plasma jet 36 an azimuthal component to the axis of rotation of the nozzle head 68 ' has so that the nozzle head 68 ' by the recoil of the plasma jet 36 is driven.

8th shows an example of the use of the plasma nozzle 62 ' out 7 in a device for the plasma treatment of a material web. The device 10 " has a structure similar to that of the device 10th out 3rd or. 10 ' out 6 .

The device 10 " differs from the device 10 ' out 6 that instead of the plasma nozzle 62 the plasma nozzle 62 ' out 7 is used, the longitudinal axis of the plasma nozzle running perpendicular to the plane of the drawing. Because of the diagonal outward opening of the nozzle 70 ' gets out of the nozzle opening 70 ' escaping plasma jet 36 on the material web 12th so that it is plasma treated. Because of the rotation of the nozzle head 68 ' also rotates the direction of propagation of the plasma jet 36 so the web of material 12th across the entire circumference of the treatment room and thus across the entire width evenly through the plasma jet 36 is swept over, so that a uniform surface treatment of the material web 12th he follows.

The pipe 104 again has a plurality of openings 106 on. Different from the device 10 ' out 6 blows the intended flow device 108 but now a gas, for example air, through the openings 106 into the pipe 104 inside. This creates between the guide surface 22 and the material web 12th an air film so that the friction of the web of material to the pipe 104 is reduced. In this way, the material web 12th with less force through the treatment area 20 be transported.

9 shows the nozzle head 68 " another alternative plasma nozzle 62 " . Except for the other nozzle head 68 " the structure and mode of operation of the plasma nozzle differ 62 " not from the plasma nozzle 62 out 5 . The nozzle head 68 " is designed as a plasma distributor head and has a channel 124 on, in its canal wall along the canal 124 a variety of nozzle openings 126 are provided through which one from the nozzle tube 64 in the channel 124 guided plasma jet 36 can leak. In this way, a single plasma jet 36 a broad plasma curtain on partial plasma beams 128 generated so that a larger treatment range is achieved. The distribution of the plasma jet 36 into several plasma beams 128 also has the effect that the intensity of the plasma beam 36 is distributed over a larger area, so that the plasma output per area is reduced and particularly sensitive materials can be treated well. This configuration has proven particularly advantageous, for example, for treating textile materials or nonwovens. Such is a plasma nozzle 62 " suitable for the treatment of thin foils, for example plastic foils.

10th shows an example of the use of the plasma nozzle 62 " out 9 in a device for the plasma treatment of a material web. The device 10 '"has a similar structure to the device 10th out 3rd or. 10 ' out 6 .

The device 10 '"thereby differs from the device 10 ' out 6 that instead of the plasma nozzle 62 one or even two plasma nozzles in the present example 62 " out 9 be used. The nozzle heads 68 " of the two plasma nozzles 62 " are arranged to each other in such a way that the plasma partial beams 128 exit in the opposite direction. The plasma nozzles 62 " are around the central axis 100 rotationally driven (arrow 102 ) so that out of the nozzle heads 68 " emerging plasma beams 128 the treatment room wall over the entire circumference and thus the material web 12th Paint over the entire width and treat evenly with plasma.

Different from the devices 10 ' and 10 " from the 6 and 8th points the pipe 104 ' that the treatment guide surface 24th forms no openings in the device 10 '". Instead, is around the tube 104 ' a heat exchanger duct 132 arranged by the warm or cold heat exchange fluid 134 can be pumped to the pipe 104 ' and with it the surface 22 to heat or cool.

By cooling the surface 22 can heat energy of the plasma rays 128 are removed so that even particularly sensitive material webs can be treated. Heating the pipe 104 ' can intensify the plasma treatment.

11a-c show an alternative embodiment of the inventive method and an inventive device.

The device 200 has a structure similar to that of the device 10th , being instead of the unwinding device 14 and the retractor 16 a variety of unwinding spools 202 and reels 204 are provided. In operation, the individual coils 202 one filament each, for example a thread 206 handled. The individual unwound threads 206 are sent to an alignment facility 208 , which can have guide rollers, for example, arranged side by side in such a way that a web-shaped material 210 from incoherently arranged threads. This web of material 210 can then like the web of material 12th with the device 10th through the treatment area 20 guided and treated there, so that the individual threads 206 Pretreat at the same time. Then the material web 210 at a separation device 212 , which can also have different roles, for example, again in individual threads 206 split up so that on a respective spool 204 can be wound up.

12th shows an embodiment of the device and the method for producing a hollow extrudate with a plasma-treated inner surface according to the second aspect of the present disclosure.

The device 400 has an extrusion device 402 with an extruder 404 for the extrusion of plastic and an annular extrusion nozzle 406 through which the melt operates 408 as a tubular hollow extrudate 410 is extruded. In the area of the extrusion die 406 is a plasma nozzle 412 with a rotating nozzle head 414 arranged, the nozzle head having a laterally emerging nozzle opening 416 has a plasma jet during operation 418 emerges laterally and thereby onto the inner surface of the through the extrusion nozzle 406 extruded hollow extrudate. In this way the hollow extrudate 410 , for example a tube or a hose, are plasma-treated, in particular plasma-coated, directly from the inside during manufacture. For the plasma coating, in particular a precursor can be placed in the plasma jet 418 or in the working gas of the plasma nozzle 412 be initiated. The plasma nozzle 412 can in particular like the plasma nozzle 62 ' out 7 be trained. Alternatively, configurations corresponding to the plasma nozzle are also possible 62 ' or. 62 " out 5 or. 9 conceivable.

Around the extrusion die 406 Blowers can be provided to the hollow extrudate 410 from the outside with gas, especially air 420 to apply and to cool the melt faster.

