A bent for calendering and bending, better and better and of bigger sizes


Backed by the competences gained in the calendering and bending of structural metal profiles, a company in verona area widens its machine fleet with a new MG profile bending machine. an acquisition that allows satisfying even better the more and more challenging requirements of the mechanics, structural engineering and building sectors.

(From the left) The founder of Tromba Maurizio di Verona, Marcello Tromba, together with his sons Maurizio, Nicola and Andrea.

In the ambit of the subcontracting sheet metal working, it is not infrequent to meet companies that along the years diversify their activity, widen the services and the machining typologies offered. Others, like Tromba Maurizio S.n.c., make specialization a boast and a precise growth strategy. The company, established in 1967, started manufacturing calendered flanges and bending small-size profiles; then, it gradually acquired the equipment to work geometrically bigger and bigger components, due to the purchase of increasingly performing machines. A change of pace started in 1996, when the owner and founder Marcello Tromba was joined by his sons Maurizio, Andrea and Nicola. «An entry – explains Andrea Tromba – that involved the introduction of profile bending machines to work bigger sizes. Precisely in these years we have known MG, the manufacturer of plate and profile bending machines and the machines it could design and produce for our sector». A meeting that has turned into a real technological partnership, concretized in time with the purchase of a bender and as many as 5 profile bending machines. Among them, also AR 530, a giant with 3 shafts with 540 mm of diameter, with a total thrust power of 1,900 tons per 50,000 kgm of available torque in rotation.

Some tubes with 609 x 25 mm diameter, with 3D bending for Roller Coasters.

Keeping pace with the innovation of materials

«We have been customers of MG – underlines Tromba – for almost twenty years now and we turned to this manufacturer as we assessed its reliability, competences and especially great willingness to welcoming our requests. Our constant challenge to stand out on the market has been in fact always oriented to the search for more powerful machines». The bending sector, in fact, is not static and standard at all, concerning both the profile and the machining. Without neglecting the constant improvement of the intrinsic characteristics of the machined materials. An evolution that the company must consider attentively to keep pace, constantly upgrading its machines and plants. «Carrying out on a current material – adds Tromba – the same machining executed just a dozen of years ago does not give the same results». The company can machine materials like brass, copper, aluminium, iron (soft and hard), steels, including high-strength ones, availing itself of a broad machine fleet. In 2001, they bought from MG the first AR 110 profile bender (replaced some months ago with a new upgraded version), followed by an AR 360 in 2005 and by a plate bender in 2007. «As completion of the workable geometries – specifies Tromba in person– we added then in the workshop also the AR 60, AR 180 profile bending machines, the renowned AR 530 and, last acquisition, a new AR 200, delivered within May of the current year».

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Evo 4.0 self-calculates the reaction of the material under calendering and generates programmes for bending any shape.

Evo 4.0 is the last version of the CNC system fully integrated with MG machines, including also the new AR 200 recently installed at Tromba Maurizio. Designed thanks to years of direct experience and knowledge, the new control maintains a user-friendly interface, due to the use of a powerful digital motor that offers a control precision never found before on a bending machine. The closed loop system constantly controls the positions of rotation and of lateral rollers. With Evo 4.0, the computer self-calculates how the material reacts under calendering, to be able to generate programmes of any form automatically, with the material input in library for: circles, quadrangles, triangles and ellipses. Due to its concept and implementation, such control is perfect for the volume-manufacturing of cylinders and bulb screw bases or for the execution of complex shapes that are not easily reproducible using the manual controls of the machine or with a simple PLC sequencer. According to what required by Industry 4.0, the control can be fully integrated into the corporate net. It makes available all the data concerning the machine state and the production of the various machining processes. Besides, it adds the predictive diagnostics, suitable for improving the production efficiency, managing the maintenance planning autonomously.[/su_box]

