Coil coating paint

Back Coat for Coil Coating Applications

Back coat supports the reverse side of coated metal panels by providing backside protection, forming flexibility, system balance, and foam bonding discussion for sandwich panel applications.

  • Reverse-side protection
  • Forming flexibility
  • Foam bonding discussion
  • Backside stability
Coated metal surfaces and material handling

What back coat is built for

Back coat is built for reverse-side coating systems that require backside protection, forming flexibility, foam bonding discussion, and stable backside performance in complete coil coating structures.

Benefits

  • Reverse

    side protection — Provides practical protection for the non — exposed side of prepainted metal panels.

  • Built for forming

    Helps the back coat layer maintain integrity during bending, forming, and fabrication.

  • Foam bonding discussion

    Supports technical discussion for PU/PIR foam, rockwool, and sandwich panel systems.

  • System compatibility

    Works with primer, topcoat, substrate treatment, and curing process for balanced coating performance.

Typical applications

  • Construction panels

    Used on the reverse side of roofing sheets, wall panels, and other prepainted building materials requiring stable backside protection.

  • Sandwich panel systems

    Suitable for sandwich panel applications requiring reverse-side protection, forming flexibility, and foam bonding discussion.

    • PU/PIR foam panels
    • Rockwool panel systems
    • Cold storage panels
    • Warehouse panels
  • Appliance metal panels

    Provides practical backside protection for selected appliance metal panel coating systems.

Technical highlights

  • Backside protection

    Provides practical protection for the reverse side of coated metal panels.

  • Foam bonding discussion

    Supports technical discussion for PU/PIR foam, rockwool, and sandwich panel systems.

  • Flexibility

    Helps the coating layer tolerate bending and fabrication without losing integrity.

  • Backside scratch resistance

    Helps reduce backside surface damage during rewinding, transportation, and fabrication.

  • Compatibility

    Works with matching primer, topcoat, substrate treatment, and curing process.

  • Processing stability

    Supports stable application and backside coating control on the coil line.

Product Reference & Technical Support

Back Coat Product

Reverse-side coating path

Generic back coat path for coil coating systems requiring backside protection, forming flexibility, foam bonding discussion, and stable backside performance.

Key Performance Reference —HG/T 3830-2022Show

View key primer coating evaluation items based on HG/T 3830-2022 before requesting product documents.

Back coat evaluation usually focuses on backside protection, adhesion, flexibility, solvent rub resistance, reverse impact, T-bend performance, curing stability, and foam bonding discussion for sandwich panel systems.

ItemIndustry referenceTest method
Non-volatile content≥55%GB/T 1725-2007
Fineness≤20 μmGB/T 1724-2019
Pencil hardness≥2HGB/T 6739
Solvent rub resistance MEK times≥50GB/T 23989-2009
Reverse impact, kg·cm≥60GB/T 20624.2-2006
T-bend≤4TGB/T 30791-2014

The above values are general industry reference indicators for back coat systems. Actual performance, test results, and foam bonding references should be confirmed through product documents, TDS, internal test summaries, or project-based technical discussion.

Product Documents Available Upon RequestShow

Request product sheets, TDS, SDS/MSDS, COA, internal test summaries, foam bonding reference, or laboratory sample discussion.

DocumentAvailability
Product SheetRequest / controlled sharing
TDSRequest only
SDS / MSDSRequest only
COAAvailable by batch
Internal Test SummaryUpon request
Foam Bonding ReferenceTechnical discussion
Laboratory SampleSmall sample for initial evaluation

Need support evaluating back coat? Share your substrate, pretreatment condition, coating system, application, sandwich panel requirement, curing condition, and target performance with our technical team. Laboratory samples may be provided for initial evaluation.