August 10, 2020
Important note: If you are new to transfers, please first read the blog “Beginner’s Guide to Transfers” before continuing on through this blog.
The world of screen printing hot peel transfers can be a lot of fun as there are so many different looks and feels you can achieve. There are a number of hot peel papers to choose from. You can choose between adhesive powders, printable adhesives, and no adhesive whatsoever. You can print with a transfer ink or your everyday plastisol for direct printing. The real trick is knowing how to make all of this work together. Conveyor dryer settings along with heat press settings will be key to your successes.
Let’s start with the idea of printing hot peel transfers without any adhesive. To do this, you need a particular ink. 380 Series is our hot split/hot peel transfer ink for this situation. Since you are not printing with a powder or liquid adhesive, the ink in combination with the correct conveyor dryer speed/temperature is critical. The goal here is to “gel” the ink to the paper. You don’t want it fully cured. You simply want the top dry to the touch. This is best achieved with a short dryer dwell time. Speed the conveyor belt up and only heat the ink for 10-15 seconds. Find the temperature that the ink comes out wet and slow the belt down just a little at a time until it is dry to the touch.
Heat press settings are very important as the ink truly must melt into the fabric. Otherwise the transfer won’t adhere after a few wash cycles. 375ºF for 8-12 seconds and firm pressure is generally where you need to be. The shorter time is for thinner fabrics. Heavier fabrics will require more time. You will also want to peel somewhat quickly after the heat press is lifted.
The pros of hot peel transfers without any adhesive is simply speed of printing and the lighter feel on the fabric. The cons are less opacity and bleed resistance. These transfers will also not be nearly as durable as one with a powder or liquid adhesive. We don’t typically recommend these transfers for anything more than a give away tee. There are simply better ways that you are about to learn about.
Using a printable adhesive is a second method for hot peel transfers. This is very popular as the prints are more durable, the application temperature is lower, and there is less mess than a powder adhesive. All of the printing and gelling steps discussed earlier still remain except you will print the final layer of this printable adhesive over the entire print. One item to be very conscious of is your mesh counts. If you have a detailed transfer using a bunch of fine mesh counts, you will want to use a coarse mesh with the printable adhesive. Perhaps an 86 or 110 count mesh makes the most sense. This will make the print very stretchy and durable in the wash.
Application settings with a printable adhesive do vary. We recommend 350ºF for 8-10 seconds, firm pressure. Some companies advertise temperatures as low as 330ºF with a printable adhesive but we don’t feel confident with this temperature unless the time is extended quite a bit. For us, it isn’t worth the risk unless you have tested this well.
Finally, we have the preferred method of hot peel transfers. This is a transfer using powder adhesives. This powder is applied to the wet print of the final color and then sent through the conveyor dryer. There are numerous benefits to doing it this way. The opacity, bleed resistance, durability, and stretch will be the highest when printing this way. Also, you have a lot more flexibility with gel temperature and time. The powder adhesive almost makes the process “dummy proof”. It simply works better.
With all of the benefits come a few drawbacks. This is a little bit messy. The powder can get up in the air and all over everything. This is a real problem, especially when static is high and the powder wants to stick to the paper where it isn’t supposed to be. This leaves a stain. You must apply the powder by dipping the transfer through the powder and shaking it off really well. Some of our customers use an anti-static bar to make this easier. It will take the static from the paper and the powder just falls off the sheet.
Another drawback comes with the situation that you only powder the final color of the print. What if the final color isn’t a white base that encompasses the whole design? You can print a clear ink under everything and then powder this ink as the final step. Even though it is an extra screen, the benefits are very much there. Adding the clear ink plus the powder adhesive gives you even more guarantee that the print will be durable, stretchy, opaque, and bleed resistant.
There are numerous types of powder adhesive. Some are very stretchy and soft. Others are very bleed resistant and adhere to slick fabrics. They are much like ink, they all have their own traits that make them good or bad for certain things. Luckily, we can guide you to the best adhesive for you. Most people only need to stock one.
Application with a powdered hot peel transfer can vary wildly depending on the ink, powder, and paper. You can create a transfer that can be applied at 300ºF for 8 seconds all the way up to 375ºF for 12 seconds. If you are gelling the ink at a low temperature, using our Soft Peel paper, transfer ink, and our lowest temperature powder adhesive, you can apply at the lowest setting with success. If you change the paper, powder, ink, or process, this will only bring your application setting higher. Just a for instance, using the Soft Peel paper, low temperature powder, but changing the ink to a non-transfer ink, you are now likely applying at 300ºF for 10-12 seconds. The difference is how non-transfer inks “grab” onto the transfer paper. They simply don’t release as easily.