WO2023138310A1

WO2023138310A1 - Wet spinning apparatus and preparation process for sea-island fibers

Info

Publication number: WO2023138310A1
Application number: PCT/CN2022/141916
Authority: WO
Inventors: 刘福娟; 诸葛依娜; 徐岚; 王萍; 张岩
Original assignee: 苏州大学
Priority date: 2022-01-20
Filing date: 2022-12-26
Publication date: 2023-07-27
Also published as: CN114293270B; CN114293270A

Abstract

A wet spinning apparatus for sea-island fibers. The wet spinning apparatus for sea-island fibers comprises: an injection unit (1), comprising a syringe (10) and a needle assembly (11) in communication with the syringe (10); a coagulation unit (2), comprising a coagulation bath (20) connected to the injection unit (1), wherein the coagulation bath (20) is used for the coagulation of a spinning solution; and a collecting unit (3) connected to the coagulation bath (20) and comprising a collecting roller (30) for collecting the sea-island fibers. The syringe (10) comprises a first cavity (101) and a second cavity (102) which are not in communication with each other, a sea-phase spinning solution and an island-phase spinning solution are respectively filled into the first cavity (101) and the second cavity (102), and the needle assembly (11) comprises a first needle (111) in communication with the first cavity (101) and second needles (112) in communication with the second cavity (102), wherein the plurality of second needles (112) are distributed in the first needle (111) at intervals; and the sea-phase spinning solution simultaneously extruded from the first needle (111) and the second needles (112) is wrapped around the plurality of streams of the island-phase spinning solution and is injected into the coagulation bath (20). The sea-island fibers are prepared through a wet spinning method, and the apparatus is simple and reliable in structure and convenient to operate, such that a preparation process is highly safe and is low cost; moreover, a coagulation process of the spinning solutions in the coagulation bath can be stably controlled, and the generated sea-island fibers can be guaranteed to satisfy preparation requirements.

Description

Wet spinning equipment and preparation process for sea-island fibers

technical field

The invention belongs to the technical field of sea-island fiber preparation, and in particular relates to a wet spinning equipment for sea-island fiber, and meanwhile, the invention also relates to a preparation process for sea-island fiber.

Background technique

Sea-island fiber refers to the high polymer of two or more components, which is distributed in the form of sea-islands on the cross-section of the fiber after composite spinning. When the "sea" component is dissolved, the "island" component can emerge from the wrapped "sea" component to obtain a bundled fiber; on the contrary, when the "island" component is dissolved, the remaining "sea" component can form a porous hollow fiber. Sea-island fibers have excellent properties that other ordinary fibers cannot achieve, such as soft fibers, good hygroscopicity, waterproof and breathable, and heat insulation and warmth.

At present, sea-island fibers are mostly prepared by melt spinning, but melt spinning requires high operating temperature and high voltage, the spinning process is cumbersome and complicated, and the preparation cost is high. At the same time, this preparation method requires high standardization of manual operations, and slight negligence can easily cause safety accidents. Therefore, it is necessary to propose a spinning equipment and preparation process that is safe and simple to prepare sea-island fibers.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide an improved wet spinning equipment for sea-island fibers.

At the same time, the invention also provides a preparation process for sea-island fibers.

In order to solve the problems of the technologies described above, the technical scheme that the present invention takes is as follows:

A kind of wet spinning equipment for sea-island fiber, it comprises:

Injection unit comprising syringe, needle assembly;

a coagulation unit comprising a coagulation bath coupled to the end of the needle assembly;

a collecting unit comprising collecting rollers for collecting the coagulated sea-island fibers,

in particular,

The syringe includes a first cavity and a second cavity filled with the marine spinning solution and the island spinning solution respectively. The first cavity and the second cavity are not connected to each other. The needle assembly is inserted into the coagulation bath from the outlet end and includes a first needle and a second needle. The first needle forms a marine spinning solution channel connected to the first cavity. There are multiple second needles distributed in the marine spinning solution channel of the first needle. The connected island phase spinning solution channel, the marine phase spinning solution extruded synchronously from the first needle and the second needle wraps the multiple island phase spinning solution and injects into the coagulation bath.

