Hollow ES fiber production process

Abstract

The invention relates to a hollow ES (Ethylene-Propylene-Styrene) fiber production process which comprises the following steps: (1) respectively drying and preheating a skin layer raw material and a core layer raw material, and feeding into a screw extruder for melt blending; (2) conveying the melt-blended material to a spinning box, extruding the melt-blended material through a skin-core composite spinneret plate to form nascent fibers, and introducing compressed air with the pressure of 200-300Pa into a core layer channel of the spinneret plate to form a hollow structure; (3) the formed nascent fibers are sequentially subjected to heat preservation treatment and stepped slow cooling treatment, then first-time drafting is carried out, and the first-time drafting multiple is 1.5-2.5 times; (4) the fibers subjected to primary stretching are introduced into a steam box to be evenly heated and softened, then secondary stretching is conducted, and the secondary stretching multiple is 1.2-1.5 times; (5) applying controllable tension to the fibers subjected to secondary drafting for heat setting; and (6) winding. The method is reasonable in design, the technological process is shortened, the pollution risk is effectively reduced, and the fiber forming quality is improved.

Description

Technical Field

[0001] This invention relates to a hollow ES fiber production process. Background Technology

[0002] ES fiber, a heat-bonding composite fiber with a core-sheath structure, is widely used in high-end hygiene materials (such as diapers and sanitary napkins), medical supplies, filter materials, and high-grade sound and heat insulation materials because it can be formed through heat treatment without chemical adhesives. Its low-melting-point component (such as polyethylene) in the sheath and high-melting-point component (such as polyester) in the core endow the fiber with excellent thermal bonding and mechanical properties.

[0003] Currently, the mainstream technology for producing ES fibers both domestically and internationally is the "two-step method": the first step involves spinning to obtain raw yarn, and the second step involves bundling the raw yarn from multiple yarn containers and then subjecting it to multiple processes such as oil impregnation, multiple water baths and steam drawing, drying and setting, and cutting. This traditional method has significant drawbacks: the process flow is long, the equipment occupies a large area, and the investment cost is high; the fibers are transferred between different processes, and have long contact time with equipment (especially water-containing drawing equipment) and air, making them susceptible to contamination and affecting the cleanliness and quality of the final product; in addition, the multi-step processing leads to high energy consumption, which is inconsistent with the development trend of green manufacturing.

[0004] Furthermore, in the current ES fiber production process, after the fibers are ejected from the spinneret, they are cooled directly by methods such as air cooling or water cooling. This cooling method causes the fibers to be suddenly cooled after being ejected from the spinneret holes, which can easily lead to poor fiber forming quality. Summary of the Invention

[0005] The present invention addresses the problems existing in the prior art, namely, the technical problem to be solved by the present invention is to provide a hollow ES fiber production process.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a hollow ES fiber production process, comprising the following steps: (1) Raw material pretreatment and mixing: After drying and preheating the skin layer raw material and the core layer raw material respectively, they are fed into the screw extruder by metering pump in proportion for melt blending; (2) Melt spinning: The melt-blended material is transported to the spinning box and extruded into nascent fibers through a core-sheath composite spinneret. Compressed air with a pressure of 200-300 Pa is introduced into the core channel of the spinneret to form a hollow structure. (3) Gradient cooling and initial stretching: The nascent fibers after molding are subjected to heat preservation treatment and step-by-step slow cooling treatment in sequence, followed by the first stretching, with the first stretching ratio being 1.5-2.5 times; (4) Steam heating and secondary stretching: The fibers that have undergone the first stretching are introduced into the steam box for uniform heating and softening, and then a second stretching is performed. The second stretching ratio is 1.2-1.5 times. (5) Tension setting and oiling: Apply controllable tension to the fibers after secondary stretching for heat setting, and apply spinning oil evenly through an oiling device; (6) Winding: The processed fibers are wound into a filament cake by a winding machine.

