A fiber-reinforced composite static ring and a method for manufacturing the same

Abstract

The present application relates to the field of composite materials, and particularly relates to a kind of fiber reinforced composite material static ring and its preparation method.The preparation method provided by the present application first twists aramid fiber and nylon fiber to prepare core line, then, the surface of the core line is coated with cotton and hemp fiber to obtain coated yarn;Then, the coated yarn is woven into a strip by the shuttle weaving process;After that, the strip obtained in step (B) is impregnated with a specific glue solution, then dried to obtain a prepreg;Then, the obtained prepreg is wound and formed on an annular mold to form a ring-shaped sample;Then, the ring-shaped sample is placed in a mold for mold pressing and curing to form a fiber reinforced composite material static ring.The static ring obtained by the present application has excellent impact strength, compressive strength, water absorption, wear resistance and the like, which ensures the performance requirements of the ship stern shaft sealing friction pair.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of composite materials, in particular to a fiber-reinforced composite material static ring and a preparation method thereof. BACKGROUND

[0002] The function of mechanical seal depends on a set of friction pairs, and the static ring, as a core component, together with the dynamic ring, forms the end face friction pair (as shown in FIG. 1, wherein 1 is the dynamic ring and 2 is the static ring), and bears multiple key functions such as sealing and buffering. The material of the static ring of the mechanical seal needs to have properties such as wear resistance, corrosion resistance, self-lubrication, good thermal conductivity, and low linear expansion coefficient, and common types include: graphite materials (pure graphite, resin-impregnated graphite, metal-impregnated graphite), engineering ceramic materials (silicon carbide SiC, alumina ceramic Al2O3, silicon nitride Si3N4), hard alloy materials, and polymer materials (polytetrafluoroethylene PTFE, nylon PA), etc. Figure 1 The stern shaft sealing device plays an indispensable role in the ship propulsion system, which is crucial for ensuring the stable operation of the ship power transmission system and preventing seawater intrusion and lubricating oil leakage. There are various forms of stern shaft sealing devices, and mechanical seal is one of the most widely used types. In the mechanical seal device applied to the stern shaft sealing device, the static ring is always in close contact with the dynamic ring with the help of the elastic compensation mechanism, forming a liquid film barrier between them, effectively blocking the intrusion of seawater and the leakage of lubricating oil. This layer of liquid film acts as a strong defense line, ensuring the sealing of the stern shaft sealing device and maintaining the normal operation of the ship propulsion system.

[0003] However, the working environment of the static ring of the stern shaft sealing device is extremely complex and harsh. From the perspective of mechanical load, shaft system vibration, propeller thrust fluctuation, and ship collision can all exert different degrees of force on the static ring. When the ship is sailing, the periodic thrust of the propeller and the shaft system vibration will produce high-frequency impact, which will continuously act on the static ring and test its structural strength. In extreme working conditions, such as ship emergency stop, reversing or encountering wave impact, the stern shaft may bear instantaneous load mutation, and this instantaneous impact force on the static ring is more serious. In terms of thermal load, the friction heat generated by the friction between the dynamic and static rings and the temperature difference effect between seawater and lubricating oil will bring thermal influence to the static ring. Continuous friction heat will cause the temperature of the static ring to rise, while the temperature difference between seawater and lubricating oil may cause thermal stress, further affecting the performance of the static ring. Chemical corrosion is also a big problem faced by the static ring. Due to long-term contact with corrosive components in seawater and lubricating oil, the static ring material is easily eroded, which affects its performance and service life.

[0004]

[0005] ​Traditional inorganic static ring materials such as graphite, ceramics and metals have poor toughness and impact resistance. Under the working condition of vibration and impact of the stern shaft of a ship, the static ring is easy to collide with the dynamic ring material, causing damage. Brittle failure is one of the common problems. When the traditional brittle static ring material is impacted, micro-cracks are easy to expand, and in severe cases, the whole may even be broken, so that the sealing device loses its function. The static ring of a single high polymer material has strong lubricating performance and impact resistance, but it has poor adaptability to extreme working conditions. High temperature failure is more prominent. On the one hand, there is a difference in the thermal expansion coefficient of different materials, which will cause thermal deformation mismatch, resulting in a decrease in the static ring end surface fitting degree, and then warping, causing leakage of the friction pair. On the other hand, when the temperature exceeds 100℃, the lubricating liquid film may vaporize, destroying the stability of the sealing interface and affecting the sealing effect. In addition, the high polymer material may soften or oxidize in a high temperature environment, causing a decrease in hardness and accelerated wear, and the material performance gradually degrades. SUMMARY

[0006] Therefore, the present application provides a fiber-reinforced composite material static ring and a preparation method thereof. The fiber-reinforced composite material static ring prepared by the present application can solve the problem of maintaining high reliability of the static ring material under complex working conditions such as high speed, boundary lubrication, impact and vibration, and avoid the problem of causing sealing leakage due to malignant damage.

[0007] The present application provides a preparation method of a fiber-reinforced composite material static ring, comprising the following steps:

[0008] (A) Preparation of covered yarn:

[0009] The aramid fiber and nylon fiber are compounded and twisted to form a core line, and then cotton and linen fibers are coated on the surface of the core line to obtain a covered yarn;

[0010] (B) Weaving of the strip material:

[0011] The covered yarn is woven into a strip material by a shuttle weaving process;

[0012] (C) Preparation of the prepreg:

[0013] The strip material obtained in step (B) is impregnated with a glue solution, and then dried to obtain a prepreg:

[0014] The glue solution comprises the following components in a mass ratio:

[0015] Phenolic resin 50%~60%;

[0016] Thermal conductive filler 10%~15%;

[0017] Self-lubricating component 1.0%~2.0%;

[0018] Reinforcing filler 1%~3%;

[0019] Interface coupling agent 0.3%~1.5%;

[0020] Solvent balance;

[0021] (D) forming:

[0022] The pre-preg obtained in step (C) is wound on a ring mold to form a ring-shaped sample; then, the ring-shaped sample is placed in a mold for mold curing to obtain a fiber-reinforced composite static ring.

