Introduction

In our manufacturing unit at Khunti (Ranchi) we incorporate the latest technological developments and are constantly modifying and updating on processes to meet customer's particular requirement.

Lac is the resinous secretion of a microscopic tiny insect, popularly known as Laccifer Lacca. The lac insects belongs to the family of a scale insect and mealy bugs of the super family "coccoidea". On an average three hundred thousand insects produce one kilogram of lac resin. Sticklac is the basic raw material.

Sticklac is converted to commercial grades of seedlac and shellac. The yield(40%-60%) depends on various factors like host trees, area of cultivation, etc.

 
 

Seedlac

Sticklac is first crushed and sieved to remove sand and dust. It is then washed in large vats again and again and at the same time rubbing the lac against the sides of the Vat to break open the insect bodies and dissolving the colouring matter in water.

The lac thus cleaned is spread on large, clean, open air floor to dry. After drying, it is winnowed and sieved to get the commercial variety of Seedlac. Seedlac is mostly used for conversion into Bleached Shellac and different types of Shellac.

Grades of Seedlac :

 

 


 

 
 

Grades of Shellac

 
 
Hand Made Shellac

Seedlac is filled into a long, narrow cloth bag. One end of the bag is held in front of the charcoal oven while the other end attached to a windlass is gradually turned. The molten lac is scraped out and mixed thoroughly to ensure uniformity and transferred to a block of molten lac on the surface of a smooth porcelain cylinder filled with hot water.

Standing in front of fire, the workman so manipulates the sheet as to heat it uniformly and then streches it with his hands, legs and mouth. It is pulled in all directions to produce a sheet of about 5'x4' with a varying thickness from 1/16" at edges to about 1/1000 of an inch in the center.

Grades of Hand Made Shellac

 

Machine Made Shellac

Machine Made Shellac is produced in two different ways-Heat process and Solvent process.

Heat Process

Separation of pure lac is achieved by melting seedlac by steam heat and squeezing the soft molten lac through filter by means of hydraulic presses. The molten lac is then stretched by means of rollers into long and continuous sheets which is broken into pieces to form small flakes.

Grades of heat process Shellac (Machine made)

Solvent Process

The separation of insoluble impurities is achieved by dissolving the lac in a suitable solvent, usually industrial alcohol. The solution is then filtered through fine cloth and the alcohol is recovered by boiling the solution. The shellac is then stretched to the required thickness on a roller. The solvent process lends itself to manufacture different types of shellac containing varying percentage of shellac wax. Dewaxed or partly Dewaxed shellac may be manufactured by this process. The wax content may be as low as 0.2%.

Grades of Dewaxed Shellac

Bleached Shellac

The basic procedure in the production of bleached shellac consists of dissolving seedlac in aqueous sodium carbonate solution at 90-100 degree celcius. This solution is then treated with sodium hydrochloride, cooled and filtered. The bleached shellac is reclaimed from the filtered solution with sulphuric acid. The precipitated bleached shellac is then filtered and washed with water for removal of acid and dried.

Bleached shellac is manufactured / exported in following two grades :

Aleuritic Acid

Aleuritic Acid (9, 10, 16-trihydroxypalmitic acid), obtained from shellac by saponification, is a unique acid containing three hydroxyl groups of which two are of adjacent carbon atoms.

Aleuritic Acid is moderately soluble in hot water and crystallises out on cooling the solution. It is soluble in the lower alcohols such as methyl, ethyl and isopropyl alcohols.

Techinal grade Aleuritic Acid (purity 99%) a slight yellow and almost odourless solid, is now manufactured by us. There is a continuous growing demand of aleuritic acid in the fields of perfumery and pharmaceuticals due to it being an excellent starting material for the synthesis of civetone, ambrettolide, isoambrettolide etc, which have the musk like odour......Click here for the technical details


Shellac Wax

4-6 % of the wax is only contained in crude Shellac and it is obtained as waste product during the manufacturing of solvent process of shellac.

The commercial qualities are hard, brown and have excellent shine-producing charac-teristics which can nearly be compared with those of Carnauba Wax.

Shellac Wax is mainly a mixture of esters (approx. 60 %) and free alcohol (approx. 35 %). Furthermore, small amounts of hydrocarbons, penta- and hentriacontanes and approx. 1 % laccic acid are contained.

Polishes which normally consist only of paraffin and montan wax, give a highly shining surface if only a small amount of Shellac Wax is added; moreover as substitute for Candelilla Wax.......Click here for the technical details


Storage

The Shellac produced is normally allowed to cool off after stretching for a few hours and then transferred to a cool-shedded godown. It is best stored in air-conditioned ware-houses which maintains a temperature between 14-18 degree centigrade. Storage under such conditions maintains the quality of Lac although its main function is to prevent Shellac from blocking in the hot weather which is encountered for most of the year in India.



 
 
Other Products

The other agri products which we export is :

 

 

Crushing of sticklac

Washing of sticklac

Drying of Seedlac

 

 
 
 
 
 
 
 
 
 
 


 
 
 
 
 
 
 
 
 
 
 
 
 

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