[0007] Furthermore, in step (1), the raw material of the skin layer is low-melting-point polyethylene with a melting point of 110-130℃; the raw material of the core layer is high-melting-point polyethylene terephthalate with a melting point of 240-260℃; and the mass ratio of the skin layer to the core layer is (30:70) to (50:50).

[0008] Furthermore, in step (1), the core material contains 0.5%-2% inorganic nanofiller and 0.5%-1.5% hydrophilic finishing agent, which are added to the total mass of the core material; the inorganic nanofiller is calcium carbonate powder with a particle size of 20-50 μm.

[0009] Furthermore, in step (3), heat preservation is performed by a heat preservation device, which includes a liftable box set below the spinneret. The liftable box has several heat preservation hot water chambers inside, and the water temperature of the several heat preservation hot water chambers decreases sequentially from top to bottom. Several threading channels are vertically connected between the several heat preservation hot water chambers. The multiple threading channels correspond to multiple spinneret holes on the spinneret. The fiber output from each spinneret hole on the spinneret passes through the threading channel corresponding to its position. The hot water in each heat preservation hot water chamber heats and preserves the fiber through the threading channel.

[0010] Furthermore, each insulated hot water chamber is equipped with a heating component, and each heating component in the insulated hot water chamber is electrically connected to a temperature control component to control the temperature of the hot water in the insulated hot water chamber; a cooling water chamber is provided directly below several insulated hot water chambers inside the liftable box, and a refrigeration component is provided in the cooling water chamber; multiple wire threading channels penetrate the cooling water chamber vertically.

[0011] Furthermore, it also includes a lifting assembly, which includes lifting cylinders symmetrically arranged on the left and right sides of the liftable box. The lifting cylinders are vertically arranged, with the cylinder rods extending downwards and the ends fixed with lifting connecting blocks. The lifting connecting blocks are fixedly connected to the liftable box. The lifting cylinders drive the liftable box to rise and fall through the lifting connecting blocks, so as to achieve contact or separation between the liftable box and the bottom of the spinning box. When the liftable box is separated from the spinning box, it can make way for the horizontal rotation of the rotatable cleaning component.

[0012] Furthermore, a rotatable cleaning assembly is provided around the spinning box. The rotatable cleaning assembly rotates to a position directly below the spinneret and cleans the spinneret. The rotatable cleaning assembly includes a rotating rod horizontally positioned below the right side of the spinning box. Cleaning brushes are evenly distributed along the length of the top of the rotating rod. The rotating rod is driven to rotate in the horizontal plane by a first rotating motor installed on the right side wall of the spinning box.

[0013] Furthermore, a first suction hood is horizontally arranged on the right side of the first rotary motor. The bottom of the first suction hood is open and serves as a suction port. The top of the first suction hood is connected to the vacuum cleaner via a first suction pipe. The rotating rod is initially parallel and located directly below the first suction hood. The rotatable cleaning assembly also includes a second suction hood horizontally arranged below the left side of the spinning box. The top of the second suction hood is open and serves as a suction port. The second suction hood is driven to rotate in the horizontal plane by a second rotary motor installed on the left side wall of the spinning box. One end of the second suction hood is connected to a second suction pipe via a rotating connector. The second suction pipe is connected to the vacuum cleaner.

[0014] Furthermore, in step (3), the gradient cooling adopts a ring blowing device, and the cooling air temperature is gradually reduced from 50-60℃ to 30-40℃ along the fiber conveying direction, and the cooling air speed is controlled at 0.3-0.8m / s.

[0015] Furthermore, in step (4), the steam box is equipped with multiple adjustable steam nozzles, the steam temperature is controlled at 105-125℃, and the steam saturation in the box is maintained at 85%-95%.

