Spinneret, asymmetric double hollow curled polyester and preparation method thereof

Abstract

The present invention relates to a spinneret, an asymmetric double hollow curly polyester and a preparation method thereof. The spinneret comprises a spinneret body and a plurality of spinneret holes formed on the spinneret body. The spinneret holes are of a "9"-shaped structure. The spinneret is used to prepare an asymmetric double hollow curly polyester with a bamboo-like shape by utilizing the difference in the hole expansion effect and the shear rate. That is, a linen-like polyester that integrates the characteristics of special shape, hollowness and curlyness has a high strip unevenness rate. When heated, a curly shape is generated, and a capillary phenomenon can be generated. At the same time, the surface area of ​​the polyester is increased, so that the prepared fabric has a fluffy feeling, improves the gloss effect and hand feel, improves the air permeability of the fabric, and greatly improves the application range of FDY. In addition, the asymmetric double hollow curly polyester has a hollow structure, so that there is a continuous cavity inside the polyester, which reduces the mass of the polyester and improves the lightweight degree of the fabric.

Description

Technical Field

[0001] The invention relates to a spinneret, asymmetric double hollow curled polyester and a preparation method thereof, and belongs to the field of polyester fibers. Background Art

[0002] Hemp is an important natural fiber, known as "Chinese grass". my country is the main production area. Due to the unevenness of hemp fibers, hemp fabrics are extremely breathable, smooth to the touch, fast in absorbing and releasing moisture, and have a rough and unique fabric style. However, due to the high degree of crystallinity of hemp fibers, although it is strong, it is not soft enough, so the fabric feels hard. Polyester is not only strong, elastic, flexible and easy to dry, the fabric does not need to be ironed, and the price of polyester staple fiber is only one-fourth of that of hemp. If polyester and hemp are blended, the resulting fabric is crisp, refreshing, strong, easy to dry, and does not need to be ironed. Combining the advantages of the two fibers, it is an ideal textile material. Therefore, imitation hemp polyester materials are gradually being valued.

[0003] Linen-like polyester fabric is a fabric obtained by replacing natural linen with chemical fiber polyester. This kind of fabric not only has the rough and skeletal surface style of linen and the excellent performance of moisture absorption and breathability, but also eliminates the roughness and wrinkle-proneness of linen fabric when worn. Bamboo is one of the main characteristics of linen-like polyester. Due to the difference in structure, the heat shrinkage and elongation of thick sections are higher than those of fine sections. When dyeing, thick sections will absorb more dyes than fine sections, making the silk strips show alternating color changes of dark dyeing and light dyeing. These characteristics of linen-like polyester make it have excellent development performance in textile processing. The linen-like polyester fabric spun by linen-like polyester is smooth and breathable, and has the soft color, dry feel and drape of natural fiber fabrics. The product is very popular in the market.

[0004] At present, the main methods for imitating linen polyester include polyester-linen blending, composite deformation processing, uneven stretching, etc., but the fiber unevenness obtained by polyester-linen blending is relatively low, and the technical difficulty of composite deformation processing and uneven stretching is relatively high, making it difficult to mass produce linen-like polyester. Therefore, it is necessary to find a simpler method to prepare linen-like polyester. Summary of the invention

[0005] The object of the present invention is to provide a spinneret, an asymmetric double hollow curly polyester and a preparation method thereof. A spinneret having a spinneret hole of a "9"-shaped structure is used and the asymmetric double hollow curly polyester with a bamboo-node morphology is prepared by utilizing the hole expansion effect and the difference in shear rate. The spinneret has a high unevenness rate and the preparation method is simple.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a spinneret for preparing asymmetric double hollow curly polyester, the spinneret comprising a spinneret body and a plurality of spinneret holes formed on the spinneret body, the spinneret holes being of a "9"-shaped structure, the spinneret holes comprising a first arc-shaped long hole, a second arc-shaped long hole and a third arc-shaped long hole which are not connected to each other and are arranged in sequence, the first arc-shaped long hole, the second arc-shaped long hole and the third arc-shaped long hole are all of a "C"-shaped structure, and the first arc-shaped long hole and the second arc-shaped long hole have the same orientation, and the second arc-shaped long hole and the third arc-shaped long hole have opposite orientations.

