Self-lubricating fabric and use thereof

Abstract

The invention discloses a self-lubricating fabric and application thereof, the fabric has a tubular structure, and the fabric at least contains fibers containing fluorine and fibers containing low-melting-point components. The self-lubricating fabric disclosed by the invention has the characteristics of being integrally formed, free from winding, excellent in dimensional stability after being subjected to high temperature and excellent in wear resistance, and can be applied to plastic bearings or gaskets.

Description

Technical Field

[0001] This invention relates to a self-lubricating fabric and its uses. Background Technology

[0002] Currently, self-lubricating bearings on the market possess good wear resistance and high load-bearing capacity, and are widely used. A self-lubricating bearing consists of an inner wear-resistant liner and an outer load-bearing liner. The inner liner is a self-lubricating fabric, typically wound into a cylindrical shape or woven into a tubular fabric on the surface of a mandrel. This fabric is then installed in a mold, and thermoplastic plastic is filled into the mold through injection molding. After cooling, a solid load-bearing layer is formed, and the bearing is demolded to form a self-lubricating sliding bearing.

[0003] However, most self-lubricating fabrics on the market are sheet or strip structures. Sheet or strip fabrics are made into lining materials by winding. During winding, the fabric needs to be wound onto the corresponding mandrel according to the diameter of the bearing. The lead angle and rotation speed also need to be set, which is a complicated process. Moreover, if the winding is not good, the fabric will overlap or the winding will be hollow, which will lead to accelerated damage to the wear-resistant lining layer.

[0004] In response to the numerous problems that arise during the winding process, technicians have researched and developed a tubular fabric woven from fluorine fibers and ordinary fibers.

[0005] For example, Chinese patent CN116638706A discloses a method for manufacturing a sliding bearing and a sliding bearing, which includes a tubular fabric woven from polytetrafluoroethylene fibers. Although this solves the problems of defect rate and insufficient lifespan caused by poor winding, the fabric made of ordinary fibers has high elasticity and poor dimensional stability during the high-temperature and high-pressure injection molding process, resulting in local accumulation under high-pressure injection molding.

[0006] However, in order to solve the problem of high fabric elasticity, technicians use adhesives and other substances to improve the dimensional stability of the fabric. However, this will drastically reduce the air permeability of the fabric surface and prevent the resin from penetrating. This not only affects the self-lubricating performance of the sliding bearing, but also causes the working surface to directly rub against the friction mating surface components, resulting in accelerated wear of the working layer. Summary of the Invention

[0007] The purpose of this invention is to provide a self-lubricating fabric that is integrally formed without wrapping, has excellent dimensional stability after high temperature, and has excellent wear resistance.

[0008] The solution of this invention is as follows: The self-lubricating fabric of this invention has a tubular structure, wherein the fabric contains at least fibers with fluorine components and fibers with low-melting-point components, wherein the low-melting-point components are in a non-molten state. The self-lubricating fabric of this invention has the characteristics of being integrally formed without winding and having a low coefficient of friction.

[0009] The self-lubricating fabric of this invention has a tubular structure, comprising fibers containing at least fluorine and fibers containing a low-melting-point component, wherein the low-melting-point component is in a molten state. Upon high-temperature treatment, this low-melting-point component remains in a molten state, resulting in excellent dimensional stability and uniform porosity. Bearings manufactured by injection molding of this self-lubricating tubular fabric in a mold not only possess excellent wear resistance but also maintain a long service life.

[0010] The beneficial effects of the present invention are: the self-lubricating fabric of the present invention has the characteristics of being integrally formed without winding, having excellent dimensional stability after high temperature, and having excellent wear resistance, and can be applied to plastic bearings or gaskets. Detailed Implementation

[0011] The self-lubricating fabric of the present invention has a tubular structure, wherein the fabric contains at least fibers with fluorine content and fibers with low-melting-point components, the low-melting-point components being in a non-molten state. This tubular structure can be formed by overlapping the two ends of a sheet or strip fabric through thermal bonding, application of adhesive, ultrasonic treatment, high-frequency welding, or sewing; alternatively, it can be formed by spirally winding a sheet or strip fabric along its length and then using an adhesive to form a tubular structure; or it can be an integrally woven tubular structure.

