Neri works with architects from all over the world and shares with them its know-how. Neri examines the characteristics of each project and takes care of the whole process from concept to finished product. After a careful study the model is made, this is the first and indispensable step of the production cycle.This presentation shows the different production steps of a new lamp post base, specifically conceived for an important leisure park project. It is a very large base, its dimensions being dictated by the need to include in the post not only the lighting equipment,but also devices for sound diffusion, light effects and security. We will follow its production step by step through the foundry all the way through to the final painting.
The process starts in Neri design department, where the drawings of the model are made. Here designers study the shapes, the disposition on plaques and the subdivision in different parts,the latter being required in order to have an optimal cast.
In Neri model department a wooden model is realised, which will then be used in the foundry. It is a long and engaging task, whichis further complicated by the dimensions of the product. A similar model is made to produce the core, a necessaryelement to create the inner cavity. The model is finally positioned on the plaque and sent to the foundry, where the production of each single piece starts.
In the foundry, the model created by Neri is put inside a large steel bracket in which a special kind of resin-sand is poured. When it hardens, it exactly reproduces the shape of the model. The shape impressed in the resin-sand (mould) is then separated from the modelthen treated with special coatings that will improve the detachment of cast iron from the sand. The operation is carried out once again, to create the other half of the base. The coated moulds are then baked, so as to make them more resistant and solid. Now the two shapes aligned on the ground are prepared for the positioning of the ‘inner core’. All the ‘inner cores’, them too made of resin-sand, were previously prepared. Given the dimensions of the base, they weigh 750 kg each. The ‘cores’ are put with great care inside one of the baked moulds. It is a very delicate passage. The precision with which the core is positioned directly determines the quality of the casting. The two earthen moulds are then combined by superimposing the empty one to that containing the core. In this bracket, that also encloses the base shape, melted cast iron is poured, at a temperature of 1,450°C. The following day, when the cast has cooled down, an enormous mechanical arm frees it from the bracket and from the sand-resin. It is then set on a vibrating platform that completely crumbles the sand, including the internal core.The raw fusion then crosses a tunnel where it is bombarded with small steel balls in order to free it of any sand residue (sandblasting).
Once the piece has been cleared of any burrs, with its surface clean and smooth, it returns to the Neri factory to be painted. Each cast is hand filled in order to eliminate imperfections in the cast iron where removing the base has left an uneven surface. All bases are dipped in a large tank containing liquid galvanising zinc, capable of protecting the cast iron from rusting both inside and outside.Since the project requires various shades of colour on the same piece, after an initial coat in green, the parts that have to remain green get covered. All the other parts are then painted with a different shade of green. Once the pieces have dried, the masks are removed: in this way the various shades of colour are revealed, giving the piece a refined and elegant character.
The numerous phases of a long job – design, modelling, fusion, and painting – are over. The packaged bases are waiting to start their long journey to Shanghai. Many thanks go to Fonderia SCM of Rimini for their precious collaboration.