GALVANISED IRON SHEETS
[EIRI/EDPR/1432] J.C. 211
INTRODUCTION
Galvanizing is dipping in molten bath of zinc for adhersive coating on ferrous metals. The clean & dry article is dipped in a bath of molten virgin spelter containing 98% zinc covered with sai-ammoniac, zinc melting at 420oC. The process required that the sheets are in a moderate state of cleanness i.e. that all excess oil & grease is removed and any oxide or scale which is not eliminated with light acid pickling must be removed by blasting or some other method.
On removal of the sheets from pickling tank after the required time, which will depend on the degree of corrosion scale or oxide which is present, the parts are whashed in cold running water.
It is vitally important that the sheets are thoroughly dried to remove all the last traces of moisture prior to entering the molten zinc.
As the galvanizing process is carried out at temp about 450oC, an moisture which enters the molten zinc will immediately be converted to steam with explosive results, which are highly dengerous as the molten zinc is ejected from the bath. The dried, fluxed sheets are gently lowered into the zinc bath with the operator positioned behind a protective barrier. The sheets are left in zinc bath for a specific time. If the sheets are removed before they reach with the temp of molten zinc, the zinc coating will be relatively thick and if these are left too long the bath, there will be tendency for the iron-zinc alloy.
Various additions can be made to the liquid zinc to improve adhesion & appearance. One of common additions is aluminium for brightness.
About the corrugation of sheets for defining them, these are thim plates of 18 to 26 S.W.G. rolled out in alternate equal curves/semicircular corrugations of elevation & depressions or ridges and valleys by which corrugation & the rigidity of the sheets is increased. The pitch, or the distance between the centers of alternate curves, varies from 3 inches to 5 inches. These sheets are principally used for light roofing purpose and for covering the sides of more less temporary structures.
COST ESTIMATION
Land & Building (Area 2500 sq.mt.) Rs. 1.42 Cr
Plant & Machinery Rs. 69 Lacs
W.C. for 2 Month Rs. 2.12 Cr
Total Capital Investment Rs.4.46 Cr.
Rate of Return 23%
Break Even Point 62%
CONTENT
INTRODUCTION
USES & APPLICATIONS
B.I.S. SPECIFICATIONS
MANUFACTURERS/SUPPLIERS OF G.I. SHEETS
PLANT LAYOUT
TECHNICAL SPECIFICATIONS FOR G.I. SHEETS
MANUFACTURING PROCESS
PROCESS OF MANUFACTURE
PICKLING
FLOW SHEET CHART
SUPPLIERS OF RAW MATERIALS
SUPPLIERS OF PLANT AND MACHINERIES
APPENDIX – A:
01. PLANT ECONOMICS
02. LAND & BUILDING
03. PLANT AND MACHINERY
04. OTHER FIXED ASSESTS
05. FIXED CAPITAL
06. RAW MATERIAL
07. SALARY AND WAGES
08. UTILITIES AND OVERHEADS
09. TOTAL WORKING CAPITAL
10. TOTAL CAPITAL INVESTMENT
11. COST OF PRODUCTION
12. TURN OVER/ANNUM
13. BREAK EVEN POINT
14. RESOURCES FOR FINANCE
15. INSTALMENT PAYABLE IN 5 YEARS
16. DEPRECIATION CHART FOR 5 YEARS
17. PROFIT ANALYSIS FOR 5 YEARS
18. PROJECTED BALANCE SHEET FOR (5 YEARS)