[0007] Further, the central angle of the first arc-shaped long hole is 200°-205°, the diameter of the outer ring is 0.50-0.51mm, and the diameter of the inner ring is 0.39-0.40mm; the central angle of the second arc-shaped long hole is 180°-190°, the diameter of the outer ring is 0.65-0.66mm, and the diameter of the inner ring is 0.52-0.53mm; the central angle of the third arc-shaped long hole is 120°-130°, the diameter of the outer ring is 0.88-0.90mm, and the diameter of the inner ring is 0.60-0.62mm, wherein the outer ring and the inner ring are respectively the outer ring and the inner ring of the corresponding arc-shaped long hole.

[0008] Furthermore, the vertical spacing between the upper break and the lower break of the first arc-shaped long hole is 0.04-0.05mm; the vertical spacing between the upper break and the lower break of the second arc-shaped long hole is 0.07-0.08mm; the vertical spacing between the upper break and the lower break of the third arc-shaped long hole is 0.15-0.16mm, wherein the upper break and the lower break are the intersection points of the straight line where the break is located and the outer ring and the inner ring respectively.

[0009] Furthermore, the shortest distance between the first arc-shaped long hole and the second arc-shaped long hole is 0.07-0.08 mm; the shortest distance between the second arc-shaped long hole and the third arc-shaped long hole is 0.08-0.09 mm.

[0010] The present invention also provides a method for preparing asymmetric double hollow curly polyester, using the spinneret as described above and adopting the FDY process to meter, extrude, cool, oil, stretch, heat-set and wind the polyester melt to obtain the asymmetric double hollow curly polyester.

[0011] Furthermore, the parameters of the FDY process are:

[0012] Spinning temperature: 280℃-290℃;

[0013] Cooling temperature: 20℃-25℃;

[0014] Network pressure: 0.20MPa-0.30MPa;

[0015] One roller speed: 1500m / min-1700m / min;

[0016] First roller temperature: 80℃-85℃;

[0017] Second roller speed: 3700m / min-3800m / min;

[0018] Second roller temperature: 105℃-115℃;

[0019] Winding speed: 3650m / min-3740m / min.

[0020] The present invention also provides an asymmetric double hollow curly polyester, which is prepared by the preparation method of the asymmetric double hollow curly polyester as described above. The cross-section of the asymmetric double hollow curly polyester is a "9"-shaped asymmetric double hollow structure. The CV value of the asymmetric double hollow curly polyester is 4.5-6.0%, and the U value of the strip unevenness is 3.0-6.5%.

[0021] Furthermore, the asymmetric double hollow curled polyester monofilament has a fineness of 4.5-7.0 dtex.

[0022] Furthermore, the asymmetric double hollow curly polyester has a fineness of 80-170 dtex, a breaking strength of ≥3.1 cN / dtex, a breaking elongation of 45.0±6.0%, a boiling water shrinkage of 10.0-15.0%, an oil content of 0.90±0.20%, and a hollowness of 5-10%.

[0023] The beneficial effects of the present invention are as follows: the spinneret holes of the spinneret are of a "9"-shaped structure, and the spinneret is used to prepare an asymmetric double hollow curly polyester with a bamboo-like shape by utilizing the hole expansion effect and the difference in shear rate, that is, a linen-like polyester that integrates the characteristics of special shape, hollowness, and curliness, which has a high unevenness of the strips, and when heated, a curly shape will be generated, which can produce a capillary phenomenon, and at the same time increase the surface area of ​​the polyester, so that the prepared fabric has a fluffy feeling, improves the gloss effect and feel, improves the air permeability of the fabric, and greatly improves the application range of FDY. In addition, the asymmetric double hollow curly polyester has a hollow structure, so that there is a continuous cavity inside the polyester, which reduces the mass of the polyester and improves the lightweight degree of the fabric.

[0024] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1It is a schematic structural diagram of the spinneret hole shown in the present invention.

[0026] Figure 2 It is a partial structural schematic diagram of the spinneret hole shown in the present invention.

[0027] Figure 3 Another schematic structural diagram of the spinneret hole shown in the present invention.

