High-flexibility and high-filling-coefficient steel wire rope

Abstract

The invention relates to the technical field of steel wire ropes, and particularly discloses a high-flexibility and high-filling-coefficient steel wire rope which structurally comprises a center layer, middle layers, a secondary outer layer and an outer layer which are sequentially arranged from inside to outside, the center layer is a first filling rope core, the middle layers are six middle layer rope cores arranged in a surrounding mode, and the secondary outer layer is a second filling rope core. The secondary outer layer comprises twelve second filling rope cores and six groups of secondary outer layer stranded ropes, the outer layer comprises sixty outer layer stranded ropes, the first filling rope cores and the second filling rope cores are the same in structure and each comprise a center stranded rope and twenty-one fiber cores surrounding the outer wall of the center stranded rope, and the surfaces of the fiber cores are coated with elastic filling coatings; the filling coefficient is increased through the multi-layer surrounding structural design, gaps in the rope body are reduced, the overall flexibility is enhanced and extrusion friction between layers is buffered through the synergistic effect of the elastic center strand rope, the carbon fiber core and the elastic filling coating, and the structural stability and durability of the steel wire rope are guaranteed while high flexibility and high filling coefficient are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steel wire rope, and particularly relates to a high-flexibility and high-filling-factor steel wire rope. BACKGROUND

[0002] As a flexible combination unit with steel wires as basic units and twisted together, the steel wire rope is widely applied to the fields of engineering machinery, mine exploitation, elevator transportation and the like due to its excellent tensile strength, load stability and wear resistance. With the upgrading of modern industry towards large-scale, high-efficiency and light-weight, the traditional steel wire rope gradually cannot meet the performance adaptability, and the specific manifestations are the problems of "insufficient flexibility" and "low filling degree".

[0003] In order to improve the flexibility and filling degree of the steel wire rope, the existing technology mainly improves from the aspects of material and structure optimization. In the aspect of structure, the arrangement mode of the core and the strand is optimized, such as adopting a multi-strand layered twisting structure to reduce the gap space inside the rope body, and adjusting the twisting angle to reduce the friction resistance between the strands, so as to improve the overall flexibility. In the aspect of material selection, the traditional metal core is replaced by a fiber core in some schemes, the bending performance of the steel wire rope is improved by using the light weight and elasticity of the fiber material, and a simple coating is coated on the surface of the core in another technology to fill the small gap and enhance the protection effect.

[0004] However, the above improvement measures still have obvious deficiencies. Specifically, the tensile performance and elasticity of the existing fiber core material are insufficient, and the permanent deformation easily occurs under the load when used alone, which leads to the attenuation of the flexibility of the steel wire rope with the use time, and the traditional coating is mainly made of rigid material and has limited deformation capacity, which cannot fully fill the gap dynamically generated inside the rope body, and the filling effect is unstable. SUMMARY

[0005] In view of the technical defects in the background art, the present application provides a high-flexibility and high-filling-factor steel wire rope. In order to further solve the above technical problems and meet the actual needs, the specific technical scheme is as follows: The utility model provides a kind of high flexibility and high filling coefficient steel wire rope, including the center layer, middle layer, secondary outer layer and outer layer that are sequentially arranged from inside to outside, the center layer is a first filling rope core, the middle layer is six middle layer rope cores that are arranged around the outside of first filling rope core, the secondary outer layer includes twelve second filling rope cores and six groups of secondary outer layer strands, twelve second filling rope cores are arranged around the outside of six middle layer rope cores, and six groups of secondary outer layer strands are annularly and equidistantly distributed between second filling rope core and outer layer, each group of secondary outer layer strands is composed of six strands arranged in arc, and the outer layer is sixty outer layer strands arranged around the outside of twelve second filling rope cores, the first filling rope core and second filling rope core are the same in structure, and each includes a center strand and twenty-one fiber cores arranged around the outer wall of the center strand, and the surface of the fiber core is coated with an elastic filling coating.

[0006] As a further technical solution of the utility model, the thickness of the elastic filling coating is 1 / 4-1 / 5 of the diameter of the fiber core, the fiber core is made of carbon fiber, and the secondary outer layer strands, outer layer strands and middle layer rope cores are steel wire ropes made of galvanized steel wires.

