Sound insulation polyester FDY fiber and preparation method thereof

Abstract

The invention belongs to the technical field of sound insulation materials, and relates to a sound insulation polyester FDY fiber and a preparation method thereof. The preparation method comprises a spinning assembly spinning procedure, a circular air blowing cooling procedure, a stretching procedure, a shaping procedure and a main network procedure, in a spinning assembly, the number of spinneret orifices in a spinneret plate is 96-144, and the spinneret orifices are divided into two types; the two types of spinneret orifices are five-leaf-shaped; the number ratio of the first type of spinneret orifices to the second type of spinneret orifices is (1-2): 1; the diameter of the spinneret plate is 95 to 105 mm; stretching is jointly completed through a first hot roller, a second hot roller and a third hot roller, and the temperature of the first hot roller and the temperature of the second hot roller are 90-94 DEG C; shaping is completed through a third hot roller and a fourth hot roller; and the air pressure of the main network is 0.55-0.6 MPa. The sound insulation effect of the material is remarkably improved, and meanwhile the physical strength and the processing stability of the material are guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of sound insulation materials and relates to a sound insulation polyester FDY fiber and a preparation method thereof. Background Art

[0002] The rapid development of modern industry and technology, coupled with the intensification of production activities, has inevitably led to numerous environmental problems. Noise pollution, an invisible public hazard, is increasingly becoming a significant factor impacting people's quality of life, work efficiency, and physical and mental health. Whether it's the need for a quiet learning environment, a focused workplace, or the pursuit of high sound quality in leisure and entertainment spaces like recording studios, broadcast studios, cinemas, and concert halls, effective noise control measures are urgently needed.

[0003] Sound-absorbing and sound-insulating materials play a crucial role in traditional noise control. Currently, the mainstream sound-absorbing and noise-reducing materials on the market are mostly made of fine-denier, porous polyester fibers. These materials, through their unique microstructure—a large number of interconnected, tiny pores—effectively capture and dissipate incident noise waves. When sound waves strike the surface of the material, they stimulate the vibrations of air molecules within the fibers and their interstices. Friction, viscous resistance, and the material's thermal conductivity convert the sound energy into heat, significantly reducing the intensity of sound reflection and achieving the desired sound insulation and noise reduction effect.

[0004] However, while pursuing high-efficiency sound insulation, existing technologies also face some difficult-to-overcome challenges. For example, patent application CN108017360A proposes a porous sound insulation material. While adding inorganic additives such as gypsum and ceramsite to polyester fibers effectively increases the porosity between fibers, thereby enhancing sound insulation, this approach comes at the expense of the material's physical strength. Excessive additives reduce the fiber's overall mechanical properties, impacting the material's durability and range of applications.

[0005] The literature (Study on the Structure and Sound Absorption Performance of Composite Needle-Punched Nonwovens [J]. Nonwovens, 2009(4): 31-34) also points out that the fineness of the fiber has a direct impact on the sound absorption and sound insulation performance of the material. The finer the fiber, the higher the sound absorption and sound insulation coefficient of the material. However, excessive fiber refinement will lead to a significant decrease in fiber strength, which not only weakens the weaving processing performance of the material, but also shortens its service life, limiting the promotion of this type of high-performance material in practical applications.

[0006] To sum up, the current technical difficulties that need to be solved urgently in the field of sound-absorbing and sound-insulating materials are how to further improve their sound insulation effect without sacrificing the physical strength and processing performance of the materials, and develop new sound-absorbing and sound-insulating materials that are both efficient and durable to meet the growing demand for noise control. Summary of the Invention

[0007] The purpose of the present invention is to solve the problems existing in the prior art and provide a sound-insulating polyester FDY fiber and a preparation method thereof.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] A method for preparing sound-insulating polyester FDY fiber includes a spinning assembly spinning process, a ring-blowing cooling process, a stretching process, a shaping process, and a main network process. In the spinning assembly, the number of spinnerets on the spinneret is 96-144, which are divided into two categories.

[0010] Both types of spinnerets are pentaflobes, which consist of a circle and five long lobes connected to the circle and distributed radially. The diameter of the circle is 0.23±0.01mm, and the angle between two adjacent lobes is 72°.

[0011] The leaf length of the first type of spinneret is 0.4 mm and the leaf width is 0.055 mm; the leaf length of the second type of spinneret is 0.4 mm and the leaf width is 0.03 mm;

[0012] The ratio of the number of the first type of spinnerets to the number of the second type of spinnerets is 1-2:1;

[0013] The diameter of the spinneret is 95-105 mm;

[0014] Stretching is completed by the first hot roller, the second hot roller and the third hot roller. The temperature of the first hot roller and the second hot roller is 90-94℃.

[0015] The shaping is completed by the third and fourth hot rollers;

[0016] The air pressure of the main network is 0.55-0.6MPa.

[0017] The present invention designs the sizes of the two types of spinnerets so that the filaments extruded from the first type of spinnerets have a relatively large single filament fineness and a relatively small relative radial profile, which are denoted as single filament A; the filaments extruded from the second type of spinnerets have a relatively small single filament fineness and a relatively large relative radial profile, which are denoted as single filament B.

[0018] Controlling the temperatures of the first and second heated rollers and the air pressure of the main network can cause fuzz to be distributed on the surface of the sound-insulating polyester FDY fiber (a multifilament composed of multiple monofilaments A and multiple monofilaments B) for the following reasons:

[0019] When monofilaments A and B pass through the first and second heated rollers, due to the high temperatures of the first and second heated rollers, they are prone to crystallization and setting. Subsequently, during stretching and setting, monofilament B, which has a relatively small monofilament fineness and a relatively large relative radial profile, is prone to fuzz, while monofilament A, which has a relatively large monofilament fineness and a relatively small relative radial profile, is less likely to have fuzz.

[0020] During the main network, the monofilament B with relatively small monofilament fineness and relatively large relative radial profile is more likely to break than the monofilament A with relatively large monofilament fineness and relatively small relative radial profile. By controlling the air pressure of the main network, the monofilament B can be broken and entangled with the monofilament A at the same time, forming dense and uniform hairs on the surface of the sound-insulating polyester FDY fiber, and the monofilament A will not break, thereby ensuring the strength of the sound-insulating polyester FDY fiber.

[0021] When the spinneret diameter is large (95-105 mm), the heat dissipation speed of the plate surface is fast and the plate surface temperature is relatively low, which is equivalent to a fast cooling speed and a higher relative radial profile. When passing through the main network, the single filament B is more likely to produce hair.

[0022] Controlling the number ratio of the first type of spinneret holes to the second type of spinneret holes can ensure that the sound insulation polyester FDY fiber has high strength and stable post-processing performance.

[0023] The fabric containing the sound-insulating polyester FDY fiber has good sound insulation performance. The main reasons are as follows:

[0024] ① The cross section of the monofilament in the sound-insulating polyester FDY fiber is pentafolic, which has many edges and corners. When the sound propagates into the fabric, it will cause the fibers and the air between the fibers to vibrate. Due to this vibration, more friction will be generated between the air and the fibers, and this friction will reduce the sound.

[0025] ② The cross-section of the single fiber in the sound-insulating polyester FDY fiber is pentafolic, with relatively more pentafolic leaves. When the sound propagates to the surface of the fiber, it will produce more diffuse reflections (after one incidence and multiple reflections). Since different reflected sound waves are prone to misalignment, they can weaken or even cancel out the sound. At the same time, multiple reflections are equivalent to increasing the sound propagation path, thereby weakening the sound.

[0026] ③ The number of monofilaments in the sound-insulating polyester FDY fiber is large (96-144), and the cross-section of the monofilament is pentaflobate and small in size, which makes the specific surface area of the sound-insulating polyester FDY fiber larger. When sound propagates, the sound waves interact with the fibers more strongly, thereby achieving a stronger effect in reducing sound.

[0027] ④ The surface of sound-insulating polyester FDY fiber is covered with hairs. These hairs are curved and feathery, which easily resonate with sound waves, absorb energy, and reduce the intensity of sound waves. At the same time, it makes the fabric fluffier, which is equivalent to increasing the density and thickness of the fabric, and also increases the sound propagation path, thereby improving the sound insulation and sound absorption effects.

[0028] As the preferred technical solution:

[0029] As described above, in the preparation method of a sound-insulating polyester FDY fiber, all the spinnerets are distributed in concentric circles on the spinneret, the first type of spinnerets are arranged in the outer circle of the spinneret, and the second type of spinnerets are arranged in the inner circle of the spinneret. With such a design, under the same cooling air pressure conditions, the monofilament B can be cooled evenly, while the monofilament A will have a slight insufficient cooling, resulting in higher elongation at break and boiling water shrinkage.

[0030] In the above-mentioned method for preparing a sound-insulating polyester FDY fiber, in the spinning assembly, the filter sand adopts 150-180 g (total mass of the metal sand) and 50-70 mesh metal sand.

