A method for preparing a high-strength industrial yarn without sizing

Abstract

The application relates to a preparation method of a high-strength industrial yarn without sizing, wherein the high-strength industrial yarn without network effect is subjected to a pre-tension and then subjected to a network to obtain the high-strength industrial yarn without sizing; the main network nozzle of the network comprises a guide I, a guide II, a bottom plate, a gasket and a cover plate; the guide I and the guide II are respectively arranged on the upper and lower sides of the bottom plate; the bottom plate and the cover plate are separated by the gasket to form a fixed-width thread path for the thread bundle to pass through; the bottom plate is in the form of a cuboid, a plane on the side of the bottom plate facing the cover plate is provided with two airflow nozzles with inner cylindrical shapes, which are a nozzle I and a nozzle II; the nozzle I, the nozzle II and the central axis of the thread bundle are perpendicular to each other and intersect at the same point; compressed air flows with the same pressure are sprayed from the nozzles, intersect with each other and form network nodes on the thread bundle. The high-strength industrial yarn is subjected to the network through the network technology once, and the effect of the high-strength industrial yarn without sizing is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of spinning, and relates to a preparation method of high-strength industrial yarn without sizing. BACKGROUND

[0002] Network technology is a technology for increasing the cohesion between single filaments of a fiber bundle by means of high-pressure airflow jetting to form continuous network nodes between the single filaments of the fiber bundle passing through the main network device, so as to improve the production stability.

[0003] In the 1960s, DuPont Company of the United States invented network processing technology, and network technology has been widely applied in production since the 1970s, becoming the third method for bundling long yarns after twisting and sizing.

[0004] The original purpose of the birth of network technology is to replace sizing. Compared with the twisting method, network technology is faster and can meet the requirements of high-speed and continuous spinning, so network technology develops very quickly at the beginning.

[0005] However, with the continuous development of fiber technology, the strength of the fiber gradually increases, and high-strength industrial yarns with higher strength than civil yarns are born. Such fibers have higher mechanical properties, and the tensile breaking strength is often more than 8.0 cN / dtex, so that such fibers are not easy to deform or stretch under external forces such as compressed air compared with ordinary civil yarns. This increases the difficulty of fiber network. If only the network air pressure is increased to try to solve this problem, excessive network air pressure may cause the fiber in the network device to be unstable, collide with the inner wall of the network device, and cause hair and broken yarns, and also easily cause uneven distribution of network nodes. On the other hand, the fineness of industrial yarns is often larger than that of civil yarns. The fineness of the multifilament is less than 500D, which is classified as fine industrial yarns. The actual multifilament fineness is generally higher than 300D or even 500D. The fineness of the single filament in the multifilament is generally more than 4D for polyester, and more than 8D for nylon, which is thicker than civil yarns or fine industrial yarns. Such high-fineness fibers are more difficult to twist and are more difficult to open and maintain high network firmness. Just like thicker ropes are more difficult to knot, and thinner ropes are more difficult to untie. Moreover, the high fineness of the single filament will slow down the cooling speed of the fiber, and the fiber still has a high temperature when it reaches the network device. The internal high molecular chain has strong activity. Once the fiber collides and scratches with the main network device under the action of the network airflow, the damage is more serious.

[0006] The patent CN114318619A provides a method for improving the network firmness of network multifilament, designs a new main network nozzle, which has two nozzles and can form vortex action in different rotating directions in the filament path; wherein, the gas pressure of the gas flow shot by nozzle I is 0.1-0.3 MPa, which determines the deflection direction of the multifilament network, the gas flow direction is not aligned with the center axis of the filament path, but only acts on the filaments outside the multifilament, the shot gas flow forms a rotating vortex in the filament path, which makes the outside filaments wrap the inside filaments; the gas pressure of the gas flow shot by nozzle II is 0.05-0.08 MPa, the rotating vortex formed by the gas flow is opposite to that of nozzle I, nozzle II does not change the deflection direction of the network node, but only disrupts the direction of the network node, making the network firmness better and not easy to separate, so the gas flow pressure is smaller. The two nozzles use intermittent gas flow with equal opening and closing time, which is constantly recycled. The network firmness of this method reaches 97-99%, can form 30-150 dtex / 10-40 F polyester network multifilament, eliminates the steps of twisting or sizing, and shortens the weaving process; however, in order to ensure that the rotating vortex formed by nozzle I and nozzle II acts on the same position of the filament bundle, the opening and closing time of the intermittent gas flow, the gas pressure values of the two nozzles and the phase difference between them need to be set in detail, and the control is complex.

