MXPA98003338A - Fi file package - Google Patents

Abstract

The present invention relates to an arrangement with the present invention for a filament spin pack containing one or more electroformed plates. The invention further provides a process for producing a plate for a spin pack, whose process has the step of electroforming the pla

Description

FIBER YARN PACKAGE BACKGROUND OF THE INVENTION The present invention relates to a spin pack. More specifically, the present invention relates to a spin pack containing one or more electroformed plates.

Spin packs for manufacturing melt process fibers or processed solution polymers are well known in the art. A bundle of spinning fibers of component fiber receives a processed and flowable stream of a polymer or a mixture of polymers and distributes the polymer stream to the spinning orifices to form a multitude of filaments. A bundle of multi-component conjugate fiber yarns contains a more complicated distribution system than separately distributing the currents of the component polymers at predetermined positions to the spinning orifices to form unitary filaments from each orifice.

In general, a spin pack is designed to have a number of modular sections or plates so that the spin pack can be easily cleaned and each plate can be replaced with a new or different plate.

Conventionally, the sections or plates of a spin pack are metal articles that are individually cut from a metal block to have several channels and holes. Consequently, the production of a spin pack is highly laborious and expensive, and it is highly laborious and difficult to produce exact duplicates of a spin pack or spin pack of spin pack.

Producing a spin package for multi-component conjugate filaments exacerbates the cost and problem of reproduction since a conjugate filament spin pack requires a complicated distribution design that allows precise distribution of different streams of flowable processed polymer compositions to through the spin pack without allowing the fibers to intermix.

There have been attempts to find less expensive methods to produce the spin pack plates. An example of such attempts uses a photochemical pickling process to produce plates for a spin pack. Even though the cost to produce pickled plates is relatively lower than milled plates, a chemical pickling process is not as accurate as a milling process, and therefore, the process of pickling production does not eliminate the problem of reproducibility.

There remains therefore a need for a spin pack production process that is less expensive and yet highly accurate and reproducible.

SYNTHESIS OF THE INVENTION The present invention provides a yarn package for filaments containing a distribution plate and a spinner organ plate, wherein the distribution plate is an electroformed plate. The invention further provides a process for producing a plate for a spin pack, which process has the step of electroforming the plate. Desirably, the electroforming step is an electroforming step having the steps of providing a photoresist coated conductive surface and a photomask, wherein the photomask contains a pattern of a plate configuration; place the photomask on the photoresist coated surface; exposing actinic radiation for an effective duration on the photomask to form exposed regions and unexposed regions; develop the photoresist of the photoresist coated surface; remove exposed or unexposed regions from the roof surface to form a removed pattern containing a conductive surface; place the surface containing the pattern removed in an electroforming device; electroforming a plate on the surface that contains the pattern; and remove the electroformed plate from the surface that contains the pattern.

The spin pack, more specifically the pack plates, of the present invention are highly reproducible and are easily produced as well as highly economical.

The term "conjugated fibers" refers to fibers that contain at least two polymeric components which are arranged to occupy sections other than essentially the entire length of the fibers. The conjugated fibers are formed by simultaneously extruding at least two compositions of melted polymer component as a plurality of unitary multicomponent filaments or fibers of a plurality of capillary vessels of a spinning organ. The terms "fibers" and "filaments" are interchangeably used herein to indicate the polymer fiber yarns formed by a spin pack, unless otherwise indicated.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 illustrates a photoresist coated conductive surface.

Figure 2 illustrates a pattern containing a photoresist coated surface.

Figure 3 illustrates an electroforming apparatus suitable for the present invention.

Figure 4 illustrates an electroformed article on a photoresist coated surface.

Figure 5 illustrates an example of a conjugate fiber configuration that can be produced according to the present invention.

Figures 6-12 illustrate electroformed distribution plates used to produce the conjugate fiber of Figure 5.

Figure 13 illustrates another example of a conjugate fiber configuration that can be produced according to the present invention.

