In flexible packaging printing and lamination, ink peeling and delamination often come down to wrong corona treatment. This guide compares non-corona, single-side corona and double-side corona BOPP film, covering dyne levels, use cases and production tips to help you select the correct grade and avoid costly rework.
What Is BOPP Corona Treatment?
BOPP (Biaxially Oriented Polypropylene) is non-polar. Untreated native surface is only around 31 dynes, and standard ink or adhesive cannot bond well.
Corona treatment uses high-voltage discharge to raise surface energy by creating micro texture and polar groups. ≥38 dynes is the minimum requirement for stable printing and lamination.
1. Non-Corona BOPP Film
Both sides remain untreated at ~31 dynes. ❌ Not suitable for printing, coating or lamination.
It features stable slip and consistent heat-sealing performance. ✅ Applications: heat-seal inner layer, packaging liner, release substrate, multi-layer core contact layer.
2. Single-Side Corona BOPP Film
One side treated to ≥38 dynes for printing and lamination; the reverse native side keeps good slip and heat seal. This is the most cost-effective mainstream grade.
✅ Applications: surface printing, label film, paper-plastic lamination, snack packaging, tape base film.
3. Double-Side Corona BOPP Film
Both sides reach high dyne levels, so either side supports printing, coating and lamination. Pick this grade when both sides need processing or orientation is hard to identify.
✅ Applications: double-sided printing, metallized BOPP, functional coating such as anti-fog coating. View our BOPP Anti-Fog Film for fresh produce packaging, which uses double corona for reliable coating adhesion. Note: It costs more and has weaker natural slip; custom slip additives are needed for heat-sealing needs.
Comparison Table
| Grade | Dyne Level | Printing & Coating | Main Applications |
|---|---|---|---|
| Non-corona BOPP | ~31 dynes, both untreated | No printing / coating | Heat-seal liner, release substrate |
| Single-side Corona BOPP | ≥38 dynes (treated side) | Only corona side works | Labels, tape base, single-side printing |
| Double-side Corona BOPP | ≥38 dynes, both sides | Both sides available | Anti-fog coating, double-sided print, metallization |
Practical Shop-Floor Tips
- Dyne decays over storage: Use corona-treated BOPP within 6 months; high temperature speeds up attenuation.
- Higher dyne is not better: Over-treatment makes film brittle. 38–40 dynes fits most printing jobs.
- Specify requirements on PO: Clarify single/double corona and whether treated surface is inside or outside the roll.
Summary
- One-side processing → single-side corona BOPP
- Dual-side processing / functional coating → double-side corona BOPP
- Only heat-seal liner, no printing → non-corona BOPP
Unclear corona specs often lead to delayed shipments and rework. Contact us if you need help selecting the proper BOPP film for your ink, adhesive and packaging structure.
