Wire and Cable Industry: Precision Control and Efficiency Improvement of Twin-screw Extruders

In the field of modern industrial manufacturing, wires and cables serve as critical carriers for power transmission and information communication. Their performance and quality are directly related to the stability, safety, and reliability of the entire system. With the continuous advancement of technology and the growing market demand, the wire and cable industry is facing unprecedented challenges and opportunities. Against this backdrop, twin-screw extruders, as an efficient and precise plastic processing equipment, play a particularly important role in the production of insulation layers and sheaths for wires and cables. There are many types of materials for insulating layers and sheaths, but most are primarily PE and PVC materials. PE cable materials are used for outdoor and underground cables, while PVC cable materials are used for household appliances and low-voltage cables. The cable material is based on resin as the carrier, with many additives such as flame retardants and antioxidants added to enhance its weather resistance and prevent it from burning.
This article will delve into the precision control capabilities of twin-screw extruders in the wire and cable industry and how they significantly improve production efficiency, aiming to provide useful references for research and practice in related fields.

Basic Principles and Advantages of Granuwel Twin-screw Extruders

The Granuwel twin-screw extruder is an advanced plastic processing equipment that uses two intermeshing screws to mix, plasticize, and continuously extrude molded plastic raw materials through rotational movement. Compared with traditional single-screw extruders, twin-screw extruders have stronger shear force, more uniform mixing effects, and higher plasticization efficiency. These characteristics make them especially suitable for granulating insulating layers and sheath materials for wires and cables, ensuring material uniformity and stability, thereby improving the overall performance of wires and cables.

Specifically, the screw design of the Granuwel twin-screw extruder allows the raw materials to undergo intense shear action during the extrusion process. This shear action not only helps to improve the degree of material plasticization but also helps to eliminate small molecular materials and impurities produced during the plasticization process, thus obtaining a more uniform and dense product. Additionally, the mixing effect of twin-screw extruders is also more outstanding. They can fully mix different components of materials together to form a uniform mixture, which is crucial for the production of insulating layers and sheaths for wires and cables. Moreover, the plasticization efficiency of twin-screw extruders is higher. They can process a large amount of materials in a short time, thereby significantly improving production efficiency.

In the wire and cable industry, selecting the appropriate cutting method for twin-screw extruders is crucial for production efficiency and product quality. Below are several common cutting methods and their characteristics, as well as how they apply to the wire and cable industry:

1. Water ring hot cutting system: Water ring hot cutting system is used for granulating cross-linked cable materials based on PE. It is a common hot cutting method that involves extruding molten plastic strips from the extruder and immediately cutting them into particles with rotating blades. These particles are then sent to a container filled with circulating water for cooling and solidification. The advantage of Water ring hot cutting system lies in its ability to quickly and effectively cool the particles, maintaining their shape and size stability. Additionally, Water ring hot cutting system provides uniform cooling effects. To ensure the stability of wire and cable extrusion, cable material particles dried by a dehydrator need to be dehumidified and dried through a fluidized bed and sealed for storage.

2. Water cooling strands pelletizing system: Used for granulating cable sheath materials based on PE, Water cooling strands pelletizing system is a traditional cutting method that involves extruding molten plastic strips directly into a cooling water tank after exiting the extruder for cooling and solidification. The cooled plastic strips are then cut into particles by a granulator. The advantages of draw bar cold cutting include simple equipment, low cost, and suitability for various plastic materials. Draw bar cold cutting can provide relatively stable particle shapes and sizes, helping to improve product consistency and quality. However, due to the longer cooling time required, the production efficiency of draw bar cold cutting is relatively low. To improve production efficiency, optimizing the design of the cooling water tank or using more efficient cooling media to shorten the cooling time can be considered.

1. 3. Air cooling hot cutting system: Used for granulating PVC cable sheath materials and PE halogen-free flame-retardant cable materials.

