Self-lubricating composite belt and preparation method thereof

Abstract

The invention discloses a preparation method of a self-lubricating composite belt, and belongs to the technical field of transmission conveying belts and running belts. Weaving base cloth by adopting a herringbone weaving method, weaving middle-layer cloth by adopting a plain weaving method, and respectively drying and shaping the cloth; coating the back surface of the base cloth with an adhesive, and then forming a shaped shock absorption layer through a casting process or a calendering process; coating the front and back surfaces of the middle-layer cloth with an adhesive, then overlapping the middle-layer cloth with the base cloth with the shaping shock absorption layer, and performing high-temperature pressurization compounding to form a primary belt body; forming a surface wear-resistant layer on the surface of the primary belt body through a tape casting process or a calendering process, and performing embossing treatment to obtain a composite belt base body; the surface of the base cloth of the composite belt base body is coated with a self-lubricating material, a self-lubricating coating is formed through heating permeation and cooling solidification, and the self-lubricating composite belt is prepared. Through unique self-lubricating material combination and structural design, the ultra-low friction coefficient, lifelong refueling-free and self-cleaning functions of the product are achieved, the service life of the product is remarkably prolonged, and the energy-saving performance of the product is remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of transmission belt technology, specifically relating to a self-lubricating composite belt and its preparation method. Background Technology

[0002] In the fields of fitness equipment and industrial conveying, treadmill belts and conveyor belts with polyvinyl chloride (PVC) or polyurethane (PU) as the surface material are widely used. However, these traditional composite belts have problems such as a high coefficient of friction and easy dust accumulation between the bottom fabric and the running board or conveyor rollers of the equipment. After long-term use, users are prone to belt overheating, increased operating current leading to increased energy consumption, and severe wear and tear on the belt and running board / rollers, eventually leading to failure. More seriously, the resulting overheating and abnormal load may also damage the motors, controllers, and other electronic components of the equipment, and even cause a risk of burnout.

[0003] To mitigate the adverse effects of excessive friction and dust accumulation, a common practice in existing technologies is to require users to periodically add lubricants such as silicone oil to the treadmill or running board. This maintenance method is not only cumbersome but also has many drawbacks, including lubricant leakage polluting the environment, difficulty in controlling the amount added (too much can cause slippage and personal injury, while too little will result in insufficient lubrication), and users easily forgetting the maintenance cycle.

[0004] Currently, some "oil-free" treadmill belts have appeared on the market, aiming to extend maintenance cycles. The common practice is to coat the warp and weft yarns of the underlying fabric or the pre-formed composite belt base with various self-lubricating agents. However, this approach has inherent limitations: firstly, its self-lubricating effect is highly dependent on the integrity of the surface coating; under long-term friction, the coating is easily worn or peeled off, failing to achieve a durable "lifetime oil-free" effect; secondly, this method only focuses on adding lubricant later, without fundamentally reducing the coefficient of friction from the material and structural design of the underlying fabric, nor achieving significant self-cleaning functionality. Therefore, it remains a compromise solution with limited effectiveness and an unsatisfactory lifespan.

[0005] Similarly, conveyor belts, which are widely used in industrial conveyor lines, also face problems such as dust accumulation at the bottom, high energy consumption, and low energy efficiency due to long-term continuous operation and complex industrial environments. They also lack an ideal solution that can effectively achieve self-cleaning, energy saving and emission reduction, and structural simplification.

[0006] In view of this, the present invention proposes a self-lubricating composite belt and its preparation method, which can fundamentally achieve ultra-low friction, lifetime oil-free operation and efficient self-cleaning, significantly improving equipment energy efficiency and service life. Summary of the Invention

[0007] To address the problems of high friction coefficient, frequent manual lubrication, easy dust accumulation, high energy consumption, and short service life in the existing technologies, this invention provides a self-lubricating composite belt and its preparation method to solve the above-mentioned technical defects.

[0008] In a first aspect, the present invention provides a method for preparing a self-lubricating composite belt, the method comprising the following steps:

[0009] S1. The base fabric is woven using a herringbone weave as the bottom friction surface, and the middle layer fabric is woven using a plain weave as the reinforcing skeleton. The woven base fabric and middle layer fabric are then subjected to drying and shaping treatments.

