CN1500161A - Polymer filaments with profiled cross-sections - Google Patents

Abstract

This invention provides a profiled polymer filament having an open, hollow cross-sectional shape perpendicular to the longitudinal axis of the filament, wherein the dimensions of the cross-section prevent the filament from interlocking with a second filament having the same cross-section. This invention also provides a method for manufacturing such a filament by melt spinning polyamide, and a spinneret suitable for melt spinning such a filament.

Description

Polymer filaments with profiled cross-sections

field of invention

The present invention relates to synthetic polymeric filaments having an "open hollow" profiled cross-section perpendicular to the longitudinal axis of the filament. The invention also relates to a spinnerette for the melt extrusion of filaments, and to a method of producing filaments by melt extrusion.

Background technique

Textile fibers or filaments derived from synthetic polymers, especially polyamide polymers like nylon 66 and nylon 6, and multifilaments melt-extruded from similar polyamide polymers are usually produced as partially oriented yarns (POY) and drawn Stretch silk to make clothes. POY will have an elongation at break of greater than about 55% and drawn yarn will have a lower elongation. A circular shape is the most common cross-sectional shape for each of the filaments composed of multifilaments of various types such as POY and drawn yarns. Variations in special filament cross-sectional shapes including three-lobe or six-lobe shapes have been disclosed by Japanese patent document JP01-20243 (Nihon Ester KK), and fan-shaped elliptical cross-sections have been disclosed by U.S. Patent No. 5,834,119 (Roop) , while hollow polyamide filaments with a single longitudinal void have been disclosed in US Pat. No. 5,604,036 (Bennett et al.).

All the above examples known POY and drawn yarns of various profiled cross-sectional shapes. Filaments with some cross-sectional shape rather than circular shape provide multifilaments for fabrics and garments with varying visible appearance, opacity and protection, and lighter weight. Yarns composed of hollow filaments, such as the yarns of the aforementioned US patents, provide lighter weight fabrics and garments and have enhanced heat resistance properties compared to conventional round filaments. Hollow filament yarns are especially suitable for garment applications when extruded by conventional processes such as air jet texturing (AJT) and false twist texturing (FTT) to obtain bulky yarns. Hollow flat yarns for direct use in the weaving field are also known.

High void volume hollow form partially oriented and flat nylon yarns have been disclosed by Bennett et al. However, filaments with longitudinal voids are difficult to close well during spinning and actually lose their shape during texturing. This may result in a "C-shaped" filament and/or flattened tube cross-sectional shape. The C-shaped filaments can be tightly packed together with the notches of the open spaces in adjacent filaments. Furthermore, as a result of such occurrences, the letter C shaped cross-section filaments and flattened tube cross-sections produce poor yarn and fabric properties. Increased fabric density and reduced thermal resistance of fabrics and garments are undesirable characteristics. Furthermore, yarns composed of filaments with various broken longitudinal voids contribute to the streaking of dyed fabrics while undamaged filament voids provide room for occasional bacteria to develop.

It has now been found that the disadvantages listed above can be overcome by a polymer filament product having a novel cross-section.

The present invention provides a shaped filament of synthetic polymer having an "open hollow" cross-sectional shape perpendicular to the longitudinal axis of the filament. Its cross-section is dimensioned such that the first filament avoids linking up with a second filament of the same cross-section. This means that the areas closer to each end of the cross section are wider than the gap between said areas defining the opening of the open hollow cross section.

The shaped cross-section filaments of the present invention are provided by the novel shape and design of the extrusion capillaries. The filaments of this invention are prepared directly by melt extruding synthetic polymers through a multicapillary spinneret. The term "open hollow" generally means a C-shaped or U-shaped cross-section having a hollow center and a solid region defining a wall extending around the hollow center to enclose the hollow center but on one side of the wall An opening on the center connects the outside of the filament. The opening is narrower than the diameter of the hollow center, thereby forming a throat or constriction between the hollow center and the outside of the filament.