The characteristic of the dual-stage machine lies in its unique structural design. The first stage is a GTE high-speed co-rotating parallel twin-screw extruder, which utilizes the high dispersion and strong shear of the twin screws to rapidly and fully complete the plasticization and dispersion of materials. At the same time, since the screw has a modular structure, it can adjust the screw combination according to different materials to achieve the best mixing state of materials. The second stage is a GDE low-speed single-screw extruder used for low-temperature extrusion. Due to the deep groove structure of the single screw, it helps stabilize the pressure during the extrusion process. The single screw barrel is equipped with heating and cooling, allowing precise control of the extrusion temperature to avoid excessive temperature decomposition of the melt. The dual-stage extruder combines the high speed, strong mixing characteristics of the twin screws with the low speed, low temperature, weak shear characteristics of the single screw, maximizing equipment advantages and significantly improving production efficiency. The two machines are placed vertically to save space and provide a continuous production line layout. It is widely used in various thermally sensitive material systems and large volume swing operations, such as PVC, XLPE, halogen-free flame-retardant cables, shielding materials, high concentration carbon black, and rubber post-dehydration processing operations.

Application of Precision Control Capabilities in Wire and Cable Production

1. Temperature Control: Temperature is one of the critical factors affecting the performance of wire and cable insulation layers and sheaths. Too high or too low temperatures can lead to a decline in material performance or defects. Therefore, precise control of temperature during the extrusion process is vital for ensuring product quality. Twin-screw extruders are equipped with advanced temperature control systems that can monitor and regulate the temperature of each segment of screws and dies in real time. By precisely controlling the temperature, it ensures that the material remains in optimal condition during the extrusion process, avoiding quality issues caused by temperature fluctuations. Additionally, precise temperature control also helps reduce energy consumption and lower production costs.

2. Control of Mixing Ability: The structure of twin screws is a modular screw structure, which can adjust the screw combination according to different material characteristics to achieve the optimal screw structure. This ensures that all aspects of cable materials reach their best performance, such as PVC material being thermally sensitive. Too strong shear force can cause it to overheat and decompose. Other additives require more engagement blocks to evenly disperse them into the PVC base material, which requires the screw structure to maximize strengths and minimize weaknesses to achieve the best effect.

Manifestation of Efficiency Improvement

1. Improving Production Efficiency: The high plasticization and mixing capabilities of twin-screw extruders allow them to process a large amount of materials in a short time. Compared with traditional extruders, twin-screw extruders can significantly shorten the production cycle and improve production efficiency. Additionally, precise control capabilities can also reduce the rate of waste products and rework during production, further reducing production costs. By optimizing production processes and improving equipment utilization, enterprises can achieve higher capacity and lower production costs.

2. Improving Product Quality: By precisely controlling parameters such as temperature and screw structure, twin-screw extruders can ensure the uniformity and stability of wire and cable insulating layers and sheaths. This uniformity and stability not only help extend the lifespan of wires and cables but also reduce maintenance and replacement costs due to quality issues. High-quality products can meet the market’s demand for high-performance, high-reliability wires and cables, enhancing the market competitiveness of enterprises.

3. Enhancing Market Competitiveness: In fierce market competition, having efficient and stable production equipment is key for enterprises to gain market share. The precision control capabilities and efficiency improvement advantages of twin-screw extruders in wire and cable production can help enterprises improve product quality, reduce production costs, and shorten delivery cycles. These advantages will put enterprises in a favorable position in market competition, enhancing market competitiveness.

In conclusion, the precision control capabilities of twin-screw extruders in the production of insulating layers and sheaths for wires and cables, along with the resulting improvements in production efficiency, are significant for enhancing the overall level and competitiveness of the wire and cable industry. With continuous technological advancements and changing market demands, twin-screw extruders will play an increasingly important role in the wire and cable industry. In the future, we look forward to seeing more innovative technology applications and more efficient, environmentally friendly production methods emerge, jointly promoting the continuous development and prosperity of the wire and cable industry.