PageWide Ink Technology
September 5th, 2017
HP PageWide XL technology takes certain printing elements to new heights that other leading large format printing competitors do not offer. With PageWide XL technology, everything from high print quality to high printing speeds to economical print production are a few of the intricate details that HP has focused on improving. Using HP PageWide XL Printheads and HP PageWide XL Pigment Ink, users can meet the most demanding requirements for blue prints, CAD drawings, drafts, and more. In this post, some key variable terms and what HP PageWide XL technology aims for all users.
HP pigment ink has historically supported high-performance printing solutions across a full range of markets and applications. As industry applications and users' expectations continue to evolve, the solutions required need to follow suit in evolving as well. HP pigment ink has done an ongoing wonderful job in evolving in quality, productivity, reliability, and economically. As HP continues to evolve their ink products, how is the process done?
Chemists on HP's ink R&D teams work closely with HP color scientists and engineers to precisely develop printheads, writing systems, ink delivery systems, and the paper to be used for output. As a team working together, these teams manage the design decisions and trade-offs required for the best system-level solution.
What is an Inkjet?
Inkjets can best be described as a "colorless ink vehicle" that carries a colorant to the surface of the paper or media being used to print. This ink vehicle is important to the stability of the ink, the process of drop ejection, maintaining a reliable printhead process, and ultimately controlling the behavior of the ink on the paper's surface.
During the process, volatile components of the colorless ink vehicle are absorbed and evaporated leaving behind a layer of colorant and solids that slowly build together the printed image and provides durability.
What are colorants?
Colorants are made up of elements consisting of dyes, pigments, and sometimes a mixture of both. Colorants work by absorbing specific wavelengths of light and reflecting others. When choosing a colorant, a significant effect on color quality, drop ejection reliability, ink cost, and environmental consideration are elements to consider.
What are dyes?
Dyes are chemical molecules that dissolve within the ink vehicle. Dyes can have high color strengths and if the dyes remain at or near the paper's surface, dyes can be more colorful than pigments. However on certain media such as absorbent papers, dyes can be carried by the ink vehicle deep into the paper structure. When this occurs, there may not be enough dye near the surface to produce dense black and saturated colors.
Dyes of high concentration can counteract this effect but the result can be a beginning phase of unreliable drop ejection that will require frequent service cycles. With frequent service cycles means a reduction in productivity and an increase in the amount of ink used in servicing. For PageWide XL printing, this is an important issue that has been examined in depth with special attention being set on failed nozzles possibly leaving visible streaks down prints.
Dye-based inks offer quite a few amenities while also maintaining its fair share of roadblocks. Dye-based inks can offer excellent color performance with improved durability on more expensive inkjet coated papers. Unfortunately dyes lack a few well desired elements such as water-resistance, highlighter-resistance, and display permanence (fade resistance).
What are pigments?
Pigments are tiny particles that are on the order of 100 nanometers in diameter. Unlike most dyes, pigments do not dissolve in the ink. Pigments are kept in a stable dispersion by the ink vehicle and surface changes that produce repulsive forces between particles.
Once pigments are on paper, the chemistry of HP pigment inks quickly immobilize particles on or near the paper surface as the ink vehicle is absorbed and evaporates. This allows HP pigment inks to produce high color saturation and high black optical density as well as control color bleed, feathering, and show-through.
Reliable and robust operation
In order to achieve high productivity, inkjet printheads must be both reliable and robust. Reliable operation means that the printhead produces drops on-demand, and each drop must meet image quality specifications that are based on weight, trajectory, and speed. Reliability also means that printing hardware will see a long operating life with low operational failure rates.
PageWide XL printheads require more reliability than scanning printheads because they must produce high-quality output in a single pass. In this single pass, the printheads must achieve perfection. PageWide XL hardware does not have multi-pass print modes to hide nozzle errors. High-speed drop detection systems that test 1000's of nozzles per second can find weak or failed nozzles. The image processing pipeline in HP PageWide Technology Printers automatically substitutes good nozzles for failed ones to effectively hide nozzle errors.
Robust operation relates to the operational performance of the printhead. A printhead is considered robust if it ejects drops reliably over a wide range of operating conditions and duty-cycles. A printhead that can print high density area-fills at high speed is more robust than one that must slow down. Also, a printhead that requires less servicing to operate at a reliable rate is also naturally more robust than one that requires ongoing service.