[0016] Compared with the prior art, the present invention has the following advantages: The present invention is reasonably designed and the continuous short-process production shortens the process flow. Moreover, the fiber is continuously produced in a closed or semi-closed system, which greatly shortens the contact time with the external environment and effectively reduces the risk of pollution. By first heat-insulating the fiber output from the spinneret, the sudden cooling of the fiber after it is ejected is prevented, which would cause stress deformation of the fiber due to external cold and internal heat, thereby improving the fiber forming quality. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the process flow of the present invention; Figure 2 This is a schematic diagram of the front cross-sectional structure of the heat preservation device in this invention; Figure 3 yes Figure 2 A schematic diagram of the local structure in the diagram; Figure 4 yes Figure 3 Local structural diagram Figure 1 ; Figure 5 yes Figure 3Local structural diagram Figure 2 ; Figure 6 This is a schematic diagram of the working state of the cleaning mechanism in this invention. Figure 1 ; Figure 7 yes Figure 6 A schematic diagram of the local structure in the diagram; Figure 8 This is a schematic diagram of the working state of the cleaning mechanism in this invention. Figure 2 ; Figure 9 yes Figure 8 A schematic diagram of a local structure. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0019] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0020] like Figure 1 As shown, this invention discloses a hollow ES fiber production process, aiming to transform the traditional "two-step method" into a highly integrated "one-step" continuous production line. This production process includes the following steps: (1) Raw material pretreatment and mixing: After drying and preheating the skin layer raw material and the core layer raw material respectively, they are fed into the screw extruder by metering pump in proportion for melt blending; (2) Melt spinning: The melt-blended material is transported to the spinning box and extruded into nascent fibers through a core-sheath composite spinneret. Compressed air with a pressure of 200-300 Pa is introduced into the core channel of the spinneret to form a hollow structure. (3) Gradient cooling and initial stretching: The nascent fibers after molding are subjected to heat preservation treatment and step-by-step slow cooling treatment in sequence, followed by the first stretching, with the first stretching ratio being 1.5-2.5 times; (4) Steam heating and secondary stretching: The fibers that have undergone the first stretching are introduced into the steam box for uniform heating and softening, and then a second stretching is performed. The second stretching ratio is 1.2-1.5 times. (5) Tension setting and oiling: Apply controllable tension to the fibers after secondary stretching for heat setting, and apply spinning oil evenly through an oiling device; (6) Winding: The processed fibers are wound into a filament cake by a winding machine.

[0021] Preferably, the core channel pressure of the spinneret is 250 Pa.

[0022] By employing a process of heat preservation, slow cooling, stretching, steam softening, and secondary stretching, and by precisely controlling the temperature, wind speed, and stretching ratio, the fiber macromolecular chains are fully oriented and crystallized, thereby obtaining a high-strength and stable hollow morphology.

[0023] Specifically, in step (1), the raw material of the skin layer is low-melting-point polyethylene with a melting point of 110-130℃; the raw material of the core layer is high-melting-point polyethylene terephthalate with a melting point of 240-260℃; and the mass ratio of the skin layer to the core layer is (30:70) to (50:50).

[0024] Specifically, in step (1), the core material contains 0.5%-2% inorganic nanofiller and 0.5%-1.5% hydrophilic finishing agent. The inorganic nanofiller is calcium carbonate powder with a particle size of 20-50 μm.

