20 | JNA July/August 2024 INNOVATION 创新科技 | Bernardette Sto. Domingo 杜明高 | Recent advancements in platinum electroforming are pushing it closer to becoming a mainstream jewellery manufacturing process that could bring about fresh business opportunities and bolder, more inventive jewellery designs. 铂金电铸技术的进步， 使其更合乎主流珠宝制造工序，开拓崭新商机和创新珠宝设计。 Electroforming as a manufacturing technology has been around for quite a while – for gold jewellery, that is. Today, endeavours to replicate its application and success in platinum jewellery production are gradually breaking ground. A joint study on “Improvements in Platinum Electroforming” by Platinum Guild International (PGI®) and Pino Aliprandini SA revealed that recent advances have addressed some challenges to platinum electroforming, but limitations remain. Finetuning its performance and feasibility can thus open new opportunities in the platinum jewellery marketplace, the study said. Roadblocks The electroforming process – an established and widely used gold jewellery-making method – involves electroplating a three-dimensional shape (mandrel or model) and depositing multiple layers of metal while soaked in an electroforming solution or bath. As electroforming produces hollow jewellery pieces that are lighter in weight, a wall thickness of at least 150-plus micrometres (microns) must be achieved – a process that builds up internal stress, which then leads to brittleness. It is also more difficult to convert platinum to a suitable “complex” for electroforming although a few suppliers, Pino Aliprandini included, are actively developing innovative solutions. Perhaps the biggest hurdle to cost optimisation and mass production is short bath life. A platinum bath can typically last for three to five turnovers before signs of deterioration start showing on electroformed surfaces. When the bath expires, it needs to be recovered and the platinum refined, which adds to the cost. By comparison, gold baths have a much longer bath life and can easily be replenished and regenerated. Impurities and operating parameters such as pH levels, temperature and current density are significantly more sensitive in platinum solutions, according to the study. “The cost of running a platinum bath, aside from metal cost, is substantially higher than that of gold electroforming,” the study read. “The latest research on platinum jewellery electroforming is focused on extending the bath life to increase production efficiencies and make the process more sustainable.” Brilliant possibilities Renewed interest in further developing platinum electroforming has resulted in significant inroads. At present, only a few electroforming systems are actively doing research and development and running tests to resolve quality issues for platinum jewellery production. Initial trials in 2020 were promising, with samples achieving 200-plus microns in thickness, excellent surface quality, high brightness, and minute signs of brittleness. However, operating at higher parameters of platinum concentration, pH, temperature and density alongside quicker processing time resulted in the rapid build-up of internal stress and critically shortened the bath life. More recent trials in 2023 and 2024, which operated at lower parameters with modified platinum salts, successfully contained internal stress to a minimum and enabled consistent quality. The test baths achieved reusability of over 10 turnovers without signs of deterioration on the electroformed surface. platinum electroforming Bright prospects in 铂金电铸前景平坦开阔
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