Inside the two previous installments of our “Fabric Expert” series, we investigated the printing process, with a focus on dye-sublimation. In fabric printing, however, the uv printer is just 50 % of the imaging equation. According to the ink you’re using, you will additionally need some sort of post-printing equipment to complement 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 will have a heat press.” Next Wave offers every one of the items of a total digital textile printing workflow, including software, printer, ink, paper, fabrics, heat presses, and finishing equipment. They distribute transfer-based dye-sublimation printers, and tend to be a distributor of EFI Reggiani fabric printing equipment.
Before we look at heat presses, let’s back another and talk for a second about transfer paper, an often overlooked but extremely important element of the dye-sublimation process.
Dye-sublimation transfer paper includes a special coating that holds the ink laid down during printing. Through the transfer stage, under exposure to heat and pressure, the paper releases that ink to the fabric. Dye-sublimation can be utilized on substrates apart from textiles, so you should choose your transfer paper accordingly.
“You should be alert to the particular paper you’re using,” says Rob Repasi, VP of Global Sales for Beaver Paper & Graphic Media. “There are papers that happen to be more desirable for textiles as opposed to hard surfaces like ceramics, coffee mugs, or metal.”
There are premium multipurpose papers-like Beaver Paper TexPrintXPHR-that happen to be works with both hard and soft substrates, that is convenient if you’re offering various dye-sub-printed products.
The standard of the paper will largely determine how much of ink gets released, but ink dye load is a crucial consideration. “Dye load” describes how much colorant (dye) the ink contains in accordance with the liquid vehicle. The greater the dye load, the less ink you have to lie down to get a given amount of color. Different transfer papers are thus formulated being suitable for the dye load from the ink, which is usually a purpose of the make and model from the printer you might be using-or, which is, the garment printer manufacturer’s ink set.
Ideally, a transfer paper will release 90 percent of the ink “stored” in it. There is absolutely no quantitative method to measure this, but if you locate you’re failing to get as much ink out while you think you ought to be, you may want to switch papers or adjust your color profiles. Alternatively, you may be releasing a lot of ink to the fabric, meaning that you could be putting too much ink into the paper to begin with.
“There is really a misconception of how much ink is very needed,” says Repasi. “More ink doesn’t necessarily indicate more color. You’ll get a poor image by making use of more ink than the paper are prepared for.” It’s all a subject of balance. “The proper amount of ink with all the right color management with the right paper will generate the very best production of color.”
Printed transfer paper doesn’t must be sublimated immediately. Beaver Paper’s own internal experiments have found that printed transfer paper will last for years. “We’ve transferred literally a couple of years later and it’s remarkably near to the original prints,” says Repasi. It would needless to say rely on the conditions under which the paper is stored. Still, in today’s fast-turnaround realm of digital printing, you’ll probably never should store transfer paper even for a few hours, but if you have to, it is possible to.
First a terminological note. We often view the term calender – to never be confused spelling-wise with calendar (despite Autocorrect’s best efforts) – used jointly with dye-sublimation printing. What’s the real difference between a calender along with a heat press?
“A calender press is a rotating heated drum designed for feeding continuous materials for sublimating stuff like banners or another long stretches or bulk fabric,” says Aaron Knight, VP of Geo Knight and Co., a manufacturer of a wide variety of flatbed and specialty heat presses. “It’s not able to pressing rigid materials, nor would it be appropriate for doing smaller piece goods.” A calender, then, is a roll-to-roll heat press.
Inside a calender, heat is manufactured in a central drum against in which the fabric and paper are pressed. The very best-quality calenders use a central drum full of oil that is certainly heated on the desired temperature necessary for sublimation, typically from the neighborhood of 400°F. The transfer paper/fabric sandwich is rolled around this drum at the set rate that is, again, optimal for sublimation. A high-notch oil-filled calender will run you about $30,000 to $60,000, but will last for greater than 25 years.
