The company was incorporated on 30th day of June 1959 as a private limited company with object
sector in the memorandum of association which inter alia provided for establishment and operation of a glass sheet factory.With view to associate a larger section of the public with a growing industry the company was converted into a public limited company on 27th October 1962. After liberation of Bangladesh the Govt. of the peoples republic of Bangladesh placed Usmania under the control & management of the Bangladesh chemical industries corporation according to relevant provision of the Bangladesh enterprises order, 1972.
Chemically glass is defined as a mixture of non volatile inorganic oxides resulting form the decomposition and fusing of alkali and alkaline earth compounds sand and other glass constituents ending in a products with random atomic structure .
COMPOSITION OF GLASS
The principal raw materials used for manufacture of sheet glass are silica sand, soda ash, dolomite, limestone, sodium sulfate and coal.The main raw material sand silica is available at chaudogram of comilla and sylhet in our country and dolomite from China, coal from India and other raw materials are imported from foreign countries.
PROCESS OF MANUFACTURE
All raw materials used for glass making e.g. silica, soda ash, limestone dolomite sodium sulfate coal and cobalt oxide are individually weighted according to specified ratio of consumption. The batch is than introduced to a rotating batch mixture to get a homogeneous batch. The thoroughly mixed batch id then stacked from where the batches are sent to the melting tank of the furnaces.The mixed batch stored in batch section is fed into furnace at an interval of half an hour with the help of trolly bucket at a rate of 0.34MT Per feeds. We are intending to convert this manual feeding process into automatic electromechanical process during BMRE of furnace-2.The main furnace has got mainly three zones viz. melting zone Refining zone and working zone .THR molten and refined mass is led to an auxiliary chamber known as drawing chamber through an arrow passage known as “THROAT” . Melting zone is required to be maintained at an approximate temperature of 1400OC to 1500 OC at which range batch material are melted into molten glass. The molten mass is then refined mainly through settling and the to proceed towards during chamber through working zone. The temperature at temperature ranges from 950 OC
&1200 OC respectively. In drawing temperature ranges 950 OC to 1050 OC. Abridge channel divides unto the furnace into two main parts. The molten mass after entering into the drawing chamber gradually approaches a floating bridge installed prior to the debit use is maintained in the debit use where the sheet in the process of forming is gradually cooled by sheet steel coolers on both side of sheet by supplying water through 2 inch Dia. Pipe, the glass is drown to sheet through the vertical Fourcault machine temperature is control are the three stage a in order to make the sheet glass cool and hard, In the vertical fourcault machine there are 15 pairs of rollers to draw sheet glass each roller rolling in opposite direction to help drawings . At the initial pair of rollers temperature is maintained at 500 o C at fourth pair it is maintained at 300 OC and at 14th pair it is maintained at 180oC. When the sheet glass passes the last pair of rollers and reaches at the breaking point the temperature is about 80 OC The drawing machine is regulated by a speed regulated to produce sheet of different thickness, Higher the speed thinner the lesser the speed thicker the glass .The fourcault machine is fitted with an automatic cutter to cut the drawn glass
when it is reaches a desired height motorized according to the expected size of the glass sheet. Cut sheets are the stacked on trolleys and then sent to cutting hall Via Cargo lift for cutting into marketable sizes.
PRESENT PRODUCTION RATE
Usmania pens and operates its factory at kalurghat industrial area. Chittagong on a plot of land measuring 9.8 acres having capacity of producing ten million square feet of glass sheet from 2 mm on basis of thickness.
Company was able to sell 225.78 Lac sheets of glass sheets during the year under review which
is 112.33% pf the target of 201 LAC SFT, And 13% higher than the last year`s sales of 194.52
LAC. SFT. As a result the finished goods inventory of glass sheets of 9.04 lac sheets as on
30.6.2000 come down to 2.26 lac a special effort for increasing sales by expanding its market. By
distribution of UGSFL’ S glass sheets in different places to the country with the help of the dealers
of Usmania Glass Sheet Factory, it had been possible to capture new markets. Moreover,
consequent upon timely steps are taken by the management. NBR maintained 30% supplementary
duty on all categories of imported glass sheets of which, it has been possible to keep the market
of glass sheets under control review. During first 3 months if the current year 2000-2001, 51.89
lacs sheets of glass sheets has been sold this is 102.43% of proportionate target.
The produced glass is not so much transparent because of the presence of unexpected amount of
Fe with raw materials.
Strict safety codes and regulations are followed in this factory. All modern and sophisticated
safety equipments have been procured and are in used. Fire fighting equipments are always ready
to give their services as and when required.
The factory maintains laboratory to analysis and test raw materials and finished products.
The exhaust gas (CO2 CO & SO2) from the furnace is vented to the atmosphere. The gas is
removed above 120 ft. from the top of the furnace. But small volume of these gases may causes
danger for surrounding atmosphere.