[0028] Figure 4 This is a schematic diagram of the cross-sectional structure of the asymmetric double hollow curled polyester prepared by the present invention. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] See also Figure 1 The present invention provides a spinneret for preparing asymmetric double hollow curly polyester, the spinneret comprising a spinneret body and a plurality of spinneret holes formed on the spinneret body. The specific number and arrangement of the spinneret holes are not specifically limited here, and can be set according to actual needs. In addition, the structure of the spinneret is the prior art, and the difference lies in the structure of the spinneret holes, which will not be described in detail here.

[0032] In this embodiment, the spinneret hole is a "9"-shaped structure, and the spinneret hole includes a first arc-shaped long hole 1, a second arc-shaped long hole 2, and a third arc-shaped long hole 3 that are not connected to each other and arranged in sequence. The first arc-shaped long hole 1, the second arc-shaped long hole 2, and the third arc-shaped long hole are all "C"-shaped structures, and the first arc-shaped long hole 1 and the second arc-shaped long hole 2 have the same orientation, and the second arc-shaped long hole 2 and the third arc-shaped long hole 3 have opposite orientations, that is, the second arc-shaped long hole 2 and the third arc-shaped long hole 3 are arranged oppositely.

[0033] The center angle of the first arc-shaped long hole 1 is 200°-205°, the diameter of the outer ring is 0.50-0.51mm, and the diameter of the inner ring is 0.39-0.40mm; the center angle of the second arc-shaped long hole 2 is 180°-190°, the diameter of the outer ring is 0.65-0.66mm, and the diameter of the inner ring is 0.52-0.53mm; the center angle of the third arc-shaped long hole 3 is 120°-130°, the diameter of the outer ring is 0.88-0.90mm, and the diameter of the inner ring is 0.60-0.62mm. The outer ring and the inner ring are respectively the outer ring and the inner ring of the corresponding arc-shaped long hole.

[0034] Specifically, the first arc-shaped slot 1 includes a first outer ring 11, a first inner ring 12, and two first breaks 13 connecting the first outer ring 11 and the first inner ring 12. The two first breaks 13 are arranged on both sides opposite to each other, the diameter of the first outer ring 11 is 0.50-0.51 mm, the diameter of the first inner ring 12 is 0.39-0.40 mm, and the size of the first outer ring 11 is larger than that of the first inner ring 12.

[0035] The second arc-shaped long hole 2 includes a second outer ring 21, a second inner ring 22, and two second breaks 23 connecting the second outer ring 21 and the second inner ring 22. The two second breaks 23 are arranged on both sides opposite to each other, the diameter of the second outer ring 21 is 0.65-0.66 mm, the diameter of the second inner ring 22 is 0.52-0.53 mm, and the size of the second outer ring 21 is larger than that of the second inner ring 22.

[0036] The third arc-shaped long hole 3 includes a third outer ring 31, a third inner ring 32, and two third breaks 33 connecting the third outer ring 31 and the third inner ring 32. The two third breaks 33 are arranged on both sides opposite to each other, the diameter of the third outer ring 31 is 0.88-0.90 mm, the diameter of the third inner ring 32 is 0.60-0.62 mm, and the size of the third outer ring 31 is larger than that of the third inner ring 32.

[0037] It is worth noting that the above numerical values ​​include all values ​​of lower and upper values ​​increased by one unit from the lower limit to the upper limit, and there is a gap of at least two units between any lower value and any higher value.

[0038] For example, the central angle of the first arc-shaped long hole 1 is 200°-205°, preferably 201°-204°, and more preferably 202°-203°, in order to illustrate the values ​​not explicitly listed above, such as 201.5°, 202.5°, 203.5°, etc.

[0039] As mentioned above, the example range with 1° as the interval unit does not exclude the increase of the numerical unit with appropriate units such as 0.5°, 2°, etc. These are just examples intended to be clearly expressed, and it can be considered that all possible combinations of numerical values ​​listed between the lowest value and the highest value are clearly stated in this specification in a similar manner.

[0040] Unless otherwise specified, all ranges include endpoints and all numbers between the endpoints. For other limiting descriptions of numerical ranges appearing in this article, please refer to the above description and will not be repeated here.