Figures 14-17 illustrate electroformed distribution plates used to produce the conjugate fiber of the ? i look at T ^ DETAILED DESCRIPTION OF THE INVENTION A spin pack for producing flowable processed polymer filaments is provided according to the present invention. The present spin pack is particularly suitable for producing multi-component conjugated filaments containing more than one of the polymer components. The spin pack of the present invention can be used to produce a wide variety of fiber configurations. The exemplary fiber configurations that can be produced with the present spin pack include various conjugate fiber configurations, for example, side-by-side, sheath / concentric core, sheath / eccentric core of islands at sea and multi-segmented cake configurations; and various fiber shapes of cross section, for example, round, oval, rectangular, multilobal and tape forms. In addition, the spin pack can be used in various fiber forming processes, including spin bonding, meltblowing, textile fiber cutting and shortening processes, and can be adapted to different methods to fluidly process the component polymers including melt processing methods and solution processing methods.

The spin pack of the present invention contains one or more plates that are electroformed so that the plates are produced precisely and reproducibly. In addition, the cost of producing the plates is significantly lower than conventional milled or machined plates. The combination of reproducibility and the low cost of the present plates allows the plates to be disposable, in case such a practice is desired. It has been known theoretically that using disposable plates in the spinning packages is highly desirable since it is highly laborious and costly to clean the spinning pack plates, and therefore, it can be highly desirable to use disposable spin pack plates. However, in order to take advantage of the disposable concept, the cost of the spin pack plates has been made low enough to be economical and precise duplicates of the spin pack plates must be available. Hitherto, it has not been highly practical to use disposable spin pack plates since it has not been possible to economically produce accurate duplicates of the spin pack plates. As indicated above, the electroformed plates of the present invention are inexpensive and are precisely reproducible plates that make the concept highly practical. In general, a spin pack contains a top plate, a grid filter support plate and a spin plate. However, a spin pack may also contain other plates, for example, distribution plates, when the package is designed to produce fibers having a complicated configuration. For example, a spin pack for multicomponent conjugate fibers contains a top plate, a filter or grid support plate, one or more distribution plates and a spin plate. The top plate receives a flowable processed polymer composition or a flowable processed polymer composition and carries the polymer compositions to the grid support plate. The grid support plate which contains separate channels for the fluidly processed polymer compositions, filters the polymer compositions and feeds the polymer compositions to the spin plate or to the distribution plate if the spin pack contains distribution plates. In a conjugate fiber spin pack, which contains distribution plates, polymer compositions exiting the grid support plate are channeled through the distribution plates and are accurately distributed and placed to form a configuration of desired fiber. The properly distributed polymer compositions are then fed to the spin plate in which the compositions are joined to form a unitary filament.In accordance with the present invention, the plates for the spinning packs, particularly the distribution plates, are electroformed. Desirably, the plates are photoelectroformed. The electroforming, which is an extension of electrorecovery, is known in the art. A typical photoelectric forming process contains the steps of coating a photoresist layer on a flat conductive surface of an object; placing a photomask which contains a photographic image of a desired pattern on the photoresist layer; exposing the photoresist layer with actinic radiation through the photomask; develop the photoresist layer; removing the regions exposed or not exposed to the actinic radiation of the photoresist, thereby selectively discovering the regions of the conductive surface to equalize the positive or negative pattern of the photomask; placing the object, which contains a coating with photoresist pattern, in an electroforming apparatus, depositing the metal on the uncovered regions to a desired thickness to form a metal article; and separating the metal article, which is designed according to the photomask, from the conductive surface.

Figure 1 illustrates an exemplary photoelectroformer process suitable for the present invention. An electroforming process begins with an object 10, desirably a sheet, having a highly polished electrically conductive flat surface 12. The object can be an electrically conductive material, for example, a sheet of metal, or a dielectric material, for example a sheet non-conductive plastic, a plastic film or a glass plate, which is conductively modified. When a dielectric material is employed, a layer of electrically conductive material requires coating or depositing on the flat surface. Any conventional metal coating technique, such as vacuum deposition, spraying, chemical vapor deposition or pyrolytic coating process, can be used to form the conductive surface on the dielectric material. Desirably, the spraying process is used to deposit an even layer of conductive material, such as indium, chromium or copper, to form the conductive surface 12. On the conductive surface 12, an even plate of a photoresist 14 was applied, for example Hoechst AZ1518, and then the photoresist plate was cured to form an electrically non-conductive surface.

