CN115787117A - Fiber width automatic control device and preparation method of polyacrylonitrile precursor - Google Patents

Abstract

The invention relates to a fiber width automatic control device and a preparation method of polyacrylonitrile precursor. The automatic control device for the fiber width comprises a transverse member, a fiber width adjusting structure and an automatic control system. The fiber width adjusting structure comprises a first moving part and a second moving part which are oppositely arranged; one end of the first moving part and one end of the second moving part are respectively connected with the transverse part in a sliding manner; the width of the fiber tows is limited through the distance between the first moving piece and the second moving piece; the automatic control system comprises an automatic driving control mechanism and a transmission structure. The automatic drive control mechanism is in drive connection with the transmission structure, and the transmission structure is connected with the first moving piece and the second moving piece and used for driving the first moving piece and the second moving piece to transversely slide on the transverse piece. The invention is used for automatically and quantitatively controlling the spreading of the fiber tows, improving the performance uniformity and stability of the precursor in batches, reducing broken filaments and reducing the probability of roller winding.

Description

Fiber width automatic control device and preparation method of polyacrylonitrile precursor

Technical Field

The invention relates to the technical field of carbon fibers, in particular to a fiber width automatic control device and a preparation method of polyacrylonitrile precursor.

Background

Carbon fiber is a high-strength and high-modulus emerging fiber material. The high-strength high-modulus high-temperature-resistant composite material has a plurality of excellent performances such as high strength, high modulus, small thermal expansion coefficient, low density, low resistance, fatigue resistance, high temperature resistance and the like, and is widely used in military and civil materials. The polyacrylonitrile has good production stability, occupies a leading position in various carbon fibers, and has wide market prospect. The market demand drives the technical innovation, and a plurality of domestic polyacrylonitrile carbon fiber companies begin to research and develop independently and enter the hard period of intense market competition.

At present, the domestic carbon fiber mainly has the problems of unstable performance, large dispersion coefficient, broken filaments and the like, and large deviation in appearance, wherein the instability of the production quality of precursor is one of the key factors. In the production process of the protofilament, the procedures of solidification forming, water washing, oiling, drying and the like in a medium are generally needed. When the solidified and formed filament bundles are subjected to these steps, it is inevitable that the filament bundles are unevenly scattered, stacked and unevenly spread. In terms of each step: in the coagulation bath, the filament bundle is nonuniform in width, which means that the degree of double diffusion of the filament bundle in the coagulation bath is inconsistent, and the morphological structure of nascent fibers is easily inconsistent; in water washing, the uneven width leads to poor water washing effect of individual tows, further leads to solvent residue, finally leads to more surface defects of the tows, and even leads to hot melting phenomenon during subsequent oxidation and carbonization; when oiling, the oiling effect can be influenced; during steam drafting, uneven drafting is easy to occur, the yarn breakage rate is high, and finally the yield of precursor and carbon fiber is low and the performance is poor.

In the prior art, the width of the fiber tows is manually and mechanically controlled, and referring to the fiber width adjusting device shown in fig. 4 and 5, when the width of the fiber tows is adjusted, screws are manually screwed to adjust the width (referring to the screws 6 in fig. 4 and the screws 5 in fig. 5). However, the inventors of the present invention have found that the prior art has at least the following technical problems:

(1) The adjustment is manually carried out, the temperature of the coagulation bath where a solvent (such as dimethyl sulfoxide) exists and the hot drawing is higher, so that potential safety hazards exist when the width is manually adjusted.

(2) During manual adjustment, the screw is unscrewed manually, then the fiber width adjusting device slides on the cross rod to a set position, and then the screw is tightened. If the number of running tows is large, the space between the spinning positions is too small, and during the operation, the operation is easy to miss, and the tows are placed in positions which are not the spinning channel, so that the tows are stringed and wound.

(3) The single spinning position and different adjacent spinning positions have no uniform standard, the distance is measured by naked eyes and then adjusted, so that the problem of non-uniform width exists, the width is not uniform in the whole operation process from coagulating bath to water washing to hot drawing to oiling, the produced product is not uniform, and the quality is not stable.

(4) If there is any abnormality in the production process, the adjustment is wanted, and if there are a plurality of spinning positions, the middle spinning position can not be reached by the manual work, and the adjustment can not be carried out at all.

Therefore, the fiber width adjusting device in the prior art is inconvenient for a production line for rapid production, and is easy to confuse a yarn path during operation, so that the probability of winding the roller is greatly increased, and the safety risk to operators is high.

Disclosure of Invention

In view of the above, the invention provides an automatic control device for fiber width and a preparation method of polyacrylonitrile precursor, and mainly aims to automatically control the width of a fiber tow.

