Saturday, 19 July 2014

Manufacturing Processes for Jewelry


For centuries, jewelry has been used for personal adornment. Jewelry is a symbol of status, power, love, friendship and romance. The finished piece of jewelry that we take utmost pleasure in wearing comes to us as a result of elaborate and intricate methods of manufacturing.

Jewelry manufacturing is an art in itself, right from conception of an idea to its execution. As a designer or even as a consumer it is essential to have knowledge of how jewelry is manufactured. From the point of view of a designer it is extremely important to ensure that designs sketched stand true to the test of practicality. A good looking design might not be a practical one! And from the point of view of a consumer it is important because of the price variations that come in due to the method of manufacturing. For example if a piece of jewelry is hand crafted it will demand a higher price because the process is very laborious and slow. Whereas, a casted piece of jewelry will demand a lower price because casting is a method used for bulk production.
Further listed below are various methods of manufacturing jewelry.

HAND FABRICATION/BENCH- MADE: it is the most ancient method which is used to make jewelry. In this method the piece is manufactured manually using various techniques such as sawing, filing, annealing, soldering, setting and finishing. It is a dying art because it takes the most skill and time but it yields the highest quality of finish possible.
PROCESS OF HAND FABRICATION
ADVANTAGES:
  • It promotes creativity as design options are unlimited.
  • It is able to exhibit the skill and work of each craftsman individually.
  • It requires less cleaning and finishing.

DISADVANTAGES:
  • It is a very time consuming process.
  • The cost of production is high.
  • It is a laborious process.

LOST WAX INVESTMENT CASTING: this method is believed to be more than 5000 years old. In this process a duplicate metal sculpture is casted from the original piece.
First and foremost in this process a master piece which one wishes to replicate is needed.
The master is then sandwiched in between two silicone sheets under extreme heat and pressure.
In heat silicone becomes hard and rubbery. After cooling, master is cut out and the mould is separated in two halves.
Melted wax is then injected under pressure in the mould.
After cooling wax model is removed. Various such models are created.
These are then attached to a wax tree. Many parts can be casted on a single tree wax.
Then a flask is fit over this tree and then investment (plaster of Paris) poured into the flask. The POP mix before being put in the flask is put in a vaccum to remove all air bubbles. It is then left for setting which takes about fifteen minutes.
After pouring the POP mix, the flask is again put in the vaccum. Then the flask is put in a furnace. As a result wax melts out creating a cavity in the plaster.
Then the flask is inverted and with the help of the hole at the base of the tree molten metal is poured in the flask. Then the flask is cooled by plunging it in cold water.
Once the flask is out solidified metal pieces are clipped from the tree and are cleaned up. Next step is filing and polishing
MASTER

WAX TREE AND INVESTMENT

MELTING WAX IN FURNACE AND POURING METAL

ADVANTAGES:
  • It is relatively a quick way of making identical pieces. Thus, it is a time saving process.
  • It turns out to be economical when many pieces are produced from the same mould.
  •  It provides unlimited design possibilities.

DISADVANTAGES:
  • Cast metal is less suitable for fine engraving because of porosity.
  • It requires more cleaning and finishing than other methods.

ELECTROPLATING: electroplating process originated in 1830’s. This turned out to be an accurate and convenient method to reproduce antique objects. This method originally required a very high Karat of gold, which was about 23.5K. But with technological advancements it was done with 18K and 14K gold. From then this method became very popular.
Electroplating can be defined as a process of depositing precious metal over another less expensive metal. It is usually used to produce light weight jewelry.
For electroforming firstly, the metal which is to be electroplated is thoroughly cleaned and dipped in distilled water. Then this piece is attached to the negative cathode.
Then in a container the electroplating solution is filled which is called the electrolyte. In this electrolyte the metal to be deposited is put. Now the negative cathode and positive anode is immersed in the electrolyte.
The current is then switched on. The whole apparatus is connected to a rectifier which changes the alternative current from a normal plug to direct current. This conversion is important since alternating current is stronger and it might burn the metal.
From here on, the deposition process begins. Slowly the metal piece is coated with a thin layer of depositing material.
ELECTROFORMING
ADVANTAGES:
  • This process is helpful in creating costume jewelry.
  • Electroformed pieces are able to exhibit fine details and minute engravings.

DISADVANTAGES:
  • Electroformed pieces dent easily. Once such pieces are dented or broken it is not possible to repair them.
  • Cost of production is high due to expensive equipments.
  • Electroformed jewelry is not suitable for stone mountings.

STAMPING: it is a procedure in which the metal is pressed between steel dies in a hydraulic press at very high pressure for industrial purposes. This method is ideal for large scale production and is widely used for manufacturing coins, pendants, earrings and shanks. On a smaller scale it can be taken up individually and with the help of stamps, hammer and other tools.

STAMPING

ADVANTAGES:
  • Cost of production is low.
  • It gives consistent quality and uniformity.
  • Pieces produced require less cleaning and finishing.

DISADVANTAGES:
  • In this process design options are limited.
  • It is not suitable for stone setting.
In-depth knowledge of methods of production always yields good results. It gives one the confidence to design jewelry as it makes one aware of the practical aspects of production. 

 To have a clearer understanding of the processes one must visit a factory site.





*The Author is a Colored Stone Graduate from Gemological Institute of America, Mumbai and a Diamond Graduate from Solitaire Diamond Institute, Bangalore. She also holds a Diploma in Jewelry Designing & Manufacturing from Jewelry Product Development Centre, Jaipur. She also blogs at 'The Jewel Affair'

*Picture Courtesy: Google Images