Behold the large-format digital printer. It’s one of the most heavily invested and relied upon pieces of equipment in your shop. And while your printer may be seem to be your greatest and most profitable ally, prolonged neglect can cause your printer to go down and quickly morph into your most dreaded and costly evil arch-nemesis.
When the printer is down, production stops, yet jobs continue to roll in. This disruption of your shop’s workflow can quickly snowball into an array of production concerns, all of which are in direct conflict with client demands. And while occasional hiccups and support calls are inevitable, many common tech calls can be avoided by practicing a thorough and regular preventive maintenance regimen designed to keep your printer healthy and happy—and the profits to keep rolling in.
When developing a preventive maintenance regimen, the owner’s manual that came with your printer serves as an excellent starting point. Most manufacturers provide specific maintenance schedules for each model in their lineup that outlines recommended daily, weekly, monthly, and yearly maintenance procedures. The guidelines offered in this article are fairly general and may not be appropriate for all machines. Follow manufacturer’s recommendations closely, they will be the most relevant and accurate your specific machine.
Manufacturer’s websites can also be a wealth of information. For example, EFI offers extensive maintenance documentation on its website (w3.efi.com) for its entire line of VUTEk printers, including a section for each called Best Practice Ink Purging Tips and Tricks.
The Maintenance Kit
It’s important that your shop keep certain items on hand to ensure your printers receive adequate care and remain well maintained. *NOTE: Consult with your supplier or manufacturer, as some models may require specific maintenance products (maintenance fluids, cleaning cloths, etc.) to prevent damage to the printheads and other integral components of the machine. The following items are universal and provide a solid foundation:
Lint-Free Cloths & Cleaning Swabs—Printer cleanliness plays a crucial role in effective printer maintenance. Lint-free cloths and cleaning swabs are great for cleaning printheads (when applicable) and other sensitive areas where dust accumulation and ink buildup are problematic, such as the wiper, capping station, or platen.
Maintenance Fluid & Isopropyl Alcohol—Use the appropriate maintenance fluid when maintaining the more sensitive parts of your machine (e.g. parts that come in contact with the printhead). Isopropyl alcohol, a staple supply in most every sign shop, can be used to clean the remaining parts of your printer.
Latex Gloves, Ventilation Mask, and Safety Goggles—Performing printer maintenance can be a dirty job, so keep your hands clean and ink-free with protective gloves. You may also want to wear a ventilation mask and safety goggles to avoid harmful fumes and splattering ink.
3-IN-ONE Oil—Used as a general lubricant for carriage rails and other moving parts.
Various Tools—You will likely need some tools to access certain components of your machine. These may include a set of Allen wrenches (the t-handle sets are great) and screwdrivers with magnetic tips to prevent screw loss in tight areas.
Spare Printer Parts—To prevent costly downtime, keep certain consumables on hand in the event that something needs to be replaced. These may include wipers, media cutting blades, dampers, ink filters, UV lamp filters, etc. Reorder when necessary to maintain a solid inventory of these important items.
Consider keeping the items in your maintenance kit in one area to allow for quick visual inventory checks. If necessary, keep an inventory checklist to avoid any surprises and reorder supplies as needed. If you have more than one printer, be sure to label replacement parts for easy reference.
Maintenance Basics: Creating a Schedule
Implementing a preventive maintenance regimen requires discipline and consistency, a daily and weekly ritual of sorts. On a daily basis, perform the necessary head cleanings and print nozzle checks to make certain all of your nozzles are firing. This will provide a frequent glimpse into printhead health, allowing you to take notice and appropriate action when things start to go awry. Monitor your prints throughout the day to ensure nozzle health and perform additional cleanings as needed.
In addition to required daily maintenance, it’s also important to practice a weekly maintenance routine reserved for deeper cleaning and thorough inspection. Put it through its paces during the week, then give it a little TLC before heading off for the weekend.
Solvent & Eco-Solvent Printers
An effective preventive maintenance regimen for solvent and eco-solvent printers should include daily nozzle checks and cleanings, along with weekly inspection and/or cleaning of the following:
Printheads—In addition to performing daily nozzle checks, you should visually inspect the printheads to ensure cleanliness. Check for excess ink buildup on the carriage plate and around the perimeter of the printhead left behind from the wiping mechanism. If neglected, the ink will continue to build, causing clogged nozzles and possible contact with the media surface while printing. Use a firm cotton swab and maintenance solution to remove ink and a lint-free cloth to clean the bottom of the carriage plate. Be careful to avoid direct contact with the printhead if recommended by the manufacturer.
Wipers—Wipers play a key role in a printer’s health and performance, and are one of the most frequently replaced parts of a printer. After ink is purged through the printhead during a cleaning cycle, the wiper travels across the head, removing the excess ink. Pay close attention to your print quality and visually inspect the wiper for any defects, ink buildup, or deformities. Clean with a swab and maintenance fluid and replace when necessary (see page 55 for example of wiper cleaning of Mimaki JV33-160).