Preferably, the filament comprises a solid portion substantially surrounding the central hollow region. An opening leads from the exterior of the filament to the central hollow region. The solid part consists of two branches, said branches terminating at the bottom. The two opposing surfaces of the base define the neck (narrowest dimension) of the opening. The neck of the opening subtends a radial angle α not greater than 90°, preferably not greater than 75°, most preferably from 10° to 60°. As seen in FIG. 1 , the radial angle α is defined as the angle between the two rays R1 and R2 originating at point C. Point C is located on the inner surface of the solid portion of the filament which is furthest from the reference line R3 connecting the bottom end points tangentially. Each ray R1, R2 extends from point C and tangentially defines a point on the bottom opposite surface of the throat of opening D. The solid portion subtends a radial angle equal to 360° minus α (360° - α). Preferably, the solid portion of the cross-section subtends a radial angle of at least 270°. More preferably the solid portion subtends a radial angle of at least 300°.

The filaments according to the invention are suitable for avoiding interlocking or stacking of the filaments. For example, hook-like engagement of two cross-sections due to insertion of an end of a solid portion of a first filament cross-section into an opening in a second filament cross-section is avoided. This precaution can be achieved by what has been said, by subtending a substantial portion of the cross-section at a large radial angle, enabling very small openings in the cross-section of the filament. Alternatively, the ends of the solid portion of the cross-section may be enlarged to prevent insertion into openings of other filaments.

The solid portion of the cross-section in a filament according to the invention may form a single continuous curve. Preferably, the cross-section includes a "central arc" or base having first and second end portions and two side or "branch" portions. The branch portion extends from the first and second end portions of the central arcuate portion in substantially side-by-side relationship to each other.

In some preferred embodiments, such as the filament cross-sectional geometry shown in Figure 1, the filament cross-sectional shape is characterized by a central arcuate portion 1 (extending horizontally in Figure 1) and connected to the central arcuate portion The first and second, generally parallel, elongated branch portions 2, 3 (extend vertically in FIG. 1). An enlarged base 4 is defined relative to the end portions of the branches (2, 3) joined to the central arcuate portion 1 . Each bottom 4 is characterized by a dimension length F, the length of the bottom, as shown in FIG. 1 . The profiled filament cross-section is open in the center. This open portion is joined on three sides by the branch portions 2, 3 and the central arc-shaped base 1. The bases 4 are oriented in substantially side-by-side relationship, defining between facing surfaces of the bases an aperture having a dimension D leading to an open portion, as shown in FIG. 1 . Dimension D is smaller than dimension F. As a result, any base on any branch of a profiled filament is sufficiently large relative to the aperture between paired branches on any other like filament so that the base of the first filament avoids being accommodated (joined) in the multifilament Between other filament branches in the yarn bundle, as shown in Figure 2.

Preferably, the polymer used to form shaped polymer filaments according to the invention is a polyamide. More preferably, the polyamide polymer has a relative viscosity of greater than 40 according to the formic acid method, and more preferably the relative viscosity of the polyamide is in the range of 46 to 56 according to the formic acid method. Preferably, the polyamide is selected from the group consisting of nylon 66 and nylon 6 and copolyamides.

Preferably, the linear density per filament is from 0.5 to 20 decitex, more preferably it is from 2 to 10 decitex. Most preferably it is less than 4 decitex. Preferably, the cross-sectional shape of the filament is substantially constant along the length of the filament. Preferably, the filament non-uniformity is less than 1% Uster non-uniformity.

The profiled filaments according to the invention provide a lighter basis weight yarn, especially after AJT (Air Jet Texturing) or FTT (False Twist Texturing). Yarns contain high free volume air spaces. The air volume helps to enhance the thermal resistance of fabrics and garments produced from the yarn. When the yarn is knitted or woven into a fabric, the yarn provides a less dense fabric than a similarly structured fabric composed of filaments of completely circular cross-section. Furthermore, the yarn exhibits a high moisture absorption capacity.

The invention therefore also provides a multifilament comprising at least a portion of the shaped filaments according to the invention.

Preferably, the yarn comprises at least 10% by weight of the profiled filaments according to the invention, more preferably at least 25% of such filaments, more preferably at least 50% of such filaments. filaments, and preferably it consists essentially of such filaments.

The invention further provides an article comprising at least a portion of a yarn according to the invention. Preferably, the article comprises a fabric knitted or woven from a yarn according to the invention.

