In various electrical connection and industrial application scenarios, braided wires have always occupied an important position due to their excellent electrical performance, mechanical strength, and flexibility. With the continuous evolution of technology and the increasing diversification of application demands, hollow and flattened braided wires, as special members of the braided wire family, are gradually emerging. Relying on their unique structural designs and performance advantages, they bring innovative solutions to many fields.
I. Structure and Principle
Hollow Braided Wires
As the name suggests, hollow braided wires have a hollow internal structure. This structure is usually achieved through a specific braiding process, where multiple strands of wires are braided around a central hollow area. In actual production, metals with good electrical conductivity such as copper and aluminum are commonly used as wire materials. Taking copper hollow braided wires as an example, first, copper rods undergo a wire-drawing process to be pulled into thin copper wires of the required diameter. Then, using professional braiding equipment, these copper wires are braided around a pre-set hollow mold according to specific braiding angles and densities. After the braiding is completed, the hollow mold is removed, and the hollow braided wire is obtained. The hollow structure enables it to significantly reduce its own weight while ensuring certain electrical performance, which has obvious advantages in weight-sensitive application scenarios.
Flattened Braided Wires
Flattened braided wires are made by subjecting traditional braided wires with circular cross-sections to a mechanical flattening process, turning their cross-sections into a flat shape. The production process generally involves, after the braiding of the braided wire is completed, feeding it into a flattening device equipped with a mold of a specific shape. The design of the mold is customized according to the required thickness and width of the flattened wire. The device applies pressure to make the braided wire undergo plastic deformation in the mold, thereby obtaining a flat cross-sectional shape. In some applications requiring high precision, a subsequent finishing process is also performed on the flattened braided wire to ensure its dimensional accuracy and surface quality. This flat structure changes the distribution of the electrical and mechanical properties of the braided wire, endowing it with unique advantages in certain application scenarios.
II. Performance Advantages
Hollow Braided Wires
Lightweight: The hollow structure directly reduces the amount of material used, resulting in a significant reduction in overall weight. In the aerospace field, the electrical wiring on aircraft has extremely strict weight requirements. The use of hollow braided wires can effectively reduce the overall weight of the aircraft, thereby lowering energy consumption, improving flight performance, and extending endurance. For example, in the electronic system of a satellite, the use of hollow braided wires for electrical connections can reduce the satellite's weight without affecting electrical performance, thereby lowering launch costs.
Electromagnetic Shielding Property: The hollow structure helps to form a unique electromagnetic shielding effect. When there is external electromagnetic interference, the metal shell of the hollow braided wire can reflect and absorb the interference signals, thereby protecting the internally transmitted signals from interference. In some electronic equipment with high requirements for electromagnetic compatibility, such as medical magnetic resonance imaging (MRI) equipment and radio frequency modules of communication base stations, the electromagnetic shielding property of hollow braided wires can ensure the stable operation of the equipment and avoid misdiagnosis or communication failures caused by signal interference.
Heat Dissipation Advantage: The hollow structure increases the space for air circulation, which is conducive to heat dissipation. In some occasions with high-current transmission, such as the connection lines of battery packs in electric vehicles, heat is generated when current passes through. The good heat dissipation performance of hollow braided wires can effectively reduce the temperature of the lines, improve the safety and reliability of the system, and extend the service life of the lines.
Flattened Braided Wires
Higher Space Utilization: The flat cross-sectional shape allows for tighter arrangement during wiring, saving space. In the wiring of motherboards with compact internal space in electronic equipment, flattened braided wires can realize more electrical connections in a limited space, meeting the development trend of miniaturization and integration of electronic equipment. For example, in the motherboard design of a smartphone, the use of flattened braided wires to connect various chips and electronic components can effectively reduce the size of the motherboard and free up more space for other functional modules.
Improved Electrical Performance: Compared with circular braided wires, flattened braided wires have an increased surface area in the flat direction, which makes the current distribution more uniform and reduces resistance. In the field of power transmission, power transmission lines using flattened braided wires can reduce power loss and improve transmission efficiency. According to relevant research, under the same current transmission conditions, the line resistance of flattened braided wires can be reduced by approximately [X]% compared with circular braided wires, thereby effectively saving energy.
Enhanced Mechanical Stability: The flat structure increases the contact area between the braided wire and other components. When subjected to external forces, it can better disperse stress and improve mechanical stability. In the complex wiring environment of an automobile engine compartment, the vibration of the engine and the jolting of the vehicle during driving will cause continuous external impact on the electrical lines. Relying on its good mechanical stability, flattened braided wires can effectively resist these external forces, reduce the occurrence of faults such as line loosening and breakage, and ensure the stable operation of the automobile electrical system.
III. Application Fields
Hollow Braided Wires
Aerospace: As mentioned earlier, they are widely used in the electrical systems of aircraft, including the avionics systems of airplanes and the connection of electronic equipment in satellites. Their lightweight and electromagnetic shielding properties are crucial for ensuring the reliable operation of aircraft under complex electromagnetic environments and strict weight constraints.
Medical Equipment: In some high-precision medical testing equipment, such as magnetic resonance imaging (MRI) equipment, hollow braided wires are used to connect various electronic components of the equipment. Their good electromagnetic shielding performance can effectively eliminate external electromagnetic interference, ensuring that the equipment obtains accurate and clear images and providing a reliable basis for doctors' diagnosis.
