From the two previous installments of the “Fabric Expert” series, we investigated the printing process, with an emphasis on dye-sublimation. In fabric printing, however, the led uv printer is merely 50 % of the imaging equation. Dependant upon the ink you’re using, you will additionally need some kind of post-printing equipment to match or complete the printing process.
For dye-sublimation, says Andy Arkin, director of integration for Next Wave Sublimation Solutions, “a printer does you no good unless you have a heat press.” Next Wave offers all of the bits of a complete digital textile printing workflow, including software, printer, ink, paper, fabrics, heat presses, and finishing equipment. They distribute transfer-based dye-sublimation printers, and are also a distributor of EFI Reggiani fabric printing equipment.
Before we take a look at heat presses, let’s back an additional and talk for a moment about transfer paper, an often overlooked but vitally important element of the dye-sublimation process.
Dye-sublimation transfer paper posesses a special coating that holds the ink laid down during printing. Through the transfer stage, under contact with heat and pressure, the paper releases that ink to the fabric. Dye-sublimation may be used on substrates aside from textiles, so you must choose your transfer paper accordingly.
“You ought to be alert to the sort of paper you’re using,” says Rob Repasi, VP of Global Sales for Beaver Paper & Graphic Media. “There are papers which are more inviting for textiles rather than hard surfaces for example ceramics, coffee mugs, or metal.”
You will find premium multipurpose papers-like Beaver Paper TexPrintXPHR-that are works with both hard and soft substrates, which is convenient if you’re offering a number of dye-sub-printed products.
The grade of the paper will largely determine the amount of ink gets released, but ink dye load is really a consideration. “Dye load” means simply how much colorant (dye) the ink contains relative to the liquid vehicle. The better the dye load, the less ink you have to lie down to get a given amount of color. Different transfer papers are thus formulated to become suitable for the dye load from the ink, which is generally a purpose of the brand name of your printer you will be using-or, that is, the t-shirt printer manufacturer’s ink set.
Ideally, a transfer paper will release 90 % in the ink “stored” inside it. There is absolutely no quantitative way to measure this, but if you discover you’re failing to get just as much ink out as you think you have to be, you might need to switch papers or adjust your color profiles. Alternatively, you may be releasing excessive ink on the fabric, which means that you might be putting a lot of ink onto the paper in the first place.
“There is a misconception of how much ink is actually needed,” says Repasi. “More ink doesn’t necessarily indicate more color. You’ll get a bad image by making use of more ink compared to the paper are prepared for.” It’s all a question of balance. “The correct amount of ink with all the right color management with all the right paper will generate the very best output of color.”
Printed transfer paper doesn’t have to be sublimated immediately. Beaver Paper’s own internal experiments have found that printed transfer paper will last for years. “We’ve transferred literally a year or so later and it’s remarkably near to the original prints,” says Repasi. It is going to naturally depend on the conditions under in which the paper is stored. Still, in today’s fast-turnaround realm of digital printing, you’ll probably never must store transfer paper for several hours, but if you want to, you may.
First a terminological note. We quite often view the term calender – not to be confused spelling-wise with calendar (despite Autocorrect’s best efforts) – used jointly with dye-sublimation printing. What’s the real difference from a calender along with a heat press?
“A calender press can be a rotating heated drum intended for feeding continuous materials for sublimating such things as banners or other long stretches or bulk fabric,” says Aaron Knight, VP of Geo Knight and Co., a manufacturer of numerous flatbed and specialty heat presses. “It’s not competent at pressing rigid materials, nor will it be suitable for doing smaller piece goods.” A calender, then, is actually a roll-to-roll heat press.
In the calender, heat is manufactured in a central drum against that your fabric and paper are pressed. The best-quality calenders have got a central drum full of oil which is heated on the desired temperature required for sublimation, typically from the neighborhood of 400°F. The transfer paper/fabric sandwich is rolled around this drum in a set rate that is, again, optimal for sublimation. A top-notch-notch oil-filled calender will run you about $30,000 to $60,000, but may last for more than twenty-five years.