In order to achieve the purpose, the invention mainly provides the following technical scheme:

in one aspect, an embodiment of the present invention provides an automatic control device for a fiber width, including:

a cross member;

the fiber width adjusting structure comprises a first moving piece and a second moving piece which are oppositely arranged; one end of the first moving part and one end of the second moving part are respectively connected with the transverse part in a sliding manner; the width of the fiber tows is limited through the distance between the first moving piece and the second moving piece;

the automatic control system comprises an automatic driving control mechanism and a transmission structure; the automatic driving control mechanism is in driving connection with a transmission structure, and the transmission structure is connected with the first moving piece and the second moving piece and used for driving the first moving piece and the second moving piece to transversely slide on the transverse piece;

the automatic driving control mechanism drives the transmission structure to move, so that the first moving piece and the second moving piece are driven to transversely slide on the transverse piece, and the distance between the first moving piece and the second moving piece is adjusted to automatically control the width of the fiber tows.

Preferably, the automated drive control mechanism includes:

an automatic distributor of gas source;

the diaphragm divides the cavity into a first closed cavity and a second closed cavity; an elastic piece is arranged on the inner wall of the cavity of the second cavity and connected with the diaphragm; the diaphragm is an elastic body and can deform under the action of force, so that a stressed part of the diaphragm moves towards a first direction or a direction opposite to the first direction; when the stressed part of the diaphragm moves towards the first direction under the action of force, the diaphragm compresses the elastic part;

one end of the air inlet pipeline is connected with the automatic air source distributor, and the other end of the air inlet pipeline is connected with the first cavity; the automatic gas source distributor is used for introducing distributed compressed gas with set pressure into the first cavity through a gas inlet pipeline and pushing the force-bearing part of the diaphragm to move towards a first direction;

one end of the driving rod is positioned in the first cavity and connected with the diaphragm, and the other end of the driving rod is positioned outside the cavity and connected with the transmission structure in a driving way; wherein the driving rod moves along a first direction or a direction opposite to the first direction along with the force-bearing part of the diaphragm;

preferably, the elastic member is a spring;

preferably, the membrane comprises an edge part and a force-bearing part; wherein the edge portion is connected with the inner wall of the cavity; the driving rod and the elastic piece are connected with the stress part of the diaphragm.

Preferably, the automatic driving control mechanism further comprises a feedback air pipe; one end of the feedback air pipe is communicated with the first cavity, and the other end of the feedback air pipe is connected with the automatic air source distributor and used for feeding back the pressure of the compressed air in the first cavity to the automatic air source distributor.

Preferably, the transmission structure includes:

a longitudinal slide rail;

a slider disposed in the longitudinal slide; the automatic driving control mechanism is in driving connection with the sliding block and is used for driving the sliding block to longitudinally move in the longitudinal sliding rail;

a first movable bar having a first end and a second end disposed opposite to each other; the first end of the first movable rod is connected with the sliding block, and the second end of the first movable rod is connected with the first moving piece;

a second movable bar having a first end and a second end disposed opposite; the first end of the second movable rod is connected with the sliding block, and the second end of the second movable rod is connected with the second moving piece;

when the automatic driving control mechanism drives the sliding block to longitudinally move in the longitudinal sliding rail, the first movable rod and the second movable rod which are connected with the sliding block drive the first moving piece and the second moving piece to transversely move on the transverse piece.

Preferably, when the sliding block slides to the lowest end of the longitudinal sliding rail, the included angle between the first movable rod and the longitudinal sliding rail and the included angle between the second movable rod and the longitudinal sliding rail are greater than 45 degrees; and/or when the sliding block slides to the uppermost end of the longitudinal sliding rail; the included angle between the first movable rod and the longitudinal slide rail and the included angle between the second movable rod and the longitudinal slide rail are more than or equal to 15 degrees and less than 45 degrees; and/or the length of the longitudinal slide rail ensures that the distance between the first moving part and the second moving part does not exceed 15cm.

Preferably, the first moving member includes a first moving rod and a first sliding structure; one end of the first moving rod is connected with the transverse piece in a sliding mode through a first sliding structure; the first movable rod is connected with the first sliding structure.

Preferably, the second moving member includes a second moving rod and a second sliding structure; one end of the second moving rod is connected with the transverse piece in a sliding mode through a second sliding structure; the second movable rod is connected with the second sliding structure.

Preferably, the cross member is a cross bar.

Preferably, the number of the fiber width adjusting structures is at least one; the number of the automatic control systems is consistent with that of the fiber width adjusting structures, and the automatic control systems are in one-to-one corresponding driving connection. Preferably, when the fiber width adjusting structure is a plurality of fiber width adjusting structures, the plurality of fiber width adjusting structures are connected to the transverse member in a sliding mode.

On the other hand, the embodiment of the invention provides a preparation method of polyacrylonitrile precursor, wherein in the preparation of the polyacrylonitrile precursor: the automatic control device for the fiber width is used for automatically and quantitatively controlling the width of the fiber tows in any one or more of the processes of solidification forming, washing and oiling.