[0031] The mesh size of the metal sand selected in the present invention is appropriate, which can not only ensure the filtering accuracy, but also avoid the instantaneous increase of the melt temperature caused by the high pressure of the spinning assembly, which affects the relative radial profile of the fiber.

[0032] In the above-mentioned method for preparing the sound-insulating polyester FDY fiber, the spinning temperature is 286-290°C.

[0033] The spinning temperature of the present invention is relatively low, which can increase the relative radial profile of the fiber on the one hand, and on the other hand increase the expansion effect of the polyester melt at the spinneret hole, so that the monofilament B has a smaller residual elongation and a relatively low breaking strength after stretching during the spinning process, so that it is easier to produce uniform hairy fibers when subjected to high-pressure impact from the main network.

[0034] In the preparation method of the sound-insulating polyester FDY fiber described above, the cooling air pressure of the annular air cooling is 35-40 Pa, the length of the cooling air cylinder is 48-50 cm, and the height of the slow cooling zone is 55-60 mm.

[0035] The specific cooling air pressure, cooling air duct length, and slow cooling zone height allow the monofilament B to be cooled properly, while the monofilament A is not cooled properly, resulting in large elongation at break and boiling water shrinkage. After later weaving, the monofilament A with high boiling water shrinkage presents small loops floating on the surface of the fabric, which has a fluffy effect and can make the end face of the fabric feel denser, thereby improving the sound insulation performance.

[0036] In the above-mentioned method for preparing sound-insulating polyester FDY fiber, the speed ratio of the third heated roller to the first heated roller (ie, the stretching ratio) is 2.0-2.5.

[0037] During the stretching process, the monofilament B is prone to produce low-strength and low-elongation monofilaments due to the large stretching ratio, and is more likely to produce hairy fibers after high-pressure blowing through the main network.

[0038] The preparation method of the sound-insulating polyester FDY fiber as described above has the following overall process flow: the melt is extruded through a metering pump → spinning by a spinning assembly → cooling by annular air → first oiling → first pre-networking → first guide roller → first hot roller → second hot roller → third hot roller → fourth hot roller → second guide roller → second oiling → second pre-networking → main network → third guide roller → winding and forming.

[0039] In the preparation method of the sound-insulating polyester FDY fiber as described above, the first pre-network is located 130-140 cm below the spinneret, the air pressure of the first pre-network is 0.03-0.04 MPa, and the air pressure of the second pre-network is 0.1-0.15 MPa.

[0040] Pre-interlacing the tow improves fiber bundling and cohesion. After the primary interlacing process, the fibers are able to cohere in large quantities and do not fall off in the tow. Because the tow speed is high and the tension is relatively high during the second pre-interlacing process, the air pressure during the second pre-interlacing process is slightly higher.

[0041] The present invention also provides a sound-insulating polyester FDY fiber prepared by the preparation method of a sound-insulating polyester FDY fiber as described in any of the above items, wherein filaments are distributed on the surface, the length of the filaments is 0.5-1.0 cm, the filaments are curved, and the bending radius is 2-4 cm; the breaking strength of the sound-insulating polyester FDY fiber is ≥3.84 cN / dtex, the elongation at break is 28.8-32.7%, the abnormal shrinkage rate is 12.4-18.2%, the relative radial anomaly is ≥24.7% (a high relative radial anomaly means that the five-leaf leaf is longer and the sound absorption effect is better), the oil content is 0.39-0.45%, and the filament rate is ≥91.5%.

[0042] The present invention also provides a method for preparing a sound-insulating polyester composite fiber, comprising: passing a polyester POY fiber and a sound-insulating polyester FDY fiber in parallel through a pre-net, a first roller, a first heat box, and a cooling plate in sequence; then passing the polyester POY fiber through a false twister and then plying the fiber with the sound-insulating polyester FDY fiber at a second roller; and then passing through a net, an auxiliary roller, a second heat box, a third roller, oiling, and winding to obtain the sound-insulating polyester composite fiber.

[0043] The sound-insulating polyester FDY fiber is the sound-insulating polyester FDY fiber described above;

[0044] The temperature of the first hot box is 150-160°C.

[0045] Due to the five-lobed, irregular cross-section of sound-insulating polyester FDY fibers, their breaking strength is relatively low, and hairiness is distributed on the surface of the filaments. This easily accumulates hairiness during the subsequent weaving process. If excessive hairiness accumulates during combing, it is prone to breakage. Furthermore, if the sound-insulating polyester FDY fibers are directly woven, without further plasticization in a high-temperature hot box, the hairiness will not be properly curved, resulting in relatively poor sound insulation. Therefore, the present invention combines sound-insulating polyester FDY fibers with polyester POY fibers to produce a sound-insulating polyester composite fiber, which is then used as the fiber raw material for woven fabrics.

[0046] There are two main processes for producing composite fibers in the existing technology:

[0047] ① The FDY fiber is interwoven with the POY fiber which has passed through the pre-interwoven, first roller, first hot box, cooling plate, false twister and second roller in sequence, and then passed through the auxiliary roller, second hot box, third roller, oiling and winding to obtain the differential shrinkage fiber;

[0048] ② The POY fiber and the FDY fiber are pre-networked together, and then sequentially passed through the first roller, the first hot box, the cooling plate, the false twister, the second roller, the second hot box, the third roller, oiled, and wound to obtain the cotton-like fiber.

[0049] The process for producing composite fibers of the present invention is different from that of the prior art. On the one hand, the FDY fibers of the present invention have passed through a first hot box before being composited with the POY fibers. This is to improve the fluffiness of the FDY fibers and make them feel fuller. The temperature of the first hot box needs to be appropriate. If the temperature of the first hot box is too high, the filaments of the sound-insulating polyester FDY fibers are easily broken. If the temperature of the first hot box is too low, the polyester POY fibers are not fully softened, and the filaments are easily broken when passing through a false twister. On the other hand, the FDY fibers of the present invention do not pass through a false twister. This is because the FDY fibers of the present invention have more filaments and are easily broken if passed through a false twister.

[0050] As the preferred technical solution:

[0051] In the preparation method of the sound-insulating polyester composite fiber as described above, the speed of the second roller is 600-620 m / min. The speed of the second roller is relatively low, mainly to ensure production stability and the velvety feel of the product, so that the two bundles of yarn have good cohesion.

[0052] As described above, in the preparation method of a sound-insulating polyester composite fiber, the speed ratio of the second roller to the first roller is 1.65-1.68, and the ratio of the surface linear speed of the friction disk of the false twister to the speed of the second roller is 1.60-1.65, which is mainly used for false twist deformation of polyester POY fiber.

[0053] In the above-mentioned method for preparing a sound-insulating polyester composite fiber, the temperature of the second heat box is 175-185° C., and its main function is to set the shape.

[0054] The present invention also provides a sound-insulating polyester composite fiber prepared by the preparation method of a sound-insulating polyester composite fiber as described in any of the above items, wherein the breaking strength of the sound-insulating polyester composite fiber is ≥3.25cN / dtex, the elongation at break is 14.1-15.9%, the oil content is 2.8-3.2%, the curl shrinkage is 14.3-15.7% (ensuring the curl and fluffiness of the fiber), the curl stability is ≥78.6%, and the hair rate is ≥91.6%; the sound absorption coefficient a of the fabric made from the sound-insulating polyester composite fiber is ≥0.22.

[0055] Beneficial effects:

[0056] (1) The present invention designs two types of spinnerets with different sizes and profiles to produce sound-insulating polyester FDY fibers consisting of a monofilament A with a larger monofilament fineness and a smaller profile, and a monofilament B with a smaller monofilament fineness and a larger profile. This design enables dense and uniform hairs to form on the fiber surface, increases the specific surface area of the fiber, enhances the interaction with sound waves, and thus significantly improves the sound insulation performance.

[0057] (2) The present invention precisely controls parameters such as the air pressure of the first hot roller, the second hot roller, and the main network, so that the monofilament B is easy to break during the stretching process and entangled with the monofilament A, forming an ideal hairy effect, while ensuring the integrity of the monofilament A, thereby achieving an improvement in sound insulation performance without sacrificing fiber strength.

