Tinplate is a thin steel sheet coated by tin. It has an extremely beautiful
metallic luster as well as excellent properties in corrosion
resistance, solderability, and weldability. Tinplate is used for
making all types of containers such as food cans, beverage cans, 18-liter cans, and artistic cans. Its applications are not limited to containers; recently, tinplate has also been used for making electrical machinery parts and many
other products.
By far the largest application of tinplate is in packaging and it
is ideally suited for this purpose, by virtue of it being
non-toxic, light in weight, strong, corrosion resistant and easily
formed, soldered and welded; it also provides an excellent printing
surface. The tin coating has a low melting point, possesses
lubricant qualities and imparts a good appearance. Cans made from
tinplate are easy to handle, dispose and store. Tinplate is
primarily used for packaging foodstuffs and beverages, but it is
also used in containers for oils, grease, paints, powdered,
polishes, waxes, chemicals and many other products. Aerosol
containers and caps and closures are also made from tinplate.
Tinplate is composed of several layers:
1. Steel Substrate: The core of tinplate is low-carbon steel,
providing the necessary strength and durability.
2. Tin Coating: The steel sheet is coated with a thin layer of tin,
which is applied through an electrolytic process. The thickness of
the tin layer can vary based on the application, and it protects
the steel from corrosion and gives a glossy finish.
3. Passivation Layer: After tinning, a passivation treatment
(chromate coating) is often applied to enhance corrosion resistance
and promote adhesion for further coatings, such as lacquers or
paints.
4. Oil Coating (Optional): In some cases, a thin oil layer is
applied to protect the tinplate from scratches and oxidation during
storage and handling.
Applications of Different Types of Tinplate
1. Food and Beverage Packaging:
- The most common use for tinplate is in the packaging industry,
particularly for food cans (e.g., fruits, vegetables, soups) and
beverage cans (e.g., sodas, beer). The tin layer prevents the steel
from corroding, and the non-reactive surface keeps the food fresh.
2. Aerosol Cans:
- Aerosol containers for products like deodorants, hairsprays, and
air fresheners use tinplate because it offers good corrosion
resistance and strength to withstand internal pressure.
3. General Line Containers:
- Paint cans, oil containers, and other general-use packaging often
use tinplate or TFS to protect the contents from environmental
exposure while providing a durable exterior.
4. Bottle Caps and Closures:
- Tinplate is commonly used for crown caps, twist-off caps, and
screw caps for bottles because of its formability and corrosion
resistance.
5. Decorative Packaging:
- Tinplate is also used for premium decorative packaging like
cookie tins, tea containers, and gift boxes due to its strength,
aesthetic qualities, and ability to be printed or embossed easily.
