1. A method for preparing quadrangle high-hollowness polyester staple fiber is characterized in that a fused spinning raw material melt is pressurized by a melt booster pump and cooled by a melt cooler, then uniformly distributed to a spinning manifold through a melt distribution pipeline, the melt enters the spinning manifold, quantitatively fed to a spinning assembly through a spinning metering pump, filtered, distributed and extruded to form a trickle through a spinneret orifice, the melt is cooled and solidified by quenching air through a ring blowing cooling device, a 150mm high movable baffle is arranged in a ring blowing liner to asymmetrically cool a nascent fiber, the ring blowing temperature is 16 ℃, the wind speed is 5-7 m/s, the wind pressure is 2500Pa, the humidity is 80-85%, the wind delivery enthalpy is 46Kj/kg, the nascent fiber is sequentially wound, dropped, bunched, and then subjected to oil bath, steam two-path drafting and curling, oiling, pre-cutting, and then subjected to relaxation heat setting, drying and shaping, finally preparing the quadrilateral high-hollowness polyester staple fiber;

the spinneret plate comprises a spinneret plate body (1) and a plurality of spinneret orifices (2) which are annularly distributed on the spinneret plate body (1); the spinneret orifice (2) consists of four sections of elongated arc-shaped orifices, namely a first elongated arc-shaped orifice (21), a second elongated arc-shaped orifice (22), a third elongated arc-shaped orifice (23) and a fourth elongated arc-shaped orifice (24); the first elongated arc-shaped hole (21), the second elongated arc-shaped hole (22), the third elongated arc-shaped hole (23) and the fourth elongated arc-shaped hole (24) are arranged into a structure similar to a diamond, and the concave surface of each section of elongated arc-shaped hole faces outwards;

wherein the polyester melt used has an intrinsic viscosity ofThe carboxyl end group is 27mol/t, the melting point is more than or equal to 260 ℃, the content of diethylene glycol is less than or equal to 1.2 wt/%, and the content of titanium dioxide is less than or equal to 0.32 wt/%;

the temperature of a gas phase heating medium of the spinning box body is 270-275 ℃; the spinning speed of the spinning manifold is 1000-1100 m/min, the specification of the metering pump is 100cc, and the rotating speed is 17-18 r/min.

2. The method for preparing the quadrilateral high-hollowness polyester staple fiber according to claim 1, wherein a static mixer is arranged in a melt distribution pipe to ensure uniform quality of melt entering a spinning manifold, a jacket pipe is adopted for heat preservation of the melt pipe, and a heat preservation medium is hydrogenated terphenyl; each set of melt conveying system is provided with two sets of secondary heat medium circulating systems, one set of secondary heat medium circulating systems is used for heat preservation of the melt conveying pipeline, and the other set of secondary heat medium circulating systems is used for a melt cooler as a cooling medium.

3. The method for producing quadrangular high-hollowness polyester staple fiber according to claim 1, wherein the finish used in the winding is a tow smoothing agent with a concentration of 0.5 to 0.8%.

4. The process for producing a quadrangular high-hollowness polyester staple fiber according to claim 1, wherein the drawing in an oil bath is carried out in a drawing tank between two drawing machines, the tow is heated in the drawing tank by the drawing bath at a drawing ratio of 3.3 to 3.5 at a drawing ratio of 85 to 90%, the temperature of the oil bath is 65 to 70 ℃, and the oil used is silicone oil at a concentration of 5 to 6%.

5. The method for preparing quadrilateral high-hollowness polyester staple fiber according to claim 1, wherein the steam drawing means that the filament bundle is drawn after being heated by a steam heating box, the drawing multiple is 1.08-1.1, and the temperature is 100-.

6. The method for preparing the quadrilateral high-hollowness polyester staple fibers according to claim 1, wherein the relaxation heat setting is carried out by a relaxation heat setting oven which is divided into 14 heating zones, the temperature is controlled to be 80-180 ℃, and the drying time is about 10-30 min.