[0058] (3) The sound-insulating polyester FDY fiber is compounded with the polyester POY fiber to obtain the sound-insulating polyester composite fiber. This step not only further enhances the sound-insulating performance of the fiber, but also improves the fluffiness of the sound-insulating polyester FDY fiber and makes the velvet feel fuller through the preparation process of the composite fiber. At the same time, the sound-insulating polyester FDY fiber and its composite fiber are not easy to break in the subsequent weaving process and are easy to be processed into sound-insulating materials of various shapes and sizes, meeting the noise control needs of different occasions. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 Schematic diagram of the distribution of spinneret holes on the spinneret used in Example 1;

[0060] Figure 2 for Figure 1 Schematic diagram of the shapes of the two types of spinneret holes;

[0061] Figure 3 Schematic diagram of the shapes of two types of spinnerets in Comparative Example 3;

[0062] Figure 4Schematic diagram of the distribution of spinneret holes on the spinneret used in Example 5;

[0063] Among them, A is the first type of spinneret, B is the second type of spinneret, d1 represents the leaf length, d2 represents the leaf width, and d3 represents the diameter of the circle that makes up the five-leaf shape. DETAILED DESCRIPTION

[0064] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0065] The following are the test methods for the relevant performance indicators in each embodiment and comparative example:

[0066] Whether there is hairy silk: Through visual observation, if there are single broken silk threads on the surface of each silk roll, it is hairy silk.

[0067] The length of the hair: observe the appearance and measure with a ruler.

[0068] The radius of the hair wire bending: observe the appearance and measure with a ruler.

[0069] Breaking strength and elongation at break: According to the "Test Method for Tensile Properties of Chemical Fiber Filament Materials" (GB / T 14344-2022), the elongation at break of the yarn tow was tested using a YG023B-Ⅱ fully automatic single yarn strength tester. The specific process is as follows: First, the yarn tow was placed in an environment with a temperature of (20±2)°C and a humidity of (65±5)% for 4 hours. Subsequently, the fully automatic single yarn strength tester was used for tensile testing. Before the test, the clamping length of the yarn tow was precisely set to (500±1.0) mm using the upper and lower clamps, and a pretension of (0.05±0.005 cN / dtex) was applied by the manipulator to stabilize the yarn tow. During the test, the lower clamp stretched the yarn tow at a set speed (500 mm / min) until the tow broke. During the stretching process, the force sensor recorded the data in real time, and the relationship between strength and elongation was plotted using the data collection system. Finally, the breaking strength and elongation of the yarn tow were obtained through data processing and analysis.

[0070] Shrinkage rate: Tested in accordance with the standard "Test method for shrinkage rate of polyester pre-oriented yarn, drawn yarn and blended yarn" (FZ / T 50023-2014).

[0071] Relative radial profile: According to the Test Method for Chemical Fiber Profile (FZ / T 50002-2013), the cross section of the fiber is magnified by a microscope, and the radius of the inscribed circle and the radius of the circumscribed circle in the fiber cross section are calculated. The relative radial profile D is calculated according to the following formula R :

[0072] D R =(1-r / R)×100%;

[0073] Where r is the radius of the inscribed circle in the fiber cross section (mm), and R is the radius of the circumscribed circle in the fiber cross section (mm).

[0074] Oil content: According to the "Test Method for Oil Content of Chemical Fibers" (GB / T 6504-2017), weigh about 2g of sample and use MQC23-10 nuclear magnetic resonance oil content analyzer for testing.

[0075] Hair rate: Hair rate = total number of hairs × 100% / total number of hairs.

[0076] Crimp shrinkage and crimp stability: Tested using the YG368 fully automatic filament crimp tester in accordance with the "Test method for crimp performance of synthetic textured yarns" (GB / T 6506-2017).

[0077] Sound absorption coefficient a: The sample to be tested is first woven into a fabric using a circular machine, and then tested according to GB / T 18696.1 "Measurement of sound absorption coefficient and acoustic impedance in acoustic impedance tubes Part 1: Standing wave ratio method".

[0078] Example 1

[0079] A method for preparing sound-insulating polyester FDY fiber, the overall process flow is: melt extrusion through a metering pump → spinning by a spinning assembly → cooling with annular air → first oiling → first pre-internetting → first godet roller → first heated roller → second heated roller → third heated roller → fourth heated roller → second godet roller → second oiling → second pre-internetting → main internetting → third godet roller → winding and forming;

[0080] The melt preparation process is as follows: slurry preparation → first esterification → second esterification → pre-polycondensation → final polycondensation → polyester melt (intrinsic viscosity 0.620 dL / g); related process parameters are: slurry liquid level 69%, the mass of PTA in the slurry accounts for 69% of the total mass of PTA and EG; first esterification temperature 268°C, first esterification pressure 90 kPa, second esterification temperature 270°C, second esterification pressure 30 kPa, pre-polycondensation upper chamber temperature 278°C, pre-polycondensation upper chamber pressure 35 kPa, pre-polycondensation lower chamber temperature 280°C, pre-polycondensation lower chamber pressure 1.8 kPa, final polycondensation inlet temperature 280°C, final polycondensation outlet temperature 286°C, final polycondensation vacuum 160 Pa;

[0081] In the spinning assembly, the diameter of the spinneret is 105 mm; the spinneret holes on the spinneret are divided into two categories, both of which are five-lobed, such as Figure 2 As shown in the figure, the pentafoil is composed of a circle and five long lobes connected to the circle and distributed radially. The diameter of the circle is 0.23 mm, and the angle between two adjacent lobes in the pentafoil is 72°. The lobe length of the first type of spinneret is 0.4 mm and the lobe width is 0.055 mm. The lobe length of the second type of spinneret is 0.4 mm and the lobe width is 0.03 mm. Figure 1 As shown, the centers of all the spinnerets are distributed in concentric circles on the spinneret, with a total of 6 circles. The spinnerets on each circle are evenly distributed. The circle that first appears from the inside to the outside is marked as the first circle. The diameter of the first circle is 20 mm, and 8 second-class spinnerets are distributed on the first circle. The diameter of the second circle is 33 mm, and 14 second-class spinnerets are distributed on the second circle. The diameter of the third circle is 46 mm, and 22 second-class spinnerets are distributed on the third circle. The diameter of the fourth circle is 59 mm, and 28 second-class spinnerets are distributed on the fourth circle. The diameter of the fifth circle is 72 mm, and 36 first-class spinnerets are distributed on the fifth circle. The diameter of the sixth circle is 86 mm, and 36 first-class spinnerets are distributed on the sixth circle.

[0082] In the spinning assembly, the filter sand is 180g, 50-70 mesh metal sand; the spinning temperature is 286℃;

[0083] The cooling air pressure of the ring air cooling is 40Pa, the cooling air cylinder length is 50cm, and the slow cooling zone height is 60mm;

[0084] The position of the first pre-network is 130 cm below the spinneret, and the air pressure of the first pre-network is 0.04 MPa;

[0085] The temperature of the first hot roller is 90°C;

[0086] The temperature of the second hot roller is 90°C;

[0087] The speed ratio of the third hot roller to the first hot roller is 2.1;

[0088] The air pressure of the second pre-network is 0.15MPa;

[0089] The air pressure of the main network is 0.55MPa.

[0090] The final sound-insulating polyester FDY fiber has hair distributed on its surface, the length of the hair is 0.5 cm, the hair is curved and the bending radius is 2 cm; the breaking strength of the sound-insulating polyester FDY fiber is 3.87 cN / dtex, the elongation at break is 31.6%, the shrinkage rate is 18.2%, the relative radial profile is 30.4%, the oil content is 0.45%, and the hair rate is 96.7%.

[0091] A method for preparing a sound-insulating polyester composite fiber, comprising: passing a polyester POY fiber (specification: 82 dtex / 48 f, with physical indicators: breaking strength: 2.64 cN / dtex, elongation at break: 131.8%, strand unevenness CV value: 1.03%, and oil content: 0.34%) and the sound-insulating polyester FDY fiber prepared in this embodiment in parallel through a pre-net, a first roller, a first hot box, and a cooling plate; then passing the polyester POY fiber through a false twister and then plying the fiber with the sound-insulating polyester FDY fiber on a second roller; and then passing through a net, an auxiliary roller, a second hot box, a third roller, oiling, and winding to obtain the sound-insulating polyester composite fiber;

[0092] Among them, the polyester POY fiber and the sound insulation polyester FDY fiber are both 1 bundle; the temperature of the first hot box is 160°C; the speed of the second roller is 600m / min, the speed ratio of the second roller to the first roller is 1.65, the ratio of the surface linear speed of the friction disk of the false twister to the speed of the second roller is 1.6; the temperature of the second hot box is 185°C.

[0093] The final sound-insulating polyester composite fiber has a breaking strength of 3.25 cN / dtex, an elongation at break of 14.7%, an oil content of 3.2%, a curl shrinkage of 15.7%, a curl stability of 80.8%, and a hair rate of 96.8%; the sound absorption coefficient a of the fabric made of the sound-insulating polyester composite fiber is 0.54.

[0094] Comparative Example 1

[0095] A method for preparing polyester FDY fiber differs from Example 1 only in that: the centers of all spinnerets are distributed in concentric circles on the spinneret, with a total of 6 circles. The spinnerets on each circle are evenly distributed, and the circle that appears first from the inside to the outside is marked as the first circle. The diameter of the first circle is 20 mm, and 4 second-class spinnerets are distributed on the first circle. The diameter of the second circle is 33 mm, and 7 second-class spinnerets are distributed on the second circle. The diameter of the third circle is 46 mm, and 11 second-class spinnerets are distributed on the third circle. The diameter of the fourth circle is 59 mm, and 14 second-class spinnerets are distributed on the fourth circle. The diameter of the fifth circle is 72 mm, and 18 first-class spinnerets are distributed on the fifth circle. The diameter of the sixth circle is 86 mm, and 18 first-class spinnerets are distributed on the sixth circle.