Preferably, the liquid inlet ends of the first needle and the second needle are located outside the coagulation bath to form an exposed section; the liquid outlet ends of the first needle and the second needle are located in the coagulation bath to form an inner section, wherein the length of the exposed section is shorter than the length of the inner section. In this way, the marine-phase spinning solution can be wrapped around the outer periphery of the second needle in the exposed section, and the wrapping state is maintained after entering the coagulation bath until the island-phase spinning solution is covered by the marine-phase spinning solution from the liquid outlet end to form sea-island fibers.

Preferably, the liquid inlet ends of the first needle and the second needle are arranged flush; the liquid outlet ends of the first needle and the second needle are arranged flush. That is to say, the wrapping is carried out under the premise that the lengths of the two remain equal.

According to a specific implementation and a preferred aspect of the present invention, one of the plurality of second needles is located at the center of the first needle, and the remaining second needles are distributed around the central second needle in order from inside to outside in an annular array. Such a distribution can achieve the best coating effect.

Preferably, the number of the second needles distributed in a circular array sequentially from the inside to the outside increases in an arithmetic sequence. The state of the distribution at this time is the optimal state.

According to yet another specific implementation and preferred aspect of the present invention, the second cavity is located inside the first cavity, and the outlets of the first cavity and the second cavity are flush with each other. That is to say, the marine-phase spinning solution and the island-phase spinning solution are kept wrapped before they enter the needle assembly.

Preferably, both the first cavity and the second cavity are cylindrical, and the first cavity is sleeved outside the second cavity. Such arrangement facilitates the synchronous extrusion of the marine-phase spinning solution and the island-phase spinning solution into the first needle and the second needle.

Further, the first cavity includes a front external cavity and a rear external cavity extending along its own length direction, wherein the inner diameter of the front external cavity is smaller than the inner diameter of the rear external cavity; the second cavity includes a front inner cavity and a rear inner cavity extending along its own length direction, wherein the inner diameter of the front inner cavity is smaller than the inner diameter of the rear inner cavity, and the centerlines of the front inner cavity and the front outer cavity are coincidently arranged. Only such a layout can obtain the required injection thrust, and at the same time, the structure is simple, which is convenient for installation and implementation.

Preferably, the rear end of the anterior inner cavity is located in the anterior external cavity.

According to yet another specific implementation and preferred aspect of the present invention, the syringe further includes a piston movably arranged along the length direction of the cylinder, wherein the piston has a first pushing end matching the first cavity and a second pushing end matching the second cavity, and the first pushing end and the second pushing end can move synchronously to form an injection thrust. Such setting can realize the stable injection of the sea-phase spinning solution and the island-phase spinning solution, which is convenient for controlling the forming of the sea-island fibers and improving the forming quality.

Preferably, the syringe further includes a syringe pump connected to the piston, and the self-propelling part of the syringe pump is respectively docked with the first pushing end and the second pushing end. In this way, the injection is performed with the same force.

Preferably, the first pushing end is ring-shaped, the second pushing end is disc-shaped, and the first pushing end and the second pushing end are aligned. Keeping in sync facilitates injection implementation.

According to yet another specific implementation and preferred aspect of the present invention, the first needles extend horizontally outward from the outlet of the first cavity, and the plurality of second needles extend horizontally outward from the outlet of the second cavity. In this way, the injection thrust direction is consistent with the spinning dope injection direction, which is conducive to stable injection.

Preferably, the liquid inlet ends of the plurality of second needles are sealed and connected to each other from the side walls, and the liquid outlet ends of the plurality of second needles are spaced apart, and the marine spinning solution enters the first cavity and wraps around the periphery of each second needle. This arrangement ensures that the island-phase spinning solution enters each second needle to facilitate the formation of sea-island fibers; at the same time, it can effectively prevent the sea-phase spinning solution from flowing back into the second cavity.

According to yet another specific implementation and preferred aspect of the present invention, the coagulation unit further includes a plurality of tension rollers arranged in the coagulation bath, wherein the plurality of tension rollers are arranged staggered up and down in the height direction of the coagulation bath. Such setting can effectively increase the tension of the sea-island fibers and facilitate collection.

In addition, the collecting unit further includes an air-drying component, wherein the air-drying component is arranged close to the collecting roller and blows airflow toward the collecting roller. Such arrangement enables the fibers to be initially dried, prevents the fibers from being collected from sticking together, and can realize continuous wet preparation of sea-island fibers.