Background

The characteristics of the three-dimensional hollow polyester fiber, which are closely related to the appearance of the cross section of the fiber and the contour of the three-dimensional hollow polyester fiber having a deformed cross section is irregular, can give a bulky feeling to the three-dimensional hollow polyester fiber fabric. The glossiness and the hand feeling of the fabric are improved, the quality of the textile is improved, and the air permeability and the pilling resistance are also improved. The three-dimensional hollow polyester fiber has a continuous hollow cavity inside, which reduces the volume quality of the fiber and improves the heat insulation and air permeability of the textile. The special-shaped three-dimensional hollow polyester fiber takes the integrally formed special-shaped structure into consideration and combines the three-dimensional hollow structure, and has a plurality of advantages compared with the traditional round three-dimensional hollow fiber. In the polyester fiber industry at present, most enterprises produce three-dimensional hollow polyester staple fibers based on the utilization of recycled polyester as a raw material source, the recycled polyester raw materials are further contracted along with the implementation of a solid waste ban, the advantages of the primary polyester are further expanded due to the release of capacity,

in the conventional production method of three-dimensional hollow fibers, C-shaped holes are mostly used for a spinneret plate which is commonly used. The cross section of the produced polyester fiber is difficult to keep a regular shape no matter in a single-lug or two-lug C-shaped hole, the conventional three-dimensional hollow polyester fiber mostly uses regenerated polyester, the temperature change of a screw extruder of used melt spinning equipment is unstable (the fluctuation range is 275-290 ℃) along with the increase of abrasion, the ring blowing temperature is above 20 ℃, the rapid cooling and forming of spinning ring blowing are not facilitated, and the expansion coefficient of a melt extruded from a spinneret plate is relatively high, so that the hollow rate of the fiber is low, and the hollowness of the fiber is unstable. The produced textile has poor plane glossiness.

Disclosure of Invention

The invention aims to provide a preparation method of quadrilateral high-hollowness polyester staple fibers, which can greatly improve the fiber reflection effect and improve the glossiness of chemical fibers. Compared with the traditional special-shaped three-dimensional hollow fiber, the hollow degree is higher, and the flexibility of the fiber is improved.

In order to solve the technical problem, the invention aims to realize that:

the invention relates to a method for preparing quadrangle high-hollowness polyester staple fiber, wherein the melt of the spinning raw material is pressurized by a melt booster pump and cooled by a melt cooler, then uniformly distributed to a spinning manifold through a melt distribution pipeline, the melt enters the spinning manifold, quantitatively fed to a spinning assembly through a spinning metering pump, filtered, distributed and extruded to form a trickle through a spinneret orifice, cooled and solidified by quenching air through a ring-blowing cooling device, a 150mm high movable baffle is arranged in a ring-blowing liner to asymmetrically cool the nascent fiber, the ring-blowing air temperature is 16 ℃, the air speed is 5 to 7m/s, the air pressure is 2500Pa, the humidity is 80-85 percent, the air-supply enthalpy is 46Kj/kg, then the nascent fiber is sequentially wound, dropped, bunched, and then subjected to oil bath, steam two-path drafting and curling, oiling, pre-cutting, and then subjected to loose heat setting, drying and shaping and packaging, finally preparing the quadrilateral high-hollowness polyester staple fiber;

the spinneret plate comprises a spinneret plate body and a plurality of spinneret orifices which are annularly distributed on the spinneret plate body; the spinneret orifice consists of four sections of elongated arc-shaped orifices, namely a first elongated arc-shaped orifice, a second elongated arc-shaped orifice, a third elongated arc-shaped orifice and a fourth elongated arc-shaped orifice; the first, second, third and fourth elongated arc-shaped holes are arranged into a structure similar to a diamond, and the concave surface of each section of the elongated arc-shaped hole faces outwards;

wherein the polyester melt used has an intrinsic viscosity ofThe carboxyl end group is 27mol/t, the melting point is more than or equal to 260 ℃, the content of diethylene glycol is less than or equal to 1.2 wt/%, and the content of titanium dioxide is less than or equal to 0.32 wt/%;

the temperature of a gas phase heating medium of the spinning box body is 270-275 ℃; the spinning speed of the spinning manifold is 1000-1100 m/min, the specification of the metering pump is 100cc, and the rotating speed is 17-18 r/min.

