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Introduction
In
our manufacturing units at Ranchi we incorporate the latest
technological developments and are constantly modifying and
updating on processes to meet customers 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. |
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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.
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CRUSHING
OF STICKLAC
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WASHING
OF STICKLAC
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DRYING
OF SEEDLAC
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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 :
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GRADES OF SHELLAC
•
Hand Made •
Machine Made
• Heat
Process
• Solvent
Process
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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 scratches it with his hands,
legs and mouth. It is pulled in all directions to produce
a sheet of about5'x4' with a varying thickness from 1/16"
at edges to about 1/1000 of an inch in the center.
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Grades of hand made Shellac
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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 the machine-made shellac under heat
process.
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Grades of heat process
Shellac (Machine made)
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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 molten
shellac is then stretched to the required thickness on a roller
followed by stretching machines. The solvent process lends
itself to manufacture of different type 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%.
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Grades of dewaxed Shellac
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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.
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Other Products
The other agri products which we export is :
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