[0007] Patent CN114318617A provides a network composite yarn and its network method and application, using double-nozzle nozzle, nozzle I and nozzle II intermittently inject compressed air flow into the yarn channel, the air flow opens the network forming interlacing part to the multifilament bundle, and closes the fiber opening part. By adjusting the time difference of the air flow of the two nozzles, the staggered network of nozzle I and nozzle II is controlled to avoid the overlap of interlacing part I and interlacing part II, forming 30-150 dtex / 10-40F fine denier DTY network composite yarn composed of continuous several cycle units, each cycle unit is composed of fiber opening part I, interlacing part I, fiber opening part II and interlacing part II connected in sequence; wherein the air pressure of nozzle I air flow is 0.2-0.3 MPa, forming interlacing part I, network firmness is 85-95%, network degree is 20-50 / m; the air pressure of nozzle II air flow is 0.05-0.1 MPa, forming interlacing part II, network firmness is 40-60%, network degree is 20-50 / m. The technical solution, through two network nozzles for twice network of composite yarn, needs to set the opening and closing time of air flow, the air pressure value of two nozzles and the phase difference between them in detail, the control is relatively complex; the method controls the network firmness of interlacing part I and interlacing part II to be different, so that interlacing part II has lower network firmness, and the network node is easy to loosen, so as to form the structure of partial interlacing and partial loosening of the multifilament, which can achieve the requirements of no twisting and no sizing, but this structure only networks the multifilament when the nozzle of the network nozzle blows air, and no network node is generated when the air flow is closed, which makes the network node in the upper part of the multifilament distribute densely, and the other part has no network node at all, which undoubtedly limits the uniformity of the network node distribution on the multifilament and the further improvement of the network degree.

[0008] Although the above two methods have good network effect and can achieve the requirements of no sizing, they can only meet the sizing-free network process of fibers with a multifilament fineness lower than 300D. If the multifilament fineness is too high, due to the high mechanical strength and high single filament fineness of industrial yarn, it is difficult for the single air flow to make the fiber deform and form network nodes with other single filaments in the multifilament.

[0009] Therefore, it is of great significance to study a preparation method of sizing-free high-strength industrial yarn and a special main network nozzle thereof to solve the problem of high-strength industrial yarn not being easy to be networked, and to obtain efficient and uniform network effect. SUMMARY

[0010] The purpose of the present application is to solve the problem of high-strength industrial yarn, especially coarse denier high-strength industrial yarn not being easy to be networked in the prior art, and to provide a preparation method of sizing-free high-strength industrial yarn.

[0011] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0012] A method for preparing a high-strength industrial yarn without sizing, wherein the high-strength industrial yarn without network effect is subjected to a pre-tension and then a network to obtain the high-strength industrial yarn without sizing.

[0013] The high-strength industrial yarn without network effect has a tensile breaking strength of 8.5 cN / dtex or above.

[0014] The main network nozzle comprises a guide I, a guide II, a base plate, a gasket and a cover plate.

[0015] The guide I and the guide II are respectively located on the upper and lower sides of the base plate, and the base plate and the cover plate are separated by the gasket to form a fixed-width thread path for the thread bundle to pass through. The thread bundle without network effect is guided by the guide I and then enters the thread path between the base plate and the cover plate after being subjected to a pre-tension.

[0016] The base plate is in the form of a cuboid, and two airflow nozzles, namely nozzle I and nozzle II, are opened on the plane of the base plate facing the cover plate. The nozzle I, the nozzle II and the central axis of the thread bundle are perpendicular to each other and intersect at the same point. The central axes of the nozzle I and the nozzle II form a 45° angle with the plane of the base plate facing the cover plate. The two nozzles are obliquely through the entire base plate and are connected to a compressed air source on the other side of the base plate. After the thread bundle entering the thread path reaches the intersection point in the direction of the nozzles, network nodes are formed under the action of compressed air from the nozzle I and the nozzle II. The thread bundle is pulled out of the main network nozzle by the guide II, thereby forming the high-strength industrial yarn without sizing.