[0010] S2. Apply adhesive to the reverse side of the base fabric, and then form a shaped shock-absorbing layer that is tightly bonded to the base fabric on the adhesive-coated surface through a casting process or a calendering process.

[0011] S3. Apply adhesive to both sides of the middle layer fabric, then overlap it with the bottom fabric with the shaped shock-absorbing layer obtained by S2, and perform high temperature and pressure bonding to form the primary belt.

[0012] S4. A surface wear-resistant layer is formed on the surface of the primary belt through a casting or calendering process, and the incompletely cured surface wear-resistant layer is embossed to obtain a composite belt substrate.

[0013] S5. The self-lubricating material is coated onto the surface of the base fabric of the composite tape, and then heated to penetrate and cooled to cure, forming a self-lubricating coating on the surface of the base fabric, thus obtaining the self-lubricating composite tape.

[0014] Preferably, in step S1, the herringbone weave of the base fabric is as follows: the warp yarns are made of a blend of polytetrafluoroethylene fiber and polyester fiber, and the weft yarns are made of polyester monofilament or nylon filament.

[0015] More preferably, the warp yarns are a 1:1 blend of 1000D polytetrafluoroethylene fiber and 450D polyester fiber, and the weft yarns are 0.2mm diameter polyester monofilaments, with a weaving density of 108 warp yarns and 30 weft yarns per inch.

[0016] Preferably, in step S1, the plain weave of the middle layer fabric is as follows: the warp yarns are made of a blend of polyester fiber filaments and aramid fiber filaments, and the weft yarns are made of polyester monofilaments.

[0017] More preferably, the warp yarns are a blend of 1000D polyester fiber filaments and 1000D aramid fiber filaments in a ratio of 14:1, the weft yarns are polyester monofilaments with a diameter of 0.2mm, and the weaving density is 56 warp yarns and 22 weft yarns per inch.

[0018] Preferably, in steps S2 and S4, the polymer material used in the casting process is polyurethane, and the polymer material used in the calendering process is polyvinyl chloride.

[0019] Preferably, in step S5, the self-lubricating material is composed of the following components by weight percentage: 50%-70% dimethyl silicone oil, 20%-40% polyethylene wax, 0.5%-2% silane coupling agent, and 5%-15% polytetrafluoroethylene powder.

[0020] More preferably, the self-lubricating material is composed of the following components by weight percentage: 60% dimethyl silicone oil with a viscosity of 500, 30% polyethylene wax with a melting point of 90 degrees Celsius, 1% KH-550 silane coupling agent, and 9% polytetrafluoroethylene powder with a molecular weight of 10K.

[0021] Preferably, in step S5, the heating penetration is carried out at a temperature of 180℃±5℃, the linear velocity of the composite tape matrix passing through the heating zone is 10 m / min±0.5 m / min, and the cooling and curing is carried out by cooling air at 20℃-25℃ for 3-5 minutes.

[0022] Secondly, the present invention proposes a self-lubricating composite belt, which is prepared by any of the above-mentioned methods for preparing self-lubricating composite belts.

[0023] In summary, compared with the prior art, the self-lubricating composite belt and its preparation method provided by the present invention have the following beneficial effects:

[0024] (1) Achieving ultra-low coefficient of friction and significant energy-saving effect: Due to the use of polytetrafluoroethylene (PTFE) fiber as the warp yarn material of the base fabric, this material itself has an ultra-low coefficient of friction of 0.01-0.05. Combined with the point contact structure formed by the herringbone weave, the frictional resistance is reduced from both the material and structural levels. This allows the coefficient of friction of the final product to be as low as 0.1-0.15 (far lower than the common 0.18-0.26 in the market), and the operating current of the equipment can be reduced by 10%-20%, achieving a significant energy-saving effect.

[0025] (2) Achieves a lifetime lubrication effect without the need for lubrication: By employing a specific self-lubricating material formula (including dimethyl silicone oil, polyethylene wax, polytetrafluoroethylene powder, etc.) combined with an optimized coating and heat treatment process (heating penetration at 180℃±5℃, cooling curing at 20℃-25℃), the self-lubricating material can fully penetrate and firmly adhere to the base fabric fibers, forming a durable and effective lubricating layer. This lubricating layer is not easily damaged by wear, thus achieving the product's lifetime lubrication-free function.

