F.LLI NAVA

Presses and extreme stainless steel forming

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Nava press 2MI 1100500, drawing machine characterized by maximum ram force of 11,000 kN.
Nava press 2MI 1100500, drawing machine characterized by maximum ram force of 11,000 kN.

Design of very complex products in order to optimize costs and/or to eliminate welded couplings. This is the activity of Steel Form Group, in whose process play an essential role the performances offered by nava presses, highly performing machines characterized by outstanding technological content.

Know-how and innovation: these are the common denominators on which F.lli Nava and Steel Form Group have grounded their business growth. F.lli Nava was born in the early Sixties, from the strong motivation with which the founder brothers have pursued their intent of creating something new in the sector of hydraulic productions presses and extending, in time, their technological offer. Steel Form Group, thanks to the forty-year experience of its founder Enzo Sinigaglia, is instead reference partner in the production of complex products through forming, exclusively made of stainless steel by annealing with thicknesses ranging from 0.6 to 4 mm. Common denominators that have given rise to a collaboration relationship where precise specific requirements have found a partner able to satisfy them, turning ideas into winning solutions. «The winning idea – explains just Enzo Sinigaglia – has always been to research the way to manufacture components that generally need more phases, from assembly to welding, in a single piece. Thus offering an advantageous alternative in economic terms but anyway satisfying fully also the aesthetical aspect». Activity that in time has led Steel Form Group to obtain important outcomes in national and international ambit, in key sectors like catering, industrial washing and cooking, besides the increasingly demanding medical field. A market appreciation that it was possible to attain also thanks to the significant contribution of the process quality, which the company fully masters. «Quality and productivity – adds Sinigaglia – assured also by the presence of numerous presses specifically designed for our needs by F.lli Nava, hydraulic presses and special plants, together with post-forming equipment designed and developed upon our technical specifications, aimed at optimizing each phase of the productive cycle».

Enzo Sinigaglia, owner and founder of Steel Form Group.
Enzo Sinigaglia, owner and founder of Steel Form Group.

Deep, even very deep, drawing
Thanks to the deep experience gained, F.lli Nava in fact confirms to be a reference supplier for applications with high content of quality and performances. An ideal technical partner for all die makers believing that technology is a precious trump card to keep their competitiveness level high. In this context manifold are the application fields of presses and of the manufactured equipment, in detail the cold forming of sheet metals, the moulding of thermoplastic materials for applications in the automotive industry, hydroforming of sheet metals and tubes, versatile die spotting presses both for the production of small pre-series and for the fit testing of the two parts of the tool itself and related adjustment, complete press lines, tube and semi-finished product (both precision and steel structural works) straightening machines. Inside the factories at Vignate (Mi) of Steel Form Group are currently operating 7 presses supplied by F.lli Nava, with a pressing force from 250 to 1,100 tons. Among them stands out 2MI 1100/500, drawing machine characterized by maximum force of the ram of 11,000 kN, lower blank holder 5,000 kN, third upper action 800 kN, 2,500 x 1,800 mm worktables. With lower active and passive blank holder, extended regulation range of the blank holder to reach even very low forces with good repeatability, that machine was born as solution to specific deep and very deep drawing requirements for stainless steel tanks. This machine – feature anyway peculiar for all Nava presses – is characterized by a very linear and intuitive man/machine management interface, thus coupling the availability of sophisticated regulation functions with the very simple and intuitive use, making available for users all working and diagnostics functions in very pleasant and accessible way. Technique and technology addressing then a high-end market segment, where the press quality can necessarily make the difference, permitting to produce pieces otherwise unconceivable. The collaboration and the strict co-design between customer and supplier have therefore permitted to accomplish the highest evolution in the die technology, intercepting the increasingly advanced requirements and the targets of higher competitiveness. «This resulted in a machine – adds Sinigaglia – prearranged with a fully manageable third action, also equipped with very high force in comparison with what necessary for the only piece drawing. This in fact permits to realize pre-drawings to recall the material to be spent in successive process phases». Still according to this vision, Nava has conceived a lower blank holder able to work both in passive way (in standard way, that’s to say operating the drawing ring that contrasts the sheet metal flow in the die), and in active way (operating the drawing tool). The latter possibility allows a great enlargement of the range of components that can be drawn with equal nominal press force, because it allows using a resistance on the sheet metal corresponding to the maximum force of the ram (then doubling the previous limit given by the nominal force value of the blank holder), with anyway remarkable active forming force. Among the elements that characterize the presses manufactured by Nava, besides performances and very flexible regulation capacity, the operator safety and the operation reliability play a central role. Thanks to the safety implemented and monitored at several levels, often extending the requisites provided for by regulations, it is assured a working environment quality that allows operators to fulfil the entrusted tasks in optimal way, with utmost tranquillity and therefore with certainly relevant motivational effects. On the other hand, the reliability in the machinery use allows uninterrupted production, free from micro and macro downtimes, concretely creating the preliminary conditions to be able to respect very short lead-times, certainly then a cut above in a more and more demanding market also from this point of view.