Separately, a photomask or photonegative was prepared photographically of a master pattern, for example, a CAD (computer aided drawing), of a spinning pack plate. For example, a photomask is formed by projecting a photographic pattern of a plate onto a transparent sheet coated with silver halide and then revealing the sheet to form an exact image of the pattern. The revealed photomask has a pattern of transparent actinic radiation and opaque regions.

The photomask is placed on the photoresist coated surface described above 14, and then the actinic radiation is applied on the photoresist layer through the photomask, thereby creating a pattern of exposed and unexposed photoresist regions that duplicate precisely the photomask pattern . The photoresist layer is developed with a solvent that removes the unexposed parts of the photoresist, and therefore, a pattern of conductive regions is formed which corresponds to the pattern of the photomask and are separated by the remaining photoresist on the conductive surface. Alternatively, a solvent system that removes exposed regions from the photoresist can be used to form a negative image or pattern of the photomask.

The mandrel-containing photoresist object with pattern 18, Figure 2, is then placed in an electroforming apparatus 20, Figure 3, which contains a conventional metal-containing electrodeposition solution 22 and is connected to a DC current source 24. The conductive surface 12 of the mandrel 18 was connected as a cathode and a metal electrode 26 is connected as an anode. The metal electrode 26 supplies the metal ion which is deposited on the conductive surface of the mandrel, 18 to form a plate according to the pattern formed by the photoresist. A number of different hard metals and corresponding electroforming solutions that are known to be suitable for conventional electrocoating or electroforming operations can be used. For example, a nickel plate can be formed by employing a nickel electrode and an electroforming solution containing from 300 to 450 g of nickel sulfonate, from 0 to 10 g of nickel chloride and from 30 to 45 g of boric acid per liter of water. Other metals suitable for the electroforming process of the present invention include chromium, bronze, copper, platinum, gold, tin and steel.

During the electroforming operation, the mandrel 18 receives and accommodates the metal ions only in the regions 16, as shown in Figure 2, in which the photocurable substance is removed and the conductive surface is exposed. The electroforming operation is continued until the electroformed plate achieves a desired level of thickness. As is known in the art of electroforming, electroformed plates can be produced at different levels of thickness. According to the disposable plate concept described above, the particularly desirable plates for the disposable concept have a thickness between about 0.05 millimeters and about 1.3 millimeters, more desirably between about 0.1 millimeters and about 0.5 millimeters. The mandrel 18 is then removed from the electrodeposition solution, and the electroformed plate 19, as shown in Figure 4, is separated from the mandrel 18. The separation of the mandrel plate can be effected by various known means, such as heating and alternatively cooling the mandrel or dissolving the mandrel.

Even though the electroforming process of the present invention is described above with an electroforming process, the process for producing a pattern containing conductive surface, for example, the mandrel-forming process can be achieved by other equivalent means. For example, the non-conductive material, for example, a polymeric film can be mechanically cut with a blade or chemically coated or electromechanically cut with a laser beam to have a desired pattern of non-conductive regions. The patterned material is then surely fixed, for example adhesively, on the conductive surface to form a pattern containing a rolled mandrel. The mandrel is then subjected to an electroforming process such as the process described above to produce the electroformed plate.