[0023] Preferably, in step (A):

[0024] The linear density of the aramid fiber is 200~800D;

[0025] The linear density of the nylon fiber is 800~1400D;

[0026] The linear density of the core wire is 1000~2200D;

[0027] The mass ratio of the aramid fiber and the nylon fiber is (0.3~1)∶1.

[0028] Preferably, in step (A):

[0029] The process of composite twisting preferably specifically includes: adding Z-direction twist to the aramid fiber, adding Z-direction twist to the nylon fiber, then twisting the aramid and nylon fibers together and applying S-direction twist to obtain the core wire;

[0030] Wherein, the twist when adding Z-direction twist to the aramid fiber is 100~300Z, the twist when adding Z-direction twist to the nylon fiber is 50~300Z, and the twist of the S-direction twist is 100~250S.

[0031] Preferably, in step (A):

[0032] The cotton and linen fiber is a cotton bar collected from natural cotton and linen short fibers, the average length of the single fiber is 25~33mm, and the average diameter of the collected cotton bar is 4~8mm;

[0033] The mass ratio of the cotton and linen fiber to the core wire is (3.5~6)∶1.

[0034] Preferably, in step (B):

[0035] The width of the tape is 50~200mm;

[0036] The weaving process uses the covering yarn as the warp and the nylon yarn as the weft; wherein, the linear density is 800D; the warp density is 8~15 roots / cm, and the weft density is 1~2 roots / cm.

[0037] Preferably, in step (C), the step of impregnating is performed by using a continuous prepreg production equipment.

[0038] The heat-conducting filler is at least one of alumina, zinc oxide and dolomite;

[0039] The self-lubricating component is at least one of graphite and polytetrafluoroethylene;

[0040] The reinforcing filler is at least one of carbon nanotubes and aramid short fibers;

[0041] The interface coupling agent is KH-550;

[0042] The solvent is at least one of ethanol, methanol, acetone and ethylene glycol.

[0043] Preferably, in step (C), the step of impregnating is performed by using a continuous prepreg production equipment.

[0044] The prepreg production equipment comprises an unwinding device, a tension control device, a glue tank, a drying channel and a winding device.

[0045] The process of impregnating comprises the following steps: the tape obtained in step (B) is guided out from the unwinding device, the tension control device gives the tape a tension, the tape enters one end of the glue tank at a set speed, and the tape is impregnated with glue in the glue tank.

[0046] Preferably, the tension given to the tape by the tension control device is 80-150 N, and the set speed is 2-5 m / min.

[0047] The drying temperature is 120-140℃, and the drying time is 15-20 min.

[0048] Preferably, in step (D), the winding tension of the winding forming is 150-300 N.

[0049] Preferably, in step (D), the heating temperature of the solidification forming is 150-180℃, the pressure is 5-10 MPa, and the time is 10-20 h.

[0050] The application further provides a fiber-reinforced composite static ring prepared by the preparation method.

[0051] In view of the problem that the traditional static ring material is prone to failure under complex working conditions and is difficult to meet the high reliability requirement of the ship stern shaft sealing device, the present application makes improvements in many aspects. The preparation method provided by the present application first starts from the basic fiber raw material, prepares a twisted core line through composite twisting, and then coats cotton and hemp fibers on the outer layer of the core line by using ring spinning process, so as to obtain a multi-level structure skeleton fiber with organic blended long fibers in the inner layer and short fiber coated cotton and hemp fibers in the outer layer. Then, a glue solution containing a matrix resin, a plurality of functional fillers and an interface coupling agent is prepared, and the skeleton fiber is fully immersed therein, so that the components can be tightly combined and the synergistic effect can be achieved. The skeleton fiber after immersion is dried to become a prepreg fiber, which is ready for subsequent weaving. The prepreg fiber is woven into a narrow band by using the weaving process, and the weaving structure and density are flexibly adjusted to realize accurate design and control of the structure of the skeleton fiber, so as to meet the specific requirements of the static ring material performance under different working conditions. The woven prepreg narrow band is wound on a ring mold to form a ring-shaped sample, and finally cured into a final product under high temperature and high pressure. During the winding and molding process, the density of the static ring material can be accurately controlled in the range of 1.5-1.7 g / cm3, which not only ensures that the material has sufficient strength and toughness to cope with complex mechanical loads, but also makes the material have a certain porosity, which can quickly guide water and drain water during the friction sealing process, effectively solving the problems of sealing caused by water accumulation and performance degradation of the material.

[0052] The test results show that the impact strength of the product obtained by the present application is above 75 MPa, the compression strength is above 120 MPa, the water absorption is above 2.7%, and the linear expansion coefficient is above 11*10 -5 The friction coefficient is below 0.21, which shows excellent mechanical properties, high water absorption and friction resistance, and ensures the performance requirements of the ship stern shaft sealing friction pair. BRIEF DESCRIPTION OF DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0054] Figure 1 The structure diagram of the sealing composed of the static ring and the dynamic ring;

[0055] Figure 2 The schematic diagram of the coated yarn multi-level structure skeleton fiber obtained in step (A) in the preparation method of the present application. DETAILED DESCRIPTION

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application.

[0057] In the description herein, the technical features described in an open way include both the closed technical solution consisting of the listed features and the open technical solution comprising the listed features.

