Converter diagnostic / film adhesion
Water-based ink adhesion on film is a compatibility result, not a property of the ink alone. Film chemistry, print side, treatment age and uniformity, surface contamination, ink selection, transferred film, drying, overprints, and later converting steps all affect the observed result.
Start with the symptom
Begin by identifying the exact film and the exact failure. Ink lifting in a tape check, scratching after printing, color-to-color separation, loss after lamination, and damage after heat or packing are different observations. A test result is useful only when the sample conditioning, test method, printed side, and time after printing are recorded.
The print detaches from the film or transfers to tape. Record the tape, application method, dwell, pull direction, time after printing, and whether failure occurs at the film-to-ink interface or between printed layers.
The surface is damaged by handling even though a simple tape check may appear acceptable. Distinguish true loss of adhesion from an ink film that is still soft, insufficiently dried, or not designed for the required abrasion exposure.
Edges, lanes, or different positions behave differently. Treatment uniformity, contamination, film gauge or additive variation, dryer distribution, and impression or transfer variation should be mapped.
Printing passes an initial check, then fails after rewinding, aging, lamination, heat, sealing, filling, or contact with another layer. The full print structure and process exposure must be part of the evaluation.
Possible causes
| Problem | Possible direction | What we need from you | Trial note |
|---|---|---|---|
| Film identity and print side | Confirm polymer family, grade, coating or additive package, treated side, age, storage, and whether the roll was printed on the intended surface. Similar-looking films are not interchangeable evidence. | Supplier data, roll and batch identification, unprinted film, marked print side, storage history, and a known acceptable film if available. | Do not generalize a result from one film grade to all PE, PP, PET, or other film structures. |
| Surface treatment and cleanliness | Review treatment immediately before printing using the converter's controlled method, together with treatment uniformity, aging, handling, slip or bloom, dust, oil, and other contamination. | Treatment equipment status, onsite test records, time from treatment to print, surface map if available, and information on handling or contamination. | A nominal supplier value or old treatment record does not confirm the surface presented to the press today. |
| Ink system and intercoat compatibility | Confirm that the ink direction is intended for the film and print structure. Review white and color sequence, mixed ink systems, primer or varnish, rework additions, and whether a later color re-wets the first layer. | Product names and batches, color sequence, primer or varnish details, rework history, and samples showing which interface fails. | Film-to-ink adhesion and color-to-color adhesion should be evaluated separately. |
| Drying and transferred film | Check residual moisture, dryer and exhaust condition, line speed, transfer volume, solid coverage, overprint build, and whether the print cooled before winding or testing. | Press speed, drying path, transfer equipment, image coverage, print sequence, time to rewind, and time before adhesion evaluation. | A soft or incompletely dried film can look like adhesion failure; repeat the same test after controlled conditioning. |
| Test and downstream requirement | Define the actual approval test and later exposure. Tape, scratch, rub, lamination, sealing, heat, chemicals, filling, and package handling do not measure the same performance. | Written test method, conditioning time, acceptance reference, downstream materials and process, end-use description, and failed converted samples. | Approve against the real requirement; passing one informal test does not confirm the complete package structure. |
First checks
First-pass review
Information to provide
Send unprinted and printed film from the same roll, marked print side, grade and batch information, treatment and storage history, and an acceptable reference if one exists.
Provide ink products, color and white sequence, primer or varnish, surface or reverse print, transfer details, dryer setup, speed, and time to winding.
Show affected web positions, colors and interfaces. Include the written test, conditioning interval, tape or device, and labeled photos of the result.
Describe lamination, coating, sealing, heat, filling, packing, or other exposure, along with the stage and elapsed time when adhesion changes.
Controlled trial path
Trial sequence
Related routes
FAQ
Film grade, batch, print side, treatment uniformity and age, surface additives, storage, contamination, transfer, drying, and test timing may differ. Compare labeled rolls under the same print and test condition before assigning the cause to ink.
No. Treatment is one input. The exact film surface, treatment condition at printing, cleanliness, ink compatibility, film weight, drying, print structure, conditioning, and downstream use still need confirmation.
Provide exact film and print-side samples, supplier and batch details, treatment records, print structure, ink products, transfer and drying condition, standardized test results, and the later process where failure appears.
Share the substrate, print process, ink or varnish identification, press condition, labeled failure samples, test method, and downstream requirement. JLJ Coating can review the evidence and discuss a controlled trial direction.
