IOIS Gioielli experiments with new technologies at the Digital Innovation Hub of Rome

In addition to being one of the excellences of Roman goldsmithing, Fabio Felici, owner of the IOIS Gioielli brand, is also one of the most loyal customers of our Digital Innovation Hub.

The encounter with Fabio and his wonderful creations took place in 2018, thanks to the CNA Roma network, at Spazio Chirale alla Garbatella.

IOIS Gioielli stands out for its contemporary design, never trivial yet sophisticated and elegant.

The geometries of his collections are unmistakable.

In recent days, we had the pleasure of hosting IOIS Gioielli again at our Ostiense workshop to present the latest technologies just installed and to assess the possibility of fine-tuning a process for the production of one of his new creations.

This is a service that is part of our offering to artisan and manufacturing companies and currently engages a significant percentage of our facility.

Without being able to anticipate anything about that latest project, in this article we want to tell you about the first interesting collaboration episode between us and IOIS Gioielli, which led to the fine-tuning of a digital fabrication process unusual in goldsmithing applications.

How is digital fabrication applied in the goldsmith’s art, and what is the element of originality fine-tuned through this project? We are about to tell you.

At the time, Fabio Felici, like many of his colleagues, was considering the move to digital technology for the production of his jewellery.

The goldsmith sector, in fact, is one of those fields in which 3D printing has replaced the traditional process providing immediate, easily measurable advantages.

The traditional technique for making precious-metal objects is the so-called “lost wax”. According to this process, the craftsman models his creation using wax. Modelling can be done by sculpting a wax block, but also by assembling small pre-modelled wax objects — such as small flowers, leaves, little rings, etc.

Once the jewel has been modelled in wax, a clay or plaster mould is made, containing the wax object inside and equipped with “feeding channels”. The channels are made by attaching wax cylinders directly to the sculpted object; the mould is built by placing the object — with the cylinders attached, which will create the channels — inside a container and pouring liquid plaster or clay into it.

Once the plaster or clay has solidified, the mould is placed in the casting furnace and the molten precious metal is introduced under pressure through the channels.

The wax melts and flows out through the channels prepared for its drainage, and the hollow part of the mould is filled by the molten metal that takes the wax’s place.

Everything is allowed to cool and then the mould is broken to extract the cast metal object. Where the channels were placed there will be small precious-metal cylinders, which the craftsman removes with shears.

The object will look very rough. Through tumbling and polishing operations, the jewel will take its final form thanks to the skilled finishing work carried out by the craftsman with their tools.

The use of 3D printing makes it possible to evolve this process by replacing the steps of modelling and sculpting the wax object with the digital fabrication of the object in plastic material.

Instead of sculpting the object in wax, the craftsman models his creation using CAD software. Once the 3D model of the creation is built, the digital file is sent to a 3D printer and then fabricated.

The 3D printing technology usually used in this sector is stereolithography. The fabrication material is therefore a photopolymer — a material made of repeating-chain molecules called polymers, synthesised from a fluid resin through the input of light radiation, generally in the ultraviolet range. This kind of material falls into the category we colloquially call “plastics”.

For jewellery applications, photopolymers are used that have characteristics very similar to wax, so the 3D-printed object can be used in the process in place of the wax object. The feeding channels can be made directly in the 3D model and printed as part of the object, or they can be added in wax by the craftsman before pouring the mould.

What is the advantage of 3D printing over the manual process using wax?

The answer is that there are several advantages that make the process much more effective and able to make the craftsman more competitive.

Let’s see them in order.

First, modelling is digital. Although the image of the sculptor-craftsman seems more associated with art, 3D modelling done with CAD software is an equally difficult and artisanal process, but capable of generating shapes and geometries impossible to achieve with manual modelling and sculpting techniques. Think of complex, organic-style or voronoi geometries.

Moreover, most young designers come from Art Academies, where the use of digital tools is now taught.

The new digital-modelling software massively expands creative possibilities. A designer who masters these tools can produce shapes and geometries that are unimaginable to a traditional sculptor.

The second advantage is that 3D printing can produce the object with extreme precision and high resolution.

Once the polymer has been melted and replaced by the precious metal, the rough object will look much more refined than what can be obtained from the wax model — especially in parts less accessible to working tools — with the result that the subsequent finishing process will be shorter and, above all, will generate less material waste.

The third advantage is that 3D printing can fabricate shapes and geometries with any degree of fineness and complexity. Many 3D-printed objects simply could not be made otherwise.

The evolution of the goldsmith sector in recent years shows that 3D printing has provided undisputed advantages to the craftsmen who adopted it.

Goldsmith companies can experiment in our labs with 3D modelling and printing technologies and verify their applicability and benefits in relation to their own production processes, before making the investments needed to acquire machines and skills to digitally re-engineer their production.