[0012] If the first processing method is used, the thickness of the overlapping part will be too large or it will be offset, resulting in poor adhesion at the overlapping part. In actual use, when there is relative movement such as friction with the mating material, the self-lubricating fabric cannot be evenly stressed. Due to excessive local stress, it will be worn through, affecting the service life of the sliding bearing. If the second processing method is used, a hollow phenomenon will occur during the winding process. When the inner lining fabric is thermoplasticized with resin, the flowing resin will contaminate the working surface. This not only affects the self-lubricating performance of the sliding bearing, but also causes the working surface to directly rub against the friction mating surface, resulting in accelerated wear of the working layer and affecting the long-term stable use of the sliding bearing.

[0013] The tubular structure of this invention is preferably a one-piece woven fabric. This tubular structure refers to a continuous, uninterrupted fabric in the width direction without any seams. The one-piece woven fabric is directly installed in the mold without any further winding steps. After resin injection molding, cooling, and demolding, a sliding bearing is formed. This ensures uniform force distribution on the material during resin curing and frictional movement, further guaranteeing the long-term excellent self-lubricating properties, wear resistance, and stable service life of the self-lubricating fabric.

[0014] The fabric of this invention contains fluorinated fibers. Fluorinated fibers have low surface tension and are difficult to bond with other fibers, thus exhibiting excellent self-lubricating properties. If the fabric does not contain fluorinated fibers, other yarns besides fluorinated fibers do not have self-lubricating properties or have low self-lubricating properties. When they come into contact with the friction pair, they will be worn through in a short time, thereby affecting the service life of the self-lubricating material.

[0015] The fabric of this invention must also contain fibers with low melting point components. These fibers can be 100% low melting point fibers or composite fibers containing low melting point components. When the fibers containing low melting point components are 100% low melting point fibers, the fabric preferably also contains other fibers, i.e., fibers with both low melting point and high melting point components are combined, and more preferably, fibers formed by twisting the two types of fibers together. When the self-lubricating fabric of this invention has not undergone high-temperature treatment, the low melting point components are in a non-molten state.

[0016] The aforementioned composite fibers are preferably core-sheath type composite fibers, island-type composite fibers, side-by-side composite fibers, or orange-segment type composite fibers. Composite fibers allow fibers to exhibit different properties under specific conditions. The low-melting-point components of the composite fiber can melt at lower temperatures, while the high-melting-point components remain stable at higher temperatures, maintaining the strength and rigidity of the fabric and ensuring its durability and stability. The low-melting-point components are thermoplastic fibers, while the high-melting-point components can be either thermoplastic or non-melting fibers. Considering production costs and efficiency, core-sheath type composite fibers are more preferred.

[0017] In the aforementioned composite fibers, the melting point of the high-melting-point component is more than 60°C higher than that of the low-melting-point component. When the fabric is heat-treated, the low-melting-point fiber melts at high temperatures and bonds with its own fiber bundles or surrounding fibers. After cooling, the fibers are firmly bonded together, significantly improving the dimensional stability of the fabric. The high-melting-point fiber, due to its relatively high melting point, can maintain its overall strength and structure by controlling the heating temperature and time, preventing it from softening or melting during heating. If the melting points of the high-melting-point and low-melting-point fibers are close, after heat treatment, if the temperature is too low, the low-melting-point fiber will not melt and solidify; if the temperature is too high, both the high-melting-point and low-melting-point fibers will melt or soften simultaneously, affecting fiber strength, and further impacting the dimensional stability and overall strength of the fabric. This, in turn, affects the wear resistance and service life of the bearings made from it.

[0018] The preferred weight ratio of high-melting-point fibers to low-melting-point fibers in the aforementioned composite fiber is 80 / 20 to 40 / 60. If the weight of high-melting-point fibers is too low, the overall strength and structure of the fibers will be severely damaged after the fabric is heated and cooled, resulting in low fabric strength and poor stability. If the weight of high-melting-point fibers is too high, the melting of low-melting-point fibers will not completely encapsulate the other fibers in the fabric, thus preventing the low-melting-point fiber bundles from bonding sufficiently with the surrounding fibers, further leading to poor dimensional stability of the fabric. Therefore, considering both high strength and good dimensional stability of the fabric, the preferred weight ratio of high-melting-point fibers to low-melting-point fibers in the composite fiber is 70 / 30 to 50 / 50.

