Out of various fabricating methods used for shaping metals, roll forming is perhaps the most efficient and productive process. It not only allows faster formation of metal rolls of varying sizes, material thicknesses, and lengths, but it also saves a lot of costs by reducing energy consumption and human intervention. While there are several roll forming methodologies utilized in the manufacturing process, it is the tube roll forming process that has proven to be more promising and high-yielding.
When coupled with different operations, including welding rolls, roll forming mills, and precision-forming rolls, this metal fabrication process allows professionals to manufacture a myriad of end products. What’s more is that the method brings in more efficiency and precision in the entire metal processing cycle, thereby contributing to the overall deliverables and productivity. Having said that, this following article will further focus on some of the major aspects of tube roll forming, including its process, benefits, and so on.
What is tube roll forming and how is it better than tube bending?
Tube roll forming is a special metal forming process by which closed tubular sections of varying radii and consistent material thickness can be produced in less time. In this process, a metal sheet is passed through a set of forming rolls in a roll forming mill. The rolls apply a certain amount of pressure to create minimal bends in the metal sheet. Due to this, only smaller bends are created at a time, and that too at a gradual pace until the final product is obtained as per the design.
As the pressure applied on the metal sheet for forming the bends is quite low, achieving smaller radii in the tubular structure is possible with tube roll forming. Furthermore, it ensures consistent material thickness throughout, with no stretching or compression at the bends. It also reduces the spring-back action of the end product due to the gradual bending process of the sheet metal when passed through the forming rolls. That’s why the process is preferred over the conventional tube bending process in several manufacturing operations.
Why is welding necessary in tube roll forming?
The tube roll produced at the end of the forming roll mill has open endings, which need to be joined permanently to form the closed enclosure. This is where welding enters the picture. Several welding techniques are usually implemented to join the ends of the flat metal sheet together so that the tubular structure can be obtained as per the initial design requirements.
One such method is the HFI or High-Frequency Induction welding in which electromagnetic waves are used to produce high quality of heat needed to fuse the open ends of the tube rolls. Another method used is the laser welding where laser beam is used to generate the fusion heat and weld the metal ends properly and with sheer precision.
The choice of the welding technique usually varies on numerous interim factors that should be considered appropriately. For instance:
- Production volume: If the desired production volume for the concerned manufacturing project is high, professionals should rely on a welding technique that can fuse the metal ends of the tube rolls at lighting speed while ensuring optimal accuracy and precision in the joins.
- Weld quality: In several operations, the weld quality required for tube roll forming is quite high. Based on that, the welding technique will vary. For instance, hydrocarbon welding cannot create high-quality welds as compared to laser or high-frequency induction welding techniques.
- Material properties: Not all materials used in forming the tube rolls are compatible with laser welding or hydrocarbon welding. Therefore, while choosing the appropriate welding technique, considering the material’s physical, chemical, and mechanical properties is imperative. Failure to do so might result in material damage and improper welding.
What tools are needed for tube roll forming?
It is imperative to choose the right tooling material to achieve enhanced efficiency and high precision in the tube roll forming process. For instance, aluminum bronze rolling mills are often preferred because the tool has excellent sliding ability, lower elongation rate, and enhanced hardness. Therefore, when the material is passed through it, the shaping and movement are controlled accurately and the bends formed are uniform throughout.
Following are some of the factors that need to be considered while choosing the tooling materials for tube roll forming method.
- Mechanical properties: Based on the mechanical properties, the choice of the tooling material will vary. For instance, if the tensile strength of the concerned material is quite high, choosing a tooling material that can compensate for the high tensile strength and counterbalance the material’s resistivity is more feasible.
- Sliding properties: If the chosen tooling material for tube roll forming doesn’t have enhanced sliding properties, it will cause more friction between the forming rolls and the material as the latter passes through the rolling mill. This will not only damage the material’s surface but also cause bumps and wrinkles along its length, thereby leading to material damage and improper design of the end product. Therefore, choosing a tooling material with improved sliding properties is crucial.
- Hardness: Another important factor to be considered while choosing the tooling material for tube roll forming is the harness of the forming rolls. If this parameter is not high, the wear and tear will be colossal, which will ultimately damage the forming rolls and render the rolling mill useless after some time. Furthermore, weaker forming rolls won’t be able to generate the required amount of pressure needed to create bends in metal sheets with greater material thickness.
What are the applications of the tube roll-forming technique?
The tube roll forming technique is used to achieve greater efficiency and higher precision in forming enclosed tubular structures of varying radii and material thickness. Unlike the conventional tube bending process, roll forming won’t cause spring-back of the material after being passed through the rolling mill or create non-uniform bends. That’s why it is preferred in several industrial applications, including automotive, construction, aviation, energy, and so on.
Conclusion
In this article, we have discussed the major aspects to know about tube roll forming, including its superiority over tube bending, the involvement of the welding process, and so on. Based on the discussion, you now understand the benefits you can unlock with this technique in the manufacturing process.