From the two previous installments of our own “Fabric Expert” series, we checked out the printing process, with an emphasis on dye-sublimation. In fabric printing, however, the phone case printer is just 50 % of the imaging equation. According to the ink you’re using, you will additionally need some kind 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 not good unless there is a heat press.” Next Wave offers each of the pieces 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 are also a distributor of EFI Reggiani fabric printing equipment.
Before we take a look at heat presses, let’s support a 2nd and talk for just a moment about transfer paper, an often overlooked but vitally important aspect of the dye-sublimation process.
Dye-sublimation transfer paper has a special coating that holds the ink laid down during printing. During the transfer stage, under exposure to heat and pressure, the paper releases that ink to the fabric. Dye-sublimation can be used on substrates aside from textiles, so you have to choose your transfer paper accordingly.
“You must be aware of the particular 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 instead of hard surfaces including ceramics, coffee mugs, or metal.”
You can find premium multipurpose papers-like Beaver Paper TexPrintXPHR-that happen to be works with both hard and soft substrates, which can be convenient if you’re offering many different dye-sub-printed products.
The quality of the paper will largely determine how much of ink gets released, but ink dye load is a crucial consideration. “Dye load” means exactly 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 acquire a given degree of color. Different transfer papers are thus formulated to be works with the dye load in the ink, which is usually a function of the brand name of the printer you will be using-or, that is certainly, the t-shirt printer manufacturer’s ink set.
Ideally, a transfer paper will release 90 % in the ink “stored” inside. There is absolutely no quantitative strategy to measure this, but if you locate you’re not getting all the ink out while you think you have to be, you may have to switch papers or adjust your color profiles. Alternatively, you might be releasing too much ink into the fabric, meaning you may well be putting a lot of ink on the paper to start with.
“There is a misconception of how much ink is absolutely needed,” says Repasi. “More ink doesn’t necessarily indicate more color. You’ll get a poor image by utilizing more ink than the paper are equipped for.” It’s all a subject of balance. “The appropriate amount of ink with all the right color management together with the right paper will generate the ideal output of color.”
Printed transfer paper doesn’t need to be sublimated immediately. Beaver Paper’s own internal experiments are finding that printed transfer paper can last for years. “We’ve transferred literally a couple of years later and it’s remarkably near to the original prints,” says Repasi. It can obviously be determined by the conditions under that your paper is stored. Still, in today’s fast-turnaround arena of digital printing, you’ll probably never must store transfer paper for even a couple of hours, but if you want to, it is possible to.
First a terminological note. We regularly begin to see the term calender – to never be confused spelling-wise with calendar (despite Autocorrect’s best efforts) – used along with dye-sublimation printing. What’s the difference from a calender plus a heat press?
“A calender press can be a rotating heated drum intended 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 will it be ideal for doing smaller piece goods.” A calender, then, can be a roll-to-roll heat press.
In a 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 filled with oil that is heated for 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 oil-filled calender will run you about $30,000 to $60,000, but will last for over 25 years.
There are more forms of cheaper calenders which use electric heating elements as opposed to oil, but a typical problem with them is inconsistent heat across the circumference or across the width of your drum. This will cause imaging problems or discoloration during sublimation which, in the end, is actually a careful balance of energy, temperature, and pressure. “If any one of those three changes, you simply will not have a consistent result,” said Arkin. “Color will not likely emerge the way it is supposed to. In case you have inconsistent heat in the press, the sublimation process will not be consistent throughout the entire component of fabric.”
Calenders have different width drums, which impact the press’s throughput. The greater the diameter in the drum, the more fabric may be wrapped around it, and consequently the faster the method will be.
Calenders transfer the fabric and transfer paper over a belt often made from Nomex. “The belt is really a critical area of the nice tight sandwich you require round the circumference of the drum,” says Arkin. “Cheaper machines have very thin belts, while good machines have belts that happen to be one-half to inch to three-quarters of any inch thick. Whether it doesn’t stay nice flat, sublimation gases can escape.” An increased-quality belt may last as much as five or six years. There are actually beltless calenders that are suitable for direct-to-fabric dye-sublimation, the place you don’t need to bother about transfer paper.
If you’re not sublimating rolls of fabric but instead cut pieces, the substitute for a calender is actually 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.
With a swing-away press, the upper platen, which supports the heating element, slides away left or right, making it considerably better 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 way back in place and also the heating element is brought down along with it. There are specialty heat presses that can accommodate stuff like mugs, plates, caps, along with other three-dimensional objects.
In most cases, a computerized timer can pop the press open after having 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 best and bottom that essentially “duplex” dye-sub transfer, which is wonderful for applying continuous graphics to both sides of, say, a T-shirt.
When it comes to deciding on a flatbed press, says Knight, “the product an individual is printing, and also the volume these are doing, will dictate which of those choices is suitable. Also, how big the item they can be printing will direct them towards several narrowed-down choices for heat presses.”
If you are using a flatbed heat press, you may need to use “tack” transfer paper, that has 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 while you are utilizing a roll-to-roll heat press, except if you’re sublimating onto a really elastic fabric which could stretch because it moves through the calender, causing a distorted image if it relaxes after cooling.
Should you be sublimating to highly stretchy fabric, you may have to make amends for stretch prior to printing. “You establish exactly what the shrink or stretch is perfect for a particular material, and you build those distortions into the files whenever you print them,” says Arkin. “Every time you handle that exact fabric type, you print it the same way so you receive a consistent result.” It’s a lot like color profiling, in many ways.
Even when you are doing direct-to-fabric instead of transfer-based dye-sublimation, you will still must run the printed fabric through a calender to repair the ink on the fibers of your polyester, and the same quality and consistency concerns apply.
Even if you’re printing with other kinds of dye or pigment inks – not sublimation -you will still need some type of pre- and/or post-management of the fabric. Reactive and acid dye inks require steaming after printing, then washing to take out excess ink. This can be one explanation why dye-sublimation is indeed attractive for fabric printing; these dexjpky05 ink types can require a great deal 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 a word, quality,” says Knight. “In the device world, particularly with heat presses that reach high temperatures and high pressures, you require one who will last decades, not merely months or a couple of years. A uv printer provides you with quality results and builds your company – an unsatisfactory press puts you of business.”
“The right heat press is exactly what separates you from being able to produce an okay graphic vs. an incredible graphic,” says Arkin.
The following month, inside the fourth installment on this series, we will glance at the finishing process: sewing, welding, plus a fast-growing kind of fabric finishing, specifically for signage, silicone-edge graphics.