Videojet 43S Inkjet Printer Cleaning: A Complete Maintenance Guide for Production Teams

Regular cleaning is the single most effective thing an operator or maintenance technician can do to keep a Videojet 43S running reliably. It sounds like a straightforward statement, but on a machine where ink circulates continuously through a nozzle orifice smaller than a human hair, cleanliness isn’t optional — it’s the foundation of consistent print quality, uptime, and component longevity.

The Videojet 43S is a well-established small character CIJ (continuous inkjet) printer, widely used across packaging, food and beverage, pharmaceutical, and industrial manufacturing lines for date coding, batch coding, and product traceability. Its self-cleaning printhead design reduces the frequency of manual intervention compared to older platforms, but it does not eliminate it. Understanding when and how to clean the machine properly — both through the built-in software functions and by hand — is essential knowledge for anyone responsible for maintaining one.

This article covers the full cleaning scope for the Videojet 43S: the nozzle flush procedure, manual printhead cleaning, the key components to inspect, what goes wrong when cleaning is neglected, and how to build a maintenance schedule that keeps the machine performing at its best.

Understanding Why the 43S Needs Regular Cleaning

The Videojet 43S operates on continuous inkjet principles. Ink is pressurised and pushed through a small nozzle, broken into individual droplets by a piezoelectric crystal (modulator), electrostatically charged, deflected toward the substrate for printing, and the unused drops are recovered through the gutter and returned to the ink system. This process runs continuously whenever the jet is active — typically for entire production shifts.

Several aspects of this process generate cleaning requirements:

Ink residue accumulation — Every startup and shutdown cycle, and any moment where the jet is briefly disrupted, can deposit microscopic amounts of ink on the charge electrode, gutter entrance, deflection plates, and nozzle face. Over time these deposits build up, alter the electrostatic charge field, and interfere with accurate drop deflection.

Solvent evaporation at the nozzle face — The solvent component of the ink evaporates quickly when exposed to air. At the nozzle exit, ink exposed to the environment between production runs can dry and partially crystallise, forming a partial blockage that changes the jet’s velocity and trajectory even if it doesn’t fully block the orifice.

Environmental contamination — In food production, packaging, and industrial environments, airborne dust, product particles, and moisture can enter the open printhead cavity during operation. These contaminants mix with ink residue to form harder deposits that are more difficult to remove later.

Gutter and charge electrode fouling — The charge electrode applies a precise electrical charge to each droplet. Any ink bridging across the electrode slot short-circuits the charging process, causing charging errors and EHT (Extra High Tension) faults. The gutter, which must catch uncharged drops cleanly, loses efficiency if its entrance is partially obstructed.

The 43S service manual recommends weekly printhead cleaning as standard — more frequently in dusty or high-particulate environments, and less frequently in exceptionally clean conditions. The air filter should be inspected approximately weekly (every 168 hours of continuous operation), with that interval shortened if environmental conditions are poor.

The Nozzle Flush: Your First Line of Maintenance

The nozzle flush is a software-driven cleaning function built into the Videojet 43S system menu. It’s the quickest and least invasive cleaning action available, and it should be the first response to any print quality degradation or the first step in a routine maintenance clean before opening the printhead physically.

How the Nozzle Flush Works

When a nozzle flush is initiated, the printer routes cleaning solvent through the nozzle circuit under controlled pressure, flushing residual ink and light deposits from the nozzle bore, the feed path, and the associated tubing. Unlike manual cleaning, this happens with the ink system active and requires no printhead disassembly.

Step-by-Step Nozzle Flush Procedure

Step 1 — Prepare the printhead for flushing. Before initiating the flush from the menu, loosen the knurled screw on top of the printhead and remove the front printhead cover. Place a clean container or absorbent lint-free cloth directly underneath the printhead to catch any surplus solvent that drains during the flush. This is important — without a catch container in place, cleaning solvent will drip onto the production line or the floor below.

Step 2 — Initiate the flush from the System menu. Navigate to the System menu on the 43S display and select Nozzle Flush, then press Enter to confirm. The flush sequence will begin immediately.

Step 3 — Monitor the flush cycle. The flush runs for up to 2 minutes. During this time, solvent is pushed through the nozzle circuit. You can abort the flush at any point by pressing F1 (Abort Flush) if needed — for example, if the container fills or if the flush completes visually before the timer expires.