[0041] See also Figure 2 , the vertical spacing between the upper and lower fractures of the first arc-shaped long hole 1 is 0.04-0.05mm; the vertical spacing between the upper and lower fractures of the second arc-shaped long hole 2 is 0.07-0.08mm; the vertical spacing between the upper and lower fractures of the third arc-shaped long hole 3 is 0.15-0.16mm, wherein the upper fracture and the lower fracture are the intersections of the straight line where the fracture is located and the outer ring and the inner ring, respectively. Specifically, the upper fracture and the lower fracture of the first arc-shaped long hole 1 are respectively as follows Figure 2 As shown in A and B in FIG. 1 , the upper fracture and the lower fracture of the second arc-shaped slot 2 are respectively as shown in FIG. Figure 2 As shown in C and D in FIG. 1 , the upper fracture and the lower fracture of the third arc-shaped slot 3 are respectively as shown in FIG. Figure 2 As shown in E and F.

[0042] See also Figure 3 The vertical distance between the upper and lower fractures of the first arc-shaped slot 1 is as follows: Figure 3 As shown in a, the vertical distance between the upper and lower fractures of the second arc-shaped slot 2 is as follows: Figure 3 As shown in b, the vertical distance between the upper and lower fractures of the third arc-shaped slot 3 is as follows: Figure 3 As shown in c.

[0043] The shortest distance between the first arc-shaped long hole 1 and the second arc-shaped long hole 2 is 0.07-0.08 mm, and the shortest distance between the second arc-shaped long hole 2 and the third arc-shaped long hole 3 is 0.08-0.09 mm. That is, the first arc-shaped long hole 1, the second arc-shaped long hole 2 and the third arc-shaped long hole 3 are arranged relatively close to each other.

[0044] The present invention also provides a method for preparing asymmetric double hollow curly polyester, using the spinneret as shown above and adopting the FDY process to meter, extrude, cool, oil, stretch, heat-set and wind the polyester melt to obtain the asymmetric double hollow curly polyester.

[0045] The FDY process is a prior art and will not be described in detail herein. The parameters of the FDY process are:

[0046] Spinning temperature: 280℃-290℃;

[0047] Cooling temperature: 20℃-25℃;

[0048] Network pressure: 0.20MPa-0.30MPa;

[0049] One roller speed: 1500m / min-1700m / min;

[0050] First roller temperature: 80℃-85℃;

[0051] Second roller speed: 3700m / min-3800m / min;

[0052] Second roller temperature: 105℃-115℃;

[0053] Winding speed: 3650m / min-3740m / min.

[0054] Polyester melt and other polymers have a swelling effect when they are ejected from the spinneret, that is, the polymer will expand. The swelling phenomenon of polymers is closely related to the diameter or area of ​​the spinneret. Under a certain temperature, a certain shear rate and the same spinneret length, the extrusion swelling phenomenon of melts with different intrinsic viscosities has a certain relationship with the diameter or area of ​​the spinneret. The smaller the diameter or area of ​​the spinneret, the more serious the extrusion swelling phenomenon of the melt. The larger the diameter or area of ​​the spinneret, the more obvious the swelling phenomenon can be.

[0055] Linen-like polyester is prepared by changing the shape and distribution of the spinneret holes of the spinneret plate. The spinneret holes are made into a plurality of discontinuous arc-shaped long holes close to each other, and the expansion effect of the melt when it is extruded from the spinneret holes is utilized to make the melt streams adhere to each other to form special-shaped fibers.

[0056] The spinneret of this embodiment is composed of three discontinuous arc-shaped long holes, including the first arc-shaped long hole 1, the second arc-shaped long hole 2 and the third arc-shaped long hole 3. The first arc-shaped long hole 1, the second arc-shaped long hole 2 and the third arc-shaped long hole 3 are grouped as a group, which are respectively viscous flow No. 1, viscous flow No. 2 and viscous flow No. 3. The areas of the three arc-shaped long holes are S1, S2 and S3, respectively, where S1<S2<S3. The areas of the three arc-shaped long holes are different, and the shear rates through each arc-shaped long hole are different.

[0057] Specifically, under the same melt, spinning process conditions and spinneret hole length, the shear rate decreases with the increase of the arc-shaped long hole area. The spinneret hole length is the length of the first arc-shaped long hole 1, the second arc-shaped long hole 2 and the third arc-shaped long hole 3 along the vertical direction. Figure 1 The length in the direction of the plane shown.