[0017] The airflow emitted from the nozzle I and the nozzle II is a stable airflow with constant air pressure and the same pressure.

[0018] As a preferred technical solution:

[0019] The base plate and the cover plate are connected and fixed by an internal hexagonal screw. The base plate and the cover plate are separated by a gasket to form a fixed-width thread path for the thread bundle to pass through. The thickness of the gasket is the diameter of the thread path. 。

[0020] The diameter of the thread path is 0.8-2.5 mm.

[0021] The diameters of the nozzle I and the nozzle II are the same, both being 1.2-2.5 mm.

[0022] The pressure of the airflow emitted from the nozzle I and the nozzle II is 0.28-0.45 MPa.

[0023] The method for preparing the high-strength industrial yarn without sizing as described above, the advancing speed of the high-strength industrial yarn in the yarn path is 2500-3500 m / min.

[0024] The method for preparing the high-strength industrial yarn without sizing as described above, the pre-tension received by the high-strength industrial yarn is 0.05 cN / D.

[0025] The method for preparing the high-strength industrial yarn without sizing as described above, the high-strength industrial yarn is PET, PA6 or PA66, and the specification is 300-800 D / 72-144 F.

[0026] The method for preparing the high-strength industrial yarn without sizing as described above, the tensile breaking strength of the high-strength industrial yarn without sizing is 7.8 cN / dtex or above, and the tensile breaking strength is tested according to the GB / T14344-2008 standard.

[0027] The method for preparing the high-strength industrial yarn without sizing as described above, the network degree of the high-strength industrial yarn without sizing is 16-25 / m, and the network firmness is 90-95%, which meets the use requirements of the high-strength industrial yarn without sizing, and the measurement method of the network degree and the network firmness is according to the FZ / T50001-2016 "Synthetic fiber filament network degree test method".

[0028] Invention principle:

[0029] In the network process, the network node direction is mainly formed by the air flow blowing the yarn bundle, so that the single filaments in the yarn bundle are intertwined with each other, the more single filaments participating in the intertwining, the more complex the intertwining structure, and the higher the network firmness. Compared with fine denier industrial yarn, the industrial yarn has higher fineness, and the multi-filament fineness formed by the yarn bundle often reaches 300D or even 500D or above, and the single filament fineness reaches 5D or even 8D, which has higher tensile breaking strength, which makes it more difficult to network them, mainly manifested as: the industrial yarn with high single filament fineness, fewer single filaments in the multi-filament, and stronger mechanical strength cannot be twisted by multiple single filaments under the action of air flow blowing, and it is difficult to intertwine under external force; and even if the single filaments are intertwined and form a certain network node, due to the small number of single filaments, the structure of the network node is often relatively simple, and compared with the network node formed by more single filaments, it is often more easily loosened and not easy to maintain high network firmness. In view of the problems existing in the existing network technology, the application provides a method for preparing high-strength industrial yarn without sizing and a special main network nozzle thereof, and the generated high-strength industrial yarn without sizing has the advantages of simple network process, uniform distribution of network nodes, and network firmness meeting the use requirements of high-strength industrial yarn.

[0030] The traditional main network technology relies on the high-pressure jet flow of a single jet on the main network nozzle to transversely impact the composite filament passing through the network device filament channel, to generate vortexes parallel to the filament bundle, to make each single filament generate two saddle-shaped movements and high-frequency wavy reciprocations. The deflected airflow makes the single filaments be bundled and accelerated to different degrees, and the single filaments carried by the two airflows converge and intertwine when they meet in the filament channel, to generate intertwining points in the axial direction of the filament bundle. However, considering the higher fineness and strength of industrial filaments, the fewer number of single filament roots in the multifilament formed by the filament bundle makes it difficult for the industrial filaments to stretch and twist under the blowing of the airflow, to form complex network nodes with each other, and finally to form a higher network degree and network firmness.

