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Dewaxing Casting, One of the Forming Methods for Glass Processing

Date

  • Apr 6, 2019

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Dewaxing casting is one of the glass forming methods. The main process of dewaxing casting is to heat the glass to high temperature to make it fluidity and flow into the prefabricated shell to form. Because the shell is made by removing wax mould after heating, it is called dewaxing casting.


Because the glass containing lead oxide (commonly known as artificial crystal) has diamond-like high refractive index and high fluidity at high temperature, artificial crystal is often used as material for casting glass. In the Chinese market, the dewaxing cast lead crystal glass products mentioned above are generally called glaze. The complex and exquisite crafts can be produced by dewaxing casting. [1]


Dewaxing Precision Casting Method: Dewaxing casting process was developed from ancient casting process. In the late Neolithic Age more than 5000 years ago, the lost wax casting technology was widely used in the manufacture of bronzes by ancient craftsmen in China. According to the plasticity and thermal volatility of beeswax, the craftsmen at that time carved beeswax into wax molds of desired shape, then wrapped clay around the wax mold and reserved a small hole. After drying, they roasted the wax mold to vaporize and volatilize. At the same time, clay became a ceramic shell, leaving a negative wax mold on the inner wall of the shell. Then the molten metal is injected into the shell along the small hole, and the shell is broken after cooling, that is to say, the required metal billet is obtained. The basic principles of modern wax-loss casting technology are no different, but more complex and precise. This is mainly reflected in the more stringent requirements for the precise position of the wax pattern. In modern technology, wax pattern can be obtained not only by directly carving wax, but also by pressing the metal prototype (plate) with silica gel, and then by wax injection with silica gel. Casting materials are no longer clay, but cast gypsum. Such products are much finer than ancient castings.