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Environmental friendly production of hollow jewels using a polymer core

Objective



The production of the hollow jewels by etching is linked to heavy economic and environmental impacts and poor working conditions. During the process a layer of gold is put on a wire of common metal like copper or brass (coated wires). After having obtained its final shape, the common metal is eliminated by chemical dissolution with nitric acids (etching process). This process is essentially applied to produce hollow chains. The objective of the project is to replace the core of copper by a composite one (polymer and reinforcement) with the same product quality for the final jewel. The objectives of this project are: 1. Total control of the final jewel fineness. No more enrichment of the gold alloy which is due to thermal diffusion between copper and gold. Today, it is impossible to predict the final fineness. To avoid problem with authorities due to a lower fineness than indicated, the companies are today applying a fineness which is systematically too high. Expertshave noted an average fineness of 780 for thousand for gold jewels instead of the 750 %0 legalfineness. This causes important losses. 2. Total suppression of polluting effluents (both acids and heavy metals). The polymer core will be eliminated by a simple thermal treatment. The elimination of nitric acid in the process of etching will improve health and safety conditions (absence of nitrous vapors, concentrated acids...) and allows the companies to participate to new standards concerning the protection of the environment like the EU-ECO-Audit Scheme ISO 14 000 The project will decrease the costs per part of hollow jewels between 5 and 10%. This will improve the competitiveness of the industrial partners and security will be given to a important number of jobs in this branch. During this project it will be worked on the cause of the ecological impacts (copper dissolved by nitric acid) and not on the development of expensive "end-of-pipetechnologies". The new technology combines economical and ecological problems according to the principle of Sustainable Development. The intended project is included in the BRITE-EURAM areas. The subject covered by the proposal are area l. l .l.S, 1.2.1.S and 1.2.2.M.

Funding Scheme

CRS - Cooperative research contracts

Coordinator

Sauvat S.A.
Address
11,Avnue De La Gare
43103 Brioude
France

Participants (10)

CENTRE TECHNIQUE DE L'INDUSTRIE HORLOGERE
France
Address
39,Avenue De L'observatoire 39
25003 Besancon
Carmafix S.A.
France
Address
Z.i. Rue Ducros
23000 Guéret
FORSCHUNGSINSTITUT FUER EDELMETALLE UND METALLCHEMIE E.V.
Germany
Address
17,Katharinenstrasse 17
73525 Schwaebisch Gmuend
FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V.
Germany
Address
Joseph-von-fraunhofer-strasse 7
76327 Pfinztal
Filk SpA
Italy
Address
10,Via S. Giuseppe
36065 Mussolente
Franz Breuning KG
Germany
Address
60,Luisenstrasse
75172 Pforzheim
Max Oro S.p.A.
Italy
Address
4,Via 2 Giugno
52048 Monte S. Savino
NATIONAL RESEARCH COUNCIL OF ITALY
Italy
Address
Corso Stati Uniti 4
35127 Padova
Nuova Catena S.r.l.
Italy
Address
1,Via Lugana
36065 Mussolente
R. Platnauer Ltd.
United Kingdom
Address
Austin Way - Old Walsall Road
B42 1DU Birmingham