Preimpregnated fabric liner as well as preparation method and application thereof

Abstract

The invention relates to the technical field of textiles, in particular to a pre-impregnated fabric liner as well as a preparation method and application thereof. The invention provides a preparation method of a pre-impregnated fabric liner, which comprises the following steps of: pre-impregnating first yarns in resin, twisting, taking one part of the first yarns as warp yarns, twisting the other part of the first yarns and second yarns as weft yarns, and weaving a fabric on a weaving machine; and dipping the fabric in modified resin, drying, and pre-curing to obtain the fabric. According to the preparation method of the pre-impregnated fabric liner, the mode that the yarns are pre-impregnated before being used and then twisted is adopted, weaving is conducted through a weft-backed fabric weave structure, and the structural strength of the fabric liner can be greatly improved.

Description

Technical Field

[0001] The invention relates to the field of textile technology, and in particular to a pre-impregnated fabric liner and a preparation method and application thereof. Background Art

[0002] In recent years, with the continuous advancement of aviation technology and the expansion of its fields, various components in aviation systems are facing more stringent working environments and performance requirements. Especially in some parts that rotate or rotate at high frequencies and are accompanied by radial load forces, the demand for self-lubricating PTFE fabric gaskets is becoming more and more urgent. These gaskets not only need to be able to operate under high-frequency conditions, but also need to ensure that the gaskets remain in good condition after continuous long-term work (for example, the gaskets will not be worn out after working for 600 hours) to ensure the stability and accuracy of the system. Such high standards have posed unprecedented challenges to the high temperature resistance, lubrication performance and structural strength of the gasket materials.

[0003] Traditional self-lubricating spherical bearings often encounter significant temperature rise problems when dealing with such extreme working conditions. Due to the heat generated by friction and high-frequency rotation, the instantaneous temperature of these bearings may quickly rise to over 200°C, which will not only seriously affect the lubrication effect, but may also cause the self-lubricating gasket to fail and fall off due to excessive temperature rise, thereby causing system failure. In addition, under the action of high-frequency rotation and radial loading force, the gasket may also tear after long-term operation due to insufficient structural strength, further exacerbating the instability and unreliability of the system. Therefore, the development of a new PTFE fabric gasket that can simultaneously meet the requirements of high temperature resistance, self-lubrication and high strength has become a key technical problem that needs to be solved urgently in the current aviation field. Summary of the invention

[0004] In order to solve the above-mentioned deficiencies in the prior art, the present invention provides a pre-impregnated fabric liner and a preparation method and application thereof.

[0005] A first aspect of the present invention provides a method for preparing a pre-impregnated fabric liner, comprising the following steps:

[0006] The first yarn is pre-impregnated in a resin, and after twisting, a part of the first yarn is used as a warp yarn, and the other part is twisted with the second yarn as a weft yarn, and the fabric is woven on a loom;

[0007] The fabric is impregnated in a modified resin, and then dried, pre-cured and formed to obtain the fabric.

[0008] In one embodiment, the weaving structure of the fabric is a double-weft structure, wherein the surface layer is double twill and the bottom layer is plain weave.

[0009] In one embodiment, the resin comprises: a base resin; a solvent; the modified resin comprises: a base resin; a modified filler; a solvent;

[0010] Preferably, the resin comprises, by weight percentage: 60%-70% of base resin; 30%-40% of solvent;

[0011] Preferably, in terms of weight percentage, the modified resin comprises: 80%-90% of base resin; 3%-15% of modified filler; and 1%-10% of solvent.

[0012] In one embodiment, the matrix resin includes one or a combination of epoxy resin and phenolic resin; and / or

[0013] The modified filler includes one or a combination of any two or more of chopped PTFE fiber, tungsten disulfide, molybdenum disulfide, boron nitride, and silicon carbide; and / or

[0014] The solvent includes one of acetone, ethanol, ethyl acetate, and butanone, or a combination of any two or more thereof.

[0015] In one embodiment, the method for preparing the modified resin comprises the following steps: firstly weighing an appropriate amount of base resin and modified filler for premixing, and then adding a solvent for remixing.

[0016] In one embodiment, the first yarn and the second yarn are made of different materials;

[0017] Preferably, the first yarn is selected from one or a combination of any two or more of polyamide fiber, carbon fiber, Nomex fiber or glass fiber;

[0018] Preferably, the second yarn is selected from PTFE fibers;

[0019] Preferably, the linear density of the first yarn is 250±50D;

[0020] Preferably, the linear density of the second yarn is 250±50D.