On the basis of the above scheme and as a preferable scheme of the scheme: a static mixer is arranged in the melt distribution pipe to ensure the uniform quality of the melt when entering the spinning manifold, the melt pipeline adopts a jacketed pipe for heat preservation, and the heat preservation medium is hydrogenated terphenyl; each set of melt conveying system is provided with two sets of secondary heat medium circulating systems, one set of secondary heat medium circulating systems is used for heat preservation of the melt conveying pipeline, and the other set of secondary heat medium circulating systems is used for a melt cooler as a cooling medium.

On the basis of the above scheme and as a preferable scheme of the scheme: the oil used in winding is a tow smoothing agent with a concentration of 0.5% to 0.8%.

On the basis of the above scheme and as a preferable scheme of the scheme: the oil bath drafting is carried out in an oil bath drafting groove between two drafting machines, the tows are heated by the drafting bath in the drafting groove, the drafting multiple is 3.3-3.5, the drafting ratio is 85-90%, the temperature of the oil bath groove is 65-70 ℃, and the used oil agent is silicone oil, and the concentration is 5-6%.

On the basis of the above scheme and as a preferable scheme of the scheme: the steam drafting refers to the drafting of the filament after the filament is heated by a steam heating box, the drafting multiple is 1.08-1.1, and the temperature is 100-.

On the basis of the above scheme and as a preferable scheme of the scheme: the relaxation heat setting is carried out by a relaxation heat setting oven which is divided into 14 heating zones, the temperature is controlled to be 80-180 ℃, and the drying time is about 10-30 min.

Compared with the prior art, the invention has the following beneficial effects:

1. by adopting the low-temperature spinning technology, the heat brought out by the short fiber melt can be reasonably reduced, the cooling and forming of micropores are facilitated, the extrusion expansion rate is ensured, the hollow rate is improved, and the special-shaped degree is ensured.

2, the low-temperature high-wind-speed circular blowing asymmetric cooling technology is adopted, so that the solidification and the forming of tows are facilitated, the extrusion expansion rate is ensured, the hollow rate is improved, and the degree of abnormal shape is ensured;

3. the low-draw ratio process design is adopted, the spinning speed is adjusted, the internal pressure of the assembly can be reduced, the extrusion expansion rate is ensured, the hollow rate is improved, and the abnormal shape degree is ensured;

4. the spinneret plate with the arc-shaped holes is adopted, the concave surfaces of the arc-shaped holes face outwards, the concave surfaces basically form a plane after the extrusion and expansion in the spinning process, and the fiber section can well keep the shape of a rhomboid quadrangle. The manufactured quadrilateral high hollow polyester staple fiber has very good plane glossiness. The defect of poor glossiness of the coarse denier round fibers is well overcome, and the glossiness and the application effect of the textile are improved.

Drawings

Fig. 1 is a schematic structural view of a spinneret plate according to an embodiment;

FIG. 2 is a schematic view of the structure of the spinneret orifice;

FIG. 3 is a schematic sectional view taken along line A-A of FIG. 2;

FIG. 4 is a schematic view of the spinneret hole according to the third embodiment.

The designations in the figures illustrate the following: 1-spinneret plate body; 2-spinneret orifices; 21-a first elongated arcuate aperture; 22-a second elongated arcuate aperture; 23-a third elongated arcuate aperture; 24-a fourth elongated arcuate aperture; 20-a spinneret core; 25-boss.

Detailed Description

The present invention is further illustrated by the following specific examples.