[0058] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0059] In the description herein, with respect to numerical intervals, unless otherwise specified, the numerical intervals are considered to be continuous, and include the minimum and maximum values of the range, as well as every value between the minimum and maximum values. Further, when ranges are provided for integers, every integer between the minimum and maximum values is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein are to be understood to include any and all sub-ranges subsumed therein.

[0060] In the description herein, with respect to units of data, if only the right end point is provided with a unit, it means that the units of the left end point and the right end point are the same. For example, 50~200mm means that the units of the left end point "50" and the right end point "200" are both mm.

[0061] In a first aspect, the application provides a method for preparing a fiber-reinforced composite static ring, comprising the following steps:

[0062] (A) preparing a covered yarn:

[0063] The aramid fibers and nylon fibers are combined and twisted to form a core yarn, and then cotton and linen fibers are wrapped around the surface of the core yarn to obtain a covered yarn;

[0064] (B) weaving a tape:

[0065] The covered yarn is woven into a tape by a weaving process;

[0066] (C) preparing a prepreg:

[0067] The tape obtained in step (B) is impregnated with a glue solution, and then dried to obtain a prepreg:

[0068] The glue solution comprises the following components in the following mass ratio:

[0069] Phenolic resin 50%~60%;

[0070] Thermal conductive filler 10%~15%;

[0071] Self-lubricating component 1.0%~2.0%;

[0072] Reinforcing filler 1%~3%;

[0073] Interface coupling agent 0.3%~1.5%;

[0074] Solvent balance;

[0075] (D) forming:

[0076] The prepreg obtained in step (C) is wound on a ring mold to form a ring-shaped sample, and then the ring-shaped sample is placed in a mold for mold curing to form a fiber-reinforced composite static ring.

[0077] Under the complex and harsh working conditions of the stern shaft sealing device of the ship, the traditional inorganic and high molecular static ring materials have exposed many problems, and under the working conditions of high speed, boundary lubrication, impact and vibration, it is difficult to maintain high reliability, and it is easy to cause malignant damage, causing sealing leakage, which seriously affects the normal operation of the ship propulsion system. The present application provides a design and forming process of a new type of composite structure static ring material, which has good wear resistance, impact resistance and high temperature resistance, to solve the above problems, and provides a static ring solution with better performance and higher stability for the stern shaft sealing device of the ship.

[0078] Regarding step (A) :

[0079] (A) Preparation of covered yarn: the aramid fiber and nylon fiber are compounded and twisted to form a core line, and then cotton and linen fibers are coated on the surface of the core line to obtain a covered yarn.

[0080] According to the present application, two different fibers are compounded and twisted to form a core line.

[0081] In the present application, the linear density of the aramid fiber (i.e. aramid filament) is preferably 200~800D, and can be 200D, 250D, 300D, 350D, 400D, 450D, 500D, 550D, 600D, 650D, 700D, 750D or 800D.

[0082] In the present application, the linear density of the nylon fiber (i.e. nylon filament) is preferably 800~1400D, and can be 800D, 840D, 900D, 950D, 1000D, 1050D, 1100D, 1150D, 1200D, 1260D, 1300D, 1350D or 1400D.

[0083] In the present application, the ratio of linear density of the nylon fiber and aramid fiber is preferably (1-8):1, and can be specifically 1.05:1, 2:1, 3:1, 3.15:1, 4:1, 5:1, 6:1, 7:1, 8:1. In some embodiments of the present application, the combination of nylon fiber and aramid fiber is as follows: nylon fiber 1260D / aramid fiber 400D, or nylon fiber 840D / aramid fiber 800D, or nylon fiber 1400D / aramid fiber 200D, etc.

[0084] In the present application, the linear density of the obtained core wire is preferably 1000-2200D, and can be specifically 1000D, 1100D, 1200D, 1300D, 1400D, 1500D, 1600D, and more preferably 1600D.

[0085] In the present application, the composite twisting (also known as twisted composite) refers to winding two different fibers (in the present application, aramid fiber and nylon fiber) through a twisting device to form a yarn. In the present application, the process of composite twisting preferably specifically includes: adding Z-direction twist to aramid fiber, adding Z-direction twist to nylon fiber, then twisting aramid and nylon fibers together and applying S-direction twist to obtain a core wire; the above twisting process makes the two fibers combine into a composite structure fiber. In the present application, when adding Z-direction twist to aramid fiber, the twist is preferably 100-300Z, specifically 100Z, 110Z, 120Z, 130Z, 140Z, 150Z, 160Z, 170Z, 180Z, 190Z, 200Z, 210Z, 220Z, 230Z, 240Z, 250Z, 260Z, 270Z, 280Z, 290Z, 300Z, and more preferably 200Z. In the present application, when adding Z-direction twist to nylon fiber, the twist is preferably 50-300Z, specifically 50Z, 60Z, 70Z, 80Z, 90Z, 100Z, 110Z, 120Z, 130Z, 140Z, 150Z, 160Z, 170Z, 180Z, 190Z, 200Z, 210Z, 220Z, 230Z, 240Z, 250Z, 260Z, 270Z, 280Z, 290Z, 300Z, and more preferably 200Z. In the present application, the S-direction twist is preferably 100-250S, specifically 100S, 110S, 120S, 130S, 140S, 150S, 160S, 170S, 180S, 190S, 200S, 210S, 220S, 230S, 240S, 250S, and more preferably 150S. The twist refers to the number of twists per unit length of yarn, i.e. the number of turns per unit length of yarn; in the present application, the unit length is 1 m, and 200Z for example refers to 200Z / m. Z and S represent the twist direction, which refers to the tilt of the spiral line formed by the unit of the yarn sliver rotating around the sliver axis when the yarn is in the vertical position (i.e. the spiral line direction of the fiber / yarn sliver), which is generally divided into Z-direction and S-direction, and 200Z for example refers to the number of twists per unit length of 1 m of yarn along the Z-direction.