Preferably, in any one of the solidification forming process, the water washing process and the oiling process, the step of automatically and quantitatively controlling the width of the fiber tows comprises the following steps:

controlling a first moving member and a second moving member in the fiber width automatic control device corresponding to each spinning position to transversely slide on the transverse member and move to a preset position so that the first moving member and the second moving member are positioned at two sides of a running fiber tow corresponding to the spinning position;

in the running process of the fiber tows, the air source pressure of the air source automatic distributor is adjusted, so that the first moving piece and the second moving piece of the first spinning position control the width of the fiber tows to a set width, and the air source pressure value at the moment is recorded as a standard set value;

and setting the air source pressures corresponding to other spinning positions to the standard set value so as to control the width of the fiber tows of other spinning positions to the set width.

Compared with the prior art, the fiber width automatic control device and the preparation method of the polyacrylonitrile precursor have at least the following beneficial effects:

on one hand, the automatic control device for the fiber width provided by the embodiment of the invention designs the transverse member, the fiber width adjusting structure and the automatic control system; when controlling the width of operation fibre silk bundle, only need place first moving member, second moving member in the both sides of operation fibre silk bundle, then slide on the horizontal piece through first moving member of automated control system control, second moving member to adjust the distance of first moving member, second moving member, control the width of operation fibre silk bundle into required width. Therefore, the fiber width automatic control device provided by the embodiment can be realized only by operating the automatic drive control mechanism (for example, the automatic drive control mechanism is provided with an adjusting button), manual mechanical control is not needed, the problem that the prior art is easy to confuse yarn channels due to manual control during operation, the probability of winding the roller is greatly increased, and the safety risk of operators is high can be avoided, so that the performance uniformity and stability of the raw yarns in batches can be improved, the discrete degree is reduced, the broken filaments are reduced, and the probability of winding the roller is reduced.

Further, according to the automatic control device for the fiber width provided by the embodiment of the invention, the automatic drive control mechanism is designed into an automatic air source distributor, a cavity, an air inlet pipeline and a drive rod; the pressure of compressed gas input into the first cavity in the cavity is controlled through the gas source distributor, the diaphragm is controlled to deform and deform, the driving rod drives the transmission structure to drive the first moving piece and the second moving piece to slide and slide at the transverse piece, the distance between the first moving piece and the second moving piece is controlled, and the automatic quantitative control of the width of the running fiber tows is achieved. The automatic driving control mechanism is simple in design concept, easy to implement and capable of well performing automatic quantitative control on the width of the fiber tows.

On the other hand, the embodiment of the invention provides a preparation method of polyacrylonitrile protofilament, which comprises the following steps: any one or more of the solidification forming process, the water washing process and the oiling process adopts the automatic control device for the fiber width to automatically and quantitatively control the width of the fiber tows, so that the uniformity and the stability of the performance of the raw filaments in batches are improved, the dispersion degree is reduced, broken filaments are reduced, and the probability of winding rollers is reduced.

In summary, the fiber width automatic control device and the preparation method of the polyacrylonitrile precursor provided by the embodiment of the invention can quantitatively and automatically control the width of the precursor, are suitable for controlling the width of the precursor in each process (coagulating bath, washing and oiling) of wet spinning and dry-jet wet spinning precursor production, and mass production data show that the invention can reduce the content of the sulfoxide in the fiber tows in the washing process, improve the uniformity of the oiling rate of the tows in the oiling process and the like, avoid the floating of monofilaments on the production stability, reduce the condition of roller winding caused by filaments, improve the production capacity and ensure the production stability.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.

Drawings

Fig. 1 is a schematic structural diagram of an automatic control device for fiber width according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a drive configuration and a fiber width adjustment configuration provided by an embodiment of the present invention;

FIG. 3 is a schematic diagram of the configuration of the automated drive control mechanism;

FIG. 4 is a schematic view of a prior art fiber width adjusting device;

fig. 5 is a schematic view of a prior art fiber width adjusting device.

Detailed Description

To further explain the technical means and effects of the present invention adopted to achieve the predetermined object, the following detailed description of the embodiments, structures, features and effects according to the present invention will be made with reference to the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "an embodiment" refers to not necessarily the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Example 1

The present embodiment provides an automatic control device for fiber width, as shown in fig. 1-3, which includes a cross member 1, a fiber width adjusting structure 2, and an automatic control system. The fiber width adjusting structure 2 includes a first moving member 21 and a second moving member 22 arranged oppositely (the first moving member 21 and the second moving member 22 are parallel). One end (upper end) of the first moving member 21 and one end (upper end) of the second moving member 22 are respectively connected with the transverse member 1 in a sliding manner; wherein, the width of the fiber tows is limited by the distance between the first moving member 21 and the second moving member 22. The automatic control system comprises an automatic driving control mechanism 3 and a transmission structure 4; the automatic driving control mechanism 3 is in driving connection with the transmission structure 4, and the transmission structure 4 is connected with the first moving part 21 and the second moving part 22 and used for driving the first moving part 21 and the second moving part 22 to transversely slide on the transverse member 1. The automatic control device comprises a transverse member 1, a transmission structure 4, an automatic drive control mechanism 3, a first moving member 21, a second moving member 22 and a second moving member 22, wherein the transmission structure 4 is driven to move through the automatic drive control mechanism 3, so that the first moving member 21 and the second moving member 22 are driven to transversely slide on the transverse member 1, and the width of a fiber tow is automatically controlled by adjusting the distance between the first moving member 21 and the second moving member 22.

