Trial: Development of Zero Defect Coating Technology for the Watch Industry

Project: Research

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The tradition surface treatment techniques include electroplating and organic coating, etc. However, they can no longer satisfy the stringent requirements of modern designs. Recently the rise of plasma technology and nano-materials provides a feasible approach for the surface modification of components. The objective of the present development program is to prepare a homogeneous, dense and transparent coating to protect the watch surfaces by means of a new vapor deposition technique. As a result, the surface hardness can be superior to that of sapphire, which will improve substantially the wear resistance and endurance of watch surfaces. In addition, the coating can prevent the surface corrosion caused by some external factors such as climatic change, sea water and sweating, thus keeping the original brightness and luster, or even making the appearance more elegant and upscale. In this study, a pilot facility for thin film deposition will be set up, and the coating processes as well as the structure and properties of the deposited thin films will be studied in details. Based on this, we’ll provide the technical service for the watch industry. Meanwhile, we’ll hold seminars/workshops to promote the new watch products with the protective coatings as well as their superior properties. Deliverables achieved: 1. Develop a new vapor deposition technology to apply homogeneous and defect-free coatings on watch surfaces for protection. 2. The coatings are adherent to metallic substrates. 3. The surface hardness of the coatings can exceed that of sapphire (24 GPa), and the coatings are chemically inert and optically transparent in the visible light range. 4. Small-scale production can be realized by means of the designed prototype coating facility for the watch products from the local industry. 5. Patent application for the technique to prepare hard and transparent coatings on watches. Through continuous efforts, we have made a breakthrough to develop a new technology (pulsed CVD) to apply hard and transparent coatings free of pinholes on precious metal objects of complicated shape, which cannot be realized by PVD technologies. The wear, oxidation and corrosion resistance of the metals can be improved substantially. For this reason, a US patent and a China patent have been filed based on our research results. The main goals in this ITF project have been achieved. Our findings indicate that the pulsed CVD technology not only provides the protection for Au-Cu alloys but also for other precious metals such as silver. Therefore, the applications can be expanded to more areas such as watches, jewelries, molds, lenses, glasses, display devices, and medical implants, etc. After the completion of this ITSP-TCFS project (Ref. GHP/048/12), we plan to apply the Public Sector Trial Scheme (PSTS) under ITC, which provides funding support for production of prototypes/samples and conducting of trial schemes in the public sector to facilitate and promote the realization and commercialization of R&D results. In fact, the scheme is designed to assist in the application of R&D results in the real world and facilitate further development and refinement of products in meeting the needs of eventual clients. As a non-profit-making association, the Federation of Hong Kong Watch Trades & Industries Ltd will support our team in many industrial trial tests on different products, including watches, jewelries, molds, and many other metal components. The feedback will be important for CityU to further modify the coating processes and increase the productivity. As there are a wide variety of watch and jewelry products, it is expected that the trial tests will be carried out for 24 months, based on the mutual cooperation between CityU and the Federation. The success of this development project will be a crucial step in enhancing the product quality and competitiveness for Hong Kong’s pillar industries. The implementation and commercialization of the project on hard and transparent coatings will be indispensable, and the outputs arisen from this project will lead to new growth points in the manufacturing industries. This is absolutely a good chance for the watch industry to upgrade their products. If successful, many members in the Federation will become the first users of this coating technology.


Project number9440185
Effective start/end date1/11/17 → …