[0007] As a further technical solution of the utility model, the preparation process of the center strand is as follows: PET, modified maleic anhydride grafted polypropylene and modified EPDM are mixed, and then they are melt-blended at 240-260℃ for 10 min; zinc stearate and antioxidant 168 are added and stirred for 5 min to obtain a spinning material; the spinning material is fed into a spinning machine, and the spinning material is spun at 260-280℃, and then the center strand is prepared after bunching, drawing at a speed of 500-800 m / min and crimping.

[0008] As a further technical solution of the utility model, the preparation method of the modified maleic anhydride grafted polypropylene is as follows: 50-70 parts of maleic anhydride grafted polypropylene and 90-110 parts of xylene solvent are mixed, and then they are heated to 100-110℃ under nitrogen protection until they are completely dissolved; subsequently, a mixed solution containing 5-10 parts of glycidyl methacrylate (GMA) and 0.5-1.0 parts of dicumyl peroxide (DCP) initiator is slowly added dropwise; after the dropwise addition is completed, the reaction is carried out at 100-110℃ for 2-3 hours; after the reaction is completed, the product is poured into cold ethanol for precipitation, and then it is filtered and washed with ethanol for 3 times; and finally, it is dried at 60℃ under vacuum until the weight is constant to obtain the epoxy-modified maleic anhydride grafted polypropylene.

[0009] As a further technical solution of the present invention, the preparation method of the modified EPDM rubber is as follows: First, 35-45 parts of polyethylene glycol 400 and 8-12 parts of maleic anhydride are mixed and stirred at 80-90°C for 2 hours to form PEG-maleic ester. Then, 25-35 parts of EPDM rubber, 1.5-2.5 parts of benzophenone and 1-2 parts of mercaptopropionic acid are added. Under a nitrogen atmosphere, the reaction system is irradiated with ultraviolet light with a wavelength of 365nm and a power of 500W for 1-2 hours. After the reaction is completed, the product is dissolved in toluene, then precipitated in ethanol, filtered and dried to obtain PEG grafted modified EPDM rubber.

[0010] As a further technical solution of the present invention, the elastic filler coating comprises, by weight, the following components: 40-60 parts acrylate emulsion, 1-2 parts defoamer, 1-4 parts propylene glycol, and 0.3-0.4 parts thickener; the acrylate emulsion comprises, by total weight, 40-50 parts methyl methacrylate, 35-40 parts butyl acrylate, 2-3 parts acrylic acid, 4-5 parts glycidyl methacrylate, 2-4 parts modified carbon nanofibers, 1-2 parts emulsifier, 0.6-0.8 parts pH buffer, 1.3-1.4 parts initiator, and 80-95 parts purified water; the defoamer is alkyl polyoxyethylene ether, the thickener is hydroxypropyl methylcellulose, the emulsifier is alkylphenol polyoxyethylene ether, the pH buffer is sodium bicarbonate, and the initiator is ammonium persulfate.

[0011] As a further technical solution of the present invention, the preparation process of the elastic filling coating includes: (a) Preparation of modified carbon nanofibers: Take 5-8 parts of carbon nanofibers and place them in a mixture of concentrated sulfuric acid / concentrated nitric acid with a volume ratio of 3:1. Stir the mixture in an oil bath at 70-80℃ for 3 hours. After filtration and washing until neutral, dry the mixture under vacuum at 60℃. (b) Preparation of acrylate emulsion: Methyl methacrylate, butyl acrylate, acrylic acid, glycidyl methacrylate, modified carbon nanofibers, emulsifier and purified water are mixed and stirred at high speed for 30 min. The temperature is raised to 85-90℃ and initiator and pH buffer are added. The reaction is kept at the temperature for 5-6 h and then cooled and discharged. (c) Coating preparation: Mix the acrylic emulsion, defoamer and propylene glycol for 10 min and let stand for 15 min to defoam. Add thickener and stir at low speed for 5 min. (d) Coating: Immerse the fiber core in the coating for 5-10 seconds, dry at 60°C for 10 minutes, repeat 3-5 times until the preset thickness is achieved, and finally cure at 120°C for 30 minutes.