The automatic control device for the fiber width provided by the embodiment is characterized in that a transverse member 1, a fiber width adjusting structure 2 and an automatic control system are designed; when the width of the fiber tows is controlled to run, the first moving piece 21 and the second moving piece 22 are placed on two sides of the fiber tows to run, then the transmission structure 4 is driven by the automatic driving control mechanism 3 to drive the first moving piece 21 and the second moving piece 22 to slide on the transverse piece 1, so that the distance between the first moving piece 21 and the second moving piece 22 is adjusted, and the width of the fiber tows to run is controlled to be the required width. Therefore, the automatic control device for the fiber width provided by the embodiment can be realized only by operating the automatic drive control mechanism (for example, controlling a button on the automatic drive control mechanism), the manual mechanical control is not needed, the problem that the prior art is easy to confuse a yarn channel due to manual control during operation, the probability of winding a roller is greatly increased, and the safety risk of an operator is high can be avoided, so that the performance uniformity and the stability of the raw yarns in batches can be improved, the discrete degree is reduced, the broken yarns are reduced, and the probability of winding the roller is reduced.

Example 2

Preferably, compared with embodiment 1, as shown in fig. 1 to 3, the present embodiment further designs the automatic driving control mechanism 3 as follows:

the automatic drive control mechanism of the embodiment comprises an automatic air source distributor 31, a cavity, an air inlet pipeline 32 and a drive rod 38. Wherein, a diaphragm 33 is arranged in the cavity, and the diaphragm 33 divides the cavity into a first cavity 37 and a second cavity 36 which are closed; an elastic piece 34 is arranged on the inner wall of the second cavity 36, and the elastic piece 34 is connected with the diaphragm 33; wherein, the diaphragm 33 is connected with the inner wall of the cavity, the diaphragm 33 is an elastic body (such as rubber material) and can deform under the action of force, so that the stressed part of the diaphragm 33 moves towards the first direction or the direction opposite to the first direction; wherein, when the force-receiving part of the diaphragm 33 moves to the first direction by a force, the diaphragm 33 compresses the elastic member 34. One end of the air inlet pipeline 32 is connected with the automatic air source distributor 31, and the other end is connected with the first cavity 37; the automatic gas source distributor 31 is configured to introduce the distributed compressed gas with a set pressure into the first cavity 37 through the gas inlet line 32, wherein the diaphragm 33 slides in the first direction under the pressure of the compressed gas. One end of the driving rod 38 is located in the first cavity 37 and connected to the diaphragm 33, and the other end is located outside the cavity and drivingly connected to the transmission structure 4. Wherein the driving rod 38 moves along the first direction or the direction opposite to the first direction along with the force-receiving portion of the diaphragm 33. The elastic member 34 is a spring. Preferably, the membrane 33 comprises an edge portion and a force-bearing portion; wherein the edge portion is connected with the inner wall of the cavity; the driving rod 38 and the elastic element 34 are connected with the stressed part of the diaphragm. In addition, an extension part is arranged between the edge part and the force bearing part. When force in the first direction is applied to the force-bearing part, the extension part can extend towards the first direction, and the length of the extension part is different along with the difference of the force.

Here, in the fiber width automatic control device provided in this embodiment, the automatic drive control mechanism is designed as the automatic air source distributor 31, the cavity, the air inlet pipeline 32 and the drive rod 38; the pressure of compressed gas input into the first cavity in the cavity is controlled through the air source distributor 31, and then the deformation and the deformation degree of the diaphragm 33 (the deformation degree here refers to the movement distance of the stressed part of the diaphragm) are controlled, and then the driving structure 4 is driven through the driving rod 38 to drive the first moving part 21 and the second moving part 22 to slide and slide at the transverse part, so that the control of the distance between the first moving part 21 and the second moving part 22 is realized, and further the automatic quantitative control of the width of the running fiber tows is realized.

Preferably, the elastic member 34 is a spring.

Preferably, the automatic driving control mechanism 3 further comprises a feedback air pipe 35; one end of the feedback air pipe 35 is communicated with the first cavity 37, and the other end is connected to the automatic air source distributor 31, and is configured to feed back the pressure of the compressed air in the first cavity 37 to the automatic air source distributor 31 (a pressure sensor is present in the automatic air source distributor 31, and is adjusted according to the pressure condition).

