Production of tinplate is  a complex high-tech process that requires specialized metallurgical equipment.

Rolling of the hot rolled steel strip to a final thickness 0,11-0,5mm occurs on reversible cold rolling mills wherein its thickness is reduced to 90%. Each cage is comprised of four rolls arranged one above the other. Two working rolls (each having a diameter of about 600 mm) are  in direct contact with the strip during rolling. While the supporting rolls supports, the working rolls provide the necessary rigidity of the system. During cold rolling the strip thickness is reduced on more than 90%. In this step, a single plate rolled steel sheet unlike double rolling are rolled to almost final thickness.

The technological process of rolling, control over presented parameters and the state of the equipment are carried out automatically. All information is transmitted to the control station monitors. If necessary, there is the possibility of manual substitution.

The purpose of the electrolytic cleaning is to remove from cold-rolled strip all traces of oil and metallic dust, before the heat treatment in bell furnaces. During cold rolling the cold-rolled strip is processed with the lubricating oil and cooling emulsion. Before annealing, all traces of oil and emulsions must be removed from the strip, since their residues can prevent creation of  quality covering with tin. Purification is carried out during electrolytic degreasing process in which electric current is applied to the strip during its passage through the alkaline bath, and then goes brushing, rinsing in water and drying.

After annealing at a temperature of 600-800 ° C the hardness of steel decreases, and the ductility is reduced to the desired level. For annealing of tinplate two types of annealing can be used: annealing in bell furnaces or continuous annealing.

During the annealing the air in furnaces is replaced by oxygen-free protective atmosphere in order to prevent oxidation of the steel. Indirect heating of coils is carried out with using natural gas. Annealing takes place at temperatures of 600-800 ° C.

The rolls are heated to a temperature of exposure, which depends on the steel grade, the same applies to the exposure time. After annealing, the furnace cover is removed and the steel is left to cool in a controlled manner. The crystal structure, which becomes elongated in the process cold rolling, becomes coarse again.

The thinner and more durable tinplate is made, the more effective the usage of the material in the manufacture of tin cans is carried out. These properties of tinplate are achieved in the result of such  technological operations as tempering and double rolling.

Tempering is cold rolling with small crimping significantly reduces the tendency of the annealed metal to inhomogeneous deformation, which manifests itself in the form of various types of defects in subsequent process steps (stamping housings bipartite cans, manufacturing all cans).

After the first cold rolling and annealing, instead of tempering, the steel strip may be subjected to a second cold rolling with lubricant, the thickness is reduced by 10-50%. In this way tinplate with  thickness 0,12-0,2 mm is made.

At this stage the plate is transformed into tinplate. For electrolytic tin coating the rolls of plate is welded between  and falls into an electroplating line in the form of a continuous tape. After a thorough cleaning, that includes alkaline electrolytic etching and rinsing in water, strip enters the electrolyte – an aqueous solution of a tin and salt. In the coating process the strip passes through the tin conductive rolls which are used as the cathode.

Tin bars, suspended on each side of the tape, acted as anodes. Under the influence of electric current the tin from anode goes into the electrolyte solution, and then is deposited onto the tape. Application of an electric current of varying strengths on each side of the bath permits to obtain coatings with different thickness on the sides of the strip (differentiated coating). As a part of many of the lines stretching machines are used  which largely eliminates the flatness of tin.

Tin plating has a whitish hue with a slight metallic luster, so in most cases, in order to create a bright mirror tin coating, surface of the plate is reflowed with  induction or contact electroheating with the temperature above the melting point of tin (232 C).

Usually electrolytic tinplate surface is exposed to chemical or electrochemical passivation. The main purpose of passivation is to stabilize the surface, that helps to stop the  growth tin oxide on the surface. The strip is  exposed to passivation on electrolytic tinning line after the reflow of surface of plate and grease before it. The process consists of passing  the strip through an aqueous chemical solution with usage of the electric current in most cases (electrochemical passivation).