[0012] As a further technical solution of the present invention, the assembly process of the high-flexibility and high-filling-coefficient steel wire rope is as follows: (A) Rope core preparation: Prepare the first filling rope core and the second filling rope core, and spirally wind six middle layer rope cores around the outside of the first filling rope core with a tension of 5-10N. (B) Multi-layer twisting: Twelve second filler rope cores are twisted counterclockwise on the outside of the middle layer rope core. Six sets of secondary outer layer strands are first installed on the outside of the second filler rope core, and then sixty outer layer strands are twisted clockwise. The twisting angle is controlled at 12-15°. (C) Post-treatment: Heat set at 150℃ for 20 minutes, then apply anti-corrosion grease.

[0013] The beneficial effects of this invention are as follows: The central strands of the first and second filling rope cores are made of PET and modified polymer blend, which have both excellent tensile strength and elastic deformation capability. Combined with the toughness of the carbon fiber core, it effectively reduces the bending resistance of the steel wire rope and improves the overall softness. The elastic filling coating on the surface of the fiber core can adaptively adjust with the deformation of the steel wire rope, further enhancing the flexibility. The elastic coating can fill the gap between the fiber core and the steel wire. The design of the ring arrangement of twelve second filling rope cores and six sets of secondary outer layer strands, combined with the tight twisting of the sixty outer layer strands, greatly reduces the internal voids of the rope, increases the filling coefficient, and enhances the structural stability, avoiding local stress concentration caused by voids during use. Attached Figure Description

[0014] Fig. 1 This is a cross-sectional view of the wire rope of the present invention.

[0015] Fig. 2 This is a schematic diagram of the first and second filling rope cores of the present invention.

[0016] Reference numerals: 1-First filling core; 2-Middle core; 3-Second filling core; 4-Second outer strand; 5-Outer strand; 6-Center strand; 61-Fiber core; 62-Elastic filling coating. Detailed Implementation

[0017] The embodiments of the present invention will be described below with reference to the accompanying drawings and related examples. The embodiments of the present invention are not limited to the following examples, and the present invention relates to the relevant necessary components in this technical field, which should be regarded as well-known technology in this technical field and can be known and mastered by those skilled in this technical field.

[0018] like Figs. 1-2As shown, the present invention provides a technical solution: a high-flexibility and high-filling-coefficient steel wire rope, comprising a central layer, a middle layer, a secondary outer layer, and an outer layer arranged sequentially from the inside out. The central layer is a first filling rope core 1. The middle layer consists of six middle layer rope cores 2 arranged around the outside of the first filling rope core 1. The secondary outer layer includes twelve second filling rope cores 3 and six sets of secondary outer layer strands 4. The twelve second filling rope cores 3 are arranged around the outside of the six middle layer rope cores. The six sets of secondary outer layer strands 4 are distributed in a ring at equal intervals between the second filling rope cores 3 and the outer layer. Each set of secondary outer layer strands 4 consists of six strands arranged in an arc. The outer layer consists of sixty outer layer strands 5 arranged around the outside of the twelve second filling rope cores 3. The first filling rope core 1 and the second filling rope core 3 have the same structure, both including a central strand 6 and twenty-one fiber cores 61 wrapped around the outer wall of the central strand 6. The surface of the fiber cores 61 is covered with an elastic filling coating 62.

[0019] In the wire rope structure of the present invention, the hierarchical ring structure of the central layer first filling rope core 1, the middle layer rope core 2, the second outer layer second filling rope core 3, the second outer layer strand 4, and the outer layer strand 5 provides a structural basis for high filling density; twelve second filling rope cores 3 fill the gaps on the outside of the middle layer rope core 2, six sets of second outer layer strands 4 are distributed between the second filling rope core 3 and the outer layer, and sixty outer layer strands 5 tightly wrap the outside, greatly reducing the internal voids of the rope and improving the overall structural density.