[0031] The main network nozzle of the application is provided with a jet I and a jet II, wherein the jet I, the jet II and the central axis of the filament bundle are perpendicular to each other and intersect at the same point, the compressed air blown by the two jets collides and interacts at the position of the filament bundle, interferes with each other and disrupts the original fixed blowing direction of the airflow of the two jets, to form complex multidirectional vortexes in the filament channel, and the filament bundle is disturbed by the multidirectional vortexes after entering the filament channel. Compared with the airflow coming from the fixed unidirectional or bidirectional airflow, the vortex does not only blow in a single direction, and is not easy to cause the filament bundle to be blown too violently, to collide with the inner wall of the filament channel and further cause the problems of hairiness and broken filament, and the filament channel is an open structure, rather than the closed cylindrical structure of the conventional network device filament channel, so that the collision probability of the filament bundle with the inner wall of the filament channel is further reduced, and the blowing airflow pressure can be moderately increased to meet the network requirements of high-strength industrial filaments; at the same time, the movement and blowing form of the vortex in the filament channel are more complex, which can drive the single filament to form more complex intertwining, to make up for the problem that the number of single filament roots in the industrial filament is small and it is not easy to form network points. Since the airflow comes from different directions, network nodes can be formed on different side directions of the filament bundle, the network nodes are good in uniformity in each direction, and are not easy to be loosened. The network firmness of high-strength industrial filaments reaches 90-95%, which can meet the requirements of high-strength industrial filaments on network firmness.

[0032] In order to meet the requirements of high-strength industrial filaments on the network degree, under the condition of the primary network technology (i.e. the jet I and the jet II blow the same position on the filament bundle at the same time), the application uses constant-pressure stable airflow, which is continuous and constant, and network nodes can be formed at each position in the process of winding the filament bundle, and the distribution of the network nodes is good in uniformity.

[0033] The patent CN114318619A carries out the network through the intermittent airflow, if it is replaced by the constant pressure stable airflow, there is the risk of reducing the network firmness, and it is more unable to meet the requirements of high strength industrial yarn, because if the constant pressure stable airflow is used, on the one hand, the constant pressure airflow of the nozzle I will produce a continuous disturbance to the yarn when the yarn is networked, so that the nozzle II is difficult to accurately blow the single yarn on the side of the yarn, which affects the effect of the nozzle II on the single yarn in the opposite direction, and on the other hand, the nozzle I and the nozzle II are not opposite to the central axis of the yarn channel, but only act on the single yarn outside the center of the yarn, and form two vortexes with opposite rotating directions in the yarn channel, if it is replaced by the constant pressure stable airflow, it will cause the two nozzles to blow a large amount of gas, and the two opposite vortexes will be offset, affecting the network effect.

[0034] If the patent CN114318617A is replaced by the constant pressure stable airflow, the original process planning of the nozzle I and the nozzle II for alternating network of the yarn will be disturbed, the original interlacing part I and the interlacing part II will be overlapped, the nozzle II will blow the network nodes formed at the nozzle I without changing the direction, which will damage the network effect, and the blowing directions of the nozzle I and the nozzle II are the same, the constant pressure stable airflow of the two nozzles will continuously push the yarn, so that the actual running path of the yarn will be greatly deviated from the positions away from the nozzle I and the nozzle II, and the network effect of the two nozzles will be weakened.

[0035] Since the present application only needs one network, it does not need other processing on the same position of the yarn through secondary network, only needs to form uniform network nodes on the yarn by controlling the air pressure value of the constant pressure stable airflow, and ensures that the number of network nodes per unit length meets the requirements, so there is no problem of uneven distribution of network nodes caused by intermittent airflow, which can only form network nodes on the yarn when the airflow is turned on. This optimizes the control system of the complex intermittent airflow frequency, phase difference and air pressure of other double-nozzle network technologies, and only needs to control one parameter, air pressure.

[0036] Advantages:

[0037] (1) Compared with the existing multifilament network technology, the present application is mainly applied to industrial yarn network technology, and solves the problem that industrial yarn is not easy to be networked due to high mechanical strength, large fiber fineness and small number of single yarn.

[0038] (2) Compared with the existing multifilament network technology, the present application uses one network technology, does not need additional twisting, mercerizing and other auxiliary processes, does not need complex multiple network to improve the network degree and network firmness, uses the constant pressure stable airflow for network, needs fewer process parameters to be controlled, the complexity of the equipment is low, the network process is simple, can effectively replace the sizing technology, saves the production cost, and avoids the environmental pollution caused by sizing.