[0019] The preferred fluorine fiber content in the fabric of this invention is 5-60% by weight. The fluorine fiber content refers to the ratio of the weight of fluorine fibers to the total weight of the self-lubricating fabric. The principle of self-lubricating materials is to grind fluorine fibers into small pieces, disperse them evenly on the surface of the material, and then continue friction. The small pieces form a fluorine lubricating film, thereby giving the material self-lubricating properties. If the content is too low, the fluorine fibers, after being ground into small pieces, cannot be guaranteed to be completely and evenly dispersed on the entire surface of the material, resulting in poor self-lubrication and wear within a short time. When the fabric is used in bearings, the self-lubricating fabric needs to be resin-impregnated. Due to its low surface energy, fluorine fibers have poor adhesion to the resin. If the content is too high, the content of other fibers with high surface energy will be relatively low, resulting in poor permeability between the fabric and the resin. The amount of resin wetted on the sliding surface will be very small, and the small amount of resin film will wear away quickly. Without a protective film, the exposed fluorine yarns will wear away quickly when the fabric's sliding surface interacts with the friction surfaces, reducing its service life. Considering the self-lubricating properties and abrasion resistance of self-lubricating fabrics, the content of fluorine fiber in self-lubricating fabrics is more preferably 10-50% by weight.

[0020] When the low-melting-point component in the self-lubricating fabric of this invention is in a non-molten state, the resulting fabric exhibits relatively high elasticity in both warp and weft directions. After applying a certain force in the warp and weft directions, its elongation is 10-50%. During the processing of self-lubricating bearings, to prevent significant dimensional elastic changes in the fabric during high-temperature, high-pressure injection molding, the elongation in both warp and weft directions must be controlled within a certain range. Therefore, when the low-melting-point component in the fabric is in a molten state, the elongation after applying a certain force in the warp and weft directions is preferably 1-10%. If the elongation is too low, it indicates that the low-melting-point fiber completely encapsulates and firmly bonds other fibers during melting. When resin is injected, it is difficult for the resin to penetrate the fabric, resulting in a low resin content. The small amount of resin film will wear away quickly, causing the exposed fluorine fibers to wear out rapidly, reducing the service life. If the elongation is too high, the fabric is easily compressed or deformed under high-temperature, high-pressure conditions during resin injection, causing the fabric to accumulate on the inner surface of the bearing, thus affecting the self-lubricating performance of the sliding bearing and reducing its service life.

[0021] The fluorine fibers of this invention possess excellent lubricity, but their strength is low, making them easily worn away under external forces. Therefore, this invention preferably uses twisted yarns, where fluorine fibers are combined with other high-strength fibers with strong resin adhesion to form a single filament. These twisted yarns not only reduce yarn breakage due to friction during fabric formation but also resist breakage under external abrasion. This is because the lubricating film formed by the wear of the fluorine fibers can adhere evenly and quickly to adjacent fibers, and even under external forces, it is not easily separated from the self-lubricating system, thus significantly improving the service life of the self-lubricating material.

[0022] The twist of the aforementioned twisted yarn is preferably 50-500 T / m. If the twist of the yarn is too large, the yarn itself is prone to twisting and tangling during weaving, affecting weaving efficiency and quality, and the surface of the tubular structure is prone to defects. If the twist is too small, the yarn is prone to friction during weaving, forming fuzz and leading to breakage. Moreover, the lubricating layer formed by fluorine fiber cannot be evenly distributed, thus affecting the service life of the material.

[0023] The fluorine fiber material constituting the self-lubricating fabric of the present invention is any one of polyvinylidene fluoride (PVDF), perfluoroethylene propylene (FEP), ethylene-tetrafluoroethylene copolymer (ETFE), polytetrafluoroethylene (PTFE), and polychlorotrifluoroethylene (PCTFE). Fluorine fibers have high self-lubricating properties, excellent chemical resistance, weather resistance, heat resistance, and flame retardancy. The present invention preferably uses polytetrafluoroethylene (PTFE).

[0024] The fluorine fiber of this invention is produced by wet spinning. Compared with fluorine fiber obtained by the film splitting method, which has an uneven polygonal cross-section, the fluorine fiber obtained by wet spinning has a uniform circular cross-section, smaller fineness deviation between filaments, and more uniform mechanical properties, making it very suitable for weaving self-lubricating fabrics. When the fluorine fiber is subjected to external friction, the fluorine fiber on the friction surface undergoes fibrillation, and the resulting fluorine fiber debris can form a uniform and dense fluorine film. Through compression, a uniform fluorine transfer film can be formed on the friction pair surface, realizing the relative movement between the self-lubricating fabric and the friction pair surface under a low coefficient of friction, thereby achieving an oil-free self-lubricating effect.

