CIJ Inks, Make-Up & Cleaners
A field guide to Continuous Inkjet (CIJ) fluids: how inks, make-up and cleaners co-operate as a closed-loop system; how to choose solvent families (MEK/ethanol/acetone/water), manage viscosity and uptime, de-risk condensation zones, select pigmented whites for high opacity, and navigate OEM vs compatible sourcing with safety and compliance intact.
Why CIJ fluids are a system, not commodities
CIJ’s promise—tiny characters at high line speed, on curved/fragile/wet surfaces—relies on a coupled system: ink provides color and polymer film; make-up maintains μ (viscosity) and κ (conductivity) in a tight band despite evaporation; and cleaner resets the head surface, dissolving deposits without attacking plastics, sealants, or the cured film. If any leg drifts, the process window collapses: break-off phase shifts, charge scatter grows, drops miss the target line and hit the gutter, and clogs compound. For the broader consumables landscape (CIJ/TIJ/TTO/Laser), see Coding & Marking Consumables; solvent families are mapped in CIJ Ink Families: MEK vs Ethanol vs Dye-Pigment.
System KPIs
Beyond ±7%: charge errors & scatter ↑. Diagnostic steps in CIJ Print Quality Troubleshooting Checklist.
Baseline ml/h
40–60 µm → 12–35 ml/h depending on VI & duty. Plan with Make-Up Consumption.
Condensation guard
Coding through micro-film moisture? See Adhesion on Wet PET & Glass: Surface Energy Tricks.
White & UV strategy
Opaque or covert codes: High-Contrast White & UV-Readable Inks.
HAZMAT
Export/DDP and UN labels: Solvent Safety & MSDS, Hazmat Labels & UN Numbers.
Kitting
Reduce stops via pre-kits: Fluids + Filters + Maintenance Kit.
Process window (schematic)
| Variable | Nominal band | Effect out-of-band | Mitigation |
|---|---|---|---|
| μ (viscosity) | ±5% | Charge phase drift; dot scatter | Correct make-up; temp/airflow |
| κ (conductivity) | OEM spec | Charging fault; deflection error | Paired fluids; no ad-hoc solvent |
| σ (surface tension) | Recipe set | Satellite drops | Recipe integrity; filter discipline |
f_b ≈ v/λ, jet velocity v ≈ √(2ΔP/ρ). As μ increases,
v falls → f_b shifts → charging phase error.
Line Health Snapshot
Ink chemistry: solvent, colorant, binder, additives
CIJ ink balances four domains. Vehicle (MEK/ethanol/acetone/water) sets evaporation and substrate “bite”. Colorant (dye/pigment) determines hiding power and vision readability. Binder (NC, acrylic, ketone resin, PU, etc.) locks the film after dry and shields against wipes/wash. Additives (wetting agents, humectants, conductivity salts, dispersants, defoamers) fine-tune jetting, charge response and film leveling. Compare families in CIJ Ink Families: MEK vs Ethanol vs Dye-Pigment. For dark plastics/cables, explore High-Contrast White & UV-Readable Inks: Use Cases; for cold-fill PET/glass, see Adhesion on Wet PET & Glass.
Core families & typical strengths
| MEK | Fast dry; excellent on PET/PVC; popular default for FMCG primaries. |
|---|---|
| Acetone | Ultra-fast for max line speeds; manage odor & enclosure air. |
| Ethanol | Lower odor; slower dry; favored in food/pharma windows. |
| Water | Porous media; consider TIJ unless CIJ is required. |
Dye vs pigment — operational trade-offs
| Dark substrate contrast | Pigment ★★★★☆ / Dye ★☆☆☆☆ |
|---|---|
| Maintenance | Pigment ▲ (agitation) / Dye ▼ (lower) |
| Camera/OCR | Pigment excels; dye may bloom on glossy films |
| Idle risk | Pigment settling if long idle; dye lower hiding power |
Binder picks
NC/ketone for fast tack; acrylic for clarity/adhesion; PU where toughness needed.
Anti-condensation
Special grades tolerate micro-water film; pair with dewatering and air knives.
Vision readiness
Camera contrast (CR) depends on pigment quality & film thickness—validate with your optics.
Substrate × ink family — starting matrix
| PET (cold/wet) | MEK fast-dry or ethanol low-odor anti-condensation grades |
|---|---|
| HDPE/PP | Surface-energy limits → specialty adhesion promoters or pre-treatment |
| Glass (cold) | Condensation-tolerant MEK/ethanol; dry path and airflow matter |
| Aluminum | MEK/acetone often fine; consider post-wash resistance |
Ink Family Quick Selector
Make-up: viscosity control as closed-loop reliability
Make-up is not “extra solvent”. CIJ continuously measures μ and κ, dosing make-up to counter evaporation. Because binders/pigments evaporate slower than solvent, the ink richens over time; paired make-up brings it back. Random ethanol in a MEK system? Expect haze, flocculation, filter loading, and phase errors. For budgeting, use the calculator at Make-Up Consumption: ml/Hour by Nozzle & Duty Cycle, then reconcile with your line logs.