Another aspect of the invention is a spinneret for producing profiled open hollow filaments according to the invention by melt extrusion of polymers into filaments. The spinneret includes a spinneret having upper and lower surfaces connected by a capillary assembly. The shape, size and configuration of the capillaries are suitable for the melt spinning of the filaments according to the invention. In particular, any capillary consists of two adjacent segments, as shown in Figure 3a, and therefore, since the molten polymer streams of each segment merge at a point between the segments or each capillary has an open hollow cross-section as shown in Figure 3b, it can An open hollow filament cross-section is obtained longitudinally along the filament axis.

A preferred spinnerette for producing profiled open hollow filaments is one having capillaries consisting of two segments as shown in Figure 3a. Each segment is formed from a straight segment portion 30 having a junction at each end which has a pair of raised portions. At the first end, the pair of projections are of equal area and each projection comprises a rectilinear portion 31,32 terminating in a circular portion 33,34. At the second (opposite the first) end, it has a pair of raised portions of unequal area. The first unequal-area convex portion is composed of a straight line portion 35 and a circular portion 36 and the second unequal-area convex portion is composed of a straight line portion 37 and a circular portion 38 . Thus, each segment of the capillary has three equal bulges, two at one end and one at the opposite end. The unique (longer) projections provided on each segment are made up of a straight portion 37 and a circular portion 38 . Preferably, each capillary segment is a mirror image of the other segment. Preferably, each segment is a non-overlapping mirror image of the other segment, such as exemplified by Figure 3a. The non-overlapping mirror relationship means that each segment has the same convenience as people's left and right hands.

The open hollow filament cross-section perpendicular to the longitudinal axis of the filament is obtained when the molten thermoplastic polymer from each capillary segment merges at a point between the bulges of the two segments. That is, the open hollow filament cross section of the present invention is formed when molten polymer streams merge between the left and right capillary segment facing circular portions 38 shown in Figure 3a.

In the case where the capillary itself has an open hollow cross-section, the capillary shown in Figure 3b is a preferred spinner geometry cross-sectional shape for producing shaped open hollow filaments. Each capillary has a cross-sectional shape including a first straight portion 40 having first and second ends opposite to each other. The second straight portion 48 and the third straight portion 50 are branched from the first end of the first straight portion 40 . The second straight portion 48 terminates in a circular portion 49, while the third straight portion 50 extends to a point of the branch; wherein the fourth straight portion 53 and the fifth straight portion 52 extend from this point of the branch. The fourth and fifth rectilinear sections have unequal areas and terminate in circular sections 54 and 51, respectively. Likewise, the sixth straight portion 41 and the seventh straight portion 43 are branched from the second end of the first straight portion. The sixth straight portion 41 ends at a circular portion 42, and the seventh straight portion 43 extends to a point of the branch; wherein the eighth straight portion 46 and the ninth straight portion 44 extend from the point of the branch, the eighth and ninth rectilinear portions have unequal areas and terminate in circular portions 45 and 47 respectively.

In another aspect, the invention provides a process for the manufacture of drawn yarns and partially oriented yarns (POY) having improved filament cross-sections according to the invention. Generally, the process involves extruding a polyamide melt, typically 40 to 60 RV (according to the formic acid process), and preferably 48 to 52 RV, nylon 66 or nylon 6, to form shaped filaments. The spinneret according to the invention is maintained at a selected range of 245°C to 295°C, preferably at 280°C. The plurality of filaments extruded through the spinneret are cooled in a cross air flow to form solid filaments. These filaments may be treated with oil, converged, entangled and drawn, or left undrawn, before being wound into multifilaments at speeds greater than 3000 meters per minute (m/min).