Another technical solution of the present invention: a preparation process for sea-island fibers, which uses the above-mentioned wet spinning equipment, and includes the following steps:

S1, introducing the marine phase spinning solution and the island phase spinning solution into the first cavity and the second cavity correspondingly;

S2. Squeeze the marine-phase spinning solution and the island-phase spinning solution into the coagulation bath synchronously from the first needle and the second needle, so that the marine-phase spinning solution is wrapped around the periphery of the island-phase spinning solution and coagulated in the coagulation bath to form sea-island fibers;

S3. Pulling the formed sea-island fibers to the collection roller and winding them up.

Due to the implementation of the above technical solutions, the present invention has the following advantages compared with the prior art:

The present invention adopts wet spinning to prepare sea-island fibers, and the equipment structure is simple, reliable, and easy to operate. In this way, the preparation process has high safety and low cost; at the same time, it can stably control the coagulation process of the spinning solution in the coagulation bath to ensure that the generated sea-island fibers meet the preparation requirements.

Description of drawings

Fig. 1 is the structural representation of the wet spinning equipment that the present invention is used for sea-island fiber;

Figure 2 is an enlarged schematic view of the needle assembly in Figure 1;

Fig. 3 is the right view diagram of Fig. 2;

Among them: 1. injection unit; 10. syringe; 101. first cavity; 102. second cavity; 103. piston; a1. first pushing end; a2. second pushing end; 104. injection pump; 11. needle assembly; 111. first needle;

2. Coagulation unit; 20. Coagulation bath; 21. Tension roller;

3. Collecting unit; 30. Collecting roller; 31. Air-dried parts.

Detailed ways

In order to make the above-mentioned purpose, features and advantages of the present application more obvious and understandable, the specific implementation manners of the present application will be described in detail below in conjunction with the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the application. However, the present application can be implemented in many other ways different from those described here, and those skilled in the art can make similar improvements without departing from the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" are based on the drawings. The orientation or positional relationship is only for the convenience of describing the present application and simplifying the description, but does not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present application.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

In this application, unless otherwise clearly specified and limited, the terms "installation", "connection", "connection", "fixation" and other terms should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integral body; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly defined. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application according to specific situations.

In the present application, unless otherwise specified and limited, a first feature being "on" or "under" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediary. Moreover, "above", "above" and "above" the first feature on the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature. "Below", "beneath" and "beneath" the first feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is less horizontally than the second feature.

It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or intervening elements may also be present. As used herein, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions are for the purpose of illustration only and are not intended to represent the only embodiments.

As shown in FIG. 1 , the wet spinning equipment for sea-island fibers in this embodiment includes an injection unit 1 , a coagulation unit 2 , and a collection unit 3 .

Specifically, the injection unit 1 includes a syringe 10 and a needle assembly 11 communicating with the syringe 10 .

The syringe 10 includes a first cavity 101 , a second cavity 102 , a piston 103 , and a syringe pump 104 .

Such arrangement has a simple structure and is convenient for installation and implementation.

The second cavity 102 is located inside the first cavity 101 , and the outlets of the first cavity 101 and the second cavity 102 are flush with each other. That is to say, the marine-phase spinning solution and the island-phase spinning solution are kept wrapped before they enter the needle assembly.

Both the first cavity 101 and the second cavity 102 are cylindrical, and the first cavity 101 is sleeved outside the second cavity 102, and the first cavity 101 and the second cavity 102 are not connected to each other, wherein the marine phase spinning liquid and the island phase spinning liquid are respectively filled in the first cavity 101 and the second cavity 102. Such arrangement facilitates the synchronous extrusion of the marine-phase spinning solution and the island-phase spinning solution into the first needle and the second needle.

The first cavity 101 includes an anterior external cavity and a rear external cavity extending along its length direction, wherein the inner diameter of the anterior external cavity is smaller than the internal diameter of the rear external cavity.

The second cavity 102 includes a front inner cavity and a rear inner cavity extending along its length direction, wherein the inner diameter of the front inner cavity is smaller than the inner diameter of the rear inner cavity, and the centerlines of the front inner cavity and the front outer cavity are coincidently arranged. Only such a layout can obtain the required injection thrust, and at the same time, the structure is simple, which is convenient for installation and implementation.

The rear end of the anterior lumen is located in the anterior exocrine. Specifically, the piston 103 is movable along the spinning liquid injection direction, and has a first pushing end a1 attached between the inner wall of the first cavity 101 and the outer wall of the second cavity 102, and a second pushing end a2 attached to the inner wall of the second cavity 102.

