Introduction
It is interesting to know that roll forming is an important and widely used process in metal forming, with over 40% of the steel used in various industries, including construction, automotive, and machinery, being produced using this technology. Due to its importance, in this section of the Persian Sazhe blog, the largest database of information on buildings and structures under construction in the country, we will discuss this process and provide you with complete details about this field, so stay tuned.
What is Roll Forming?
Interestingly, roll forming is a widely used yet relatively unknown process. In fact, it can be said that describing and explaining the roll forming process is not an easy task, but in general, it can be said that the process of shaping metal sheets in a straight, longitudinal, and parallel line with bend lines using multiple sets of contoured rolls without changing the thickness at room temperature is called roll forming.
About the Roll Forming Process and Its Details
In general, it can be said that roll forming is always referred to as an important and widely used process, as it has grown over the past half century as the most efficient metal forming technology. In fact, it is interesting to know that about 35 to 45 percent of all steel produced by US mills is produced by the roll forming process, which is a higher amount of steel used in the automotive industry. Considering this issue, it can be said that hundreds of vehicles, cars, buildings, agricultural machinery, tanks and other products are produced daily by the roll forming process, but most people outside of this profession do not even have the slightest familiarity with this industry.
Roll Forming Process for Sheets
In order to obtain a functional and applicable product, different methods have always been used in any process to achieve the output. In this line, roll forming methods for sheets exist in various forms, and according to this issue, roll forming methods can be classified into the following:
- Cold Roll Forming Method
In a general overview, it can be said that sheets that are produced with a minimum thickness by hot rolling are usually subjected to a process of decreasing thickness or changing shape through the cold rolling process after acid washing. In fact, it can be said that the application of cold rolling is to reduce the thickness with the desired dimensional accuracy of steel sheets. In addition, in this cold roll forming process, it can be mentioned that the sheets are also flattened during the operation, in such a way that the roller, which includes two sets of rollers with a small diameter, eliminates the curvature of the sheet created in the previous process and becomes flat as it exits the roller. In fact, the purpose of cold roll forming is to reduce the thickness of the sheet under very high pressure, which is usually done at room temperature and up to 200 degrees Celsius. In this cold method, factors such as the characteristics of the sheet roll forming machine, the skill of the tool designer, the quality and performance of the designed tool, the skill of the operator, the method of tool installation, and the formability of the sheet strip affect the success of the process. The application of this process in sheet metal working industries is very diverse, covering a range of parts from low-precision to sensitive and precise parts.
- Hot Roll Forming Method
The hot method is used to form thick sheets. In general, in this method, the temperature of the metal sheets is raised to a very high level to help form the thick sheets. Hot rolling is less popular than cold rolling and products produced by this method have limited applications. Products such as beams, angles, or thick formed sheets such as plates are roll formed using the hot roll forming method. Performing the roll forming operation of the sheet using the hot rolling method requires great care in adjusting the desired temperature, as changes in temperature, increase or decrease in heat may lead to the destruction of the products. This is why only a few factories use the hot rolling method.
Forming Process of Galvanized Sheets
As you know, galvanized sheets, which have a zinc coating on their surface, are produced in various colors. On the other hand, the painting of galvanized sheets is done using a spray or by placing them in special ovens. Galvanized sheets with a thickness of 6 to 18 mm are formed in various designs using forming machines. In this line, one of the traditional methods in shaping this product is the sinusoidal pattern. The sinusoidal pattern has a shape similar to sea waves, which is often used in the construction of gable roofs or false ceilings using galvanized sheets with this pattern. It is also worth mentioning that another method in forming galvanized sheets is the trapezoidal pattern. In general, this design is more suitable for high-traffic areas with humid air. Of course, this method itself has three different types.
