1. New process for processing on the embryo cake:
Generally speaking, there are two situations in which the blank cake needs to be pretreated: one is that the shape of the product such as a rectangle is irregular, and the other is that the pattern of the product is irregular. By increasing or decreasing the amount of metal in some parts of the blank cake, the blank cake can flow more evenly during imprinting, which is beneficial to the pressure of the product pattern. For example, when the Yangtze River Three Gorges gold and silver coin was developed in 1995 and the Dragon Year Zodiac fan-shaped gold and silver coins were developed in 1999, the pretreatment of the blank cake was carried out, which solved the problem of insufficient four-corner pressure and four-sided starting line during imprinting. The problem is that the production of rectangular or fan-shaped shaped gold and silver coins has been successful.
2. Deep corrosion treatment on the embryo cake:
Compared with gold coins, silver coins are more prone to oxidative discoloration. One of the reasons is that there are trace impurities on the surface of the silver cake during the production process. The etch-treatment of the cake is to use a certain ratio of acid solution to process the surface of the silver cake to remove trace impurities on the surface of the silver cake to effectively prevent discoloration of the silver coin. In 2000, when the Dunhuang Flying Silver Coin was produced, the silver billet was deeply etched.