[0021] In one embodiment, the pre-impregnation temperature is 80-90° C., and the pre-impregnation speed is 25-40 m / min.

[0022] In one embodiment, the immersion treatment temperature is room temperature, and the immersion treatment time is 0.5-2 minutes; and / or

[0023] The drying temperature is 40-50°C and the drying time is 4-10h; and / or

[0024] The pre-curing temperature is 70-90° C., the pre-curing pressure is 0.5-2 MPa, and the pre-curing time is 0.3-0.8 h.

[0025] The second aspect of the present invention provides a pre-impregnated fabric pad obtained by the preparation method described above.

[0026] A third aspect of the present invention provides a use of the preimpregnated fabric liner as described above in a spherical plain bearing.

[0027] Based on the above, compared with the prior art, the preparation method of the pre-impregnated fabric pad provided by the present invention adopts a method of pre-impregnating the yarn before use and then twisting it, and weaving it with a double-weft fabric structure, which can greatly improve the structural strength of the fabric pad.

[0028] Other features and beneficial effects of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other beneficial effects of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 Photo of the yarn that has been pre-impregnated;

[0031] Figure 2 This is a photo of the yarn that has not been pre-impregnated;

[0032] Figure 3 A photo of a double-weft structure fabric provided in Example 1 of the present invention;

[0033] Figure 4 This is a photograph of the surface state of the spherical plain bearing before the life test in Example 1 of the present invention;

[0034] Figure 5 This is a photo of the surface state of the spherical plain bearing after the life test in Example 1 of the present invention;

[0035] Figure 6 This is a photograph of the surface state of the spherical plain bearing before the life test in Example 2 of the present invention;

[0036] Figure 7 This is a photo of the surface state of the spherical plain bearing after the life test in Example 2 of the present invention;

[0037] Figure 8 This is a photo of the surface state of the spherical plain bearing before the life test in Comparative Example 1 of the present invention;

[0038] Fig. 9 This is a photo of the surface state of the spherical plain bearing after the life test in Comparative Example 1 of the present invention;

[0039] Fig.10 This is a photo of a weft double structure fabric that has not been pre-impregnated;

[0040] Fig.11 This is a photo of the yarn of the double-weft structure fabric that has not been pre-impregnated and has been touched with a sharp object and has been looped;

[0041] Fig.12 This is a photo of the surface state of the spherical plain bearing before the life test in Comparative Example 2 of the present invention;

[0042] Fig.13 This is a photograph of the surface state of the spherical plain bearing after the life test in Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments; the technical features designed in different implementation modes of the present invention described below can be combined with each other as long as they do not conflict with each other; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0044] In the description of the present invention, it should be noted that all terms used in the present invention (including technical terms and scientific terms) have the same meanings as those generally understood by ordinary technicians in the field to which the present invention belongs, and cannot be understood as limitations on the present invention; it should be further understood that the terms used in the present invention should be understood to have the same meanings as these terms in the context of this specification and in the relevant fields, and should not be understood in an idealized or overly formal sense, unless explicitly defined in the present invention.

[0045] An embodiment of the present invention provides a method for preparing a pre-impregnated fabric liner, comprising the following steps:

[0046] Step 1, pre-impregnating the first yarn in a resin;

[0047] Specifically, the first yarn is selected from any one of the following yarns or a mixture thereof: polyamide fiber, carbon fiber, Nomex fiber or glass fiber; the polyamide fiber can be, for example, aliphatic polyamide fiber, aromatic polyamide fiber, mixed polyamide fiber, etc.; preferably, the first yarn is selected from polyamide fiber, which plays a strong supporting role in the load-bearing process of the pad and provides overall strength. Pre-impregnation is used to make the fiber surface hairiness more conformable and the fiber bundling more stronger; in a preferred embodiment of the present invention, the linear density of the first yarn is 250±50D.

[0048] In an embodiment of the present invention, the resin includes: a base resin; a solvent; the base resin is preferably a thermosetting resin, such as an epoxy resin, a phenolic resin, etc. Compared with thermoplastic resins, the use of thermosetting resins can provide higher strength to the material system of the present invention; the solvent includes one of acetone, ethanol, ethyl acetate, and butanone, or a combination of any two or more; preferably, in terms of weight percentage, the resin includes: 60%-70% of the base resin; 30%-40% of the solvent; the present invention improves the surface properties and internal structure of the yarn through pre-impregnation treatment, and this treatment not only makes the hairiness on the surface of the yarn more fitted, reducing the friction and wear caused by the hairiness, but also enhances the overall strength and stability of the yarn by increasing the cohesive force.