[0039] (2) The vortex formed by the double-nozzle cross airflow of the application blows on each filament in the filament bundle uniformly, and is not prone to problems such as hairiness and broken filaments, and can form network nodes in different directions on the side of the filament bundle, and the network nodes are good in uniformity in each direction and are not prone to opening.

[0040] (3) The application can be applied to the network process of high-strength industrial filaments of various different high molecular fibers such as PET, PA6 and PA66, and has a wide application range. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 A side view of a main network nozzle used in the application;

[0042] Figure 2 A top view of a main network nozzle used in the application;

[0043] Figure 3 A top view of a base plate of a main network nozzle used in the application;

[0044] Figure 4 A front view (half section) of a main network nozzle used in the application;

[0045] Figure 5 A structural schematic view of a main network nozzle used in the application;

[0046] Figure 6 A structural schematic view of a base plate;

[0047] Wherein, 1 - guide I, 2 - guide II, 3 - base plate, 4 - gasket, 5 - cover plate, 6 - inner hexagonal screw, 7 - nozzle I, 8 - nozzle II. DETAILED DESCRIPTION

[0048] The application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the application and not to limit the scope of the application. In addition, it should be understood that those skilled in the art can make various modifications or changes to the application after reading the content taught by the application, and these equivalent forms also fall within the scope defined by the appended claims of the application.

[0049] The test method used in the application is as follows:

[0050] Tensile breaking strength: tested in accordance with GB / T14344-2008 standard.

[0051] Network degree and network firmness: tested in accordance with FZ / T50001-2016 "Synthetic fiber filament network degree test method".

[0052] Example 1

[0053] A preparation method of a high-strength industrial yarn without sizing, the specific process being as follows:

[0054] The high-strength industrial yarn without network effect is subjected to one network to obtain the high-strength industrial yarn without sizing after a pre-tension of 0.05 cN / D is applied;

[0055] The high-strength industrial yarn without network effect is PET, with a specification of 300D / 72F and a tensile breaking strength of 8.6 cN / dtex;

[0056] As shown in Figures 1-5 The main network nozzle used by the network comprises a guide I1, a guide II 2, a base plate 3, a gasket 4 and a cover plate 5;

[0057] The guide I1 and the guide II 2 are respectively located on the upper and lower sides of the base plate 3, the base plate 3 and the cover plate 5 are separated by the gasket 4 to form a filament path with a diameter of 2.5 mm for the passage of the filament bundle, and the base plate 3 and the cover plate 5 are connected and fixed by an internal hexagonal screw 6;

[0058] As shown in Figure 6 The base plate 3 is in the form of a cuboid, two airflow nozzles are opened on the plane of the base plate towards the cover plate, which are nozzle I 7 and nozzle II 8, the diameters of the nozzle I 7 and the nozzle II 8 are the same, both being 1.2 mm; the nozzle I 7, the nozzle II 8 and the central axis of the filament bundle are perpendicular to each other and intersect at the same point, the central axes of the nozzle I 7 and the nozzle II 8 respectively form a 45° angle with the plane of the base plate 3 towards the cover plate, the airflow emitted by the nozzle I 7 and the nozzle II 8 is a stable airflow with constant air pressure, both being 0.28 MPa; the advancing speed of the multifilament in the filament path is 2500 m / min.

[0059] The tensile breaking strength of the high-strength industrial yarn without sizing obtained is 8 cN / dtex, the network degree is 21 / m, and the network firmness is 94%.

[0060] Example 2

[0061] A preparation method of a high-strength industrial yarn without sizing, the specific process being as follows:

[0062] The high-strength industrial yarn without network effect is subjected to one network to obtain the high-strength industrial yarn without sizing after a pre-tension of 0.05 cN / D is applied;

[0063] The high-strength industrial yarn without network effect is PA6, with a specification of 500D / 72F and a tensile breaking strength of 9.5 cN / dtex;

[0064] The main network nozzle used by the network comprises a guide I, a guide II, a base plate, a gasket and a cover plate;

