Publish Time: 2026-03-24 Origin: Site
In the grand narrative of modern industry, rubber products are ubiquitous—from drive belts under the hood of cars, to high-pressure hoses on deep-sea drilling platforms, to tires in daily life. Yet few people notice that inside these seemingly flexible rubber products lies a “reinforced steel skeleton” silently bearing the brunt of the work. This skeleton is rubber cord.
Rubber cord, as the name implies, refers to the cord materials used to reinforce rubber products such as hoses and conveyor belts. It acts like the rebar in concrete, endowing rubber products with critical properties such as high strength, low elongation, and fatigue resistance, enabling them to withstand immense pressure, impact, and repeated flexing. Without it, rubber would remain a soft and useless substance.
Based on application scenarios and performance requirements, rubber cords are mainly divided into two categories: organic fiber cords and steel wire cords.
Made from high-strength synthetic fibers such as polyester and aramid, organic fiber cords undergo processes like twisting and dipping. The greatest advantages of this type are light weight, high strength, corrosion resistance, and a degree of flexibility.
Polyester Cord: This is one of the most commonly used types. It features high initial modulus, high adhesion strength, excellent fatigue resistance, and good dimensional stability. It is widely used as a reinforcing material in traditional transmission belts such as synchronous belts, V-ribbed belts, wrapped V-belts, and in ordinary and high-pressure hoses. In recent years, the global market for dipped polyester cords has maintained steady growth, with the market size reaching approximately 1.09 billion yuan in 2024, projected to hit 1.34 billion yuan by 2031.
Aramid Cord: If polyester cord is an “excellent student,” aramid cord is the “top performer.” This high-performance composite material is known as the “new high-end reinforcing material for the rubber hose and belt industry.” Domestic companies like Qingdao Tianding Lacing Co., Ltd. have secured significant positions in this field. Their aramid dipped cord for rubber V-belts ranked first in the domestic market share in 2019 and third globally, with products exported to countries such as Germany, the USA, and India. Compared to standard steel wire rope, aramid cord offers advantages like superior stability and reinforcement, making it particularly suitable for demanding applications like agricultural belts, V-belts, and transmission belts.
When extremely high pressure resistance is required, steel wire rope is the only option. These products are governed by national standards like GB/T 12756-2018 “Galvanized Steel Wire Ropes for High-Pressure Rubber Hoses.” The manufacturing process for steel wire rope is extremely complex. Taking a 0.71mm large-diameter hose wire as an example, it starts with a 5.50mm C82DA wire rod and goes through dozens of processes, including pre-treatment drawing, heat treatment, electroplating, and wet drawing, achieving a breaking force as high as 1020-1045N.
In recent years, driven by demands from cutting-edge sectors like offshore oil and gas extraction, steel wire rope for rubber hoses has been trending towards larger diameters and higher strength. For instance, the domestically produced 1x24DW structural steel wire rope has been used in key equipment for the “Offshore Oil 981” drilling platform, which won the National Science and Technology Progress Special Award.
Whether polyester or aramid cord, they must undergo a critical process: dipping treatment. Untreated fibers have smooth surfaces and chemically differ significantly from rubber, making direct bonding impossible. Dipping is the “magic” that solves this problem.
Modern dipping processes typically use a combination of a “first dip” and a “second dip”:
First Dip: The cord is first immersed in a dip solution containing reactive components such as blocked isocyanates. These small molecules can penetrate deep into the cord. During subsequent high-temperature drying, they undergo a cross-linking reaction, enhancing the cord’s internal strength.
Second Dip: The cord is then passed through an RFL (Resorcinol-Formaldehyde-Latex) dip solution. This forms a dense film on the surface of the cord that has excellent affinity with rubber.
Through this dual treatment, the active components in the dip solutions chemically react with both the cord and the rubber, forming strong chemical bonds. This ensures that the rubber and cord do not delaminate during long-term dynamic use.
China has become a significant global manufacturing hub for rubber cords. From being entirely dependent on imports in the early days to fully substituting imports by 1982, and now to becoming a competitive player in the global market, the Chinese rubber cord industry has undergone a remarkable journey. The country has fostered a number of internationally competitive leading enterprises, such as Qingdao Tianding Lacing Co., Ltd., Zhejiang Unifull Industrial Co., Ltd., and Jiangsu Fasten Co., Ltd. Their products not only meet domestic demand but are also exported in large quantities to markets in Europe, America, and Southeast Asia.