[0049] Further, the pre-impregnated yarn (see Figure 1 ) and yarns without pre-impregnation (see Figure 2 ) were used to compare the mechanical properties, and the results are shown in the following table:

[0050] Table 1 Mechanical properties of yarn before and after pre-impregnation treatment - breaking strength data

[0051]

[0052] It can be seen from the data in Table 1 that the average breaking strength of the yarn before and after pre-impregnation increased from 26.958 cN / dtex to 30.623 cN / dtex, and the breaking strength increased by about 13.6%, indicating that the mechanical properties of the yarn were improved after pre-impregnation treatment.

[0053] In a preferred embodiment of the present invention, the temperature of the pre-impregnation treatment is preferably 80-90° C., the speed of the pre-impregnation treatment is 25-40 m / min, and more preferably, the speed of the pre-impregnation treatment is 30-35 m / min.

[0054] In a preferred embodiment of the present invention, drying is performed after pre-impregnation. At this time, the drying temperature is preferably 80-90° C. and the drying line speed is 30-35 m / min.

[0055] Step 2, twisting the first yarn after pre-impregnation, dividing the first yarn after pre-impregnation into two parts, one part of which is used as warp yarn, and the other part is twisted with the second yarn as weft yarn, and weaving the fabric on a loom;

[0056] Specifically, the twisting treatment is preferably performed by twisting a single yarn in the Z direction, with a twist of 150±20 twists / meter; by twisting the first yarn, the friction between the fibers is increased, the fibers are pressed against each other, and are not easy to slide against each other, so that the yarn obtains a certain strength. When an external force acts on the yarn, the tension of all fibers is balanced by the sum of the axial components of the yarn and the external force, and its tangential component makes the yarn tend to rotate, while the normal component makes the fibers hold together more tightly, thereby improving the strength of the yarn: the twisted yarn, due to the increased friction between the fibers, is not easy to fall off when the yarn is worn, thereby improving the wear resistance of the yarn. In a preferred embodiment of the present invention, the warp and weft density parameters of the fabric weaving are as follows: the warp density is 25-35 strands / cm, and the weft density is 20-30 strands / cm;

[0057] In a preferred embodiment of the present invention, the twisting is preferably performed in the Z direction, with a twist of 300±20 twists / m. The first yarn and the second yarn are made of different materials, and different yarns are used to provide different functions or effects: for example, the first yarn provides overall strength, and the second yarn provides overall wear resistance, and the two work together to achieve better friction and wear performance. The present invention can combine the advantages of the two yarns by twisting yarns of different materials, and improve the strength, wear resistance, elasticity and other properties of the fabric. Preferably, the second yarn includes PTFE fiber, and the PTFE fiber is preferably brown. This type of PTFE fiber has a low friction coefficient and is more wear-resistant; in a preferred embodiment of the present invention, the linear density of the second yarn is 250±50D.

[0058] The present invention pre-impregnates, twists, and double-twists the yarns of the wefts, which effectively improves the centripetal force and cohesive force while giving the fabric a higher strength, forming a compact structure that is not easily damaged laterally, improving processability, and improving anti-pilling and anti-snagging properties. After various processes, the pad has a uniform structure, increased strength, reduced strength unevenness, and improved physical properties such as wear resistance, friction, and heat dissipation rate.

[0059] In a preferred embodiment of the present invention, the base resin used in the resin is the same as the base resin used in the modified resin. By directly using the impregnated base resin to pre-impregnate the yarn, the phenomenon of poor sizing impregnation in the later preparation process can also be effectively prevented. In addition, in the embodiment of the present invention, the twisting is performed on the first yarn and the second yarn. The first yarn is first pre-impregnated and then twisted with the second yarn before weaving. This is because the first yarn and the second yarn are interwoven with a specific structure, and can jointly withstand the friction force on the bonding surface and the working surface.

