Ultrasonic Cleaning in the Graphic Industry — Complete Guide

The graphic and printing industry thrives on precision, repeatability, and uptime. From anilox rolls and screens to ink delivery components and printheads, even microscopic deposits can degrade print density, color accuracy, and registration. Ultrasonic cleaning offers a fast, non-destructive, and highly repeatable way to restore components, reduce waste, and keep presses running at peak performance.

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What Is Ultrasonic Cleaning?

Ultrasonic systems use high-frequency sound waves (typically 28–80 kHz) to generate millions of microscopic bubbles in a liquid bath. These bubbles form and collapse in a process called cavitation, releasing localized energy that lifts dried inks, coatings, adhesives, pigments, resins, and paper dust from surfaces — including deep cells, meshes, and micro-crevices — without abrasion.

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Where Ultrasonic Cleaning Fits in Printing Workflows

• Anilox roll cleaning: Remove dried ink/coatings from cell structures to restore true cell volume (BCM/cm²) and consistent ink transfer.
• Screen printing: Deep-clean mesh to eliminate ghosting, retain tension performance, and extend screen life.
• Stencils & plates: Clear solder paste/adhesive or coating residues without undercutting fine features.
• Ink delivery parts: Pumps, nozzles, hoses, doctor blade holders, chambers, and trays — remove build-up that causes flow variation and color drift.
• Printheads & precision components: Where permitted by OEM guidance, restore or prepare housings and fixtures used around heads; use approved chemistries and parameters.

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Key Benefits for the Graphic Industry

• Improved print quality: Clean components deliver stable density, sharper detail, and accurate color reproduction.
• Faster turnarounds: Batch processing reduces cleaning labor and press downtime.
• Non-destructive: No mechanical scrubbing — protects engraved cells, meshes, plates, and seals.
• Lower costs & waste: Less rework, fewer rejects, longer component life.
• Eco-friendlier: Typically uses less water and chemistry than soak/scrub methods.

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Recommended Process Parameters

• Frequency: 28 kHz for heavy deposits on robust parts; 40 kHz as the all-round standard; 80 kHz+ for delicate meshes and fine engravings.
• Temperature: Usually 40–60 °C to enhance wetting and cavitation. Avoid temperatures that could distort polymers or seals.
• Time: Start with 3–10 minutes and adjust to soil load; verify with cleanliness checks (e.g., cell volume recovery).
• Chemistry: Use task-specific ultrasonic concentrates compatible with substrates.
• Degas: Run Degas mode after filling to remove dissolved gases and stabilize cavitation.
• Fixturing: Position parts to avoid “shadowing”; ensure full immersion and line-of-sight to transducers.

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Validated Workflow (Step-by-Step)

1. Pre-inspection: Note ink type (water/solvent/UV), coating, and substrate; protect bearings and sealed areas if needed.
2. Bath setup: Fill with DI or clean water; add concentrate to the target dilution; degas the bath.
3. Load & clean: Place parts in baskets/racks; set frequency, temperature, and timer. Avoid overloading.
4. Rinse: Rinse with clean or DI water; for critical parts, use a second ultrasonic rinse.
5. Dry: Use filtered air or warm drying; ensure no moisture remains in cells or meshes.
6. Verify: For anilox, verify cell volume/BCM; for screens, check open area and tension; for plates/stencils, inspect edges and apertures.
7. Record: Log parameters (bath age, dilution, temp/time) to support consistency and audits.

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Choosing the Right Cleaning Chemistry

Match chemistry to soil and substrate to maximize performance and protect assets. ASONIC concentrates are formulated for ultrasonic cavitation and stability:

Cleaner	Target Soils	Compatible Materials	Dilution	Temp.
AS-MLP	Oil, grease, dust, general ink residues	Metals, alloys, plastics, rubber, ceramics, glass	2%	40–60 °C
AS-GEN	General inks/coatings, grime, paper dust	Metals, alloys, plastics, rubber, ceramics, glass	5%	40–60 °C
AS-CARB	Heavy polymerized deposits, carbonized inks	Robust metals (incl. aluminum, brass) & sensitive alloys	10%	50–60 °C
AS-OXI	Oxidation, stubborn residues	Iron, copper, tin, aluminum, stainless steel	10%	40–60 °C
AS-SENS	Light oils/grease; sensitive components	Brass, aluminum, tin, mixed alloys	10%	50–60 °C

Good practice: Monitor bath life (conductivity or titration), filter particulates, and change solutions on schedule to maintain consistent results.

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Best Practices & Safety

• Follow OEM guidance for anilox, screens, and heads; validate parameters before production use.
• Avoid aggressive chemistries on aluminum, adhesives, elastomers unless confirmed compatible.
• Prevent cross-contamination: separate water-based vs. UV/solvent ink loads; keep dedicated baskets.
• Train operators on PPE, handling, and spill response; ensure proper ventilation.
• Implement QC metrics: BCM recovery, ΔE color stability, screen open area, and defect rate before/after cleaning.

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Common Issues & Troubleshooting

• Streaks or uneven results: Re-degas the bath, reduce overloading, reposition parts for better cavitation exposure.
• Residue remains in cells/mesh: Increase time slightly, verify dilution/temperature, consider a targeted pre-soak.
• Foaming: Lower temperature, adjust chemistry, or reduce agitation; check for contamination by surfactants.
• Surface dulling: Reduce time/temp or choose a gentler concentrate (e.g., AS-SENS).

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FAQ — Ultrasonic Cleaning for the Graphic Industry

Will ultrasonics damage anilox engravings?
No, when using the correct frequency, chemistry, and exposure time. It’s non-abrasive and preserves cell geometry while restoring volume.

Can I clean UV inks ultrasonically?
Yes — select compatible chemistry (often higher pH or specialty blends) and validate the cycle; dispose of waste per local regulations.

How often should I clean?
Adopt a preventive schedule (e.g., per shift/day) to keep cells/meshes open and avoid heavy polymerization that requires longer cycles.

Which frequency is best?
40 kHz is a solid standard; move to 80 kHz for delicate meshes and fine features, or 28 kHz for heavy deposits on robust parts.

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Conclusion

Ultrasonic cleaning is a proven, non-destructive solution for maintaining anilox rolls, screens, stencils, pumps, trays, and precision components. It boosts print quality, shortens maintenance time, and reduces costs and waste. With the right system setup and ASONIC concentrates, print providers can standardize cleanliness and elevate production consistency.

Ready to optimize your pressroom cleaning? Contact us at order@asonic.si or explore the ASONIC PRO Series Ultrasonic Cleaners to build a high-performance, validated workflow.