[0020] In the wire rope structure of the present invention, the central strands 6 of the first filling core 1 and the second filling core 3 are made of materials such as PET through a specific process, and have excellent tensile strength and elasticity; twenty-one carbon fiber cores 61 surround the central strands 6, and the thickness of the surface elastic filling coating 62 is controlled at 1 / 4-1 / 5 of the diameter of the fiber cores 61. This not only fills the tiny gaps between the fiber cores 61, but its good deformation ability can also buffer the compression friction between the layers. Combined with the elastic properties of the central strands 6, this enhances the overall flexibility of the wire rope.

[0021] In the wire rope structure of this invention, the middle layer core 2, the second outer layer strand 4, and the outer layer strand 5 are made of galvanized steel wire, which complements the strength of the carbon fiber core 61; the acrylic emulsion substrate of the elastic filling coating 62 contains modified carbon nanofibers, which enhances the bonding force between the coating and the fiber core 61 and prevents the coating from falling off during use; the tension control and 12-15° twisting angle design during each layer twisting, combined with 150° heat setting and anti-corrosion grease coating, make the rope structure more stable, and while improving flexibility and filling coefficient, ensure the durability of the wire rope.

[0022] As one of the preferred embodiments of the present invention, the thickness of the elastic filling coating 62 is 1 / 4 to 1 / 5 of the diameter of the fiber core 61, the fiber core 61 is made of carbon fiber, and the secondary outer strand 4, the outer strand 5 and the middle core are steel wire ropes made of galvanized steel wire.

[0023] The fiber core 61 is made of carbon fiber, which has high strength and good mechanical stability. Combined with the elastic properties of the central strand 6, it can reduce the cumulative deformation of the core under stress and prevent the internal structure of the rope from loosening. The thickness of the elastic filling coating 62 is 1 / 4 to 1 / 5 of the diameter of the fiber core 61. This ensures that the coating completely covers the surface of the fiber core 61 and fully fills the tiny gap between the fiber core 61 and the central strand 6. It also avoids the coating being too thick, which would result in an excessively large core volume and affect the compatibility with the middle core 2, the second outer strand 4, and other structures. At the same time, it ensures that the coating has sufficient deformation space to buffer external impacts. The second outer strand 4, the outer strand 5, and the middle core are made of galvanized steel wire, which improves the corrosion resistance of the steel wire surface. The high tensile strength of the galvanized steel wire itself can meet the mechanical requirements of the wire rope under load. It forms a rigid-flexible complement with the carbon fiber core 61, so that the rope has high flexibility while maintaining structural strength.

[0024] As one of the preferred embodiments of the present invention, the preparation process of the central strand 6 is as follows: PET, modified maleic anhydride grafted polypropylene, and modified EPDM rubber are mixed and melt-blended at 240-260℃ for 10 min; zinc stearate and antioxidant 168 are added and stirred for another 5 min to obtain a spun fabric; the spun fabric is fed into a spinning machine and spun at 260-280℃, and after bundling, traction at a speed of 500-800 m / min, and crimping, the central strand 6 is obtained.

[0025] PET provides basic mechanical strength, modified maleic anhydride-grafted polypropylene enhances component compatibility, and modified EPDM rubber imparts elasticity. After mixing, these three components are melt-blended at 240-260℃ for 10 minutes to ensure complete melting without thermal degradation, providing sufficient time for uniform dispersion and a stable blend system. The addition of zinc stearate reduces friction between the melt and equipment, improving spinning smoothness. Antioxidant 168 inhibits oxidative aging at high temperatures. Continued stirring for 5 minutes ensures uniform dispersion of the additives, avoiding localized performance differences. Spinning is carried out at 220-240℃ to further reduce melt viscosity, facilitating smooth filament formation. A traction speed of 500-800 m / min improves strength by stretching the molecular chains and avoids excessively thin fibers that are prone to breakage. The bundling process gathers the monofilaments into strands, enabling them to subsequently fit and wrap around the twenty-one fiber cores 61, forming the central strands 6 of the first and second filling cores 1 and 3.