[0025] Specifically, in step (3), heat preservation is performed using a heat preservation device, such as... Figures 2-9 As shown, the heat preservation device includes a liftable housing located below the spinneret 2. The spinneret 2 is located at the bottom of the spinning box 1. The liftable housing 3 has three heat-preserving hot water chambers 4 inside. The water temperature in the three heat-preserving hot water chambers 4 decreases sequentially from top to bottom, forming a gradient change in heat preservation temperature along the vertical direction. Multiple threading channels 5 extend vertically between the three heat-preserving hot water chambers 4. These multiple threading channels 5 correspond to multiple spinneret holes on the spinneret 2. The fiber filaments 6 output from each spinneret hole on the spinneret 2 pass through the corresponding threading channel 5. The hot water in each heat-preserving hot water chamber 4 heats and preserves the fiber filaments 6 through the threading channels 5. Specifically, the heat from the hot water in the heat-preserving hot water chamber is transferred to the threading channels, and the heat from the threading channels dissipates into the interior, contacting the fiber filaments, thus achieving heat preservation of the fiber filaments. By setting several vertically distributed insulated hot water chambers below the spinneret, the hot water in the chambers heats the fibers sequentially as they pass through the threading channel. This provides insulation after the fibers are ejected, preventing them from suddenly cooling down and causing stress deformation due to external cold and internal heat. Furthermore, since the water temperature in the chambers decreases sequentially from top to bottom, the insulation temperature of the fibers gradually decreases, effectively preventing the fibers from cooling at a high temperature later on, further reducing stress deformation.

[0026] Specifically, in the insulation device, each insulated hot water chamber 4 is equipped with a heating component, and each heating component in the insulated hot water chamber 4 is electrically connected to a temperature control component to control the temperature of the hot water in the insulated hot water chamber. Specifically, the heating component is an electric heating plate 8 installed on the side wall of the insulated hot water chamber 4. The temperature control component includes a temperature sensor and a control unit. The temperature sensor and the electric heating plate are electrically connected to the control unit. The temperature sensor detects the water temperature in the insulated hot water chamber, and the control unit controls the electric heating plate based on the signal from the temperature sensor.

[0027] Specifically, in the insulation device, a cooling water chamber 9 is located directly below the three insulated hot water chambers 4 inside the liftable housing 3. A refrigeration component is installed inside the cooling water chamber 9. Multiple threading channels 5 vertically penetrate the cooling water chamber 9. During operation, the refrigeration component cools the water in the cooling water chamber. When the fiber passes through the cooling water chamber in the threading channel, the heat on the fiber is transferred to the threading channel, and the heat on the threading channel is transferred to the cooling water, thus cooling the fiber.

[0028] Because the fiber filaments are located in the threading channel when passing through the liftable housing, they do not come into direct contact with the hot water in the insulated hot water chamber or the cold water in the cooling water chamber. This forms a non-contact heating and cooling system, effectively preventing the heating or cooling medium from coming into direct contact with the fiber filaments. This makes the heating and cooling of the fiber filaments more gentle, less prone to sudden temperature changes, and reduces stress deformation.

[0029] Specifically, the insulation device also includes a lifting assembly, which includes lifting cylinders 10 symmetrically arranged on the left and right sides of the liftable housing 3. The lifting cylinders 10 are vertically arranged, with the cylinder rods of the lifting cylinders 10 extending downwards and the ends fixed with lifting connecting blocks 11. The lifting connecting blocks 11 are fixedly connected to the liftable housing 3. The lifting cylinders 10 drive the liftable housing 3 to rise and fall through the lifting connecting blocks 11, so as to achieve contact or separation between the liftable housing and the bottom of the spinning box. When the liftable housing moves to contact the bottom of the spinning box, each threading channel corresponds to a spinneret hole, and the fiber filaments ejected from the spinneret directly enter the threading channel. When the liftable housing separates from the spinning box, the spinneret is in a non-working state, which allows for the horizontal rotation of the rotatable cleaning assembly.

[0030] Specifically, in the heat preservation device, a rotatable cleaning component 7 is provided around the spinning box 1. The rotatable cleaning component 7 rotates to directly below the spinneret 2 and cleans the spinneret 2. The rotatable cleaning component can clean the spinneret by rotating when not in operation, which is more convenient and efficient than the traditional manual cleaning method.

[0031] Specifically, the rotatable cleaning assembly 7 includes a rotating rod 13 horizontally positioned below the right side of the spinning box 1. Cleaning brushes 14 are evenly distributed along the length of the top of the rotating rod 13. The rotating rod 13 is driven to rotate in a horizontal plane by a first rotating motor 15 mounted on the right side wall of the spinning box 1. During operation, the first rotating motor drives the rotating rod and cleaning brushes to rotate in a horizontal plane. The cleaning brushes clean the spinneret holes on the spinneret plate, removing or carrying away fiber waste remaining in the spinneret holes, thus achieving cleaning.