Referring now to the schematic diagram of the process shown in Figure 5, a drawn yarn is produced by path A. Molten polymer 10 , polyamide, is pumped into spin pack 20 and pressed through a spinnerette to form filaments 40 . The extruded filaments are cooled by a transverse air flow 50 having an air velocity of about 0.15 to 0.5 m/min. The cooled filaments are converged into yarn 60 and an oil and water finish is preferably applied at 70 to the resulting bundle of yarns. Yarn 60 is advanced through first air-jet interlacing nozzle 80 to become interlaced yarn 90 . Yarn 90 proceeds to first godet roll 92 (feed roll) and associated breakaway roll, makes several turns to prevent slippage, and then to second godet roll 94 (draw roll) and associated breakaway roll. The stretch roll 94 moves at a surface speed greater than that of the feed roll 92 by 60 to 100%, preferably 80%. The bundle of yarns is thus preferably drawn (elongated) by an overall factor of about 1.8, reducing the denier of the overall yarns to form yarn 100. The drawn yarn 100 is preferably processed by a relaxation device 110 to adjust the stretch and relax the yarn as is conventionally practiced in the art. Any known relaxation device may be used including steam, heated fluid, heat pipes, heat blocks, heated rollers. The relaxed yarn bundle 120 optionally passes through the second interlacing nozzle 130 and is wound on the bobbin 150 at a winding speed of greater than 3000 m/min, more preferably about 3800 m/min, with the relaxed yarn 140 Optional ground oil treatment before. The obtained drawn yarn has an elongation of 25 to 45%, preferably 40 to 45%, and a tenacity of 35 to 45 cN/tex.

In addition, referring to the process schematic diagram in Figure 5, partially oriented yarn (POY) is produced by route B. Molten polymer 10 , polyamide, is pumped into spin pack 20 and pressed through a spinnerette to form filaments 40 . The exiting filaments are cooled by a transverse air flow 50 having an air velocity of about 0.15 to 0.5 m/min. The cooled filaments are converged into yarn 60 and an oil and water finish is preferably applied at 70 to the resulting bundle of yarns. Yarn 60 advances through a steam gas containing interfloor tube 75 as is known in the art. The steam treated yarns 85 intermingle at 80 and are partially wrapped around godet rolls 82 and 84, which control any winding tension changes to which the yarns are subjected. Yarn 115 is wound as a yarn package on bobbin 160 at a speed of about 3800 m/min. The POY produced preferably has an elongation of 55 to 85%, more preferably 75%, and a strength of 25 to 40 cN/tex, preferably 30 cN/tex.

Brief description of the drawings

Figure 1 shows a cross-section perpendicular to the longitudinal axis of a filament with preferred cross-sectional shape, showing dimensions R, F and D, rays R1, R2, reference point C, tangent reference line R3 and angle α;

Figure 2 is a cross-section perpendicular to the longitudinal axis of two adjacent filaments of the present invention;

Fig. 3 a is the plan view (to scale) of two section spinneret capillary cross-sectional shapes according to the present invention;

Fig. 3 b is a plan view (to scale) of a section of spinneret capillary cross-sectional shape according to the present invention;

Figure 4a is a photomicrograph of a yarn bundle comprising a yarn cross-section of 26 filaments produced by melt spinning from the spinneret capillary cross-sectional shape of Figure 3a according to the present invention;

Figure 4b is a photomicrograph of a yarn bundle comprising a yarn cross section of 26 filaments produced by melt spinning from the spinneret capillary cross section shape of Figure 3b according to the present invention;

Figure 5 is a schematic diagram of the equipment used to achieve the fully drawn yarn (A) and POY (B) spinning process according to the present invention.

Test Methods

Water absorption test method: The principle of the method is to hang a fabric strip vertically and immerse it in water with its lower end. The height the water rises to the fabric is measured at regular intervals. The fabric samples used were 300mm long and 25mm wide. The samples were conditioned for 16 hours at a relative humidity of 85% +/- 5% and a temperature of 20°C +/- 2°C. The maximum rise in water at 20°C +/- 2°C was measured after 2 minutes. The height is measured from the surface of the water to the point of maximum water rise on the fabric. The average of 3 measurements is recorded for each perpendicular fabric direction.

Fabric thickness test method: Fabric thickness is the average distance between the upper surface and the lower surface of the tested material under a certain pressure. The fabric samples were treated under the same conditions as the water absorption test. The measuring device used was a Shirley thickness gauge with a 50 cm ² presser foot. Make the presser foot drop onto the fabric under its own momentum. Measurements were repeated 10 times and mean and standard deviations were recorded to the nearest 0.05 mm.

example

Example 1

A first multifilament yarn of 96 dtex and 26 filaments (yarn 1A) was spun into POY using the apparatus shown schematically in Figure 5 and a spinneret according to Figure 3a with two segmented capillaries.

