Product samples are hollowed by the removal of wax in the furnace.
Technological breakthroughs
Returning to Hue in 2011, Nguyen Phung Son, manager of Nguyen Phung Son bronze-casting facility (located on Huyen Tran Cong Chua Street, Phuong Duc Ward, Hue City) continued to pursue his forefathers’ bronze-casting tradition lasting more than 25 years.
Since moving his facility from Dong Nai to Hue, Mr. Son has cast such traditional products as bells, statues and a number of delicate fine arts articles of various weights and sizes. Apart from making the guild’s reputed products, Mr. Son is following the current trend towards handicrafts and souvenirs production by investing in technology line to cast small bells, cultural icons, statues of luminaries, and patriots filling the needs of souvenir service.
Shifting into mass-production means that this new manufacturing model is required to create a large quantity of standardized products using high technology. As a result, Mr. Phung Son decided to purchase investment castings (lost-wax casting) and various supporting machines like wax injection, mold making (mold is a mixture of water, adhesives and clay replacement materials), sandblasting, wax separator, etc. Compared to traditional technology of manual process, this new production line provides mass manufactures.
This continuous producing system also includes electric kilns and two electric metal melting furnaces for 200kg to 500kg copper casting. In most old style foundry, during this stage of metal melting much smoke, dust, toxic gases will be generated, creating negative impacts on workers’ health and surrounding environment. Thanks to the new technology using 100% electricity, those furnaces have overcome these disadvantages.
Since electricity is used in most stages from mold designing, firing, to copper melting to create raw products, environmental pollution issue is under control. According to the business owner, when electricity instead of wood, charcoal burning is used, the producing cost from investment casting process is reduced by 10-15% compared to traditional casting methods. In the stage of copper melting alone, using wood and charcoal will cost him around VND5-6 million/ ton, whereas the cost is cut down to about VND2 million /ton when utilizing electricity.
Though everything is in completion stage, the series of forthcoming bronze casting products show that Mr. Nguyen Phung Son’s changing direction into new technology is a way to get ready for the diversification of Hue traditional souvenir products, meeting the needs of increasing local tourism services. Having a strong desire to launch in the market various types of unique bronze casting products, Mr. Nguyen Phung Son is expecting to get his products ready for shipment in early 2018.
Production scale-ups to meet market demands
Mr. Nguyen Phung Son said that investment casting had many advantages. It produces good quality products with high dimensional accuracy and level of details. Also, much of the wax is reclaimed and reused, leading to lower costs of molding materials and environmental pollution minimization. With the existing scale of production, if the investment casting process achieves full capacity utilization, the facility can produce 5 tons of products per month. This new production line offers a clear advantage to workers’ health and well-being since it is safer and friendly to most types of workers. So far, five female employees in a total of 10 employees have been responsible for the early stage steps of the production process.
To achieve cost efficiency, this technology should be used in mass-production creating large volumes of products. Therefore, this manufacture process is considered to be new in Hue, though, if any facility is able to find potential markets, they can invest in a similar technology line producing large quantities of products meeting market demands.
At present, there are 64 facilities in the bronze-casting guild of Phuong Duc Ward and Thuy Xuan Commune. Of these, only 4 facilities and 1 cooperative are installing smoke and dust collectors using misting systems- a technology transferred by Thua Thien Hue Department of Science and Technology- Advanced Science and Applications Center. Most of other facilities directly discharge dust and smoke into the environment without any form of treatment. In reality, if all required conditions are satisfied, facility owners can invest in electric furnaces to cast products that are big in size like big bells instead of using furnaces utilizing wood and charcoal to reduce hazardous smoke and dust emission.
Mr. Nguyen Tien Long, Vice Chairman of People's Committee of Phuong Duc Ward said that every year the facility managers were asked to make a solemn pledge and promise not to use rubber, waste oil as heating fuel and were encouraged to choose to cast during good weather days. Therefore, fewer people living around the area complained about the pollution issue. People working in foundries themselves are very conscious of ways to minimize pollution to firstly protect their own family and relatives.
Story and photo: Hoai Thuong