Example 3

Preferably, the present embodiment provides an automatic control device for fiber width, compared to the above embodiments, as shown in fig. 1 to 3, the present embodiment further designs the transmission structure 4 as follows:

the transmission structure 4 comprises a longitudinal slide rail 42, a slide block 41, a first movable rod 43 and a second movable rod 44. Wherein the slide 41 is arranged in the longitudinal slide 42; the automatic drive control mechanism 3 is in driving connection with the slider 41 (specifically, the driving rod 38 is in driving connection with the slider 41) for driving the slider 41 to move longitudinally in the longitudinal sliding rail 42. The first movable bar 43 has a first end and a second end disposed oppositely; wherein, the first end of the first movable rod 43 is connected with the slide block 41, and the second end is connected with the first moving member 21. The second movable bar 44 has a first end and a second end disposed opposite to each other; wherein, the first end of the second movable rod 44 is connected with the sliding block 41, and the second end is connected with the second moving part 22. When the automatic drive control mechanism 3 drives the sliding block 41 to move longitudinally in the longitudinal sliding rail 42, the first movable rod 43 and the second movable rod 44 connected with the sliding block 41 drive the first movable member 21 and the second movable member 22 to move transversely on the transverse member 1 (here, a connecting line between the sliding block 41, the second end of the first movable rod 43 and the second end of the second movable rod 44 is approximately triangular, specifically, when the sliding block 41 moves upwards, the first movable member 21 and the second movable member 22 move along the transverse member 1 in a direction of approaching each other, and when the sliding block 41 moves downwards, the first movable member 21 and the second movable member 22 move along the transverse member 1 in a direction of departing from each other).

Here, the fiber width automated control device that this embodiment provided, through setting transmission structure 4 to above-mentioned structure, simple structure, design benefit, be convenient for implement, stability is good.

Preferably, when the sliding block 41 slides to the lowest end of the longitudinal sliding rail 42, the included angle between the first movable rod 43 and the second movable rod 44 and the longitudinal sliding rail 42 is greater than 45 degrees, so as to improve the stability (if the included angle is too large, the component force of the sliding block movement is smaller; and in addition, the width of each spinning position and the adjacent spinning positions is limited). When the slider 41 slides to the uppermost end of the longitudinal slide rail 42; the included angles between the first movable rod 43 and the longitudinal slide rail 42 and between the second movable rod 44 and the longitudinal slide rail 42 are greater than or equal to 15 degrees and smaller than 45 degrees, so that the stability is improved. The length of the longitudinal slide 42 ensures that the distance between the first moving part 21 and the second moving part 22 does not exceed 15cm.

Example 4

Preferably, the present embodiment provides an automatic control device for fiber width, compared to the above embodiments, as shown in fig. 1 to 3, the present embodiment further performs the following design:

the first moving member 21 includes a first moving bar 211 and a first sliding structure 212; wherein, one end of the first moving rod 211 is slidably connected with the cross member 1 through a first sliding structure 212; the first sliding structure 212 is connected to the first movable bar 43. The second moving member 22 includes a second moving rod 221 and a second sliding structure 222; wherein, one end of the second moving rod 221 is slidably connected with the cross member 1 through the second sliding structure 222; the second sliding structure 222 is connected to the second movable bar 44. The cross-member 1 is a cross-bar.

Preferably, the above embodiment provides an automatic control device for fiber width, as shown in fig. 1, the number of the fiber width adjusting structures 2 is at least one, and is the same as the number of the produced yarns; the number of the automatic control systems is consistent with that of the fiber width adjusting structures 2, and the automatic control systems are in one-to-one corresponding driving connection. Preferably, when the fiber width adjusting structure is plural, the plural fiber width adjusting structures 2 are slidably connected to the cross member 1.

Preferably, the automation control system of the above embodiments can be integrated in one housing.

Preferably, the automatic gas source distributor is provided with a pressure regulating structure, and the pressure of the compressed gas introduced into the first cavity (gas source pressure) can be regulated by the pressure regulating structure, and the pressure value can be read out, and the pressure value is called as a gas source pressure value.

Preferably, the first moving bar 211, the second moving bar 221, the first moving bar 43, and the second moving bar 44 in the above embodiments are made of stainless steel and the surfaces thereof are polished, the elastic member 34 and the driving bar 38 are also made of stainless steel, the diameter of the first moving bar 211 and the second moving bar 221 is 1-1.5cm, and the length thereof can be set according to the requirement of the production process.

Example 5

Preferably, this embodiment provides a method for preparing polyacrylonitrile precursor, wherein, in the preparation of polyacrylonitrile precursor: the automatic control device for the fiber width of the embodiment is adopted to automatically and quantitatively control the width of the fiber tows in any one or more of the solidification forming process, the water washing process and the oiling process.

Preferably, in any one of the solidification forming process, the water washing process and the oiling process, the step of automatically and quantitatively controlling the width of the fiber tows comprises the following steps:

and controlling the first moving piece and the second moving piece in the fiber width automatic control device corresponding to each spinning position to transversely slide on the transverse piece and move to a preset position, so that the first moving piece and the second moving piece are positioned at two sides of the running fiber tows corresponding to the spinning positions.

In the running process of the fiber tows, the air source pressure of the air source automatic distributor is adjusted, so that the first moving piece and the second moving piece of the first spinning position control the width of the fiber tows to a set width, and the air source pressure value at the moment is recorded as a standard set value;

and setting the air source pressures corresponding to other spinning positions to the standard set values so as to control the widths of the fiber tows of other spinning positions to the set widths.