[0032] Specifically, a first suction cover 16 is horizontally arranged on the right side of the first rotary motor 15. The bottom of the first suction cover 16 is open and serves as a suction port. The top of the first suction cover 16 is connected to the vacuum cleaner through a first suction pipe 17. The rotating rod 13 is initially parallel and located directly below the first suction cover 16. After the cleaning brush rotates several times to complete the cleaning, the rotating rod rotates back to its initial state, at which point it is located directly below the first suction cover. The vacuum cleaner then sucks up the first suction cover, removing the fiber waste remaining on the cleaning brush and preventing it from affecting the next cleaning of the spinneret by the cleaning brush.

[0033] Specifically, the rotatable cleaning assembly 7 further includes a second suction hood 18 horizontally positioned below the left side of the spinning box 1. The top of the second suction hood 18 is open and serves as a suction port. The second suction hood 18 is driven to rotate in the horizontal plane by a second rotary motor 19 installed on the left side wall of the spinning box 1. One end of the second suction hood 18 is connected to a second suction pipe 20 via a rotary connector, and the second suction pipe 20 is connected to a vacuum cleaner. After the cleaning brush cleans the spinneret, the second rotary motor drives the second suction hood to rotate in the horizontal plane. When the second suction hood rotates past the spinneret, the vacuum cleaner removes the remaining fiber waste on the spinneret through the second suction hood, achieving secondary cleaning and effectively improving the cleaning effect on the spinneret.

[0034] Specifically, in step (3), gradient cooling is achieved using a ring-blowing device, with the cooling air temperature gradually decreasing from 50-60℃ to 30-40℃ along the fiber conveying direction, and the cooling air velocity controlled at 0.3-0.8m / s.

[0035] Specifically, in step (4), the steam box is equipped with multiple adjustable steam nozzles, the steam temperature is controlled at 105-125℃, and the steam saturation in the box is maintained at 85%-95%.

[0036] The fibers produced by this process have a hollowness of 10%-15% and a fineness of 0.5-3.0 dtex.

[0037] Example 1, taking the production of 0.8 dtex high-medium hollow ES short fibers as an example: (1) Raw material preparation: The sheath layer uses low-melting-point polyethylene (LDPE) with a melting point of 120℃, and the core layer uses polyethylene terephthalate (PET) with a melting point of 250℃. 1% hydrophilic finishing agent (composed of sodium dioctyl sulfonate and other compounds) and 3% nano-calcium carbonate (particle size approximately 30μm) are added to the PET core layer. The mass ratio of the sheath layer to the core layer is 40:60. (2) Melt spinning: The sheath layer and core layer raw materials are melted separately by a screw extruder and then spun through a sheath-core composite spinneret (250Pa compressed air is introduced into the core layer). The spinning temperature is set as follows: 150℃ for the LDPE section and 270℃ for the PET section. (3) Gradient cooling and initial stretching: The nascent fibers are first heat-insulated, then cooled by ring blowing at a speed of 0.5m / s, with the air temperature gradually decreasing from 55℃ to 35℃. The first stretching is then performed, with a stretching ratio of 2.0 times. (4) Steam drawing and secondary stretching: The fiber is introduced into a steam chamber (steam temperature 115℃, saturation 90%) for heating and softening, followed by a second drawing with a stretch ratio of 1.3 times. (5) Tension setting and oiling: The fiber after secondary drawing is subjected to controllable tension for heat setting at 100℃, and spinning oil is applied evenly through an oiling device. (6) Winding: The processed fiber is wound into a yarn cake by a winding machine.