There are other kinds of cheaper calenders designed to use electric heating elements as an alternative to oil, but a common downside to them is inconsistent heat around the circumference or across the width in the drum. This may cause imaging problems or discoloration during sublimation which, all things considered, is really a careful balance of time, temperature, and pressure. “If any one of those three changes, you will not possess a consistent result,” said Arkin. “Color will not turn out the way it should really. For those who have inconsistent heat on the press, the sublimation process is definitely not consistent across the entire part of fabric.”
Calenders have different width drums, which modify the press’s throughput. The greater the diameter from the drum, the greater number of fabric could be wrapped around it, and therefore the faster the method will be.
Calenders transfer the fabric and transfer paper with a belt often made of Nomex. “The belt is actually a critical section of the nice tight sandwich you need round the circumference in the drum,” says Arkin. “Cheaper machines have very thin belts, while good machines have belts that happen to be one-half to inch to 3-quarters of your inch thick. Whether it doesn’t stay nice flat, sublimation gases can escape.” A high-quality belt may last approximately five or six years. You will find beltless calenders that are compatible with direct-to-fabric dye-sublimation, the place you don’t need to worry about transfer paper.
If you’re not sublimating rolls of fabric but rather cut pieces, the alternative to a calender is a flatbed heat press. Flatbeds also come in several varieties:
A clamshell opens and closes like its namesake, squeezing the paper and fabric together.
Over a swing-away press, the upper platen, which supports the heating element, slides away left or right, rendering it considerably better than the usual clamshell for thicker substrates.
A drawer press carries a front-loading lower platen that, if the fabric and paper are loaded, slides back in place as well as the heating element is brought down along with it. Additionally, there are specialty heat presses that could accommodate things such as mugs, plates, caps, and other three-dimensional objects.
Typically, a computerized timer can pop the press open after a desired transfer time and energy to prevent overheating, especially if an operator is attending to multiple presses.
There are newer “all over sublimation” flatbed heat presses with heating elements on both the very best and bottom that essentially “duplex” dye-sub transfer, which is wonderful for applying continuous graphics to both sides of, say, a T-shirt.
In relation to deciding on a flatbed press, says Knight, “the product an individual is printing, along with the volume they can be doing, will dictate which of the choices is appropriate. Also, how big the goods they can be printing will direct them towards a couple of narrowed-down selections for heat presses.”
If you work with a flatbed heat press, you may need to use “tack” transfer paper, which contains an adhesive applied that, when activated by heat, keeps the paper in contact with the material so there is no shifting during the sublimation process, which can cause blurring or ghosting. Tack paper isn’t usually required if you are by using a roll-to-roll heat press, except if you’re sublimating onto an incredibly elastic fabric which could stretch because it moves throughout the calender, causing a distorted image if it relaxes after cooling.
In case you are sublimating to highly stretchy fabric, you may need to make amends for stretch even before printing. “You establish precisely what the shrink or stretch is perfect for a given material, so you build those distortions into your files when you print them,” says Arkin. “Every time you handle that specific fabric type, you print it the same way so you get a consistent result.” It’s kind of like color profiling, in such a way.
Even when you are doing direct-to-fabric rather than transfer-based dye-sublimation, you will still should run the printed fabric using a calender to correct the ink into the fibers of your polyester, along with the same quality and consistency concerns apply.
Even though you’re printing with other sorts of dye or pigment inks – not sublimation -you will still need some kind of pre- and post-treatments for the material. Reactive and acid dye inks require steaming after printing, then washing to remove excess ink. This is one explanation why dye-sublimation is really attractive for fabric printing; these dexjpky05 ink types can require a lot of water.
Irrespective of the specific configuration of heat press, you don’t would like to skimp on quality. “Look for same-day support and longevity; in a word, quality,” says Knight. “In the machine world, particularly with heat presses that reach high temperatures and pressures, you will need the one that may last decades, not simply months or many years. A A4 UV Printer will give you quality results and builds your company – an unsatisfactory press puts you of business.”
“The right heat press is exactly what separates from being able to produce an okay graphic vs. an excellent graphic,” says Arkin.
Next month, in the fourth installment of this series, we will check out the finishing process: sewing, welding, along with a fast-growing form of fabric finishing, specifically for signage, silicone-edge graphics.