[0086] In the present application, the mass ratio of aramid fiber and nylon fiber is preferably (0.3-1):1, specifically 0.3:1, 0.32:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1.0:1. The use of nylon / aramid composite structure in the present application can ensure that the core wire has sufficient strength and flexibility to meet the subsequent process and actual use requirements.

[0087] According to the present application, after the core wire is prepared, cotton and linen fibers are coated on the surface of the core wire.

[0088] In the present application, the cotton and hemp fibers are short fibers of natural cotton and hemp gathered into a cotton bar, the average length of which is preferably 25-33 mm, and can be 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 31 mm, 32 mm or 33 mm; the average diameter of the gathered cotton bar is preferably 4-8 mm, and can be 4 mm, 5 mm, 6 mm, 7 mm or 8 mm.

[0089] In the present application, the cotton and hemp fibers are coated on the surface of the core wire by using a ring spinning equipment. The present application precisely controls the coating ratio, and specifically, the mass ratio of the cotton and hemp fibers to the core wire is preferably (3.5-6) : 1, and can be 3.5:1, 4.0:1, 4.5:1, 5.0:1, 5.5:1 or 6.0:1.

[0090] In the present application, the cotton and hemp fibers are coated on the outer layer of the twisted core wire to form a coated yarn with an inner layer of organic blended long fibers and an outer layer of short fiber coated cotton and hemp fibers, which is a multi-level structure skeleton fiber, based on which subsequent preparation is carried out. The prepared multi-level structure skeleton fiber is as shown in the following figure. Figure 2

[0091] In the present application, a fiber reinforced composite material structure is adopted in material design; wherein, the skeleton fiber adopts a multi-level composite structure, which combines high strength, high toughness, wear resistance, self-lubrication and other excellent properties. Such a composite structure fiber allows different fibers with different properties to work together through the design of composition and ratio. For example, the specific composite structure fiber of the present application combines the advantages of aramid fiber high strength and high temperature resistance, nylon fiber high toughness and self-lubrication, and natural cotton and hemp fiber moisture dissipation and strong bonding with resin. Such a combination makes the skeleton fiber perform well in terms of high temperature resistance, impact resistance and self-lubrication, and provides a solid foundation support for the static ring material.

[0092] Regarding step (B) :

[0093] (B) Weaving the coated yarn into a belt material by using a weaving process.

[0094] In the present application, the belt material is preferably a narrow belt with a width of 50-200 mm, and can be 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, 130 mm, 140 mm, 150 mm, 160 mm, 170 mm, 180 mm, 190 mm or 200 mm. The width of the narrow belt is determined by the axial width of the final product, and is controlled to be 1.2-1.3 times the axial length of the static ring; for example, a skeleton fiber narrow belt with a width of 120-130 mm after being dipped in glue and molded into a product, the axial length of the final static ring product can be about 100 mm.

[0095] ​In the present application, preferably, the cover yarn is used as the warp, the nylon yarn is used as the weft, and the tape is woven by the over-shuttle weaving process.

[0096] In the present application, in the weaving process, the warp and weft densities are mainly controlled, wherein the warp density is preferably 8-15 roots / cm, and specifically can be 8 roots / cm, 9 roots / cm, 10 roots / cm, 11 roots / cm, 12 roots / cm, 13 roots / cm, 14 roots / cm or 15 roots / cm; and the weft density is preferably 1-2 roots / cm, and specifically can be 1 root / cm or 2 roots / cm.

[0097] Regarding step (C) :

[0098] (C) Preparing the prepreg: the tape obtained in step (B) is impregnated with a glue solution, and then dried to obtain the prepreg.

[0099] In the present application, the glue solution comprises the following components in the following mass ratio:

[0100] Phenolic resin 50%-60%;

[0101] Thermal conductive filler 10%-15%;

[0102] Self-lubricating component 1.0%-2.0%;

[0103] Reinforcing filler 1%-3%;

[0104] Interface coupling agent 0.3%-1.5%;

[0105] Solvent balance.

[0106] Among them:

[0107] The source of the phenolic resin is not particularly limited, and can be a commercially available product or prepared according to a known method in the art. The content of the phenolic resin is 50%-60%, and specifically can be 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59% or 60%.

[0108] The thermal conductive filler is preferably at least one of alumina, zinc oxide and dolomite. The content of the thermal conductive filler is 10%-15%, and specifically can be 10%, 11%, 12%, 13%, 14% or 15%.

[0109] The self-lubricating component is preferably at least one of graphite and polytetrafluoroethylene. The content of the self-lubricating component is 1.0% to 2.0%, and specifically can be 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%.

[0110] The reinforcing filler is preferably at least one of carbon nanotubes and aramid short fibers. The content of the reinforcing filler is 1% to 3%, and specifically can be 1%, 2%, 3%.

[0111] The interface coupling agent is preferably KH-550, which can enhance the bonding force between the matrix resin and the skeleton fiber and each functional filler. The content of the interface coupling agent is 0.3% to 1.5%, and specifically can be 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%.

[0112] The solvent is preferably at least one of ethanol, methanol, acetone, and ethylene glycol. The amount of the solvent is the balance, i.e., 100%.