[0026] (3) Excellent dimensional stability and tensile strength were achieved: Due to the introduction of aramid and polyester fibers into the middle layer fabric, the tensile strength of aramid fibers, which is as high as 2.8-3.6 GPa, was significantly enhanced, thus significantly improving the tensile strength of the composite tape. This allows the elongation rate of the product to be stably controlled within 2% (far lower than the common 3%-4.5% in the market), effectively preventing elongation deformation during use, reducing the number of maintenance and adjustment times, and extending the service life.

[0027] (4) Excellent self-cleaning ability: The inherent low surface energy and non-stick properties of PTFE fibers in the base fabric, combined with the surface texture formed by the herringbone weave, work together to make it difficult for dust to adhere and easy to remove. Through dust adhesion tests, this invention can remove 95% of dust, far exceeding existing products on the market that can only remove about 50% of dust, keeping the contact surface clean and reducing increased friction and equipment damage caused by dust accumulation.

[0028] (5) It demonstrates good applicability and comprehensive performance: By selecting polyurethane (PU) or polyvinyl chloride (PVC) as polymer materials for the shaping shock absorption layer and the surface wear-resistant layer, the product performance can be flexibly adjusted according to the needs of different application scenarios (such as treadmills or industrial conveyor belts), while ensuring the core functions of ultra-low friction, self-lubrication and self-cleaning, and meeting diverse usage requirements. Attached Figure Description

[0029] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0030] Figure 1 A flowchart illustrating a method for preparing a self-lubricating composite belt according to the present invention;

[0031] Figure 2 This is a schematic diagram of the layered structure of the self-lubricating composite tape according to the present invention.

[0032] Figure description: 1. Self-lubricating coating layer; 2. Base fabric layer; 3. Shaping and shock-absorbing layer; 4. Middle fabric layer; and 5. Surface wear-resistant textured layer. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] This invention provides a method for preparing a self-lubricating composite belt, the method comprising the following steps:

[0036] S1. A base fabric is woven using a herringbone weave as the bottom friction surface, and a middle layer fabric is woven using a plain weave as the reinforcing skeleton. Both the base and middle layers are then subjected to drying and setting treatments. The herringbone weave of the base fabric consists of warp yarns made from a blend of polytetrafluoroethylene (PTFE) and polyester fibers, with PTFE fibers comprising 1% to 100% of the warp yarns by weight. The weft yarns are made of polyester monofilament or nylon yarn. Specifically, the warp yarns are a 1:1 blend of 1000D PTFE and 450D polyester fibers, and the weft yarns are 0.2mm diameter polyester monofilaments. The weaving density is 108 warp yarns and 30 weft yarns per inch. The plain weave of the middle layer fabric consists of warp yarns made from a blend of polyester and aramid fibers, and the weft yarns are made of polyester monofilament. Specifically, the warp yarns are a blend of 1000D polyester fiber and 1000D aramid fiber in a 14:1 ratio, and the weft yarns are polyester monofilaments with a diameter of 0.2mm. The weaving density is 56 warp yarns and 22 weft yarns per inch.

[0037] S2. Apply adhesive to the reverse side of the base fabric, and then form a shaped shock-absorbing layer that is tightly bonded to the base fabric on the adhesive-coated surface using a casting process. The polymer material used in the casting process is polyurethane, and the polymer material used in the calendering process is polyvinyl chloride.

[0038] S3. Apply adhesive to both sides of the middle layer fabric, then overlap it with the bottom fabric with the shaped shock-absorbing layer obtained by S2, and perform high temperature and pressure bonding to form the primary belt.

[0039] S4. A surface wear-resistant layer can be formed on the surface of the primary belt through either a casting process or a calendering process. The incompletely cured surface wear-resistant layer is then embossed to obtain the composite belt substrate. The polymer material used in the casting process is polyurethane, and the polymer material used in the calendering process is polyvinyl chloride.