In the line tinplate is cut into sheets measuring length with subsequent sorting, stacking and packing. Packaging of the rolls is implemented in manual mode.

Raw material

Used raw materials:

  • pickled hot-rolled sheets;
  • tin
  • auxiliary materials

As raw materials for the production  billets that has passed hot-roll are used. The choice of material for the production of cold-rolled steel will depend on the conditions in which it will be operated.

Electrolytic tinning tinplate is made of steel 08kp, 08ps, 08U with the chemical composition according to GOST 1050-88, the thickness of 0.12 – 0.5 mm, width 600-1250mm in sheets or rolls, weighing up to 25 tons according to GOST R 52204-2004 and EN 10202-2001.

Comparative table of marks of sheet according to GOST and EN

Purchased rolled sheets parameters are defined by requirements to feedstock for tinplate production, namely:

  • Type of the used steel: low-carbon steel.
  • International grades of the used steel: EDDQ, DDQ, DQ, CQ.
  • Thickness: 1.6 mm- 4.0 mm.
  • Width: 600 – 1 300 mm.
  • Russian standards for steel: 08кп, 08пс,08ю, with chemistry according to GOST ГОСТ 1050-88

Purchased tin parameters are defined by requirements to feedstock for tinplate production. According to GOST 860-75, quality of tin, used in tinplate production, must meet requirements as follows:

Premium tin:

  • 01пч (with minimum Sn content 99.915%).
  • 01 (with minimum Sn content 99.9%).


The main partners in the project are the following companies:

SMS Group GmbH is  a group of companies with global oriented operations in the field of production of machinery and equipment for the steel and non-ferrous working plants. The range of products comprises steel making and rolling mill machinery, as well as pipe and shaped steel production equipment, press-forging plants, induction furnaces. SMS Group GmbH had started its activity in 1871.

SMS Group GmbH is  a group of companies with global oriented operations in the field of production of machinery and equipment for the steel and non-ferrous working plants. The range of products comprises steel making and rolling mill machinery, as well as pipe and shaped steel production equipment, press-forging plants, induction furnaces. SMS Group GmbH had started its activity in 1871.

Headquarters of the company is located in Germany, technical agencies and production centers are found in Sweden, Belgium, Spain, Russia, Romania, the USA, Canada, Brazil, the Republic of South Africa, China, India, Thailand.

SMS Group GmbH renders services associated with the equipment engineering design, development, construction design, installation, setup, the plant automation and the personnel training. For existing production lines, SMS Group GmbH offer services for expansion and modernization of the production process equipment.

SMS Group GmbH supplies complete metal working complexes on a turnkey basis, or individual machines and devices/units to outfit steel, aluminium and non-ferrous production process lines.

Production program:

  • Metal spraying/plating installations.
  • Steel melting shops, secondary processing.
  • Continuous casting machines.
  • Hot rolling mills.
  • Cold rolling mills.
  • Strip processing machines.
  • Electric equipment and automation systems.

Group of companies «MetProm» is one of the major engineering companies of metallurgical sector in Russia, founded in 1992 and dynamically developing the trend of realization of projects on «turn-key» basis, starting from consulting and preliminary engineering up to putting the projects into operation.

Depending on the stage of realization, the company renders the following services:

  • comprehensive implementation of projects on “turn-key” basis;
  • technical consulting;
  • preliminary engineering (substantiation of investments. main engineering solutions, feasibility study);
  • engineering survey;
  • design and working documentation;
  • passing examination of project documentation;
  • supply of main and auxiliary equipment;
  • construction and erection works;
  • design and building supervision;
  • equipment supervision and commissioning works.

Engineering company «MetProm» offers to their clients: investment projects’ management on EPCM model basis (Engineering – Procurement and supply of equipment – Construction – Management of project) in the field of ferrous metallurgy, including all the production practices.

GC «MetProm» has an extensive experience in modernization and reconstruction of metallurgical projects; improving their capacity, introduction of the new state-of-the-art technologies, including those saving resources and ecologically mostly safe.