But Fabio Felici had not contacted us for this. Already fully convinced of the advantages of the digital process, his need went beyond simple experimentation and adoption of the solution already in use by many of his competitors.

The problem raised by IOIS Gioielli concerned some well-known disadvantages of the technology usually used in his sector — that is, photopolymer stereolithography.

The first disadvantage is the high cost of the printers that use this technology.

The second disadvantage is the need to ensure the proper storage of the resins used as raw material, the short lifespan of many printer accessories — particularly the resin trays — and the need to apply continuous cleaning and maintenance procedures to the machine and its accessories.

The third — and most important — disadvantage in the case of IOIS Gioielli was the need to use chemical products — resins and cleaning solvents that are volatile and toxic — inside a small workshop open to the public.

To overcome all this, Fabio Felici’s idea was to use FDM 3D printing technology — the more widespread filament-deposition printing used by millions of hobbyists worldwide.

FDM 3D printing is universally adopted in industry because it is the only technology that allows printing with any thermoplastic polymer, while stereolithographic printing is limited to photopolymers, which are low-performance materials not usable in applications where strength and wear characteristics matter.

Stereolithographic printing is in fact used exclusively for prototyping design objects, in goldsmithing and dentistry. In these three fields it is the technology of choice thanks to the higher resolution of the fabricated parts, since the quality of finish is more important than mechanical characteristics.

In the case of IOIS Gioielli’s artistic production, shapes, geometries and dimensions play on volume effects and movements that do not require high resolution in object fabrication. The products are easy to finish through tumbling and the craftsman’s bench work, and present no critical elements.

After looking at his creations, we agreed with Fabio that resin STL printing would in fact be unjustified in light of the disadvantages listed above.

We therefore launched an experimentation project to verify the feasibility of the process via FDM 3D printing.

The main problem we identified concerned the characteristics of the material to be used.

Silver has a melting temperature of about 962 °C, gold of about 1,064 °C. At those temperatures, almost all polymers workable with an FDM 3D printer are already well past their melting point. The problem is therefore not the possibility of melting the material in place of the wax or photopolymer used in STL technology.

The problem stems from the viscosity characteristics of the material in the liquid state and the degradation processes that occur at high temperatures.

The “resins” specifically developed for goldsmithing have been designed by manufacturers to be “burnable” — that is, subject to a process whereby, at high temperature, most of the compounds making up the impurities of the material are removed by evaporation or sublimation so that, after melting, no ash residues remain that could dirty or contaminate the jewel.

The wax used in the traditional process is a burnable material.

When STL technology was developed, burnable photopolymers were also fine-tuned.

In the field of FDM printing, the same attention has not been there.

Bringing a normal 3D-printing filament above 500 °C results in the crystallisation of part of the material and the production of abundant carbonaceous residues and ash — exactly what is not acceptable in the lost-wax casting technique.

In reality, some manufacturers, mainly in the US, produce wax-based composite filaments declared as burnable. Unfortunately, in our case — between the small number of manufacturers, importation and the base cost of the material — choosing such products did not look convenient.

We therefore launched a research process, leveraging the advantages offered by our open innovation model.

Research on FDM printing usually focuses on the mechanical and physical characteristics of the final products and on the optimisation of the production process.

In particular, in this last area, research has always focused on guaranteeing the ease and repeatability of printing processes. In this case, the efforts made by 3D-printing filament manufacturers have been considerable and aimed at producing composite materials that limit the phenomenon of “shrinkage” and detachment from the print bed during fabrication.

The choice of suitable colour pigments and the mixing with fluidifiers have made it possible to produce filaments that are very easy to print. Among the problems solved by these materials is also the low residue production, so as not to clog the printers’ extruders.

Moreover, in our research conducted at the dawn of 3D printing applied to jewellery, we had the privilege of working with and getting to know some of the best casters active in our region — highly skilled craftsmen who are a real mine of information about the physical-chemical process taking place inside the mould during the substitution of wax or resin with the molten precious metal.

By combining the knowledge built up in 3D-printing-filament experimentation with the knowledge on the casting process and the analysis of the geometries of IOIS Gioielli’s creations, we quickly arrived at a solution.

Fabio Felici today is able to produce his jewellery using a fairly inexpensive PLA filament — experimentation has in fact identified a specific commercial brand, widely available on the market, and a specific product and colour from its range, that guarantees the highest production quality at the casting stage.

The case history just told is an example that clearly illustrates the support service we offer to the research activities of artisan companies.

IOIS Gioielli is one of the many companies that turn to our Hub whenever the market offers them the opportunity to develop an innovative product.

The results obtained through these projects become a heritage of knowledge shared with all the actors connected to the Digital Innovation Hub.