[0113] In the present application, the glue solution is preferably prepared by the following preparation method: phenolic resin, heat-conducting filler, self-lubricating component, reinforcing filler, interface coupling agent, and solvent are mixed to obtain a glue solution. The mixing method is not particularly limited, and each material can be uniformly mixed by a conventional mixing method in the art, such as stirring mixing. The stirring speed is preferably 300 to 500 r / min, and specifically can be 300 r / min, 310 r / min, 320 r / min, 330 r / min, 340 r / min, 350 r / min, 360 r / min, 370 r / min, 380 r / min, 390 r / min, 400 r / min, 410 r / min, 420 r / min, 430 r / min, 440 r / min, 450 r / min, 460 r / min, 470 r / min, 480 r / min, 490 r / min, 500 r / min. The stirring time is preferably 15 to 30 min, and specifically can be 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, 21 min, 22 min, 23 min, 24 min, 25 min, 26 min, 27 min, 28 min, 29 min, 30 min.

[0114] In the present application, when the strip obtained in step (B) is impregnated with glue solution, it is preferably carried out using a continuous prepreg production device. The prepreg production device includes a unwinding device, a tension control device, a glue tank, a drying channel and a winding device. The composite fiber narrow strip is located in the unwinding device, first pulled by a lead wire and then passes through the impregnation device, and is wound on the winding device. The pulling force provided by the winding device drags the narrow strip through the impregnation production line. The impregnation process is as follows: the composite fiber woven narrow strip is led out from the unwinding device, the tension control device imparts tension to the narrow strip, the narrow strip enters one end of the glue tank at a set speed, and is impregnated with glue solution in the glue tank. During this period, the narrow strip is extruded by the counter-roller in the glue tank to ensure uniform impregnation. The narrow strip is led out from the other end of the glue tank after impregnation, dried in the drying channel to remove excess solvent and moisture, and prepared into a prepreg narrow strip. The tension imparted to the narrow strip by the tension control device is preferably 80-150 N, and can be 80 N, 90 N, 100 N, 110 N, 120 N, 130 N, 140 N, 150 N, more preferably 100 N. The set speed is preferably 2-5 m / min, and can be 2 m / min, 3 m / min, 4 m / min, 5 m / min. The drying temperature is preferably 120-140 DEG C, and can be 120 DEG C, 125 DEG C, 130 DEG C, 135 DEG C, 140 DEG C. The drying time is adjusted according to the amount of solvent in the fiber and the performance of the drying equipment, and is generally 15-20 minutes, so that the solvent in the prepreg fiber is completely volatilized, the appropriate glue content and drying degree are achieved, and the subsequent weaving process requirements are met. The dried prepreg narrow strip is wound and sealed for storage. In the present application, the glue content of the obtained prepreg after drying is preferably 40%-60%, and can be 40%, 45%, 50%, 55%, 60%.

[0115] The phenolic resin is used as the base resin in the present application, which is modified by introducing other materials, has the properties of high temperature resistance and wear resistance, can still maintain stable performance under high temperature generated by dynamic and static ring friction, is not easy to soften and deform due to high temperature, thereby effectively prolonging the service life of the static ring and ensuring the reliability of the sealing performance. Among them, a variety of functional composite fillers are introduced to give the static ring material more excellent properties. The aluminum oxide, zinc oxide and dolomite heat-conducting fillers provide good heat-conducting ability, can quickly conduct the heat generated by the friction of the static ring, avoid the problem of thermal deformation caused by local high temperature; graphite, polytetrafluoroethylene and the like play a self-lubricating role under harsh working conditions, reduce the friction between the dynamic and static rings, and reduce the degree of wear; the addition of carbon nanotubes and aramid short fibers gives the material high strength and the performance of preventing fatigue crack propagation, so that the material can still maintain the integrity of the structure when facing impact and long-term fatigue load, and the impact resistance and fatigue resistance are improved. Through precise proportioning of the resin, filler and fiber and optimization design of the overall structure of the material, the directional function design of the static ring material is realized, and the diversified performance requirements of the static ring material under complex working conditions are met.

[0116] Regarding step (D) :

[0117] (D) forming: the prepreg obtained in step (C) is wound and formed on a ring mold to form a ring-shaped sample; then, the ring-shaped sample is placed in a mold for mold curing and forming to obtain a fiber-reinforced composite material static ring.

[0118] In the present application, the forming process includes a winding process and a curing forming process.

[0119] The winding process includes winding and forming the prepreg obtained in step (C) on a ring mold to form a ring-shaped sample. In the present application, the winding tension of the winding and forming is preferably 150-300 N, and can be 150 N, 160 N, 170 N, 180 N, 190 N, 200 N, 210 N, 220 N, 230 N, 240 N, 250 N, 260 N, 270 N, 280 N, 290 N, or 300 N. Controlling the tension in the present application is beneficial to ensure the integrity of the product and the performance of the product. If the tension is too large, it may cause fiber breakage or damage to the prepreg. If the tension is too small, it may affect the density and strength of the product. In the present application, the number of winding layers of the winding and forming is calculated from the inner diameter and outer diameter dimensions of the final static ring product, and the number of winding layers = (product outer diameter - product inner diameter) / prepreg tape thickness.

