High Definition Lithography Tinplate Coil T3 Temper For Beverage Can Body Printing

Print quality on a metal can is decided long before the press runs. It is decided by the roughness, flatness and surface energy of the tinplate sheet that the ink lands on. High definition lithography tinplate is milled specifically for that requirement. Work rolls polished to a fine finish transfer a controlled, uniform topography to the steel, and the resulting low roughness allows the lithographic blanket to make complete contact across the sheet instead of bridging the microscopic peaks that cause grain and mottle in halftone areas.

The substrate is a low carbon steel coil at 0.14mm to 0.22mm, annealed by the batch process to produce a uniform grain structure and then temper rolled to T2 or T3. Tin is electroplated at 2.8 g/m2 per side and the surface is passivated and lightly oiled to a consistent film weight. That combination gives printers a stable, predictable surface for four colour process work, spot colours, overprint varnish and internal lacquer, and gives can makers a material that still forms cleanly after the ink film has been cured.

• Extra Smooth Surface: Roughness is held in the 0.20 to 0.35 um band with a fine, uniform topography produced by polished work rolls, so the lithographic blanket makes full contact across the sheet and halftone dots reproduce without grain interference or mottling.
• Sharp Halftone Reproduction: The combination of low roughness and consistent flatness supports 175 lines per inch screening with clean dot gain, allowing photographic imagery, fine type and detailed brand marks to survive the offset press and the subsequent forming and necking operations.
• Stable Ink And Varnish Adhesion: Correctly passivated and lightly oiled surfaces give consistent surface energy, so inks, overprint varnishes and internal lacquers anchor uniformly and resist crazing when the printed sheet is later rolled, beaded and seamed.
• T3 Temper For Forming After Printing: T3 single reduced temper provides enough ductility for printed blanks to be body rolled and seamed without cracking the ink film at the bend, while remaining stiff enough for reliable sheet handling through the press.
• Width And Coil Build Matched To Presses: Coils are supplied from 660mm to 1050mm in width with tightly wound, edge aligned build and a choice of 420mm or 508mm inner diameter, so printing houses can load existing decoilers without adapter work.
• Consistent From Coil To Coil: Roll roughness, temper and coating weight are measured on every coil and recorded against the heat number, keeping press settings stable across repeat orders so that reprint runs match the original colour target.

The material is used for beverage can bodies and ends, decorative food cans, aerosol can bodies, crown caps and lug caps, and general line containers where printed graphics carry the brand. It is also specified for premium metal packaging such as confectionery tins, tea caddies and promotional boxes where photographic artwork and fine typography must reproduce accurately at small sizes.

Printing houses typically run the coil through a UV or conventional offset line and then cut, lacquer and ship sheets or printed coils to the can maker. Because roughness and temper are held within narrow limits, press operators do not need to re-profile settings between coils, and reprint runs reproduce the original colour target. Print trial coils with a certified roughness report are available so that a printer can validate dot gain and ink adhesion on its own press before committing to production volumes.

Each coil is wrapped in anti-corrosion VCI film, interleaved with desiccant bags, then sheathed in kraft paper and finally enclosed by galvanised steel sheet with reinforced corner protectors. Coils are stacked eye-to-sky or eye-to-wall according to customer unloading equipment, strapped with PET bands at four points, and loaded into 20ft or 40ft containers on fumigated wooden skids. Sheet bundles are protected by edge boards and plastic strapping so that the surface finish reaches the destination port free of scratches, white rust and transit dents.

The mill operates under an ISO 9001 certified quality system. Every heat number is traceable and each shipment is accompanied by a mill test certificate covering chemical composition, tensile and yield strength, tin coating weight measured by coulometric stripping, and surface roughness. Third-party inspection by SGS, BV or Intertek can be arranged on request before container sealing, and a retained sample from each lot is archived for twelve months for future claim investigation. Any dimensional or coating non-conformity is settled by replacement or price adjustment within the contracted tolerance framework.