[0058] γ=(n+3)BQ / (2A 2 )

[0059] Where γ is the shear rate, B is the perimeter of the shaped hole, Q is the volume flow rate, A is the area of ​​the shaped hole, and n is the rheological index.

[0060] The shear rates of the melt passing through the three arc-shaped long holes are γ1, γ2, and γ3, respectively, and γ1>γ2>γ3. At the same time, due to the expansion effect, the three melt streams will adhere to each other, and the orifice expansion ratio (the ratio of the equilibrium cross-sectional area of ​​the extrudate to the cross-sectional area of ​​the die) will increase with the increase of the shear rate, resulting in the orifice expansion ratios of the No. 1, No. 2, and No. 3 streams decreasing in sequence.

[0061] There are two types of viscosity, namely, viscous force: ① molecular viscosity, which reflects the momentum transport effect during molecular motion; ② turbulent viscosity, which reflects the effect of turbulent motion on momentum transport. Since both viscous flow No. 1 and viscous flow No. 2 are polyester melts, the shear rate and shear stress of viscous flow No. 1 in the monomer volume are greater than the shear rate and shear stress of viscous flow No. 2. Therefore, the viscosity and friction between viscous flow No. 1 and viscous flow No. 2 in the unit volume are greater than the viscosity and friction of viscous flow No. 2 itself. Therefore, viscous flow No. 2 will adhere to viscous flow No. 1 with a higher shear rate and flow beyond its own shear rate, which makes the tensile stress of viscous flow No. 2 exceed its own tensile strength, causing turbulence in the viscous flow and a small section of viscous flow No. 2 to adhere to viscous flow No. 1.

[0062] Similarly, the No. 3 viscous flow will also attach to the No. 2 viscous flow, and then produce the viscous flow turbulence phenomenon. The result of the viscous flow turbulence phenomenon is that the thickness of the melt changes. After stretching and cooling to form fibers, an uneven structure similar to hemp fibers will be produced. At the same time, another result of the viscous flow turbulence phenomenon is that the stress on the fiber axis is uneven, the coarse fiber part has a small stress, while the fine fiber part has a large stress. When the fiber is heated, the fiber shrinks unevenly, causing the fiber to curl, which can produce capillary phenomena and increase the surface area of ​​the fiber, improve the hygroscopicity and water absorption of the fabric, and greatly expand the application range of FDY.

[0063] The U% or CV% value of the unevenness of the fiber length and short segments reflects the unevenness of the fiber length. It reflects the uniformity of the FDY length to a certain extent, and has a significant impact on the dyeing properties of the final product of FDY. It may show significant uneven dyeing on the fabric, with dark dyeing on the coarse fiber part and light dyeing on the fine fiber part. The surface of the fabric shows the uneven dyeing of the hemp fiber fabric in the form of dots. This makes the imitation hemp fabric have a rough and bony surface style and moisture-absorbing and breathable fabric properties. At the same time, the imitation hemp fabric has good shape retention and anti-wrinkle properties, overcoming the shortcomings of traditional pure hemp fabrics such as itching and easy wrinkling.

[0064] See also Figure 4The present invention also provides an asymmetric double hollow curly polyester, which is prepared by the preparation method of the asymmetric double hollow curly polyester as shown above. An asymmetric double hollow curly polyester with a bamboo-like morphology is prepared using a special spinneret and utilizing the difference in the hole expansion effect and the shear rate, that is, a linen-like polyester that integrates the characteristics of special shape, hollowness, and curliness. It has a higher strip unevenness rate. Specifically, the strip unevenness rate CV value is 4.5-6.0%, and the strip unevenness rate U value is 3.0-6.5%. Compared with the conventional FDY, the strip unevenness rate CV value is 0.7-1.1%, and the strip unevenness rate U value is 0.8-1.5%. The asymmetric double hollow curly polyester obtained by the present invention has the style of linen-like fabric.

[0065] The asymmetric double hollow crimped polyester monofilament has a fineness of 4.5-7.0 dtex and excellent performance. The asymmetric double hollow crimped polyester has a fineness of 80-170 dtex, a breaking strength of ≥3.1 cN / dtex, a breaking elongation of 45.0±6.0%, a boiling water shrinkage of 10.0-15.0%, an oil content of 0.90±0.20%, and a hollowness of 5-10%.

