Pickling is used to remove the scales adhering to the hot rolled coils.
Cold Rolling Mill Process
The pickled coil is fed into the cold rolling mill. Depending on the input thickness, desired output gauge and pass schedule is designed. The coil strip is run reverse and forward through the CR mill, with the thickness being reduced in each pass. Desired Thickness is achieved at the end of schedule. Resulting product is Full hard coil. CRFH is used for corrugated roofing sheet and some white goods.
Electrolytic Cleaning (ECL) Process
Electrolytic Cleaning Line is used to remove cooling oil mixed with water in an emulsion. Cooling oil is used in CR Mill to keep the temperature of the roll and the strip within limits. This gives degreased coils.
Batch annealing process is done to relieve the stresses that are built into the coil during the process of cold rolling CR makes coil hard and brittle. Annealing follows a heating - soaking - cooling cycle with cut off temperatures and times depending on the hardness required. After annealing the coil becomes soft.
Temper Mill (DCR/SR) Process
Annealed coil surface has to be given the proper finish and hardness. In most cases first skin pass is given than Temper mill is used to control the hardness, shape and surface finish. In few cases Double cold reduction process is used.
Rewinding line is used to trim the coil to required width. While rewinding the edge guide system ensures that the two sides of the coil winding is without any projected edges.
Electrolytic Tinplating Line
In ETL Tin coating is applied to both sides of the Tin mill black plate (TMBP) coil through an electrolytic process. Coil passes through various stages to remove any remnant traces of oil or emulsion, any oxide that may have formed in the CRM. Than tin coating on both the side of coil takes place at plating section. Thereafter it passes into the melting furnace where the deposited tin is melted to give it a brighter finish. After this the strip is chemically treated to reduce the action of atmosphere on tin and then coated with oil.
Cut to Length Line (CLL) Process
Tinplate coil is cut to the required length to prepare Sheets. All sheets are stacked as specified to make the packets.
Roll Grinding Shop
RGS is support service for the critical roll requirement of the CR Mills (6 Hi & 4HI).
Our packaging is designed considering environmental variations and transportation needs. It prevents transit damages and any seepage of water during transit to coils or sheets.
Each Coil or Packet is marked with Coil/Packet No, product grade, date, coating weight, thickness, hardness, finish, temper, net weight & gross weight, etc.