Technical Guide ·
Blister-grade aqueous varnish is not a general gloss tin
A card that looks glossy can still let the blister film go. Grade 819 is the catalog line for that seal. 818D and 820 are other jobs.
The film has to seal to the coat you chose
A blister card fails when the plastic lets go of the printed board, not when the carton merely looks dull. General gloss, a high-rub gloss, and a blister grade are sorted apart in the LOCOER aqueous table. 819 is the blister label. 818D is ultra-gloss high-rub. 820 is an aqueous UV primer. Running one drum for all three is how seals open in the warehouse.
Honglu water-based varnish is quoted for gloss or matte on folding carton and commercial sheets. It is not the stand-in for 819. If the job is a blister, say blister on the RFQ.
- Name the film: the polymer and the thickness, not only “blister”.
- Name the board and whether the seal area is ink, varnish, or both.
- Do not replace 819 with 818D because the lid looks shinier.
- Do not replace 819 with 820 because both sit near the end of the table.
- Powder and a wet film block a seal the same way they block foil.
What to trial
Seal on the live machine, with the live film and the live mold, over the ink you will actually print. A hand press in the office is a screen, not the record. Keep a card that holds and a card that opens, with grade and batch written on them.
Coat weight and dryer settings belong on that card. A heavier film can look tougher and still release. The mottle and rub article covers starved or flooded coats. This note is only the grade boundary.
Ink under the seal
A heavy conventional ink that is still soft, or a UV ink that is under-cured, changes the surface 819 has to grip. Tell us which ink is down before we name the varnish. We will not blame the blister grade for a lamp or a pile that was never dry.
What HuiRun will quote
When the finishing step is blister, we quote 819 from the authorized table, or we say we cannot match it if the film and the coater are outside what that TDS describes. The reply includes whether the kilos are Hefei stock or a factory slot. It does not include a peel force.
What the quote covers
HuiRun does not run blister machines and does not sign a seal strength. “Blister” on a catalog row means that is the grade to trial, not that every film and every mold will pass.
Key questions
- What is the short answer?
- A card that looks glossy can still let the blister film go. Grade 819 is the catalog line for that seal. 818D and 820 are other jobs.
- The film has to seal to the coat you chose
- A blister card fails when the plastic lets go of the printed board, not when the carton merely looks dull. General gloss, a high-rub gloss, and a blister grade are sorted apart in the LOCOER aqueous table. 819 is the blister label. 818D is ultra-gloss high-rub. 820 is an aqueous UV primer. Running one drum for all three is how seals open in the warehouse.
- How should the numbers in this article be used?
- The ranges here are typical shop practice. Confirm them on your press, paper lot, and lamps or dryer. Catalog numbers stay on the data sheet; the signed sheet comes from a trial.
The ranges here are typical shop practice. Confirm them on your press, paper lot, and lamps or dryer. Catalog numbers stay on the data sheet; the signed sheet comes from a trial.
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