[0096] A method for preparing a polyester composite fiber is different from Example 1 only in that the sound-insulating polyester FDY fiber prepared in Example 1 is replaced by the polyester FDY fiber prepared in this comparative example.

[0097] The sound absorption coefficient a of the fabric finally made of the polyester composite fiber is 0.18.

[0098] Compared with Example 1, the sound absorption coefficient a of the fabric made of polyester composite fibers in Comparative Example 1 is significantly reduced. This is because in Comparative Example 1, the number of spinnerets on the spinneret is too low, which means that the number of monofilaments of the polyester FDY fiber is too small, and thus its specific surface area is relatively small. When sound propagates, the interaction between the sound waves and the fibers is not strong enough to effectively reduce the sound, which is manifested as a significant reduction in the sound absorption coefficient a of the fabric.

[0099] Comparative Example 2

[0100] A method for preparing polyester FDY fiber is different from Example 1 only in that: both types of spinnerets are four-lobed, and the angle between two adjacent lobes is 90°.

[0101] A method for preparing a polyester composite fiber is different from Example 1 only in that the sound-insulating polyester FDY fiber prepared in Example 1 is replaced by the polyester FDY fiber prepared in this comparative example.

[0102] The sound absorption coefficient a of the fabric finally made of the polyester composite fiber is 0.14.

[0103] Compared with Example 1, the sound absorption coefficient a of the fabric made of polyester composite fibers in Comparative Example 2 is significantly reduced. This is because the two types of spinnerets used in Comparative Example 2 are both four-lobed, and the four-lobed shape has fewer edges and corners. When the sound propagates into the interior of the fabric, the degree of vibration of the fibers and the air between the fibers is relatively weak, and the sound cannot be effectively reduced, which is manifested as a significant reduction in the sound absorption coefficient a of the fabric.

[0104] Comparative Example 3

[0105] A method for preparing polyester FDY fiber, which differs from Example 1 only in that the angles formed by the five lobes of the two types of five-lobed spinnerets are the same as Figure 3 shown.

[0106] Compared with Example 1, the relative radial profile of the polyester FDY fiber in Comparative Example 3 is significantly reduced. This is because the angles formed by the five lobes of the two types of five-lobed spinnerets in Comparative Example 3 are different. The lobes with smaller angles are affected by the expansion of the melt after extrusion from the spinneret, resulting in a lower relative radial profile.

[0107] A method for preparing a polyester composite fiber is different from Example 1 only in that the sound-insulating polyester FDY fiber prepared in Example 1 is replaced by the polyester FDY fiber prepared in this comparative example.

[0108] The sound absorption coefficient a of the fabric finally made of the polyester composite fiber is 0.19.

[0109] Compared with Example 1, the sound absorption coefficient a of the fabric made of polyester composite fibers in Comparative Example 3 is significantly reduced. This is because the angles formed by the five lobes of the two types of five-lobed spinnerets used in Comparative Example 3 are different. The lobes with smaller angles are affected by the expansion of the melt after extrusion from the spinneret, resulting in a lower relative radial profile of the polyester FDY fiber, that is, the cross-section of the fiber tends to be more circular, and the angularity of the fiber surface is correspondingly reduced, which affects the sound absorption effect.

[0110] Comparative Example 4

[0111] A method for preparing polyester FDY fiber differs from Example 1 only in that: the centers of all spinnerets are distributed in concentric circles on the spinneret, with a total of 6 circles. The spinnerets on each circle are evenly distributed, and the circle that appears first from the inside to the outside is marked as the first circle. The diameter of the first circle is 20 mm, and 8 second-class spinnerets are distributed on the first circle. The diameter of the second circle is 33 mm, and 14 second-class spinnerets are distributed on the second circle. The diameter of the third circle is 46 mm, and 22 second-class spinnerets are distributed on the third circle. The diameter of the fourth circle is 59 mm, and 28 second-class spinnerets are distributed on the fourth circle. The diameter of the fifth circle is 72 mm, and 36 second-class spinnerets are distributed on the fifth circle. The diameter of the sixth circle is 86 mm, and 36 first-class spinnerets are distributed on the sixth circle.

[0112] A method for preparing a polyester composite fiber is different from Example 1 only in that the sound-insulating polyester FDY fiber prepared in Example 1 is replaced by the polyester FDY fiber prepared in this comparative example.

[0113] The sound absorption coefficient a of the fabric finally made of the polyester composite fiber is 0.19.

[0114] Compared with Example 1, the sound absorption coefficient a of the fabric made of polyester composite fibers in Comparative Example 4 is significantly reduced. This is because in Comparative Example 4, the number of second-type spinnerets is too high, that is, the proportion of monofilament B is too large, the monofilament B has a relatively small fineness, a relatively large relative radial profile, and a weak strength, which affects the strength of the polyester FDY fiber. As a result, when it is subsequently composited with the polyester POY fiber, the monofilament is prone to breakage, which leads to poor structural stability of the composite fiber and affects the sound absorption effect.

[0115] Comparative Example 5

[0116] A method for preparing polyester FDY fiber, which differs from Example 1 only in that the temperatures of the first hot roller and the second hot roller are both 85°C.

[0117] A method for preparing a polyester composite fiber is different from Example 1 only in that the sound-insulating polyester FDY fiber prepared in Example 1 is replaced by the polyester FDY fiber prepared in this comparative example.

[0118] The sound absorption coefficient a of the fabric finally made of the polyester composite fiber is 0.17.

[0119] Compared with Example 1, the sound absorption coefficient a of the fabric made of polyester composite fiber in Comparative Example 5 is significantly reduced. This is because the temperatures of the first hot roller and the second hot roller in Comparative Example 5 are too low, resulting in insufficient crystallization and shaping of monofilaments A and B, affecting the stability of the internal structure of the fiber. Monofilament B is not prone to fuzz, which affects the sound absorption effect.

[0120] Comparative Example 6

[0121] A method for preparing polyester FDY fiber, which differs from Example 1 only in that the air pressure of the main network is 0.5 MPa.

[0122] A method for preparing a polyester composite fiber is different from Example 1 only in that the sound-insulating polyester FDY fiber prepared in Example 1 is replaced by the polyester FDY fiber prepared in this comparative example.

[0123] The sound absorption coefficient a of the fabric finally made of the polyester composite fiber is 0.19.

[0124] Compared with Example 1, the sound absorption coefficient a of the fabric made of polyester composite fibers in Comparative Example 6 is significantly reduced. This is because the air pressure of the main network in Comparative Example 6 is too low, making it difficult for the monofilament B with relatively small monofilament fineness and relatively large relative radial profile to be fully broken and entangled with the monofilament A, and unable to form dense and uniform hairs on the surface of the polyester FDY fiber, resulting in resonance with the sound waves, weakened energy absorption effect, and reduced sound absorption coefficient a of the fabric.

[0125] Example 2

[0126] A method for preparing sound-insulating polyester FDY fiber, the overall process flow is: melt extrusion through a metering pump → spinning by a spinning assembly → cooling with annular air → first oiling → first pre-internetting → first godet roller → first heated roller → second heated roller → third heated roller → fourth heated roller → second godet roller → second oiling → second pre-internetting → main internetting → third godet roller → winding and forming;

[0127] The melt preparation process is as follows: slurry preparation → first esterification → second esterification → pre-polycondensation → final polycondensation → polyester melt (intrinsic viscosity 0.630 dL / g); relevant process parameters are: slurry liquid level 70%, the mass of PTA in the slurry accounts for 69.5% of the total mass of PTA and EG; first esterification temperature 270°C, first esterification pressure 105 kPa, second esterification temperature 278°C, second esterification pressure 40 kPa, pre-polycondensation upper chamber temperature 282°C, pre-polycondensation upper chamber pressure 38 kPa, pre-polycondensation lower chamber temperature 285°C, pre-polycondensation lower chamber pressure 1.9 kPa, final polycondensation inlet temperature 282°C, final polycondensation outlet temperature 288°C, and final polycondensation vacuum 250 Pa;

[0128] In the spinning assembly, the diameter of the spinneret is 95mm; the spinnerets on the spinneret are divided into two categories, both of which are pentaflobes. The pentaflobes consist of a circle and five long lobes connected to the circle and distributed radially. The diameter of the circle is 0.22mm, and the angle between two adjacent lobes in the pentaflobes is 72°. The leaf length of the first type of spinneret is 0.4mm and the leaf width is 0.055mm; the leaf length of the second type of spinneret is 0.4mm and the leaf width is 0.03mm. The center of all the spinnerets is on the spinneret. There are 4 circles in total, and the spinnerets on each circle are evenly distributed. The circle that appears first from the inside to the outside is marked as the first circle. The diameter of the first circle is 36 mm, and 14 second-class spinnerets are distributed on the first circle. The diameter of the second circle is 49 mm, and 20 second-class spinnerets are distributed on the second circle. The diameter of the third circle is 62 mm, and 28 first-class spinnerets are distributed on the third circle. The diameter of the fourth circle is 75 mm, and 34 first-class spinnerets are distributed on the fourth circle.

