Title of Invention

A DEVICE FOR WETTING AN ADVANCING GROUP OF FILAMENTS

Abstract

The present invention relates to a device for wetting an advancing group of filaments. The device comprises a carrier, a wetting insert mounted to the carrier, and.a pressure chamber formed inside the carrier for receiving a wetting agent. The wetting insert includes in an outer contact surface that is contacted by the group of filaments, a plurality of openings, which connect directly to the pressure chamber. To have a wetting agent emerge in uniform metered quantities over the unit area of the contact surface, the invention provides for forming the wetting insert by a thin-walled perforated plate with openings distributed in a regular pattern.

Full Text

DEVICE FOR WETTING AN ADVANCING GROUP OF FILAMENTS The invention relates to a device for wetting an advancing group of filaments as defined in the preamble of claim 1. A generic type of the device is disclosed, for example, in DE 199 45 699 Al. When spinning a synthetic multifilament yarn, a plurality of strandlike filaments are extruded by means of a spinneret in a first step. They are then cooled as a group of filaments and combined to a yarn. In this process, a lubricant is applied to the group of filaments during or shortly before combining the group of filaments, for purposes of generating on the one hand cohesion of the individual filaments, and for preventing on the other hand too high friction effects in the yarn guide means. In the known device, one advances the multifilament yarn with contact over a wetted contact surface for applying the yarn lubricant. The contact surface comprises in the contacted surface region a plurality of pore-shaped openings that connect via a plurality of capillaries to a pressure chamber. The contact surface is provided on a wetting insert, which is made of a porous material. To this end, it is preferred to use sintered ceramic materials, wherein the arrangement and distribution of the capillaries and pore-shaped openings are very irregular. In addition, the arrangement of the group of filaments in the form of bundles complicates a distribution of the lubricant being applied to each individual filament strand. It is therefore an object of the invention to further develop the known device such that a wetting agent, which emerges in uniformly metered quantities, is constantly present on the contact surface. A further object of the invention is to provide a device for wetting a group of filaments, wherein each of the filament strands of a group of filaments forming a yarn is evenly wetted. This object is accomplished by a device with the features of claim 1. Advantageous further developments of the invention are defined by the features and feature combinations of the dependent claims. The invention is characterized in that each region of the group of filaments that advances along the contact surface comes into contact with a wetting agent that emerges in uniformly metered quantities. To this end, the invention provides for a wetting insert that is formed by a thin-walled perforated plate with openings that are distributed in a regular pattern. In each region of the contact surface the same quantity of wetting agent emerges from the openings that are distributed in a regular pattern. An advantageous further development of the invention, wherein the perforated plate has a curvature directed into the path of the advancing yarn to guide the group of filaments over the contact surface with a minimum looping, causes the group of filaments to spread, so that essentially each filament strand of the group of filaments is able to advance along the contact surface in contact therewith. As a result of this spreading, an essentially identical quantity of the wetting agent is applied to each filament strand. Depending on the speeds of the advancing yarn, it is possible to use perforated plates with different opening cross sections. Thus, it is preferred to use at high yarn advancing speeds perforated plates with larger opening cross sections of up to 100 /xm and at correspondingly lower yarn advancing speeds perforated plates with smaller opening cross sections of up to 10 fxm. In this connection, it has been found that the contact range between the group of filaments and the contact surface should extend over a length from 5 to at most 2 0 mm. To obtain a finest possible pattern of great accuracy and, thus, a high metering accuracy, perforated plates that are constructed as an electroformed carrier plate with continuous openings separated by ridges have been found especially reliable. As a result of the galvanic production process, perforated plates of this type possess a high edge roundness in the region of the contact surface, which enables a protective advance of the yarn. With that, it is possible to realize in addition a large number of openings per unit area. To prevent soiling and, with that, a partial closing of the openings, a further development of the invention has been found especially advantageous, wherein the ridges formed between the openings have a shape that tapers toward the contact surface. With that, it is possible to form funnel-shaped opening cross sections, which cause a self-cleaning effect. To be able to obtain a longest possible service life, the contact surface of the perforated plate is provided with a coating to protect it against wear. With that, it is also possible to provide contact surfaces of low friction, which results in a very protective advance of the yarn while being wetted. To wet as much as possible simultaneously a plurality of groups of filaments that each form a yarn, the further development of the invention