[0040] S5. The self-lubricating material is coated onto the surface of the base fabric of the composite tape substrate, and then heated for penetration and cooled for curing (heating penetration is carried out at a temperature of 180℃±5℃, the linear velocity of the composite tape substrate through the heating zone is 10 m / min±0.5 m / min, and cooling for curing is carried out by cooling air at 20℃-25℃ for 3-5 minutes), forming a firm self-lubricating coating on the surface of the base fabric, and finally obtaining the self-lubricating composite tape.

[0041] The self-lubricating material is composed of the following components by weight percentage: 50%-70% dimethyl silicone oil, 20%-40% polyethylene wax, 0.5%-2% silane coupling agent, and 5%-15% polytetrafluoroethylene powder. A preferred self-lubricating material is composed of the following components by weight percentage: 60% dimethyl silicone oil with a viscosity of 500, 30% polyethylene wax with a melting point of 90 degrees Celsius, 1% KH-550 silane coupling agent, and 9% polytetrafluoroethylene powder with a molecular weight of 10K.

[0042] It should be noted that the formulation of the above self-lubricating material can be equivalently replaced or adjusted according to actual needs without deviating from the core principle of the present invention.

[0043] For example, the wax is not limited to polyethylene wax; materials with similar lubricating properties, such as microcrystalline wax, can also be used. The activator can be a silane coupling agent (such as KH-550) to improve coating adhesion, or other types of coupling agents can be selected according to the characteristics of the substrate. Polytetrafluoroethylene powder is preferred as the polymeric lubricant, but other polymeric powders with self-lubricating properties can also be used. Roller coating is used as an example of the self-lubricating coating process, but those skilled in the art will understand that other processes that can achieve uniform coating, such as spraying and dipping, are also applicable to this invention.

[0044] The present invention also proposes a self-lubricating composite belt, which is prepared by the above-mentioned method for preparing self-lubricating composite belt. Figure 2 A schematic diagram of the layered structure of the self-lubricating composite tape of the present invention is shown. For example... Figure 2 As shown, the self-lubricating composite belt includes: a self-lubricating coating layer 1, a base fabric layer 2, a shaping and shock-absorbing layer 3, a middle fabric layer 4, and a surface wear-resistant textured layer 5.

[0045] The self-lubricating composite belt and its preparation method provided by the present invention will be described in detail below with reference to Examples 1-4. It should be understood that experimental methods in the embodiments of the present invention, unless otherwise specified, are generally performed under conventional conditions in the art or as recommended by the manufacturer.

[0046] Example 1: TPU / TPU five-layer self-lubricating running belt

[0047] This embodiment prepares a five-layer self-lubricating running belt for high-end treadmills, which, from top to bottom, consists of: a TPU surface abrasion-resistant layer, a middle fabric layer, a TPU shaping and shock-absorbing layer, a low-friction base fabric layer, and a self-lubricating coating layer. The preparation method includes the following steps:

[0048] S1. Weaving and Pre-treatment:

[0049] The base fabric is woven using a herringbone weave. The warp yarns are a 1:1 blend of 1000D (Denier) polytetrafluoroethylene (PTFE) fibers and 450D polyester (PET) fibers; the weft yarns are 0.2mm diameter polyester monofilaments. The weaving density is set at 108 warp threads / inch and 30 weft threads / inch, woven in an orderly fashion.

[0050] The middle layer fabric is woven using a plain weave. The warp yarns are a blend of 1000D polyester (PET) and 1000D para-aramid (Kevlar) fibers in a 14:1 ratio; the weft yarns are 0.2mm diameter polyester monofilaments. The weaving density is set at 56 threads / inch in the warp and 22 threads / inch in the weft, and an orderly weaving process is employed.

[0051] The woven base fabric and middle layer fabric are placed on the production line for baking at a temperature of 170℃±5℃ to eliminate internal stress and fix the fabric size and shrinkage rate.

[0052] S2, Forming a base fabric composite:

[0053] A layer of thermoplastic polyurethane (TPU) adhesive is uniformly coated onto the reverse side of the S1-treated backing fabric (the side not in contact with the running board). Subsequently, a TPU-shaped shock-absorbing layer with a thickness of approximately 0.4 mm is cast onto the coated surface using a TPU casting process, with the casting temperature controlled at 175℃±5℃. This results in a backing fabric composite consisting of a low-friction backing fabric layer and a TPU-shaped shock-absorbing layer.

