In the traditional sense, a tube Mills is a type of welded rolling form machine; but not every welded rolling form machine is really a tube Mills. Actually, tube mills are special welded single-piece roll forming machines that are fine-tuned for running a certain size range, usually at high speeds (Figures 1 and 2). A typical tube mold machine consists of a large drum, and a series of rollers or rolls (usually Teflon coated steel) which are placed inside the drum, and which move in a pattern, as illustrated in Figure 3. Because the rolls on the drum can be manipulated at high speeds, they can be made to rotate rapidly, which creates a quench. Because of this quench effect, the product created by the milling process is typically stiff, and of good quality.
The purpose of these tubes is not purely for manufacturing goods, but rather as a method for pre-punching metal, to form the basic components of most heavy-duty products. Typically, pre-punching metal requires a very high degree of precision, and because the metal must be perfectly punched, it often eliminates the need for cutting (otherwise known as “cutting-edge fabrication”). Also, as the metal is pre-punched, it leaves no imprint or design marks, which further ensures accuracy. Tube mills have become especially popular for pre-punching because in comparison to standard machining methods, it is much faster.
Tube Milling is typically used in a variety of applications where precision and speed are paramount, as illustrated by the fact that it forms the basis of the industrial tooling system used by many automobile manufacturers. It is widely accepted that many traditional metals can only be fabricated into shapes at a low rate; this is particularly true for metals with extreme deformation, like aluminum, steel, titanium and iron. But with welded roller rack machine (RWMs) and tube mills, manufacturers can easily fabricate intricate shapes, as illustrated by their use in a wide variety of applications, from automotive seats to marine applications. In addition, due to the speed at which these machines work, some manufacturers are able to produce detailed curved shapes and hollows at extremely high speeds.
The main advantages of using welded roller form systems are their high efficiency, easy application and simple maintenance. Also, they require very little wiring, no need for a shielding, they do not require lubrication and they do not display any sign of wear. This allows for a quick change-over and saves time and money on repair bills.
Another important advantage of tube mills is their ability to use both direct and alternating current (DC) and convert the electrical energy into mechanical energy for useful work. They have the ability to work in extreme temperature ranges and can be run with a small or large voltage. Another important feature of these machines is that they have an idle stop, enabling them to work with high load and voltage conditions. In addition, they have the ability to use both pulse and continuous flow techniques and have the ability to fine tune the pulse width. And, due to their compact size, they have the ability to use a variety of joining processes.
In essence, the basic difference between DC and RF tube mills lies in their use of induction heating for completing the arc forms. With the induction process, the operator initiates the arc charge, much like a conventional hand piece would. Then, by using a finely tuned to consummate, the operators switch to a lower power setting, and the formed objects are deposited quickly. The RF versions, on the other hand, utilize high frequency electromagnetic pulses to work in much the same way, only with the RF pulses operating at a much higher frequency.