Jewelry Manufacturing

Jewelry Guide – Jewelry Manufacturing

Jewelry making is the art of creating jewelry by using various tools and techniques and when this is done on a large basis for commercial purposes, it is known as mass jewelry manufacturing.
Process of Jewelry Manufacturing
The process of jewelry manufacturing or jewelry making involves following steps:
Designing
Jewelry designing is the process of creating, crafting, producing or rendering designs for jewelry. Jewelry designing is the preliminary step to manufacture any jewelry item. Jewelry designs are usually created or crafted by a jewelry designer, a professional who is trained in the jewelry architecture and hold functional knowledge of metallurgy and design elements such as composition and wear-ability. These designs are created on the basis of future trends and customer’s taste in selected target market.
Casting
Casting is a widely used jewelry manufacturing process, in which a molten material such as metal, plastic or any other material is poured or forced into a hollow mold and allowed to solidify within the mold and then ejected or broken out to get a fabricated jewelry part. A jewelry part, which is created through casting, is slightly more porous with a rough surface and requires additional polishing and finishing. Usually casting is used for making complex shaped jewelry parts that would be difficult or uneconomical to be made by other techniques, such as cutting from solid material.
Pre-Casting Requirements

Process of casting requires following requirements to be finished:

  • Creation of Mold / CastCreation of cast or mold is first and foremost requirement for casting. Mold is the reverse shape of the jewelry part which is made from a refractory material, for example, sand. Molds can be created, either for temporary use or for permanent use.
  • Creation of Metal AlloyGenerally in making jewelry, precious metal such as gold is not used in its pure 24 karat form due to its softness. In such a case, metal is melted and mixed with other hard metals like copper, silver and nickel to obtain the desired karat specification.
Methods of Casting

Casting can be done by using various methods and some of these popular casting methods are described as under:

  • Lost Wax CastingThis is one of the most commonly used casting techniques. Under this casting method, an object is made of wax and coated in clay. When the clay is fired, the wax melts and is drained away or evaporates leaving an exact impression of the object in the hardened clay, which is then filled with molten metal.
  • Sand CastingThis is the oldest and most popular casting technique. Under this technique, natural sand (lake sand) or green sand (mixture of sand, clay and some water) is packed onto wood or metal pattern halves, removed from the pattern, and metal is poured into resultant cavities. And finally, mold is broken to remove casting. This technique requires a lead-time of days to obtain castings.
  • Shell-Mold CastingShell-mold casting is similar to sand casting except that a mixture of sand and 3-6% resin holds the grains together. The process is useful since it is very cheap and yields good surface finish and complex geometry. Under this technique, firstly a two-piece pattern is made of metal, which is heated and coated with silicone spray. Each heated half-pattern is covered with a mixture of sand and resin binder. The binder glues a layer of sand to the pattern, forming a shell. The pattern is removed once the assembly is baked and then the two half-shells joined together to form the mold. Molten metal is poured into the mold and when the metal solidifies, the shell is broken to get the part. The sand-resin mix can be recycled by burning off the resin at high temperatures.
  • Plaster-Mold CastingPlaster-mold casting is also similar to sand casting except that plaster is substituted for sand. Plaster compound is actually composed of 70-80% gypsum and 20-30% strengthener and water. The plaster cast can be finished to yield very good surface finish and dimensional accuracy. Plaster casting is normally used for nonferrous metals such as aluminum or zinc or copper based alloys. It cannot be used to cast ferrous material because sulfur in gypsum slowly reacts with iron. Once used and cracked away, normal plaster cannot easily be recast.
  • Ceramic-Mold CastingCeramic-mold casting is similar to plaster-mold casting except that ceramic material is used instead of plaster. This method also provides very good quality castings.
  • Die CastingDie casting is the process of forcing molten metal under high pressure into the cavities of steel moulds. The molds are called dies. These dies are reusable and able to provide very complex shapes also.
  • Centrifugal CastingCentrifugal casting is the process of casting in which molds are attached to the outside edge of hollow tube. Metal in liquid form is poured into the tube and it is spun at high-speed centrifugal force that pulls the molten metal into the molds.
  • Continuous CastingContinuous casting is a casting process in which metal casts are produced on continuous basis. In this process, liquid metal is poured in a mould from one end and that metal is solidified immediately and comes out as a metal cast from the other end. This process generates metal casts with uniform chemical composition and properties.

Devestment

Devestment is the process of removing the casting investment from the casting flask and tree. Generally two methods, such as wet devestment and dry devestment, are used for this. In wet processes, water is used to break apart the investment while in dry processes, a flask-stripping device is used to push and shake the investment.FinishingFinishing is the process in which surface of a piece is cleaned or polished or textured. Finishing is the most important step of jewelry manufacturing process and usually all jewelry items require finishing. Finishing is very essential part of a jewelry manufacturing process as it gives beauty and brilliance to a jewelry piece. Finishing is achieved under various stages, which are described as under:

Metal Finishing

Metal Finishing covers any operation or activity that alters the surface of a metal piece to achieve a certain property or look. Metal finishing is preformed after a metal cast has been formed. Metal finishing covers many processes like cleaning, soldering, plating, texturing etc. These processes are described in detail under Stone Setting & Finishing Guide.

Stone Finishing

Stone Finishing covers any operation or activity that alters the characteristics of the gemstone to achieve a certain property or look. Stone finishing is preformed after a gemstone is mined. A well cut and polished stone is considered to have a beautiful finish. Some of the popular stone finishing ways are described in detail under Stone Setting & Finishing Guide.

Stone Setting

Stone Setting is an art of securely attaching or fixing a gemstone into jewelry with an aim to display maximum beauty of a stone. Each and every piece of jewelry that contains a gemstone has a setting and this setting plays an important role in enhancing the charisma of a jewelry piece. Jewelry designers have developed various fascinating methods of stone setting like prong setting, bezel setting, channel setting, pave setting, tension setting etc. These settings are described in detail under Stone Setting & Finishing Guide.