Capping Station—The capping station is where the printhead comes to rest while the printer is inactive. It is surrounded by a rubber seal that prevents the printhead from drying out. Inspect the seal for defects and remove ink buildup with a swab and maintenance fluid to ensure a tight seal.
Platen & Media Clips—Over time, the platen and media clips accumulate ink buildup, dust, and powder residue from repeated media cuts. Clean with a lint-free cloth and isopropyl alcohol.
Waste Ink Tank—Residual ink purged through the printheads during head cleanings funnels down to the waste ink tank. Monitor the tank’s ink level and empty when necessary, disposing of the ink properly. Clean the tank with isopropyl alcohol and reattach.
Pinch Rollers—Dirty pinch rollers may cause unsightly tracking marks in your prints. Overspray from the printheads can leave an invisible layer of ink on the rollers, which then transfers to the media. While this may not need to be done weekly, clean with maintenance fluid and a lint-free cloth when necessary. Allow adequate drying time after cleaning as the maintenance fluid will take longer to evaporate than isopropyl alcohol.
Some solvent and eco-solvent printers are also equipped with advanced maintenance diagnostic features (either linked with the RIP or standalone software). For example, the Seiko ColorPainter W-64s printer comes with CP Manager software that allows the operator to monitor printer status and provides step-by-step maintenance procedures.
Latex and Resin Printers
Up-and-coming latex and resin type inkjet printers have been applauded for their maintenance-friendly features. One example is the HP L26500 latex printer, which is equipped with automatic maintenance features and an embedded web server that continuously monitors the system, alerting operators when additional manual maintenance (printhead replacement, calibration, etc.) is required.
As with solvent and eco-solvent printers, general daily and weekly maintenance regarding the platen, media clips, and waste ink tank remain the same. One key difference is that HP’s latex thermal printheads are consumable and meant to be replaced more frequently, which is a very simple task. This is not the case, however, with Mimaki’s latex printers, which use unique piezo printheads.
Preventive maintenance for UV-cure printers requires daily nozzle checks and weekly inspection and/or cleaning of the following:
Printheads—The cleaning process for UV-cure printers generally requires the purging of ink (either manually or automatically) through the heads to remove any foreign debris, then wiping clean. Some models recommend using maintenance fluid when cleaning the heads, while others (such as the X-Press 500H from CET Color) suggest wiping dry with a clean lint-free cloth. Also, clean the bottom carriage plate encasing the printheads to remove any cured ink.
Carriage Rails—Check where the carriage mounts to the rail for dust buildup and use compressed air to remove. Depending on your manufacturer recommendations, lube the carriage rails monthly (I recommend 3-IN-ONE brand household oil) to ensure smooth travel for the duration of every pass.
Vacuum Table & Hybrid Belt—If your shop produces full-bleed prints, ink will inevitably find its way onto the vacuum table or hybrid belt. Over time, excess ink buildup may cause a loss of suction and/or an uneven surface, increasing the risk of printing defects and head strikes. There is a product called MiraWipes made specifically for the purpose of removing stubborn UV ink.
UV Lamps & Lamp Filters—Similar to standard light bulbs, the UV Lamps need to be replaced after so many hours of operation. Pay close attention to the quality of ink adhesion, as the curing mechanism loses effectiveness as the bulbs age. Also, check the lamp filters for cleanliness to improve lamp performance and prevent overheating.
Quartz Plate—The quartz plate of the UV cure-lamp enclosure should remain clean and clear of obstructions. This allows the maximum amount of UV light to pass through and cure the ink while printing.
Waste Ink Tank—Just as with solvent and eco-solvent printers, monitor the volume in the waste ink tank and empty when necessary, disposing of the ink properly.
Carriage Height Calibration—Because flatbed printers have the ability to print onto a wide variety of substrates, the carriage on many units will measure the height of each unique media prior to printing. Over time, this measurement may become inaccurate and affect print quality. Recalibrate the carriage height according to your printer’s manual.
White Ink—For printers with white ink capability, extra care is needed to assure the white ink continues to flow freely. In general, white ink has a higher viscosity than CMYK inks and is prone to settling. To combat this, many printers equipped with white ink have a recirculation pump installed in the white ink channel to keep the ink fresh and fluid. For example, prior to running a job with white ink, the Agfa :Anapurna M2050 recommends running a white ink circulation to breakup possible ink sediments and reintroduce them into the ink solution.
Additional Considerations for All Printers
In addition to the above recommendations for general maintenance, it’s also important to familiarize yourself with the calibration of your printers (e.g. bidirectional alignment, step calibration, nozzle alignment, etc.). If troublesome printing defects remain after thorough cleaning and maintenance, print your calibration test patterns, make the necessary adjustments, and reevaluate your print quality.
As you read these tips, it’s easy to see that practicing a preventive maintenance regimen aims to encourage the flow of ink and limit the amount of ink buildup in your printer’s system. Ink is the lifeblood of your printer, and the chance of clogged nozzles and other printing defects increases dramatically if the printer is neglected and dried ink continues to accumulate.
By implementing a smart preventive maintenance regimen, your printer will remain a healthy, happy, and dependable ally that lives up to its word of delivering profits. Happy printing!