[0066] When heated, the asymmetric double hollow curled polyester will produce a curled shape, which can produce capillary phenomena and increase the surface area of ​​the polyester, making the prepared fabric fluffy, improving the gloss effect and feel, and increasing the air permeability of the fabric, greatly expanding the application range of FDY. Its cross-section is a "9"-shaped asymmetric double hollow structure, which makes the polyester have a continuous cavity inside, reduces the weight of the polyester, and increases the lightweight degree of the fabric.

[0067] The above preparation method is described in detail below with reference to specific examples.

[0068] Embodiment 1

[0069] The center angle of the first arc-shaped long hole of the spinneret is 200°, the diameter of the outer ring is 0.50mm, and the diameter of the inner ring is 0.39mm; the center angle of the second arc-shaped long hole is 180°, the diameter of the outer ring is 0.65mm, and the diameter of the inner ring is 0.52mm; the center angle of the third arc-shaped long hole is 120°, the diameter of the outer ring is 0.88mm, and the diameter of the inner ring is 0.60mm. The vertical spacing between the upper and lower fractures of the first arc-shaped long hole is 0.04mm; the vertical spacing between the upper and lower fractures of the second arc-shaped long hole is 0.07mm; the vertical spacing between the upper and lower fractures of the third arc-shaped long hole is 0.15mm. The shortest distance between the first arc-shaped long hole and the second arc-shaped long hole is 0.07mm; the shortest distance between the second arc-shaped long hole and the third arc-shaped long hole is 0.08mm.

[0070] The spinneret is used to prepare asymmetric double hollow curly polyester by adopting FDY process, through metering, extrusion, cooling, oiling, stretching, heat setting and winding of polyester melt.

[0071] The parameters of the FDY process are:

[0072] Spinning temperature: 280℃;

[0073] Cooling temperature: 20℃;

[0074] Network pressure: 0.20MPa;

[0075] One roller speed: 1500m / min;

[0076] First roller temperature: 80℃;

[0077] Second roller speed: 3700m / min;

[0078] Second roller temperature: 105℃;

[0079] Winding speed: 3650m / min.

[0080] The asymmetric double hollow curly polyester obtained by the above steps has a CV value of 6.0% and a U value of 6.5%, a single yarn fineness of 5.5dtex, a polyester fineness of 150dtex, a breaking strength of 3.3cN / dtex, an elongation at break of 51%, a boiling water shrinkage of 15%, an oil content of 0.90%, and a hollowness of 8%.

[0081] Embodiment 2

[0082] The center angle of the first arc-shaped long hole of the spinneret is 205°, the diameter of the outer ring is 0.51mm, and the diameter of the inner ring is 0.40mm; the center angle of the second arc-shaped long hole is 190°, the diameter of the outer ring is 0.66mm, and the diameter of the inner ring is 0.53mm; the center angle of the third arc-shaped long hole is 130°, the diameter of the outer ring is 0.90mm, and the diameter of the inner ring is 0.62mm. The vertical spacing between the upper and lower fractures of the first arc-shaped long hole is 0.05mm; the vertical spacing between the upper and lower fractures of the second arc-shaped long hole is 0.08mm; the vertical spacing between the upper and lower fractures of the third arc-shaped long hole is 0.16mm. The shortest distance between the first arc-shaped long hole and the second arc-shaped long hole is 0.08mm; the shortest distance between the second arc-shaped long hole and the third arc-shaped long hole is 0.08mm.

[0083] The spinneret is used to prepare asymmetric double hollow curly polyester by adopting FDY process, through metering, extrusion, cooling, oiling, stretching, heat setting and winding of polyester melt.

[0084] The parameters of the FDY process are:

[0085] Spinning temperature: 290℃;

[0086] Cooling temperature: 25℃;

[0087] Network pressure: 0.30MPa;

[0088] One roller speed: 1700m / min;

[0089] First roller temperature: 85℃;

[0090] Second roller speed: 3800m / min;

[0091] Second roller temperature: 115℃;

[0092] Winding speed: 3740m / min.

[0093] The asymmetric double hollow curly polyester obtained by the above steps has a CV value of 5.0% and a U value of 4.5%, a single yarn fineness of 4.5dtex, a polyester fineness of 80dtex, a breaking strength of 3.4cN / dtex, an elongation at break of 48%, a boiling water shrinkage of 13%, an oil content of 1.10%, and a hollowness of 5%.