[0060] In a preferred embodiment of the present invention, the weaving structure of the fabric is a double weft structure, with a surface layer of double twill and a bottom layer of plain weave. Specifically, the yarn density of the first yarn and the second yarn used in the present invention is preferably 250±50D. The selection of yarns with this density can effectively ensure that the thickness of the fabric after interweaving is controlled within 0.50-0.70mm. After the warp and weft are interwoven within this thickness range, the chambers and channels formed are sufficiently uniform and abundant. Too high or too low a density directly affects the thickness of the fabric and the amount of glue in the chamber, ultimately limiting the performance and life of the fabric pad.

[0061] The fabric adopts a unique composite structure. The pre-impregnated fabric pad includes a working surface and a bonding surface. The working surface is the part of the fabric pad that directly participates in friction and wear, and the bonding surface is the part of the fabric pad that is bonded to the bearing or other components. In one embodiment of the present invention, the warp yarn and the weft yarn are woven in a double weft structure, and the surface layer (working surface) of the fabric presents a double twill pattern, which can weave a working surface with a high density and a smooth surface, which can effectively reduce friction and withstand high-frequency rotation conditions. Figure 3 The bottom layer (adhesive surface) of the fabric presents a plain weave structure, which has good flatness and high firmness. As an adhesive surface, it can ensure the peel strength of the pad. After the double twill and plain weave are mixed and woven, abundant chambers and channels can be formed, and the chambers and channels are interconnected to form a tightly integrated multi-layer composite. The fusion and interweaving of the above two weaving structures make the interweaving points more, the supporting points more, and the structural chambers more, which is more conducive to storing resin and improving the wettability of the fabric pad.

[0062] Furthermore, the present invention compares the mechanical properties of fabrics with different weaving structures, and the results are shown in the following table:

[0063] Table 2 Mechanical properties of fabrics with different fabric structures - tensile strength data table

[0064]

[0065]

[0066] According to the data in Table 2, it can be seen that the tensile strength in the warp and weft directions of the fabric with a double weft structure is higher than that of the plain weave structure, and the tensile strength in the warp and weft directions is increased by 74.2% and 123.5% respectively, indicating that the double weft weaving structure improves the mechanical properties of the fabric and the structural strength is improved.

[0067] Step 3: The fabric is impregnated in a modified resin, and then dried and pre-cured to obtain the fabric.

[0068] Specifically, the modified resin includes: a base resin; a modified filler; and a solvent. The base resin is preferably a thermosetting resin. Compared with thermoplastics, the use of a thermosetting resin can provide a higher strength to the material system. The present invention uses a thermosetting resin including one or a combination of two of epoxy resin and phenolic resin; the modified filler includes but is not limited to short-cut PTFE fiber, tungsten disulfide (WS2), molybdenum disulfide, boron nitride, silicon carbide, etc. In the resin system, short-cut PTFE fiber and tungsten disulfide can reduce the friction coefficient during the working process. For example, tungsten disulfide is a typical layered compound, and its crystal structure is composed of three layers of sulfur-tungsten-sulfur atomic arrangement. The layers are interconnected by weak van der Waals forces. This weak interlayer bonding makes each atomic layer easy to slip when subjected to external forces, thereby forming a natural lubrication effect. This self-lubricating property makes tungsten disulfide perform well in mechanical systems that require long-term non-lubricated working environments, especially in high-frequency rotation situations; during the friction and wear process, the resin matrix, as the material that initially contacts the grinding surface, often experiences wear and gradually peels off due to its relatively weak wear resistance. This process causes the short-cut polytetrafluoroethylene (PTFE) fibers and tungsten disulfide (WS2) particles originally evenly dispersed in the resin matrix to gradually be exposed to the grinding surface and become the main friction contact body. The short-cut PTFE fibers, with their excellent lubrication properties and wear resistance, and the tungsten disulfide particles, with their unique layered structure and excellent self-lubricating properties, jointly show a significant friction reduction effect on the friction interface. This synergistic effect not only effectively reduces the friction coefficient, but also significantly improves the overall wear resistance and friction and wear performance of the liner, thereby ensuring that the fabric liner has good comprehensive performance under complex working conditions. Preferably, the modified resin comprises: 80%-90% base resin; 3%-15% modified filler; 1%-10% solvent; preferably, the temperature of the impregnation treatment is room temperature, which is 20-30°C, and the time of the impregnation treatment is 0.5-2min.