[0038] Testing revealed that the fiber obtained in Example 1 had a hollowness of 12%, a fineness of 0.8 dtex, was white, and had a soft feel, meeting the standards for high-end sanitary material raw materials.

[0039] Comparative example: Production of similar ES fibers using the traditional two-step method: Spinning and post-spinning drawing are carried out according to the traditional process, which involves a long equipment process and the fibers pass through open environments such as water baths.

[0040] Results Comparison: The fiber prepared in Example 1 of this invention is superior to the comparative product in terms of cleanliness (number of impurity points) and strength variation coefficient.

[0041] The advantages of this invention are: (1) Through integrated design, a large number of equipment such as feeders, bundle racks, and multi-track drawing machines are eliminated, which greatly reduces investment and operating costs; (2) Continuous short-process production reduces energy consumption in intermediate links, effectively reducing production energy consumption; (3) The fiber is produced continuously in a closed or semi-closed system, which greatly shortens the contact time with the external environment and effectively reduces the risk of pollution. (4) By optimizing the spinneret design, compressed air pressure and drawing process, the hollowness of the fiber is kept stable within the ideal range of 10%-15%, resulting in excellent product performance; (5) By setting several vertically distributed heat-insulating hot water chambers below the spinneret, when the fiber filaments ejected from the spinneret pass through the threading channel downwards, the hot water in the several heat-insulating hot water chambers heats the fiber filaments in sequence, realizing heat preservation treatment after the fiber filaments are ejected, preventing the fiber filaments from suddenly encountering cold after being ejected, which would lead to stress deformation caused by the fiber filaments being cold on the outside and hot on the inside; and since the water temperature of the several heat-insulating hot water chambers decreases from top to bottom, the heat preservation temperature of the fiber filaments gradually decreases, effectively avoiding the fiber filaments from being cooled at a high temperature afterwards, further reducing stress deformation; the rotatable cleaning component can clean the spinneret by rotating when not in use, which is more convenient and efficient than the traditional manual cleaning method.

[0042] If this invention discloses or relates to components or structural parts that are fixedly connected to each other, then, unless otherwise stated, a fixed connection can be understood as: a fixed connection that can be detached (e.g., using bolts or screws), or a fixed connection that cannot be detached (e.g., riveting, welding). Of course, a fixed connection can also be replaced by an integral structure (e.g., manufactured in one piece using a casting process) (except where it is obviously impossible to use an integral molding process).

[0043] In addition, unless otherwise stated, the terms used in any of the technical solutions disclosed in this invention to indicate positional relationships or shapes include states or shapes that are similar to, close to, or approximate with those states or shapes.

[0044] Any component provided by this invention can be assembled from multiple individual components or can be a single component manufactured by a one-piece molding process.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A hollow ES fiber production process, characterized in that: Includes the following steps: (1) Raw material pretreatment and mixing: After drying and preheating the skin layer raw material and the core layer raw material respectively, they are fed into the screw extruder by metering pump in proportion for melt blending; (2) Melt spinning: The melt-blended material is transported to the spinning box and extruded into nascent fibers through a core-sheath composite spinneret. Compressed air with a pressure of 200-300 Pa is introduced into the core channel of the spinneret to form a hollow structure. (3) Gradient cooling and initial stretching: The nascent fibers after molding are subjected to heat preservation treatment and step-by-step slow cooling treatment in sequence, followed by the first stretching, with the first stretching ratio being 1.5-2.5 times; (4) Steam heating and secondary stretching: The fibers that have undergone the first stretching are introduced into the steam box for uniform heating and softening, and then a second stretching is performed. The second stretching ratio is 1.2-1.5 times. (5) Tension setting and oiling: Apply controllable tension to the fibers after secondary stretching for heat setting, and apply spinning oil evenly through an oiling device; (6) Winding: The processed fibers are wound into a filament cake by a winding machine.