According to the present invention, in a spin pack, there can be more than one of the distribution plates that are stacked to the top to provide the desired distribution channels which evenly distribute the appropriate amounts of the polymer compositions fluidly processed to the fibers. For example, Figure 5 illustrates a bicomponent fiber conjugate of ten and six pie segments that can be produced in accordance with the present invention. Figures 6-13 illustrate 8 distribution plates which are stacked in that order to form a complete distribution plate set suitable for producing the aforementioned bicomponent fiber. The distribution plates are illustrated with a spinner that produces a bicomponent fiber yarn. A first distribution plate, Figure 6 contains two holes 40 and 42 that separately receive a first fluid-processed polymer composition and a second fluid-processed polymer composition. A second distribution plate, Figure 7, contains an elongated horizontal hole 44, which receives the first polymer composition from the left end and passes the composition to the right end of the hole, and an outer semicircular hole 46, which receives the second. polymer composition in the center and passes the composition to the two ends of the semicircular hole 46. The second distribution plate is followed by a third distribution plate, Figure 8, which contains two outer holes 48, which are aligned with the two ends of the semicircular hole 46 of the second plate, and a third plate central hole 50, which is aligned at the right end of the elongated horizontal hole 44 of the second plate. The polymer compositions leaving the third plate are then passed over a fourth plate, Figure 9. The fourth plate contains two outer elongated holes 52, whose centers are aligned with the outer holes 48 of the third plate, and a central hole of the fourth plate 54, which is aligned with the central hole of the third plate 50. The four tips of the two outer elongated holes 52 are aligned with four outer holes 56 of a fifth plate, Figure 10, thus providing equal amounts of the second polymer composition to the four outer holes 56. The fifth plate 10 also contains a central hole of fifth plate 58 which receives the first polymer composition from the central orifice of the fourth plate 54. The sixth plate , Figure 11, contains a star-shaped hole 60 having eight points and four holes in the shape of "V" 62. The eight ends of the four orifices 62 of "V" shape are placed to occupy the eight spaces formed between the tips of the star-shaped hole 60, whereby the tips of the star-shaped orifice 60 and the ends of the "V" -shaped orifices 62 are alternately aligned you in a concentric way. The four outer holes 56 of the fifth plate are placed directly on the center of the four holes "V" shaped, and the central hole of the fifth plate is placed in the center of the star-shaped hole 60. The seventh plate it contains sixteen concentrically placed holes 64 that are equidistant from each other and are of the same size. The sixteen holes 64 are alternately positioned below the tips of the star-shaped hole 60 and the ends of the "V" shaped holes 62. Consequently, the sixteen holes 64 alternately receive the first flowable processed polymer compositions. and second.

The polymer compositions are then passed into the orifice of the spin plate in a laminar form to prevent measurable intermixing of the compositions, and the polymer compositions are fused into a unitary yarn containing ten and six segments. The unit yarn was gradually made into a thin thread as it passed through the spinning plate orifice and out of the spin pack as a small filament retaining the sixteen pie-shaped segments.

As another example, Figure 13 illustrates a sheath / core bicomponent fiber that can be produced according to the present invention. The yarn package for the sheath / core conjugate fiber contains four distribution plates. A first distribution plate, Figure 14, contains a first orifice 66 and a second orifice 68 that separately receive a first flowable processed polymer composition and a second flowable processed polymer composition respectively. A second distribution plate, Figure 15, contains an elongated horizontal hole 70, which receives the first polymer composition from the left end and passes the composition to the right end of the hole 70, and an outer semicircular hole 72, which receives the second polymer composition in the center of the semicircular hole 72. The second plate is followed by a third plate, Figure 16, which has a central hole 74 and three outer holes 76, 78 and 80. The central hole 74 is aligned with the right end of the second elongated horizontal hole 70. Two of the three outer holes (tip holes), 76 and 80, are aligned with the two outer ends of the semicircular hole 72 of the second plate, and the remaining outer hole (center hole) 78 is located in the center of the semicircular hole 72. It should be noted that the central hole 78, which is essentially aligned with the second hole 68. of the first plate through the semicircular hole 72 is smaller than the tip holes 76 and 80. The small size of the central hole 78 prevents a disproportionately large amount of the second flowable processed composition from going through the center hole 78 and distributing evenly or suitably the composition to the three outer holes 76, 78 and 80. The polymer compositions leaving the third plate are then passed over a fourth plate, Figure 17. The fourth plate contains a large hole that allows the second composition flowable process leaving the three outer holes 76, 78 and 80 to spread and merge horizontally forming a sheath configuration around the first composition leaving the central hole 74. The compositions are then passed into the hole of the spinning plate for form a conjugate sheath-core filament.