[0065] The guide wire I and the guide wire II are respectively located on the upper and lower sides of the bottom plate, the middle of the bottom plate and the cover plate is separated by a gasket to form a 2.5mm diameter wire channel for the wire bundle to pass through, and the bottom plate and the cover plate are connected and fixed by an internal hex screw;

[0066] The bottom plate is a cuboid, two airflow nozzles, nozzle I and nozzle II, are opened on the plane of the side of the bottom plate facing the cover plate, the diameters of the nozzle I and the nozzle II are the same, both being 1.5mm; the nozzle I, the nozzle II and the center axis of the wire bundle are perpendicular to each other and intersect at the same point, the center axis of the nozzle I and the nozzle II respectively form a 45° angle with the plane of the side of the bottom plate facing the cover plate, the airflow emitted by the nozzle I and the nozzle II is a stable airflow with constant air pressure, both being 0.3MPa; the advancing speed of the multifilament in the wire channel is 2800m / min.

[0067] The tensile breaking strength of the prepared non-sizing high-strength industrial yarn is 8.8cN / dtex, the network degree is 25 / m, and the network firmness is 91%.

[0068] Example 3

[0069] A method for preparing a non-sizing high-strength industrial yarn, the specific process is as follows:

[0070] The high-strength industrial yarn without network effect is subjected to a pre-tension of 0.05cN / D, and then subjected to a network to obtain a non-sizing high-strength industrial yarn;

[0071] The high-strength industrial yarn without network effect is PET, with a specification of 800D / 144F, and a tensile breaking strength of 8.5cN / dtex;

[0072] The main network nozzle used in the network includes a guide wire I, a guide wire II, a bottom plate, a gasket and a cover plate;

[0073] The guide wire I and the guide wire II are respectively located on the upper and lower sides of the bottom plate, the middle of the bottom plate and the cover plate is separated by a gasket to form a 2.5mm diameter wire channel for the wire bundle to pass through, and the bottom plate and the cover plate are connected and fixed by an internal hex screw;

[0074] The bottom plate is a cuboid, two airflow nozzles, nozzle I and nozzle II, are opened on the plane of the side of the bottom plate facing the cover plate, the diameters of the nozzle I and the nozzle II are the same, both being 1.8mm; the nozzle I, the nozzle II and the center axis of the wire bundle are perpendicular to each other and intersect at the same point, the center axis of the nozzle I and the nozzle II respectively form a 45° angle with the plane of the side of the bottom plate facing the cover plate, the airflow emitted by the nozzle I and the nozzle II is a stable airflow with constant air pressure, both being 0.35MPa; the advancing speed of the multifilament in the wire channel is 3000m / min.

[0075] The tensile breaking strength of the prepared non-sliming high-strength industrial yarn is 7.8 cN / dtex, the network degree is 19 / m, and the network firmness is 90%.

[0076] Example 4

[0077] A method for preparing a non-sliming high-strength industrial yarn, the specific process being as follows:

[0078] The non-sliming high-strength industrial yarn is prepared by one network after applying a pre-tension of 0.05 cN / D;

[0079] The non-networked high-strength industrial yarn is PA66, with a specification of 500D / 72F and a tensile breaking strength of 11.8 cN / dtex;

[0080] The main network nozzle used in the network includes a guide I, a guide II, a bottom plate, a gasket, and a cover plate;

[0081] The guide I and the guide II are respectively located on the upper and lower sides of the bottom plate, the bottom plate and the cover plate are separated by the gasket in the middle to form a yarn channel with a diameter of 2.5 mm for the passage of the yarn bundle, and the bottom plate and the cover plate are connected and fixed by an internal hexagonal screw;

[0082] The bottom plate is in the form of a rectangular parallelepiped, two airflow nozzles, nozzle I and nozzle II, are opened on the plane of the side of the bottom plate facing the cover plate, the diameters of the nozzle I and the nozzle II are the same, both being 2 mm; the nozzle I, the nozzle II, and the central axis of the yarn bundle are perpendicular to each other and intersect at the same point, the central axes of the nozzle I and the nozzle II respectively form a 45° angle with the plane of the side of the bottom plate facing the cover plate, the airflow emitted by the nozzle I and the nozzle II is a stable airflow with constant air pressure, both being 0.4 MPa; the advancing speed of the multifilament in the yarn channel is 3200 m / min.