[0120] After the above winding process, curing and forming is performed: the ring-shaped sample is placed in a mold for mold curing and forming. Specifically, the winding and forming ring-shaped sample is placed in a mold, the inner diameter and outer diameter of the ring-shaped sample are constrained by the mold, and the axial direction can be compressed by the mold slider; the mold is placed in a high-temperature flat vulcanizing machine, and the sample is cured and formed under high temperature and high pressure. In the present application, the heating temperature of the curing and forming is preferably 150-180℃, and can be 150℃, 160℃, 170℃, or 180℃. During the curing process, the pressure of the curing and forming (i.e. the axial pressure of the equipment on the sample) is preferably controlled at 5-10 MPa, and can be 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, or 10 MPa; by controlling the above pressure, the density of the static ring material is ensured to be 1.5-1.7 g / cm 3 , achieving the best balance of material strength, toughness and porosity to meet the water guiding and water repelling requirements of the stern shaft sealing device during friction sealing. The curing time is preferably 10-20 h, and can be 10 h, 11 h, 12 h, 13 h, 14 h, 15 h, 16 h, 17 h, 18 h, 19 h, or 20 h. After curing and forming, a fiber-reinforced composite material static ring product is obtained.

[0121] In a second aspect, the present application also provides a fiber reinforced composite static ring prepared by the preparation method.

[0122] In view of the problem that the traditional static ring material is prone to failure under complex working conditions and is difficult to meet the high reliability requirement of the stern shaft sealing device of a ship, the present application makes improvements in many aspects. The preparation method provided by the present application first starts from the basic fiber raw material, prepares a twisted core line by composite twisting, and then coats cotton and hemp fibers on the outer layer of the core line by ring spinning process, so as to obtain a multi-level structure skeleton fiber with organic blended long fibers in the inner layer and short fiber coated cotton and hemp fibers in the outer layer. Then, a glue solution containing a matrix resin, a plurality of functional fillers and an interface coupling agent is prepared, and the skeleton fiber is fully immersed therein, so that the components can be tightly combined and the synergistic effect can be achieved. The skeleton fiber after immersion is dried to become a prepreg fiber, which is ready for subsequent weaving. The prepreg fiber is woven into a narrow band by the weaving process, and the weaving structure and density are flexibly adjusted to realize accurate design and control of the structure of the skeleton fiber, so as to meet the specific requirements of the performance of the static ring material under different working conditions. The woven prepreg narrow band is wound on a ring mold to form a ring-shaped sample, and finally cured into a final product under high temperature and high pressure. During the winding and molding process, the density of the static ring material can be accurately controlled in the range of 1.5-1.7 g / cm3, which not only ensures that the material has sufficient strength and toughness to cope with complex mechanical loads, but also makes the material have a certain porosity, which can quickly guide water and drain water during the friction sealing process, effectively solving the problems of sealing caused by water accumulation and performance degradation of the material.

[0123] The test results show that the impact strength of the product obtained by the present application is above 75 MPa, the compression strength is above 120 MPa, the water absorption is above 2.7%, and the linear expansion coefficient is above 11x10 -5 The friction coefficient is below 0.21, which shows excellent mechanical properties, high water absorption and friction resistance, and ensures the performance requirements of the ship stern shaft sealing friction pair.

[0124] In order to further understand the present application, the preferred embodiments of the present application are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present application, and are not limitations of the claims of the present application.

[0125] Example 1

[0126] (A) Preparation of coated yarn fiber skeleton:

[0127] The aramid fiber is twisted in Z direction, the nylon fiber is twisted in Z direction, then the twisted aramid fiber and nylon fiber are combined and twisted in S direction to form a core thread, then a cotton fiber is coated on the surface of the core thread to obtain a coated yarn.

[0128] wherein:

[0129] Aramid fiber: linear density 400D;

[0130] Nylon fiber: linear density 1260D;

[0131] The mass ratio of the aramid fiber to the nylon fiber is 0.32:1; the linear density of the core thread is 1600D;

[0132] In the process of the combined twisting, the twist of the aramid fiber is 200Z, the twist of the nylon fiber is 200Z, and the twist of the combined twisting is 150S.

[0133] Cotton fiber: cotton sliver collected from natural cotton short fibers, the average length of the single fiber is 30mm, and the average diameter of the collected cotton sliver is 4mm.

[0134] The mass ratio of the cotton fiber to the core thread is 6:1.

[0135] (B) Weaving tape:

[0136] The coated yarn obtained in step (A) is used as the warp, and the 800D nylon yarn is used as the weft to weave a narrow tape with a width of 120mm by using the shuttle weaving process, wherein the density of the warp is 8 roots / cm, and the density of the weft is 1 root / cm.

[0137] (C) Prepreg preparation:

[0138] The narrow tape obtained in step (B) is dipped in a glue solution (the dipping process is as described above), and then dried (temperature 140℃, time 20min) to obtain a prepreg (the glue content is 50%).

[0139] The composition of the glue solution is as follows:

[0140] Phenolic resin 55%;

[0141] Thermal conductive filler (dolomite) 15%;

[0142] Self-lubricating component (graphite) 2.0%;

[0143] Reinforcing filler (carbon nanotube) 1%;

[0144] Interface coupling agent (KH-550 1%;

[0145] Solvent (ethanol) balance.

[0146] (D) Molding:

[0147] The prepreg narrow tape obtained in step (C) was wound on a ring mold and formed into a ring sample with an inner diameter of 280 mm and an outer diameter of 430 mm under a tension of 250 N. The ring sample was molded and cured at 140 ℃ and 5 MPa (the process is as described above) to obtain a static ring product. The axial length of the sample after molding was about 90 mm.

[0148] Example 2

[0149] (A) Preparation of covered yarn fiber skeleton:

[0150] The aramid fiber was given a Z-twist, the nylon fiber was given a Z-twist, and then the twisted aramid and nylon fibers were combined and given an S-twist to form a core thread. Then, the core thread was coated with cotton and hemp fibers to obtain a covered yarn.

[0151] Wherein:

[0152] Aramid fiber: linear density 800D;

[0153] Nylon fiber: linear density 840D;

[0154] The mass ratio of aramid fiber to nylon fiber was 1:1; the linear density of the core thread was 1600D;

[0155] During the combined twisting process, the twist of the aramid fiber was 200Z, the twist of the nylon fiber was 200Z, and the twist of the combined twisting was 150S.