Example one

The present embodiment will be described in detail with reference to fig. 1 and 2. The embodiment relates to a method for preparing quadrangle high-hollowness polyester staple fiber, melt is pressurized by a melt booster pump and cooled by a melt cooler, then is uniformly distributed to a spinning manifold through a melt distribution pipeline, the melt enters the spinning manifold, is quantitatively delivered to a spinning assembly through a spinning metering pump, forms trickle through a spinneret orifice through filtering, distribution and extrusion, is cooled and solidified by quenching air through a ring blowing cooling device, is formed, a 150mm high movable baffle is arranged in a ring blowing inner container, performs asymmetric cooling on nascent fiber, has the ring blowing air temperature of 16 ℃, the air speed of 5-7 m/s, the air pressure of 2500Pa, the humidity of 80-85 percent and the air supply enthalpy value of 46Kj/kg, sequentially winds, falls filaments and bundles the nascent fiber, and then is subjected to oil bath, steam two-path drafting and curling, oiling, prepositive cutting, loose heat setting, drying and shaping, and packaging, finally, the quadrilateral high-hollowness polyester staple fiber is prepared. The process parameters in this example are as follows:

the spinneret plate used in the embodiment comprises a spinneret plate body 1 and a plurality of spinneret holes 2 which are annularly distributed on the spinneret plate body 1; the spinneret orifice 2 consists of four sections of elongated arc-shaped orifices, namely a first elongated arc-shaped orifice 21, a second elongated arc-shaped orifice 22, a third elongated arc-shaped orifice 23 and a fourth elongated arc-shaped orifice 24; the first, second, third and fourth elongated arc-shaped holes 21, 22, 23 and 24 are arranged in a diamond-like structure, and the concave surface of each section of the elongated arc-shaped hole faces outwards.

One end of the first elongated arc-shaped hole 21 is adjacent to and spaced from one end of the second elongated arc-shaped hole 22, and the other end is adjacent to and spaced from the fourth elongated arc-shaped hole 24; one end of the third elongated arc-shaped hole 23 is adjacent to and spaced from the other end of the second elongated arc-shaped hole 22, and the other end is adjacent to and spaced from the other end of the fourth elongated arc-shaped hole 24.

The spinneret plate with the arc-shaped holes is adopted, the concave surfaces of the arc-shaped holes face outwards, the concave surfaces basically form a plane after the extrusion and expansion in the spinning process, and the fiber section can well keep the shape of a rhomboid quadrangle. The manufactured quadrilateral high hollow polyester staple fiber has very good plane glossiness. The defect of poor glossiness of the coarse denier round fibers is well overcome, and the glossiness and the application effect of the textile are improved.

In the preparation process referred to in this example, the polyester melt used had an intrinsic viscosity of The carboxyl end group being27mol/t, the melting point is more than or equal to 260 ℃, the content of diethylene glycol is less than or equal to 1.2 wt/%, and the content of titanium dioxide is less than or equal to 0.32 wt/%;

the temperature of a gas phase heating medium of the spinning box body is 270-275 ℃; the spinning speed of the spinning manifold is 1000-1100 m/min, the specification of the metering pump is 100cc, and the rotating speed is 17-18 r/min.

A static mixer is arranged in the melt distribution pipe to ensure the uniform quality of the melt when entering the spinning manifold, the melt pipeline adopts a jacketed pipe for heat preservation, and the heat preservation medium is hydrogenated terphenyl; each set of melt conveying system is provided with two sets of secondary heat medium circulating systems, one set of secondary heat medium circulating systems is used for heat preservation of the melt conveying pipeline, and the other set of secondary heat medium circulating systems is used for a melt cooler as a cooling medium.

And winding the as-spun fiber drawn from the spinning assembly, wherein the oiling agent used in the winding is a tow smoothing agent with the concentration of 0.5-0.8%.

And (4) carrying out oil bath drafting and steam drafting on the wound tows. The oil bath drafting is carried out in an oil bath drafting groove between two drafting machines, the tows are heated by the drafting bath in the drafting groove, the drafting multiple is 3.3-3.5, the drafting ratio is 85-90%, the temperature of the oil bath groove is 65-70 ℃, and the used oil agent is silicone oil, and the concentration is 5-6%.

The steam drafting refers to the drafting of the filament after the filament is heated by a steam heating box, the drafting multiple is 1.08-1.1, and the temperature is 100-. Specifically, the draft ratio was 1.13 and the temperature was 108 ℃.

The relaxation heat setting is carried out by a relaxation heat setting oven which is divided into 14 heating zones, the temperature is controlled to be 80-180 ℃, and the drying time is about 10-30 min.