[0069] In a preferred embodiment of the present invention, when a thermosetting resin is used as the matrix resin, if the thermosetting resin is directly cured and formed after drying, the direct curing will result in incomplete curing due to the inability to fully remove the solvent inside the thermosetting resin during the drying process, and the residual solvent will interfere with the curing reaction, so that the resin cannot form a stable three-dimensional grid structure. In addition, the thermosetting resin will shrink in volume during the curing process, thereby generating internal stress. If the curing is performed directly, the internal stress may not be fully released, resulting in cracking, deformation and other problems in the resin product during subsequent use. Therefore, in a preferred embodiment of the present invention, after drying, the fabric pad is placed at a lower temperature for pre-curing so that the stress inside the resin is initially released, which helps to avoid cracking, deformation and other problems caused by excessive internal stress during the final curing process. At the same time, through pre-curing, it can be ensured that the resin is in a relatively stable state before the final curing, which helps to reduce defects in the curing process and improve the curing quality. Preferably, the pre-curing temperature is 70-90°C and the pre-curing time is 0.3-0.8h.

[0070] In a preferred embodiment of the present invention, after drying is completed, the pre-curing also includes pre-pressing to control the thickness of the fabric pad, so that the modified resin attached to the surface of the fabric is more uniform, and the bubbles inside the material can be effectively eliminated, and the surface defects of the fabric pad are reduced, thereby improving the density and quality of the product; preferably, the pre-pressing pressure during the pre-curing process is 0.5-2MPa.

[0071] Preferably, the solvent includes one of acetone, ethanol, ethyl acetate, butanone, or a combination of any two or more thereof.

[0072] In a preferred embodiment of the present invention, the preparation method of the modified resin includes the following steps: first weighing an appropriate amount of base resin and modified filler for premixing, and then adding a solvent for remixing; the addition of the solvent plays a role in controlling the viscosity of the system. If the viscosity of the system is too low, the fluidity of the resin is too high during impregnation, which is difficult to control and results in less resin hanging on the fabric; and if the viscosity is too high, the fluidity becomes poor and the fabric cannot be completely impregnated during impregnation.

[0073] In one embodiment of the present invention, the drying temperature is 40-50° C., and the drying time is 4-10 hours.

[0074] The present invention also provides a pre-impregnated fabric liner prepared by the preparation method described in the above preparation scheme.

[0075] The present invention also provides the use of the pre-impregnated fabric liner described in the above technical solution on a spherical bearing.

[0076] The following examples and comparative examples are used to illustrate the present invention in more detail, but are not intended to limit the present invention in any way. In addition, unless otherwise specified, the raw materials used may also be conventional commercial products in the art, or may be prepared by conventional methods in the art.

[0077] Example 1

[0078] 253D polyamide yarn and 248D PTFE yarn are selected as weaving raw materials. The polyamide yarn is pre-impregnated in a resin at a temperature of 85°C and a speed of 30 m / min. The resin is composed of 68% epoxy resin and 32% acetone.

[0079] The warp yarn is formed by back-twisting pre-impregnated polyamide yarn with a twist of 170 twists / m; the weft yarn is formed by back-twisting pre-impregnated polyamide yarn and PTFE yarn with a twist of 300 twists / m.

[0080] The fabric is woven with a double weft structure, refer to Figure 3 As shown, the warp density is 30 strands / cm, the weft density is 24 strands / cm, the weaving process is smooth, the yarn hairiness is flat after sizing, and the fabric surface is flat. The fabric is impregnated in the modified resin at room temperature (25°C), dried and pre-cured. The drying conditions are 45°C and 5h, and the pre-curing conditions are 70°C, 1.0MPa, and 0.8h. The modified resin includes 5% chopped PTFE fiber, 5% tungsten disulfide powder, 85% epoxy resin and 5% ethanol (solvent name) to obtain a liner. The liner is pasted and cured (curing conditions are 165°C, 0.6MPa, 30min) in an extruded stainless steel spherical bearing (model GEFZ25DE1T).

[0081] The spherical bearing was operated for 600 hours under high-frequency rotation conditions (at room temperature, force value 10.23 kN, frequency 300 times / min, swing angle ±10°, cyclic swing, and the specific working conditions are shown in Table 3). The liner was not worn out and met the use requirements. The specific wear amount is shown in Table 4 below. The bearings before and after the experiment are shown in Table 4. Figure 4 , Figure 5 .

[0082] Table 3

[0083] Force 0 +10.23kN 0 -10.23kN 0 Swing angle +10° 0° -10° 0° +10°

[0084] Table 4

[0085] Duration of the test Wear 300h 0.039mm 500h 0.082mm 600h 0.115mm, not worn through

[0086] Example 2

[0087] 258D polyamide yarn and 249D PTFE yarn were selected as weaving raw materials. The polyamide yarn was pre-impregnated in a resin at 85° C. at a speed of 33 m / min. The resin consisted of 70% epoxy resin and 30% acetone.

