Whether you laminate application tape by hand or with a laminator, avoid trapping air bubbles between the vinyl graphics and the application tape. Bubbles and wrinkles in the application paper often result in bubbles and wrinkles in the applied graphic, regardless of the skill and effort of the installer. If you inspect the adhesive side of a graphic, after removing the release liner, you often can see the formation of wrinkles and bubbles in the adhesive. In the application process, you will just transfer these wrinkles and bubbles to the substrate.
HP Launches New Latex 300 Series Printers
In 2014 HP launched the 300 series of latex printers. The new models include the 54” HP Latex 310 Printer, the 64” HP Latex 330 Printer and the 64” HP Latex 360 Printer. All three models use the new 831 HP latex inks, which provide outstanding resistance to scratching. This third generation of latex printers represents a radical departure from the precedent technology.
“Forget everything that you had previously learned about latex inks,” says Timothy Mitchell, Latex Experience Solutions Architect. “The new 300 series is completely different from earlier generations of HP latex printers. With the addition of the HP Latex Optimizer and an anti-scratch agent, the new HP831 inks are different. The design of the printheads is different. And the curing system of the printers is different. We have also made many other improvements to the design of the printers, to make them more user-friendly and more reliable.”
HP had introduced its first generation of latex printers in 2008 as a water-based alternative to solvent and ecosolvent printers. With more than 15,000 printers shipped worldwide in the last six years, HP latex printers have rapidly grown in popularity, as the sales of solvent and ecosolvent printers have declined by 33%.
Latex versus Solvent
Latex ink really is eco-friendly, unlike solvent ink or even the so-called ecosolvent ink. Ecosolvent inks are neither economical, nor are they eco-friendly. Ecosolvent inks may not have the overpowering smell of standard solvent inks, but the solvents are still there. And for that reason, they should be vented to outside air.
But because latex inks are water-based, you have none of the hazards of solvent inks. There’s no obnoxious solvent odor. No dangerous VOCs to pollute the great outdoors or the environment inside your shop. The advantages are that there is no need for a special ventilation system and no hazardous waste is produced.
What’s more, when compared to printing with solvent-based inks, to co-opt a Johnny Bench expression, “your graphics won’t stink”. No solvents in the ink mean no obnoxious solvent smell emitting from printed graphics. That’s important when producing wall graphics and customized wallpaper used in stores, restaurants, schools and homes.
Residual solvents in printed graphics not only smell, but they can also migrate through a film facestock into the adhesive. These latent solvents can compromise the adhesive bond to the substrate resulting in edge curl.
The HP latex inks provide many of the same benefits of solvent inks. Because the inks are water based, there are none of the problems associated with solvent inks. There is no solvent smell, no hazardous waste, negligible VOCs, and no residual solvents to degrade adhesive performance. Latex inks are also more scratch resistant than ecosolvent inks. And when cured properly, the inks are completely dry and ready to be laminated.
The latex inks consist of a liquid vehicle, which is primarily but not entirely water, pigments and microscopic latex polymer particles, which act as the binder. Latex inks are also durable. While most people associate dyes with water-based inks, the HP inks are different. These latex inks are pigmented. So they are perfect for commercial applications, such as outdoor signage and billboards. Mitchell explains that the new latex printers also allow sign makers to print on a wider range of sign substrates, including Point-Of-Purchase posters, light box transparencies, outdoor banners, vehicle wrap graphics, wall coverings and canvas.
“The versatility of the new HP 300 series opens the doors for sign shop owners to many new sales opportunities,” says Mitchell. “For critical applications that are viewed at a short distance, such as Point-Of-Purchase posters or backlit transparencies, our new printers can produce high-resolution prints up to 1200 dpi. The color gamut for the latex inks is certainly equal to or better than any of the ecosolvent or low-solvent inks on the market. And for demanding outdoor applications, our new scratch-resistant inks are durable enough to weather harsh environments, yet flexible enough to allow vinyl graphics to conform to complex surfaces, including rivets and corrugations.”
The printheads for the 300 series of printers have been improved for more consistent performance. In a typical thermal printhead, the orifice through which the ink is ejected increases in size over time as the printhead heats up. As the size of the orifice increases, so does the size of the ink droplet. When this happens, color frequently varies from one print to another.
The new six-color HP thermal printheads maintain much more consistent temperatures. The result is more consistent color, which is especially important, when printing large graphics, such as vehicle graphics or wall graphics, involving multiple panels. Panel to panel match in these applications is absolutely critical, especially when there are multiple points of alignment in the design.
