Label ink additives must fit the facestock, print process, drying or cure, rewinding and conversion sequence. A film-wetting defect, press-loop foam and dry-label blocking require different experiments. Lock substrate treatment, viscosity, ink deposit and drying first, then change one additive route at a time.
Screen the 2100 wetting grade after identity confirmation.
Screen 3062.
Gate 3501 by dose and protocol.
Define the complete label construction
Record paper or film facestock, topcoat, treatment, ink technology, overprint varnish, adhesive, liner and conversion route. Pressure-sensitive, shrink, in-mold and wet-glue labels do not share one acceptance protocol. Include die-cutting, matrix stripping, dispensing, seaming, shrinking or molding as applicable.
Resolve the 2100 product identity
Longchang has two distinct live records for a similar 2100 wetting grade: one titled CHLUMIAG® 2100 and one titled CHLUMIWE® 2100. The public site does not establish one unambiguous current brand identity. Require the exact commercial name, product code, TDS revision and COA before purchase or trial.
Compare the available routes
| Route | Published evidence | First experiment | Boundary |
|---|---|---|---|
| 2100 wetting grade | Two conflicting live identities; both pages state 0.1–1.0%, all three system types and flexible addition | Retraction, coverage and print laydown after exact identity confirmation | Do not assume which TDS or product data apply to the supplied lot |
| CHLUMIAF® 3062 | 100% active; printing-ink dose 0.1–0.5%; water/solvent/UV | Grinding, pumping, chamber or return-loop foam | Solvent dilution requires stability and defoaming tests |
| CHLUMIAG® 3501 | Printing inks, inkjet, overprint varnish and release/anti-sticking uses listed | Supplier-supported block or release study | No public recommended dosage, active content or quantified block/rub result |
Use the 2100 grade for measured film wetting
After confirming product identity, screen the supplier-approved dose only when ink beads, retracts or leaves irregular coverage on a verified facestock. Keep treatment, viscosity, anilox or screen, deposit and drying constant. Measure density, pinholes, line or dot quality, adhesion and overprint compatibility. Better spread does not prove stronger adhesion.
Measure corona or plasma treatment immediately before printing and again after realistic facestock storage. Treatment decay, topcoat variation and surface contamination can change wetting independently of the ink. Include at least two representative facestock lots before approving a dose for production.
Use 3062 for measured process air
Identify where air enters: dispersion, pump, chamber, return line or high-speed transfer. Screen within the documented 0.1–0.5% printing-ink range. Measure wet density, foam height and decay and cured pinholes. Reject a dose that lowers foam but creates craters, density loss, storage instability or poor rub.
Keep 3501 behind a block-test gate
First exclude retained water or solvent, inadequate UV dose, warm rewinding, excessive roll hardness and high storage temperature. Then request 3501’s current TDS, active content, starting dose and a reproducible pressure/temperature/time protocol. A public release application listing does not justify an invented equal-dose trial.
Use a controlled label matrix
| Trial | Change | Primary measure | Conversion gate |
|---|---|---|---|
| A | Unchanged control | Density, wetting, foam, drying and block baseline | Adhesion, rub and converting |
| B–D | Confirmed 2100 grade low/mid/high | Coverage, pinholes and print quality | Adhesion, OPV and lamination |
| E–G | 3062 within 0.1–0.5% | Wet density, foam and defects | Density, rub and storage |
| H–J | 3501 after data approval | Block at fixed pressure, heat and dwell | COF, rub, die-cut and dispensing |
Normalize density before ranking surface results
ASTM D7305 describes reflection-density measurement for printed paper, film or board. Match density before comparing rub, gloss or defects. Different ink transfer can imitate an additive effect. The method is not intended for metal or foil.
Measure rub and blocking separately
ASTM D5264 provides a comparative Sutherland rub practice. Fix receptor, load, cycles and conditioning. Blocking requires a separate test matched to rewind or stack conditions. A surface route can improve block release yet worsen rub, overprint or adhesive-side set-off.
Test the actual ink vehicle and process
ASTM D6687 guides testing of printing-ink vehicles and their components. Build the protocol around flexo, gravure, screen, offset or digital application as appropriate. Record press speed, drying or UV dose and observations through a full production-length run.
Approve conversion and compliance
Run die-cutting, matrix removal, slitting, rewinding and dispensing on the final construction. For shrink or in-mold labels, reproduce heat or molding. None of the public pages proves food-contact, pharmaceutical-contact or low-migration compliance. Obtain relevant declarations and validate set-off and migration risk.
Decision rules
- Confirm the exact 2100 product identity, TDS and COA before a wetting trial.
- Use 3062 only for measured printing-process foam within its published range.
- Do not screen 3501 without a supplier-backed dose and block protocol.
- Reject any change that harms density, adhesion, rub, drying, die-cutting or dispensing.
Information to send with an inquiry
Provide label type, facestock, topcoat and treatment, ink/process, viscosity, deposit, current additives, drying or UV dose, rewind conditions, adhesive/liner, overprint or lamination, conversion method, compliance target and defect photographs.
Ask Longchang for a controlled label ink additive test plan.