Step 4 — Inspect and dry. After the flush completes, inspect the nozzle face and printhead interior for any remaining deposits. Use a lint-free swab to gently remove any visible residue that the flush has loosened but not fully expelled. Allow the printhead to air dry for at least a minute before reinstalling the cover and restarting the jet.

Step 5 — Reinstall the cover and restart normally. Refit the printhead front cover and tighten the knurled screw. Start the jet from the main interface and observe print quality on the next test print.

A nozzle flush takes roughly five minutes from start to finish and should be part of every weekly maintenance routine regardless of whether problems are evident. Catching minor deposits before they harden is far more effective than trying to clean baked-on ink residue later.

Manual Printhead Cleaning: The Full Procedure

When a nozzle flush alone isn’t sufficient — or during a scheduled deep clean — manual printhead cleaning provides direct access to all the critical surfaces inside the printhead cavity. This is the procedure to use when print quality issues persist after a flush, after an extended shutdown, or as part of a monthly or quarterly thorough service.

Tools and Materials

• Compatible Videojet cleaning solution (matched to the installed ink — do not substitute)
• Lint-free swabs or cotton buds (non-fibrous tip preferred)
• Lint-free cloths or tissues
• Small container or maintenance tray for solvent catch
• Protective gloves and eye protection

Printhead Components to Clean

The 43S printhead cavity contains four critical surfaces that must be inspected and cleaned during every manual service:

Nozzle orifice — The exit point of the ink jet. Inspect the front face of the nozzle for dried ink deposits around the opening. Even a small asymmetric deposit on one side of the orifice deflects the jet off its intended axis and degrades print quality.

Charge tunnel (charge electrode) — The slotted electrode assembly that applies an electrical charge to each ink droplet as it passes through. Ink bridging across the slot is a frequent cause of EHT faults and charging errors. This component requires careful attention — the slot must be completely clear and dry before the machine is restarted.

Deflection plates — The high-voltage plates that deflect charged droplets toward the substrate. Ink contamination on the deflection plate surfaces reduces the effective voltage and can cause intermittent arcing, which the printer detects as a high-voltage (EHT) trip fault.

Gutter entrance and gutter tube — The collection channel for uncharged drops. Ink accumulation around the gutter entrance restricts the opening and reduces recovery efficiency, which can lead to gutter fault alarms and recovery failure as discussed in other maintenance guides.

Cleaning Procedure

Step 1 — Stop the jet and allow a full shutdown. Initiate a normal jet stop from the main interface and allow the machine to complete its full shutdown sequence. Do not power off abruptly by cutting the mains — the 43S shutdown sequence performs an internal clean stop that draws ink back from the printhead, and skipping this leaves more residual ink in the printhead to dry.

Step 2 — Open the printhead. Loosen the knurled screw on top of the printhead and carefully remove the front cover. Place a maintenance tray or absorbent cloth underneath to catch any drips.

Step 3 — Visually inspect all surfaces. Before applying any cleaning solution, take a moment to inspect the nozzle orifice, charge electrode, deflection plates, and gutter entrance under good lighting. Identifying where deposits are concentrated helps focus the cleaning effort.

Step 4 — Clean the charge electrode. Apply a small amount of cleaning solution to a lint-free swab and gently clean the charge electrode, paying particular attention to the slot. Do not force the swab into the slot — instead, dampen it lightly and draw it across the slot opening to lift deposits. Ensure the slot is completely clear and use a dry swab to remove any remaining solvent before moving to the next surface. A wet charge electrode can cause an EHT fault on restart even if it’s visually clean.

Step 5 — Clean the deflection plates. Dampen a fresh swab and clean the contoured surfaces of both deflection plates, removing any ink film or splatter. Pay attention to the lower edges where ink tends to pool. Dry thoroughly with a clean swab — moisture on the deflection plates at restart will trigger an EHT fault.

Step 6 — Clean the nozzle face. Apply a small amount of cleaning solution to a lint-free cloth and gently wipe the face of the nozzle, working from the centre outward. Do not apply pressure directly into the nozzle orifice — the goal is to remove surface deposits around the orifice, not to push cleaning fluid into the ink system under manual pressure.