[0094] Embodiment 3

[0095] The center angle of the first arc-shaped long hole of the spinneret is 203°, the diameter of the outer ring is 0.51mm, and the diameter of the inner ring is 0.40mm; the center angle of the second arc-shaped long hole is 185°, the diameter of the outer ring is 0.66mm, and the diameter of the inner ring is 0.52mm; the center angle of the third arc-shaped long hole is 125°, the diameter of the outer ring is 0.89mm, and the diameter of the inner ring is 0.62mm. The vertical spacing between the upper and lower fractures of the first arc-shaped long hole is 0.05mm; the vertical spacing between the upper and lower fractures of the second arc-shaped long hole is 0.07mm; the vertical spacing between the upper and lower fractures of the third arc-shaped long hole is 0.15mm. The shortest distance between the first arc-shaped long hole and the second arc-shaped long hole is 0.07mm; the shortest distance between the second arc-shaped long hole and the third arc-shaped long hole is 0.09mm.

[0096] The spinneret is used to prepare asymmetric double hollow curly polyester by adopting FDY process, through metering, extrusion, cooling, oiling, stretching, heat setting and winding of polyester melt.

[0097] The parameters of the FDY process are:

[0098] Spinning temperature: 285℃;

[0099] Cooling temperature: 23℃;

[0100] Network pressure: 0.25MPa;

[0101] One roller speed: 1650m / min;

[0102] First roller temperature: 84℃;

[0103] Second roller speed: 3800m / min;

[0104] Second roller temperature: 115℃;

[0105] Winding speed: 3700m / min.

[0106] The asymmetric double hollow curly polyester obtained by the above steps has a CV value of 6.0% and a U value of 6.5%, a single yarn fineness of 7.0 dtex, a polyester fineness of 170 dtex, a breaking strength of 3.3 cN / dtex, a breaking elongation of 39%, a boiling water shrinkage of 10%, an oil content of 0.80%, and a hollowness of 7%.

[0107] Embodiment 4

[0108] The center angle of the first arc-shaped long hole of the spinneret is 205°, the diameter of the outer ring is 0.51mm, and the diameter of the inner ring is 0.39mm; the center angle of the second arc-shaped long hole is 185°, the diameter of the outer ring is 0.65mm, and the diameter of the inner ring is 0.52mm; the center angle of the third arc-shaped long hole is 120°, the diameter of the outer ring is 0.89mm, and the diameter of the inner ring is 0.62mm. The vertical spacing between the upper and lower fractures of the first arc-shaped long hole is 0.04mm; the vertical spacing between the upper and lower fractures of the second arc-shaped long hole is 0.08mm; the vertical spacing between the upper and lower fractures of the third arc-shaped long hole is 0.15mm. The shortest distance between the first arc-shaped long hole and the second arc-shaped long hole is 0.08mm; the shortest distance between the second arc-shaped long hole and the third arc-shaped long hole is 0.09mm.

[0109] The spinneret is used to prepare asymmetric double hollow curly polyester by adopting FDY process, through metering, extrusion, cooling, oiling, stretching, heat setting and winding of polyester melt.

[0110] The parameters of the FDY process are:

[0111] Spinning temperature: 288°C;

[0112] Cooling temperature: 25℃;

[0113] Network pressure: 0.30MPa;

[0114] One roller speed: 1700m / min;

[0115] First roller temperature: 85℃;

[0116] Second roller speed: 3800m / min;

[0117] Second roller temperature: 115℃;

[0118] Winding speed: 3730m / min.

[0119] The asymmetric double hollow curly polyester obtained by the above steps has a CV value of 5.8%, a U value of 6.0%, a single yarn fineness of 6.0 dtex, a polyester fineness of 160 dtex, a breaking strength of 3.5 cN / dtex, a breaking elongation of 41%, a boiling water shrinkage of 13%, an oil content of 0.80%, and a hollowness of 6%.