Nylon 66 polymer chips of 49.4 RV obtained by the formic acid process were melted in 10 and extruded through filter pack 20 and passed through a spinneret of 26 capillaries having the segmental cross-sectional shape shown in Figure 3a at a spinning temperature of 280°C 30.

Next, the extruded filaments 40 were cooled by a transverse air flow 50 at a velocity of 0.45 m/min. The cooling air is directed in the manner of Fig. 3a so as to first encounter the opposing convex portions 38 of the two capillary sections. The cooled filaments 60 are converged into yarns at 70 and oil and water treatment agents are applied to the resulting bundle of yarns at 70 . The converging yarns to which the treatment agent is applied proceed along line B in FIG. 5 . The yarn is conveyed through a steam environment containing interfloor tubes 75. The steamed yarn 85 is entangled by the device 80 . The entangled yarn 115 is wound on the bobbin 160 to form a yarn package at a speed of 3800 m/min.

The POY produced in this way has a yarn linear density of 96 dtex, an elongation at break of about 75% and a tenacity of 30 cN/tex. The cross-section of the yarn is shown in Figure 4a.

A second multifilament partially oriented yarn of 96 dtex and 26 filaments (yarn 1B) was spun exactly as the first POY using the apparatus shown in Figure 5. For yarn 1B a spinneret with capillaries according to Fig. 3b was used. The elongation and strength properties are the same as the first POY. The cross-section of yarn 1B is shown in Figure 4b.

A comparative multifilament yarn of 96 dtex and 26 filaments (yarn 1C) was spun in exactly the same way as the first yarn, except that the spinneret was replaced with a 26" Circular cross-section" shaped capillary.

All samples, 1A and 1B (yarns of the invention) and 1C (a circular cross-section comparative yarn) were 8 ply each and were subsequently air jet texturized (AJT) using a HEBERLEIN HEMAJET (registered trademark) to become Textured yarn of 730 cents by 208 filaments (8×26 filaments). These textured yarns were 2-ply and knitted into a "furrow" and tested for thermal conductivity.

The heat conduction test method is basically the method of ASTM D1518-85 (re-approved in 1990). This method measures the time rating of heat transfer from a warm, dry, constant temperature, horizontal panel up through a layer of knitted furrow test material to a relatively calm, cool environment. Measure thermal resistance and calculate thermal insulation value or CLO value. "CLO" is a unit of "cloth heat resistance" in ASTM D1518 and is equal to 0.155 (°Cm ² W ^-1 ). The base temperature was 25°C (T ₁ ) and the head plate temperature was 35°C (T ₂ ). A minimum pressure of 260 Nm ^-2 is applied to the furrow knitted fabric during the test procedure. Each sample was tested 3 times and the average results are given, which are reported in Table 1 below.

The test results reported in Table 1 show a 13-15% increase in thermal resistance of yarns with preferred open hollow cross-sections relative to circular cross-sections in a knitted construction. Similarly, preferred open hollow cross-sections in knitted constructions increase the CLO value by 13-15% relative to circular cross-section yarns. Clearly, the tested open hollow filament yarn of the knitted construction is a better thermal insulator than the round filament yarn.

Table 1 Yarns used in furrow knitting Thermal resistance m ² ℃W ^-1 ×(10 ³ ) CLO value m ² ℃W ^-1 /(0.155) ASTM D1518-85 Inventive cross-section of yarn 1A (2x730f208) using two-stage spinneret 103.7 0.67 Yarn 1B (2x730f208) uses an inventive cross-section of a spinneret 105.0 0.68 Yarn 1C (2x730f208) "round" cross section 91.5 0.59

Example 2

POY samples from Example 1, Yarn 1A and Comparative Yarn 1C, both spun to 96 dtex and 26 filaments, were false twisted (FTT) on a DCS1200 texturing machine at a speed of 600 m/min. . The primary heating element of the deformation machine is 220°C, and the secondary heating element is not used. A stretch-textured yarn of 78 dtex and 26 filaments (78f26) was prepared with a 6 mm solid ceramic disc configured as a 1/7/1 smooth/working/smooth texturing machine. The 78f26 yarn was circular knitted into a 28-needle jersey interlock fabric, washed, dyed and heat-set. Fabric samples of 300 mm x 25 mm were used for the water absorption test. The samples were hung vertically in a water bath and the vertical rise of water was measured after 2 minutes. The average of 3 samples is given in Table 2. Fabrics formed from yarns of filaments having the preferred cross-section demonstrated better water absorption than fabrics of the same construction formed from yarns of circular filament cross-section. This advantage is at least a 2-fold improvement in water absorption performance.