The ink supply station holds six different colors plus the Latex Optimizer. Each ink cartridge has a capacity of 775 ml and is easily replaced, when the printhead is docked in the maintenance station.
The 54” 310 and the 64” 330 printers are positioned as entry-level machines. Their compact design is ideal for smaller sign shops with limited floor space. Both printers are versatile enough to print on a wide array of substrates from vinyl banners to pressure sensitive films.
Both the 310 and 330 models are bundled with SA International (SAi) FlexiPRINT Raster Image Processor (RIP) software. To accelerate a novice printer’s learning curve, the FlexiPRINT Basic Edition software features a Print Wizard with tools for scaling and rotating, interactive and automated tiling, nesting and color management. All of the 300 series printers also allow for automatic downloading of media profiles from HP’s cloud based library of profiles.
The 64” HP360 is 40% faster than the 310 or the 330 because the carriage travels at a faster speed. The curing system is also more powerful, which contributes to the increased speed. The maximum print speed for the HP360 is 980 ft²/hr (91 m²/hr) versus a maximum speed 517 ft²/hr (48 m²/hr) for the HP310 and 538 ft²/hr (50 m²/hr) for the HP330.
The HP360 also allows for automatic double-sided printing, and incorporates a cutter on the printhead carriage. An Optical Media Advance Sensor (or OMAS) is another feature only available on the HP 360. At high print speeds, accurate media advance is critical in producing a high quality print. By taking continuous readings as the media is printed, the system automatically adjusts the advance or movement of the printed material. These adjustments are key in preventing banding in the printed image. This sensor also allows for precise registration of the media, when printing a double-sided job.
The HP360 also allows the operator to quickly and easily replace the standard print platen with an ink collector. This enables printing on highly porous media, such as mesh material and textiles. When printing on these substrates, the ink that goes through the media is absorbed by the foam inside of the ink collector. That way the printer stays neat and clean. Using the ink collector also allows the operator to print full bleeds.
All three printers are designed to satisfy the needs of sign makers for an affordably priced printer, which can produce a print durable enough to withstand the rigors of outdoor applications and high quality enough for indoor applications.
“Many people have the misconception that latex prints are not as durable as ecosolvent and solvent printing,” Mitchell says. “That wasn’t true with our first generations of latex inks. And it certainly isn’t the case with our new optimized inks.”
The HP latex inks are engineered to embed onto the surface of the substrate. Good adhesion and robust pigments allow the ink to withstand the elements. Neither snow nor rain nor heat nor gloom of night…well, you get the idea. These inks were specifically formulated to meet or exceed the demanding requirements of the billboard and sign industries.
Latex inks are ideal for exterior applications such as outdoor advertising, banners, transit advertising and vinyl lettering and graphics on signs and vehicles. The latex inks and HP new line of printers are also suitable to print high resolution prints with vibrant colors of indoor applications such as Point-Of-Purchase displays, wall graphics, tradeshow graphics and museum graphics.
HP Latex Optimizer
What’s different about the inks used in the new latex printers is the additional of the HP Latex Optimizer. The polymers of the Latex Optimizer interact with the pigments in the ink. First a thin coating of optimizer polymer is printed onto the substrate. Then the inks are printed on top of this layer. Because the ink and optimizer have different electrical charges, they are attracted to one another. This locks the droplets of ink onto the substrate, holding it in place until it is cured. This prevents one droplet of ink from mixing with another or what is called bleed or coalescence. Because the dots don’t coalesce or bleed together, colors are more vibrant rather than becoming dark and muddy.
Another improvement is the addition of an anti-scratch agent in the ink. This anti-scratch agent forms a very thin, protective film on the surface of the print. The coating also greatly improves scratch resistance and the outdoor durability of the print. By comparison, ecosolvent inks scratch very easily. You can very easily demonstrate the improved scratch resistance of the new latex inks versus the ecosolvent inks by performing a thumbnail test. (This is a simple test in which you rub your thumbnail over the printed image.)
Now this may sound like a contradiction. While the optimizer hardens the ink making it more scratch resistant and providing for a longer service life, it does not stiffen the media. The printed ink is very flexible, which makes it ideal for fleet graphics and vehicle wrap applications. The ink allows for the vinyl to be stretched over rivets and into concave indentations on the vehicle surface.