Step 7 — Clean the gutter entrance. Use a dampened swab to clean around the gutter opening and the gutter tube entrance, removing any ink accumulation. Check that the opening is fully clear and unobstructed.

Step 8 — Allow to dry completely. This step is non-negotiable. All cleaned surfaces — particularly the charge electrode slot and deflection plates — must be completely dry before the cover is refitted and the machine restarted. Even a small amount of cleaning solution bridging the charge electrode can cause an immediate EHT fault on startup. Allow at least 2–3 minutes of air drying, and use a dry swab to check for any remaining moisture.

Step 9 — Refit the printhead cover. Refit the front printhead cover and tighten the knurled screw. Do not overtighten — the printhead cover seating on the 43S is designed for a snug fit, not torque.

Step 10 — Restart and verify print quality. Start the jet normally from the main interface, allow it to stabilise, and verify print quality on a test substrate. Check that the character formation is clean and consistent across all print positions.

Cleaning the Air Filter

The 43S air filter protects the ink system and electronics from airborne particulates. Unlike the printhead cleaning tasks, this is an inspection rather than a wash — the filter is examined for contamination and replaced when saturated.

The service manual recommends inspecting the air filter approximately weekly (every 168 operating hours), with more frequent checks in high-dust environments. A clogged air filter restricts airflow through the cabinet, which over time contributes to elevated internal temperatures and can affect viscosity regulation.

The filter housing is accessible from the cabinet exterior. Remove the filter element, hold it up to a light source, and assess whether the filter media is visibly loaded with dust or particulate. Replace when the filter medium is noticeably grey or black — do not attempt to clean and reuse disposable filter elements.

Main Ink Filter: Scheduled Replacement

While not a cleaning task in the traditional sense, the main ink filter replacement is closely linked to system hygiene and should be part of any comprehensive maintenance programme. The Videojet 43S service manual recommends a main ink filter change interval of 6 months (approximately 4,368 continuous operating hours) for a new filter under normal conditions.

The ink filter sits in the ink circuit between the mixer tank and the printhead, capturing particulates from the ink before they can reach and block the nozzle. A partially saturated filter creates elevated pressure differential across the ink circuit — the pump has to work harder to maintain the correct ink pressure at the nozzle — which can manifest as erratic pressure readings, viscosity fluctuations, or in severe cases, nozzle-related faults.

Combining a main filter replacement with a full system clean is best practice. Refer to the system menu’s filter timer to check remaining hours before the next recommended change.

What Happens When Cleaning Is Neglected

Understanding the failure modes that develop from inadequate cleaning helps prioritise maintenance correctly.

EHT / High Voltage Faults — Ink contamination on the charge electrode or deflection plates is one of the most common causes of EHT (Extra High Tension) faults on the 43S. The printer detects unexpected voltage behaviour caused by ink bridging or surface contamination and raises the alarm. Regular cleaning of these surfaces directly prevents this fault category.

Gutter Faults and Recovery Failure — Ink accumulation around the gutter entrance progressively restricts the recovery opening. The printer detects reduced ink flow in the return circuit and raises a gutter or recovery fault. This fault stops the jet entirely and cannot be cleared without addressing the physical blockage.

Degraded Print Quality — Partial nozzle contamination doesn’t always generate a fault immediately. Instead, the jet deviates slightly from its optimal trajectory, producing character distortion, inconsistent dot placement, or missing dots in specific print positions. In production environments with regulatory coding requirements, this kind of subtle degradation creates compliance risk before it produces an obvious machine fault.

Nozzle Blockage — Severe, long-term neglect of nozzle cleaning allows dried ink deposits to harden inside the nozzle bore to the point where a nozzle flush cannot clear them. At this stage, nozzle removal and manual cleaning or replacement becomes necessary — a significantly more involved procedure than routine weekly maintenance.

Comparison: Nozzle Flush vs. Manual Printhead Cleaning

Both procedures are complementary — the weekly nozzle flush keeps the ink circuit flowing cleanly between manual cleans, while the manual clean addresses the electrostatic components that the automated flush cannot reach.