[0026] As one of the preferred embodiments of the present invention, the preparation method of the modified maleic anhydride grafted polypropylene is as follows: 50-70 parts of maleic anhydride grafted polypropylene are mixed with 90-110 parts of xylene solvent, and heated to 100-110°C under nitrogen protection to completely dissolve it. Then, a mixed solution containing 5-10 parts of glycidyl methacrylate (GMA) and 0.5-1.0 parts of dicumyl peroxide (DCP) initiator is slowly added dropwise. After the addition is completed, the mixture is kept at 100-110°C for 2-3 hours. After the reaction is completed, the product is poured into cold ethanol to precipitate, filtered, washed 3 times with ethanol, and dried under vacuum at 60°C to constant weight to obtain epoxy modified maleic anhydride grafted polypropylene.

[0027] Maleic anhydride-grafted polypropylene was mixed with xylene solvent and heated to 100-110℃ under nitrogen protection to completely dissolve it. Glycidyl methacrylate (GMA) contains highly reactive epoxy groups, and dicumyl peroxide (DCP) acts as a free radical initiator. After the mixed solution was slowly added dropwise, DCP could trigger the grafting of GMA onto the polypropylene backbone of the maleic anhydride-grafted polypropylene, realizing the directional introduction of epoxy functional groups. After the addition was complete, the reaction was carried out at 100-110℃ for 2-3 hours to ensure sufficient grafting. After the reaction was completed, the polypropylene was precipitated with cold ethanol, filtered, washed three times with ethanol, and vacuum dried at 60℃ to constant weight to obtain epoxy-modified maleic anhydride-grafted polypropylene. Epoxy-modified maleic anhydride-grafted polypropylene can improve the mechanical properties of the central strand 6.

[0028] As one of the preferred embodiments of the present invention, the modified EPDM rubber is prepared as follows: First, 35-45 parts of polyethylene glycol 400 and 8-12 parts of maleic anhydride are mixed and stirred at 80-90°C for 2 hours to form PEG-maleic ester. Then, 25-35 parts of EPDM rubber, 1.5-2.5 parts of benzophenone and 1-2 parts of mercaptopropionic acid are added. Under a nitrogen atmosphere, the reaction system is irradiated with ultraviolet light with a wavelength of 365nm and a power of 500W for 1-2 hours. After the reaction is completed, the product is dissolved in toluene, then precipitated in ethanol, filtered and dried to obtain PEG grafted modified EPDM rubber.

[0029] First, polyethylene glycol 400 is mixed with maleic anhydride and stirred at 80-90℃ for 2 hours to form PEG-maleic ester through esterification. Then, 25-35 parts of EPDM rubber, 1.5-2.5 parts of benzophenone, and 1-2 parts of mercaptopropionic acid are added. Benzophenone acts as a UV photoinitiator. Under a nitrogen atmosphere and irradiation with 365nm wavelength and 500W power UV light, a "mercapto-alkene" click reaction is triggered between the thiol groups of mercaptopropionic acid and the remaining unsaturated double bonds in the EPDM molecular chain. Carboxyl-containing segments are introduced into EPDM rubber; the carboxyl groups further undergo esterification with PEG-maleic ester to achieve PEG segment grafting modification; after the reaction, the product is dissolved in toluene, precipitated with ethanol, filtered and dried to obtain PEG grafted modified EPDM rubber; the long PEG chain can improve the compatibility of EPDM rubber with polar polymers such as PET, enhance the flexibility of the elastomer, provide excellent elasticity for the central strand 6, and help the first filling core 1 and the second filling core 3 improve the overall performance.

[0030] As one of the preferred embodiments of the present invention, the elastic filler coating 62 comprises, by weight, the following components: 40-60 parts of acrylate emulsion, 1-2 parts of defoamer, 1-4 parts of propylene glycol, and 0.3-0.4 parts of thickener; the acrylate emulsion, by total weight, comprises 40-50 parts of methyl methacrylate, 35-40 parts of butyl acrylate, 2-3 parts of acrylic acid, 4-5 parts of glycidyl methacrylate, 2-4 parts of modified carbon nanofibers, 1-2 parts of emulsifier, 0.6-0.8 parts of pH buffer, 1.3-1.4 parts of initiator, and 80-95 parts of purified water; the defoamer is alkyl polyoxyethylene ether, the thickener is hydroxypropyl methylcellulose, the emulsifier is alkylphenol polyoxyethylene ether, the pH buffer is sodium bicarbonate, and the initiator is ammonium persulfate.

