What is SPCC tinplate and how is it different from MR Type Tinplate?
SPCC tinplate is unique to China. It is Cold Rolled Feedstock not specialized Cold Rolled Coils (called Tinmill black plate in common parlance) which is used for tinning. The physical rolling of Cold rolled SPCC is either through reverse CR process or 5 / 6 stand mill This rolling is similar to the rolling which is done for TMBP. So the mechanical processes for pre-production is similar to to TMBP (tin mill black plate coils)
However it is the chemical properties of SPCC that differ from MR type. The Sulphur content is marginally higher as a percentage in SPCC. The chemistry parameters are tighter in HR for MR Type. Remember the chemistry starts from the Hot Rolled Coil feedstock and this chemical composition does not change with cold rolling.
SPCC tinplate is being used globally for General Line and non Food application without any mechanical difference in Container forming from the usual MR Type. There is about USD 20/- PMT price differential in price which in today’s competitive market becomes an important selling point. Price is lower for SPCC tinplate because of also higher availability of the feedstock.
SPCC tinplate is not recommended for food because of the likelihood of the marginally higher percentage of sulphur and other residual chemicals and its potential reaction with food particularly wet food. MR type tinplate is recommended for food.
So remember more than SPCC it is the equipment that the mills use and the quality controls for flatness, tolerance that matter in your final Can Making operation as long as you follow the rule of thumb for using SPCC for general line and MR Type for Food.
Source: The International Tin Association (formerly ITRI Ltd)