Tinplate
The most frequently used form of packaging for canned fishery products is tinplate which is fabricated into two and three piece cans of a wide steel,onto each surface of which is electrolytically deposited a layer of tin. Base plate gauge varies,depending on the size of the cans which are to be manufactured and their intended application; however,it is usually between 0.15 and 0.30mm thick.Nowadays, for the manufacture of extra light gauge plate,steel sheet is cold rolled twice prior to being tin coated, and in these cases is referred to as double reduced(DR) plate. Tin coating mass varies,according to end use and whether or not lacquers are to be applied; the thickness of the tin coating layers ranges from around 0.4 to 2.5micron. Shown in Table 4 is the Designation, nominal coating mass and minimum average coating mass for electrolytically coated tin plate. Plate on which the tin coating mass is the same on each surface is known as equally coated plate; whereas plate with