[0025] In the fabric of this invention, the fibers with high and low melting point components are preferably one or two selected from polyphenylene sulfide fibers, polyamide fibers, polyimide fibers, aromatic polyamide fibers, polyester fibers, etc. The high-melting-point component and the low-melting-point component in the high-melting-point fibers can be the same fiber or different fibers. Considering the dimensional stability and multifunctionality of the fabric, the high-melting-point fiber and the low-melting-point fiber are preferably two different fibers. Considering the dimensional stability and heat resistance of the fabric, polyester fibers are more preferably selected from the high-melting-point fibers.

[0026] In this invention, the basis weight of the self-lubricating fabric when the low-melting-point component is in a non-molten state is 2–200 g / m². 2 If the weight is too low, the fabric will be too thin and soft, with poor abrasion resistance, and will easily break during friction. If it is too high, it will not only increase costs but also hinder resin penetration into the fabric, resulting in low impregnation. The small amount of resin film will wear away quickly with the use of self-lubricating bearings. Without a protective film, the fabric will wear down rapidly when in contact with the friction surfaces, thus reducing its service life. Considering the abrasion resistance of self-lubricating fabrics, a weight of 5–50 g / m² is more preferable. 2 .

[0027] In this invention, the thickness of the self-lubricating fabric when the low-melting-point component is in a non-molten state is preferably 0.2–1.0 mm. If it is too thin, the fabric, as an inner wear-resistant lining, is easily damaged during wear, leading to breakage of the sliding parts and bearing failure. If it is too thick, the self-lubricating fabric undergoes greater compression deformation, resulting in poorer permeability between the self-lubricating fabric and the resin, weakening the resin's protection of the sliding surface, and easily causing accelerated wear of the self-lubricating fabric, thus reducing its service life.

[0028] After high-temperature post-treatment, the low-melting-point components of the self-lubricating fabric of this invention soften and melt, thus bonding firmly with its own fibers or surrounding fibers. Simultaneously, the other fibers in the fabric, due to their higher melting points, maintain the overall fiber strength and structure, and do not soften or melt upon heating. After cooling, the elongation in the warp and weft directions of the fabric decreases significantly, enhancing its dimensional stability and ensuring smooth operation of the plastic bearing during injection molding.

[0029] The present invention will be further illustrated by the following embodiments, but the scope of protection of the present invention is not limited to the embodiments. The physical property parameters in the embodiments are determined by the following methods.

[0030] Melting points of fibers with high and low melting point compositions

[0031] Several yarns were removed from the fabric that had not undergone high-temperature treatment. The yarns weighed more than 10mg. They were identified by color: dark brown yarns were fluorine yarns, and white yarns were yarns made of fibers containing high and low melting point components. The white yarns were picked out, and yarns weighing 1-5mg were taken out. Then, differential scanning calorimetry was used to scan and test the white yarns. The melting points of the high and low melting point fibers were directly obtained from the spectrum.

[0032] The content of fibers with high and low melting points.

[0033] Ten yarns were randomly removed from an untreated fabric. They were identified by color: dark brown yarns were fluorine-containing yarns, and white yarns were yarns composed of fibers containing high and low melting point components. The white yarns were selected, and their cross-sections were photographed using a scanning electron microscope at 100x magnification. The photographs were printed on paper, and the cross-sectional areas S1 (high melting point component) and S2 (low melting point component) of the fibers were calculated using an area meter. The weight ratio of the high melting point fiber was calculated as S1 / (S1+S2)×100%, and the weight ratio of the low melting point fiber was calculated as S2 / (S1+S2)×100%. This process was repeated three times, and the average value was calculated.

[0034] [Fluorine fiber content]

[0035] According to GB / T 2910-2009, the fiber content was tested using a disassembly method. Three different locations on the self-lubricating fabric were sampled, and approximately 1g of each sample was taken for testing. The yarns in the fabric were disassembled one by one and then identified by color. Dark brown yarns were identified as fluorine fibers, while white yarns were identified as yarns containing high and low melting point components. After drying, the yarns were weighed separately: the weight of the fluorine fiber yarn was m1, and the weight of the other fiber yarns was m2. The fluorine fiber content W was calculated using the following formula: W = m1 / (m1 + m2). The average value was calculated from three measurements.