The syringe pump 104 is connected to the outer end of the piston 103 and pushes the piston 103 to move along the horizontal direction, wherein the advancing speed of the syringe pump 104 is set at 0-15 mL/h. Such setting can realize the stable injection of the sea-phase spinning solution and the island-phase spinning solution, which is convenient for controlling the forming of the sea-island fibers and improving the forming quality.

As shown in FIG. 2 and FIG. 3 , the needle assembly 11 includes a first needle 111 connected to the first cavity 101 and a second needle 112 connected to the second cavity 102 , wherein there are multiple second needles 112 distributed at intervals inside the first needle 111 , and the marine phase spinning solution extruded synchronously from the first needle 111 and the second needle 112 wraps the multi-strand island phase spinning solution and injects it into the coagulation unit 2 .

Specifically, the first needle 111 extends horizontally outward from the outlet of the first cavity 101, and a plurality of second needles 112 extends horizontally outward from the outlet of the second cavity 102, wherein the liquid inlet ends of the plurality of second needles 112 are sealed and connected to each other from the side wall, and the liquid outlet ends of the plurality of second needles 112 are spaced apart, and the marine spinning solution enters the first cavity 101 and is wrapped around the periphery of each second needle 112. This arrangement ensures that the island-phase spinning solution enters each second needle to facilitate the formation of sea-island fibers; at the same time, it can effectively prevent the sea-phase spinning solution from flowing back into the second cavity.

At the same time, the liquid outlet end of each second needle 112 is aligned with the liquid outlet end of the first needle 111 and inserted into the coagulation unit 2, wherein the diameter of the first needle 111 is d1, where 1mm≤d1≤5mm; the diameter of the second needle 112 is d2, where 0.2mm≤d2≤1mm.

The liquid inlet ends of the first needle 111 and the second needle 112 are arranged flush; the liquid outlet ends of the first needle 111 and the second needle 112 are arranged flush. That is to say, the wrapping is carried out under the premise that the lengths of the two remain equal.

A plurality of second needles 112 are located in the center of the first needle 111 , and the remaining second needles 112 are distributed around the central second needle 112 in order from inside to outside in an annular array. Such a distribution can achieve the best coating effect.

The number of the second needles 112 distributed in a circular array sequentially from the inside to the outside increases in an arithmetic sequence. The state of the distribution at this time is the optimal state.

In this example, there are three annular arrays, the first annular array formed from the inside to the outside has 6 second needles 112, the second annular array has 9 second needles 112, and the second annular array has 12 second needles 112, that is to say, the number of the second needles 112 of the three annular arrays from the inside to the outside increases by 3 every time one annular array goes outward, therefore, it increases in an arithmetic sequence.

In this example, the coagulation unit 2 includes a coagulation bath 20 connected to the injection unit 1, and four tension rollers 21 distributed inside and above the coagulation bath 20, wherein the first needle 111 and the second needle 112 are respectively inserted into the coagulation bath 20 from the liquid outlet.

Specifically, the liquid inlet ends of the first needle head 111 and the second needle head 112 are located outside the coagulation bath 20 to form an exposed section; the liquid outlet ends of the first needle head 111 and the second needle head 112 are located in the coagulation bath 20 to form an inner section, wherein the length of the exposed section is less than the length of the inner section. In this way, the marine-phase spinning solution can be wrapped around the outer periphery of the second needle in the exposed section, and after entering the coagulation bath, the wrapping state is maintained until the island-phase spinning solution is covered by the marine-phase spinning solution from the liquid outlet end to form sea-island fibers.

At the same time, among the four tension rollers 21, two adjacent tension rollers 21 are staggered up and down. Such setting can effectively increase the tension of the sea-island fibers and facilitate collection.

Simultaneously, the speed of four tension rollers 21 increases successively from left to right.

In this example, the collection unit 3 includes a collection roller 30 for collecting sea-island fibers and an air-drying unit 31 .

Specifically, the collecting roller 30 is arranged on the upper right of the coagulation bath 20, and the collecting roller 30 can move left and right. This arrangement facilitates the collection of fibers.

Specifically, there are two air-drying components 31 , and airflows are respectively blown to the sea-island fibers wound on the collecting roller 30 along the vertical direction and the horizontal direction. Such arrangement enables the fibers to be initially dried, prevents the fibers from being collected from sticking together, and can realize continuous wet preparation of sea-island fibers.