Table 2 Textured yarns used in circular knits Vertical rise in mm (fabric along the longest direction) Vertical rise in mm (fabric along the shortest direction) 78f26 compares circular cross section 1.5 0 (Yarn 1C) False twist textured yarn 78f26 cross section of the present invention (yarn 3.7 2.7 Line 1A) False twist textured yarn

Example 3

A drawn yarn of 192 dtex and 52 filaments was spun with the apparatus of Figure 5 and using a spinneret of 52 capillaries having the cross-sectional shape of Figure 3a. Nylon 66 polymer of 49.4 RV (made by the formic acid process) was melted in 10 and extruded through a polymer filter pack 20 and then through a spinneret 30 maintained at a spinning temperature of 280°C. The extruded filaments 40 were cooled by a transverse air flow 50 at a velocity of 0.4 m/min. The transverse air flow 50 is directed to first encounter the facing raised portion 38 of the two-segment capillary as in Figure 3a. The cooled filaments are converged into a yarn bundle 60 with the application of oil and water and proceed along another path A. The yarns are entangled with air jets 80 as commonly used in the art. The entangled yarn 90 is then delivered to a second godet roll 94 and associated breakaway roll (drawing roll) via a feed roll 92 and an associated breakaway roll (wrapped around the roll several times to prevent slipping). Run at a surface speed that is 80% greater than the surface speed of the feed roll 92 . The entangled yarn bundle 90 is drawn by a total factor of 1.8, reducing the overall yarn denier. The drawn yarn 100 is processed through a steam injection device 110 to set the stretch and relax the yarn. The relaxed yarn bundle 120 passes through the second interlacing jet 130 and then the yarn 140 is wound onto the bobbin 150 at a speed of 3800 m/min. This process provided a fully drawn yarn cake with a linear yarn density of 192 dtex, an elongation at break of 42.8%, and a tenacity of 41 cN/tex. The yarn in dry form had a RV of 50.3 from the formic acid method. The filaments of this 52 filament yarn have a cross-sectional shape perpendicular to the longitudinal axis which is substantially similar to the filaments shown in Figure 4a.

This yarn, Yarn 3A, was used as the weft yarn for the woven fabric in a 3/1 twill weave, and the warp yarn was 78 decitex (51 round filaments). A detailed description of the weaving process and fabric processing is given in Table 3. As a comparative example, a fully drawn yarn of 192 dtex and 52 filaments was spun exactly as described above, but using a spinnerette with "circular cross-section" capillaries, which The yarn is referred to as yarn 3B. A second fabric sample was woven as described above using yarn 3B as the weft yarn. A detailed description of the weaving process and fabric processing is given in Table 3. Both fabrics were processed in the same greige, dyed and heat-set manner. Ten 75 mm2 samples were cut from each fabric specimen (grey, dyed and heat set). The samples were measured for fabric thickness in the same manner using a micrometer. The results of the fabric thickness measurements (average of 10 measurements) are given in Table 3. A fabric comprising filaments of preferred cross-section as weft yarns is thicker than a fabric woven entirely of filaments of circular cross-section as warp and weft yarns. Thus, a woven fabric having filaments of preferred cross-section as weft yarns provides a lower density fabric that is lightweight and aesthetically pleasing.

table 3 gray fabric gray fabric dyed fabric dyed fabric heat set fabric heat set fabric Yarn 3B Yarn 3A Yarn 3B Yarn 3A Yarn 3B Yarn 3A per cm warp x per cm weft 57.5x38.8 58.2x39.7 61.3x40 62.2x39.8 61.5x41 61.6x41 Woven fabric thickness mm 0.22 0.24 0.20 0.22 0.20 0.21

The foregoing embodiments have been described by way of example only. However, some other embodiments of filaments, yarns, spinnerets and processes according to the present invention will be apparent to the skilled reader.