For example, in the coagulation molding step, a plurality of spinning positions are provided, and the plurality of spinning positions are all fiber tows of the same specification. When the automatic fiber width control device of the above embodiment is used in a coagulation bath, as shown in fig. 1 to 3, the gas transmission pressure of the automatic gas source distributor 31 is adjusted, the first moving rod 211 and the second moving rod 221 in the automatic fiber width control device corresponding to each spinning position are moved to the preset positions and positioned at both sides of the fiber bundle corresponding to the spinning position, and when the fiber bundle is moved, the gas transmission pressure of the automatic gas source distributor 31 is adjusted to a fixed width corresponding to one of the spinning positions (e.g., the outermost spinning position for easy observation), and then the set pressure value is recorded as a standard set value. Then, the air delivery pressure of the automatic air source adjusting distributor 31 corresponding to other spinning positions is set to the standard set value; so as to control the width of the fiber tows of other spinning positions to be fixed width. The same method as described above is also used in other steps.

The invention is further illustrated by the following specific experimental examples:

experimental example 1

The experimental example adopts dry-jet wet spinning to prepare polyacrylonitrile protofilament, and specifically comprises the following steps:

as shown in fig. 1 to 3, the fiber width automatic control device provided in the above embodiment was used in a coagulation bath (coagulation molding step) and a rinsing bath (rinsing step). Wherein the content of the first and second substances,

in the coagulation forming process, when the fiber bundle is used for the first time, as shown in fig. 1 to 3, the air delivery pressure of the automatic air source distributor 31 is adjusted, the first moving rod 211 and the second moving rod 221 in the automatic fiber width control device corresponding to each spinning position are moved to preset positions so as to be positioned at both sides of the running fiber bundle corresponding to the spinning position, and when the fiber bundle is running, the air delivery pressure of the automatic air source distributor 31 corresponding to one spinning position (for example, the spinning position at the outermost side is convenient to observe) is further adjusted to control the fiber bundle to a fixed width, and then the set pressure value is recorded as a standard set value. Then, the air delivery pressures of the automatic air source adjusting distributors 31 corresponding to the other spinning positions are all set to the standard set values, so that the widths of the fiber tows of the other spinning positions are all controlled to be fixed.

In the water washing process, when the fiber width automatic control device is used for the first time, as shown in fig. 1 to 3, the air delivery pressure of the air source automatic distributor 31 is adjusted, the first moving rod 211 and the second moving rod 221 in the fiber width automatic control device corresponding to each spinning position are moved to preset positions, the first moving rod and the second moving rod are positioned at two sides of the running fiber tows corresponding to the spinning positions, when the fiber tows run, the air delivery pressure of the air source automatic distributor 31 is adjusted to be corresponding to one of the spinning positions (for example, the spinning position at the outermost side is convenient to observe) to control the fiber tows to be in a fixed width, and then the set pressure value is recorded as a standard set value. Then, the air delivery pressures of the automatic air source adjusting distributors 31 corresponding to the other spinning positions are all set to the standard set values so as to control the widths of the fiber tows of the other spinning positions to be constant.

After the automatic control device for the fiber width is installed, drawing times are applied by the drawing rollers, the running tows are located in the center of the filament moving groove, and the finished filaments are obtained through procedures of washing, hot drawing, oiling, steaming and drawing and the like.

In the operation process of the fiber tows in the experimental embodiment, the conditions of monofilament floating and filament overlapping are obviously reduced, the bundled nascent fibers stably operate, the number of broken filaments is greatly reduced, the phenomenon of roller winding of a pulling-out roller is also obviously reduced, and the performance of the spun yarns at the spinning position is tested, as shown in table 1.

Experimental example 2

In the experimental example, the polyacrylonitrile precursor is prepared by wet spinning, which specifically comprises the following steps:

as shown in fig. 1 to 3, the fiber width automatic control device provided in the above embodiment was used for a coagulation bath and a rinsing bath.

In the coagulation forming process, when the fiber bundle is used for the first time, as shown in fig. 1 to 3, the air delivery pressure of the automatic air source distributor 31 is adjusted, the first moving rod 211 and the second moving rod 221 in the automatic fiber width control device corresponding to each spinning position are moved to preset positions so as to be positioned at both sides of the running fiber bundle corresponding to the spinning position, and when the fiber bundle is running, the air delivery pressure of the automatic air source distributor 31 corresponding to one spinning position (for example, the spinning position at the outermost side is convenient to observe) is further adjusted to control the fiber bundle to a fixed width, and then the set pressure value is recorded as a standard set value. Then, the air delivery pressures of the automatic air source adjusting distributors 31 corresponding to the other spinning positions are all set to the standard set values, so that the widths of the fiber tows of the other spinning positions are all controlled to be fixed.