[0031] Acrylic emulsion is the main film-forming component of elastic filler coating 62. Methyl methacrylate provides the coating structural strength, butyl acrylate imparts elasticity, acrylic acid increases polarity to enhance adhesion to fiber core 61, glycidyl methacrylate promotes cross-linking to enhance coating density, modified carbon nanofibers further strengthen mechanical properties, alkyl polyoxyethylene ether defoamer eliminates bubbles generated during coating to prevent pores in the coating, propylene glycol acts as a moisturizing plasticizer to prevent cracking after coating curing and improve flexibility, hydroxypropyl methylcellulose adjusts coating viscosity to facilitate uniform coating of fiber core 61, alkylphenol polyoxyethylene ether emulsifier ensures stable dispersion of acrylic emulsion, sodium bicarbonate maintains pH stability of the reaction system, and ammonium persulfate efficiently initiates monomer polymerization. The coating formed by the synergistic action of these components can tightly coat fiber core 61 and fill the internal gaps of the first filler core 1 and the second filler core 3.

[0032] As a further technical solution of the present invention, the preparation process of the elastic filling coating includes: (a) Preparation of modified carbon nanofibers: Take 5-8 parts of carbon nanofibers and place them in a mixture of concentrated sulfuric acid / concentrated nitric acid with a volume ratio of 3:1. Stir the mixture in an oil bath at 70-80℃ for 3 hours. After filtration and washing until neutral, dry the mixture under vacuum at 60℃. (b) Preparation of acrylate emulsion: Methyl methacrylate, butyl acrylate, acrylic acid, glycidyl methacrylate, modified carbon nanofibers, emulsifier and purified water are mixed and stirred at high speed for 30 min. The temperature is raised to 85-90℃ and initiator and pH buffer are added. The reaction is kept at the temperature for 5-6 h and then cooled and discharged. (c) Coating preparation: Mix the acrylic emulsion, defoamer and propylene glycol for 10 min and let stand for 15 min to defoam. Add thickener and stir at low speed for 5 min. (d) Coating: Immerse the fiber core in the coating for 5-10 seconds, dry at 60°C for 10 minutes, repeat 3-5 times until the preset thickness is achieved, and finally cure at 120°C for 30 minutes.

[0033] In the above-mentioned preparation process of the elastic filler coating, in step (a), the concentrated sulfuric acid / concentrated nitric acid mixture is a strong oxidizing system. Carbon nanofibers are reacted in this strong oxidizing system at 70-80℃ in an oil bath for 3 hours, which introduces oxygen-containing active groups onto their surface, improving compatibility with organic components. The mixture is then filtered and washed until neutral to eliminate acid residue interference. Vacuum drying at 60℃ ensures thorough drying and structural stability of the modified carbon nanofibers. In step (b), the multi-component monomers and modified carbon nanofibers are mixed and stirred at high speed for 30 minutes to ensure uniform dispersion of the components. After adding the initiator and sodium bicarbonate, the mixture is kept at this temperature for 5-6 hours to achieve full polymerization of the monomers and form a stable acrylate emulsion. In step (c), the various additives are mixed in stages. After stirring for 10 minutes, the mixture is allowed to stand for 15 minutes to defoam and prevent pores from forming in the coating. The thickener is stirred at low speed for 5 minutes to prevent high-speed shear from damaging the emulsion structure. Step (d) involves alternating between 5-10 seconds of immersion coating on the fiber core and 10 minutes of drying at 60°C for 3-5 times, precisely controlling the coating thickness to 1 / 4-1 / 5 of the diameter of the fiber core 61. Curing at 120°C for 30 minutes promotes cross-linking and shaping of the coating, enhances its bonding with the fiber core 61, and provides excellent elastic filling effect for the first filling rope core 1 and the second filling rope core 3.

