Waterborne Flexo/Gravure Ink Microfoam Challenge: Toynol® Foamic 024 High-Efficiency Defoaming Solution

Background & Problem: Why Microfoam Becomes a Production Bottleneck

In flexographic and gravure waterborne printing processes, inks subjected to high-speed agitation and circulation pumping entrain large quantities of micro-sized air bubbles. If these microfoams are not promptly eliminated, they lead to:

• White spots, pinholes, or fisheyes on printed matter
• Uneven hiding power of the print surface
• Poor ink transfer, impairing pattern sharpness
• Press stoppages for bubble removal, reducing production efficiency

Traditional silicone-based defoamers can break bubbles but often induce cratering or ink re-coarsening, becoming new defect sources, especially in high-gloss inks.

Limitations of Tego 825 & Need for a Replacement

Tego 825 is an acetylenic diol-based foam control agent that combines wetting and defoaming functions. However, under intense shear mixing and high-speed printing conditions, its bubble-breaking speed and persistence often fall short of expectations. User feedback includes:

• Insufficiently fast bubble break, leaving microfoam residues that cause printing defects
• Short foam suppression duration, requiring frequent re-dosing
• Reduced compatibility in certain waterborne ink systems, causing slight haze

Therefore, the industry urgently needs a domestic alternative that offers quick bubble break, thorough defoaming, and good compatibility.

Core Solution: Toynol® Foamic 024 High-Efficiency Waterborne Polymeric Defoamer

Product Positioning: Nonionic organic polymeric defoamer, free of silicone, mineral oil, and APEO, designed specifically for waterborne inks, coatings, and adhesives.

Key Performance Indicators:

• Fast Bubble Break: At 0.2%–0.5% addition, eliminates over 90% of agitating microfoam within 30 seconds, with foam suppression lasting over 30 minutes
• Microfoam Terminator: Its hydrophilic molecular structure penetrates and envelops fine bubbles in inks/resins, causing rapid coalescence and rupture
• High Compatibility: Minimizes cratering, pinholes, or re-coarsening; especially suitable for flexo/gravure varnishes demanding stringent surface quality
• Free of Silicone Oil & Mineral Oil: Eliminates cratering risks and does not affect ink gloss or adhesion

Practical Application Guide

1. Addition Timing: Recommended to add at the final stage of ink formulation, or as a post-additive to already stirred ink, mixing at low speed.

2. Recommended Dosage: 0.2%–1.0% based on total ink weight. For highly foaming systems (e.g., those containing large amounts of acrylic resin or multiple surfactants), start at 0.5%.

3. Formulation Adjustments to Replace Tego 825:

• If the original formula uses Tego 825 solely as a defoamer, replace it with an equal amount of Foamic 024, and evaluate bubble break speed and foam suppression persistence.
• If Tego 825 also serves as a wetting agent in the system, retain 0.1%–0.2% Tego 825 and supplement with 0.3%–0.5% Foamic 024 for a synergistic “wetting + strong defoaming” effect.

4. Precautions:

• Avoid addition during the grinding stage, as it may reduce defoaming efficiency.
• For first trials, perform a dosage screening (0.2%, 0.5%, 0.8%) to determine the optimal level.

Wetting Synergy: Tackling Stubborn Microfoam

If microfoam persists or dynamic wetting is insufficient, combine the following additives for a “wetting-defoaming” synergy:

• Toynol® Superwet-320: 0.3%–0.5% (high-efficiency low-foam acetylenic diol wetting agent, helps eliminate pinholes)
• Toynol® FS-620: 0.3%–0.5% (acetylenic diol polyether foam-control wetting agent with both foam control and wetting)

Especially in high-speed gravure printing (line speed >100 m/min), FS-620 effectively lowers dynamic surface tension, and in conjunction with Foamic 024’s fast bubble break, enables defect-free production.

Performance Comparison Test Recommendations

Engineers are advised to evaluate using a “static defoaming test” (graduated cylinder method) and a “dynamic circulation test” (simulating printing pump conditions):

1. Static Defoaming Test: Prepare 200 ml of test ink, high-speed stir for 5 minutes to generate microfoam, record the time for foam layer disappearance after adding 0.5% defoamer. Foamic 024 typically <10 seconds, Tego 825 approx. 25–35 seconds.

2. Dynamic Circulation Test: Use a small circulation pump to simulate printing conditions, circulate for 10 minutes, take photos of the ink surface foam every minute, and calculate the foam residual coverage.

Conclusion

Toynol® Foamic 024, with its three core advantages—fast bubble break, long-lasting foam suppression, and high compatibility—is a suitable option designed to replace Tego 825. It is specifically formulated to solve microfoam challenges in waterborne flexo/gravure inks. Combined with wetting agents such as Superwet-320 or FS-620, it builds a complete foam control and wetting system.