Looking ahead, the rubber cord industry is expected to exhibit the following trends:
High Performance: Driven by the automotive industry’s push for lightweighting and the advancement of deep-sea oil and gas extraction, demand for high-strength, high-modulus fibers like aramid will continue to grow.
Environmental Friendliness: The industry is actively researching water-based adhesives to reduce environmental pollution associated with traditional solvent-based processes.
Cost-Effectiveness: There is a push to develop new steel wire rope structures with better performance and lower cost, such as the 1x24DW structure, to meet market demands for cost reduction and efficiency.
From a slender fiber to a tough steel wire, rubber cord may remain hidden within rubber products, yet it supports the backbone of modern industry. It is not only a microcosm of progress in materials science but also a critical yardstick for measuring a country’s industrial base. As technology continues to advance, this “cord” hidden within rubber will undoubtedly weave an even broader blueprint for industry.
In the grand narrative of modern industry, rubber products are ubiquitous—from drive belts under the hood of cars, to high-pressure hoses on deep-sea drilling platforms, to tires in daily life. Yet few people notice that inside these seemingly flexible rubber products lies a “reinforced steel skeleton” silently bearing the brunt of the work. This skeleton is rubber cord.
Rubber cord, as the name implies, refers to the cord materials used to reinforce rubber products such as hoses and conveyor belts. It acts like the rebar in concrete, endowing rubber products with critical properties such as high strength, low elongation, and fatigue resistance, enabling them to withstand immense pressure, impact, and repeated flexing. Without it, rubber would remain a soft and useless substance.
Based on application scenarios and performance requirements, rubber cords are mainly divided into two categories: organic fiber cords and steel wire cords.
Made from high-strength synthetic fibers such as polyester and aramid, organic fiber cords undergo processes like twisting and dipping. The greatest advantages of this type are light weight, high strength, corrosion resistance, and a degree of flexibility.
Polyester Cord: This is one of the most commonly used types. It features high initial modulus, high adhesion strength, excellent fatigue resistance, and good dimensional stability. It is widely used as a reinforcing material in traditional transmission belts such as synchronous belts, V-ribbed belts, wrapped V-belts, and in ordinary and high-pressure hoses. In recent years, the global market for dipped polyester cords has maintained steady growth, with the market size reaching approximately 1.09 billion yuan in 2024, projected to hit 1.34 billion yuan by 2031.
Aramid Cord: If polyester cord is an “excellent student,” aramid cord is the “top performer.” This high-performance composite material is known as the “new high-end reinforcing material for the rubber hose and belt industry.” Domestic companies like Qingdao Tianding Lacing Co., Ltd. have secured significant positions in this field. Their aramid dipped cord for rubber V-belts ranked first in the domestic market share in 2019 and third globally, with products exported to countries such as Germany, the USA, and India. Compared to standard steel wire rope, aramid cord offers advantages like superior stability and reinforcement, making it particularly suitable for demanding applications like agricultural belts, V-belts, and transmission belts.
When extremely high pressure resistance is required, steel wire rope is the only option. These products are governed by national standards like GB/T 12756-2018 “Galvanized Steel Wire Ropes for High-Pressure Rubber Hoses.” The manufacturing process for steel wire rope is extremely complex. Taking a 0.71mm large-diameter hose wire as an example, it starts with a 5.50mm C82DA wire rod and goes through dozens of processes, including pre-treatment drawing, heat treatment, electroplating, and wet drawing, achieving a breaking force as high as 1020-1045N.
In recent years, driven by demands from cutting-edge sectors like offshore oil and gas extraction, steel wire rope for rubber hoses has been trending towards larger diameters and higher strength. For instance, the domestically produced 1x24DW structural steel wire rope has been used in key equipment for the “Offshore Oil 981” drilling platform, which won the National Science and Technology Progress Special Award.
Whether polyester or aramid cord, they must undergo a critical process: dipping treatment. Untreated fibers have smooth surfaces and chemically differ significantly from rubber, making direct bonding impossible. Dipping is the “magic” that solves this problem.
Modern dipping processes typically use a combination of a “first dip” and a “second dip”:
First Dip: The cord is first immersed in a dip solution containing reactive components such as blocked isocyanates. These small molecules can penetrate deep into the cord. During subsequent high-temperature drying, they undergo a cross-linking reaction, enhancing the cord’s internal strength.