[0034] As a further technical solution of the present invention, the assembly process of the high-flexibility and high-filling-coefficient steel wire rope is as follows: (A) Rope core preparation: Prepare the first filling rope core and the second filling rope core, and spirally wind six middle layer rope cores around the outside of the first filling rope core with a tension of 5-10N. (B) Multi-layer twisting: Twelve second filler rope cores are twisted counterclockwise on the outside of the middle layer rope core. Six sets of secondary outer layer strands are first installed on the outside of the second filler rope core, and then sixty outer layer strands are twisted clockwise. The twisting angle is controlled at 12-15°. (C) Post-treatment: Heat set at 150℃ for 20 minutes, then apply anti-corrosion grease.

[0035] In the assembly process of the above-mentioned high-flexibility and high-filling-coefficient steel wire rope, step (A) first completes the preparation of the first filler core 1 and the second filler core 3. The six middle-layer cores 2 are spirally wound around the outside of the first filler core 1 with a tension of 5-10N to ensure that the winding is tight and not loose, while avoiding excessive tension that could damage the elastic structure of the first filler core 1. In step (B), the twelve second filler cores 3 are twisted to the left to fill the gaps on the outside of the middle-layer cores 2. After the six sets of secondary outer strands 4 are positioned, the sixty outer strands 5 are twisted to the right. The counter-rotation of left and right turns can offset the twisting stress of each layer. In step (C), heat setting at 150℃ for 20 minutes can eliminate the internal stress generated during the assembly process and make the structure of each layer fit more firmly. The subsequent application of anti-corrosion grease can form a protective layer on the surface of the rope and extend its service life.

[0036] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A high-flexibility and high-packing-factor steel wire rope, characterized by, It comprises a center layer, a middle layer, a secondary outer layer and an outer layer arranged from inside to outside, the center layer is a first filling rope core (1), the middle layer is six middle layer rope cores (2) arranged around the outside of the first filling rope core (1), the secondary outer layer comprises twelve second filling rope cores (3) and six groups of secondary outer layer strands (4), the twelve second filling rope cores (3) are arranged around the outside of the six middle layer rope cores, and the six groups of secondary outer layer strands (4) are annularly and equidistantly distributed between the second filling rope core (3) and the outer layer, each group of secondary outer layer strands (4) is composed of six arc-shaped arranged strands, and the outer layer is sixty outer layer strands (5) arranged around the outside of the twelve second filling rope cores (3), the first filling rope core (1) and the second filling rope core (3) are the same in structure and each comprises a center strand (6) and twenty-one fiber cores (61) arranged around the outer wall of the center strand (6), and the surface of the fiber core (61) is coated with an elastic filling coating (62).

2. The high-flexibility and high-packing-factor steel wire rope according to claim 1, characterized by The thickness of the elastic filling coating (62) is 1 / 4-1 / 5 of the diameter of the fiber core (61), the fiber core (61) is made of carbon fiber, and the secondary outer layer strand (4), the outer layer strand (5) and the middle layer rope core are steel wire ropes made of galvanized steel wire.

3. The high-flexibility and high-packing-factor steel wire rope according to claim 1, characterized by, The preparation process of the center strand (6) is as follows: PET, modified maleic anhydride grafted polypropylene and modified EPDM are mixed, and then they are melt blended at 240-260 DEG C for 10 min; zinc stearate and antioxidant 168 are added and stirred for 5 min to obtain a spinning material; the spinning material is fed into a spinning machine and spun at 260-280 DEG C, and then the center strand (6) is prepared after bunching, drawing at a speed of 500-800 m / min and crimping.

4. The high-flexibility and high-packing-factor steel wire rope according to claim 3, characterized by The preparation method of the modified maleic anhydride grafted polypropylene is as follows: 50-70 parts of maleic anhydride grafted polypropylene and 90-110 parts of dimethylbenzene solvent are mixed, heated to 100-110 DEG C under nitrogen protection to make them completely dissolved, then a mixed solution containing 5-10 parts of glycidyl methacrylate (GMA) and 0.5-1.0 parts of dicumyl peroxide (DCP) initiator is slowly added, after the addition is completed, the reaction is carried out at 100-110 DEG C for 2-3 hours, after the reaction is completed, the product is precipitated in cold ethanol, filtered and washed with ethanol for 3 times, and then dried at 60 DEG C under vacuum to constant weight to obtain the epoxy modified maleic anhydride grafted polypropylene.

