Journey from Gold Bullion to Jewellery
The jewelery industry is sensitive to changes in consumption habits, unstable, labor-intensive, and predominantly uses traditional technologies. In other words, we can describe it as the place where creativity and handcraft meet. Although the raw material in the jewelry industry is not only gold, but also other precious metals such as silver, platinum and copper, the decisive factor is gold. Like other metals, gold is made available for the manufacture of jewellery, either by mining or by recycling previously processed gold.
Gold coming from both mining and recycling is poured in refineries as gold ingots. These ingots enable semi-finished products to be processed by hand or machine to reach the final product. Afterwards, semi-finished products are obtained in rolling or profile benches and then they are formed into different shapes.
First, platinum, gold, silver, or their alloys are melted and poured into the pre-prepared mold, then the parts coming out of the mold are forged, punched, held under pressure, thinned, etc., in accordance with the design through shaped. Sometimes only one or all of these techniques are used in the manufacture of jewellery. These operations are simply as follows:
-The process of shaping the materials by passing them between two or more rollers is called rolling. By rolling, the thickness of the materials is changed or made into different profiles. The basis of rolling is the process of bringing the material passed through the rollers, whose axis is parallel to each other and opposite to each other, to the desired shape. Pre-annealing should be done to facilitate the shaping process. In the rolling process, the materials are passed through the rollers several times until they reach the desired thickness or shape.
-Hardness occurs in rolled materials. Intermediate annealing should be done to remove this hardness. Annealing is the heating of the material to a temperature below its melting temperature. With annealing, the hardness of the material is removed, and the cracks on the material surface are prevented.
-The process of physically joining two metals of the same or different kind by using an additional metal under the influence of heat is called welding.
-Products should be immersed in hot sulfuric acid solutions in order to clean the oxidation or slag adhering to parts during the welding process. Nitric acid, hydrochloric acid, sulfuric acid, and kitchen salt are used for this cleaning process, which must be done before galvanizing or coating. After the parts are welded, they are immersed in these solutions and the surface of the part is cleaned from some dirt. This is called polishing.
– Sandblasting is a process performed to make the surface of the product cleaner and more beautiful, and to reflect the light more. With sandblasting, the parts gain shine in natural appearance.
-Marking is the process of drawing the production picture of a work to be done on the workpiece.
-Casting is the shaping process by pouring liquid metal or metal alloys into the previously prepared mold cavity. The basis of foundry is to save the time required for production in cases where a previously made jewelery needs to be repeated or when a large number of products are required.
-Then the product that comes out is taken from the casting machine, separated from the plaster, and the cleaning process is completed after cooling. Finally, the waste generated during production is calculated. Since the material values of the metals used in the manufacture of jewelry are high, wastage and their recycling are very important.
After all these production stages are completed by the masters, the jewelry is ready for sale. The jewelry begins to wait on its shelves in store to make its owner happy.