Claims (38)

1. special-shaped polymer filaments, it has an open hollow shape of cross section perpendicular to the long filament longitudinal axis, and wherein the size of cross section prevents this long filament and the second long filament interlocking with identical cross-section.

2. special-shaped polymer filaments, it has an open hollow shape of cross section perpendicular to the long filament longitudinal axis, wherein near the zone of each end of cross section than the relief width between the described zone that limits the open hollow cross-sectional openings.

3. special-shaped polymer filaments according to claim 1 and 2, wherein cross section comprises an entity part, and a central hollow zone and feeds the opening in central hollow zone, and its split shed is facing to a radial angle less than 90 °.

4. special-shaped polymer filaments according to claim 3, wherein said opening is facing to a radial angle less than 90 °.

5. special-shaped polymer filaments according to claim 1 and 2, wherein cross section comprises an entity area, one central hollow zone, with the slot in a feeding central hollow zone, wherein the radial thickness of the entity part of the location filament cross of close this slot is greater than the average radial thickness of this entity area.

6. require described special-shaped polymer filaments according to arbitrary aforesaid right, wherein cross section comprises foundation and two lateral parts with first and second ends, and this lateral parts is extended by first and second ends of foundation with substantially parallel relation.

7. special-shaped polymer filaments according to claim 6, wherein said foundation and two curved shapes of lateral parts.

8. special-shaped polymer filaments, it has a shape of cross section perpendicular to the long filament longitudinal axis, described shape of cross section has a center arch section and first and second elongated component, each described component has near-end and distal portions, described proximal part is connected to described core and described distal portions is connected to the bottom on each component, described bottom has size F, described component and described center arch section limit an opening portion, and described base section leads to the slot of described opening portion with substantially parallel relation orientation and qualification; Described slot has dimension D, and wherein dimension D is less than size F.

9. require described special-shaped polymer filaments according to arbitrary aforesaid right, wherein polymer is a polyamide.

10. special-shaped polymer filaments according to claim 9, wherein polyamide polymer has according to the formic acid method greater than 40 relative viscosity.

11. special-shaped polymer filaments according to claim 10, wherein according to the relative viscosity of the polyamide of formic acid method in 46 to 56 scopes.

12. require described special-shaped polymer filaments according to arbitrary aforesaid right, wherein the long filament linear density is less than 20 dtexs.

13. require described special-shaped polymer filaments according to arbitrary aforesaid right, wherein the long filament linear density is less than 4 dtexs.

14. require described special-shaped polymer filaments according to arbitrary aforesaid right, wherein filament cross is along the filament length substantially constant.

15. require described special-shaped polymer filaments according to arbitrary aforesaid right, wherein select in the group of polymer by the copolymer of nylon 66 and nylon 6 and nylon 66 or nylon 6.

16. a polyfilament yarn, it comprises one of any special-shaped long filament of at least a portion claim 1-15.

17. polyfilament yarn according to claim 16, wherein yarn mainly is made up of open hollow long filament according to the present invention.

18. polyfilament yarn according to claim 16, wherein yarn is a kind of drawing.

19. polyfilament yarn according to claim 18, wherein yarn has about elongation at break of 20 to 50% and about intensity of 25 to 60cN/tex.

20. polyfilament yarn according to claim 16, wherein yarn is partially oriented yarn (POY).

21. polyfilament yarn according to claim 20, wherein yarn has about elongation at break of 55 to 85% and about intensity of 25 to 40cN/tex.

22. goods that comprise the polyfilament yarn of at least a portion claim 16.

23. goods according to claim 22, wherein goods comprise by the knitting or woven fabric that forms of described polyfilament yarn.

24. one kind is used for by polymer melt being extruded as the spinning head of long filament production according to one of any special-shaped open hollow long filament of claim 1 to 21, wherein said spinning head comprises a spinnerets with the upper and lower surface that is connected by the capillary set, with or (a) each capillary has the open hollow lateral cross section, or (b) each capillary comprises two adjacent sections, obtains the open hollow filament cross along the long filament longitudinal axis thus when from some between the molten polymer flow section of being incorporated in of each section.

