Large copper tube billets are thick and difficult to process directly into small-diameter products such as copper tubes used in air conditioning systems, laboratories, and other precision applications. Therefore, copper tube manufacturing requires an additional stage known as combined drawing, one of the most effective methods for reducing billet dimensions.
The copper tube drawing machine plays a key role in this process, enabling manufacturers to achieve precise tube dimensions while maintaining product quality.
I. What Is Combined Drawing?
Combined drawing is the fifth stage in Ruby Copper’s copper tube manufacturing process and is carried out immediately after the planetary rolling stage. Within the production layout, the copper tube drawing machine is positioned directly after the rolling machine.
The primary objective of combined drawing is to reduce the wall thickness of the copper tube. After processing, the tube is collected into a storage basket and transferred to the final drawing stage.
II. The Synergy Between Combined Drawing and Final Drawing
It is easy to notice that the copper tube manufacturing process includes two consecutive drawing stages. These two operations work closely together to shape the final product.
Combined drawing serves as the preliminary shaping stage before the tube enters final drawing. In other words, it is the first step in tube sizing and plays a crucial role in making subsequent processes—including final drawing, coiling and cutting, bright annealing, and packaging—more stable and efficient.
The final drawing stage receives semi-finished tubes from the combined drawing process and further reduces their dimensions using multiple drawing dies according to specified output requirements.
Together, these stages ensure that copper tubes meet both manufacturer specifications and customer requirements. Throughout the process, every copper tube drawing machine is carefully monitored by skilled technicians and supported by advanced testing equipment, including tensile testing machines, spectrometers, and chemical composition analysis systems.
Any abnormalities that may affect product quality during either drawing stage are identified and resolved promptly.
III. Advanced Combined Drawing Technology at Ruby Copper
1. Combined Drawing Machine
Ruby Copper utilizes a straight-line copper tube drawing machine equipped with two drawing dies, known as the inner die and outer die. The copper tube billet is simultaneously drawn through both dies.
A force compensation system is installed between the dies to ensure smooth and continuous operation throughout the drawing process.
After the first drawing pass, the tube size is typically reduced to approximately 38 × 1.75 mm, with a drawing speed of 40–50 meters per minute. These dimensions can vary depending on the machine settings and production requirements.
The processed tube is then coiled automatically and transferred to the next drawing operation.
2. CAM-Driven Combined Drawing Carriage Technology
Simply put, Ruby Copper’s copper tube drawing machine system simulates the motion of a pulling carriage driven by a CAM shaft. The material being drawn is the coiled copper tube produced after the planetary rolling stage.
During combined drawing, the tube is continuously pulled forward while passing through the drawing dies. This process simultaneously reduces the tube’s diameter and wall thickness to a predetermined size.
The advanced copper tube drawing machine technology enables highly consistent production results while minimizing dimensional variations.
Ruby Copper’s automated combined drawing system has been optimally designed and installed to ensure fast and accurate production. Thanks to its integrated manufacturing process and highly experienced quality control engineers, each copper tube drawing machine can operate continuously for years while maintaining stable performance and reliable product quality.
As one of Vietnam’s leading copper tube manufacturers, Ruby Copper continues to invest in advanced copper tube drawing machine technology to improve efficiency, precision, and product consistency across its production lines.