[0129] In the spinning assembly, the filter sand used was 180g, 50-70 mesh metal sand; the spinning temperature was 287°C;

[0130] The cooling air pressure of the ring air cooling is 38Pa, the cooling air cylinder length is 49cm, and the slow cooling zone height is 58mm;

[0131] The position of the first pre-network is 132 cm below the spinneret, and the air pressure of the first pre-network is 0.04 MPa;

[0132] The temperature of the first hot roller is 94°C;

[0133] The temperature of the second hot roller is 94°C;

[0134] The speed ratio of the third hot roller to the first hot roller is 2.3;

[0135] The air pressure of the second pre-network is 0.14MPa;

[0136] The air pressure of the main network is 0.6MPa.

[0137] The final sound-insulating polyester FDY fiber has hair distributed on its surface, the length of the hair is 0.8 cm, the hair is curved and the bending radius is 2.5 cm; the breaking strength of the sound-insulating polyester FDY fiber is 3.92 cN / dtex, the elongation at break is 30.4%, the shrinkage rate is 16.7%, the relative radial profile is 32.6%, the oil content is 0.43%, and the hair rate is 95.4%.

[0138] A method for preparing a sound-insulating polyester composite fiber, comprising: passing a polyester POY fiber (specification: 82 dtex / 48 f, with physical indicators: breaking strength: 2.64 cN / dtex, elongation at break: 131.8%, strand unevenness CV value: 1.03%, and oil content: 0.34%) and the sound-insulating polyester FDY fiber prepared in this embodiment in parallel through a pre-net, a first roller, a first hot box, and a cooling plate; then passing the polyester POY fiber through a false twister and then plying the fiber with the sound-insulating polyester FDY fiber on a second roller; and then passing through a net, an auxiliary roller, a second hot box, a third roller, oiling, and winding to obtain the sound-insulating polyester composite fiber;

[0139] Among them, the polyester POY fiber and the sound insulation polyester FDY fiber are both 1 bundle; the temperature of the first hot box is 150°C; the speed of the second roller is 600m / min, the speed ratio of the second roller to the first roller is 1.68, the ratio of the surface linear speed of the friction disk of the false twister to the speed of the second roller is 1.63; the temperature of the second hot box is 185°C.

[0140] The final sound-insulating polyester composite fiber has a breaking strength of 3.39 cN / dtex, an elongation at break of 14.1%, an oil content of 3%, a curl shrinkage of 14.9%, a curl stability of 79.3%, and a hair rate of 96.1%; the sound absorption coefficient a of the fabric made of the sound-insulating polyester composite fiber is 0.4.

[0141] Comparative Example 7

[0142] A method for preparing polyester FDY fiber differs from Example 2 only in that: the centers of all spinnerets are distributed in concentric circles on the spinneret, with a total of four circles. The spinnerets on each circle are evenly distributed. The circle that appears first from the inside out is marked as the first circle. The diameter of the first circle is 36 mm, and 14 second-class spinnerets are distributed on the first circle. The diameter of the second circle is 49 mm, and 20 first-class spinnerets are distributed on the second circle. The diameter of the third circle is 62 mm, and 28 first-class spinnerets are distributed on the third circle. The diameter of the fourth circle is 75 mm, and 34 first-class spinnerets are distributed on the fourth circle.

[0143] A method for preparing a polyester composite fiber is different from Example 2 only in that the sound-insulating polyester FDY fiber prepared in Example 2 is replaced by the polyester FDY fiber prepared in this comparative example.

[0144] The sound absorption coefficient a of the fabric finally made of the polyester composite fiber is 0.08.

[0145] Compared with Example 2, the sound absorption coefficient a of the fabric made of polyester composite fiber in Comparative Example 7 is significantly reduced. This is because the number of the second type of spinneret holes in Comparative Example 7 is too small, that is, the proportion of monofilament B is too low, and sufficient hair cannot be formed, resulting in poor sound absorption effect of the fabric.

[0146] Comparative Example 8

[0147] A method for preparing polyester FDY fiber, which differs from Example 2 only in that the air pressure of the main network is 0.65 MPa.

[0148] Compared with Example 2, the breaking strength of the polyester FDY fiber in Comparative Example 8 is significantly reduced. This is because the main network air pressure is relatively high, which easily blows off the entire bundle of monofilaments B, resulting in a decrease in breaking strength.

[0149] A method for preparing a polyester composite fiber is different from Example 2 only in that the sound-insulating polyester FDY fiber prepared in Example 2 is replaced by the polyester FDY fiber prepared in this comparative example.

[0150] The sound absorption coefficient a of the fabric finally made of the polyester composite fiber is 0.19.

[0151] Compared with Example 2, the sound absorption coefficient a of the fabric made of polyester composite fibers in Comparative Example 8 is significantly reduced. This is because the air pressure of the main network in Comparative Example 8 is too high, and the monofilament B is excessively broken, which affects the strength of the polyester FDY fiber. As a result, when it is subsequently composited with the polyester POY fiber, the monofilament is easily broken, which leads to poor structural stability of the composite fiber and affects the sound absorption effect.

[0152] Comparative Example 9

[0153] A method for preparing polyester composite fibers, which differs from Example 2 only in that the temperature of the first heating box is 145°C.

[0154] The sound absorption coefficient a of the fabric finally made of the polyester composite fiber is 0.18.

[0155] Compared with Example 2, the sound absorption coefficient a of the fabric made of polyester composite fiber in Comparative Example 9 is significantly reduced. This is because the temperature of the first hot box in Comparative Example 9 is too low, and the polyester POY fiber is insufficiently softened. When passing through the false twister subsequently, the hair fibers are more likely to break, affecting the sound absorption effect of the fabric.

[0156] Example 3

[0157] A method for preparing sound-insulating polyester FDY fiber, the overall process flow is: melt extrusion through a metering pump → spinning by a spinning assembly → cooling with annular air → first oiling → first pre-internetting → first godet roller → first heated roller → second heated roller → third heated roller → fourth heated roller → second godet roller → second oiling → second pre-internetting → main internetting → third godet roller → winding and forming;

[0158] The melt preparation process is as follows: slurry preparation → first esterification → second esterification → pre-polycondensation → final polycondensation → polyester melt (intrinsic viscosity 0.625 dL / g); relevant process parameters are: slurry liquid level 69%, the mass of PTA in the slurry accounts for 70% of the total mass of PTA and EG; first esterification temperature 269°C, first esterification pressure 100 kPa, second esterification temperature 275°C, second esterification pressure 35 kPa, pre-polycondensation upper chamber temperature 280°C, pre-polycondensation upper chamber pressure 36 kPa, pre-polycondensation lower chamber temperature 283°C, pre-polycondensation lower chamber pressure 2 kPa, final polycondensation inlet temperature 281°C, final polycondensation outlet temperature 287°C, and final polycondensation vacuum 200 Pa;

[0159] In the spinning assembly, the diameter of the spinneret is 96mm; the spinnerets on the spinneret are divided into two categories, both of which are pentaflobes. The pentaflobes consist of a circle and five long lobes connected to the circle and distributed radially. The diameter of the circle is 0.24mm, and the angle between two adjacent lobes in the pentaflobes is 72°. The leaf length of the first type of spinneret is 0.4mm and the leaf width is 0.055mm; the leaf length of the second type of spinneret is 0.4mm and the leaf width is 0.03mm. The center of all the spinnerets is on the spinneret. There are 4 circles in total, and the spinnerets on each circle are evenly distributed. The circle that appears first from the inside to the outside is marked as the first circle. The diameter of the first circle is 36 mm, and there are 14 second-class spinnerets on the first circle. The diameter of the second circle is 50 mm, and there are 18 second-class spinnerets on the second circle. The diameter of the third circle is 63 mm, and there are 30 first-class spinnerets on the third circle. The diameter of the fourth circle is 76 mm, and there are 34 first-class spinnerets on the fourth circle.

[0160] In the spinning assembly, the filter sand used was 160g of 50-70 mesh metal sand; the spinning temperature was 289°C;

[0161] The cooling air pressure of the ring air cooling is 35Pa, the cooling air cylinder length is 48cm, and the slow cooling zone height is 55mm;

[0162] The position of the first pre-network is 138 cm below the spinneret, and the air pressure of the first pre-network is 0.03 MPa;

[0163] The temperature of the first hot roller is 92°C;

[0164] The temperature of the second hot roller is 92°C;

[0165] The speed ratio of the third hot roller to the first hot roller is 2.5;

[0166] The air pressure of the second pre-network is 0.13MPa;

[0167] The air pressure of the main network is 0.55MPa.