Typical solvent indices (VI) & planning
| Solvent base | VI | Usage note |
|---|---|---|
| Acetone | 1.20 | Top speed; high ventilation control |
| MEK | 1.00 | Balanced speed/handling; common default |
| Ethanol | 0.70 | Low odor; slower dry; tighter windows |
| Water | 0.20 | Porous media niche; TIJ often superior |
Heuristic: Make-Up (ml/h) ≈ BaseRate(nozzle) × Duty × VI
with BaseRate @ 23°C: 40 µm ≈ 15; 50 µm ≈ 22; 60 µm ≈ 30.
Ambient swing
Every +5°C → +10–20% usage for fast solvents.
Seal/park
Seal-tronic/valves curb drift in micro-stops; cheaper than deep purges.
Filter ΔP
ΔP increases pressure noise → drop size variance; swap on hours/ΔP trend.
QA tie-in
Correlate μ log with camera CR score from Troubleshooting Checklist.
Logging template
| Time | μ | κ | Ambient °C | ml/h | Alarms | Operator |
|---|---|---|---|---|---|---|
| 08:00 | +2% | 1.00 | 22 | 18 | — | AB |
| 12:00 | +4% | 1.01 | 27 | 21 | Visc warn | AB |
Ambient Correction for Make-Up
Cleaners: preventative maintenance & safe handling
Cleaners mirror the ink’s vehicle to dissolve dried residues at the nozzle/charge electrode/gutter. Wrong cleaner attacks binders, smears prints, or swells plastics. Treat as Class IB flammables (MEK/acetone): ventilation, ignition control, and bonding/grounding. For export/DDP packaging, see Solvent Safety & MSDS; for UN labels/PG, see Hazmat Labels & UN Numbers.
Handling checklist
| Ventilation | Local exhaust at service zone |
|---|---|
| PPE | Goggles/face shield; nitrile/butyl gloves; apron |
| Transfer | Bond/ground; approved pumps; no pressurized drums |
| Spill | Kill ignition; inert absorbent; labeled waste |
Compatibility cues
| MEK ink | MEK-based cleaner |
|---|---|
| Ethanol ink | Ethanol-based cleaner |
| Pigmented white | Dispersant-balanced variants |
Startup benefit
| Right cleaner | Fast first-good-print |
|---|---|
| Wrong cleaner | Smear/adhesion loss |
Training
QR-link SDS at line; laminate a one-page wipe/purge SOP.
Nozzle life
Gentle frequent cleans > rare aggressive wipes (orifice scratch risk).
Waste
Segregate by solvent; manifests with lot/date ↔ traceability.
Cleaner Picker
Interactive: Make-Up Consumption Estimator
Estimate hourly make-up usage from nozzle size, duty cycle and solvent base (heuristic planning only).
Make-Up Consumption (ml/h)
Interactive: Condensation Adhesion Selector
Pick substrate/conditions to get suggested CIJ ink families for wet-surface coding (cold-fill PET/glass).
Wet Surface Adhesion — Ink Suggestor
Interactive: OEM vs Compatible — Risk-Benefit Lens
Compare risk classes across uptime, compliance, TCO and warranty exposure. Deeper sourcing playbook: Compatible vs OEM Fluids: Risk-Benefit Matrix.
OEM vs Compatible Risk-Benefit
Interactive: White Ink Opacity Requirement Estimator
Estimate the opacity target for pigmented white CIJ inks on dark substrates; outputs CR target and a heuristic opacity class.
White Ink Opacity Requirement
Failure chains & preventive playbook
Stoppages typically trace to solvent drift → μ↑ → phase/deflection errors → overspray → fouling. Build a prevention rhythm: daily wipe; weekly filter checks; monthly μ/κ audit; seasonal ambient review. For startup SOPs, see Nozzle Clogging & Startup Failures: Preventive Playbook; for camera-critical marks, use CIJ Print Quality Troubleshooting Checklist.
Failure chain map
| Trigger | Immediate effect | Downstream symptom | Fix |
|---|---|---|---|
| Viscosity +8% | Break-off advance; phase error | Deflection scatter; overspray | Restore μ; head clean; verify make-up ID |
| Wrong cleaner | Binder attack | Smearing; adhesion loss | Switch to paired cleaner; retrain |
| Condensation | Film under drops | Dull/bleed codes | Dewater/warm; anti-condensation grade |
| Filter overdue | ΔP rise | Pressure oscillation; drop variance | Swap on hours/ΔP trend |
Daily
Head wipe; μ/κ within band; alarms check.
Weekly
Filter ΔP review; sample grid print; camera score.
Monthly
Ambient & ml/h correlation; adjust airflow.
Fault Classifier
Storage, shelf life & temperature control
Store cool, dry, ventilated; segregate flammables; rotate FIFO; log open dates. Pigmented whites need recirculation after long idles. For deeper policy patterns, see Ink Shelf Life, Storage & Temperature Control. When kitting spares with fluids, consider CIJ Fluids + Filters + Maintenance Kit.