Even though the present spin pack is illustrated above with conjugated fibers containing two polymer components, the present invention is not limited thereto. The shapes and designs of the orifice channels of the distribution plates can be changed according to the various fiber configurations that are sought to be produced. Such changes and designs of the channels and holes of the plates are within the general knowledge of one skilled in the art of the spin pack. In addition, the electroforming process of the present invention can be used to produce distribution plates having various sizes of distribution orifices and, therefore, deliver different amounts of fluidly processed polymers to different spinning orifices of the spin plate. A package of yarn containing such distribution plates having varying orifice sizes can be used to produce a non-woven fabric containing heterogeneous filaments of different sizes. Additionally, the electroformed distribution plates of the present invention can be used in combination with the conventionally produced distribution plates, and the electroforming process of the present invention can be used to produce various parts and plates of a spin pack even when the invention is described. in conjunction with the distribution plates.

As indicated above, the present electroforming process for producing the distribution plates is highly accurate and reproducible as well as very economical. In addition, the present process is highly adaptable to produce fibers having various configurations.

Claims (20)

R E I V I N D I C A C I O N S

1. A yarn package for filaments, comprising a spinning plate and a distribution plate, wherein said distribution plate is an electroformed plate.

2. The spin pack as claimed in clause 1 characterized in that said distribution plate is electroformed.

3. The spin pack as claimed in clause 1 characterized in that said spin pack comprises a multitude of distribution plates.

4. The spin pack as claimed in clause 1, characterized in that the distribution plate comprises nickel, chromium, bronze, copper, silver, gold, tin or steel.

5. The spin pack as claimed in clause 1, characterized in that said distribution plate has a thickness between about 0.002 inches and about 0.05 inches.

6. The spin pack as claimed in clause 5, characterized in that the distribution plate has a thickness between about 0.004 inches and 0.02 inches.

7. The spin pack as claimed in clause 1 further characterized in that it comprises a top plate and a grid support plate.

8. The spin pack as claimed in clause 2 characterized in that said distribution plate comprises nickel.

9. The spin pack as claimed in clause 8, characterized in that said spin pack is a spin pack for side-by-side, concentric sheath-core, eccentric sheath-core, island-in-sea fibers or conjugate fibers. of mui-segmented cake.

10. A plate for a spin pack, wherein said plate is an electroformed plate.

11. The plate as claimed in clause 10 characterized in that said plate is a distribution plate.

12. The plate as claimed in clause 11 characterized in that said plate is photoelectroformed.

13. The plate as claimed in clause 12 characterized in that said plate is a metal plate comprising nickel, chromium, bronze, copper, silver, gold, tin or steel.

14. The plate as claimed in clause 13 characterized in that said plate has a thickness between about 0.004 'inches and 0.05 inches.

15. The plate as claimed in clause 12 characterized in that said plate is a nickel plate having a thickness between about 0.004 inches and 0.02 inches.

16. A process for producing a plate for a spin pack, whose process comprises the step of electroforming said plate.

17. The process as claimed in clause 16 characterized in that the electroforming step is a photoelectroformation step.

18. The process as claimed in clause 17 characterized in that said photoelectroformation step comprises, in the following order: a) providing a conductive surface coated with photoresist and a photomask, said photomask containing a pattern of a plate configuration, c) placing said photomask on said surface coated with a photoresist, d) exposing the actinic radiation for an effective duration on said photomask to form the exposed regions and the unexposed regions e) revealing the photo-hardenable substance on said coated surface of photohardenable substance, d) removing the exposed or unexposed regions of said coated surface to form a removed pattern containing conductive surface, e) placing said surface containing the removed pattern in an electroforming apparatus, f) electroforming a plate with said surface containing a standard, and g) removing the electroformed plate from said surface containing the standard.

19. The process as claimed in clause 18 characterized in that said electroformed plate is a metal plate comprising nickel, chromium, bronze, copper, silver, gold, tin or steel.

20. The process as claimed in clause 19 characterized in that said plate has a thickness between about 0.002 inches and about 0.05 inches. SUMMARY A yarn package for filaments containing one or more electroformed plates is provided according to the present invention. The invention further provides a process for producing a plate for a spin pack, which process has the step of electroforming the plate.