[0083] The tensile breaking strength of the prepared non-sliming high-strength industrial yarn is 10.5 cN / dtex, the network degree is 18 / m, and the network firmness is 95%.

[0084] Example 5

[0085] A method for preparing a non-sliming high-strength industrial yarn, the specific process being as follows:

[0086] The non-sliming high-strength industrial yarn is prepared by one network after applying a pre-tension of 0.05 cN / D;

[0087] The non-networked high-strength industrial yarn is PA66, with a specification of 800D / 96F and a tensile breaking strength of 10.2 cN / dtex;

[0088] The main network nozzle used in the network includes a guide I, a guide II, a bottom plate, a gasket, and a cover plate;

[0089] The guide wire I and the guide wire II are respectively located on the upper and lower sides of the bottom plate, the bottom plate and the cover plate are separated by a gasket in the middle to form a wire channel with a diameter of 2.5mm for the wire bundle to pass through, and the bottom plate and the cover plate are connected and fixed by an internal hex screw;

[0090] The bottom plate is in the form of a cuboid, two airflow nozzles, nozzle I and nozzle II, are opened on the plane of the side of the bottom plate facing the cover plate, the diameters of the nozzle I and the nozzle II are the same, both are 2.5mm; the nozzle I, the nozzle II and the central axis of the wire bundle are perpendicular to each other and intersect at the same point, the central axis of the nozzle I and the nozzle II respectively form a 45° angle with the plane of the side of the bottom plate facing the cover plate, the airflow emitted by the nozzle I and the nozzle II is a stable airflow with constant air pressure, both are 0.45MPa; the advancing speed of the multifilament in the wire channel is 3500m / min.

[0091] The tensile breaking strength of the prepared high-strength industrial yarn without sizing is 9.1cN / dtex, the network degree is 16 / m, and the network firmness is 92%.

Claims

1. A method for preparing high-strength industrial yarn without sizing, characterized in that: The high-strength industrial yarn that has not been networked is produced by applying pre-tension and then passing it through a network once to obtain the sizing-free high-strength industrial yarn. The main network nozzles used in the network include wire guide I (1), wire guide II (2), base plate (3), gasket (4) and cover plate (5); Guide wire I (1) and guide wire II (2) are located on the upper and lower sides of the base plate (3) respectively. The base plate (3) and the cover plate (5) are separated by a gasket (4) to form a fixed width of the wire channel for the wire bundle to pass through. The base plate (3) is rectangular. Two airflow nozzles are opened on the plane of the base plate (3) facing the cover plate (5), namely nozzle I (7) and nozzle II (8). The central axes of nozzle I (7), nozzle II (8) and the filament bundle are perpendicular to each other and intersect at the same point. The central axes of nozzle I (7) and nozzle II (8) form a 45° angle with the plane of the base plate (3) facing the cover plate. The airflow ejected from nozzle I (7) and nozzle II (8) is a stable airflow with constant pressure and the same pressure. The diameters of nozzle I (7) and nozzle II (8) are the same, both being 1.2~2.5 mm; The advancing speed of high-strength industrial filament within the filament path is 2500~3500 m / min; The pre-tension applied to the high-strength industrial yarn is 0.05 cN / D; The network density of the un-sized high-strength industrial yarn is 16~25 cells / m, and the network strength is 90~95%.

2. The method for preparing a sizing-free high-strength industrial yarn according to claim 1, characterized in that, The base plate (3) and the cover plate (5) are connected and fixed by internal hex screws (6).

3. The method for preparing a sizing-free high-strength industrial yarn according to claim 1, characterized in that, The diameter of the silk channel is 0.8~2.5 mm.

4. The method for preparing a sizing-free high-strength industrial yarn according to claim 1, characterized in that, The pressure of the airflow ejected from nozzle I (7) and nozzle II (8) is 0.28~0.45 MPa.

5. The method for preparing a sizing-free high-strength industrial yarn according to claim 1, characterized in that, The types of high-strength industrial yarn are PET, PA6 or PA66, with specifications of 300~800 D / 72~144 F.

6. The method for preparing a sizing-free high-strength industrial yarn according to claim 1, characterized in that, The tensile breaking strength of the high-strength industrial yarn that does not require sizing is above 7.8 cN / dtex.

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