Paper bag ink additives should be selected after separating substrate wetting from process foam. CHLUMIWE® 3280 is the difficult-surface wetting route. CHLUMIAF® 3062 is the foam-control route. Neither replaces drying, cure, rub, adhesion, blocking or converting validation.
CHLUMIAG® 3501 is removed from the first shortlist because its public page lists printing and anti-sticking applications but publishes no recommended dosage or quantified rub, blocking or bag-handling endpoint.
Paper bag ink decision map
| Observed failure | First evidence check | Rute |
|---|---|---|
| Ink beads, skips fibers or pulls back on kraft/coated paper | Paper lot, treatment, ink surface tension, viscosity and film weight | 3280 |
| Foam rises in mixing, pump, chamber or return | Density, foam generation/decay and cured voids | 3062 |
| Printed face scuffs or offsets | Drying/cure, residual water/solvent, film weight and stack conditions | Fix ink/process before surface additive |
| Cracking or adhesion loss during bag forming | Paper fold, ink flexibility, cure and converting geometry | Reformulate and retest the complete ink |
| Produk | Published fit | Supplier guidance | Boundary |
|---|---|---|---|
| CHLUMIWE® 3280 | Wetting agent for inks/UV-water systems; UV, solvent and water-based compatibility | 0.2–3% total; grind, stir or post-add; broad dilution options | Does not increase slip or affect recoatability per page; avoid mixing |
| CHLUMIAF® 3062 | 100% active nonionic silicone defoamer; printing/color systems | Printing inks 0.1–0.5% total; UV, solvent and water-based | Use only for measured air; solvent dilution needs stability/performance tests |
| CHLUMIAG® 3501 | Printing, overprint varnish, release and anti-sticking applications listed | Any-stage addition; UV, solvent and water-based | No public recommended dosage or quantified paper-bag handling result |
Characterize the bag paper first
Record kraft or coated grade, recycled fiber, sizing, porosity, moisture, surface treatment, corona age where used, print side, dust, paper temperature and lot. A quick drawdown on smooth white stock does not reproduce absorbent kraft, seams, folds or high ink coverage.
Use the real printing method and anilox/plate/screen conditions. Hold viscosity, pH where applicable, temperature, press speed, film weight and drying energy before judging an additive.
Condition paper and printed specimens at defined temperature and humidity before comparison. Paper moisture changes absorbency, dimension, fiber strength and apparent drying; testing one candidate on dry stock and another after humid storage can reverse the ranking without any additive effect.
Use 3280 for confirmed wetting failure
3280 is a 100%-active polyether-modified polysiloxane with a broad 0.2–3% range. Its page supports difficult-substrate wetting, pinhole prevention and leveling, while stating that it does not increase slip or affect recoatability.
Start at the low end after paper variability and contamination are controlled. Measure contact/coverage, edge definition, mottle, pinholes, color density, drying, adhesion, rub, block, glue acceptance and fold performance. Wetting improvement is not proof of durability.
Use 3062 only when air is measured
3062 is a true defoamer route, not a substitute for wetting or cure. Track foam after high-speed mixing, pumping, chambering and return. Compare wet bubbles with cured pinholes so air is not confused with dewetting or paper outgassing.
If solvent dilution is used, follow the product-page instruction to test dilution stability and defoaming performance. Select the lowest dose that controls air without creating craters, gloss loss, poor adhesion or color variation.
Why 3501 is not a first recommendation
The 3501 page supports broad printing and anti-sticking application categories but supplies no recommended dosage and no quantified rub, blocking, release or bag-converting endpoint. It therefore needs a current TDS and application-specific trial before entering a shortlist.
Measure rub and blocking separately
ASTM D5264 provides a controlled Sutherland rub comparison for printed materials, including packaging substrates. ASTM D5181 uses a GA-CAT abrasion tester for printed matter, inks and varnishes on flat substrates. Neither reproduces every bag shipment, fold or contamination condition.
Define receptor, load, cycles, conditioning and evaluation. For blocking, define face-to-face/face-to-back contact, pressure, temperature, humidity and dwell. Inspect ink transfer, gloss marking, fiber tear and odor after separation.
Test the converting sequence
- Print production paper at controlled film weight.
- Dry or cure under the real line window.
- Condition before stacking, rubbing and folding.
- Run creasing, folding, gluing, handle cutting and filling simulations as applicable.
- Repeat after storage at the expected temperature and humidity.
Record crack whitening, ink pick, glue failure, scuff, offset, odor and appearance. The bag is the test article; a flat drawdown is only an early screen.
Repeat critical checks on high and low ink coverage, seam areas and folds that run with and across the paper grain. Bag geometry can concentrate strain where a flat sheet appears acceptable.
Keep compliance claims product-specific
A general additive page does not establish food contact, low migration, compostability, recyclability or restricted-substance compliance. Define the market, bag use, barrier, ink layer and customer specification, then request current declarations for the exact additive and use level.
Request a paper-bag ink shortlist
Send the paper grade/lot, printing process, ink chemistry/solids, pigments, current additives, viscosity/pH, film weight, drying/cure, circulation conditions, defect photos, and wetting, foam, rub, block, fold, glue and compliance requirements. Ask Longchang Chemical to compare 3280 and 3062.