The invention relates to an apparatus for producing monofilaments or ribbons as defined in the preamble of claim 1.
A generic apparatus is disclosed, for example, in DE 10 2005 049 163 A1.
The apparatus disclosed comprises an extrusion device and several treatment devices to produce a plurality of ribbons from an extruded film. In order to prevent the group of ribbons from sticking to the heating surface of the heating device when being guided through the heating device as a result of a breakage of the individual ribbons, the heating surface is equipped with a nonstick coating.
Furthermore, it is well-known that such nonstick coatings, for example, those made of Teflon, form a particularly advantageous low-friction contact surface for guiding monofilaments or ribbons. In particular, it is desirable to use low-friction guide elements in the production of turf yarn that exhibits a relatively high degree of elasticity. Consequently, it is also well-known to use guide elements having a low-friction coating in the apparatus disclosed. However, it has been observed, during operation, that such low-friction coatings are not very wear-resistant and they therefore necessitate a frequent replacement of such guide elements.
It is therefore an object of the present invention to further develop a generic apparatus for producing monofilaments or ribbons such that the surfaces of the guide elements are both low-friction and wear-resistant.
According to the invention, this object is achieved in that the contact surface has a multiple coating comprising several coating materials, the multiple coating is formed by several single coatings, each with a different layer thickness, and the single coatings are formed in a sandwich-like manner on the contact surface.
Advantageous embodiments of the invention are defined by the features and combinations of features of the subordinate claims.
The invention has the special advantage that the property of the contact surface is characterized by several coating materials so that different surface properties are operative in combined form on the contact surface. In particular, the running characteristics desired for guiding very elastic monofilaments or ribbons can be retained as a result of the sandwich-like arrangement of the single coatings.
In order to maintain the characteristic properties of the coating materials over the longest possible service life, a preferred embodiment of the invention is developed. In this development, the single coatings of the multiple coating each have a minimum layer thickness of >20 μm.
Hereby, it is particularly advantageous if an inner single coating has a layer thickness that is greater than that of an outer single coating by a factor of 5. Thus it is also possible to homogenize and protect rougher surface textures of the base body by means of a first single coating.
This division of the layer thicknesses has proved useful particularly in an envelopment of the invention in which the coating material of the outer single coating is formed by a sliding material for reducing friction, and the coating material of the inner single coating is formed by a protective material for minimizing wear.
The use of a ceramic as the protective material and the use of a plastic as the sliding material have proved particularly useful for this purpose. In particular, PTFE [polytetrafluoroethylene] is well-suited for use as the plastic in order to ensure very low-friction guidance of the monofilaments or ribbons.
For producing the maximum possible monofilaments or ribbons side by side, a preferred embodiment of the invention is developed in which the contact surface is formed on the guide element over a length of >1,000 mm thereof. Thus it is possible to realize large working widths in order to guide a plurality of monofilaments or ribbons.
In order to enable a uniform cooling or heating of each monofilament or ribbon, for example during the thermal treatment, it is necessary to spread the ribbons cut out from a film or the freshly extruded monofilaments. For this purpose, the guide element is preferably formed by a grooved rod that comprises a guide slot for each monofilament or ribbon and that forms the contact surface. Such types of grooved rods are preferably cylindrical in shape and they comprise circumferential guide slots that are provided with the multiple coating around the entire circumference and over the entire length of the grooved rod. It is thus possible to realize relatively large wrap angles of 60° and more.
Alternatively, it is also possible for the guide element to be formed by a guide strip comprising a plurality of protruding pins, which guide strip comprises the contact surface. It is thus possible to achieve a division and spread of the monofilaments or ribbons without large wrap angles.
For guiding the monofilaments or ribbons, the guide element is preferably assigned to any one of the treatment devices in an inlet zone and/or an outlet zone. If several treatment devices are used for producing a turf yarn, preferably several guide elements are assigned to several treatment devices in an inlet zone and/or an outlet zone each.
The apparatus according the invention will be explained below in more detail on the basis of an exemplary embodiment and with reference to the figures enclosed, in which:
Several treatment devices are disposed downstream of the extrusion device in order to stretch the monofilaments or to join several monofilaments and spool the same in the form of fiber bundles. In this exemplary embodiment, the first treatment device is formed by a cooling device 4 assigned to the extrusion device 1. The cooling device 4 comprises a cooling bath 5 disposed directly below the spinneret 3. Inside the cooling bath 5, a grooved rod 12 is disposed in the form of a guide element in order to separate the extruded monofilaments 6 and guide the same through the cooling bath 5.
For drawing and stretching the monofilaments, there are several conveyor systems 7.1 and 7.2 disposed in series that comprise several driven godets 8, on the circumference of which the monofilaments 6 are guided so as to extend parallel to each other and wrap around the godets once.
Between the cooling device 4 and the first conveyor system 7.1, there is a deflection device 9 provided that comprises several deflection rollers 15, on the circumference of which the monofilaments 6 are guided so as to wrap around the deflection rollers once. The deflection rollers 15 are disposed directly downstream of the cooling device 4 in order to wipe off the cooling liquid of the cooling bath 5 clinging to the monofilaments 6.
A heating device 10 is disposed between the conveyor systems 7.1 and 7.2. In this exemplary embodiment, the heating device 10 is formed by a circulating air oven, in which the monofilaments 6 are heated to a stretching temperature. For guiding the monofilaments, there are grooved rods 12 disposed in an inlet zone and an outlet zone each of the heating device 10 in order to be able to guide the monofilaments 6 through the hot air oven of the heating device 10 so as to extend separately parallel to each other. For stretching the monofilaments 6, the godets 8 of the conveyor systems 7.1 and 7.2 are driven with a difference of speed.
After the stretching process, the monofilaments 6 are combined in groups to form fiber bundles and supplied to a winding device 13 and a spooling device 14. For this purpose, there is a thread-guide strip 11 disposed between the last conveyor system 7.2 and the winding device 13, on which thread-guide strip 11 the monofilaments are guided and divided into several fiber bundles.
As shown in
In the exemplary embodiment shown in
Since such types of turf yarns exhibit high degree of elasticity, it is particularly necessary to guide the monofilaments with low friction. For this purpose, the guide elements such as the grooved rod 12 disposed inside the cooling bath 5 have a contact surface comprising a multiple coating.
20 is applied. A plurality of protruding pins 23 is attached to the top side 22 of the guide strip 11 so as to be disposed at a distance from each other. Thus a plurality of guide grooves 24 is formed, in which the monofilaments are guided side by side parallel to each other.
The exemplary embodiments of a guide element shown in
In order to enable low-friction and wear-resistant guidance of the monofilaments on the contact surfaces as far as possible, there is a multiple coating 20 applied to the contact surface 21.
In an exemplary embodiment of the grooved rod shown in
The multiple coating shown in
The exemplary embodiment of the apparatus of the invention shown in
The exemplary embodiment of the apparatus of the invention shown in
The configuration and arrangement of the treatment devices of the exemplary embodiment shown in
Number | Date | Country | Kind |
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10 2009 015 557.0 | Mar 2009 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP10/52902 | 3/8/2010 | WO | 00 | 8/30/2011 |