Technicians of F.lli Nava standing in front of the new 600-ton press in installation phase at the Steel Form Group factory of Vignate (MI).
Technicians of F.lli Nava standing in front of the new 600-ton press in installation phase at the Steel Form Group factory of Vignate (MI).

From bottom to top
It features instead 600 tons the new press recently installed by Nava still in the factory of Steel Form Group. «An acquisition  – underlines Sinigaglia – essentially dictated by the present needs of work progress management for determinate job orders. Ii is actually under study, together with Nava technicians, a new machine with much higher power than the one presently installed, plant that will allow us to open a new market». A market that will not be distant from those currently conquered and core business of the company (catering, industrial washing and cooking, medical) but proposing a valid alternative of product obtained through an optimized process with a single forming cycle (economically advantageous) and even higher final quality (also aesthetical). «The logic that we follow – adds Sinigaglia – is the same: analysis of the stainless steel product/article bent and welded and successive study that permits its attainment in a single forming cycle, with all inherent advantages: at the end of the described optimization process, the piece is submitted to the final customer, accompanied by the reliability gained by our company over the years». In the same identical way with which in the Nineties the owner proposed a renowned German manufacturer the implementation “in a single forming”, of a capote dishwasher tank until that time manufactured with bent sheet metal and afterwards welded. Solution that has solved criticalities due to the aggressiveness of detergents and water, not altering anymore in time the initial integrity conditions of the article. «A really complex piece to be produced – ends Sinigaglia – one of the most difficult to be manufactured with a single forming, but in 15 years produced by us in more than 100,000 units». And it is still in the industrial washing ambit that Steel Form Group is getting ready to win new challenges with new projects scheduled for the next future. Evolution once more based on the winning partnership established with Nava or the development not only of customized forming plants but also of automated equipment and systems aimed at making the forming process more and more flexible and performing, downstream the main forming. As guarantee of the best possible competitiveness, the full compliance with the certification obtained not only for the ISO 9001 regulation but also for the ISO 14001 one, as well as the ISO 9001 regulation compliance of the supplier F.lli NAVA srl, a further confirmation of the consolidated renown on the market.

The machine fleet of Steel Form Group includes also two annealing furnaces.
The machine fleet of Steel Form Group includes also two annealing furnaces.

The company at a glance
Headquartered at Vignate (MI) the activity of Steel Form Group is based on two complementary production units employing a staff of about 35 people and one dozen of collaborators, for a yearly turnover that in 2013 reached 11 million Euros. A fruitful collaboration suitable for supporting customers in the design of very complex products, in order to optimize costs and/or to eliminate welded couplings. This makes Steel Form Group a company always in the forefront and researching innovative forming solutions. Activity carried out in flexible and streamlined manner, made possible by the total and complete control of the whole productive cycle. Inside the factory there are in fact all the machines to execute the complete product cycle, starting from sheet metal and up to the final polishing. Concerning polishing, the company is specialized in vibro-shot-peening with stainless steel balls (tumbling), a process that is applied in catering to make the surfaces less attackable by corrosive agents. Besides the presses supplied by F.lli Nava (with pressing force from 250 to 1,100 tons), the machine fleet includes also two annealing furnaces, two tunnels for the piece washing, 3D laser, welding robots and a department equipped for finishing.