And (3) the fiber after twice drafting treatment is sprayed by an oiling agent spraying device to reduce the temperature of the filament, and then is drawn out by a third drafting roller. After the tows are cooled, three tows are stacked into a uniform silk slice which can meet the width of a stuffer box of a crimping machine through a silk stacking machine. Then the tension of the tows is adjusted through a three-roller tension adjusting machine, and then the tows enter a crimping machine for crimping. The filament bundle is controlled by a tension regulator to control the curling speed and ensure that the filament bundle has fixed tension before the crimper. The curling effect of the tows in the crimping machine can be adjusted by the pressure of a compression roller and a stuffing box, the curled tows are sent to a cutting platform by a cooling dryer, are sprayed by a spraying oiling device for additional oiling and then are drawn to a cutting room by a catching device through a yarn guide part, the tows are uniformly fed into a cutting machine under the control of a tension adjusting machine to be cut into short fibers with required length, then the tows are uniformly laid on a chain plate of a relaxation heat setting machine by a yarn swinging machine, and the tows in the relaxation heat setting machine are dried and set in a relaxation state. The drying room of the relaxation heat setting machine is of a building block combination type, and is divided into 14 heating zones, the temperature is controlled to be 80 ℃, 100 ℃, 110 ℃, 120 ℃, 140 ℃, 160 ℃, 180 ℃, 175 ℃, 180 ℃, 170 ℃, 160 ℃, 145 ℃ and 120 ℃ in sequence, and the two latter zones are cooling chambers and are filled with cold air for cooling so as to reduce the temperature of the tows. The drying time was about 30 min. And (5) carrying out conveying chain plate and packaging processing on the dried fiber.

By the process, various parameter indexes detected by the produced 7D 64mm quadrilateral high-hollowness polyester staple fiber product

The hollow rate: 36 percent

The degree of abnormity: 56 percent

Breaking strength: 3.8cn/dtex

Elongation at break: 15 percent of

Fineness CV%: 3 percent of

The length CV% is 3.8%

Double length fiber: 9.0mg/100 g.

Example two

This embodiment will be described in detail with reference to fig. 3. The difference between the preparation method of the quadrilateral high-hollowness polyester staple fiber in the embodiment and the embodiment one is that: the fourth elongated arcuate aperture 24 tapers in width from the melt inlet end a to the melt outlet end b. A boss 25 is provided at the melt outflow end b of the fourth elongated arc-shaped hole 24. Namely, the melt outflow end b of the fourth elongated arc-shaped hole 24 protrudes out of the lower surface of the spinneret plate body 1, so that the melt expands during the ejection and cannot form viscosity on the bottom surface of the plate body, and the spinning quality can be greatly improved.

The first, second, third and fourth elongated curved holes 21, 22, 23 and 24 have the same structure, and the structure of the fourth elongated curved hole 24 is described as an example.

The transition between the melt outflow end b of the fourth elongated arc-shaped hole 24 and the boss 25 may be a right angle or an arc.

EXAMPLE III

This embodiment will be described in detail with reference to fig. 4. The difference between the preparation method of the quadrangular high-hollowness polyester staple fiber related to the embodiment and the embodiment I or II is that: the spinneret orifice 2 is arranged on the spinneret core 20, and the spinneret core 20 is arranged in a through hole arranged on the spinneret plate body 1; the top surface of the spinneret core 30 is not higher than the surface of the spinneret body 1.

The spinning core 20 is provided with an external thread, and an internal thread is arranged in the through hole corresponding to the external thread, and the internal thread and the external thread are mutually screwed and connected to fix the spinning core 20 in the through hole.

The spinning core 20 is detachably arranged in the through hole on the spinneret plate body 1, and after the spinning core is damaged, only the damaged spinning core 20 needs to be detached and replaced, and the whole spinneret plate does not need to be replaced, so that the production cost of chemical fiber spinning operation is fundamentally reduced. And the spinneret plate body 1 and the spinneret core 20 are separately and independently processed, so that the manufacturing process of the spinneret plate becomes simple and easy, batch flow production of the spinneret plate is facilitated, and the production efficiency of manufacturing the spinneret plate is improved.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.