[0036] Twist

[0037] A whole yarn longer than 50cm was removed from an untreated fabric. According to GB / T14345-2008, the twist count of the 50cm length of the composite yarn was tested using a yarn twist meter via the direct counting method. Five sets of samples were tested consecutively, and the average value of the five test results was calculated. The twist of the composite yarn was then obtained using the following formula: Twist = Twist Count × 2.

[0038]

thickness

[0039] According to JIS L 1096-1999 8.5, the test pressure is 23.5 kPa (240 gf / cm). 2 Five different locations were selected on a single layer of the self-lubricating fabric for measurement, and the average value was calculated.

[0040]

Weight

[0041] Using the direct measurement method, measure a 1-meter length of fabric, weigh the fabric, measure at 3 different locations consecutively, take the results of 3 tests, and calculate the average value.

[0042] Elongation

[0043] Samples with a width of 50mm ± 0.5mm and a length of 80mm ± 1mm ​​were taken along the warp and weft directions of the untreated fabric. Using the weight-hanging method, the length direction was marked with L1 at intervals of 50mm. A 100g weight was hung, and after the weight was suspended for 30 seconds, the marked interval L2 was recorded to obtain the elongation of the fabric.

[0044] The fabric was then placed in an oven with a melting point higher than that of the low-melting-point fiber and heated for 20 minutes before cooling. The elongation of the fabric treated with high temperature was then tested using the same method as described above.

[0045] Elongation is a parameter used to characterize the dimensional stability of fabrics. The closer the elongation value is to 0, the better the dimensional stability. The formula for calculating elongation is as follows: Elongation (%) = (L2 - L1) / L1 × 100%.

[0046]

Wearing life

[0047] The test was conducted on a vertical abrasion testing machine. The test method is as follows: Under conditions of temperature 20±2℃ and humidity 65±4%, the high-temperature treated fabric was tightly fixed on the friction table. A hollow metal cylinder was used as the abrasion test head. The abrasion head was ground with sandpaper, and the friction surface was tested using a roughness measuring instrument to ensure that the average surface roughness was below 0.2. The friction load was set to 70MPa, and the test was conducted at a linear speed of 20mm / s. The time taken for the self-lubricating fabric to wear out from the start of the test was recorded, which is the abrasion life.

[0048] Example 1

[0049] A yarn with a twist of 30% by weight of polytetrafluoroethylene filament and 70% by weight of core-sheath composite fiber was twisted together to obtain a twisted yarn with a twist of 300 T / m. The core component of the core-sheath composite fiber is polyester with a melting point of 256°C, and the sheath component is polyester with a melting point of 180°C. The yarn was woven on a warp knitting machine to obtain a one-piece tubular warp-knitted fabric with a diameter of 50 mm. In the obtained warp-knitted fabric, the polyester sheath component is in a non-molten state. The obtained warp-knitted fabric was then placed in an oven at 200°C and heated for 20 minutes. After cooling, a self-lubricating fabric with a molten polyester sheath component was obtained. The physical properties of the self-lubricating fabric of this invention are shown in Table 1.

[0050] Examples 2-7, 9-10

[0051] The preparation process is the same as in Example 1, and the specific formulation and properties are shown in Table 1.

[0052] Example 8

[0053] A self-lubricating fabric with a twist of 30% by weight of polytetrafluoroethylene filament, 40% by weight of polyester filament with a melting point of 256°C, and 30% by weight of polyester filament with a melting point of 180°C was obtained by twisting together the filaments. This twisted yarn with a twist of 300 T / m was then woven on a warp knitting machine to obtain a one-piece tubular warp-knitted fabric with a diameter of 50 mm. The polyester with a melting point of 180°C in the obtained warp-knitted fabric was in a non-molten state. The obtained warp-knitted fabric was then heated in an oven at 200°C for 20 minutes, removed, and cooled to obtain a self-lubricating fabric with the polyester with a melting point of 180°C in a molten state. The physical properties of the self-lubricating fabric of this invention are shown in Table 1.