Execution checklist
| Storage | Locked flammables; temperature-controlled; no sunlight |
|---|---|
| Shelf life | Respect lot expiry; avoid mixing lots without validation |
| Open-cartridge log | Date/time; operator; line ID; discard policy |
| Transport | UN numbers/PG; labels; see Hazmat UN Numbers |
FIFO
Scan codes to enforce rotation; old stock ↑ gel/settle risk.
Thermal
Avoid warm rooms cycling; evaporation ↑ and μ control suffers.
White idle
Agitate/recirculate; print a purge strip before production.
FIFO / Months of Stock
Line integration: environment, speed, and code robustness
Mechanics matter. Keep throw distance 2–4 mm for small character, stabilize the head, shield crossflow, align orthogonally to motion. For wet PET/glass, combine mechanical dewatering with ink families from Adhesion on Wet PET & Glass and validate with the Troubleshooting Checklist.
Quick integration map
| Throw distance | 2–4 mm small character; larger for macro codes |
|---|---|
| Head angle | Orthogonal; micro-tune for dot placement |
| Air | Shield drafts; light positive pressure in enclosure |
| Vision | Calibrate camera & lighting; CR target depends on optics |
J ≈ √(j_mech² + j_air²); chemistry cannot compensate excessive mechanical jitter.
Throw Distance Optimizer
TCO lens: fluids, filters, downtime and reject costs
Fluids are leveraged insurance. Small per-liter savings are overwhelmed by reject and downtime costs. In regulated windows (retort/sterile), align with Compatible vs OEM Risk-Benefit. For continuity, pre-kit Fluids + Filters + Maintenance.
Annual TCO ≈ (Ink L/y × Ink $/L) + (MU L/y × MU $/L) + (Cleaner L/y × CL $/L)
+ Filters/parts
+ Downtime (min/y × $/min)
+ Rejects (units/y × $/unit)
TCO Quick Calculator
Regulatory & compliance compass
- Food/pharma inks: align with EuPIA guidance, supplier DoCs, and migration testing per substrate/line.
- Worker safety: HazCom training; SDS access at line; flammables handling; shipping per UN numbers/PG in Hazmat UN Numbers and export packing in Solvent Safety & MSDS (DDP).
- Traceability: lot-to-order linkage; manifests with batch/date; keep labels in sync with SDS.
Interactive: Solvent Exposure / PPE Selector
Heuristic selector for minimum PPE class by solvent and task intensity.
Solvent Exposure / PPE Selector
GMP docs
Capture supplier DoCs with each batch; file into QMS lot history.
Label hygiene
Match in-plant labels to SDS; add QR to intranet SDS portal.
Recall scope
Lot-to-order mapping reduces recall volume and investigation time.
Quick formulas
Jet velocity: v ≈ √(2ΔP/ρ) // ΔP pump pressure; ρ density
Weber number: We = ρ v^2 d / σ // droplet stability (d nozzle dia, σ surface tension)
Ohnesorge: Oh = μ / √(ρ σ d) // viscous-to-inertial-capillary balance
Reynolds: Re = ρ v d / μ // inertial vs viscous
Charge window: keep μ in ±5% and κ within spec // outside window → phase error & scatter
Opacity target (heuristic): CR_target ≈ f(L*, t) // darker substrate & thinner film → higher CR
FAQ
Can I run ethanol make-up with a MEK ink?
No. Cross-family swaps precipitate binders and flocculate pigments—stick with the paired make-up.
Do pigmented whites need extra maintenance?
Yes: recirculation/agitation SOPs; avoid long parks; use matched cleaner—then confirm with Print Quality Checklist.
How do I code on wet PET/glass?
Use condensing-environment grades; move print after dewatering; fine-tune matrix and stroke—see Adhesion on Wet PET & Glass.
When are compatibles acceptable?
Low-risk, non-sterile FMCG primaries or secondaries after trials with reject/uptime targets in PO. Retort/sterile → OEM by default (matrix).
References
- Videojet — CIJ Inks & Fluids Portfolio (2024)
- Videojet iQMark™ Supplies — No-MEK Overview (2024)
- Videojet V901-Q Cleaner — SDS (2023)
- Domino Ax-Series — CIJ Product Brochure (2021)
- Leibinger JET3up — Sealtronic Nozzle Seal (2017)
- Hitachi UX Series — CIJ Brochure (2021)
- EuPIA — Guideline on Printing Inks for Food Contact Materials (2023)
- OSHA — Flammable Liquids (29 CFR 1910.106) Training Guide (2016)
- NIOSH — MEK (2-Butanone) Method 2500 & Exposure Limits
- Videojet — Safety Data Sheets Portal (live)
- Markem-Imaje — Product Safety & Compliance (EuPIA GMP)
- CFR — 29 CFR §1910.106 Flammable Liquids (2020)