[0156] Cotton and hemp fibers: cotton sliver collected from natural cotton and hemp short fibers, with an average length of 30 mm and an average diameter of 4 mm after collection.

[0157] The mass ratio of cotton and hemp fibers to core thread was 6:1.

[0158] (B) Weaving tape:

[0159] The covered yarn obtained in step (A) was used as the warp, and 800D nylon yarn was used as the weft to weave a narrow tape with a width of 120 mm by a shuttle weaving process. The warp density was 10 roots / cm, and the weft density was 2 roots / cm.

[0160] (C) Preparation of prepreg:

[0161] The narrow tape obtained in step (B) was immersed in a glue solution (the glue dipping process is as described above), and then dried (temperature 140 ℃, time 20 min) to obtain a prepreg (glue content 55%).

[0162] The composition of the glue solution is as follows:

[0163] Phenolic resin 55%;

[0164] Thermal conductive filler (dolomite) 15%;

[0165] Self-lubricating component (graphite) 2.0%;

[0166] Reinforcing filler (carbon nanotube) 1%;

[0167] Interface coupling agent (KH-550 1%;

[0168] Solvent (ethanol) balance.

[0169] (D) Molding:

[0170] The prepreg narrow tape obtained in step (C) is wound on a ring mold for molding, and wound into a ring sample with an inner diameter of 280 mm and an outer diameter of 430 mm under a tension of 300 N. The ring sample is molded and cured into a static ring product under the conditions of 140℃ and 10 MPa (the process is as described above), and the curing time is 12 h. The axial length of the sample after molding is about 90 mm.

[0171] Example 3

[0172] (A) Preparation of covered yarn fiber skeleton:

[0173] The aramid fiber is given a Z-twist, the nylon fiber is given a Z-twist, and then the aramid fiber and the nylon fiber are combined and twisted to give an S-twist to form a core thread. Then, cotton and linen fibers are wrapped on the surface of the core thread to obtain a covered yarn.

[0174] Wherein:

[0175] Aramid fiber: linear density 400D;

[0176] Nylon fiber: linear density 1260D;

[0177] The mass ratio of aramid fiber to nylon fiber is 0.32:1; the linear density of the core thread is 1600D;

[0178] During the combined twisting process, the twist of the aramid fiber is 200Z, the twist of the nylon fiber is 200Z, and the twist of the combined twisting is 150S.

[0179] Cotton and linen fibers: cotton sliver collected from natural cotton and linen short fibers, with an average length of 30 mm for single fibers, and an average diameter of 4 mm for the collected cotton sliver.

[0180] The mass ratio of cotton and linen fibers to core thread is 6:1.

[0181] (B) Weaving tape:

[0182] The covered yarn obtained in step (A) is used as warp, and 800D nylon yarn is used as weft to weave a narrow tape with a width of 120 mm by using a shuttle weaving process. The warp density is 8 strands / cm, and the weft density is 1 strand / cm.

[0183] (C) Preparation of a prepreg:

[0184] The narrow tape obtained in step (B) is immersed in a glue solution (the glue dipping process is as described above), and then dried (temperature 140°C, time 20 min) to obtain a prepreg (glue content 50%).

[0185] The glue solution comprises:

[0186] Phenolic resin 60%;

[0187] Thermal conductive filler (white dolomite) 13%;

[0188] Self-lubricating component (graphite) 2.0%;

[0189] Self-lubricating component (polytetrafluoroethylene) 2.0%;

[0190] Reinforcing filler (carbon nanotube) 2%;

[0191] Interface coupling agent (KH-550 1%;

[0192] Solvent (ethanol) balance.

[0193] (D) Molding:

[0194] The prepreg narrow tape obtained in step (C) is wound on a ring mold to form a ring sample with an inner diameter of 280 mm and an outer diameter of 430 mm under a tension of 250 N. The ring sample is molded and cured under the conditions of 140°C and 5 MPa (the process is as described above), and the curing time is 12 h to obtain a static ring product. The axial length of the sample after molding is about 90 mm.

[0195] Example 4

[0196] The example 1 is implemented, except that the thermal conductive filler white dolomite in the glue solution is replaced by aluminum oxide.

[0197] Example 5

[0198] The example 1 is implemented, except that the self-lubricating component filler graphite in the glue solution is replaced by polytetrafluoroethylene, and the reinforcing filler carbon nanotube is replaced by aramid short-cut fiber.

[0199] Comparative Example 1

[0200] The procedure of Example 1 was followed, except that the aramid fiber was replaced by nylon fiber (with the same specification as the nylon fiber in Example 1), i.e. the core thread material was all nylon fiber.

[0201] Comparative Example 2

[0202] The procedure of Example 1 was followed, except that the nylon fiber was replaced by aramid fiber (with the same specification as the aramid fiber in Example 1), i.e. the core thread material was all aramid fiber.

[0203] Comparative Example 3

[0204] The procedure of Example 1 was followed, except that in the step of preparing the prepreg, the prepreg tackiness was controlled at 70%, and the glue composition was not changed.

[0205] Performance test

[0206] The impact resistance, mechanical strength, water absorption, and friction resistance of the samples of each example and comparative example were tested. The test results are shown in Table 1.

[0207] Compression strength test method: GB / T 1448 "Determination of the Compression Properties of Fiber Reinforced Plastics", the test direction is perpendicular to the sample compression surface.

[0208] Impact strength (IZOD) test method: GB / T1843-2008 "Determination of the Izod Impact Properties of Plastics".