is preferred, wherein the carrier mounts a plurality of perforated plates in spaced relationship, with one group of filaments being associated to each perforated plate. In the following, further advantages of the invention are described in greater detail by means of some embodiments with reference to the attached drawings, in which: Figure 1 is a schematic view of a first embodiment of the device according to the invention; Figure 2 is a schematic fragmentary view of the embodiment of Figure 1; Figure 3 is a schematic cross sectional view of the embodiment of Figure 1; Figure 4 is a schematic fragmentary view of a further embodiment of the device according to the invent ion; and Figure 5 is a schematic view of a further embodiment of the device according to the invention. Figure 1 illustrates an embodiment of the device according to the invention when used in a spinning process. The embodiment of the wetting device is indicated by the numeral 15. In the spinning process, a group of filaments 3 is extruded by means of a spinneret 2. To this end, a polymer melt supplied to a spin head 1 is squeezed under pressure through a plurality of spin holes of the spinneret 2. In the spinning process, the filament strands of the group of filaments 3 emerging from the spinneret 2 are jointly cooled and wetted after cooling with a wetting agent, preferably an oil-water emulsion. To this end, the wetting device 15 is arranged in a convergence region of the group of filaments 3. Directly associated to the wetting device 15 is a yarn guide 16, which combines the group of filaments 3 to a yarn 17. The description of the wetting device 15 proceeds by simultaneously referring to Figures 2 and 3, of which Figure 2 is a front view and Figure 3 a cross sectional view of the wetting device 15 of Figure 1. The wetting device 15 comprises a carrier 4, which includes a closed pressure chamber 6. The pressure chamber 6 connects inside the carrier 4 via a line 14 to a pump 12 and a tank 13. On its side facing the group of filaments 3, the carrier 4 comprises a wetting insert 5 that directly connects to the pressure chamber 6. The wetting insert 5 is formed by a thin-walled perforated plate 9. The perforated plate 9 contains in a contact surface 8 a plurality of openings 10, which are arranged in a regular pattern in the perforated plate 9. The perforated plate 9 has the contact surface 8 on its outer side. Preferably, the contact surface 8 is provided with a coating to ensure as much as possible a low-friction and protective advance of the group of filaments 3. To this end, the perforated plate 9 is constructed with a curvature directed toward the advancing yarn to obtain a spreading the group of filaments 3 by a minimal looping on the contact surface 8. As shown in Figures 1-3, the carrier 4 could be formed, for example, by a tube section that is closed at its two face ends. Connected to one of the face ends of the tubular carrier is pump 12 via line 14. From a tank 13, the pump 12 delivers a wetting agent 11 under pressure into the pressure chamber 6 inside the carrier 4. On its circumference, the tubular carrier 4 includes a cutout for receiving the perforated plate 9. The perforated plate 9 directly connects to the pressure chamber 6, so that the wetting agent 11 being under an overpressure emerges on the contact surface 8 from the openings 10 of the perforated plate 9. For purposes of wetting, the group of filaments 3 advances with a minimal looping along the contact surface 8. The quantity of the wetting agent that emerges in a uniformly metered amount on the contact surface 8 leads to a uniform wetting of all filament strands of the group of filaments 3. The perforated plate 9 contains openings 10 preferably only in the area of direct contact with the group of filaments 3. The length L of the contact area extends, depending on the diameter D of the openings and depending on the speed of the advancing yarn, in a range from 5 mm to as much as 2 0 mm. To obtain in this process an adequate wetting of the group of filaments 3, one uses perforated plates with opening cross sections from 10 ^tm to 100 £tm. The size of the openings as well as the length of the contact surface can be varied in a simple manner by exchanging the perforated plates or by varying the looping angle of the group of filaments on the perforated plate 9. Thus, it becomes advantageous and possible to wet fine and coarse deniers with one and the same device. In the embodiment of the device according to the invention as shown in Figure 3, the perforated plate 9 has openings 10 only the region of the contact surface 8. However, it is also possible that regions, in which no contact occurs between the filaments of the group of filaments 3 and the perforated plate 9, contain additional openings for purposes of providing a larger fluid quantity on the contact surface in particular in the regions upstream of the initial contact of the group of filaments. Figure 4 illustrates an enlarged fragment of a further embodiment of the device according to the invention. The components of the device not shown in Figure 4 are identical with the foregoing embodiment, so that their description is herewith incorporated by-reference. In the case of the wetting device shown in Figure 4, the perforated plate is formed by an electroformed carrier plate 18. When electroforming the perforated plate, a matrix is used which comprises a grid of electric conductors. The electric conductors define the ridges being formed, and insulators define the openings being formed. In an electrolytic bath, metal is deposited by a galvanic process on the electric conductors up to a desired thickness. Thereafter, the