JTF ВЕБ САЙТ (назад в Legor Group)

Цифровые документы

предыдущие издания

Jewelry and direct 3D printing: the start of a new era?

Valentina Allodi Progold S.p.A.

As part of the fourth industrial revolution, direct printing of precious metal jewellery deserves constant analysis of the current state of the art to understand whether and when a jeweller should favour this technique over classic lost wax casting methods. In recent years, our research programme has included studying printing strategies, support techniques and a general analysis of the chemical and physical characteristics of the precious powders used. With this study, we are looking at technological evolution with a more practical and operational eye, sharing our experiences and giving an honest analysis of both the good and bad aspects of 3D jewellery printing, trying to define when and why it is convenient to print jewellery items.

How can digital technologies and craftsmanship provide solutions for the heritage sector?

Ann-Marie Carey Birmingham City University

Museums have a delicate balancing act. As public institutions they have a responsibility to preserve and protect our cultural heritage, while simultaneously, providing access to their collections for scholars and members of the public.  This paper will consider the opportunities a blended approach of technologies (traditional and new -laser scanning, CAD, 3D printing and craftsmanship) can provide to bridge these conflicting demands. 

Jewellery – Is it fit for purpose? An analysis based on examination of customer complaints


In the UK, if a customer has a complaint about the quality or performance of their jewellery, the retailer can send it off, often via his Association, The National Association of Jewellers, for an independent examination by a technical expert at the Worshipful Company of Goldsmiths (who also run the London Assay Office). The expert examines the item of jewellery and makes an assessment of the problem (damage and defects) and its probable cause. He also indicates where he considers the blame lies – the customer, retailer or manufacturer. This helps to resolve the dispute.

Dos and don’ts of online retail: personal data protection vs profiling

Silvia Dalle Nogare Studio Legale Associato

Online retail is constantly increasing, tracking technologies have evolved considerably (e.g. mobile device tracking, augmented reality, social networks, data mining, cloud computing) and personal data of the Internet users are extensively used to provide customized products and services or as currency in exchange for services. A better access for consumers and business to online goods is one of the pillars on the digital single market strategy of the EU Commission: behavioural tracking is often perceived as a threat to privacy, but it may also be a potential competition issue with reference to exchange of competitively sensitive information. The speech will comment the legal framework concerning online behavioural tracking, and in particular Regulation 679/2016/UE (GDPR), Decree 196/2003 (“Codice Privacy”), e-Privacy Directive (and the related amendment proposal published on January 2017) and the decision of the Italian Data Protection Authority held on May 8th 2014 (“cookie law”) in order to share with the participants a set of guidelines for legitimate profiling.

Electro Sinter Forging: a Superhero of Powder Metallurgy

Ilaria Forno Politecnico di Torino – Alessandria Campus - Alessandria, Italia

The production of jewellery and components traditionally relies on a wide range of production methods that goes from typical artisan techniques to the sophisticated procedures used in industrial manufacturing. In recent years, powder metallurgy (PM) techniques have been increasingly adopted, even alongside traditional metal-processing methods. In particular, and in the broad sense, the jewellery sector has turned to PM techniques to alleviate design and dimensional control problems that can arise, for example, with traditional casting methods. In this perspective, Metal Injection Moulding technologies and metallic Additive Manufacturing techniques (Selective Laser Sintering, Selective Laser Melting, 3D printing) have been attracting a great deal of interest. Powder Metallurgy is still an extremely vast field of study that is leading to progess, not only in terms of design, but also in terms of optimizing material and energy consumption - its traditional function - and, above all, in metallurgic terms. Considering these factors, the technques classified under the acronym FAST (field-assisted sintering techniques), i.e. those field-assisted sintering techniques that lead to a rapid powder consolidation process, as the acronym suggests, are extremely interesting. This work outlines a specific FAST, Electro-Sinter-Forging (ESF) technique which shows, through practical examples, the advantages that can be obtained in terms of process speed and component precision from advanced mechanical properties, thanks to the possibility of obtaining micro-structural and compositional conditions that cannot be obtained by applying traditional techniques.

A Study of the Effects of Digitally Produced Casting Models on Casting Quality

Teresa Frye Owner of TechForm Advanced Casting Technology Portland, OR USA

Today’s jewelry manufacturers are incorporating digitally produced casting models into their production processes at levels never seen before. Machine costs have dropped dramatically, and makers now have a wide variety of 3D printers and materials from which to choose. None of these are qualitatively identical, and there is a significant body of evidence, both anecdotal and documented, indicating that materials used in digital production have varying degrees of success in investment casting. The root causes of related defects are not fully understood, leaving the industry plagued by speculation and a variety of home grown methods aimed at addressing these problems. Through the use of controlled studies, we first explore the burnout behaviors of several mainstream materials, followed by an evaluation of dimensional movement experienced by these materials when subjected to investing and firing. Casting defects will be tracked to their root causes through dimensional analyses and observations of defect morphology in cast product.

Understanding the properties and improving the processing of silver alloys

Franz Held FEM (Forschungsinstitut Edelmetalle + Metallchemie)

Silver alloys are widely used in jewelry and are showing some distinct production issues. The paper aims to provide guidelines to the manufacturer of silver products as well as to the goldsmith to achieve high quality products with reduced reject. At first an overview on the metallurgy of silver and silver alloys with a focus on some specific properties of silver, for example the high gas permeability, will be given. These specific properties are the reason for many production problems such as fire scale or different type of porosity. The variation of the silver content in the typical range from 925-935Ag and the role of alloying additions will be highlighted. The metallurgical basis will provide guidelines to the define conditions for the manufacturing of silver products by different processes, such as melting & casting, hot and cold deformation, annealing, quenching, ageing and brazing. Typical failure sources will be identified and illustrated by examples of defective samples. As a consequence the requirements on alloys, equipment and processes will be described and proper working conditions in industrial production as well as in the goldsmith’ workshop will be given.


Andrea Friso Product Division Manager - Legor Group S.p.A. - Bressanvido VI - IT

The present work aims to provide a list of the most common questions made from the customers according to our experience on technical assistance, in terms of information on products (master alloys for gold and silver production) and on jewellery production processes. A particular focus will be given to the answers that were provided and of the implications in the everyday life in production departments.