[0088] The warp yarn is formed by backhand twisting of pre-impregnated polyamide yarn, with a twist of 170 twists / m; the weft yarn is formed by backhand twisting of pre-impregnated polyamide yarn and PTFE yarn, with a twist of 300 twists / m.

[0089] The fabric is woven with a double weft structure, refer to Figure 3 As shown, the warp density is 31 strands / cm and the weft density is 21 strands / cm. After the fabric is impregnated in the modified resin at room temperature (25°C), it is dried and pre-cured. The drying conditions are 40°C and 10 hours, and the pre-curing conditions are 80°C, 0.8MPa, and 0.6 hours. The modified resin includes 82% epoxy resin, 4% short PTFE fiber, 4% tungsten disulfide powder, 2% molybdenum disulfide powder and 8% acetone to obtain a liner. The liner is pasted and cured (curing conditions are 165°C, 0.5MPa, 45min) in an extruded stainless steel spherical bearing (model GEFZ25DE1T).

[0090] The spherical bearing was operated for 600 hours under high-frequency rotation conditions (at room temperature, force value 10.23 kN, frequency 300 times / min, swing angle ±10°, cyclic swing, and the specific working conditions are shown in Table 3). The liner was not worn out and met the use requirements. The specific wear amount is shown in Table 5 below. The bearings before and after the experiment are shown in Table 5. Figure 6 , Figure 7 .

[0091] Table 5

[0092] Duration of the test Wear 300h 0.051mm 500h 0.093mm 600h 0.120mm, not worn through

[0093] Comparative Example 1

[0094] The difference between Comparative Example 2 and Example 2 is that a plain weave structure is used for weaving.

[0095] 258D polyamide yarn and 249D PTFE yarn were selected as weaving raw materials. The polyamide yarn was pre-impregnated in a resin at 85° C. at a speed of 33 m / min. The resin consisted of 70% epoxy resin and 30% acetone.

[0096] The warp yarn is formed by backhand twisting of pre-impregnated polyamide yarn, with a twist of 170 twists / m; the weft yarn is formed by backhand twisting of pre-impregnated polyamide yarn and PTFE yarn, with a twist of 300 twists / m.

[0097] The fabric is woven with a plain weave structure, with a warp density of 30 strands / cm and a weft density of 21 strands / cm. The fabric is impregnated in a modified resin at room temperature (25°C), dried, and pre-cured. The drying conditions are 40°C and 10 hours, and the pre-curing conditions are 80°C, 0.8MPa, and 0.6 hours. The modified resin includes 82% epoxy resin, 4% short PTFE fiber, 4% tungsten disulfide powder, 2% molybdenum disulfide powder, and 8% acetone to obtain a liner. The liner is pasted and cured (curing conditions are 165°C, 0.5MPa, 45min) in an extruded stainless steel spherical bearing (model GEFZ25DE1T).

[0098] The spherical bearing was operated for 500 hours under high-frequency rotation conditions (at room temperature, force value 10.23 kN, frequency 300 times / min, swing angle ±10°, cyclic swing, and the specific working conditions are shown in Table 3). The bearing was worn out, the liner was extruded and peeled off, and it failed to meet the use requirements. The specific wear amount is shown in Table 6 below. The bearings before and after the experiment are shown in Table 6. Figure 8 , Fig. 9 .in, Fig. 9 The left side shows the main wear position of the sample after working for 500 hours, and the right side shows the broken liner extruded from the sample after working for 500 hours.

[0099] Table 6

[0100] Duration of the test Wear 300h 0.109mm 500h Liner extrusion, peeling 600h -

[0101] Comparative Example 2

[0102] The difference between Comparative Example 2 and Example 1 / Example 2 is that no pre-impregnation treatment was performed.

[0103] 247D polyamide yarn and 259D PTFE yarn were selected as weaving raw materials and were directly woven without pre-impregnation treatment.

[0104] The warp yarn is made of polyamide yarn twisted backhand with a twist of 170 twists / m; the weft yarn is made of polyamide yarn and PTFE yarn twisted backhand with a twist of 300 twists / m.