resultant carrier plate is removed from the matrix. Thus, the carrier plate 18 comprises a plurality of ridges 19, which form the openings 10. The ridges 19 have a shape that tapers in the direction of the contact surface, so that the openings 10 are made funnel-shaped. This funnel-shaped construction of the openings 10 allows to accomplish that dirt particles or abrasive particles are unable to settle in the openings. In addition, carrier plates 18 of this type distinguish themselves by a high degree of roundness, which enables a particularly protective advance of the yarn. Figure 4 illustrates the situation, in which the wetting agent 11 emerges from the pressure chamber 6 through the openings 10 on the contact surface 8. Along the contact surface 8, a filament strand of the group of filaments 3 advances. Preferably, the electroformed carrier plate 18 is made from a nickel material. With the use of this material, it is possible to provide in the carrier plate 18 a large number of openings per unit area. The thickness of such an electroformed carrier plate is normally on the order of 100 /xm, although it is possible to construct both thinner and thicker carrier plates. Figure 5 illustrates a further embodiment of a device according the invention when used in a spinning process. In this embodiment, the wetting device 15 is formed by an elongate carrier 4, which comprises in spaced relationship a plurality of wetting inserts 5.1-5.4. Associated to each wetting insert 5.1-5.4 is one of a plurality of groups of filaments 3.1-3.4. The groups of filaments 3.1-3.4 are extruded from separate spinnerets 2.1-2.4. To this end, the spinnerets 2.1-2.4 are mounted to a spin head 1. The wetting device 15 receives a wetting agent via a pump 12 from the tank 13. In this arrangement, the carrier 4 includes a pressure chamber 6, which connects to the wetting inserts 5.1-5.4 that are constructed in the form of perforated plates. Arranged in the direction of the advancing yarn, directly downstream of each of the perforated plates, are yarn guides 16.1-16.4, which combine each of the groups of filaments 3.1-3.4 to a yarn 17. NOMENCLATURE 1 Spin head 2 Spinneret 3 Group of filaments 4 Carrier 5 Wetting insert 6 Pressure chamber 8 Contact surface 9 Perforated plate 10 Openings 11 Wetting agent 12 Pump 13 Tank 14 Line 15 Wetting device 16 Yarn guide 17 Yarn 18 Carrier plate 19 Ridges CLAIMS 1. Device for wetting an advancing group of filaments (3) comprising a carrier (4), a wetting insert (5) mounted to the carrier (4) , and a pressure chamber (6) formed inside the carrier (4) for receiving a wetting agent, with the wetting insert (5) including on an outer contact surface (8) contacted by the group of filaments (3), a plurality of openings (10) , which connect to the pressure chamber (6) , characterized in that the wetting insert (5) is formed by a thin-walled perforated plate (9) with openings (10) distributed in a regular pattern. 2. Device of claim 1, characterized in that the perforated plate (9) comprises a curvature directed into the path of the yarn to guide the group of filaments (3) with a minimal looping over the contact surface (8). 3. Device of claim 1 or 2, characterized in that the opening cross sections of the openings (10) in the perforated plate (9) have a diameter in a range from 10 Mm to 10 0 iim. 4. Device of claims 1-3, characterized in that the contact surface (8) extends in the direction of the advancing yarn over a length in a range from 5 mm to 2 0 mm. 5. Device of one of claims 1-4, characterized in that the perforated plate (9) is constructed as an electroformed carrier plate (18) with continuous openings (10) separated by ridges (19). 6. Device of claim 5, characterized in that the ridges (19) formed between the openings (10) have a shape tapering toward the contact surface, so that funnel-shaped opening cross sections are formed in the carrier plate (18). 7. Device of claim 5 or 6, characterized in that the electroformed carrier plate (18) is made of nickel. 8. Device of one of claims 1-7, characterized in that the perforated plate (9) includes on its contact surface (8) a coating for protection against wear. 9. Device of one of the foregoing claims, characterized in that the carrier (4) mounts in spaced relationship a plurality of perforated plates (9), with one of a plurality of groups of filaments (3) which each form a yarn, being associated to each of the perforated plates (9) • 10. Device of one of claims 1-9, characterized in that ABSTRACT A device for wetting an advancing group of filaments is described. The device comprises a carrier, a wetting insert mounted to the carrier, and a pressure chamber formed inside the carrier for receiving a wetting agent. The wetting insert includes in an outer contact surface that is contacted by the group of filaments, a plurality of openings, which connect directly to the pressure chamber. To have a wetting agent emerge in uniform metered quantities over the unit area of the contact surface, the invention provides for forming the wetting insert by a thin-walled perforated plate with openings distributed in a regular pattern.

Documents:

2143-chenp-2005 abstract-duplicate.pdf

2143-chenp-2005 claims-duplicate.pdf

2143-chenp-2005 descritpion (complete)-duplicate.pdf

2143-chenp-2005 drawings-duplicate.pdf

2143-chenp-2005-abstract.pdf

2143-chenp-2005-claims.pdf

2143-chenp-2005-correspondnece-others.pdf

2143-chenp-2005-correspondnece-po.pdf

2143-chenp-2005-description(complete).pdf

2143-chenp-2005-drawings.pdf

2143-chenp-2005-form 1.pdf

2143-chenp-2005-form 3.pdf

2143-chenp-2005-form 5.pdf

2143-chenp-2005-form18.pdf

2143-chenp-2005-pct.pdf