Formulation And Recycling Of Investment Casting

Preparation of molds
The purpose of preparing the mold is to mix the various raw materials that make up the mold into a uniform whole, and to make the state of the mold meet the requirements of the pressed investment group.
In the preparation, the heating method is mainly used to melt and mix various raw materials into one, and then in the case of cooling, the mold is vigorously stirred, so that the mold becomes a paste state for pressing the investment mold. Sometimes there are cases where the mold is melted into a liquid and the investment is directly poured.
Recycling of molds
When using resin-based moldings, due to the high quality requirements for the investment casting, most of the new materials are used to formulate the mold to press the investment of castings. The mold material recovered after demolding is used to make the investment of the sprue system after remelting filtration.
When using wax-based moldings, the resulting molds can be recycled and used to make new investment molds. However, during recycling, the performance of the mold will deteriorate, the brittleness will increase, the ash will increase, the fluidity will decrease, the shrinkage rate will increase, and the color will change from white to brown, which is mainly related to the deterioration of stearic acid in the mold. Therefore, in order to restore the original performance of the old mold as much as possible, it is necessary to remove soap salts from the old mold, and the commonly used methods are hydrochloric acid (sulfuric acid) treatment, activated clay treatment and electrolytic recovery.