25. spinning head according to claim 24, wherein: each capillary constitutes by two sections; Each section comprises a straightway part, and this straightway part has the connecting portion with a pair of projection in each end; At first end, this equates the projection area and comprises that respectively one ends in the straight line portion of circular portion; At the second end, this does not wait the projection area and comprises that respectively one ends in the straight line portion of circular portion.

26. spinning head according to claim 25, wherein each section is the mirror image of other section.

27. spinning head according to claim 26, wherein each section be other section can not overlapping mirror image.

28. spinning head according to claim 24, wherein capillary itself has an open hollow cross section, and the shape of cross section that each capillary had comprises:

First straight line portion, this straight line portion have relative first end and second end mutually;

From second straight line portion and the 3rd straight line portion that the first end branch of first comes out, wherein second straight line portion ends in a circular portion, and the 3rd straight line portion extends to first point of branch;

From described first extended the 4th straight line portion and the 5th straight line portion of branch, wherein the 4th and the 5th straight line portion has the area that does not wait and respectively ends in circular portion;

From the 6th straight line portion and the 7th straight line portion that the second end branch of first straight line portion comes out, wherein the 6th straight line portion ends in a circular portion, and the 7th straight line portion extends to second point of branch; With

From second extended the 8th straight line portion and the 9th straight line portion of branch, wherein the 8th and the 9th straight line portion has the area that does not wait, and each straight line portion ends in circular portion.

29. one kind is used to make the technology that has according to the drawing of one of any improvement filament cross of claim 1 to 21, this technology comprises: push a kind of polyamide melt through the spinning head one of any according to claim 24 to 28; The molten mass that squeezes out with horizontal air flow cooling forms the solid long filament; Selectively make chilled long filament through steam ambient, apply a kind of fibre finish, interwoven yarns selectively, allow yarn feeding roller and draw roll on process, the superficial velocity of described feeding roller and draw roll has the different of fixed amount, drawing handled to reduce final yarns shrink and obtain good yarn package and be shaped, selectively apply a kind of fibre finish, interwoven yarns and with speed winding filaments greater than 3000m/min.

30. one kind is used to make the technology that has according to the partially oriented yarn (POY) of one of any improvement filament cross of claim 1 to 21, this technology comprises: push a kind of polyamide melt through the spinning head one of any according to claim 24 to 28; The molten mass that squeezes out with horizontal air flow cooling forms the solid long filament; Selectively make chilled long filament through steam ambient, apply a kind of fibre finish, selectively make yarn process on tension control roll, selectively interwoven yarns and with speed winding filaments greater than 3000m/min.

31. according to claim 29 or 30 described technologies, wherein polymer is a kind of polyamide with measurement 40 to 60RV in the formic acid.

32. according to claim 29 or 30 described technologies, wherein the spinning head temperature is about 245 ℃ to 295 ℃.

33. according to one of any described technology of claim 29 to 32, wherein laterally the speed of air flow is about 0.15 to 0.5 meter/minute.

34. according to claim 29,31,32 or 33 one of any described technologies, the long filament that wherein is cooled is further processed as follows before reeling: chilled long filament is converged to yarn beam; Yarn beam is sent to first draw-off godet (feeding roller) and second spinning reel subsequently (94) (draw roll), wherein second spinning reel be with greater than the superficial velocity operation of the superficial velocity 10 to 100% of feeding roller with drawing and reduce whole denier count as received thus; The yarn that heat treatment has stretched stretch with typing and lax yarn so that a kind of drawing to be provided.

35. according to one of any described technology of claim 30 to 33, wherein chilled long filament is further processed as follows before reeling: chilled long filament is converged to yarn; The yarn of being assembled sent the steam ambient that contains the interlayer pipe; The yarn of steam treatment is entwined and is reeled so that a kind of partially oriented yarn (POY) to be provided.

36. one kind by the multifilament air jet texturing yarn of producing according to the described drawing of claim 18.

37. one kind by the multifilament air jet texturing yarn according to the described partially oriented yarn production of claim 20.

38. multifilament false twist texturing (FTT) yarn according to the described partially oriented yarn production of claim 20.

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