[0054] S3. Prepare and composite the middle layer fabric composite:

[0055] TPU adhesive is evenly coated on both sides of the middle layer fabric after S1 treatment. Then, the coated side is precisely overlaid with the TPU shaping and shock-absorbing layer of the base fabric composite obtained in S2. The composite is sent into the casting production line and subjected to high-temperature and high-pressure bonding at a temperature of 175℃±5℃ and a pressure of 0.8MPa to firmly bond the layers and form a primary tape containing a low-friction base fabric layer, a TPU shaping and shock-absorbing layer, and a middle layer fabric.

[0056] S4. Form the surface layer and emboss:

[0057] On the surface of the middle layer of the primary tape obtained in S3 (i.e., the side opposite to the S3 composite surface), a TPU surface abrasion-resistant layer with a thickness of approximately 0.4 mm is formed through a casting process production line. Before the TPU layer is fully cured, it is immediately embossed using an embossing roller to form a surface texture with anti-slip function, thus obtaining the final composite tape substrate.

[0058] S5, Self-lubricating coating:

[0059] The self-lubricating coating material was formulated with the following composition by weight percentage: 60% dimethyl silicone oil (500 cSt viscosity), 30% polyethylene wax (90℃ melting point), 1% KH-550 silane coupling agent, and 9% polytetrafluoroethylene powder (10K molecular weight). Using a melt blending method, the above-mentioned materials were stirred and heated to a molten state in a heated container to ensure thorough and uniform mixing. The molten self-lubricating material was then applied very evenly and precisely to the base fabric surface (i.e., the surface of the low-friction base fabric layer) of the composite belt substrate using a roller coating or dipping production equipment. Subsequently, the coated belt was passed through a 180℃ oven at a linear speed of 10 m / min to allow the self-lubricating material to fully melt and penetrate into the warp and weft yarns of the base fabric. Finally, the belt was cooled with 23℃ cooling air for 4 minutes to cure and set the self-lubricating coating, thus obtaining the self-lubricating running belt.

[0060] The 1.8mm thick self-lubricating TPU running belt product prepared in this embodiment was tested, and its dynamic friction coefficient with the running board was 0.12. After a 4000-hour durability test with a load of 160KG, the belt elongation was less than 1.8%. Under the same load conditions, the driving motor operating current was reduced by an average of about 15% compared with traditional PU running belts, and the noise reduction effect during operation was significant, requiring no manual lubrication maintenance.

[0061] Example 2: PVC / PVC five-layer self-lubricating conveyor belt

[0062] This embodiment prepares a five-layer self-lubricating conveyor belt for industrial light-duty conveyor lines, which, from top to bottom, consists of: a PVC surface wear-resistant textured layer, a middle fabric layer, a PVC shaped shock-absorbing layer, a low-friction base fabric layer, and a self-lubricating coating layer. The preparation method includes the following steps:

[0063] S1. Weaving and Pre-treatment:

[0064] This step is exactly the same as step S1 in Example 1. That is, after weaving and drying the fabric at 170°C in an assembly line, the desired base fabric and middle layer fabric are obtained.

[0065] S2, Forming a base fabric composite:

[0066] A polyvinyl chloride (PVC) paste resin adhesive is uniformly coated onto the reverse side of the base fabric after S1 treatment. Subsequently, a PVC shaped shock-absorbing layer with a thickness of approximately 0.7 mm is formed on the coated surface using PVC calendering equipment, with the calendering temperature controlled at 185℃. This results in a base fabric composite consisting of a low-friction base fabric layer and a PVC shaped shock-absorbing layer.

[0067] S3. Prepare and composite the middle layer fabric composite:

[0068] PVC paste resin adhesive is evenly coated on both sides of the middle layer fabric after S1 treatment. Then, the coated side is precisely overlaid with the PVC shaping and shock-absorbing layer of the base fabric composite obtained in S2. The composite is sent into a calendering or coating production line and subjected to high-temperature and high-pressure bonding at 185°C and 0.7MPa to firmly bond the layers, forming a primary belt containing a low-friction base fabric layer, a PVC shaping and shock-absorbing layer, and a middle layer fabric.