[0168] The final sound-insulating polyester FDY fiber has hair distributed on its surface, the length of the hair is 0.9 cm, the hair is curved and the bending radius is 3.5 cm; the breaking strength of the sound-insulating polyester FDY fiber is 4.14 cN / dtex, the elongation at break is 28.8%, the shrinkage rate is 15.4%, the relative radial profile is 35.4%, the oil content is 0.42%, and the hair rate is 95.1%.

[0169] A method for preparing a sound-insulating polyester composite fiber, comprising: passing a polyester POY fiber (specification: 80 dtex / 72f, with physical indicators: breaking strength: 2.54 cN / dtex, elongation at break: 130.2%, strand unevenness CV value: 1.12%, and oil content: 0.33%) and a sound-insulating polyester FDY fiber prepared in this embodiment through a pre-netting machine, a first roller, a first hot box, and a cooling plate in parallel; then, after passing the polyester POY fiber through a false twister, the fiber is plied with the sound-insulating polyester FDY fiber at a second roller; and then, passing through a netting machine, an auxiliary roller, a second hot box, a third roller, oiling, and winding to obtain the sound-insulating polyester composite fiber;

[0170] Among them, the polyester POY fiber and the sound insulation polyester FDY fiber are both 1 bundle; the temperature of the first hot box is 160°C; the speed of the second roller is 605m / min, the speed ratio of the second roller to the first roller is 1.66, the ratio of the surface linear speed of the friction disk of the false twister to the speed of the second roller is 1.6; the temperature of the second hot box is 175°C.

[0171] The final sound-insulating polyester composite fiber has a breaking strength of 3.45 cN / dtex, an elongation at break of 15.4%, an oil content of 2.8%, a curl shrinkage of 15.2%, a curl stability of 82.2%, and a hair rate of 95.8%; the sound absorption coefficient a of the fabric made of the sound-insulating polyester composite fiber is 0.39.

[0172] Comparative Example 10

[0173] A method for preparing polyester composite fibers, which differs from Example 3 only in that the temperature of the first heating box is 165°C.

[0174] The sound absorption coefficient a of the fabric finally made of the polyester composite fiber is 0.19.

[0175] Compared with Example 3, the sound absorption coefficient a of the fabric made of polyester composite fiber in Comparative Example 10 is significantly reduced. This is because the temperature of the first hot box in Comparative Example 10 is too high, and the hairs of the sound-insulating polyester FDY fiber are easily broken, affecting the sound absorption effect of the fabric.

[0176] Example 4

[0177] A method for preparing sound-insulating polyester FDY fiber, the overall process flow is: melt extrusion through a metering pump → spinning by a spinning assembly → cooling with annular air → first oiling → first pre-internetting → first godet roller → first heated roller → second heated roller → third heated roller → fourth heated roller → second godet roller → second oiling → second pre-internetting → main internetting → third godet roller → winding and forming;

[0178] The melt preparation process is as follows: slurry preparation → first esterification → second esterification → pre-condensation → final condensation → polyester melt (intrinsic viscosity 0.628 dL / g); relevant process parameters are: slurry liquid level 70%, the mass of PTA in the slurry accounts for 71% of the total mass of PTA and EG; first esterification temperature 270°C, first esterification pressure 110 kPa, second esterification temperature 277°C, second esterification pressure 38 kPa, pre-condensation upper chamber temperature 281°C, pre-condensation upper chamber pressure 40 kPa, pre-condensation lower chamber temperature 284°C, pre-condensation lower chamber pressure 2.2 kPa, final condensation inlet temperature 282°C, final condensation outlet temperature 288°C, final condensation vacuum 240 Pa;

[0179] In the spinning assembly, the diameter of the spinneret is 104 mm; the spinnerets on the spinneret are divided into two categories, both of which are pentaflobes. The pentaflobes consist of a circle and five long lobes connected to the circle and distributed radially. The diameter of the circle is 0.23 mm, and the angle between two adjacent lobes in the pentaflobes is 72°. The lobe length of the first type of spinneret is 0.4 mm and the lobe width is 0.055 mm; the lobe length of the second type of spinneret is 0.4 mm and the lobe width is 0.03 mm. The centers of all the spinnerets are distributed in concentric circles on the spinneret, with a total of 5 circles. The spinnerets on each circle are evenly distributed. The circle that appears first from the inside to the outside is marked as the first circle. The diameter of the first circle is 29 mm. There are 12 second-class spinnerets on the first circle. The diameter of the second circle is 43 mm. There are 17 second-class spinnerets on the second circle. The diameter of the third circle is 57 mm. There are 23 second-class spinnerets on the third circle. The diameter of the fourth circle is 71 mm. There are 29 first-class spinnerets on the fourth circle. The diameter of the fifth circle is 85 mm. There are 35 first-class spinnerets on the fifth circle.

[0180] In the spinning assembly, the filter sand is 150g, 50-70 mesh metal sand; the spinning temperature is 290℃;

[0181] The cooling air pressure of the ring air cooling is 40Pa, the cooling air cylinder length is 50cm, and the slow cooling zone height is 60mm;

[0182] The position of the first pre-network is 140 cm below the spinneret, and the air pressure of the first pre-network is 0.03 MPa;

[0183] The temperature of the first hot roller is 90°C;

[0184] The temperature of the second hot roller is 90°C;

[0185] The speed ratio of the third hot roller to the first hot roller is 2.1;

[0186] The air pressure of the second pre-network is 0.1MPa;

[0187] The air pressure of the main network is 0.55MPa.

[0188] The final sound-insulating polyester FDY fiber has hair distributed on its surface, the length of the hair is 1 cm, the hair is curved and the bending radius is 4 cm; the breaking strength of the sound-insulating polyester FDY fiber is 4.01 cN / dtex, the elongation at break is 30.3%, the abnormal shrinkage rate is 15.9%, the relative radial irregularity is 36.7%, the oil content is 0.4%, and the hair rate is 96.3%.

[0189] A method for preparing a sound-insulating polyester composite fiber, comprising: passing a polyester POY fiber (specification: 83 dtex / 72 f, with physical indicators: breaking strength: 2.59 cN / dtex, elongation at break: 130.9%, strand unevenness CV value: 1.14%, and oil content: 0.34%) and the sound-insulating polyester FDY fiber prepared in this embodiment in parallel through a pre-netting machine, a first roller, a first hot box, and a cooling plate; then passing the polyester POY fiber through a false twister and then plying the fiber with the sound-insulating polyester FDY fiber on a second roller; and then passing through a netting machine, an auxiliary roller, a second hot box, a third roller, oiling, and winding to obtain the sound-insulating polyester composite fiber;

[0190] Among them, the polyester POY fiber and the sound insulation polyester FDY fiber are both 1 bundle; the temperature of the first hot box is 155°C; the speed of the second roller is 605m / min, the speed ratio of the second roller to the first roller is 1.66, the ratio of the surface linear speed of the friction disk of the false twister to the speed of the second roller is 1.62; the temperature of the second hot box is 178°C.

[0191] The final sound-insulating polyester composite fiber has a breaking strength of 3.32 cN / dtex, an elongation at break of 15.7%, an oil content of 2.8%, a curl shrinkage of 14.8%, a curl stability of 79.4%, and a hair rate of 96.4%; the sound absorption coefficient a of the fabric made of the sound-insulating polyester composite fiber is 0.49.

[0192] Comparative Example 11

[0193] A method for preparing polyester FDY fiber, the only difference from Example 4 being that the diameter of the spinneret is 70 mm; the diameter of the first circle is 22 mm, the diameter of the second circle is 30 mm, the diameter of the third circle is 38 mm, the diameter of the fourth circle is 46 mm, and the diameter of the fifth circle is 54 mm;

[0194] A method for preparing a polyester composite fiber is different from Example 4 only in that the sound-insulating polyester FDY fiber prepared in Example 4 is replaced by the polyester FDY fiber prepared in this comparative example.

[0195] The sound absorption coefficient a of the fabric finally made of the polyester composite fiber is 0.19.

[0196] Compared with Example 4, the sound absorption coefficient a of the fabric made of polyester composite fiber in Comparative Example 11 is significantly reduced. This is because the diameter of the spinneret in Comparative Example 11 is too low, which slows down the heat dissipation rate of the plate surface, the plate surface temperature is relatively high, the cooling rate is slowed down, and the relative radial profile is reduced. When passing through the main network, it is difficult for the single filament B to form hair, which affects the sound absorption effect of the fabric.