In summary, the implementation process of this embodiment is as follows:

S1, introducing the marine phase spinning solution and the island phase spinning solution into the first cavity 101 and the second cavity 102 correspondingly;

S2. Turn on the syringe pump 104. Driven by the syringe pump 104, the piston 103 squeezes the marine-phase spinning solution and the island-phase spinning solution from the first needle 111 and the second needle 112 into the coagulation bath 20 synchronously, so that the marine-phase spinning solution is wrapped around the periphery of the island-phase spinning solution and coagulated in the coagulation bath 20 to form sea-island fibers;

S3. The formed sea-island fibers pass through four tension rollers 21 in turn and are drawn to the collection roller 30 for winding, and while the collection roller 30 is being wound, air-drying components 31 are used to blow dry air to the sea-island fibers from above and one side of the collection roller 30 respectively.

In summary, this implementation has the following advantages:

1. Wet spinning is used to prepare sea-island fibers. The equipment structure is simple, reliable, and easy to operate. In this way, the preparation process has high safety and low cost;

2. It can stably control the coagulation process of the spinning solution in the coagulation bath to ensure that the generated sea-island fibers meet the preparation requirements;

3. The liquid inlet ends of multiple second needles are sealed and connected to ensure that the island-phase spinning solution enters each second needle to facilitate the formation of sea-island fibers; at the same time, it can effectively prevent the sea-phase spinning solution from flowing back into the second cavity;

4. By air-drying the parts, the fibers can be pre-dried to prevent the collection of fibers from sticking together, and the sea-island fibers can be prepared by continuous wet method.

The present invention has been described in detail above, and its purpose is to allow those skilled in the art to understand the content of the present invention and implement it, and can not limit the protection scope of the present invention with this, and all equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

A kind of wet spinning equipment for sea-island fiber, it comprises:

an injection unit, which includes a syringe, and a needle assembly communicating with the syringe;

A coagulation unit comprising a coagulation bath connected to the injection unit, wherein the coagulation bath is used for coagulation of the spinning solution;

a collection unit, which is connected to the coagulation bath and includes a collection roller for collecting sea-island fibers,

It is characterized by:

The syringe includes a first cavity and a second cavity that are not connected to each other, the second cavity is located inside the first cavity, and the outlets of the first cavity and the second cavity are arranged flush, the first cavity and the second cavity are both cylindrical, and the centerline of the first cavity is arranged to coincide with the centerline of the second cavity;

The injector also includes a piston movably arranged along the spinning solution injection direction and an injection pump connected to the piston, wherein the piston has a first pushing end matching the first cavity and a second pushing end matching the second cavity, and the injection pump pushes the piston to move along the spinning solution injection direction;

The marine-phase spinning solution and the island-phase spinning solution are respectively filled in the first cavity and the second cavity. The needle assembly includes a first needle connected to the first cavity and a second needle connected to the second cavity, wherein the first needle extends horizontally from the outlet of the first cavity, and there are multiple second needles. The liquid outlet ends of the needles are aligned and inserted into the coagulation bath, the liquid inlet ends of the plurality of second needles are sealed and connected to each other from the side wall, and the liquid outlet ends of the plurality of second needles are spaced apart, the marine phase spinning solution enters the first cavity and wraps around the periphery of each second needle, and the marine phase spinning solution extruded synchronously from the first needles and the second needles wraps multiple strands of the island phase spinning solution and injects them into the coagulation bath;

The coagulation unit also includes a plurality of tension rollers arranged in the coagulation bath, wherein two adjacent tension rollers are staggered up and down; the collection unit also includes air-drying components, wherein the air-drying components are arranged close to the collection rollers and blow airflow toward the collection rollers.
A kind of wet spinning equipment for sea-island fiber, it comprises:

Injection unit comprising syringe, needle assembly;

a coagulation unit comprising a coagulation bath coupled to the end of the needle assembly;

a collecting unit comprising collecting rollers for collecting the coagulated sea-island fibers,

It is characterized by:

