The following issues should be paid attention to in the operation process of planting wax trees.

1) There is generally a 45° angle between the wax model water channel of the wax tree and the wax stick, that is to say, the direction of the wax model is inclined upward. Only in this way can the gold water be injected into the plaster mold smoothly. This angle can be adjusted appropriately according to the size and complexity of the wax model. Small and complex wax models can reduce the included angle; on the contrary, larger wax models can increase the included angle.

2) Before planting wax trees, the rubber chassis should be weighed first. After the wax tree is planted, it is weighed again. The weight of the wax tree can be calculated by subtracting the results of these two weighings. Converting the weight of the wax tree to the weight of the metal by the ratio of the density of the paraffin to the cast metal gives an estimate of how much metal is needed for casting.

3) After planting the wax tree, it is necessary to check whether the wax model has been welded firmly. If it is not welded firmly, it is easy to cause the wax mold to fall off when pouring plaster, which affects the casting process. Finally, it should be checked whether there is enough space between the wax models. If the wax models are attached together, they should be separated; if there are dripping wax drops on the wax tree, they should be trimmed with a blade.

Shell type

The baking of wax mold is an important process to ensure the normal operation of casting. Generally speaking, the mold baking time for 18K gold is 6 to 12 hours, and the mold baking time for platinum is 12 to 20 hours. The main functions of baking are: dewaxing, drying and casting insulation. Taking the baking of 18K gold as an example, the dewaxing temperature is 0~350℃, and the holding time is 2 hours; the drying temperature is 350~700℃, and the holding time is 2~3 hours; the casting temperature is 600~500℃, and the holding time is 1~3 hours. 2 hours.

Since glass containing lead oxide (commonly known as artificial crystal) has a high refractive index like diamond and high fluidity at high temperature, artificial crystal is often used as the material for casting glass. In the Chinese market, the above-mentioned lost-wax cast lead crystal glass products are generally called glaze. The lost-wax casting method can produce complex and exquisite handicrafts. [1]

Lost wax casting method: The lost wax casting process is developed from the ancient casting process. In the late Neolithic Age more than 5,000 years ago, ancient Chinese craftsmen widely used the lost wax casting process in the manufacture of bronze ware. According to the characteristics of beeswax's plasticity and thermal volatility, the craftsmen at that time first carved the beeswax into a wax mold of the desired shape, then wrapped clay and reserved a small hole outside the wax mold, and baked it after drying to make the wax mold vaporize and volatilize. At the same time, the clay becomes a ceramic shell, and the inner wall of the shell leaves a negative mold of the wax mold. At this time, the molten metal is injected into the shell along the small hole, and the shell is broken after cooling to obtain the required metal billet. The basic principles of modern lost-wax casting techniques are the same, but more sophisticated. This is mainly reflected in the stricter requirements for the precise shape and position of the wax model. The acquisition of wax mold in modern technology is not only the direct engraving of wax, but also the negative mold can be obtained by molding the metal original mold (plate) with silicone, and then the wax mold can be obtained by injecting wax from the silicone negative mold. The casting material is no longer clay, but cast plaster instead. Such products are much finer than ancient castings.