[0069] S4. Form the surface layer and emboss:

[0070] On the surface of the middle layer of the primary belt obtained in S3, a PVC surface wear-resistant layer with a thickness of approximately 0.5 mm is formed by PVC calendering or coating. Before the PVC layer is fully cured, it is immediately embossed with an embossing roller to form an anti-slip texture, thus obtaining the composite belt substrate.

[0071] S5, Self-lubricating coating:

[0072] A self-lubricating coating material was prepared with the same composition as in Example 1, comprising, by weight percentage: 60% dimethyl silicone oil with a viscosity of 500 cSt, 30% polyethylene wax with a melting point of 90°C, 1% KH-550 silane coupling agent, and 9% polytetrafluoroethylene powder with a molecular weight of 10K. The above-mentioned formulation materials were stirred and heated to a molten state in a heated container using a melt blending method to ensure thorough and uniform mixing. The molten self-lubricating material was then applied very evenly and precisely to the base fabric surface (i.e., the surface of the low-friction base fabric layer) of the composite belt substrate using a roller coating or dipping production equipment. Subsequently, the coated belt was passed through a 180°C oven at a linear speed of 10 m / min to allow the self-lubricating material to fully melt and penetrate into the warp and weft yarns of the base fabric. Finally, the belt was cooled with 23°C cooling air for 4 minutes to cure and set the self-lubricating coating. A self-lubricating running belt or conveyor belt with a double-layer PVC / PVC five-layer structure and a thickness of 2.5 mm was ultimately obtained.

[0073] The product of this embodiment was tested and found to have a coefficient of friction of 0.14. After 2400 hours of continuous operation under a load of 150kg, the belt showed no significant elongation, and the drive energy consumption was reduced by approximately 12% compared to traditional conveyor belts of the same type, demonstrating excellent durability and energy-saving performance.

[0074] Example 3: PVC / PU five-layer self-lubricating composite tape

[0075] This embodiment prepares a five-layer composite tape that combines economy and a good tactile feel. From top to bottom, it consists of: a PU surface abrasion-resistant textured layer, a middle fabric layer, a PVC shaping and shock-absorbing layer, a low-friction base fabric layer, and a self-lubricating coating layer. The preparation method includes the following steps:

[0076] S1. Weaving and Pre-treatment: This step is exactly the same as S1 in Example 1.

[0077] S2. Forming the base fabric composite: This step is exactly the same as step S2 in Example 2, forming a PVC shaped shock-absorbing layer.

[0078] S3. Preparation and lamination of the middle layer fabric composite: This step is exactly the same as S3 in Example 2.

[0079] S4. Forming and texturing the surface layer: Same as step S4 in Example 1, casting to form a wear-resistant PU surface layer and texturing.

[0080] S5, Self-lubricating coating: This step is exactly the same as S5 in Example 1. A five-layer PVC / PU self-lubricating composite tape is finally obtained.

[0081] The product in this embodiment has a coefficient of friction of 0.13. Its surface has a comfortable feel, provides better noise reduction than pure PVC structures, and exhibits good tear resistance, making it particularly suitable for indoor fitness equipment or food-grade conveying environments where noise levels are a concern.

[0082] Example 4: PVC / PVC four-layer self-lubricating composite tape

[0083] As a simplified variant of the method described above in this invention, this embodiment provides a four-layer self-lubricating composite tape that omits the middle layer fabric. It is also based on the core concept of this invention and is particularly suitable for light-load, low-cost applications. Its structure, from top to bottom, consists of: a PVC surface abrasion-resistant textured layer, a PVC shaped shock-absorbing layer, a low-friction base fabric layer, and a self-lubricating coating layer. This structure omits the middle layer fabric. The preparation method includes the following steps:

[0084] S1. Weaving and Pre-treatment:

[0085] Only the base fabric is woven, and its weaving process and parameters (herringbone weave, PTFE / PET blended warp yarns, etc.) are exactly the same as those for the base fabric in Example 1. It is then dried and set at 175°C on an assembly line. The weaving and pretreatment of the middle layer fabric are omitted in this example.

[0086] S2, Formation of a composite matrix:

[0087] This step involves producing PVC hot melt through a separate calendering process, followed by a coating process, to sequentially build two PVC layers with different functions on the base fabric.