[0054] Example 11

[0055] A yarn with a twist of 30% by weight of polytetrafluoroethylene filament and 70% by weight of island-type composite fiber was twisted together to obtain a twisted yarn with a twist of 300 T / m. In the island-type composite fiber, the island component is polyester with a melting point of 256°C, and the sea component is polyester with a melting point of 180°C. The yarn was then woven on a warp knitting machine to obtain a one-piece tubular warp-knitted fabric with a diameter of 50 mm. In the obtained warp-knitted fabric, the sea component polyester was in a non-molten state. The obtained warp-knitted fabric was then placed in an oven at 200°C and heated for 20 minutes. After cooling, a self-lubricating fabric with the sea component polyester in a molten state was obtained. The physical properties of the self-lubricating fabric of this invention are shown in Table 1.

[0056] Example 12

[0057] A yarn with a twist of 30% by weight of polytetrafluoroethylene filament and 70% by weight of parallel composite fibers was twisted together to obtain a twisted yarn with a twist of 300 T / m. The high-melting-point component of the parallel composite fibers was nylon (melting point 265℃), and the low-melting-point component was polyester (melting point 180℃). This was then woven on a warp knitting machine to obtain a one-piece tubular warp-knitted fabric with a diameter of 50 mm. The polyester in the obtained warp-knitted fabric was in a non-molten state. The obtained warp-knitted fabric was then heated in an oven at 200℃ for 20 minutes, removed, and cooled to obtain a self-lubricating fabric with the polyester in a molten state. The physical properties of the self-lubricating fabric of this invention are shown in Table 1.

[0058] Example 13

[0059] A yarn with a twist of 30% by weight of polytetrafluoroethylene filament and 70% by weight of core-sheath composite fiber was twisted together to obtain a twisted yarn with a twist of 300 T / m. The core component of the core-sheath composite fiber is polyester with a melting point of 256°C, and the sheath component is polyester with a melting point of 180°C. The yarn was woven on a warp knitting machine to obtain a one-piece tubular weft-knitted fabric with a diameter of 50 mm. In the obtained weft-knitted fabric, the polyester sheath component is in a non-molten state. The obtained weft-knitted fabric was then heated in an oven at 200°C for 20 minutes, removed, and cooled to obtain a self-lubricating fabric with the polyester sheath component in a molten state. The physical properties of the self-lubricating fabric of this invention are shown in Table 1.

[0060] The self-lubricating fabrics prepared in Examples 1 to 13 can be used in sliding bearings.

[0061] Comparative Example 1

[0062] 30% by weight of polytetrafluoroethylene filament and 70% by weight of ordinary polyester filament with a melting point of 256℃ were twisted together to obtain a twisted yarn with a twist of 300T / m. This yarn was then woven on a warp knitting machine to obtain a one-piece tubular warp-knitted fabric with a diameter of 50mm. The properties of this fabric are shown in Table 2. To improve the dimensional stability of the fabric, an adhesive was used to impregnate and pad the fabric. The properties of the set fabric are also shown in Table 2.

[0063] Comparative Example 2

[0064] Yarns made from 100% by weight of core-sheath composite fibers were woven on a warp knitting machine to obtain a one-piece tubular warp-knitted fabric with a diameter of 50 mm. The core component of the core-sheath composite fiber was polyester with a melting point of 256℃, and the sheath component was polyester with a melting point of 180℃. The polyester sheath component in the resulting warp-knitted fabric was in a non-molten state. The resulting warp-knitted fabric was then heated in an oven at 200℃ for 20 minutes, removed, and cooled to obtain a fabric with the polyester sheath component in a molten state. The physical properties of this fabric are shown in Table 2.

[0065] Comparative Example 3

[0066] A yarn with a twist of 30% by weight of polytetrafluoroethylene filament and 70% by weight of core-sheath composite fiber was twisted together to obtain a twisted yarn with a twist of 300 T / m. The core component of the core-sheath composite fiber is polyester fiber with a melting point of 256℃, and the sheath component is polyester fiber with a melting point of 180℃. This was woven on a warp knitting machine to obtain a one-piece, 50mm diameter strip-shaped warp-knitted fabric, in which the polyester sheath component was in a non-molten state. The obtained warp-knitted fabric was then wound onto a mandrel to form a tubular shape, and then heated in an oven at 200℃ for 20 minutes. After cooling, a strip-shaped self-lubricating fabric with the polyester sheath component in a molten state was obtained. The physical properties of this self-lubricating fabric are shown in Table 1.

