Comparison Between Continuous Extrusion Machines and Traditional Extrusion Processes
In the field of metal processing, extrusion is an important forming method. Traditional extrusion processes have long dominated the industry, yet the advent of continuous extrusion machines has brought about a new revolution with technological advancements. Today, we will conduct an in-depth comparison between continuous extrusion machines and traditional extrusion processes to explore their respective characteristics, advantages and disadvantages.
Traditional Extrusion Processes
With a long history, traditional extrusion processes mainly include direct extrusion, indirect extrusion and hydrostatic extrusion. Taking direct extrusion as an example, the extrusion stem pushes the billet forward in the extrusion container, and significant friction exists between the billet and the inner wall of the container, leading to uneven metal flow. This results in inhomogeneous microstructure and properties of extruded products, increased energy consumption, accelerated wear of molds due to frictional heating, and restricted extrusion speed. Although indirect extrusion and hydrostatic extrusion have improved on direct extrusion, they still share an inherent flaw: discontinuity in production. After extruding a single billet, operations such as separating the residual billet and refilling with a new one are required, which limits efficiency improvement and product length—the typical processed length is no more than 30-50 meters.
Continuous Extrusion Machines
Continuous extrusion machines are an innovative achievement in extrusion forming technology, whose working principle cleverly utilizes the frictional force between deformed metal and tools. A continuous extrusion machine is mainly composed of an extrusion wheel with concave grooves, an extrusion shoe, a dummy block and an extrusion die. Driven by the drive shaft, the extrusion wheel rotates; when the billet is fed into the wheel groove, the frictional force from the groove wall pulls the billet forward continuously. The groove seal block of the extrusion shoe cooperates with the extrusion wheel to form a cavity similar to an extrusion container, and the dummy block seals the outlet end of the cavity, forcing the metal to flow out only through the extrusion die. Continuous extrusion can be achieved as long as billets are fed continuously, enabling the production of coiled products with a length of thousands or even tens of thousands of meters for convenient transportation.
A Comparative Analysis
Advantages of Continuous Extrusion Machines Over Traditional Extrusion Processes
High material utilization rate
Continuous extrusion machines use continuous casting and rolling wire rods as raw materials without extrusion residuals, achieving a material utilization rate of up to 95%—a substantial increase compared with traditional processes.
Remarkable energy saving
Continuous extrusion machines rely on frictional heating to raise the temperature, eliminating the need for external heating and saving a large amount of energy.
Simplified processes & improved efficiency
Taking pipe processing as an example, the continuous extrusion process can omit more than 15 procedures compared with traditional pipe processing methods. The product yield rate can reach over 90%, while that of traditional methods for the same type of pipes is only about 50%. This significantly shortens the production cycle, reduces costs and enhances market competitiveness.
Strong billet adaptability
A variety of billets are applicable, including wire rods, granular and even liquid raw materials. The machine can also directly utilize metal scrap for recycling, turning waste into valuable resources.
Continuous production capability
Uninterrupted production is achievable with no downtime, making it suitable for mass production as well as small-batch and multi-variety production needs.
Superior product quality
The produced products feature excellent performance, high dimensional accuracy and superior surface finish.
Differences in Application Scenarios
Traditional extrusion processes still have a certain application scope in the processing of special products with low requirements for dimensional accuracy and performance, and small production batches. In contrast, continuous extrusion machines are mainly applied in fields with high demands for product quality and length, such as the manufacturing of outer conductors for CATV coaxial cables, sheaths and skeletons for optical fiber composite overhead ground wires, and aluminum-clad steel wires.
Conclusion
With numerous advantages, continuous extrusion machines are gradually reshaping the landscape of the metal processing industry. However, traditional extrusion processes will not be phased out immediately and still play a role in specific scenarios. Enterprises can select the appropriate extrusion process rationally based on their own production needs and product characteristics to improve production efficiency and economic benefits.