[0088] First, on the reverse side of the base fabric after S1 treatment, a PVC shaping and shock-absorbing layer with a thickness of approximately 0.4mm is formed through a first PVC calendering process. This layer mainly serves to bond with the base fabric, provide basic rigidity to the belt, and provide cushioning.

[0089] Subsequently, a second PVC coating process is applied to the surface of the PVC shaped shock-absorbing layer to form a PVC surface wear-resistant layer with a thickness of approximately 0.4 mm. Before this PVC layer is fully cured, it is immediately embossed with an embossing roller to form anti-slip textures.

[0090] Through these two production processes, a composite matrix consisting of a PVC shaped shock-absorbing layer and a PVC surface wear-resistant textured layer is finally produced on the base fabric.

[0091] S3, Self-lubricating coating:

[0092] The self-lubricating coating material was prepared, and its composition by weight percentage was: 65% dimethyl silicone oil with a viscosity of 1000 cSt, 30% polyethylene wax with a melting point of 95℃, 0.8% KH-550 silane coupling agent, and 5% polytetrafluoroethylene powder with a molecular weight of 5K. After being coated onto the surface of the base fabric of the composite tape using a roller coating device, the tape was heated and permeated in an oven at 175℃ at a linear speed of 15 m / min, and finally cooled and shaped. The final product was a four-layer structure PVC self-lubricating composite tape with a single layer of fabric and two layers of adhesive.

[0093] The product in this embodiment has a simple structure and significantly reduced cost. Its coefficient of friction is 0.18, and tests show that it has good self-cleaning function, effectively reducing dust adsorption by more than 80%, fully meeting the maintenance-free requirements of light-load applications.

[0094] Comparative example: Traditional conveyor belt / treadmill belt

[0095] This comparative example demonstrates a traditional three-layer composite belt, consisting of, from top to bottom: a PVC or PU abrasion-resistant surface layer, and a plain polyester fabric layer (serving as both the skeleton and in contact with the transmission mechanism). The preparation method includes the following steps:

[0096] S1. Weaving and Pre-treatment:

[0097] A base fabric is woven using a conventional plain weave method, with both warp and weft yarns made of ordinary polyester fibers, without the use of any special functional fibers such as PTFE or aramid fibers. The woven base fabric is then subjected to a drying and setting process.

[0098] S2, Formation of composite bands:

[0099] A PVC or PU adhesive is applied to the reverse side of the base fabric after S1 treatment (i.e. the side to be in contact with the running board / roller). Then, a PVC or PU surface abrasion layer (which is usually thick and combines volume filling and surface abrasion resistance) is formed directly on the front side of the base fabric through a coating process. The fabric is then embossed to obtain the traditional composite belt substrate.

[0100] This comparative example completely omits the weaving and lamination steps of the independent shaping and shock-absorbing layer and the middle layer fabric, and also completely omits the self-lubricating coating step (i.e., steps S3, S4 and S5 in this invention are not included).

[0101] The final product is a traditional three-layer PVC or PU conveyor belt / running belt. Before and during use, users need to manually add lubricating oil such as dimethyl silicone oil to the transmission mechanism periodically for lubrication and maintenance.

[0102] This traditional product has a high initial coefficient of friction (typically greater than 0.20), and after a period of use, due to the lack of self-lubricating properties and durable lubricating coating in ordinary polyester backing fabric, the coefficient of friction will significantly increase to over 0.25-0.30. Simultaneously, due to the lack of an independent high-strength reinforcing layer (such as an aramid-blend mid-layer fabric) and effective dimensional stability design, the belt elongation under long-term tension is as high as 3.5%-4.5%, requiring frequent tension adjustments. Furthermore, ordinary polyester backing fabric easily attracts dust, which mixes with lubricating oil to form sludge, exacerbating wear and slippage risks, completely failing to achieve self-cleaning and lifetime maintenance-free functionality.