There are additional types of less expensive calenders designed to use electric heating elements as an alternative to oil, but a typical downside to them is inconsistent heat round the circumference or across the width from the drum. This could cause imaging problems or discoloration during sublimation which, in the end, is really a careful balance of energy, temperature, and pressure. “If any one of those particular three changes, you simply will not have got a consistent result,” said Arkin. “Color will not appear the way it should really. If you have inconsistent heat around the press, the sublimation process will not be consistent across the entire piece of fabric.”
Calenders have different width drums, which affect the press’s throughput. The larger the diameter of your drum, the greater number of fabric can be wrapped around it, and consequently the faster the procedure is going to be.
Calenders transfer the fabric and transfer paper on a belt often manufactured from Nomex. “The belt can be a critical portion of the nice tight sandwich you want round the circumference of your drum,” says Arkin. “Cheaper machines have very thin belts, while good machines have belts that are one-half to inch to 3-quarters of the inch thick. Whether it doesn’t stay nice and flat, sublimation gases can escape.” A higher-quality belt may last around five or six years. There are actually beltless calenders that are compatible with direct-to-fabric dye-sublimation, where you don’t have to worry about transfer paper.
If you’re not sublimating rolls of fabric but alternatively cut pieces, the alternative to a calender is really a flatbed heat press. Flatbeds can be found in several varieties:
A clamshell opens and closes like its namesake, squeezing the paper and fabric together.
On the swing-away press, the upper platen, which supports the heating element, slides away on the left or right, so that it is more suitable than the usual clamshell for thicker substrates.
A drawer press features a front-loading lower platen that, once the fabric and paper are loaded, slides in place and the heating element is brought down in addition to it. Additionally, there are specialty heat presses that will accommodate stuff like mugs, plates, caps, along with other three-dimensional objects.
In many instances, an automated timer can pop the press open following a desired transfer time to prevent overheating, particularly when an operator is attending to multiple presses.
You will find 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 terms of picking a flatbed press, says Knight, “the product an individual is printing, and the volume they may be doing, will dictate which of such choices is appropriate. Also, the size of the item they may be printing will direct them towards a couple of narrowed-down choices for heat presses.”
If you work with a flatbed heat press, you may want to use “tack” transfer paper, which includes an adhesive applied that, when activated by heat, keeps the paper in touch with the material so there is no shifting during the sublimation process, which may cause blurring or ghosting. Tack paper isn’t usually required when you find yourself using a roll-to-roll heat press, except if you’re sublimating onto an incredibly elastic fabric which can stretch because it moves from the calender, causing a distorted image in the event it relaxes after cooling.
If you are sublimating to highly stretchy fabric, you might need to make up for stretch just before printing. “You establish what the shrink or stretch is designed for a particular material, and also you build those distortions in your files when you print them,” says Arkin. “Every time you handle that exact fabric type, you print it exactly the same way so you receive a consistent result.” It’s kind of like color profiling, in such a way.
Even if you are doing direct-to-fabric rather than transfer-based dye-sublimation, you still should run the printed fabric using a calender to fix the ink onto the fibers from the polyester, along with the same quality and consistency concerns apply.
Even when you’re printing with other kinds of dye or pigment inks – not sublimation -you continue to need some sort of pre- and post-therapy for the fabric. Reactive and acid dye inks require steaming after printing, then washing to take out excess ink. This is one reason why dye-sublimation is very attractive for fabric printing; these dexjpky05 ink types can require a lot of water.
Whatever the specific configuration of heat press, you don’t would like to skimp on quality. “Look for same-day support and longevity; in the word, quality,” says Knight. “In the machine world, particularly with heat presses that reach high temperatures and high pressures, you need one who lasts decades, not just months or a few years. A uv printer gives you quality results and builds your business – a negative press puts you out of business.”
“The right heat press is what separates you from having the capacity to produce an okay graphic vs. an excellent graphic,” says Arkin.
Next month, in the fourth installment of the series, we shall consider the finishing process: sewing, welding, and a fast-growing method of fabric finishing, specifically signage, silicone-edge graphics.