[0197] Example 5

[0198] A method for preparing sound-insulating polyester FDY fibers, which differs from Example 4 only in that all the spinneret holes are distributed on the spinneret plate as follows: Figure 4 As shown, each rhombus in the figure is exactly the same, the side length of the rhombus is 7.8 mm, and the minimum internal angle of the rhombus is 30°.

[0199] The final sound-insulating polyester FDY fiber has hair distributed on its surface, the length of the hair is 0.8 cm, the hair is curved and the bending radius is 3.7 cm; the breaking strength of the sound-insulating polyester FDY fiber is 3.89 cN / dtex, the elongation at break is 29.7%, the abnormal shrinkage rate is 15.2%, the relative radial irregularity is 29.4%, the oil content is 0.39%, and the hair rate is 91.5%.

[0200] A method for preparing a sound-insulating polyester composite fiber, comprising: passing a polyester POY fiber (specification: 88 dtex / 72f, with physical indicators: breaking strength: 2.67 cN / dtex, elongation at break: 131.0%, strand unevenness CV value: 1.09%, and oil content: 0.31%) and a sound-insulating polyester FDY fiber prepared in this embodiment in parallel through a pre-internet, a first roller, a first hot box, and a cooling plate; then passing the polyester POY fiber through a false twister and then plying the fiber with the sound-insulating polyester FDY fiber on a second roller; then passing through an internet, an auxiliary roller, a second hot box, a third roller, oiling, and winding to obtain the sound-insulating polyester composite fiber;

[0201] Among them, the polyester POY fiber and the sound insulation polyester FDY fiber are both 1 bundle; the temperature of the first hot box is 160°C; the speed of the second roller is 610m / min, the speed ratio of the second roller to the first roller is 1.67, the ratio of the surface linear speed of the friction disk of the false twister to the speed of the second roller is 1.64; the temperature of the second hot box is 182°C.

[0202] The final sound-insulating polyester composite fiber has a breaking strength of 3.39 cN / dtex, an elongation at break of 14.6%, an oil content of 2.8%, a curl shrinkage of 14.3%, a curl stability of 78.6%, and a hair rate of 92.9%; the sound absorption coefficient a of the fabric made of the sound-insulating polyester composite fiber is 0.23.

[0203] Example 6

[0204] A method for preparing sound-insulating polyester FDY fiber, which differs from Example 4 only in that the mesh size of the metal sand is 70-90.

[0205] The final sound-insulating polyester FDY fiber has hair distributed on its surface, the length of the hair is 1.0 cm, the hair is curved and the bending radius is 3.9 cm; the breaking strength of the sound-insulating polyester FDY fiber is 4.07 cN / dtex, the elongation at break is 30.1%, the abnormal shrinkage rate is 15.8%, the relative radial irregularity is 24.7%, the oil content is 0.4%, and the hair rate is 93.1%.

[0206] A method for preparing a sound-insulating polyester composite fiber, comprising: passing a polyester POY fiber (specification: 83 dtex / 72 f, with physical indicators: breaking strength: 2.59 cN / dtex, elongation at break: 130.9%, strand unevenness CV value: 1.14%, and oil content: 0.34%) and the sound-insulating polyester FDY fiber prepared in this embodiment in parallel through a pre-netting machine, a first roller, a first hot box, and a cooling plate; then passing the polyester POY fiber through a false twister and then plying the fiber with the sound-insulating polyester FDY fiber on a second roller; and then passing through a netting machine, an auxiliary roller, a second hot box, a third roller, oiling, and winding to obtain the sound-insulating polyester composite fiber;

[0207] Among them, the polyester POY fiber and the sound insulation polyester FDY fiber are both 1 bundle; the temperature of the first hot box is 157°C; the speed of the second roller is 605m / min, the speed ratio of the second roller to the first roller is 1.66, the ratio of the surface linear speed of the friction disk of the false twister to the speed of the second roller is 1.64; the temperature of the second hot box is 185°C.

[0208] The final sound-insulating polyester composite fiber has a breaking strength of 3.34 cN / dtex, an elongation at break of 15.9%, an oil content of 2.9%, a curl shrinkage of 15.7%, a curl stability of 82%, and a hair rate of 93.7%; the sound absorption coefficient a of the fabric made of the sound-insulating polyester composite fiber is 0.27.

[0209] Example 7

[0210] A method for preparing sound-insulating polyester FDY fiber, which differs from Example 4 only in that the spinning temperature is 295°C.

[0211] The final sound-insulating polyester FDY fiber has hair distributed on its surface, the length of the hair is 0.9 cm, the hair is curved and the bending radius is 3.9 cm; the breaking strength of the sound-insulating polyester FDY fiber is 4.01 cN / dtex, the elongation at break is 30.5%, the abnormal shrinkage rate is 15.8%, the relative radial irregularity is 25.4%, the oil content is 0.4%, and the hair rate is 91.7%.

[0212] A method for preparing a sound-insulating polyester composite fiber, comprising: passing a polyester POY fiber (specification: 83 dtex / 72 f, with physical indicators: breaking strength: 2.59 cN / dtex, elongation at break: 130.9%, strand unevenness CV value: 1.14%, and oil content: 0.34%) and the sound-insulating polyester FDY fiber prepared in this embodiment in parallel through a pre-netting machine, a first roller, a first hot box, and a cooling plate; then passing the polyester POY fiber through a false twister and then plying the fiber with the sound-insulating polyester FDY fiber on a second roller; and then passing through a netting machine, an auxiliary roller, a second hot box, a third roller, oiling, and winding to obtain the sound-insulating polyester composite fiber;

[0213] Among them, the polyester POY fiber and the sound insulation polyester FDY fiber are both 1 bundle; the temperature of the first hot box is 154°C; the speed of the second roller is 605m / min, the speed ratio of the second roller to the first roller is 1.66, the ratio of the surface linear speed of the friction disk of the false twister to the speed of the second roller is 1.6; the temperature of the second hot box is 180°C.

[0214] The final sound-insulating polyester composite fiber has a breaking strength of 3.37 cN / dtex, an elongation at break of 15.2%, an oil content of 2.8%, a curl shrinkage of 15.4%, a curl stability of 81.9%, and a hair rate of 91.6%; the sound absorption coefficient a of the fabric made of the sound-insulating polyester composite fiber is 0.27.

[0215] Example 8

[0216] A method for preparing sound-insulating polyester FDY fiber, which differs from Example 4 only in that the cooling air pressure of the annular air cooling is 45 Pa.

[0217] The final sound-insulating polyester FDY fiber has hair distributed on its surface, the length of the hair is 1.0 cm, the hair is curved and the bending radius is 3.9 cm; the breaking strength of the sound-insulating polyester FDY fiber is 4.03 cN / dtex, the elongation at break is 29.8%, the shrinkage rate is 12.4%, the relative radial profile is 38.4%, the oil content is 0.40%, and the hair rate is 94.8%.

[0218] A method for preparing a sound-insulating polyester composite fiber, comprising: passing a polyester POY fiber (specification: 80 dtex / 72f, with physical indicators: breaking strength: 2.54 cN / dtex, elongation at break: 130.2%, strand unevenness CV value: 1.12%, and oil content: 0.33%) and a sound-insulating polyester FDY fiber prepared in this embodiment through a pre-netting machine, a first roller, a first hot box, and a cooling plate in parallel; then, after passing the polyester POY fiber through a false twister, the fiber is plied with the sound-insulating polyester FDY fiber at a second roller; and then, passing through a netting machine, an auxiliary roller, a second hot box, a third roller, oiling, and winding to obtain the sound-insulating polyester composite fiber;

[0219] Among them, the polyester POY fiber and the sound insulation polyester FDY fiber are both 1 bundle; the temperature of the first hot box is 155°C; the speed of the second roller is 620m / min, the speed ratio of the second roller to the first roller is 1.65, the ratio of the surface linear speed of the friction disk of the false twister to the speed of the second roller is 1.64; the temperature of the second hot box is 182°C.

[0220] The final sound-insulating polyester composite fiber has a breaking strength of 3.39 cN / dtex, an elongation at break of 15.7%, an oil content of 3.2%, a curl shrinkage of 14.6%, a curl stability of 80.3%, and a hair rate of 94.1%; the sound absorption coefficient a of the fabric made of the sound-insulating polyester composite fiber is 0.31.

[0221] Example 9

[0222] A method for preparing sound-insulating polyester FDY fiber, which differs from Example 4 only in that the cooling air cylinder for annular air cooling is 52 cm long.

[0223] The final sound-insulating polyester FDY fiber has hair distributed on its surface, the length of the hair is 1.0 cm, the hair is curved and the bending radius is 3.9 cm; the breaking strength of the sound-insulating polyester FDY fiber is 4.06 cN / dtex, the elongation at break is 29.9%, the shrinkage rate is 13.7%, the relative radial profile is 36.8%, the oil content is 0.40%, and the hair rate is 93.1%.