Second Dip: The cord is then passed through an RFL (Resorcinol-Formaldehyde-Latex) dip solution. This forms a dense film on the surface of the cord that has excellent affinity with rubber.
Through this dual treatment, the active components in the dip solutions chemically react with both the cord and the rubber, forming strong chemical bonds. This ensures that the rubber and cord do not delaminate during long-term dynamic use.
China has become a significant global manufacturing hub for rubber cords. From being entirely dependent on imports in the early days to fully substituting imports by 1982, and now to becoming a competitive player in the global market, the Chinese rubber cord industry has undergone a remarkable journey. The country has fostered a number of internationally competitive leading enterprises, such as Qingdao Tianding Lacing Co., Ltd., Zhejiang Unifull Industrial Co., Ltd., and Jiangsu Fasten Co., Ltd. Their products not only meet domestic demand but are also exported in large quantities to markets in Europe, America, and Southeast Asia.
Looking ahead, the rubber cord industry is expected to exhibit the following trends:
High Performance: Driven by the automotive industry’s push for lightweighting and the advancement of deep-sea oil and gas extraction, demand for high-strength, high-modulus fibers like aramid will continue to grow.
Environmental Friendliness: The industry is actively researching water-based adhesives to reduce environmental pollution associated with traditional solvent-based processes.
Cost-Effectiveness: There is a push to develop new steel wire rope structures with better performance and lower cost, such as the 1x24DW structure, to meet market demands for cost reduction and efficiency.
From a slender fiber to a tough steel wire, rubber cord may remain hidden within rubber products, yet it supports the backbone of modern industry. It is not only a microcosm of progress in materials science but also a critical yardstick for measuring a country’s industrial base. As technology continues to advance, this “cord” hidden within rubber will undoubtedly weave an even broader blueprint for industry.
A: Rubber cord is a reinforcing material used in rubber products such as hoses, drive belts, and conveyor belts. It is typically made from high-strength fibers (such as polyester or aramid) or steel wire. Its role is similar to that of rebar in concrete—it provides rubber products with high strength, low elongation, fatigue resistance, and impact resistance, enabling them to withstand high pressure, repeated flexing, and dynamic loads.
A: The key difference lies in surface treatment. Rubber cord must undergo a specialized dipping treatment to form a coating on its surface that has good chemical affinity with rubber. Ordinary rope lacks this treatment and cannot bond firmly with rubber. Embedding untreated rope directly into rubber would lead to delamination, blistering, and other failure issues.
A: The choice depends on the application scenario:
| Comparison | Organic Fiber Cord | Steel Wire Cord |
|---|---|---|
| Weight | Light | Heavy |
| Strength | High | Extremely high |
| Elongation | Relatively low | Extremely low |
| Corrosion Resistance | Excellent | Requires galvanization |
| Flexibility | Good | Moderate |
| Typical Applications | V-belts, synchronous belts, ordinary hoses | High-pressure hoses, hydraulic hoses, deep-sea risers |
A simple rule of thumb: choose organic fiber when lightweight, corrosion resistance, and flexible transmission are priorities; choose steel wire when extreme high-pressure resistance is required.
A: No, it cannot. Untreated fibers have a smooth surface and low polarity, making them chemically incompatible with rubber. A strong bond cannot form between them. After dipping treatment, active components in the dip solution form a "bridge" layer on the cord's surface, creating chemical cross-linking reactions with the rubber. This ensures that the rubber and cord do not delaminate or slip during dynamic use.
A: RFL stands for Resorcinol-Formaldehyde-Latex. It is one of the core formulations used in rubber cord dipping treatment. It is a mixture of a resorcinol-formaldehyde resin and latex. The RFL layer forms a dense film on the cord's surface that bonds well with the fibers while also forming a strong bond with various types of rubber (such as natural rubber, nitrile rubber, and neoprene).
A: Each has its advantages and disadvantages. There is no absolute "better"—it depends on performance requirements.
Polyester Cord: Cost-effective, moderate modulus, stable adhesion, suitable for most conventional drive belts and hoses.
Aramid Cord: Higher strength, higher modulus, better heat resistance, but more expensive. Suitable for demanding conditions such as high loads, high speeds, and high temperatures—applications include agricultural belts, automotive V-ribbed belts, and heavy-duty conveyor belts.
Think of it this way: polyester is the "cost-effective choice," while aramid is the "high-performance flagship option."
Dipped Fabric Dipped Soft/Stiff Cord Hose Yarn Tyre Cord Fabric
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