This is commonly referred to as Partial Powder Attachment in DTF films. While at first glance this may seem like a minor issue, this problem can affect the clarity and smoothness of the final transfer. So what can we do to fix it?
What Is Partial Powder Adhesion In DTF Film?
Partial Powder Adhesion In DTF Film refers to the unwanted sticking of hot melt powder on sections of the film where there is no ink. You’ll typically see this as cloudy patches or speckled zones in otherwise clean areas—most often right after the printer has been idle overnight or during the first few prints of the day.
If you don’t pay attention to it, it can make already printed films appear sticky on the back. For more information on the phenomenon of sticky backs, you can read: What Causes Back Sticking In DTF Roll Film
If you’re not careful, this can leave stains after the transfer. As you can see in the image below, a perfectly good print has been ruined!
Why Does Partial Powder Adhesion In DTF Film Happen?
There are a couple of common culprits behind this issue:
Moisture Exposure: If your film wasn’t stored in a sealed environment, it may have absorbed humidity from the air. This dampness can make the surface more attractive to powder.
In some regions, the significant temperature difference between day and night can easily lead to moisture. If the film remains in the printer awaiting a second print job in such conditions, this issue may arise.
Moist Hot Melt Powder: Sometimes, the powder itself has absorbed moisture, especially if it’s been handled often. You can check this by feeling for clumps or a slightly damp texture.
Damp powder may not be all the way damp, it may only be partly so. The shaking during your use may cause the otherwise damp powder to bury itself, creating a hidden problem later.
In my previous blog posts, I also mentioned the possibility of powder adhesion. See also: DTF Powder “Sticky Powder” Phenomenon Causes And Solutions
How To Troubleshoot And Solve Partial Powder Adhesion In DTF Film
Here are a few practical steps to help you prevent or fix this issue:
1. Check Humidity In Your Workroom
High humidity levels can contribute to both film and powder absorbing moisture. Try to keep the room below the recommended maximum humidity. If it gets too humid, use a dehumidifier.
By the way, all DTF consumables are quite sensitive to temperature and humidity. To ensure proper use, you’ll need to maintain a working environment free of these issues, both during storage and active use. See: Effects of Improper Storage DTF Supplies
2. Extend Film Beyond The Edges Before Printing
Cut the film to extend 2–3cm beyond the design area before printing. This can help isolate problematic edges that might hold more moisture.
This approach is equivalent to excluding the portion of the film that remains in the printer. This method is for testing and inspection only and is not recommended for long-term use, as it is too wasteful.
3. Pre-Heat The Film If Slightly Affected
If the film feels just a bit moist, consider pre-heating it before shaking powder onto it. This makes it less likely to attract powder in blank areas.
Most thin films are resistant to high temperatures. As long as you avoid exposing them to excessively high temperatures, you can use a specific temperature range to “pre-bake” them.
4. Bake Damp Powder Before Use
If you suspect the powder is the issue, bake it at 30 minutes in a low-heat oven to dry it out before using. After baking, use a mesh sieve to distribute the powder evenly.
It’s important to remember the goal here is to improve the issue of potential powder clumping due to moisture. Therefore, when it comes to temperature settings, just adjust them to an appropriate range.
Preventing Future Issues With Partial Powder Adhesion In DTF Film
To keep this problem from recurring, always:
- Store your DTF films in sealed, moisture-proof bags. And it’s best not to leave unused film in the printer. More ways to store film can be viewed: DTF Films Storage Guide
- Keep the hot melt powder in airtight containers with desiccant packs. To facilitate troubleshooting, avoid moisture exposure to both the hot melt adhesive powder and the film as much as possible.
- Print test runs after long machine idle periods to ensure stable output. Performing similar moves on your printer on a regular basis is a form of maintenance for the printer itself.
- Consider investing in a humidity sensor to monitor your workshop’s air conditions consistently. Please tailor this to your specific situation.