Saturday, 11 May 2013

Jewellery Manufacturing


AESERA  Jewellery DESIGNING ACADEMY

No 144/74, Eskay building, 3rd floor,
Greams Road, Thousand Lights
Chennai,  Tamil Nadu
India,
Mobile: +91-9444100081,+91-9840689781

seshu.gopal@jewelrydesignacademy.com



A piece of jewellery begins as a figment of the imagination. It takes years of training for a designer to translate this thought onto a design platform. He has to learn the intricacies of jewelry design and drawing and have an understanding of all of the various precious metals and stones that are included in the product. A designer also requires an understanding of how to balance various metals with gemstones to create a viable product. Also, creating trendy or value-driven designs requires extensive industry and market knowledge.



A skilled craftsman with many years of experience transforms a two-dimensional drawing into a three-dimensional wax model. Many varieties of wax exist, each developed for a particular application. Some wax is designed for carving, while others are cut from sheets, and are heated and fashioned by numerous methods to define shapes and details in the wax.







Lost-wax investment casting was established in the early 1900s in the dental industry. It soon became the leading method of creating reproductions because of its increased accuracy over existing methods. It soon evolved into a process for jewelry, where it has grown to be the dominant form of mass production. The goal of lost-wax investment casting is to create wax copies that allow mass production of items identical to a handmade original.
It begins with a piece of metal jewelry called the model. In order to make a rubber mold, one must cover the metal model with a solid layer of unvulcanized rubber and subject it to pressure and heat. Then, using a very sharp knife the rubber mold is dissected and the original model is removed.

Molten wax is then injected into the resulting rubber mold – a process that can be repeated to produce mass numbers of the original model.
Next, the wax models are placed on a sprue. The term "sprue" generally refers to a wax rod, or series of rods, that secure a wax model to a specifically configured rubber or plastic base. Once the waxes have been securely attached to the sprue base using sprue rods, a stainless steel flask is carefully inserted inside the outer lip of the sprue base, so as to surround the waxes while still leaving, minimally, a quarter inch space between the wax and the inside of the flask.
Investment, a material that resembles plaster of Paris, is poured around the wax models to completely fill the open spaces.
After the investment has set, the sprue base is removed and the object is placed inside of a kiln. This process is called the burn out. The temperature of the kiln is slowly raised to an excess of one thousand degrees Fahrenheit, completely “burning out” the wax to leave a mold.
Once the investment is thoroughly cured, the temperature is brought down to a specific temperature and allowed to settle before pouring in the liquidized metal. As a general rule, the greater the detail and the finer the areas the metal must fill, the hotter the flask needs to be in order to allow the metal to completely fill the voids where the wax was before the metal freezes. Once the flask has cooled, the investment is removed, leaving a rough version of the original design.

Although lost wax casting is still the dominant form of mass production, new technologies, such as rapid prototyping, offer future promise to reduce manufacturing time and costs associated with the lost wax method.

Now that a raw piece of jewelry has been removed from the kiln, there are various processes required to give the piece a finished look. The goal of the final steps of finishing is to achieve a bright, mirror-like polish that is free of any visible abrasions, dents or irregularities. The polishing stage requires many different types of wheels that are used for particular applications, such as corners, flat surfaces, and difficult to reach areas. Polishing is the final abrasion or smoothing of karat gold before buffing. It leaves a dull finish and removes visible traces of sanding or other abrasive procedures. Next, lapping is a step in the polishing process for karat gold jewelry that has sharp corners or flat surfaces. Lastly, buffing creates the mirror-like finish and causes little-to-no metal to be removed. It is the final step in the professional finishing process.

Adding gemstones and diamonds to the finished casting is a very delicate process. The art of setting requires years of training. An accomplished setter is adept at protecting the gemstone while securing it tightly into the ring. There are multiple types of settings that secure the stone in the finished casting. Diamonds, for instance, may be set in seven different types of settings, each displaying the diamond(s) in different ways.
Bar: Metal bars hold the loose diamonds in a channel-like setting.
Bezel: The metal is formed tofit around the diamond, cupping it into place.
Channel: A row of smalldiamond stones are set in a groove in the diamond rings.
Chevron: V-shaped prongs thatusually hold a marquise or princess-cut diamond for solitaire style rings.
Invisible: Diamond set in agroove without visible prongs.
Pave: Tiny stones are embeddedto look like the piece is paved with loose diamonds.
Prong: Several prongs hold thediamonds to let light pass through without interference.

The final stage of manufacturing includes the finishing touches that assure the customer a quality product. Rhodium or gold plating may be added to the product to enhance its attractiveness, followed by a thorough cleaning process. After adding a trademark symbol to the finished product to identify its origins, the product goes through a rigorous quality control process. This process is in place to ensure that there are no scratches or pits in the metal, no broken or loose stones in the setting, and no rough edges on the prongs. Once these qualifications are met, the piece of jewelry is ready for shipping.


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