[0224] A method for preparing a sound-insulating polyester composite fiber, comprising: passing a polyester POY fiber (specification: 80 dtex / 72f, with physical indicators: breaking strength: 2.54 cN / dtex, elongation at break: 130.2%, strand unevenness CV value: 1.12%, and oil content: 0.33%) and a sound-insulating polyester FDY fiber prepared in this embodiment through a pre-netting machine, a first roller, a first hot box, and a cooling plate in parallel; then, after passing the polyester POY fiber through a false twister, the fiber is plied with the sound-insulating polyester FDY fiber at a second roller; and then, passing through a netting machine, an auxiliary roller, a second hot box, a third roller, oiling, and winding to obtain the sound-insulating polyester composite fiber;

[0225] Among them, the polyester POY fiber and the sound insulation polyester FDY fiber are both 1 bundle; the temperature of the first hot box is 160°C; the speed of the second roller is 620m / min, the speed ratio of the second roller to the first roller is 1.65, the ratio of the surface linear speed of the friction disk of the false twister to the speed of the second roller is 1.65; the temperature of the second hot box is 181°C.

[0226] The final sound-insulating polyester composite fiber has a breaking strength of 3.42 cN / dtex, an elongation at break of 15.6%, an oil content of 2.9%, a curl shrinkage of 14.3%, a curl stability of 81.6%, and a hair rate of 94.6%; the sound absorption coefficient a of the fabric made of the sound-insulating polyester composite fiber is 0.26.

[0227] Example 10

[0228] A method for preparing sound-insulating polyester FDY fiber, which differs from Example 4 only in that the height of the slow cooling zone of the annular air cooling is 65 mm.

[0229] The final sound-insulating polyester FDY fiber has hair distributed on its surface, the length of the hair is 1.0 cm, the hair is curved and the bending radius is 3.9 cm; the breaking strength of the sound-insulating polyester FDY fiber is 4.06 cN / dtex, the elongation at break is 29.9%, the abnormal shrinkage rate is 15.1%, the relative radial irregularity is 31.2%, the oil content is 0.40%, and the hair rate is 93.7%.

[0230] A method for preparing a sound-insulating polyester composite fiber, comprising: passing a polyester POY fiber (specification: 88 dtex / 72f, with physical indicators: breaking strength: 2.67 cN / dtex, elongation at break: 131.0%, strand unevenness CV value: 1.09%, and oil content: 0.31%) and a sound-insulating polyester FDY fiber prepared in this embodiment in parallel through a pre-internet, a first roller, a first hot box, and a cooling plate; then passing the polyester POY fiber through a false twister and then plying the fiber with the sound-insulating polyester FDY fiber on a second roller; then passing through an internet, an auxiliary roller, a second hot box, a third roller, oiling, and winding to obtain the sound-insulating polyester composite fiber;

[0231] Among them, the polyester POY fiber and the sound insulation polyester FDY fiber are both 1 bundle; the temperature of the first hot box is 158°C; the speed of the second roller is 605m / min, the speed ratio of the second roller to the first roller is 1.67, the ratio of the surface linear speed of the friction disk of the false twister to the speed of the second roller is 1.62; the temperature of the second hot box is 183°C.

[0232] The final sound-insulating polyester composite fiber has a breaking strength of 3.39 cN / dtex, an elongation at break of 14.3%, an oil content of 3%, a curl shrinkage of 15%, a curl stability of 82.5%, and a hair rate of 94.7%; the sound absorption coefficient a of the fabric made of the sound-insulating polyester composite fiber is 0.25.

[0233] Example 11

[0234] A method for preparing sound-insulating polyester FDY fiber, which differs from Example 4 only in that the speed ratio of the third hot roller to the first hot roller is 2.0.

[0235] The final sound-insulating polyester FDY fiber has hair distributed on its surface, the length of the hair is 1.0 cm, the hair is curved and the bending radius is 3.9 cm; the breaking strength of the sound-insulating polyester FDY fiber is 3.84 cN / dtex, the elongation at break is 32.7%, the shrinkage rate is 15.6%, the relative radial profile is 36.1%, the oil content is 0.40%, and the hair rate is 93.3%.

[0236] A method for preparing a sound-insulating polyester composite fiber, comprising: passing a polyester POY fiber (specification: 88 dtex / 72f, with physical indicators: breaking strength: 2.67 cN / dtex, elongation at break: 131.0%, strand unevenness CV value: 1.09%, and oil content: 0.31%) and a sound-insulating polyester FDY fiber prepared in this embodiment in parallel through a pre-internet, a first roller, a first hot box, and a cooling plate; then passing the polyester POY fiber through a false twister and then plying the fiber with the sound-insulating polyester FDY fiber on a second roller; then passing through an internet, an auxiliary roller, a second hot box, a third roller, oiling, and winding to obtain the sound-insulating polyester composite fiber;

[0237] Among them, the polyester POY fiber and the sound insulation polyester FDY fiber are both 1 bundle; the temperature of the first hot box is 157°C; the speed of the second roller is 610m / min, the speed ratio of the second roller to the first roller is 1.68, the ratio of the surface linear speed of the friction disk of the false twister to the speed of the second roller is 1.63; the temperature of the second hot box is 180°C.

[0238] The final sound-insulating polyester composite fiber has a breaking strength of 3.6 cN / dtex, an elongation at break of 14.3%, an oil content of 2.8%, a curl shrinkage of 14.8%, a curl stability of 80.4%, and a hair rate of 92.1%; the sound absorption coefficient a of the fabric made of the sound-insulating polyester composite fiber is 0.22.

Claims

1. A method for preparing sound-insulating polyester FDY fiber, comprising a spinning assembly spinning process, a ring-blowing cooling process, a stretching process, a shaping process, and a main intertwining process, characterized in that: In the spinning assembly, the number of spinnerets on the spinneret ranges from 96 to 144 and is divided into two categories; Both types of spinnerets are pentaflobes, which consist of a circle and five long lobes connected to the circle and distributed radially. The diameter of the circle is 0.23±0.01mm, and the angle between two adjacent lobes is 72°. The leaf length of the first type of spinneret is 0.4 mm and the leaf width is 0.055 mm; the leaf length of the second type of spinneret is 0.4 mm and the leaf width is 0.03 mm; The ratio of the number of the first type of spinnerets to the number of the second type of spinnerets is 1-2:1; The diameter of the spinneret is 95-105 mm; Stretching is completed by the first hot roller, the second hot roller and the third hot roller. The temperature of the first hot roller and the second hot roller is 90-94℃. The shaping is completed by the third and fourth hot rollers; The air pressure of the main network is 0.55-0.6MPa.

2. The method for preparing a sound-insulating polyester FDY fiber according to claim 1, characterized in that: All the spinnerets are distributed in concentric circles on the spinneret, the first type of spinnerets are arranged in the outer circle of the spinneret, and the second type of spinnerets are arranged in the inner circle of the spinneret.

3. The method for preparing a sound-insulating polyester FDY fiber according to claim 1, characterized in that: In the spinning assembly, the filter sand is 150-180g, 50-70 mesh metal sand.

4. The method for preparing a sound-insulating polyester FDY fiber according to claim 1, characterized in that: The spinning temperature is 286-290℃.

5. The method for preparing a sound-insulating polyester FDY fiber according to claim 1, characterized in that: The cooling air pressure of the ring air cooling is 35-40Pa, the length of the cooling air cylinder is 48-50cm, and the height of the slow cooling zone is 55-60mm.

6. The method for preparing a sound-insulating polyester FDY fiber according to claim 1, characterized in that: The rotation speed ratio of the third hot roller to the first hot roller is 2.0-2.

5.

7. The method for preparing sound-insulating polyester FDY fiber according to claim 1, characterized in that: The overall process flow is: melt is extruded through a metering pump → spinning by a spinning assembly → cooling by annular air → first oiling → first pre-network → first godet roller → first hot roller → second hot roller → third hot roller → fourth hot roller → second godet roller → second oiling → second pre-network → main network → third godet roller → winding and forming.

8. The method for preparing sound-insulating polyester FDY fiber according to claim 7, characterized in that: The position of the first pre-network is 130-140 cm below the spinneret, the air pressure of the first pre-network is 0.03-0.04 MPa, and the air pressure of the second pre-network is 0.1-0.15 MPa.

9. The sound-insulating polyester FDY fiber prepared by the method for preparing the sound-insulating polyester FDY fiber according to any one of claims 1 to 8, characterized in that: There are hairs distributed on the surface, the length of the hairs is 0.5-1.0 cm, the hairs are curved and the bending radius is 2-4 cm; the breaking strength of the sound-insulating polyester FDY fiber is ≥3.84 cN / dtex, the elongation at break is 28.8-32.7%, the abnormal shrinkage rate is 12.4-18.2%, the relative radial irregularity is ≥24.7%, the oil content is 0.39-0.45%, and the hair rate is ≥91.5%.

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