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Tinplate oil coating sounds trivial—a light film on top of the tin. Yet, the wrong oil type or weight causes lacquer failure, print rub-off, or rust in storage. Can makers specify two oil types for a reason: one for lacquer-ready stock, another for print-ready stock. Here is how the choice works.

Two Oil Types, Two Purposes

Oil type	Weight	Purpose
Palm oil (food-grade)	5–15 mg/m²	Food-contact cans, lacquer-ready
DOS oil (dioctyl sebacate)	2–5 mg/m²	Print-ready, temporary protection

Palm oil is edible and thin. Consequently, it remains on food-contact cans without affecting flavor. DOS oil is a synthetic ester designed for lubrication during stamping; it evaporates or washes off before lacquering.

Why Oil Weight Matters

Too little oil and the coil rusts or develops fingerprints. Too much oil and lacquer or ink will not adhere. Typical weights:

• Lacquer-ready: 8–12 mg/m² palm oil. Enough to prevent rust, but light enough to lacquer over.
• Print-ready: 2–5 mg/m² DOS. Minimal oil so ink bonds cleanly.
• Temporary storage: 15–20 mg/m² for long ocean transit.

If your stamping line expects dry stock, specify the lightest oil available.

What the Oil Actually Does

The oil layer serves three functions:

1. Prevents fingerprints during handling—oil spreads and hides skin oils.
2. Prevents rust by blocking moisture from reaching the tin surface.
3. Lubricates during stamping and forming—reduces die wear.

However, oil is not a corrosion treatment. It is a temporary barrier. Store coils dry and use them within 6–12 months.

Cold Rolling Sets the Surface Before Oil

Oil coats the top; cold rolling sets the surface underneath. The final cold pass produces the smooth, uniform surface that oil spreads evenly over. If cold rolling leaves roll marks or roughness, oil will not hide them. Furthermore, rough surface holds more oil in valleys, causing uneven coating.

Related Surface-Treated Products We Supply

Oil coating logic applies beyond tinplate:

• C11000 / T2 Copper Plate ships with a thin protective oil film to prevent tarnishing during storage.
• C12200 / TP2 Copper Tube receives inner-wall cleaning and end caps to keep moisture out during transit.

Specify the Oil in Your PO

A complete tinplate order reads: “T3, 0.20 mm, 2.8/2.8 g/m², palm oil 10 mg/m², lacquer-ready.” Leave out the oil specification and the mill applies its default weight, which may not match your lacquer or print process.

Get the Right Tinplate Oil

Tell us your can type and whether you will lacquer or print. We will confirm the oil grade and quote coil or sheet with a mill certificate.

• Email: vera.liang@ztwysteel.com
• Location: Xishan District, Wuxi, Jiangsu, China
• Supply range: tinplate substrates, copper plate/tube, nickel alloys
• Documentation: MTC with coating weight, oil type, oil weight, and dimensions

We reply within one working day.