Within 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 phone case printer is just 50 % of the imaging equation. Depending on the ink you’re using, additionally, you will need some sort of post-printing equipment to enhance 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 you have a heat press.” Next Wave offers all of the bits of a whole 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 take a look at heat presses, let’s back a second and talk for a second about transfer paper, an often overlooked but truly essential part of the dye-sublimation process.
Dye-sublimation transfer paper has a special coating that holds the ink laid down during printing. In the transfer stage, under being exposed to heat and pressure, the paper releases that ink on the fabric. Dye-sublimation works extremely well on substrates other than textiles, so you should choose your transfer paper accordingly.
“You must be mindful of the sort of paper you’re using,” says Rob Repasi, VP of Global Sales for Beaver Paper & Graphic Media. “There are papers which can be more inviting for textiles in contrast to hard surfaces such as ceramics, coffee mugs, or metal.”
There are actually premium multipurpose papers-like Beaver Paper TexPrintXPHR-which are appropriate for both hard and soft substrates, which is convenient if you’re offering a variety of dye-sub-printed products.
The grade of the paper will largely determine the amount of ink gets released, but ink dye load is a crucial consideration. “Dye load” means just how much colorant (dye) the ink contains relative to the liquid vehicle. The larger the dye load, the less ink you should lay out to obtain a given degree of color. Different transfer papers are thus formulated to get appropriate for the dye load from the ink, which is usually a function of the make and model from the printer you are using-or, that may be, the dtg printer manufacturer’s ink set.
Ideally, a transfer paper will release 90 % in the ink “stored” inside it. There is absolutely no quantitative approach to measure this, but if you locate you’re not getting all the ink out while you think you ought to be, you may need to switch papers or adjust your color profiles. Alternatively, you may be releasing too much ink into the fabric, which means you might be putting an excessive amount of ink to the paper to begin with.
“There can be a misconception of methods much ink is actually needed,” says Repasi. “More ink doesn’t really mean more color. You’ll end up with a bad image by utilizing more ink compared to paper are equipped for.” It’s all a question of balance. “The proper amount of ink with all the right color management with the right paper will generate the perfect output of color.”
Printed transfer paper doesn’t must be sublimated immediately. Beaver Paper’s own internal experiments have realized that printed transfer paper may last for years. “We’ve transferred literally a year or so later and it’s remarkably next to the original prints,” says Repasi. It would obviously depend 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 for several hours, but if you wish to, you are able to.
First a terminological note. We regularly begin to see the term calender – not to be confused spelling-wise with calendar (despite Autocorrect’s best efforts) – used along with dye-sublimation printing. What’s the difference between 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 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 able to pressing rigid materials, nor is it appropriate for doing smaller piece goods.” A calender, then, is actually a roll-to-roll heat press.
Within a calender, heat is produced in a central drum against that the fabric and paper are pressed. The best-quality calenders have got a central drum full of oil that is heated on the desired temperature necessary for sublimation, typically within the neighborhood of 400°F. The transfer paper/fabric sandwich is rolled around this drum at the set rate which is, again, optimal for sublimation. A top-notch oil-filled calender will run you about $30,000 to $60,000, but will last for greater than 25 years.
There are other sorts of more affordable calenders that use electric heating elements instead of oil, but a typical issue with them is inconsistent heat round the circumference or all over the width of the drum. This can cause imaging problems or discoloration during sublimation which, in the end, is a careful balance of time, temperature, and pressure. “If any some of those three changes, you simply will not have a consistent result,” said Arkin. “Color will not appear the way it should really. In case you have inconsistent heat on the press, the sublimation process is definitely not consistent all over the entire component of fabric.”
Calenders have different width drums, which affect the press’s throughput. The larger the diameter from the drum, the better fabric could be wrapped around it, and therefore the faster this process will likely be.
Calenders transfer the material and transfer paper with a belt often created from Nomex. “The belt is actually a critical part of the nice tight sandwich you want across the circumference from the drum,” says Arkin. “Cheaper machines have very thin belts, while good machines have belts which are one-half to inch to 3-quarters of your inch thick. If it doesn’t stay nice flat, sublimation gases can escape.” A very high-quality belt can last as much as five or six years. There are actually beltless calenders that are compatible with direct-to-fabric dye-sublimation, the place you don’t have to bother about transfer paper.
If you’re not sublimating rolls of fabric but instead cut pieces, the replacement for a calender can be a flatbed heat press. Flatbeds are also made of several varieties:
A clamshell opens and closes like its namesake, squeezing the paper and fabric together.
On a swing-away press, the top platen, which holds the heating element, slides away on the left or right, so that it is a lot better than a clamshell for thicker substrates.
A drawer press features a front-loading lower platen that, if the fabric and paper are loaded, slides back in place along with the heating element is brought down along with it. There are also specialty heat presses that may accommodate things like mugs, plates, caps, as well as other three-dimensional objects.
Generally, an automated timer can pop the press open after having a desired transfer time to prevent overheating, particularly if an operator is attending to multiple presses.
There are actually newer “all over sublimation” flatbed heat presses with heating elements for both the top 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 choosing a flatbed press, says Knight, “the product the user is printing, and the volume these are doing, will dictate which of those choices is appropriate. Also, the actual size of the goods they may be printing will direct them towards a couple of narrowed-down alternatives 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 touch with the material so there is no shifting throughout the sublimation process, that may cause blurring or ghosting. Tack paper isn’t usually required if you are employing a roll-to-roll heat press, except if you’re sublimating onto a really elastic fabric which can stretch since it moves from the calender, creating a distorted image when it relaxes after cooling.
When you are sublimating to highly stretchy fabric, you might need to make up for stretch prior to printing. “You establish just what the shrink or stretch is made for a particular material, and you build those distortions into the files whenever you print them,” says Arkin. “Every time you handle that particular fabric type, you print it exactly the same way so you have a consistent result.” It’s a lot like color profiling, in such a way.
Even if you are doing direct-to-fabric as opposed to transfer-based dye-sublimation, you will still need to run the printed fabric through a calender to correct the ink to the fibers of the polyester, and the same quality and consistency concerns apply.
Regardless of whether you’re printing with other kinds of dye or pigment inks – not sublimation -you still need some sort of pre- and/or post-treatment of the material. Reactive and acid dye inks require steaming after printing, then washing to take out excess ink. This can be one reason that dye-sublimation is very attractive for fabric printing; these dexjpky05 ink types can require a lot of water.
No matter the specific configuration of warmth press, you don’t wish to skimp on quality. “Look for same-day support and longevity; within a word, quality,” says Knight. “In the equipment world, especially with heat presses that reach high temperatures and high pressures, you will need one who will last decades, not merely months or a couple of years. A A4 UV Printer offers you quality results and builds your business – an unsatisfactory press puts you out of business.”
“The right heat press is the thing that separates you against being able to produce an okay graphic vs. a fantastic graphic,” says Arkin.
The following month, from the fourth installment of this series, we are going to consider the finishing process: sewing, welding, plus a fast-growing form of fabric finishing, specifically for signage, silicone-edge graphics.