The Gold Standard of Food Preservation

Technical Whitepaper: Tinplate (ETP) Specification

Tinplate, technically known as Electrolytic Tinplate (ETP), is a low-carbon steel sheet coated on both sides with a fine layer of commercially pure tin. At Golden Soar, we source prime-grade ETP compliant with ASTM A623 standards.

1. The Chemistry of Protection

The tin coating acts as a sacrificial anode in some environments but primarily as a physical barrier. However, for acidic foods (like tomato sauce or fruits), tin can dissolve. This is why Internal Lacquering is non-negotiable. We utilize:

• Gold Epoxy Phenolic: The industry standard for acidic and sulfur-containing foods (fish, meat). It offers excellent adhesion and flexibility.
• White Polyester (BPA-Ni): Developed for the infant formula market. It contains zero Bisphenol-A, meeting the strictest EU regulations.
• Aluminized Spray: Used on the weld seam to restore protection where the tin layer was melted during welding.

2. Temper and Hardness (DR vs. SR)

We offer two main grades of steel temper:

• Single Reduced (SR): Softer, more ductile. Ideal for cans that require beading (ribbing) or deep drawing (2-piece cans).
• Double Reduced (DR): Stiffer and thinner. It allows for “lightweighting” (cost reduction) but is less ductile. Used for standard beverage or food can bodies.

3. Lithography: Metal Decorating

Unlike plastic which is often screen printed, metal requires offset lithography. We print on flat metal sheets before they are cut and formed into cans. This allows for incredibly high-resolution images (CMYK) and special effects like “Crackelure” varnish or matte/gloss contrasts. The ink is cured in a wicket oven at 180°C, ensuring it withstands the sterilization retort process later.