5. The high-flexibility and high-packing-factor steel wire rope according to claim 3, wherein The preparation method of the modified EPDM is as follows: 35-45 parts of polyethylene glycol 400 and 8-12 parts of maleic anhydride are mixed and stirred at 80-90 DEG C for 2 hours to form PEG-maleate, then 25-35 parts of EPDM, 1.5-2.5 parts of benzophenone and 1-2 parts of mercaptopropionic acid are added, the reaction system is irradiated by ultraviolet light with a wavelength of 365 nm and a power of 500 W for 1-2 hours under nitrogen atmosphere, after the reaction is completed, the product is dissolved in toluene, precipitated in ethanol, filtered and dried to obtain the PEG grafted modified EPDM.

6. The high-flexibility and high-packing-factor steel wire rope according to claim 1, wherein The elastic filling coating (62) is composed of, by weight fraction, 40-60 parts of an acrylate emulsion, 1-2 parts of an antifoaming agent, 1-4 parts of propylene glycol, and 0.3-0.4 parts of a thickening agent; the acrylate emulsion contains, by total weight, 40-50 parts of methyl methacrylate, 35-40 parts of butyl acrylate, 2-3 parts of acrylic acid, 4-5 parts of glycidyl methacrylate, 2-4 parts of modified carbon nanofibers, 1-2 parts of an emulsifier, 0.6-0.8 parts of a pH buffer, 1.3-1.4 parts of an initiator, and 80-95 parts of purified water; the antifoaming agent is an alkyl polyoxyethylene ether, the thickening agent is hydroxypropyl methyl cellulose, the emulsifier is an alkyl phenol polyoxyethylene ether, the pH buffer is sodium bicarbonate, and the initiator is ammonium persulfate.

7. The high-flexibility and high-packing-factor steel wire rope according to claim 6, characterized in that, The preparation process of the elastic filling coating (62) comprises: (a) Preparation of modified carbon nanofibers: 5-8 parts of carbon nanofibers are placed in a concentrated sulfuric acid / concentrated nitric acid mixture with a volume ratio of 3:1, and stirred in an oil bath at 70-80°C for 3h, and then washed to neutral and vacuum dried at 60°C after filtration; (b) Preparation of acrylate emulsion: methyl methacrylate, butyl acrylate, acrylic acid, glycidyl methacrylate, modified carbon nanofibers, emulsifier, and purified water are mixed and stirred at high speed for 30min, and then the initiator and pH buffer are added after the temperature is raised to 85-90°C, and the reaction is carried out for 5-6h, and then the temperature is lowered to discharge the product; (c) Preparation of coating: the acrylate emulsion, antifoaming agent, and propylene glycol are mixed and stirred for 10min, and then left to stand for 15min to remove foam, and then the thickening agent is added and stirred at low speed for 5min; (d) Coating: the fiber core (61) is immersed in the coating for 5-10 seconds, and then dried at 60°C for 10min, and the process is repeated for 3-5 times until the preset thickness is reached, and finally cured at 120°C for 30min.

8. The high-flexibility and high-packing-factor steel wire rope according to claim 1, wherein The assembly process of the high-flexibility and high-filling-factor steel wire rope comprises: (A) Core preparation: a first filling core (1) and a second filling core (3) are prepared, and six middle layer cores are spirally wound outside the first filling core (1) with a tension of 5-10N; (B) Multi-layer stranding: twelve second filling cores (3) are left-handed stranded outside the middle layer cores, and six groups of secondary outer layer strands (4) are installed outside the second filling cores (3), and then sixty outer layer strands (5) are right-handed stranded, and the stranding angle is controlled at 12-15°; (C) Post-processing: heat setting at 150°C for 20min, and then coating with anticorrosive grease.

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