{"id":10629,"date":"2026-07-15T00:00:47","date_gmt":"2026-07-15T00:00:47","guid":{"rendered":"https:\/\/longchangchemical.com\/?p=10629"},"modified":"2026-08-05T11:27:48","modified_gmt":"2026-08-05T11:27:48","slug":"flexographic-ink-additives","status":"publish","type":"post","link":"https:\/\/longchangchemical.com\/nl\/flexographic-ink-additives\/","title":{"rendered":"Flexographic Ink Additives: Wetting, Foam & Rub Guide"},"content":{"rendered":"

Choose a flexographic ink additive only after locating the defect in the print process.<\/strong> Poor coverage on film is primarily a wetting problem; persistent air in a recirculating ink is a foam-control problem; and scuffing, blocking, or release after printing is a cured-print surface problem. Treating all three with one \u201csurface additive\u201d usually makes the press trial harder to interpret.<\/p>\n

This system-neutral guide covers water-based, solvent-based, and UV flexographic inks. It compares three Longchang starting routes and shows how to run a controlled press-side screen without confusing additive effects with anilox, plate, viscosity, drying, or substrate-treatment variation.<\/p>\n

Stabilize the flexo process before changing the additive<\/h2>\n

Record ink chemistry, viscosity and measurement temperature, pH where relevant, anilox volume and line count, plate and tape, press speed, drying or UV dose, substrate and surface treatment, and the age of the ink. A change in any of these can move density, trapping, dot gain, laydown, or cure independently of the additive.<\/p>\n

ISO 12647-6:2020<\/a> defines process-control aims and tolerances for four-colour flexographic printing. The Flexographic Technical Association\u2019s FIRST 7.0<\/a> framework likewise emphasizes optimization, fingerprinting, measurement, and repeatable process control. Use the additive trial inside a controlled print condition rather than as a substitute for one.<\/p>\n

\n\n\n\n\n\n\n\n\n
Where the defect appears<\/th>\nEvidence to collect<\/th>\nFirst additive route<\/th>\n<\/tr>\n<\/thead>\n
At initial contact with film or foil<\/td>\nSurface treatment, drawdown coverage, pinholes, adhesion<\/td>\nWetting: CHLUMIWE\u00ae 2100<\/td>\n<\/tr>\n
In the pan, pump, chamber, or return line<\/td>\nFoam height, air entrainment, density\/viscosity drift<\/td>\nDefoaming: CHLUMIAF\u00ae 3062<\/td>\n<\/tr>\n
After drying, curing, rewinding, or finishing<\/td>\nRub, blocking, release, overprint\/lamination result<\/td>\nSurface handling: CHLUMIAG\u00ae 3501<\/td>\n<\/tr>\n
Across the whole press result<\/td>\nAnilox, plate, ink condition, drying, substrate treatment<\/td>\nCorrect process variation before additive screening<\/td>\n<\/tr>\n<\/tbody>\n<\/table>
Original flexo defect-location map: select the additive by where the failure begins.<\/figcaption><\/figure>\n

Quick comparison of three Longchang routes<\/h2>\n\n\n\n\n\n\n\n
Product<\/th>\nPrimary screening job<\/th>\nSupplier use information<\/th>\nTrial watchpoint<\/th>\n<\/tr>\n<\/thead>\n
CHLUMIWE\u00ae 2100<\/strong><\/a><\/td>\nSpreading and wetting on difficult or highly smooth substrates, including PE, PP, polyester, and packaging materials<\/td>\n0.1\u20131% on total formulation; water, solvent, and UV systems<\/td>\nDo not use extra wetting to mask inadequate film treatment; check adhesion, foam, and intercoat compatibility<\/td>\n<\/tr>\n
CHLUMIAG\u00ae 3501<\/strong><\/a><\/td>\nPrinted-face anti-sticking, release, and overprint-varnish compatibility after wetting is acceptable<\/td>\nListed for printing inks, overprint varnishes, release coatings, and water\/solvent\/UV systems<\/td>\nConfirm dosage with the current technical sheet; test blocking, rub, overprint, lamination, and sealing<\/td>\n<\/tr>\n
CHLUMIAF\u00ae 3062<\/strong><\/a><\/td>\nDefoaming and foam suppression where entrained air disrupts ink preparation or circulation<\/td>\n0.1\u20130.5% for printing inks; 100% active; water, solvent, and UV systems<\/td>\nIf pre-diluted, validate stability and defoaming; check craters, haze, density, and later coating\/lamination<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

When CHLUMIWE\u00ae 2100 is the logical first screen<\/h2>\n

Choose the wetting route when a controlled drawdown or press sample retracts, leaves pinholes, produces incomplete coverage, or shows weak initial adhesion on a low-surface-energy film. Confirm the substrate treatment at the time of printing; treatment can decay during storage, and contaminated film can produce the same symptom.<\/p>\n

Run a blank and a low-to-high dosage ladder. Measure coverage, color strength or density, dot or fine-line reproduction, foam, and adhesion after full dry or cure. Stop increasing dosage when coverage is stable: further surface-tension reduction may create foam, intercoat issues, or excessive penetration without improving print quality.<\/p>\n

When CHLUMIAF\u00ae 3062 should move ahead<\/h2>\n

Select the defoamer route when foam persists in the ink preparation, chamber, pump, or return line and creates density variation, pinholes, overflow, or unstable transfer. First repair mechanical air leaks, return-line drop, pump cavitation, and excessive agitation. Then compare 3062 at the lowest effective level.<\/p>\n

Measure knockdown speed and long-term foam suppression separately. Also inspect the dry print for craters, fisheyes, haze, color shift, and adhesion. A fast foam collapse is not a pass if the printed surface becomes defective.<\/p>\n

When CHLUMIAG\u00ae 3501 is the better comparison<\/h2>\n

Move to a printed-face surface route when substrate wetting and foam are already controlled but the dried or cured print still has anti-sticking, release, rewinding, or overprint-varnish problems. Because later lamination, coating, sealing, and tape operations depend on surface condition, include those steps in the trial rather than testing slip or release alone.<\/p>\n

A press-relevant trial sequence<\/h2>\n
    \n
  1. Qualify with drawdowns.<\/strong> Reject combinations that show craters, haze, poor wetting, color change, or loss of adhesion before using press time.<\/li>\n
  2. Run one additive variable at a time.<\/strong> Keep viscosity, pH, temperature, anilox, plate, speed, dryer or UV dose, and substrate lot constant.<\/li>\n
  3. Sample at defined intervals.<\/strong> Collect startup, steady-state, and aged-ink samples to catch recirculation and foam-stability effects.<\/li>\n
  4. Condition before final testing.<\/strong> Many water-based inks need time after printing for final adhesion and resistance development; use the customer\u2019s real converting interval.<\/li>\n
  5. Test downstream operations.<\/strong> Rewind, block, rub, overprint, laminate, seal, or tape the sample as required by the package construction.<\/li>\n<\/ol>\n

    For laboratory comparison of abrasion on printed materials, ASTM D5264<\/a> describes the Sutherland rub tester and highlights the effects of shipment, storage, and handling. For resistance to liquids, solvents, varnishes, and other agents, ISO 2836:2021<\/a> provides applicable methods for flexo and other print processes. Neither reference establishes food-contact compliance.<\/p>\n

    What to report after the trial<\/h2>\n