The syringe includes a first cavity and a second cavity respectively filled with the marine spinning solution and the island spinning solution, the first cavity and the second cavity are not connected to each other, the needle assembly is inserted into the coagulation bath from the liquid outlet end, and includes a first needle and a second needle, wherein a marine spinning solution channel communicating with the first cavity is formed inside the first needle, and there are multiple second needles distributed in the marine spinning solution channel of the first needle. The island-phase spinning solution channels communicated with each other, and the marine-phase spinning solution extruded synchronously from the first needle and the second needle wraps multiple island-phase spinning solutions and injects them into the coagulation bath.
The wet spinning equipment for sea-island fibers according to claim 2, characterized in that: the liquid inlet ends of the first needle and the second needle are located outside the coagulation bath to form an exposed section; the liquid outlet ends of the first needle and the second needle are located in the coagulation bath to form an inner section, wherein the length of the exposed section is shorter than the length of the inner insertion section.
The wet spinning equipment for sea-island fibers according to claim 3, characterized in that: the liquid inlet ends of the first needle and the second needle are arranged flush; the liquid outlet ends of the first needle and the second needle are arranged flush.
The wet spinning equipment for sea-island fibers according to claim 3, characterized in that one of the plurality of second needles is located at the center of the first needle, and the remaining second needles are distributed in a circular array around the center from inside to outside.
The wet spinning equipment for sea-island fibers according to claim 5, characterized in that: the number of the second needles distributed in a circular array sequentially from the inside to the outside increases in an arithmetic sequence.
The wet spinning equipment for sea-island fibers according to claim 2, characterized in that: the second cavity is located inside the first cavity, and outlets of the first cavity and the second cavity are flush with each other.
The wet spinning equipment for sea-island fibers according to claim 7, characterized in that: the first cavity and the second cavity are both cylindrical, and the first cavity is sleeved outside the second cavity.
The wet spinning equipment for sea-island fibers according to claim 8, characterized in that: the first cavity includes a front outer cavity and a rear outer cavity extending along its own length direction, wherein the inner diameter of the front outer cavity is smaller than the inner diameter of the rear outer cavity; the second cavity includes a front inner cavity and a rear inner cavity extending along the length direction of itself, wherein the inner diameter of the front inner cavity is smaller than the inner diameter of the rear inner cavity, and the centerlines of the front inner cavity and the front outer cavity are coincident.
The wet spinning equipment for sea-island fibers according to claim 9, characterized in that: the rear end of the front inner cavity is located in the front outer cavity.
The wet spinning equipment for sea-island fibers according to claim 8, wherein the injector further comprises a piston movably arranged along the length direction of the cylinder, wherein the piston has a first pushing end matching the first cavity and a second pushing end matching the second cavity, and the first pushing end and the second pushing end can move synchronously to form an injection thrust.
The wet spinning equipment for sea-island fibers according to claim 11, characterized in that: the syringe further comprises a syringe pump connected to the piston, and the syringe pump is respectively docked with the first pushing end and the second pushing end from a pushing part.
The wet spinning equipment for sea-island fibers according to claim 11, wherein the first pushing end is ring-shaped, the second pushing end is disc-shaped, and the first pushing end and the second pushing end are aligned.
The wet spinning equipment for sea-island fibers according to claim 2, wherein the first needles extend horizontally outward from the outlet of the first cavity, and the plurality of second needles extend horizontally outward from the outlet of the second cavity. 15. The wet spinning equipment for sea-island fibers according to claim 14, characterized in that: the liquid inlet ends of the plurality of second needles are sealed and connected to each other from the side wall, and the liquid outlet ends of the plurality of second needles are spaced apart, and the marine phase spinning solution enters the first cavity and is wrapped around the periphery of each of the second needles.
The wet spinning equipment for sea-island fibers according to claim 2, wherein the coagulation unit further comprises a plurality of tension rollers arranged in the coagulation bath, wherein the plurality of tension rollers are arranged staggered up and down in the height direction of the coagulation bath.
The wet spinning equipment for sea-island fibers according to claim 2, wherein the collection unit further includes an air drying unit, wherein the air drying unit is arranged close to the collection roller and blows air toward the collection roller.
A preparation process for sea-island fibers, characterized in that it adopts the wet spinning equipment for sea-island fibers according to any one of claims 1 to 17, and comprises the following steps:

S1, introducing the marine phase spinning solution and the island phase spinning solution into the first cavity and the second cavity correspondingly;

S2. Squeeze the marine-phase spinning solution and the island-phase spinning solution into the coagulation bath synchronously from the first needle and the second needle, so that the marine-phase spinning solution is wrapped around the periphery of the island-phase spinning solution and coagulated in the coagulation bath to form sea-island fibers;

S3. Pulling the formed sea-island fibers to the collection roller and winding them up.