In the water washing process, when the fiber width automatic control device is used for the first time, as shown in fig. 1 to 3, the air delivery pressure of the air source automatic distributor 31 is adjusted, the first moving rod 211 and the second moving rod 221 in the fiber width automatic control device corresponding to each spinning position are moved to the preset positions, so that the first moving rod and the second moving rod are located at two sides of the running fiber tows corresponding to the spinning positions, when the fiber tows run, the air delivery pressure of the air source automatic distributor 31 is adjusted to be corresponding to one of the spinning positions (for example, the spinning position located at the outermost side is convenient to observe) to control the fiber tows to a fixed width, and then the set pressure value is recorded as a standard set value. Then, the air delivery pressures of the automatic air source adjusting distributors 31 corresponding to the other spinning positions are all set to the standard set values, so that the widths of the fiber tows of the other spinning positions are all controlled to be fixed.

After the automatic control device for the fiber width is installed, the running tows are located in the center of the filament running groove and vertically penetrate through the first moving rod and the second moving rod, and other procedures keep the same technological parameters.

In the operation process of the fiber tows in the experimental embodiment, the uniform and stable width of the tows can be obviously seen, no yarn hanging phenomenon exists in adjacent spinning positions, compared with the spinning positions without the device, the number of the broken filaments is greatly reduced, the roller winding phenomenon is also obviously reduced, and the performance of the original yarns at the spinning positions is tested, as shown in table 1.

Comparative example 1

In contrast to experimental example 1, the coagulation bath and rinsing bath for dry-jet wet spinning was not provided with the automatic control device for fiber width as described in the above-mentioned example, but with the fiber width adjusting device shown in fig. 4. Other process conditions remained the same as experimental example 1.

Before running, the fiber width adjusting device shown in fig. 4 was installed in a coagulation bath and a rinsing bath according to empirical values. However, when the fiber bundle is running, the phenomenon of fiber bundle overlapping or filament floating exists, and the width of the fiber bundle cannot be well controlled, but due to the influence of the solvent and the temperature in the tank, the width of the fiber at the spinning position at the edge can only be adjusted manually, but the width of the fiber at the middle spinning position cannot be adjusted (because the screws at the middle spinning position cannot be twisted, the potential safety hazard exists).

The fiber tow of the comparative example was observed to have a phenomenon of filament flying during running, and the fiber tow was easily entangled with a roll on a coagulation bath pulling-out roll, and the properties of the filaments at the spinning position were measured as shown in table 1.

Comparative example 2

In contrast to experimental example 2, the coagulation bath and rinsing bath for wet spinning was not provided with the automatic control device for fiber width as described in the above example, but with the fiber width adjusting device shown in fig. 5. Other process conditions and strand specifications remained the same as experimental example 2.

Before running, the fiber width adjusting device shown in fig. 5 was installed in a coagulation bath and a rinsing bath according to empirical values. However, when the fiber bundle is running, the phenomenon of fiber bundle overlapping or single fiber floating exists, and the width of the fiber bundle cannot be well controlled, but due to the influence of the solvent and the temperature in the tank, the fiber width of the spinning position at the edge can only be adjusted manually, but the fiber width of the spinning position in the middle cannot be adjusted (because the screws at the edge cannot be twisted, the potential safety hazard exists).

In the operation process, the phenomenon of yarn crossing of adjacent spinning positions can be seen, the roller winding is generated on the water washing driving roller, the production stability is not facilitated, and the protofilament performance of the spinning positions is tested, as shown in table 1.

TABLE 1

As can be seen from table 1: the strength dispersion coefficient of the polyacrylonitrile protofilament prepared by the experimental example of the invention is obviously lower than that of a comparative example, and the stability of the production quality is facilitated. In addition, the content of dimethyl sulfoxide in the polyacrylonitrile protofilament prepared by the experimental example of the invention is obviously lower than that of the comparative example. The roller winding times of the experimental embodiment of the invention are obviously reduced, which is beneficial to the stability of the production quality and reduces the dispersion coefficient of the performance index of the product.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and any simple modification, equivalent change and modification made to the above embodiment according to the technical spirit of the present invention are still within the scope of the technical solution of the present invention.

Claims (10)

1. An automatic control device of fiber width is characterized by comprising:

a cross member;

the fiber width adjusting structure comprises a first moving part and a second moving part which are oppositely arranged; one end of the first moving part and one end of the second moving part are respectively connected with the transverse part in a sliding manner; the width of the fiber tows is limited through the distance between the first moving piece and the second moving piece;

the automatic control system comprises an automatic driving control mechanism and a transmission structure; the automatic driving control mechanism is in driving connection with a transmission structure, and the transmission structure is connected with the first moving piece and the second moving piece and used for driving the first moving piece and the second moving piece to transversely slide on the transverse piece;

the automatic driving control mechanism drives the transmission structure to move, so that the first moving piece and the second moving piece are driven to transversely slide on the transverse piece, and the distance between the first moving piece and the second moving piece is adjusted to automatically control the width of the fiber tows.