2. The hollow ES fiber production process according to claim 1, characterized in that: In step (1), the outer layer material is low-melting-point polyethylene with a melting point of 110-130℃; the core layer material is high-melting-point polyethylene terephthalate with a melting point of 240-260℃; the mass ratio of the outer layer to the core layer is (30:70) to (50:50).

3. The hollow ES fiber production process according to claim 2, characterized in that: In step (1), the core material contains 0.5%-2% inorganic nanofiller and 0.5%-1.5% hydrophilic finishing agent, which are added to the total mass of the core material. The inorganic nanofiller is calcium carbonate powder with a particle size of 20-50 μm.

4. The hollow ES fiber production process according to claim 1, characterized in that: In step (3), heat preservation is performed by a heat preservation device, which includes a liftable box set below the spinneret. The liftable box has several heat preservation hot water chambers inside. The water temperature of the heat preservation hot water chambers decreases from top to bottom. Several threading channels are vertically connected between the heat preservation hot water chambers. The multiple threading channels correspond to multiple spinneret holes on the spinneret. The fiber output from each spinneret hole on the spinneret passes through the threading channel corresponding to its position. The hot water in each heat preservation hot water chamber heats and preserves the fiber through the threading channel.

5. The hollow ES fiber production process according to claim 4, characterized in that: Each insulated hot water chamber is equipped with a heating component, which is electrically connected to a temperature control component to control the temperature of the hot water in the insulated hot water chamber. A cooling water chamber is located directly below several insulated hot water chambers inside the liftable box, and a refrigeration component is installed in the cooling water chamber. Multiple wire threading channels penetrate the cooling water chamber vertically.

6. The hollow ES fiber production process according to claim 4, characterized in that: It also includes a lifting assembly, which includes lifting cylinders symmetrically arranged on the left and right sides of the liftable box. The lifting cylinders are vertically arranged, with the cylinder rods extending downwards and the ends of the cylinders fixed with lifting connecting blocks. The lifting connecting blocks are fixedly connected to the liftable box. The lifting cylinders drive the liftable box to rise and fall through the lifting connecting blocks, so as to achieve contact or separation between the liftable box and the bottom of the spinning box. When the liftable box is separated from the spinning box, it can make way for the horizontal rotation of the rotatable cleaning component.

7. The hollow ES fiber production process according to claim 4, characterized in that: A rotatable cleaning component is provided around the spinning box. The rotatable cleaning component rotates to a position directly below the spinneret and cleans the spinneret. The rotatable cleaning component includes a rotating rod horizontally positioned below the right side of the spinning box. Cleaning brushes are evenly distributed along the length of the top of the rotating rod. The rotating rod is driven to rotate in the horizontal plane by a first rotating motor installed on the right side wall of the spinning box.

8. The hollow ES fiber production process according to claim 7, characterized in that: A first suction hood is horizontally arranged on the right side of the first rotary motor. The bottom of the first suction hood is open and serves as a suction port. The top of the first suction hood is connected to the vacuum cleaner through a first suction pipe. The rotating rod is initially parallel and located directly below the first suction hood. The rotatable cleaning assembly also includes a second suction hood horizontally arranged below the left side of the spinning box. The top of the second suction hood is open and serves as a suction port. The second suction hood is driven to rotate in the horizontal plane by a second rotary motor installed on the left side wall of the spinning box. One end of the second suction hood is connected to a second suction pipe through a rotating connector. The second suction pipe is connected to the vacuum cleaner.

9. The hollow ES fiber production process according to claim 1, characterized in that: In step (3), gradient cooling is achieved using a ring-blowing device. The cooling air temperature gradually decreases from 50-60℃ to 30-40℃ along the fiber conveying direction, and the cooling air velocity is controlled at 0.3-0.8m / s.

10. The hollow ES fiber production process according to claim 1, characterized in that: In step (4), the steam box is equipped with multiple adjustable steam nozzles, the steam temperature is controlled at 105-125℃, and the steam saturation in the box is maintained at 85%-95%.

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