[0103] Table 1 summarizes the performance comparison of implementation examples 1-5 and comparative examples:

[0104] Table 1 Performance Comparison Summary Table

[0105]

[0106] As shown in Table 1, Examples 1-5 and the comparative examples fully demonstrate that the present invention, through specific bottom fabric materials, structural design and self-lubricating coating process, successfully prepares a variety of high-performance self-lubricating composite tapes, which can effectively solve the problems of high friction coefficient, easy stretching and deformation, need for regular maintenance and serious dust adsorption of traditional products.

[0107] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention is not limited to the specific combination of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this invention.

Claims

1. A method for preparing a self-lubricating composite belt, characterized in that, Includes the following steps: S1. A base fabric is woven using a herringbone weave as the bottom friction surface, and a middle layer fabric is woven using a plain weave as the reinforcing skeleton. The woven base fabric and the middle layer fabric are then subjected to drying and shaping treatments. S2. Apply adhesive to the reverse side of the base fabric, and then form a shaped shock-absorbing layer that is tightly bonded to the base fabric on the adhesive-coated surface by a casting process or a calendering process. S3. Apply adhesive to both sides of the middle layer fabric, then overlap it with the bottom fabric with the shaping and shock-absorbing layer obtained by S2, and perform high-temperature and high-pressure bonding to form a primary belt. S4. A surface wear-resistant layer is formed on the surface of the primary belt body by a casting process or a calendering process, and the incompletely cured surface wear-resistant layer is embossed to obtain a composite belt matrix. S5. The self-lubricating material is coated onto the surface of the base fabric of the composite tape substrate, and then heated to penetrate and cooled to cure, forming a self-lubricating coating on the surface of the base fabric, thus finally obtaining the self-lubricating composite tape.

2. The method for preparing the self-lubricating composite belt according to claim 1, characterized in that, In step S1, the herringbone weave of the base fabric is as follows: the warp yarns are made of a blend of polytetrafluoroethylene fiber and polyester fiber, and the weft yarns are made of polyester monofilament or nylon yarn.

3. The method for preparing the self-lubricating composite belt according to claim 2, characterized in that, The warp yarns are a 1:1 blend of 1000D polytetrafluoroethylene fiber and 450D polyester fiber, and the weft yarns are 0.2mm diameter polyester monofilaments. The weaving density is 108 warp yarns and 30 weft yarns per inch.

4. The method for preparing the self-lubricating composite belt according to claim 1, characterized in that, In step S1, the plain weave of the middle layer fabric is as follows: the warp yarns are made of a blend of polyester fiber filaments and aramid fiber filaments, and the weft yarns are made of polyester monofilaments.

5. The method for preparing the self-lubricating composite belt according to claim 4, characterized in that, The warp yarns are a blend of 1000D polyester fiber filaments and 1000D aramid fiber filaments in a ratio of 14:1, and the weft yarns are polyester monofilaments with a diameter of 0.2mm. The weaving density is 56 warp yarns and 22 weft yarns per inch.

6. The method for preparing the self-lubricating composite belt according to claim 1, characterized in that, In steps S2 and S4, the polymer material used in the casting process is polyurethane, and the polymer material used in the calendering process is polyvinyl chloride.

7. The method for preparing the self-lubricating composite belt according to claim 1, characterized in that, In step S5, the self-lubricating material is composed of the following components by weight percentage: 50%-70% dimethyl silicone oil, 20%-40% polyethylene wax, 0.5%-2% silane coupling agent, and 5%-15% polytetrafluoroethylene powder.

8. The method for preparing the self-lubricating composite belt according to claim 7, characterized in that, The self-lubricating material is composed of the following components by weight percentage: 60% dimethyl silicone oil with a viscosity of 500, 30% polyethylene wax with a melting point of 90 degrees Celsius, 1% KH-550 silane coupling agent, and 9% polytetrafluoroethylene powder with a molecular weight of 10K.

9. The method for preparing the self-lubricating composite belt according to claim 1, characterized in that, In step S5, the heating penetration is carried out at a temperature of 180℃±5℃, the linear velocity of the composite tape matrix passing through the heating zone is 10 m / min±0.5 m / min, and the cooling and curing is carried out by cooling air at 20℃-25℃ for 3-5 minutes.

10. A self-lubricating composite belt, characterized in that, The self-lubricating composite tape is prepared by the method for preparing the self-lubricating composite tape according to any one of claims 1 to 9.

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