Industry Applications

The Videojet 43S has served across a broad range of industrial coding applications over its product lifespan:

• Food and beverage — Date coding on glass bottles, plastic containers, cans, and flexible film packaging, where ink adhesion and character legibility are subject to regulatory requirements.
• Pharmaceutical and nutraceutical — Lot coding and serialisation on bottles, blister packs, and cartons, where coding accuracy is part of product traceability and recall management frameworks.
• Cable and wire — Continuous coding along cable runs during extrusion, requiring consistent, high-speed marking on moving substrates.
• Cosmetics and personal care — Best-before dating and batch identification on packaging lines with high throughput.

In all of these environments, a poorly maintained printhead is a production risk — and in regulated industries, an audit risk. The cleaning procedures described in this article are the practical foundation of keeping that risk managed.

Maintenance Schedule Summary

• Daily: Visually inspect the printhead at startup and shutdown for obvious contamination or ink drips. Check ink and make-up solvent levels.
• Weekly: Run a nozzle flush. Inspect the air filter. Log any print quality observations.
• Monthly: Perform a full manual printhead clean covering the charge electrode, deflection plates, nozzle face, and gutter entrance.
• Every 6 months: Replace the main ink filter. Review the service menu for any maintenance hour counters approaching their recommended intervals.
• As needed: Run a nozzle flush or manual clean any time print quality degrades, after an unplanned shutdown, or before resuming operation after an extended idle period.

Conclusion

The Videojet 43S is a durable, capable CIJ printer that rewards consistent, methodical maintenance. Its built-in nozzle flush function handles routine weekly hygiene efficiently, while periodic manual cleaning of the printhead’s electrostatic components prevents the fault categories — EHT trips, gutter failures, and nozzle blockages — that cause unplanned production stoppages.

Neither procedure requires specialist tools or advanced technical knowledge. What they require is discipline: a consistent schedule, the right cleaning solution, and the patience to let surfaces dry completely before restarting. Teams that build these habits into their production workflow keep the 43S running cleanly for years. Those who skip cleaning until problems emerge find themselves dealing with faults that take significantly longer to resolve than the maintenance would have taken to prevent.

Frequently Asked Questions

Q: How do I know when a nozzle flush alone isn’t enough and a full manual clean is needed? If print quality doesn’t improve after one or two nozzle flushes, or if the machine is generating EHT faults or gutter alarms that don’t clear after a flush, manual cleaning is the next step. The nozzle flush only addresses the ink circuit — it cannot clean the charge electrode or deflection plates, which are the surfaces most likely to cause these specific fault types.

Q: Can I use make-up solvent (top-up fluid) instead of cleaning solution for manual cleaning? Make-up solvent and cleaning solution are different formulations. Make-up is designed to dilute ink viscosity, while cleaning solution is formulated to dissolve dried ink deposits. Using make-up solvent for manual cleaning is less effective, may not fully dissolve hardened deposits, and in some ink systems can cause undesired dilution effects if it enters the ink circuit. Always use the correct cleaning solution for manual cleaning tasks.

Q: The machine keeps reporting an EHT fault immediately after cleaning. What’s most likely wrong? Almost always, this means moisture from the cleaning solution is still present on the charge electrode or deflection plates. Even a small amount of cleaning fluid bridging the charge electrode slot is enough to trigger this fault. Allow more drying time — at least 3–5 minutes — and use a dry lint-free swab to check both surfaces before restarting. Blowing very gently with a clean, dry bulb syringe (not compressed air) can speed drying in the charge electrode slot.

Q: How often should the printhead be cleaned if the machine is running 24/7 in a dusty environment? In continuous high-particulate environments, the weekly manual clean schedule should be tightened to every 2–3 days. Running a nozzle flush at the start of each shift is also advisable. Check the air filter every 2–3 days rather than weekly, as it will load much faster. The key indicator is print quality — if characters start showing missing dots or distortion before the next scheduled clean, shorten the interval.

Q: Is it safe to clean the printhead while the ink system is still warm from operation? Yes — it’s actually preferable. A warm ink system has lower viscosity, meaning residual ink in the printhead cavity is less viscous and easier to dissolve with cleaning solution. The main safety precaution is ensuring the jet has fully stopped and the machine has completed its shutdown sequence before opening the printhead cover, to avoid any pressurised ink spray.