[0105] The fabric is woven with a double weft structure, with a warp density of 30 strands / cm and a weft density of 21 strands / cm. The weaving process often causes yarn breakage, serious yarn scattering, and weaving difficulties. The woven fabric has many surface defects, the yarns are loose and not tight enough, the yarns are looped, and the surface quality is poor. Fig.10 , Fig.11 ( Fig.11 is to touch the looped yarn with a sharp object).

[0106] After the fabric is impregnated in the modified resin at room temperature (25°C), it is dried and pre-cured, the drying conditions are 40°C, 10 hours, and the pre-curing conditions are 80°C, 0.8MPa, 0.6 hours, the modified resin includes 82% epoxy resin, 4% short PTFE fiber, 4% tungsten disulfide powder, 2% molybdenum disulfide powder and 8% acetone, to obtain a liner. The liner is pasted and cured (curing conditions are 165°C, 0.5MPa, 45min) in an extruded stainless steel spherical bearing (model GEFZ25DE1T).

[0107] The spherical bearing was operated for 100 hours under high-frequency rotation conditions (at room temperature, force value 10.23 kN, frequency 300 times / min, swing angle ±10°, cyclic swing, and the specific working conditions are shown in Table 3). The bearing was worn out, the liner was broken and squeezed out, and it failed to meet the use requirements. The specific wear amount is shown in Table 7 below. The bearings before and after the experiment are shown in Table 7. Fig.12 , Fig.13 .

[0108] Table 7

[0109] Duration of the test Wear 100h Liner broken, extruded and falling off 300h - 500h - 600h -

[0110] It can be seen that the preparation method of the pre-impregnated fabric pad provided by the present invention adopts a method of pre-impregnating the yarn with resin before use and then twisting it, and weaving it with a double-weft fabric structure, which can greatly improve the structural strength of the fabric pad.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a pre-impregnated fabric liner, characterized in that: The following steps are involved: The first yarn is pre-impregnated in a resin, and after twisting, a part of the first yarn is used as a warp yarn, and the other part is twisted with the second yarn as a weft yarn, and the fabric is woven on a loom; The fabric is impregnated in the modified resin, and then dried and pre-cured to obtain the fabric.

2. The preparation method according to claim 1, characterized in that: The weaving structure of the fabric is a double-weft structure, wherein the surface layer is double twill and the bottom layer is plain weave.

3. The preparation method according to claim 1, characterized in that: The resin comprises: a base resin; a solvent; The modified resin comprises: a base resin; a modified filler; a solvent; Preferably, the resin comprises, by weight percentage: 60%-70% of base resin; 30%-40% of solvent; Preferably, in terms of weight percentage, the modified resin comprises: 80%-90% of base resin; 3%-15% of modified filler; and 1%-10% of solvent.

4. The preparation method according to claim 3, characterized in that: The matrix resin includes one or a combination of epoxy resin and phenolic resin; and / or The modified filler includes one or a combination of any two or more of chopped PTFE fiber, tungsten disulfide, molybdenum disulfide, boron nitride, and silicon carbide; and / or The solvent includes one of acetone, ethanol, ethyl acetate, and butanone, or a combination of any two or more thereof.

5. The preparation method according to claim 3, characterized in that: The preparation method of the modified resin comprises the following steps: firstly weighing an appropriate amount of base resin and modified filler for premixing, and then adding a solvent for remixing.

6. The preparation method according to claim 1, characterized in that: The first yarn and the second yarn are made of different materials; Preferably, the first yarn is selected from one or a combination of any two or more of polyamide fiber, carbon fiber, Nomex fiber or glass fiber; Preferably, the second yarn is selected from PTFE fibers; Preferably, the linear density of the first yarn is 250±50D; Preferably, the linear density of the second yarn is 250±50D.

7. The preparation method according to claim 1, characterized in that: The pre-impregnation temperature is 80-90° C., and the pre-impregnation speed is 25-40 m / min.

8. The preparation method according to claim 1, characterized in that: The temperature of the immersion treatment is room temperature, and the time of the immersion treatment is 0.5-2 minutes; and / or The drying temperature is 40-50°C and the drying time is 4-10h; and / or The pre-curing temperature is 70-90° C., the pre-curing pressure is 0.5-2 MPa, and the pre-curing time is 0.3-0.8 h.

9. A pre-impregnated fabric pad prepared according to the preparation method according to any one of claims 1 to 8.

10. Use of the preimpregnated fabric liner according to claim 9 in a spherical bearing.

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