[0209] Water absorption test method: GB / T1034-2008 "Determination of the Water Absorption of Plastics", 72h water absorption test was performed.

[0210] Linear expansion coefficient: reference ISO11359-2-1999 "Plastics - TMA - Part 2: Determination of Linear Thermal Expansion Coefficient and Glass Transition Temperature".

[0211] Friction coefficient test method: GB / T3960-2016 "Plastics - Method of Sliding Friction and Wear Testing".

[0212] Table 1: Performance test results

[0213]

[0214] From the above test results, it can be seen that the impact strength of the products obtained in Examples 1-5 is above 75MPa, the compression strength is above 120MPa, the water absorption is above 2.7%, the linear expansion coefficient is below 11x10 -5 ​The friction coefficient is below 0.21, excellent mechanical properties, high water absorption, and friction resistance are exhibited, and the performance requirements of the ship stern shaft sealing friction pair are ensured. Compared with Example 1, the performance of Comparative Example 1-2 is obviously reduced, which proves that the aramid fiber and nylon fiber are used as the core line to effectively improve the performance of the product. Compared with Example 1, the core line of Comparative Example 1 is replaced by pure nylon fiber, and the impact and compression performance of the material is obviously reduced; the core line of Comparative Example 2 is replaced by pure aramid fiber, the friction coefficient is increased, and at the same time, the high content of aramid fiber causes the material to be difficult to machine, and the product size precision is reduced; and in Comparative Example 3, the gum amount in the prepreg preparation stage is greatly increased, the fiber component content of the final product is less, the resin content is high, the material brittleness is increased, the impact resistance is poor, and the linear expansion coefficient and the friction coefficient are both increased.

[0215] The principles and implementations of the present application are described in the specific examples in this paper, and the above examples are only used to help understand the method of the present application and its core idea, including the best mode, and also enable any person skilled in the art to practice the present application, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for ordinary skilled in the art, without departing from the principles of the present application, some improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application. The scope of the patent protection of the present application is defined by the claims, and can include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the literal expression of the claims, or if they include equivalent structural elements that are not substantially different from the literal expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A method of manufacturing a fiber reinforced composite stationary ring, characterized by, The method comprises the following steps: (A) preparing a wrapped yarn: a core yarn is prepared by compounding and twisting aramid fibers and nylon fibers, and then cotton and linen fibers are wrapped on the surface of the core yarn to obtain a wrapped yarn; the linear density of the aramid fibers is 200-800D; the linear density of the nylon fibers is 800-1400D; the linear density of the core yarn is 1000-2200D; the mass ratio of the aramid fibers to the nylon fibers is (0.3-1) : 1; the process of the compounding and twisting comprises the following steps: adding Z-direction twist to the aramid fibers, adding Z-direction twist to the nylon fibers, then twisting the aramid fibers and the nylon fibers together and adding S-direction twist to obtain the core yarn; wherein the twist of the aramid fibers is 100-300Z, the twist of the nylon fibers is 50-300Z, and the twist of the S-direction is 100-250S; the cotton and linen fibers are cotton slivers collected from natural cotton and linen short fibers, the average length of the single fibers is 25-33mm, and the average diameter of the collected cotton slivers is 4-8mm; the mass ratio of the cotton and linen fibers to the core yarn is (3.5-6) : 1; (B) weaving a tape: the wrapped yarn is woven into a tape by a weaving process; the width of the tape is 50-200mm; the weaving process uses the wrapped yarn as the warp and nylon yarn as the weft; wherein the linear density of the nylon yarn is 800D; the density of the warp is 8-15 strands / cm, and the density of the weft is 1-2 strands / cm; (C) preparing a prepreg: the tape obtained in step (B) is impregnated with a glue solution and then dried to obtain a prepreg: wherein the glue solution comprises the following components in the following mass ratio: phenolic resin 50%-60%; heat-conducting filler 10%-15%; self-lubricating component 1.0%-2.0%; reinforcing filler 1%-3%; interface coupling agent 0.3%-1.5%; solvent balance; the glue content of the prepreg is 40%-60%; (D) forming: the prepreg obtained in step (C) is wound on a ring mold to form a ring-shaped sample; then the ring-shaped sample is placed in a mold for mold pressing and curing to form a fiber-reinforced composite static ring.

2. The production method according to claim 1, characterized by, In step (C): the heat-conducting filler is at least one of aluminum oxide, zinc oxide and dolomite; the self-lubricating component is at least one of graphite and polytetrafluoroethylene; the reinforcing filler is at least one of carbon nanotubes and aramid short fibers; the interface coupling agent is KH-550; the solvent is at least one of ethanol, methanol, acetone and ethylene glycol.

3. The preparation method according to claim 1, characterized in that, In step (C), a continuous prepreg production equipment is used for impregnation; the prepreg production equipment comprises an unwinding device, a tension control device, a glue tank, a drying channel and a winding device; the process of impregnation comprises the following steps: the tape obtained in step (B) is guided out from the unwinding device, the tension control device gives the tape a tension, and the tape enters one end of the glue tank at a set speed and is impregnated with the glue solution in the glue tank; wherein the tension control device gives the tape a tension of 80-150N; and the set speed is 2-5m / min; The drying temperature is 120-140 DEG C, and the time is 15-20 min.

4. The method of claim 1, wherein, In step (D), the winding tension of the winding forming is 150-300 N.

5. The preparation method according to claim 1, characterized in that, In step (D), the heating temperature of the solidification forming is 150-180 DEG C, the pressure is 5-10 MPa, and the time is 10-20 h.

6. A fiber reinforced composite static ring prepared by the method of any one of claims 1-5.

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