[0067] Table 1

[0068]

[0069] Table 2

[0070]

[0071] According to the table above,

[0072] (1) As can be seen from Examples 1 and 2, under the same conditions, the weight ratio of the core component fiber to the sheath component fiber in the former core-sheath composite fiber is in a more preferred range. Compared with the latter, the fabric obtained by the former has a lower elongation after high temperature treatment, that is, good dimensional stability and a longer wear life, that is, excellent wear resistance.

[0073] (2) As can be seen from Examples 1 and 3, under the same conditions, the difference between the melting point of the core component and the melting point of the sheath component in the core-sheath composite fiber of the former is within the preferred range. Compared with the latter, the fabric obtained by the former has a low elongation after high temperature treatment, that is, good dimensional stability and long wear life, that is, excellent wear resistance.

[0074] (3) As can be seen from Examples 1 and 4, under the same conditions, the content of polytetrafluoroethylene fiber in the former is within the preferred range. Compared with the latter, the former fabric has a longer wear life, that is, excellent wear resistance.

[0075] (4) As can be seen from Examples 1 and 5, under the same conditions, the twist of the twisted yarn of the polytetrafluoroethylene yarn and the core-sheath composite fiber formed by the former is within the preferred range. Compared with the latter, the former fabric has a longer wear life, that is, excellent wear resistance.

[0076] (5) As can be seen from Examples 1, 6 and 7, under the same conditions, the type of fiber in Example 1 is within the preferred range. Compared with the latter, the wear life of the fabric in Example 1 is longer, that is, the wear resistance is better.

[0077] (6) As can be seen from Examples 1 and 8, under the same conditions, the former is a core-sheath composite fiber and the latter is a fiber with 100% low melting point components, that is, fibers with high and low melting point components are respectively configured. Under the same conditions, the types of high and low melting point fibers in Example 1 are within the preferred range. Compared with the latter, the former fabric has a longer wear life, that is, excellent wear resistance.

[0078] (7) As can be seen from Example 1 and Comparative Example 1, under the same conditions, the latter fabric does not contain fibers with low melting point components. Even after the fabric is processed by adhesive, the bearing of the latter fabric has a shorter wear life time than the former, that is, poor wear resistance.

[0079] (8) As can be seen from Example 1 and Comparative Example 2, under the same conditions, the latter fabric does not contain fluorine fiber. Compared with the former, the latter fabric has a shorter wear life, that is, poor wear resistance.

[0080] (9) As can be seen from Example 1 and Comparative Example 3, under the same conditions, the latter fabric is strip-shaped and does not have a tubular structure. Compared with the former, the wear life of the fabric in the latter is short, that is, the wear resistance is poor.

Claims

1. A self-lubricating fabric, characterized in that: The fabric has a tubular structure and contains at least fibers with fluorine content and fibers with low-melting-point content, wherein the low-melting-point content is in a non-melting state.

2. The self-lubricating fabric according to claim 1, characterized in that: The fiber containing low-melting-point components is a fiber with 100% low-melting-point components.

3. The self-lubricating fabric according to claim 1, characterized in that: The fiber containing low-melting-point components is a composite fiber containing low-melting-point components.

4. The self-lubricating fabric according to claim 3, characterized in that: The composite fiber is a core-sheath type composite fiber, an island type composite fiber, a parallel type composite fiber, or an orange segment type composite fiber.

5. The self-lubricating fabric according to claim 2, characterized in that: The fabric contains other fibers.

6. The self-lubricating fabric according to claim 3 or 4, characterized in that: The melting point of the high-melting-point component of the composite fiber is more than 60°C higher than that of the low-melting-point component.

7. The self-lubricating fabric according to claim 1, characterized in that: The fluorine component in the fiber contains 5-60% by weight.

8. The self-lubricating fabric according to claim 1, characterized in that: The elongation of the fabric in the warp and weft directions is 10-50%.

9. A self-lubricating fabric, characterized in that: The fabric has a tubular structure and contains at least fibers with fluorine content and fibers with low melting point components, wherein the low melting point components are in a molten state.

10. The self-lubricating fabric according to claim 9, characterized in that: The elongation of the fabric in the warp and weft directions is 1 to 10%.

11. The application of the self-lubricating fabric of claim 9 in plastic bearings or gaskets.

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