[0120] In summary, the spinneret holes of the spinneret are of a "9"-shaped structure. The spinneret is used to prepare asymmetric double hollow curly polyester with bamboo-shaped morphology by utilizing the hole expansion effect and the difference in shear rate. That is, a linen-like polyester that integrates the characteristics of special shape, hollowness, and curliness. It has a high unevenness of the strands. When heated, it will produce a curly morphology, which can produce capillary phenomena and increase the surface area of ​​the fiber. The prepared fabric has a fluffy feeling, improves the gloss effect and feel, and improves the air permeability of the fabric, greatly improving the application range of FDY. In addition, the asymmetric double hollow curly polyester has a hollow structure, which makes the fiber have a continuous cavity inside, reduces the mass of the fiber, and improves the lightweight degree of the fabric.

[0121] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0122] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A spinneret, characterized in that: Used to prepare asymmetric double hollow curled polyester, the spinneret includes a spinneret body and a plurality of spinneret holes formed on the spinneret body, the spinneret holes are of a "9"-like structure, the spinneret holes include a first arc-shaped long hole, a second arc-shaped long hole and a third arc-shaped long hole which are not connected to each other and are arranged in sequence, the first arc-shaped long hole, the second arc-shaped long hole and the third arc-shaped long hole are all of a "C"-like structure, and the first arc-shaped long hole and the second arc-shaped long hole have the same direction, and the second arc-shaped long hole and the third arc-shaped long hole have opposite directions; The central angle of the first arc-shaped long hole is 200°-205°, the diameter of the outer ring is 0.50-0.51mm, and the diameter of the inner ring is 0.39-0.40mm; the central angle of the second arc-shaped long hole is 180°-190°, the diameter of the outer ring is 0.65-0.66mm, and the diameter of the inner ring is 0.52-0.53mm; the central angle of the third arc-shaped long hole is 120°-130°, the diameter of the outer ring is 0.88-0.90mm, and the diameter of the inner ring is 0.60-0.62mm, wherein the outer ring and the inner ring are respectively the outer ring and the inner ring of the corresponding arc-shaped long hole; The vertical spacing between the upper break and the lower break of the first arc-shaped long hole is 0.04-0.05mm; the vertical spacing between the upper break and the lower break of the second arc-shaped long hole is 0.07-0.08mm; the vertical spacing between the upper break and the lower break of the third arc-shaped long hole is 0.15-0.16mm, wherein the upper break and the lower break are the intersection points of the straight line where the break is located and the outer ring and the inner ring respectively.

2. The spinneret according to claim 1, characterized in that The shortest distance between the first arc-shaped long hole and the second arc-shaped long hole is 0.07-0.08 mm; the shortest distance between the second arc-shaped long hole and the third arc-shaped long hole is 0.08-0.09 mm.

3. A method for preparing asymmetric double hollow crimped polyester, characterized in that: The asymmetric double hollow curly polyester is prepared by using the spinneret as described in any one of claims 1 to 2 and adopting the FDY process, through metering, extrusion, cooling, oiling, stretching, heat setting and winding of polyester melt.

4. The method for preparing the asymmetric double hollow crimped polyester according to claim 3, characterized in that: The parameters of the FDY process are: Spinning temperature: 280℃-290℃; Cooling temperature: 20℃-25℃; Network pressure: 0.20MPa-0.30MPa; One roller speed: 1500m / min-1700m / min; First roller temperature: 80℃-85℃; Second roller speed: 3700m / min-3800m / min; Second roller temperature: 105℃-115℃; Winding speed: 3650m / min-3740m / min.

5. An asymmetric double hollow curled polyester, characterized in that: The asymmetric double hollow curly polyester is prepared by the preparation method of any one of claims 3-4, wherein the cross-section of the asymmetric double hollow curly polyester is a "9"-shaped asymmetric double hollow structure, and the CV value of the asymmetric double hollow curly polyester is 4.5-6.0%, and the U value of the strip unevenness is 3.0-6.5%.

6. The asymmetric double hollow crimped polyester according to claim 5, characterized in that: The monofilament fineness of the asymmetric double hollow crimped polyester is 4.5-7.0 dtex.

7. The asymmetric double hollow crimped polyester according to claim 6, characterized in that: The asymmetric double hollow curled polyester has a fineness of 80-170 dtex, a breaking strength of ≥3.1 cN / dtex, a breaking elongation of 45.0±6.0%, a boiling water shrinkage of 10.0-15.0%, an oil content of 0.90±0.20%, and a hollowness of 5-10%.

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