New Energy Vehicles: In the connection lines between the battery management system, motor controller, and battery pack of electric vehicles, hollow braided wires, with their heat dissipation advantages and lightweight characteristics, help to improve the performance and safety of the battery system and extend the cruising range of electric vehicles.
Flattened Braided Wires
Electronic Equipment Manufacturing: In the wiring of motherboards of various consumer electronic products such as smartphones, tablets, and laptops, the high space utilization and good electrical performance of flattened braided wires make them ideal electrical connection materials, which can meet the continuous pursuit of miniaturization and high performance in electronic equipment.
Power Transmission and Distribution: In medium and low-voltage power transmission lines and equipment such as power distribution boxes, the low-resistance characteristic of flattened braided wires can reduce line loss and improve the economy of power transmission; their flat structure also facilitates wiring and installation in a limited space, improving construction efficiency.
Industrial Automation: In equipment such as industrial robots and automated production lines, electrical lines need to be bent and moved frequently. The good flexibility and mechanical stability of flattened braided wires can ensure the long-term stable operation of the lines in complex motion environments and reduce production interruptions caused by line faults.
IV. Manufacturing Process and Quality Control
Hollow Braided Wires
In terms of the manufacturing process, in addition to the aforementioned wire-drawing and braiding links, the design and manufacturing precision of the hollow mold are extremely demanding. The dimensional accuracy and surface roughness of the mold directly affect the internal hollow shape and surface quality of the hollow braided wire. In terms of quality control, strict testing of the purity and performance of raw materials is required to ensure that the metal wires have good electrical conductivity and mechanical performance. During the braiding process, online monitoring equipment is used to real-time monitor parameters such as braiding angle and density to ensure the consistency of braiding quality. During the finished product inspection, non-destructive testing methods such as X-ray flaw detection are used to check for defects inside the hollow structure; at the same time, electrical performance tests, including the measurement of parameters such as resistance and inductance, are conducted to ensure that they meet relevant standards.
Flattened Braided Wires
In the manufacturing process, the pressure control of the flattening equipment and the precision of the mold are crucial. Excessive pressure may cause excessive deformation or even breakage of the braided wire, while insufficient pressure cannot achieve the required flat size. Therefore, it is necessary to precisely control the equipment pressure and regularly maintain and calibrate the mold. In terms of quality control, the original quality of the braided wire is strictly checked before flattening, including the uniformity of wire diameter and braiding quality. After flattening, 100% inspection of the dimensional accuracy of the flattened wire is conducted to ensure that its thickness and width meet the design requirements; at the same time, surface quality inspection is performed to check for defects such as scratches and uneven deformation. Bending fatigue tests are also conducted to simulate its bending situation in actual applications and evaluate its mechanical reliability.
V. Challenges and Development Trends
Challenges
Cost Issue: The manufacturing process of hollow and flattened braided wires is relatively complex, and the requirements for equipment and molds are high, resulting in a higher production cost compared with traditional braided wires. This limits their large-scale promotion in some cost-sensitive application fields to a certain extent.
Performance Optimization Difficulties: Although hollow and flattened braided wires have advantages in certain performance aspects, they may have shortcomings in other aspects. For example, the mechanical strength of hollow braided wires may be inferior to that of solid braided wires in some cases, requiring further optimization of materials and structural design to balance various performance aspects; the change law of the mechanical properties of flattened braided wires in the flat direction during bending is relatively complex, and how to ensure their long-term reliability under complex working conditions still requires in-depth research.
Development Trends
Material Innovation: Develop new high-performance and low-cost materials, such as high-strength and high-conductivity alloy materials, to improve the comprehensive performance of hollow and flattened braided wires while reducing production costs. For example, exploring materials based on nanotechnology, and enhancing the strength and conductivity of metal materials through the addition of nanoparticles, is expected to further improve the performance of braided wires without increasing costs excessively.
Intelligent Manufacturing Process: Introduce advanced technologies such as artificial intelligence and big data to realize intelligent control of the manufacturing process. Through the collection and analysis of a large amount of data in the production process, equipment parameters are adjusted in real time, the production process is optimized, and the stability of product quality and production efficiency are improved. For example, using machine learning algorithms to predict the optimal flattening pressure and braiding parameters based on raw material characteristics and real-time production data, ensuring that product quality always meets standards.
Expansion of Application Fields: With the continuous development of science and technology, emerging industries have put forward higher requirements for the performance of electrical connection materials, bringing new application opportunities for hollow and flattened braided wires. In the construction of 5G communication base stations, a large number of electrical connection materials with excellent electromagnetic shielding performance and space utilization are needed, and hollow and flattened braided wires are expected to be widely used in this field; in the new energy field, with the continuous expansion of solar and wind power generation scales, the demand for efficient and reliable power transmission lines increases, and the low-resistance and lightweight advantages of hollow and flattened braided wires will enable them to play an important role in new energy power transmission.
With their unique structural designs, hollow and flattened braided wires demonstrate many performance advantages that traditional braided wires do not have and are widely used in many fields. Although they currently face some challenges, with the continuous advancement of materials science and manufacturing technology, they have broad development prospects and will play a more important role in future electrical connections and industrial applications, promoting the continuous innovation and development of related industries.