2. The automated control device of fiber width according to claim 1, wherein the automated drive control mechanism comprises:

an automatic distributor of gas source;

the diaphragm divides the cavity into a first closed cavity and a second closed cavity; an elastic piece is arranged on the inner wall of the cavity of the second cavity and connected with the diaphragm; the diaphragm is an elastic body and can deform under the action of force, so that a stressed part of the diaphragm moves towards a first direction or a direction opposite to the first direction; when the stressed part of the diaphragm moves towards the first direction under the action of force, the diaphragm compresses the elastic piece;

one end of the air inlet pipeline is connected with the automatic air source distributor, and the other end of the air inlet pipeline is connected with the first cavity; the automatic gas source distributor is used for introducing distributed compressed gas with set pressure into the first cavity through a gas inlet pipeline and pushing the stressed part of the diaphragm to move towards a first direction;

one end of the driving rod is positioned in the first cavity and connected with the diaphragm, and the other end of the driving rod is positioned outside the cavity and connected with the transmission structure in a driving way; wherein the driving rod moves along a first direction or a direction opposite to the first direction along with the force-bearing part of the diaphragm;

preferably, the elastic member is a spring;

preferably, the membrane comprises an edge part and a stressed part; wherein the edge portion is connected with the inner wall of the cavity; the driving rod and the elastic piece are connected with the stress part of the diaphragm.

3. The automated control device of fiber width according to claim 2, wherein the automated drive control mechanism further comprises:

and one end of the feedback air pipe is communicated with the first cavity, and the other end of the feedback air pipe is connected with the automatic air source distributor and used for feeding back the pressure of the compressed air in the first cavity to the automatic air source distributor.

4. The automated control device of fiber width according to any one of claims 1-3, wherein the transmission structure comprises:

a longitudinal slide rail;

a slider disposed in the longitudinal slide; the automatic driving control mechanism is in driving connection with the sliding block and is used for driving the sliding block to longitudinally move in the longitudinal sliding rail;

a first movable bar having a first end and a second end disposed opposite to each other; the first end of the first movable rod is connected with the sliding block, and the second end of the first movable rod is connected with the first moving piece;

a second movable bar having a first end and a second end disposed opposite to each other; the first end of the second movable rod is connected with the sliding block, and the second end of the second movable rod is connected with the second moving piece;

when the automatic driving control mechanism drives the sliding block to longitudinally move in the longitudinal sliding rail, the first movable rod and the second movable rod which are connected with the sliding block drive the first moving piece and the second moving piece to transversely move on the transverse piece.

5. The automatic control device of fiber width according to claim 4,

when the sliding block slides to the lowest end of the longitudinal sliding rail, the included angle between the first movable rod and the longitudinal sliding rail and the included angle between the second movable rod and the longitudinal sliding rail are larger than 45 degrees; and/or

When the sliding block slides to the uppermost end of the longitudinal sliding rail; the included angle between the first movable rod and the longitudinal slide rail and the included angle between the second movable rod and the longitudinal slide rail are more than or equal to 15 degrees and less than 45 degrees; and/or

The length of the longitudinal slide rail ensures that the distance between the first moving part and the second moving part is not more than 15cm.

6. The automated control device of fiber width according to any one of claims 1 to 5,

the first moving part comprises a first moving rod and a first sliding structure; one end of the first moving rod is connected with the transverse piece in a sliding mode through a first sliding structure; the first movable rod is connected with the first sliding structure; and/or

The second moving part comprises a second moving rod and a second sliding structure; one end of the second moving rod is connected with the transverse piece in a sliding mode through a second sliding structure; the second movable rod is connected with the second sliding structure; and/or

The cross member is a cross bar.

7. The automatic control device for fiber width according to any one of claims 1 to 6, characterized in that the number of the fiber width adjusting structures is at least one; the number of the automatic control systems is consistent with that of the fiber width adjusting structures, and the automatic control systems are in one-to-one corresponding driving connection.

8. The automated control device for fiber width according to claim 7, wherein when the fiber width adjusting structure is plural, the plural fiber width adjusting structures are connected to the cross member in a sliding manner.

9. A preparation method of polyacrylonitrile protofilament is characterized in that in the preparation of the polyacrylonitrile protofilament: the automatic control device for the fiber width of any one of claims 1 to 8 is used for automatically and quantitatively controlling the width of the fiber tows in any one or more of the processes of solidification forming, washing and oiling.

10. The method for preparing polyacrylonitrile precursor according to claim 9, wherein in any one of the processes of solidification forming, washing and oiling, the step of automatically and quantitatively controlling the width of the fiber tows comprises the following steps:

controlling a first moving member and a second moving member in the automatic fiber width control device corresponding to each spinning position to transversely slide on the transverse member and move to a preset position, so that the first moving member and the second moving member are positioned at two sides of a running fiber tow corresponding to the spinning position;

in the running process of the fiber tows, the air source pressure of the air source automatic distributor is adjusted, so that the first moving piece and the second moving piece of the first spinning position control the width of the fiber tows to a set width, and the air source pressure value at the moment is recorded as a standard set value;

and setting the air source pressures corresponding to other spinning positions to the standard set value so as to control the width of the fiber tows of other spinning positions to the set width.

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