Waterborne flexographic ink additives should be chosen from the press failure, not from a generic ranking. Poor film entry can justify a 2100 wetting-grade trial, recirculation foam can justify a 3062 trial, and blocking may justify an evidence-gated 3501 study. First lock substrate treatment, pH, viscosity, anilox, speed and drying.
Screen the 2100 wetting grade after identity confirmation.
Screen 3062.
Gate 3501 by dose and a defined protocol.
Resolve the 2100 identity before purchasing
Longchang currently has two distinct live product records for a similar 2100 wetting grade: one is titled CHLUMIAG® 2100 and another is titled CHLUMIWE® 2100. The public site therefore does not establish one unambiguous current brand identity. Put the product code, current commercial name, TDS revision and COA on every sample request before testing or purchase.
Stabilize the press variables first
Record substrate polymer, coating or treatment level, ink chemistry, pH, temperature, viscosity method, anilox volume, plate, impression, speed, dryer settings and recirculation design. Check treatment immediately before printing. Decayed corona, excessive viscosity drift, dirty cells, poor doctoring or insufficient drying can resemble an additive problem.
Compare the three routes
| Route | Published evidence | First experiment | Do not assume |
|---|---|---|---|
| 2100 wetting grade | Two conflicting live product identities; similar wetting role for difficult packaging substrates | Retraction, coverage and print laydown after exact identity confirmation | Do not assume which brand page or document applies to the supplied lot |
| CHLUMIAF® 3062 | 100% active; water/solvent/UV systems; 0.1–0.5% total for printing ink | Foam and air-linked print defects | Not a substitute for substrate wetting or dry-web release |
| CHLUMIAG® 3501 | 100% active; printing ink, overprint varnish and release/anti-sticking uses | Supplier-supported blocking or release study | No public recommended dosage or quantified block/rub result |
Use the 2100 grade for a reproduced wetting failure
After the supplier confirms which 2100 record and document set match the material, screen it only when ink beads, retracts or transfers unevenly on a verified substrate. Keep pH, viscosity, anilox volume and drying fixed. Measure density, pinholes, line and dot quality, tape adhesion, rub and lamination or overprint compatibility. Better spread does not prove stronger adhesion.
Use 3062 for recirculation air
3062 has the clearest published printing-ink dose: 0.1–0.5% of total formulation. Identify where air enters—the mix tank, pump, chamber, return line or doctoring zone—and compare foam height, wet density and decay at fixed times. The page says solvent dilution requires stability and defoaming-performance testing, so record diluent, ratio, order, shear and aging.
Keep 3501 behind an evidence gate
3501 may fit blocking or release complaints, but its public page provides no recommended dosage and no pressure/temperature/time protocol. Request the current TDS, a starting range, compatible vehicle classes and a reproducible block method. First exclude incomplete drying, retained water, warm rewinding, excessive roll hardness and high storage temperature.
Use a controlled flexographic matrix
| Press trial | Change | Primary measure | Downstream gate |
|---|---|---|---|
| A | Unchanged control | Density, foam, wetting, drying and block baseline | Adhesion, rub and conversion |
| B–D | Confirmed 2100 grade low/mid/high | Coverage, pinholes and line/dot quality | Adhesion, overprint and lamination |
| E–G | 3062 within 0.1–0.5% | Foam, wet density and press stability | Print density, crater and storage |
| H–J | 3501 only after data approval | Block at fixed pressure, temperature and time | COF, rub, adhesion and seam |
Normalize density before comparing appearance
ASTM D7305 describes reflection-density measurement for printed matter on paper, film or board. Match density before ranking gloss, rub or pinholes; different ink transfer can imitate an additive effect. The method is not intended for metal or foil, so select another documented method for those substrates.
Measure rub independently from blocking
ASTM D5264 provides a comparative Sutherland rub practice. Fix receptor, load, cycles and conditioning. Blocking needs a separate simulation using the actual rewind or stack pressure, temperature and dwell. A surface route can improve release while reducing rub or overprint adhesion, so approve both outcomes.
Build the protocol around the real ink vehicle
ASTM D6687 is a current guide to testing printing-ink vehicles and their components. Use it to structure repeatable comparisons while preserving production-relevant resin, pigment, pH control and drying. Record observations over the full press run, because foam and viscosity drift may appear only after circulation.
Do not infer packaging compliance
The public product pages do not establish food-contact, pharmaceutical-contact, low-migration or destination-market compliance for a finished package. Map direct contact, indirect contact and set-off routes; obtain the applicable composition and regulatory declarations; and validate the complete printed and converted construction.
Decision rules
- Do not order the 2100 grade until the supplier confirms the exact product identity, TDS and COA.
- Use 3062 for measured process foam within its published printing-ink range.
- Do not run 3501 at an invented equal dose; require a supplier-backed starting range and block method.
- Reject any change that improves one symptom but harms density, adhesion, rub, drying or conversion.
Information to send with an inquiry
Provide ink vehicle, substrate and treatment, pH and viscosity history, anilox, speed, drying, recirculation layout, current additives, density target, rewind conditions and defect photographs. State whether the failure is wetting, foam, drying, blocking, rub or adhesion.
Ask Longchang for a controlled waterborne flexographic ink additive test plan.