HP claims that the new latex inks provide three years of outdoor durability with no clear coating or overlaminate. Of course, extra protection always helps. Protected with an overlaminate, durability of the latex inks should be extended to five years of useful outdoor life.
High-Efficiency Curing System
The HP 300 series also features their high-efficiency curing system, which utilizes forced hot to dry the media at a much faster speed and requires less energy. Reduced exposure to high temperatures allows for printing on heat sensitive materials.
Here’s how the high efficiency curing system works. The heart of the system is the curing module. Inside the module hot air is circulated and blown through hundreds of tiny nozzles onto the print media. The micro-jets of hot air are hot enough to cure the ink but not so hot as to deform or damage the substrate.
Because prints are subjected to heat for a shorter period of time, it allows you to print heat-sensitive materials such as low cost banner media, polyesters and polypropylenes. Prints come off of the printer completely dry and ready for lamination.
Another improvement is that the curing system requires a much shorter time to warm up. In fewer than two minutes the printer is ready to print.
User Friendly Features
The new HP latex 300 series is also designed with simplicity in mind. A new, color touchscreen user interface is very similar in appearance and functionality to the touchscreens used on smart phones and i-pads. This front panel allows the operator to control printer operation, displays printer status and stores substrate presets.
The software is also much more intuitive. Operators do not need special training. Nor do they need to read a manual as thick as a phonebook to use the printer. If an operator requires additional information, instructions and animations are conveniently displayed on the front panel. For additional instruction, QR codes on the control panel link to videos, which an operator can access on a smart phone.
The new HP printers are also web connected so a user can easily download free software upgrades and media profiles. The ability to locate and download stock profiles from the HP library allows operators to print on popular media, without making time-consuming tweaks or making special profiles. Of course, each printing environment and project is different, so the stock profiles can be modified as needed. The user can adjust the ink deposit, the number of passes and temperature settings. The HP media profiles are also universal, so they are compatible with any RIP.
Color management for the new 300 series printers has also been simplified. While you can still manage color from the RIP, the printer can automatically monitor the ink printed and make a necessary correction, which ensures color consistency from one print to the next.
The 310 and 330 printers feature an embedded densitometer. The 360 model includes an embedded spectrophotometer. Both the densitometer and the spectrophotometer are color sensors, which scan the color calibration pattern so the printer can automatically make any necessary adjustments. But the spectrophotometer also allows the user to generate an ICC profile. That provides the printer with the capability of exactly matching colors. If a shop has a number of printers, each can be calibrated to a specific color target. That way, each printer is printing the same color.
To facilitate handling of the heavy rolls of media, the 300 series of printers allow for convenient front loading. Since there is no reason to go to the backside of the machine, you can position the printer up against a wall, which saves valuable floor space.
The new HP latex printers also come standard with media edge holders. These edge holders, which are also referred to as media clips, are designed to prevent the edges of the media from lifting up, while you are printing so you don’t get head strikes. What a great feature! These holders are particularly helpful when printing on a substrate that tends to deform, such as polycarbonate film.
Although HP offers a variety of print media compatible with their latex inks, the HP latex printers are capable of printing on a much broader range of products. The HP line of media includes photo paper, a wide range of banner material and films for backlit displays.
The new HP 831 latex inks also allow for printing on a diverse range of uncoated media, such as pressure sensitive vinyl, polyurethane heat transfer films and polycarbonate films. HP has certified many different substrates from several recognized media suppliers. A comprehensive list of latex compatible media in their Media Certification Program is listed on the HP website at hp.com/go/mediasolutionslocator.
Sign makers have good reason to be excited about the new HP Latex 300 series. With the advances in latex ink technology you get the best of both worlds: high quality printing for indoor applications, plus outdoor durability to withstand the blistering heat and bleaching UV sunlight of summer weather.
Equipment improvements have also made the new HP printers faster, more reliable and easier to use. The simplified touchscreen controls and downloadable updates and profiles save countless hours of production time.
“The throughput of the 300 series is great. It is much faster than many other printers in its price range,” says Timothy Mitchell. “The image quality is outstanding, which can allow sign makers to print high quality interior graphics and Point-Of-Purchase posters. And for outdoor signage the printers provide full service sign shops with the versatility and durability to produce an array of signage from banners to vehicle wraps.”
This article was written by Jim Hingst, Business Development Manager-Technology for RTape Corp. and posted on Hingst Sign Post.