The extrusion device 402 can also be set up for blown film extrusion instead of the production of tubes or hoses. In this case, in particular, also within the ring-shaped extrusion die 406 a blowing device for blowing the hollow extrudate 410 be provided from the inside. Due to the plasma nozzle provided in the interior 412 such a blowing device may also be dispensed with if there is sufficient air with the plasma jet 418 inside the hollow extrudate 410 reached.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 0761415 A1 [0002]
• EP 1230414 A1 [0002]

Claims (18)

Method for plasma treatment of a material web (12, 210), in particular using a device (10, 10 ', 10 ", 10"', 50) according to one of the Claims 7 to 14 , - in which the material web (12, 210) to be treated is provided, - in which the cross section of the material web (12, 210) is changed at least in a region of the material web (12, 210) such that the material web (12, 210 ) forms a treatment room (28) which is at least partially closed in cross section, - in which an atmospheric plasma jet (36, 128) is generated and directed in the treatment room (28) onto the material web (12, 210), so that the material web (12, 210 ) with the atmospheric plasma jet (36, 128). Procedure according to Claim 1 , characterized in that the material web (12, 210) to be treated is transported lengthwise through a treatment area (20) and in that the cross section of the material web (12, 210) is changed such that the material web (12, 210) is in the treatment area (20) forms the treatment room (28) which is at least partially closed in cross section. Procedure according to Claim 1 or 2nd , characterized in that the plasma jet (36, 128) is directed onto the material web (12, 210) by means of a nozzle opening (34, 70, 70 ') rotating in the treatment room (28). Procedure according to one of the Claims 1 to 3rd , characterized in that a precursor is introduced into the plasma jet (36, 128) or is applied to the material web (12, 210). Procedure according to one of the Claims 1 to 4th , characterized in that the treatment space (28) which is at least partially closed in cross section is formed by a plurality of material webs (12, 210) or different sections of the same material web (12, 210). Procedure according to one of the Claims 1 to 5 , characterized in that the material web (210) to be treated consists of unconnected filaments (206) arranged side by side. Device (10, 10 ', 10 ", 10"', 50) for plasma treatment of a material web (12, 210), in particular for use in a method according to one of the Claims 1 to 6 , - with a treatment area (20), - with a transport system (18) which is set up to transport a material web (12, 210) through the treatment area (20), - with a guide device (27) which is set up for this purpose to change the cross section of a material web (12, 210) transported by the transport system (18) such that the material web (12, 210) in the treatment area (20) forms a treatment space (28) which is at least partially closed in cross section, and - with a plasma nozzle (32, 62, 62 ', 62 ") for generating an atmospheric plasma jet (36, 128), - the plasma nozzle (32, 62, 62', 62") being set up and arranged to operate one by the Treatment area (20) transported material web (12, 210) in the treatment room (28) formed by the material web (12, 210) with an atmospheric plasma beam (36, 128). Device after Claim 7 , characterized in that the plasma nozzle (32, 62, 62 ', 62 ") has a nozzle opening (34, 70, 70', 126) from which the plasma jet (36, 128) emerges during operation, the nozzle opening (34 , 70, 70 ', 126) is arranged such that during operation it is positioned in the treatment room (28) formed by the material web (12, 210), and the nozzle opening (34, 70, 70', 126) is set up for this purpose is to rotate in operation. Device after Claim 7 or 8th , characterized in that the guide device (27) has an inlet guide surface (22) which is shaped such that the cross section of a material web (12, 210) guided over the inlet guide surface (22) before passing through the treatment area (20) is changed such that the material web (12, 210) forms the treatment room (28) which is at least partially closed in cross section. Device after Claim 9 , characterized in that the inlet guide surface (22) is funnel-shaped at least in sections. Device according to one of the Claims 7 to 10th characterized in that the guide device (27) has an outlet guide surface (24) which is shaped such that the cross section of a material web (12, 210) guided over the outlet guide surface (24) after passing through the treatment area (20) is changed, in particular in a substantially flat cross-sectional shape. Device according to one of the Claims 7 to 11 , characterized in that the guide device (27) in the treatment area (20) has a treatment guide surface (26) for guiding a material web (12, 210) transported through the treatment area (20). Device according to one of the Claims 7 to 12th , characterized in that the guide device (27) is a cooled or heated Has guide surface (22, 24, 26) for guiding the material web (12, 210). Device according to one of the Claims 7 to 13 , characterized in that the guide device (27) has a guide surface (22, 24, 26) with a plurality of openings (106) and a flow device for extracting or blowing out air through the openings (106). Use of a device (10, 10 ', 10 ", 50) according to one of the Claims 7 to 14 for plasma treatment of a web-like material (12, 210). Device (400) for producing a hollow extrudate with a plasma-treated inner surface, in particular for carrying out a method according to Claim 17 or 18th , - with an extrusion device (402) which is set up to extrude a hollow extrudate (410) from an extrusion nozzle (406), and - with a plasma nozzle (412) for generating an atmospheric plasma jet (418), - the plasma nozzle ( 412) is arranged in the area of the extrusion nozzle (406) such that an internal surface of a hollow extrudate (410) extruded from the extrusion nozzle (406) during operation is acted upon by the plasma jet (418) emerging from the plasma nozzle (412). Method for producing a hollow extrudate (410) with a plasma-treated inner surface, in particular using a device according to Claim 16 , - in which a hollow extrudate (410) is produced by extruding the hollow extrudate (410) from an extrusion nozzle (406), - in which an atmospheric plasma jet (418) is generated and - in which an inner surface of the hollow extrudate (410) in Area of the extrusion nozzle (406) with which the plasma jet (418) is applied. Procedure according to Claim 17 characterized in that the plasma jet (418) emerges from a rotating nozzle opening (416) of a plasma nozzle (412) arranged in the region of the extrusion nozzle (406).

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