Reliability and performances

Available in 14 standard models and configurable with three or four rollers with double pre-curved, MG profile benders stand out for some technological peculiarities that make them reliable, innovative and performing machines, from all points of view. Starting, from instance, from the planetary motion system of bending rollers, aimed at drastically reducing the common frictions in machinery with traditional motions, such as hydraulic guides, or horizontal sliding ones. The two forming rollers are driven by two external pistons. This device avoids flexures and assures a perfect work finish and shorter straight edges. Worth highlighting also the “direct drive” evolution, i.e. the replacement of all low- efficiency components (gears, bushes, mechanical reduction gears, transmission belts, sliding guides and so on). All three rollers are directly powered and directly coupled with the more efficient epicyclical reduction gears, bearings and hydraulic motors. In that way, the entire force of the machine is concentrated on the profile to be calendered (positive force), thus saving energy. Distinguishing are also: the permanent lubrication (all components are pre-lubricated and sealed according to an exclusive system that grants the lubrication for the entire life); the rollers mounted on high-load bearings and with double row of rollers; the hydraulic guides with three-dimensional motion (with ascent/descent, forwards/backwards motions, the rollers rotate to suit the different bending radii). On these machines, they have provided for standard universal rollers modulated to suit all kinds of profiles; for tubes and HE, Inp, Unp profiles, are instead available special equipment that can be added to the machine. «The new AR 200 profile bending machine – specifies Tromba – is implemented in a special version, with the disjointed fulcrum of the two lateral thrust rollers. Therefore, it features a different width and higher force range than the one that would be provided by a standard version».

[su_box title=”The company in short “]Tromba Maurizio started its activity in 1967 as manufacturer of calendered flanges. In time, and precisely since 1996, due to the consistent demands for the calendering of profiles, it has specialized in bending the various sections, buying machines with innovative technological performances. From that time onwards, the technical commitment to solve customers’ countless requests has constantly grown, solving and overcoming all kinds of requirements. Now the company avails itself of nine profile bending machines that allow bending all typologies of beam sections, UNP, IPE, angles, square and round tubes with the required bending radius. The only “limit” is given by the minimum bending radius provided for by the design and safety regulations in force. Therefore, today the staff, composed by one dozen of skilled technicians, can bend profiles, like tubes up to 36 inches with thickness of 40 mm and Hem 1000 beams with lengths from 12 to 20 m and several other commercial profiles (bending exclusively executed by rollers granting the homogeneity and the precision of the required radius), with the support of lifting plants that allow handling elements weighing 10 tons maximum. The versatility of the NC plants, almost entirely purchased from MG, permits to supply a high-quality product conforming to most exacting standards required by the market. Numerous are the supplied sectors, including the oil&gas, besides the implementation of products for the structural engineering field. Besides, the company is specialized in the 3D bending of tubes for carousels and Roller Coasters and, anyway, all that needs a bending of absolute quality, ISO 9001 certified.[/su_box]

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Craft skills and technological innovation in synergy

The machine fleet on which Tromba Maurizio S.n.c. relies today allows satisfying the almost totality of the market requirements. With the possibility of processing tubes from 20 to 1,000 mm of diameter, up to thicknesses of 50 mm. Calendering is instead possible up to plate sizes of 3,000 x 15 mm. «A broad range of activity – states Tromba – undoubtedly facilitated by the versatility and by the flexibility of MG machines. Plants that fully satisfy our requirements, taking into account the high variability of our daily work, where 2-3 tool changes are almost the standard. Succeeding in performing a typical change in few dozens of minutes represents a great operational advantage for us». Technicians highly appreciate also the CNC peculiarities and the motion precision. «A synergy – underlines Tromba – that allows the highest freedom and the total compliance even in small displacements, with precision and force. In this way, I can create a tailored programme for what I am doing. With the added-value of the self-teaching». If in fact, for this machining typology, it is more common to draw up the development programmes in the technical office and afterwards to transfer them on machine board, for Tromba brothers the craft skills and the acquired competences lead to an inverse process. A sensitivity that results in the ability of executing bends often at the limits of the ordinary feasibility. «Strategies for the future? Undoubtedly– ends Andrea Tromba – satisfying the market requirements even better. Not only increasing our productive capacity but also proposing us as a partner to supply not only a bent, calendered and cut to size product but also welded and assembled in its parts. A more complete product. Concerning bending, the possibility of relying on a partner like MG, ready to accept new market challenges, facilitates our vision of the future. A concrete and glaring example of that was the development of the AR530 profile bending machine. However, as striking will be the new technological opportunities that we will develop jointly, like in the case of the new AR 200 profile bending machine.